novel approaches in textile surface modifications for

1

UNIVERSITY OF MANCHESTER

Novel approaches in textile surface modifications for better

printability A thesis submitted to the University of Manchester for the degree of Doctor of Philosophy in

The Faculty of Sciences and Engineering

2018

Rasha Salaheldien Aboelenien Eldesoky

2

Table of contents

Abstract…………………...……...………………………………………………………….25

Declaration.............................................................................................................................. 26

Copyright Statement .............................................................................................................. 27

Acknowledgments .................................................................................................................. 28

1. Chapter One: Introduction .......................................................................................... 29

1.1. Aim of work ................................................................................................................. 29

1.2. Thesis layout ................................................................................................................. 30

2. Chapter Two: Literature review ................................................................................. 31

2.1. Textiles ......................................................................................................................... 31

2.2. Classification of fibres .................................................................................................. 31

2.2.1. Natural fibres ................................................................................................................ 31

2.2.1.1. Cotton ................................................................................................................... 31

2.2.1.2. Chemical properties of cotton .............................................................................. 32

2.2.2. Manufactured fibres...................................................................................................... 35

2.2.2.1. Polyester ............................................................................................................... 35

2.2.2.2. Production of polyester ........................................................................................ 36

2.2.2.3. Chemical properties of polyester ......................................................................... 36

2.2.2.4. Polyester surface treatments................................................................................. 37

2.3. Colouration ................................................................................................................... 38

2.3.1. What is colour and how do we see it? .......................................................................... 38

2.3.2. Colour measurements ................................................................................................... 39

2.4. Textile colouration........................................................................................................ 40

2.4.1. Textile dyeing ............................................................................................................... 40

2.4.2. Textile printing ............................................................................................................. 40

2.4.2.1. Textile printing styles .......................................................................................... 41

2.5. Textile colourants ......................................................................................................... 42

2.5.1. Pigments ....................................................................................................................... 42

2.5.2. Textile dyes .................................................................................................................. 42

2.5.2.1. Acid dyes ............................................................................................................. 42

2.5.2.2. Acid dyes classification ....................................................................................... 43

2.5.2.3. Dyeing process of acid dyes................................................................................. 44

2.5.3. Colouring polyester ...................................................................................................... 45

2.6. Chitosan ........................................................................................................................ 45

3

2.6.1. The use of chitosan in colouration of different textile materials .................................. 48

2.6.1.1. Colouration of polyester with chitosan ................................................................ 48

2.6.1.2. Coloration of cotton fabrics with chitosan ........................................................... 49

2.7. Previous publications in chitosan treatments of textile fabrics .................................... 49

2.8. Chitosan treatments on cotton ...................................................................................... 50

2.8.1. Chitosan treatments to improve antimicrobial properties ............................................. 50

2.8.2. Chitosan treatments to improve mechanical properties ................................................ 53

2.8.3. Chitosan treatments to improve dyeability ................................................................... 54

2.8.4. Chitosan treatments to improve textile printability ...................................................... 56

2.8.5. Nano chitosan on cotton ............................................................................................... 57

2.9. Chitosan treatments on wool ........................................................................................ 57

2.9.1. Chitosan treatments to improve antimicrobial properties ............................................. 57

2.9.2. Chitosan treatments to improve mechanical properties ................................................ 58

2.9.3. Chitosan treatments to improve dyeability ................................................................... 61

2.9.4. Chitosan treatments to improve printability ................................................................. 64

2.9.5. Nano-chitosan treatment for wool ................................................................................ 64

2.10. Chitosan treatment for polyester .................................................................................. 65

2.10.1. Chitosan treatments to improve the antimicrobial properties ....................................... 65

2.10.2. Chitosan treatments to improve textile mechanical properties ..................................... 66

2.10.3. Chitosan treatments to improve textile dyeability ........................................................ 67

2.10.4. Chitosan treatments to improve printability ................................................................. 68

2.11. Chitosan treatment on cotton / polyester blends ........................................................... 69

3. Chapter Three: Methodology ...................................................................................... 71

3.1. Introduction .................................................................................................................. 71

3.2. Materials ....................................................................................................................... 72

3.2.1. Fabrics .......................................................................................................................... 72

3.2.2. Chemicals ..................................................................................................................... 72

3.3. Apparatus ...................................................................................................................... 72

3.4. Design of experiments .................................................................................................. 73

3.4.1. Part one: Using the padding process to improve the dyeability of cotton, polyester, and

cotton/polyester blends. ................................................................................................................ 73

3.4.2. Part two: Using chitosan in producing differential printings on different textile

materials ...................................................................................................................................... 74

3.4.3. Part three: The use of chitosan in producing resist printing on different textile

materials ...................................................................................................................................... 74

3.5. Repeated procedures ..................................................................................................... 75

4

3.5.1. Fabric preparation ......................................................................................................... 75

3.5.2. Polyester and poly/cotton pretreatment (polyester hydrolysis) .................................... 75

3.5.3. Chitosan preparation ..................................................................................................... 75

3.5.4. Chitosan application techniques on the studied textile samples ................................... 76

3.5.4.1. The application of chitosan using padding technique .......................................... 76

3.5.4.2. Using silkscreen printing technique for chitosan application on textile fabrics... 76

3.5.5. Dyeing process ............................................................................................................. 76

3.6. Samples analysis ........................................................................................................... 77

3.6.1. Colour evaluation ......................................................................................................... 77

3.6.2. Colour fastness evaluations .......................................................................................... 77

3.6.2.1. Colour fastness to crocking .................................................................................. 77

3.6.2.2. Colour fastness to domestic and commercial laundering ..................................... 78

3.6.2.3. Colour fastness to perspiration ............................................................................. 78

3.6.2.1. Scanning Electron Microscope analysis .............................................................. 80

3.7. Statistical analysis ........................................................................................................ 80

4. Chapter Four: Using the padding process to improve the dyeability of cotton,

polyester, and cotton/polyester blends .............................................................................. 84

4.1. Introduction .................................................................................................................. 84

4.2. Initial experimental approaches .................................................................................... 85

4.2.1. The optimum temperature for sodium hydroxide NaOH pretreatment of polyester .... 85

4.2.2. Effect of increasing chitosan of low molecular weight concentration on the colour

strength of polyester samples ........................................................................................................ 85

4.2.3. The use of pad- dry- cure process instead of exhaustion process for chitosan treatment .

...................................................................................................................................... 86

4.2.4. The use of high molecular weight vs. low molecular weight chitosan ......................... 87

4.2.5. The use of basic dyes .................................................................................................... 87

4.2.6. The use of chitosan with di methylol di hydroxy ethylene urea DMDHEU compared to

the use of chitosan with acetic acid ............................................................................................... 88

4.2.7. Polymer loading calculation ......................................................................................... 89

4.3. Experiments ............................................................................................................................... 91

4.3.1. Chitosan treatment ........................................................................................................ 91

4.3.2. Dyeing with acid dyes .......................................................................................... 91

4.3.3. Samples evaluation .............................................................................................. 91

4.3.3.1. Colour strength evaluation ................................................................................... 91

4.3.3.2. Colour fastness to crocking .................................................................................. 91

4.3.3.3. Colour fastness to perspiration ............................................................................. 92

4.3.3.4. Colour fastness to domestic and commercial laundering ..................................... 92

5

4.4. Results and discussions ................................................................................................ 92

4.4.1. Effect of sodium hydroxide concentration on the K/S values of chitosan padded textile

fabrics ...................................................................................................................................... 92

4.4.1.1. Effect of sodium hydroxide concentration on the K/S values of PET samples ... 92

4.4.1.2. Effect of Sodium hydroxide concentration on the K/S values of 50% cotton- 50%

PET samples ............................................................................................................................. 94

4.4.1.3. Effect of sodium hydroxide concentration on the K/S values of 65% cotton- 35%

PET samples ............................................................................................................................. 96

4.4.2. Effect of chitosan fixation temperature on K/S values of chitosan padded textile fabrics

...................................................................................................................................... 98

4.4.2.1. Effect of chitosan fixation temperature on the K/S values of PET samples ........ 99

4.4.2.2. Effect of fixation temperature on the K/S values of 50% Cotton- 50% PET

samples ........................................................................................................................... 101

4.4.2.3. Effect of fixation temperature on the K/S values of 65% cotton- 35% PET

samples ........................................................................................................................... 103

4.4.2.4. Effect of fixation temperature on the K/S values of cotton samples .................. 104

4.4.3. Effect of chitosan fixation time on the K/S values of chitosan padded textile fabrics106

4.4.3.1. Effect of fixation time on the K/S values of PET samples ................................ 106

4.4.3.2. Effect of fixation time on the K/S values of 50% cotton – 50% PET samples .. 108


4.4.3.4. Effect of fixation time on the K/S values of cotton samples .............................. 112

4.4.4. Effect of chitosan concentration on the K/s values of chitosan padded textile fabrics.....

.................................................................................................................................... 113

4.4.4.1. Effect of chitosan concentration on the K/S values of PET samples ................. 114

4.4.4.2. Effect of chitosan concentration on the K/S values of 50% Cotton- 50% PET

samples ........................................................................................................................... 115

4.4.4.3. Effect of chitosan concentration on the K/S values of 65% cotton- 35% PET

samples ........................................................................................................................... 117

4.4.4.4. Effect of chitosan concentration on the K/S values of cotton samples .............. 119

4.4.4.5. Multiple ANOVA analysis for the effect of chitosan concentration .................. 120

4.5. Samples Evaluation .................................................................................................... 121

4.5.1. Colour fastness evaluation .......................................................................................... 121

4.5.1.1. Colour fastness to crocking ................................................................................ 121

4.5.1.2. Colour fastness to domestic and commercial laundering ................................... 123

4.5.1.3. Colour fastness to perspiration ........................................................................... 124

4.5.2. Scanning Electron Microscope (SEM) ....................................................................... 127

4.6. Conclusion .................................................................................................................. 130

6

Chapter Five: Differential printing of cotton, polyester, and cotton/polyester blends with

chitosan. ............................................................................................................................. 131

5.1. Introduction ................................................................................................................ 131

5.2. Experiments ................................................................................................................ 132

5.2.1. Materials ..................................................................................................................... 132

5.2.2. Methods ...................................................................................................................... 132

5.2.2.1. Polyester and Polyester/ cotton blends pretreatment ......................................... 132

5.2.2.2. Fabric treatment with chitosan ........................................................................... 132

5.2.2.3. Dyeing of printed samples ................................................................................. 133

5.2.2.4. Samples evaluation ............................................................................................ 133

5.3. Results and discussion ................................................................................................ 134

5.3.1. Effect of sodium hydroxide concentration in the pretreatment of chitosan printed

textile fabrics ............................................................................................................................... 134

5.3.1.1. Effect of sodium hydroxide concentration on the K/S values of PET samples . 134

5.3.1.2. Effect of Sodium hydroxide concentration on the K/S values of 50% Cotton-

50% PET samples ................................................................................................................... 137

5.3.1.3. Effect of sodium hydroxide concentration on the K/S values of 65% cotton- 35%

PET samples ........................................................................................................................... 138

5.3.1.4. Multiple ANOVA analysis for the effect of NaOH concentration..................... 140

5.3.2. Effect of chitosan fixation temperature on the K/S values of chitosan printed textile

fabrics .................................................................................................................................... 141

5.3.2.1. Effect of chitosan fixation temperature on the K/S values of chitosan printed PET

samples ........................................................................................................................... 142

5.3.2.2. Effect of fixation temperature on the K/S values of chitosan printed 50% cotton-

50% PET samples ................................................................................................................... 144

5.3.2.3. Effect of fixation temperature on the K/S values of chitosan printed 65% Cotton-

35% PET samples ................................................................................................................... 145

5.3.2.4. Effect of fixation temperature on the K/S values of cotton samples .................. 147

5.3.2.5. Multiple ANOVA analysis for the effect of fixation temperature of K/S for the

textile samples ......................................................................................................................... 149

5.3.3. Effect of chitosan fixation time on chitosan printed textile samples .......................... 150

5.3.3.1. Effect of fixation time on the K/S values of chitosan printed PET samples ...... 150



5.3.3.4. Effect of fixation time on the K/S values of cotton samples .............................. 156

5.3.3.5. Multiple ANOVA analysis for the effect of fixation time on K/S values of treated

samples ........................................................................................................................... 158

7

5.3.4. Effect of chitosan concentration on the K/S values of chitosan printed textile fabrics ....

.................................................................................................................................... 159

5.3.4.1. Effect of chitosan concentration on the K/S values of PET samples ................. 159


samples ........................................................................................................................... 161


samples ........................................................................................................................... 163

5.3.4.4. Effect of chitosan concentration on the K/S values of cotton samples .............. 165

5.3.4.5. Multiple ANOVA analysis for the effect of chitosan concentration .................. 166

5.4. Samples evaluation ..................................................................................................... 167

5.4.1. Colour fastness evaluation .......................................................................................... 167

5.4.1.1. Colour fastness to crocking ................................................................................ 167

5.4.1.2. Colour fastness to domestic and commercial laundering ................................... 169

5.4.1.3. Colour fastness to perspiration ........................................................................... 170

5.4.2. Scanning Electron Microscope (SEM) ....................................................................... 175

5.5. Conclusion .................................................................................................................. 178

6. Chapter Six: A novel approach in resist printing of polyester and polyester/cotton

blended fabrics .................................................................................................................. 179

6.1. Introduction ................................................................................................................ 179

6.2. Initial experimental approaches .................................................................................. 180

4.6.1. The use of chitosan in discharge printing of PET fabrics and its blends .................... 180

6.2.2. The use of thermo-fixation vs. steam-fixation for resist printing with NaOH and

chitosan .................................................................................................................................... 181

6.3. Experiments ................................................................................................................ 182

6.3.1. Materials ..................................................................................................................... 182

6.3.2. Methods ...................................................................................................................... 182

6.3.2.1. Polyester and poly/cotton pretreatment .............................................................. 182

6.3.2.2. Resist printing .................................................................................................... 182

6.3.2.3. Chitosan printing ................................................................................................ 182

6.3.2.4. Dyeing of printed samples ................................................................................. 183

6.3.2.5. Washing ............................................................................................................. 183

6.3.2.6. Samples evaluation ............................................................................................ 184

6.4. Results and discussion ................................................................................................ 184

6.4.1. Effect of chitosan fixation temperature on the K/S values of chitosan printed textile

fabrics .................................................................................................................................... 184

6.4.1.1. Effect of fixation temperature on the percentage decrease in K/S values of resist

printed PET samples ............................................................................................................... 184

8


printed 50 % cotton – 50 % PET samples ............................................................................... 186


printed 65 % cotton – 35 % PET samples ............................................................................... 188

6.4.2. Effect of chitosan fixation time on the K/S values of chitosan printed textiles .......... 190


printed PET samples ............................................................................................................... 190

6.4.2.2. Effect of fixation time on the percentage decrease in K/S values of resist printed

50 % cotton – 50 % PET samples ........................................................................................... 192

6.4.2.3. Effect of fixation time on the percentage decrease in K/S values of resist printed

65 % cotton – 35 % PET samples ........................................................................................... 194

6.4.3. Effect of sodium hydroxide concentration in resist printing paste on the percentage

decrease in K/S values of resist printed textile samples ............................................................. 196

6.4.3.1. Effect of sodium hydroxide concentration on the percentage decrease in K/S

values of resist printed PET samples ...................................................................................... 196


values of resist printed 50% cotton – 50% PET samples ........................................................ 198


values of resist printed 65 % cotton – 35% PET samples ....................................................... 200

6.5. Samples evaluation ..................................................................................................... 202

6.5.1. Scanning electron microscope (SEM) ........................................................................ 202

6.6. Conclusion .................................................................................................................. 205

Chapter seven: Conclusion and further research ............................................................. 206

7.1. Conclusion .................................................................................................................. 206

7.2. Further research .......................................................................................................... 207

8. References .................................................................................................................... 209

9. Appendix A: ................................................................................................................. 217

Data analysis for using the padding process to improve the dyeability of cotton, polyester,

and cotton/polyester blends .............................................................................................. 217

9.1. Effect of Chitosan concentration ................................................................................ 217

9.1.1. Effect of chitosan concentration on polyester samples............................................... 217

9.1.2. Effect of chitosan concentration on 50% cotton - 50% PET (Blend 1) samples ........ 219

9.1.3. The effect of chitosan concentration on 65% cotton-35%PET (Blend 2) samples .... 220

9.1.4. The effect of chitosan concentration on cotton samples ............................................. 222

9.2. Effect of chitosan fixation temperature ...................................................................... 224

9.2.1. The effect of fixation temperature on PET samples ................................................... 224

9.2.2. The effect of fixation temperature on 50% cotton - 50% PET (Blend 1) samples ..... 225

9.2.3. The effect of fixation temp on 65% cotton - 35% PET (Blend 2) samples ................ 227

9

9.2.4. The effect of fixation temperature on cotton samples ................................................ 229

9.3. Effect of chitosan fixation Time ................................................................................. 230

9.3.1. The effect of fixation time on PET samples ............................................................... 230

9.3.2. The effect of fixation time on 50% cotton - 50% PET (Blend 1) samples ................. 232


9.3.4. The effect of fixation time on cotton samples ............................................................ 235

9.4. Effect of NaOH concentration .................................................................................... 236

9.4.1. The effect of NaOH concentration on PET samples .................................................. 236

9.4.2. The effect of NaOH concentration on 50% cotton - 50% PET (Blend 1) samples .... 238


Appendix B: Data analysis for differential printing of cotton, polyester, and

cotton/polyester blends with chitosan. ............................................................................ 242

10.1. Effect of NaOH concentration .................................................................................... 242




10.2. Effect of Temperature ................................................................................................. 247

10.2.1. The effect of fixation temperature on PET samples ................................................... 247



10.2.4. The effect of fixation temperature on cotton samples ................................................ 252





10.3.4. The effect of fixation time on cotton samples ............................................................ 258

10.4. Effect of chitosan concentration ................................................................................. 259

10.4.1. The effect of chitosan concentration on PET samples ............................................... 259

10.4.2. The effect of chitosan concentration on 50 % cotton - 50% PET (Blend 1) samples 261

10.4.3. The effect of chitosan concentration on 65 % cotton – 35 % PET (Blend 2) samples .....

.................................................................................................................................... 262

10.4.4. The effect of chitosan concentration on cotton samples ............................................. 264

11. Appendix C: Data analysis for the resist printing of polyester and polyester/cotton

blended fabrics .................................................................................................................. 267

11.1. Effect of chitosan fixation temperature ...................................................................... 267

11.1.1. The effect of chitosan fixation temperature on PET samples ..................................... 267

10

11.1.2. The effect of fixation temperature on 50 % cotton - 50% PET (Blend 1) samples .... 269

11.1.3. The effect of fixation temperature on 65 % cotton - 35% PET (Blend 2) samples .... 270



11.2.2. The effect of fixation time on 50 % cotton - 50% PET (Blend 1) samples ................ 273

11.2.3. The effect of fixation time on 65 % cotton - 35% PET (Blend 2) samples ................ 274

11.3. Effect of NaOH concentration in the resist printing paste .......................................... 276


11.3.2. The effect of NaOH concentration on 50 % cotton - 50% PET (Blend 1) samples ... 278

11.3.3. The effect of NaOH concentration on 65 % cotton - 35% PET (Blend 2) samples ... 279

Words count 71094

11

List of figures

Figure 2.1: Chemical structure of cellulose ............................................................................. 31

Figure 2.2: Scanning electron micrographs of raw cotton fibres ............................................. 32

Figure 2.3: Cotton reaction with acids ..................................................................................... 33

Figure 2.4: Oxidation of cotton ................................................................................................ 34

Figure 2.5: Chemical structure of PET ................................................................................... 35

Figure 2.6: Syntheses of polyethylene terephthalate ............................................................... 36

Figure 2.7: Alkaline hydrolysis of PET ................................................................................... 37

Figure 2.8: A double beam reflection spectrophotometers ...................................................... 40

Figure 2.9: Reaction between a cationic fibre and the acid dye ............................................. 43

Figure 2.10: Crustacean sources of chitin ............................................................................... 46

Figure 2.11: The deacetylation of chitin ................................................................................. 46

Figure 2.12: Chemical structure of chitosan ........................................................................... 47

Figure 2.13: Chitosan dissolution in acetic acid ..................................................................... 47

Figure 2.14: SEM of untreated cotton fibres .......................................................................... 52

Figure 2.15: SEM of chitosan/DMDHEU treated cotton fibres ............................................. 52

Figure 2.16: Wool fibre treated with bactosol enzyme for 60 min. ........................................ 59

Figure 2.17: Wool fibre treated with esperase enzyme for 60 min. ........................................ 59

Figure 2.18: Wool fibre treated with chitosan and bactosol enzyme for 60 min. ................... 60

Figure 2.19: Wool fibre treated with chitosan and esperase enzyme for 60 min. ................... 60

Figure 3.1: Means and standard errors for the effect of fixation temperature on the K/S values

of the chitosan padded cotton samples ........................................................................... 82

Figure 3.2: Plot of fitted model illustrating the effect of fixation temperature on the K/S

values of the chitosan padded cotton samples ................................................................. 83

Figure 4.1: Samples for initial trials of effect of increasing chitosan of low molecular weight

concentration on the colour strength of polyester samples ............................................... 86

Figure 4.2: Samples of initial trails for the use of pad- dry- cure process instead of the

exhaustion process for chitosan treatment ....................................................................... 87

Figure 4.3: Samples of initial trails for the use of basic dye ................................................... 88

Figure 4.4: Samples of initial trials for the use of chitosan with DMDHEU .......................... 88

Figure 4.5: Successful sample of polyester fabric padded in chitosan and dyed with acid dye ..

89

Figure 4.6: Effect of NaOH concentration on the k/s values of the chitosan padded PET

samples ............................................................................................................................. 93

Figure 4.7: Standard errors for the effect of NaOH concentration on the K/S values of the

chitosan padded 50% cotton – 50% PET samples ........................................................... 95


chitosan padded 65% cotton – 35% PET samples ............................................................ 97


of the chitosan padded PET samples ................................................................................ 99

Figure 4.10: Effect of fixation temperature on the K/S values of the chitosan padded 50%

cotton – 50% PET samples ……………………………………………….…… 101

12

Figure 4.11: Means and standard errors for the effect of fixation temperature on the K/S

values of the chitosan padded 65% cotton – 35% PET samples .................................... 103


values of the chitosan padded cotton samples……………………..…….…… 105

Figure 4.13: Means and standard error for the effect of fixation time on the K/S values of the

chitosan padded PET samples ....................................................................................... 107


chitosan padded 50% cotton – 50% PET samples ......................................................... 108

Figure 4.15: Means and standard error for the effect of fixation time on the K/S values of

the chitosan padded 65% cotton – 35% PET samples ................................................... 110


chitosan padded cotton samples .................................................................................... 112

Figure 4.17: Means and standard error for the effect of chitosan concentration on the K/S

values of the chitosan padded PET samples .................................................................. 114


values of the chitosan padded 50% cotton- 50% PET samples ..................................... 116


values of the chitosan padded 65% cotton- 35% PET samples

………………………………………...………………………………………….…… 118

Figure 4.20: Means and standard errors for the effect of chitosan concentration on the K/S

values of the chitosan padded cotton samples ............................................................... 119

Figure 4.21 Means and standard errors for the comparison between chitosan concentration

effects on different fabrics ............................................................................................. 121

Figure 4.22: SEM for un treated PET sample ...................................................................... 127

Figure 4.23: SEM for PET sample treated with chitosan at the optimum condition .................. 127

Figure 4.24: SEM for un treated 50% cotton – 50% PET sample ....................................... 128

Figure 4.25: SEM for 50% cotton – 50% PET sample treated with chitosan at the optimum

condition ........................................................................................................................ 128


Figure 4.27: SEM for 65% cotton – 35% PET sample treated with chitosan at the optimum

condition ........................................................................................................................ 129

Figure 4.28: SEM for un treated cotton sample ................................................................... 129

Figure 4.29: SEM cotton sample treated with chitosan ....................................................... 129

Figure 5.1: Effect of NaOH concentration on the K/S values of the chitosan printed PET

samples .......................................................................................................................... 135


chitosan printed 50% cotton – 50% PET samples ......................................................... 137

Figure 5.3: Means and standard errors for the effect of NaOH concentration on the K/S values

of the chitosan printed 65% cotton – 35% PET samples ............................................... 139

Figure 5.4: Means and standard errors for the comparison between NaOH concentration

effect on different chitosan printed fabrics .................................................................... 141

Figure 5.5: Means and standard error for the effect of fixation temperature on the K/S values

of the chitosan printed PET samples ............................................................................. 142

13






of the chitosan printed cotton samples .......................................................................... 148

Figure 5.9 Means and standard errors for the comparison between fixation temperatures

effect on different chitosan printed fabrics .................................................................... 149


chitosan printed PET samples ........................................................................................ 151






chitosan printed cotton samples ..................................................................................... 157

Figure 5.14: Means and standard errors for the comparison between fixation time effect on

the different fabrics ........................................................................................................ 158


values of the chitosan padded PET samples .................................................................. 160


chitosan printed 50% cotton- 50% PET samples ........................................................... 162


chitosan padded 65% cotton- 35% PET samples .......................................................... 164


chitosan printed cotton samples ..................................................................................... 165

Figure 5.19 Means and standard errors for the comparison between chitosan concentration

effects on different fabrics ............................................................................................. 167

Figure 5.20: SEM for un treated PET sample ...................................................................... 175

Figure 5.21: SEM for PET sample printed with chitosan .................................................... 175


Figure 5.23: SEM for 50% cotton – 50% PET sample printed with chitosan ..................... 176


Figure 5.25: SEM for 65% cotton – 35% PET sample printed with chitosan ..................... 177

Figure 5.26: SEM for un treated cotton sample ................................................................... 177

Figure 5.27: SEM for chitosan printed cotton sample ......................................................... 177

Figure 6.1: Discharge printing of PET samples and polyester/ cotton blends ...................... 181

Figure 6.2: Explanation diagram for the resist printing technique ....................................... 183

Figure 6.3: Means and standard error for the effect of fixation temperature on the percentage

decrease of K/S values of the resist printed PET samples ............................................. 185


decrease in K/S values of the resist printed 50 % cotton – 50 % PET samples ............ 187



14

Figure 6.6: Means and standard error for the effect of fixation time on the percentage

decrease in K/S values of the resist printed PET samples ............................................. 191





Figure 6.9: Means and standard error for the effect of NaOH concentration on the percentage

decrease in K/S values of the resist printed PET samples ............................................. 197

Figure 6.10: Means and standard error for the effect of NaOH concentration on the

percentage decrease in K/S values of the resist printed 50% cotton – 50% PET samples

........................................................................................................................................ 199


percentage decrease in K/S values of the resist printed 65% cotton – 35% PET samples

........................................................................................................................................ 201

Figure 6.12: SEM for chitosan printed PET sample ............................................................ 203

Figure 6.13: SEM for PET sample resist printed with sodium hydroxide ........................... 203

Figure 6.14: SEM for chitosan printed 50% cotton – 50% PET sample ............................. 203

Figure 6.15: SEM for 50% cotton – 50% PET sample resist printed with sodium hydroxide

........................................................................................................................................ 204

Figure 6.16: SEM for chitosan printed 65% cotton – 35% PET sample ............................. 204

Figure 6.17: SEM for 65% cotton – 35% PET sample resist printed with sodium hydroxide

........................................................................................................................................ 204

Figure 9.1: Plot of fitted model for the effect of chitosan concentration on the K/S values of

PET samples .................................................................................................................. 218


50% cotton - 50% PET samples .................................................................................... 219




cotton samples ............................................................................................................... 223

Figure 9.5: Plot of fitted model for the effect of chitosan fixation temperature on the K/S

values of PET samples ................................................................................................... 224


values of 50% cotton - 50% PET samples ..................................................................... 226


values of cotton samples ................................................................................................ 229

Figure 9.9: Plot of fitted model for the effect of chitosan fixation time on the K/S values of

PET samples .................................................................................................................. 231



Figure 9.13: Plot of fitted model for the effect of NaOH concentration on the K/S values of

PET samples .................................................................................................................. 237



15




PET samples .................................................................................................................. 243












PET samples .................................................................................................................. 254

Figure 10.10: Plot of fitted model for fixation time effect on K/S values of 65% Cotton - 35%

PET samples .................................................................................................................. 257

Figure 10.11: Plot of fitted model for fixation time effect on K/S values of Cotton samples

........................................................................................................................................ 258

Figure 10.12: Plot of fitted model for chitosan concentration effect on K/S values of PET

samples .......................................................................................................................... 260

Figure 10.13: Plot of fitted model for chitosan concentration effect on K/S values of 50 %

cotton - 50% PET samples ............................................................................................. 261

Figure 10.14: Plot of fitted model for chitosan concentration effect on K/S values of 65 %


Figure 10.15: Plot of fitted model for chitosan …………………………………….…… effect

on K/S values of cotton samples .................................................................................... 264

Figure 11.1: Plot of fitted model for the effect of chitosan fixation temperature on K/S values

of PET samples .............................................................................................................. 268


of 50 % cotton - 50% PET samples ............................................................................... 269



Figure 11.4: Plot of fitted model for the effect of chitosan fixation time on K/S values of PET

samples .......................................................................................................................... 272

Figure 11.5: Plot of fitted model for the effect of chitosan fixation time on K/S values of 50

% cotton - 50% PET samples ........................................................................................ 274


samples .......................................................................................................................... 277

16





17

List of tables

Table 4.1. Weight gain after chitosan printing of cotton, polyester, 50% cotton-50% polyester

blend and 65% cotton-35% polyester blend .................................................................. a90

Table 4.2: The K/S means values of PET samples treated with different NaOH concentrations

.......................................................................................................................................... 93

Table 4.3: K/S mean values of blend 1 samples treated with different NaOH concentrations

.......................................................................................................................................... 95

Table 4.4: the K/S mean values of 65% cotton- 35% PET samples for each NaOH

concentration. .................................................................................................................. 97

Table 4.5: The K/S means values of PET samples for each fixation temperature .................. 99

Table 4.6: The K/S mean values of blend 1 samples for each fixation temperature three

samples each .................................................................................................................. 101

Table 4.7: The K/S mean values of blend II samples for each fixation temperature ............ 103

Table 4.8: The mean values of K/S for cotton samples treated with different fixation

temperatures ................................................................................................................... 104

Table 4.9: The K/S mean values of PET samples for each set of fixation time ................... 106

Table 4.10: The K/S mean values of 50% cotton – 50% PET samples for each fixation time

for three samples ............................................................................................................ 108


........................................................................................................................................ 110

Table 4.12: The K/S means values of cotton samples for each fixation time ....................... 112

Table 4.13: The K/S mean values of PET samples for each chitosan concentration ............ 114

Table 4.14: The K/S mean values of 50% cotton- 50% PET samples for each chitosan

concentration ................................................................................................................. 116

Table 4.15: The K/S mean values of 65% Cotton- 35% PET samples for each chitosan

concentration ................................................................................................................. 117

Table 4.16: The K/S mean values of cotton samples for each chitosan concentration .......... 119

Table 4.17: Fastness to crocking properties of chitosan padded fabrics ............................... 122

Table 4.18: Fastness properties of chitosan padded fabrics for domestic and commercial

laundering ...................................................................................................................... 124

Table 4.19: Fastness properties of chitosan padded fabrics for perspiration ........................ 125

Table 5.1: The K/S mean values of PET samples for each NaOH concentration ................ 135

Table 5.2: The K/S means value for blend 1 samples of each NaOH concentration ............ 137

Table 5.3: The means of K/S values of blend 2 samples for each NaOH concentration . ..... 139

Table 5.4: The K/S means values of chitosan printed PET samples for each fixation

temperature .................................................................................................................... 142

Table 5.5: K/S mean values of chitosan printed blend 1 samples for each fixation temperature

........................................................................................................................................ 144

Table 5.6: K/S mean values of chitosan printed blend 2 samples for each fixation temperature

........................................................................................................................................ 146

Table 5.7: The mean values of K/S for cotton samples of each fixation temperature ........... 147

Table 5.8: The K/S means values of PET samples for each fixation time ............................ 150

18

Table 5.9: The K/S means values of 50% cotton – 50% PET samples for each fixation time

three samples each ......................................................................................................... 152


........................................................................................................................................ 154

Table 5.11: The K/S means values of cotton samples for each fixation time ....................... 156

Table 5.12: The K/S mean values of PET samples for each chitosan concentration ............ 160

Table 5.13: The mean values of K/S of 50% cotton- 50% PET samples for each chitosan ..

........................................................................................................................................ 161

Table 5.14 The K/S mean values of 65% cotton- 35% PET samples for each chitosan

concentration ................................................................................................................. 163

Table 5.15 The K/S mean values of cotton samples for each chitosan concentration .......... 165

Table 5.16: Fastness to dry and wet crocking of chitosan printed samples .......................... 168

Table 5.17: Fastness properties of chitosan printed fabrics for domestic and commercial

laundering ...................................................................................................................... 170

Table 5.18: fastness properties of chitosan printed fabrics for perspiration ......................... 171

Table 6.1: The percentage decrease in K/S means values of resist printed PET samples for

each fixation temperature .............................................................................................. 185

Table 6.2: The percentage decrease in K/S means values of resist printed 50 % cotton – 50 %

PET samples for each fixation temperature ................................................................... 187

Table 6.3: The percentage decrease in K/S mean values of resist printed 65 % cotton – 35 %

PET samples for each fixation temperature ................................................................... 189

Table 6.4: The percentage decrease in K/S mean values of resist printed PET samples for

each fixation time .......................................................................................................... 191


PET samples for each fixation time ............................................................................... 192


PET samples for each fixation time ............................................................................... 194


each NaOH concentration .............................................................................................. 197

Table 6.8: The percentage decrease in K/S mean values of resist printed 50% cotton – 50%

PET samples for each NaOH concentration .................................................................. 199

Table 6.9: The percentage decrease in K/S mean values of resist printed 65% cotton – 35%

PET samples for each NaOH concentration .................................................................. 201

Table 9.1: means and standard deviation for the effect of chitosan concentration on polyester

samples .......................................................................................................................... 217

Table 9.2: ANOVA Table for the effect of chitosan concentration on the K/S values of PET

samples .......................................................................................................................... 218

Table 9.3: LSD differences at 95% confidence level between each set of chitosan

concentration ................................................................................................................. 218

Table 9.4: means and standard deviation for the effect of chitosan concentration on 50%


Table 9.5: ANOVA Table for the effect of chitosan concentration on the K/S values of 50%


19


concentration ................................................................................................................. 220



Table 9.8: ANOVA Table for the effect of chitosan concentration on the K/S values of 65%



concentration ................................................................................................................. 222

Table 9.10: means and standard deviation for the effect of chitosan concentration on cotton

samples .......................................................................................................................... 222

Table 9.11: ANOVA Table for the effect of chitosan concentration on the K/S values of

cotton samples ............................................................................................................... 223


concentration ................................................................................................................. 223

Table 9.13: means and standard deviation for the effect of chitosan fixation temperature on

PET samples .................................................................................................................. 224

Table 9.14: ANOVA Table for the effect of chitosan fixation temperature on the K/S values

of PET samples .............................................................................................................. 225

Table 9.15: LSD differences at 95% confidence level between each set of chitosan fixation

temperature .................................................................................................................... 225




of 50% cotton - 50% PET samples ............................................................................... 226


temperature .................................................................................................................... 227




of 65% cotton - 35% PET samples ............................................................................... 228


temperature .................................................................................................................... 228


cotton samples ............................................................................................................... 229


of cotton samples ........................................................................................................... 230


temperature .................................................................................................................... 230

Table 9.25: means and standard deviation for the effect of chitosan fixation time on PET

samples .......................................................................................................................... 230

Table 9.26: ANOVA Table for the effect of chitosan fixation timee on the K/S values of PET

samples .......................................................................................................................... 231


time ................................................................................................................................ 231

20

Table 9.28: means and standard deviation for the effect of chitosan fixation time on 50%


Table 9.29: ANOVA Table for the effect of chitosan fixation timee on the K/S values of 50%



time ................................................................................................................................ 233



Table 9.32: ANOVA Table for the effect of chitosan fixation timee on the K/S values of 65%



time ................................................................................................................................ 234

Table 9.34: means and standard deviation for the effect of chitosan fixation time on cotton

samples .......................................................................................................................... 235

Table 9.35: ANOVA Table for the effect of chitosan fixation timee on the K/S values of

cotton samples .............................................................................................................. 236


time ................................................................................................................................ 236

Table 9.37: means and standard deviation for the effect of NaOH concentration on PET

samples .......................................................................................................................... 236

Table 9.38: ANOVA Table for the effect of NaOH concentration on the K/S values of PET

samples .......................................................................................................................... 237

Table 9.39: LSD differences at 95% confidence level between each set of NaOH

concentrations ................................................................................................................ 238

Table 9.40: means and standard deviation for the effect of NaOH concentration on 50%


Table 9.41: ANOVA Table for the effect of NaOH concentration on the K/S values of 50%



concentrations ................................................................................................................ 239






concentrations ................................................................................................................ 241


samples .......................................................................................................................... 242

Table 10.2: ANOVA Table for the effect of NaOH concentration on the K/S values of PET

samples .......................................................................................................................... 243


concentrations ................................................................................................................ 243



21




concentrations ................................................................................................................ 245






concentrations ................................................................................................................ 246


K/S values of PET samples ........................................................................................... 247


of PET samples .............................................................................................................. 248


temperature .................................................................................................................... 248


K/S values of 50% cotton - 50% PET samples ............................................................. 249


of 50% cotton - 50% PET samples ................................................................................ 250


temperature .................................................................................................................... 250


K/S values of 65% cotton - 35% PET samples ............................................................. 250


of 65% cotton - 35% PET samples ................................................................................ 251


temperature .................................................................................................................... 251


K/S values of cotton samples ......................................................................................... 252


of cotton samples ........................................................................................................... 253


temperature .................................................................................................................... 253

Table 10.22: means and standard deviation for the effect of chitosan fixation time on K/S


Table 10.23: ANOVA Table for the effect of chitosan fixation time on the K/S values of PET

samples .......................................................................................................................... 254


time ................................................................................................................................ 254



Table 10.26: ANOVA Table for the effect of chitosan fixation time on the K/S values of 50%


22


time ................................................................................................................................ 256



Table 10.29: ANOVA Table for the effect of chitosan fixation time on the K/S values of 50%



time ................................................................................................................................ 257



Table 10.32: ANOVA Table for the effect of chitosan fixation time on the K/S values of

cotton samples ............................................................................................................... 259


time ................................................................................................................................ 259

Table 10.34: means and standard deviation for the effect of chitosan concentration on K/S



PET samples .................................................................................................................. 260


concentrations ................................................................................................................ 260


values of 50 % cotton - 50% PET samples .................................................................... 261

Table 10.38: ANOVA Table for the effect of chitosan concentration on the K/S values of 50



concentrations ................................................................................................................ 262



Table 10.41: ANOVA Table for the effect of chitosan concentration on the K/S values of 65



concentrations ................................................................................................................ 263




cotton samples ............................................................................................................... 265


concentrations ................................................................................................................ 265


K/S values of PET samples ........................................................................................... 267


of PET samples .............................................................................................................. 268


temperature .................................................................................................................... 268

23


K/S values of 50 % cotton - 50% PET samples ............................................................ 269




temperature .................................................................................................................... 270


K/S values of 65 % cotton - 35% PET samples ............................................................ 270




temperature .................................................................................................................... 271




samples .......................................................................................................................... 273


time ................................................................................................................................ 273



Table 11.14: ANOVA Table for the effect of chitosan fixation time on the K/S values of 50



time ................................................................................................................................ 274






time ................................................................................................................................ 276




samples .......................................................................................................................... 277


concentrations ................................................................................................................ 277






concentrations ................................................................................................................ 279



24




concentrations ................................................................................................................ 281

25

Abstract

This research investigated the possibility of improving the dyeability of fabrics made from

polyester and cotton by using chitosan surface treatments. A pad-cure-dye process was used

as this avoids using harmful chemicals and is cost effective.

The work was extended to study the application of chitosan on poly/cotton blended fabrics to

improve their dyeability and printability. The chitosan treatment used was a pad-cure-dye

process that enabled the dyeing of blended fabrics using one dye bath containing

commercially available acid dyes.

The research findings showed that it was possible to use a chitosan surface treatment to

improve the dyeability of polyester, cotton and poly/cotton blended fabrics using a single dye

bath technique in a cost effective and eco-friendly way.

After investigating the possibility of applying chitosan to improve the dyeability of the

studied fabrics, the work was extended to study the use of chitosan in the differential printing

of polyester, cotton and two sets of poly/cotton blends.

This was achieved by applying chitosan as a non-coloured paste to the fabrics. It was found

that areas treated with chitosan attracted more dyestuff than the rest of the untreated fabric.

Using this technique, a printed design of two shades was obtained using a single dye bath.

This technique would be useful when designing multi-shaded fabrics using one colour. This

also enables clothing and textile factories to quickly respond to market changes in one

season, i.e. a stock of printed textiles with clear chitosan could be prepared and stored to be

dyed with the required colour when stock is running low.

After demonstrating the possibility of dyeing polyester and poly/cotton blends with acid dyes,

the research studied the possibility of resist printing polyester and poly/cotton blended fabrics

using chitosan using commercially available acid dyes.

The findings provided great results indicating the possibility of resist printing polyester and

poly/cotton fabrics without the need of applying specially synthesized dyes or hazardous

chemicals.

26

Declaration

I certify that no portion of the work referred to in the thesis has been submitted in support of

an application for another degree or qualification of this or any other university or other

institute of learning.

27

Copyright Statement

i. The author of this thesis (including any appendices and/or schedules to this thesis) owns

certain copyright or related rights in it (the “Copyright”) and s/he has given The University of

Manchester certain rights to use such Copyright, including for administrative purposes.

ii. Copies of this thesis, either in full or in extracts and whether in hard or electronic copy,

may be made only in accordance with the Copyright, Designs and Patents Act 1988 (as

amended) and regulations issued under it or, where appropriate, in accordance with licensing

agreements which the University has from time to time. This page must form part of any such

copies made.

iii. The ownership of certain Copyright, patents, designs, trademarks and other intellectual

property (the “Intellectual Property”) and any reproductions of copyright works in the thesis,

for example graphs and tables (“Reproductions”), which may be described in this thesis, may

not be owned by the author and may be owned by third parties. Such Intellectual Property

and Reproductions cannot and must not be made available for use without the prior written

permission of the owner(s) of the relevant Intellectual Property and/or Reproductions.

iv. Further information on the conditions under which disclosure, publication and

commercialisation of this thesis, the Copyright and any Intellectual Property and/or

Reproductions described in it may take place is available in the University IP Policy (see

http://documents.manchester.ac.uk/DocuInfo.aspx?DocID=487), in any relevant Thesis

restriction declarations deposited in the University Library, The University Library’s

regulations (see http://www.manchester.ac.uk/library/aboutus/regulations) and in The

University’s policy on Presentation of Theses.

28

Acknowledgments

Love and praise be to God for helping and giving me the power and effort to complete this

work.

I would like to express my heartfelt gratitude to my supervisors Dr Huw Owens, and Prof.

Franz J Wortmann for their wide knowledge and logical way of thinking which have been of

a great value for me. Their understanding and guidance have provided a good basis for the

present study.

I would like to thank my sponsors, the Egyptian Ministry of Higher Education, the Egyptian

Cultural Bureau and the Missions Department in Egypt.

I would like to thank all the staff and colleagues at the University of Manchester for all the

help and assistance provided; you have made it an enjoyable journey for me.

I would like to thank my family who instilled within me a love of creative pursuits and thirst

for knowledge.

I would like to thank my husband for all the support and help he offered me, and for being

such a great partner, to all of them, thank you.

29

1. Chapter One: Introduction

This thesis discusses the possibility of using chitosan surface treatments to improve the

dyeability/printability of polyester and poly/cotton textile fabrics. The research is divided into

three parts.

The first part studies the use of chitosan treatments to improve the dyeability of polyester and

poly/cotton fabrics. It also investigates the use of commercially available acid dyes in the

dyeing of polyester, cotton, and their blends in an eco-friendly way.

A novel approach was investigated in the second part; which studies the creation of a new

technique for textile printing (differential printing). This technique relies on printing chitosan

on polyester, cotton, and poly/cotton blends and then dyeing them later. This technique

creates a two shaded design i.e. the chitosan print will attract more dye stuff than the rest of

the fabric making a two coloured shaded fabric at the same time whilst using only one single

bath.

The third part discusses the possibility of applying chitosan in order to resist print a

hydrophobic material, such as polyester, in an eco-friendly and cost effective way.

1.1. Aim of work

The textile industry generates a huge amount of dyes and axillaries every year, which

represents a great challenge on the environment. In addition the cost of using these chemicals

and the cost of removing them from the waste water afterwards inevitably affects the end

price of the product.

The United Kingdom textiles market grew by 6.3% in 2010 to reach a value of 33.5 billion

dollars. Apparel is the largest segment of the textiles market in the United Kingdom,

accounting for 36.7% of the market's total value (Datamonitor, 2011).

The manufacturing process to create a textile product may take a significant time from

designing the product, to producing a finished product on the shelves in the stores.

For the above reasons, the aims of this work include:

Finding a method that enables a swift response to market changes and fashion

changes during the same season.

Improving the dyeability and printability of several textile materials without the need

for traditional axillaries in the colouration process in a more economically and

ecofriendly method.

30

Using chitosan to enable polyester dyeing with commercially available acid dyes.

Using the padding process to improve the dyeability of cotton, polyester, and

cotton/polyester blends.

Using chitosan to produce differential printings on different textile materials.

Using chitosan to produce resist prints on PET fabric and its blends.

1.2. Thesis layout

1. Chapter one provides the introduction section which introduces an overview of the

work and the aims and objectives of this work

2. Chapter two is a review of the relevant literature in the area of investigation. It also

includes discussions of the existing body of work concerned with the application of

chitosan application methods in the textile industry and its use in improving the

physical and mechanical properties of textiles.

3. Chapter three provides an overview of the methodology used in this research.

4. Chapter four covers the using of the padding process to improve the dyeability of

cotton, polyester, and cotton/polyester blends. The experimental research conducted,

results and statistical analysis are also mentioned.

5. Chapter five covers the results and the statistical analysis for the differential printing of

cotton, polyester, and cotton/polyester blends with chitosan.

6. Chapter six explains a novel approach in resist printing polyester and polyester/cotton

blended fabrics. It also covers the results and the statistical analysis for using chitosan

in the resist printing of polyester and its blends.

7. Chapter seven presents the conclusions and the recommendations for further

investigation and future work.

31

2. Chapter Two: Literature review

2.1. Textiles

Textile fabrication is a very old craft recorded in myths and ancient stories. Textiles have

always been important to man, textiles were used as protection from the elements and for

decoration, they were also used as bags for transporting belongings and for gathering food

(Wilson, 2001).

A textile fibre is a long thin object with a high length to thickness ratio, and with a high

degree of flexibility. In addition it should be stable and has an acceptable level of strength,

and can be converted into yarns and fabrics (Gupta and Kothari, 1997).

2.2. Classification of fibres

Textile fibres are the basic element of fabrics and other textile structures (Houck, 2009).

Textile fibres can be classified as natural fibres and manufactured fibres. As this research will

study improving the printability of natural fibres i.e. cotton and manufactured fibres i.e.

polyester and their blends, a brief discussion of their properties is mentioned below.

2.2.1. Natural fibres

Natural fibres are made from plants (i.e. cotton, flax), animal (i.e. wool, silk) or mineral

origin or occur in nature (i.e. asbestos).

2.2.1.1. Cotton

Cotton is mainly cellulose, nearly 90% of cotton fibres is cellulose. The cellulose in cotton

fibres is of a high molecular weight and high crystallinity. This is why cotton is considered

the most versatile fibrous material of all (Gordon and Hsieh, 2006).

Cellulose as shown in figure 2.1 is a high molecular weight polysaccharide polymer that

consists of long chains of glucose units connected by b-1, 4; every glucose unit contains three

hydroxyl groups (Iqbal, 2008).

Figure 2.1: Chemical structure of cellulose (Iqbal, 2008)

32

The repeat unit of cellulose is Cellobiose which is made of two glucopyranose units. It is very

hard to precisely determine the degree of polymerisation (DP) of cotton, this is because of the

variation of cotton sources (Maher and Wardman, 2015).

A cotton fibre looks like a flat twisted ribbon that consists of one single cell closed from one

end and open from the other end where it was cut from the seed as shown in figure 2.2.

Figure 2.2: Scanning electron micrographs of raw cotton fibres (Maher and Wardman,

2015)

Glucose chains in cellulose connect together with hydrogen bonds between the hydroxyl

groups, this crystalline form gives cellulose the ability to absorb water without dissolving in

it. When wetted, the hydroxyl groups in cotton glucose chains form hydrogen bonds with

water (Broadbent et al., 2001).

2.2.1.2. Chemical properties of cotton

Dehydration

The immature cotton fibre is fully hydrated, and is in a cylindrical shape. When matured,

cotton fibres loose fluids, which causes the cylindrical shape of the fibres to collapse and

forms twists. Losing the intermolecular water within the fibre allows the cellulose chains to

get closer and form intermolecular hydrogen bonds. This effect is not reversible and changes

the fibre morphology forever (Hsieh, 2007).

33

Reaction with acids

Acids have a devastating effect on cotton. When treated with acids, cellulose polymer chain

splits in a hydrolysis reaction as explained next in figure 2.3.

Figure 2.3: Cotton reaction with acids (Maher and Wardman, 2015)

The polymer chain in cellulose immediately splits when treated with acids. This also means a

decrease of the degree of polymerization and tensile strength of cotton fibres (Maher and

Wardman, 2015).

Reaction with alkali

Alkalis can also affect cotton fibres, especially in high temperature. It can cause hydrolysis of

cellulose, which happens stepwise by the removal of the ends of the cellulose chains. That

mentioned, the most important effect of alkaline on cellulose is swelling. Known as

mercerisation, when cotton fibres are treated with alkaline solution, the diameter of the fibre

swells and the fibre shrinks. This effect is usually done to increase the dyeability and density

of the fibre (Maher and Wardman, 2015).

34

Oxidation

When cotton is treated with oxidising agents, the glucosidic repeating units start to oxidise.

Few reactions occur at this stage, the repeating glucosidic groups oxidises into an aldehyde

and then to a carboxylic acid. Also the glucosidic ring breaks between C-2 and C-3 and

between C-1 and the oxygen atom of the ring. The results of the oxidation of cotton are

shown in figure 2.4 (Maher and Wardman, 2015).

Figure 2.4: Oxidation of cotton (Maher and Wardman, 2015)

Effect of heat on cotton fibres

Cotton fibres are stable in temperature up to 150 °C, by increasing the temperature above 150

°C combined with moisture and atmospheric oxygen the glucosidic linkages break, leading to

the formation of hydrocelluloses and the reduction in the tensile strength of the cotton fibres.

This also means cotton turns yellow because the formation of aldehyde and carboxylic acid

groups. By increasing the temperature to 200 °C cotton fibres completely lose their tensile

strength (Maher and Wardman, 2015).

Reactivity of cotton fibres

Cotton reactivity is mainly because of the three hydroxyl groups present in the glucosidic

ring. They give cotton fibres the ability of attracting water and moisture because of the

hydrophilic nature of those hydroxyl groups. This is why these hydroxyl groups are usually

35

targeted in reactions to improve the dyeing and finishing ability of cotton. The primary

hydroxyl group has higher reactivity than the two secondary hydroxyl groups, and the

reactivity of those two hydroxyl groups is mainly dependant on the chemical compound they

are reacting with. In the application of reactive dyes, the main hydroxyl group in the

glucosidic ring of cotton is the group that react with the reactive dye (Maher and Wardman,

2015).

2.2.2. Manufactured fibres

Manufactured fibres are fibres produced from fibre-forming polymers which may be:

1. Modified or transformed natural polymers, i.e. rayon viscose;

2. Synthesised polymers, i.e. polyester and polyamide (Gupta and Kothari,

1997).

2.2.2.1. Polyester

Being the most popular synthetic fibre, polyester has been around for more than fifty years.

Despite having a number of drawbacks, it became the world’s bestselling synthetic fibre

because of its low cost and good properties. Nowadays many attempts have been made to

modify the fibre to overcome its drawbacks (Edwards et al., 2006).

Polyester also known as PET, with scientific name Poly(ethylene terephthalate), was first

discovered in 1941 in Accrington, UK laboratories of the Calico Printers Association

(Edwards et al., 2006).

PET is a linear homopolymer, produced by the polymerisation of terephthalic acid and

ethylene glycol (Edwards et al., 2006; Iqbal, 2008) .

Figure 2.5: Chemical structure of PET (Edwards et al.; 2006, Iqbal, 2008)

Polyester as shown in figure 2.5 is defined by the International Standards Organisation (ISO)

as a polymer comprising synthetic linear macromolecules having in the chain at least 85% of

an ester of a diol and terephthalic acid (Carothers, 1929; Gupta and Kothari, 1997; Houck,

2009).

n

36

2.2.2.2. Production of polyester

Polyester is produced by the reaction of terephthalic acid and ethylene glycol in the reaction

shown in figure 2.6 (Maher and Wardman, 2015).

Figure 2.6: Syntheses of polyethylene terephthalate (Maher and Wardman, 2015)

2.2.2.3. Chemical properties of polyester

Polyester is resistant to acids, except strong acids at high temperature but is more affected by

alkaline. Polyester is resistant to many solvents but dissolves in 3-methyl phenol,

trifluoroethanoic acid and 2-chlorophenol.

Hydrolysis

Polyester can be hydrolysed by acids and alkalis. When treated with either acids or alkalis

polyester depolymerises back to the building component of the polymer. This hydrolysis is

mainly dependant on the rate of diffusion of the acid or alkali into the fibre. In the case of

sodium hydroxide treatment of polyester, the rate of diffusion is slow and only the surface of

the fibre is affected (Maher and Wardman, 2015).

The hydrolysis process of polyester is essential to impart hydrophilic properties to the

polyester and make it possible to dye it with other dyes rather than disperse dyes. This

process has been widely studied especially alkaline hydrolyses of polyester with Sodium

hydroxide (Dave et al., 1987).

Alkaline hydrolysis of PET is usually carried out with the use of an aqueous alkaline solution

such as NaOH as shown in figure 2.7 (Al-Sabagh et al., 2016).

37

Figure 2.7: Alkaline hydrolysis of PET (Al-Sabagh et al., 2016)

Thermal and photo degradation

Polyester starts to degrade at 260°C, it degrades quite slowly in the absence of oxygen below

the melting point, but degrades quite rapidly above 300°C. Polyester possess a high resistance

to photodegradation by sunlight compared to other synthetic fibres (Maher and Wardman,

2015).

Of all the synthetic fibres, PET is one with the most compact and crystalline structures (Fité,

1995). Polyester is one of the most popular manmade fibres because polyester has excellent

properties such as (Wang et al., 2012) :

Dimensional stability;

wrinkle resistance;

chemical resistance;

quick-drying properties;

moderate biocompatibility;

the ability to blend with other natural fibres such as cotton and wool.

However, polyester exhibits some drawbacks such as (Wang et al., 2012):

High crystallinity;

low moisture regain;

low level of comfort;

static electricity problems due to its hydrophobic nature;

it also has no functional groups when compared with natural fibres, so it cannot

interact with anionic or cationic dyes (Ibrahim et al., 2013a; Raffaele-Addamo et al.,

2006).

2.2.2.4. Polyester surface treatments

Polymeric materials are used in various fields, so it is important to obtain a polymer that can

adhere or react with other substrates. Being a hydrophobic polymer, polyester is not able to

38

adhere to other materials so surface modification is required to promote its adhesion to other

materials (Sophonvachiraporn et al., 2011).

There are two approaches to polymer surface modification: physical modification and

chemical modification. The physical modification is the modification of the polymer’s

surface physically, such as blending with other polymers; while the chemical modification

relies on changing the chemical structure of the polymer surface by a chemical reaction, such

as grafting and crosslinking. In the polymer-based textile industry, chemical modification

processes have been preferably used (Sophonvachiraporn et al., 2011).

Several modification methods are used to modify the surface of polymeric materials such as

polyester. One of the most popular methods is the immersion in an aqueous alkaline solution

such as NaOH which is known as the alkaline hydrolysis of PET (Al-Sabagh et al., 2016).

Strong acid solution also could be used to modify the surface of polymeric materials such as

polyester, but using such strong chemicals has its drawbacks such as the need for complicated

technologies to control the reaction, also this modification requires the use of unfriendly

harsh chemicals which is not desirable (Popelka et al., 2012).

There is a high demand in the market for producing highly functional value added textiles.

Because of this, more and more researchers are focusing on adding functionality and

hydrophilicity properties to synthetic fibres such as polyester. This is usually done by the

treatment of the synthetic fibres with a high functional substrate such as chitosan (Abdel-

Halim et al., 2010).

Chitosan has a high surface area which cause it to be highly active substrate that has a high

ability to react with textile fabrics (Ali et al., 2011). The application of chitosan to the surface

of textile fabrics to improve their qualities is heavily studied on natural fabrics especially

cotton, but there is lack of research in the application of chitosan to synthetic fabrics (Joshi et

al., 2009).

2.3. Colouration

2.3.1. What is colour and how do we see it?

Colour vision starts when the back of the eyeball (the retina) absorbs light, transmits it

through nerve impulses, and the brain interprets it as a colour. Basically what determine the

colour of an object is that when this object is subjected to light, it selectively absorbs part of

39

this light and reflects the remaining light into the observer’s eye. This is what is interpreted as

colour, which depends mainly on three factors: the eye of the person, the light, and the object.

Describing colour is usually done by the use of expressions like hue, saturation and lightness.

Hue is the actual colour (red, yellow, blue), saturation is how this colour differentiates from

grey i.e. dull or vivid, and lightness is the amount of light reflected in this colour i.e. light or

dark (Broadbent et al., 2001).

2.3.2. Colour measurements

Colour measurement is a numerical description of a colour. It is an essential tool in textile

dyeing. It is used for colour matching samples and determining the colour difference between

samples. Textile fabrics vary in texture and colour which would definitely affect the colour

measurements of a dyed textile fabric. Therefore, to measure the colour of a production,

several samples are taken from different parts of the batch and several readings are taken of

each sample. This way an average reading could be taken to make sure that nothing affected

this reading like an unlevelled dyeing. It is also important to make sure that the sample is

dense enough that no light transmits through the sample and reflects back from the surface of

the sample holder.

The colour measurement tool is called reflectance spectrophotometer. In most reflectance

spectrophotometers the colour is measured by measuring the light reflecting off the sample at

different wavelengths. There are many different types of spectrophotometer which may have

continuous or pulsed light sources, and different angles for the beams which could be double

or single beam.

As shown in figure 2.8 in a double beam reflection spectrophotometers which feature an

integrating sphere, the interior wall of the sphere is coated with a highly reflecting white

paint. When measuring a sample, the sample gets placed against a small opening in the

sphere. A light source beams a white light into the sphere, which reflects on the reflective

wall of the sphere onto the sample. The reflected light of the sample falls onto a diffraction

grating which disperses it into a detector to measure it at different wavelengths (Broadbent et

al., 2001).

40

Figure 2.8: A double beam reflection spectrophotometers (Broadbent et al., 2001)

2.4. Textile colouration

Textile colouration involves dyeing or printing of textile materials, as dyeing and printing

processes are being studied in this research, a brief description of them is detailed below.

2.4.1. Textile dyeing

The objective of dyeing is to colour the entire material so that the dye has completely

penetrated into the fibres and the surface has a completely uniform colour (Broadbent et al.,

2001).

Dyeing is a two-step process; the first step involves the attraction of dye particles from the

dyeing solution or the print paste to the substrate surface. The second step is the diffusion of

the dye particles within the substrate from one point to another, while printing is to

selectively colour selected areas (Ingamells, 1993).

Ancient Egyptians had coloured fabrics as early as 2500 B.C., this is likely to be the source of

the process that spread to the rest of the world. Colouring materials were originally extracted

from plants (roots, leaves, fruits, flowers, and seeds) and from animals (insects and shellfish)

and this practice continued until the nineteenth century (Dawson and Hawkyard, 2000).

2.4.2. Textile printing

Textile printing is an ancient art which started way back in time. Evidence of the existence of

textile printing has been excavated in Upper Egypt. As a proof of the use of printed textiles,

excavation has unearthed fragments of printed garments along with curved wooden blocks

used in the printing process. In the 18th

century the textile printing industry started to revive

41

specially in Lancashire, UK, by the use of hand block printing from about 1760, and

engraved copper roller printing in 1790 (Dawson and Hawkyard, 2000).

The textile industry and especially textile printing grew rapidly in Lancashire, UK, from 1790

until the First World War. After that, the industry had a recession until after the Second

World War. In this period advanced technologies broke out like screen printing and the

invention of new materials like polyester and new dyes like reactive and disperse dyes. In this

period the textile printing process changed from an expensive art to a scientific and

technologically calculated process (Dawson and Hawkyard, 2000).

2.4.2.1. Textile printing styles

Direct printing

Printing is localised dyeing; printed fabrics could be produced by the same technique used to

produce plain dyed fabrics using the same dye fixation mechanism (Miles and Leslie, 2010).

Today the most widely used colorant in textile direct printing is pigment, that is because it is

a simple and low cost technique and it does not require a lot of equipment (Dawson and

Hawkyard, 2000), as shown in table 2.1.

Table 2.1. Market shares between pigments and reactive dyes (Dawson and Hawkyard,

2000)

Market share (%)

Market area Pigment Reactive

North America 80 20

South America 65 35

Europe 50 50

Mid/Far East 33 67

World wide 64 36

Discharge printing

Discharge printing is when a fabric is dyed with a solid colour dye that could be discharged

later by printing a chemical that can destroy the dye in the printed area during steaming. This

42

would form a white design and a coloured ground. Some techniques use a paste containing

dyes that are resistant to the discharging chemicals in the printing paste. This would result in

colouring the discharged area which called coloured discharge (Clarke, 2013; Broadbent et

al., 2001).

Resist printing

Resist printing is used to prevent the dye absorption on the fabric, this is done by blocking the

fabric from dye penetration or fixation. This process is done by printing the resist agent and

then dyeing the fabric, the result would be a white design on a coloured fabric (Ingamells,

1993; Broadbent et al., 2001).

2.5. Textile colourants

2.5.1. Pigments

Since 1960 pigments have been the largest colorant group for textile prints and form more

than 50% of the textile printing production. Pigments are insoluble colourants which means

they have no affinity to fibres and are usually fixed on textile materials using binders. This

explains why pigments are not considered to be dyes. Pigments are so widely used because of

the cost efficiency and simplicity (Miles and Leslie, 2010).

The quality of printed textiles depends on three factors: the type of binder used, the pigment

dispersion and the thickener used to give the printing paste the required rheology (Miles and

Leslie, 2010).

2.5.2. Textile dyes

Since the beginning of the textile industry there have been dyes driven from natural sources

to be used as dyes for fabrics. In modern times the most important discovery in textile

colouration history is the invention of synthetic dyes in 1856. Since then thousands of dyes

have been made (Broadbent et al., 2001).

2.5.2.1. Acid dyes

Acids dyes also known as mordant dyes are usually used to dye protienic fibres and

polyamides. The name acid dyes is derived from the used of strong acid in the dye path. Acid

dyes are usually sodium salts of sulfonic acids or carboxylic acids, they anionise in aqueous

solutions. That is why acid dyes are suitable for dyeing substrates with cationic sites such as

wool, silk and nylon. When these fibres absorb the acid, the acid protonates the amino groups

43

in the fibre making it cationic, this in return facilitates the bonding between the cationic fibre

and the anionised dye in the dye path as explained in figure 2.9 (Broadbent et al., 2001).

Acid dyes’ molecular weight ranges between 300 and 1000 g/mol some dyes have larger

molecules with a slower diffusion in the fibre and less levelness. Acid dyes are available as

powder, grains, liquids, and in fine dispersions for the less soluble types (Broadbent et al.,

2001).

Figure 2.9: Reaction between a cationic fibre and the acid dye (Broadbent et al., 2001)

2.5.2.2. Acid dyes classification

There are different classifications for acid dyes; one of them is according to their chemical

structure. In this classification acid dyes are divided into azo; anthraquinone;

triphenylmethane; pyrazolone; azine; nitro; and quinoline. The most used group of acid dyes

is azo dyes followed by anthraquinone (Iqbal, 2008).

Acid dyes are classified into four categories according to their dyeing characteristics:

level dyeing or equalising dyes;

fast acid dyes;

milling acid dyes;

super-milling acid dyes.

Levelling acid dyes

Levelling acid dyes are acid dyes that have a high levelness and brighter colours than other

acid dyes. It requires the use of strong acids to achieve good exhaustion. They also have high

migration ability which probably is the reason that these dyes have poor washing and light

fastness. Levelling acid dyes are most importantly water soluble dyes because of the

relatively small molecular size, this gives them the ability to penetrate twisted yarns and

tightly woven fabrics (Clark, 2011).

Fast acid dyes

These dyes are usually monosulfonated dyes, they have higher molecular weight than

levelling acid dyes, they are usually used when levelled dyeing is required with good washing

and perspiration fastness (Clark, 2011).

44

Milling acid dyes

Milling acid dyes are dyes that have good fastness to milling: weak alkaline treatment of

wool to produce a felting effect. Milling dyes have higher molecular weight than levelling

and fast acid dyes, they also have fewer sulfonate groups and that is why they also have lower

water solubility. Milling dyes tend to collide together even in boiling water. Milling acid dyes

give good washing fastness because of their poor migration properties. The dye bath starts by

gradually increasing the temperature and then lowering the pH by adding acetic acid

gradually (Clark, 2011).

Super-milling acid dyes

Super milling acid dyes are similar to milling dyes but more hydrophobic due to having long

chain alkyl groups. They have very good light fastness and good washing fastness. Super

milling and milling acid dyes have very rapid absorption and they do not have good

migration causing unlevelled dyeing, that is why they are mainly used for dyeing yarns

before weaving when they will be subjected to milling later. Like milling dyes, the super

milling dye bath starts by gradually increasing the temperature, then gradually lowering the

pH (Clark, 2011).

2.5.2.3. Dyeing process of acid dyes

Acid dyeing is very difficult to perform as it is influenced by several parameters:

Dyestuff selection

The selection of a dye depends on several factors i.e. the end use of the fabric to be dyed and

the required properties i.e. washing fastness in the case of wearable garments or light fastness

in the case of furnishing or automobile trimming. In some cases the selection of dyes used

would also be affected by the count and the twist of the yarn (Iqbal, 2008).

The dyeing pH

One of the most important factors in the acid dyeing process is the pH. That is because low

pH of 3 to 3.5 activates the NH2 groups allowing them to react with the ionised dye particles

resulting in rapid exhaustion of the dye (Iqbal, 2008).

The dyeing temperature

In acid dyes the dye path temperature should be close to the boiling temperature. Higher

temperatures result in better dyeing, levelling, and migration properties. The rate of

temperature increase is also very important in the dye exhaustion, some dyes start exhaustion

at 25-35° C, others start at 50-65° C, so it is really important to know the dyeing temperature

and the rate of temperature increase when dyeing with acid dyes (Iqbal, 2008).

45

The dyeing time

Dyeing time is a really an important factor in the dyeing process. It is also considered a cost

efficient factor that affects the final cost of the dyed fabric. A common practice is to get a

sample at the time of 40-45 minutes after boiling, if the result is satisfactory then the dyeing

process should be stopped, if not the dyeing process should continue for 10-20 minutes more

(Iqbal, 2008).

Type and quantity of auxiliaries

Some acid dyes require the use of auxiliaries to assist the dyeing process. Mainly they are

used to increase the levelling properties of the dye. This is done by slowing down the

exhaustion process, thus achieving levelness. In nylon dyeing, anionic auxiliaries are used in

the dye bath to block the dye active site temporarily hence slowing down the dye exhaustion

and forming a levelled dyed fabric. (Iqbal, 2008)

Nonionic auxiliaries have affinity to both the fabric and the dye; they block the active sites in

the fabric while forming a complex with the dye which slows down the exhaustion giving

levelled dyeing (Iqbal, 2008).

2.5.3. Colouring polyester

Polyester fibres are very popular synthetic fibres with a global market value of 18 million

dollars in year 2000. The popularity of polyester is due to the fact it is a cheap, easy to make,

strong, lightweight fibre, it also has an excellent wrinkle resistance, and good wash and wear

properties (Abdel-Halim et al., 2010).

Other sub products of polyester are also used widely in the carpet industry and in medical

fields. It is reasonable to think that the production of polyester will only increase in the future

(Abdel-Halim et al., 2010).

Recently there is special attention being paid to the surface treatment of polyester in order to

improve its dye uptake. One of these surface treatment is chitosan treatment, as chitosan is

widely used due to its polyamine character, biocompatibility, biodegradability, non-toxicity

and availability (Ibrahim et al., 2013a; Choudhury, 2006).

2.6. Chitosan

Chitosan which consists mainly of chitin [poly-(1-4)-N-acetyl-d-glucosamine] is one of the

most important natural polysaccharides. Its global production is estimated to be

approximately 5.118×106 tonnes annually (Anand et al., 2006).

46

Chitin is the main component in the shells of crustaceans such as shrimps, crabs, and lobsters

figure 2.10. It can be extracted also from some insects’ exoskeletons and from the cell wall of

some fungus (Navard, 2013; Rinaudo, 2006).

Figure 2.10: Crustacean sources of chitin

Chitin could be easily obtained from crab or shrimp shells by the removal of proteins and the

dissolution of calcium carbonate which is present in crab shells in high concentrations. The

resulting chitin is then deacetylated (- CH3COONa) in 40% sodium hydroxide at 1208 o C for

1–3 hours. This process produces 70% deacetylated chitosan, this reaction is illustrated in

figure 2.11 (Ravi Kumar, 2000).

Figure 2.11: The deacetylation of chitin (Ravi Kumar, 2000)

The chemical structure of chitin is similar to that of cellulose in many aspects, with the

exception of an acetamide group attached to the C-2 position instead of the hydroxyl group in

the case of cellulose. It is possible to obtain chitosan (which is the most important chitin

derivative) by partial deacetylation of chitin with alkali.

Chitosan is a linear polysaccharide built of β-(1-4)-2-aminodeoxy- d-glucopyranose units

and its idealised structure is similar to that of cellulose, as shown in figure. 2.12.

47

Figure 2.12: Chemical structure of chitosan

Chitosan is soluble contrarily to chitin which is not soluble; it is usually produced by grinding

crustaceans’ shells, washing the powdered shells in alkali and acid to remove the proteins and

minerals residues, and eventually deacetylation, which is treating with sodium hydroxide at

raised temperature (Anand et al., 2006; Singla and Chawla, 2001).

Chitin is insoluble in most organic solvents; on the contrary chitosan is soluble in acidic

solutions below pH 6.0. This is mainly because of the presence of the amino groups which

means that the pH change could substantially alter the charged state and properties of

chitosan (Yi et al., 2005).

At low pH, the amine groups get protonated and become positively charged and that makes

chitosan water-soluble (Pillai et al., 2009). This reaction is illustrated in figure 2.13.

Figure 2.13: Chitosan dissolution in acetic acid (Zhang et al., 2015)

It has been established by a number of researchers that chitosan has desirable properties such

as biodegradability, biocompatibility, antimicrobial activity, and nontoxicity source.

Therefore chitosan is used in several fields such as pharmaceutical and medical applications,

paper production, wastewater treatment, biotechnology, cosmetics, food processing and in the

agriculture industry as well (Hudson and Smith, 1998).

48

Chitosan is used to enhance the properties of several materials used within the textile industry

(Anand et al., 2006). It has been reported that chitosan could be used in textile finishes to

improve fabric dyeability and to add antimicrobial properties for textiles (Alonso et al., 2009;

Dev et al., 2009; Jocic et al., 2005; Lim and Hudson, 2004b; Abdel-Halim et al., 2010).

Although there is a significant volume of literature on the use of chitosan in antimicrobial

textiles, where chitosan has been used for coating or finishing (Joshi et al., 2009), there has

been no systematic research carried out on the characterisation and the application of chitosan

on polyester substrates to provide enhanced colouration properties (Ali et al., 2011).

2.6.1. The use of chitosan in colouration of different textile materials

2.6.1.1. Colouration of polyester with chitosan

Polyester fibres are hydrophobic and swell in water to a very small extent, which means that

polyester fibres have a fair affinity for dyestuff molecules. Also the lack of active groups on

the fabric surface contributes to the dyeing behaviour of polyester. It makes it impossible to

apply most dyestuffs apart from disperse dyes. Disperse dyes are dyes which are essentially

insoluble in water. They do however possess affinity for hydrophobic fibres such as

polyester, in which they are quite soluble (Iqbal, 2008).

The process of dyeing polyester fibres with disperse dyes is temperature dependent. As the

temperature rises, a small amount of the dye dissolves in water. Thermal motion of polymer

segments in the amorphous regions at temperatures above Tg allows dye molecules to

migrate inside the fibre, then when the temperature drops the dye molecules become trapped

inside the fibre (Broadbent et al., 2001).

Disperse dyeing is a chemical and energy rich process; environmental concerns and finding

solutions for the difficulties facing the industry in this field draw more attention to improving

the dyeability of synthetic fabrics (Broadbent et al., 2001).

In order to dye polyester in dark shades, auxiliaries and other synthetic chemicals are used in

the dye bath. These auxiliaries can be harmful to human skin and to the environment. They

may also reduce colour fastness to light (Walawska et al., 2003).

Natural polymers such as chitosan have many valuable properties such as biodegradability,

low toxicity, and thickening power, thus there is an increased attention to natural polymers

(Manyukova and Safonov, 2009).

49

Lately there have been intensive studies in the field of chitosan application in the textile

industry. It has been found that chitosan could be used as a dye fixing agent to improve the

fastness properties (Chattopadhyaya and Inamdarb, 2013).

Chitosan can easily absorb anionic dyes such as direct, acid, and reactive dyes by electrostatic

attraction due to its cationic nature in an acidic condition (Zhang and Zhang, 2010). The

modification of the fabric surface and the introduction of free amino groups of chitosan onto

the treated fabrics increase the cationicity of the surface, hence enhancing the electrostatic

attraction between the negatively charged groups of dye molecules and protonated amino

groups of the pretreated substrates and/or changing the hydrophobicity/hydrophilicity ratio

due to crosslinking, a phenomenon that increases the affinity for disperse dyes (Ibrahim et al.,

2013a; Ali et al., 2011).

In this study it is intended to investigate the use of chitosan to improve textile dyeability and

printability.

2.6.1.2. Coloration of cotton fabrics with chitosan

Cotton is a natural cellulosic fibre. It builds up negative charges on its surface when

immersed in water, resulting in an inverse effect on exhaustion of anionic dyes. When treated

with chitosan, cotton fibres form cross linking with chitosan resulting in positive active sites

on the fibre surface. As a result, anionic dyes such as direct, acid and reactive dyes can easily

be adsorbed by electrostatic attraction due to the created cationic groups on the fibre surface

(Bhuiyan et al., 2014).

2.7. Previous publications in chitosan treatments of textile fabrics

There has been limited interest in the surface functionalisation of textile fabrics. The number

of treatments that are durable and eco-friendly are even fewer. In this century more focus is

drawn to textile surfaces’ functionalisation using durable and eco-friendly methods. One of

the methods with high potential is that of chitosan treatment.

Depending on the fabric dye, and on what function is desired, chitosan has been used by

several researchers. Most of the research has focused on cotton and wool to promote

antistatic or antimicrobial properties, or even in some cases to improve dyeability. In the case

of polyester the work is even less. Most of the work done aimed at antistatic finishes, and

very little work has been done on the improvement of the dyeability of textile fabrics. The

published work on textile fabrics modification with chitosan will be reviewed below.

50

2.8. Chitosan treatments on cotton

2.8.1. Chitosan treatments to improve antimicrobial properties

Most of the research done on the use of chitosan as an antimicrobial finish , have been

performed on cotton. The biggest obstacle in using chitosan as an antimicrobial agent for

cotton is that of durability (Lim and Hudson, 2003).

Recently, to improve durability, chitosan has been cross-linked to cotton using some

chemicals such as dimethyloldihydroxyethyleneurea (DMDHEU), citric acid, 1,2,3,4-

butanetetracarboxylic acid (BTCA) or glutaric dialdehyde (El-tahlawy et al., 2005; Zhang et

al., 2003; Lee et al., 1999; Chung et al., 1998).

Those chemicals form a cross linking hydroxyl bond between the chitosan and cotton, and

hence provide an antimicrobial finish that is durable for up to 50 wash cycles (Ye et al.,

2005; Ye et al., 2006).

Sang-Hoon Lim et al. created a chitosan derivative, O-acrylamidomethyl-N-[(2-hydroxy-3-

trimethylammonium)propyl] chitosan chloride (NMA-HTCC) which was applied to cotton

fabrics in the presence of an alkaline catalyst. The antimicrobial activities of the NMA-HTCC

treated cotton fabrics were evaluated, the cotton treated with NMA-HTCC at a concentration

of 1% to the weight of fabric showed 100% of bacterial reduction. The activity was

maintained at over 99% even after being exposed to 50 consecutive home laundering

conditions (Lim and Hudson, 2004a).

Shin et al studied the effect of the molecular weight of chitosan on the antimicrobial activity;

this was investigated using three groups of chitosan with different molecular weights (MW)

(1800, 100,000 and 210,000) and similar degrees of deacetylation (86–89%). It was found

that the bacterial reduction rate increased as the MW increased. The MW effect on the

antimicrobial activity of chitosan was more distinctive at low treatment concentrations.

Regardless of the MW, the antimicrobial activity increased with the increase of treatment

concentration, and chitosan with high molecular weight was more effective in inhibiting

bacterial growth than chitosan with low molecular weight (Shin et al., 2001).

Knittel and Schollmeyer studied the permanent fixation of chitosan on cotton surfaces and on

synthetic fibres. In the case of polyester two strategies were followed, the first strategy was

surface-modifying of polyester with dodecylamine to create amino groups on the surface of

51

the polyester. After that they treated the pretreated polyester with chitosan solutions using

anchor chemicals like hydroxydichlorotriazine.

The second way was to modify the chitosan biopolymers with long alkyl chains (n-hexanal)

and fixing this derivative on PET. The antimicrobial activity of those finished textiles has

been determined against some selected bacteria and fungi. It was observed that chitosan

imparts antimicrobial activity to cotton fabrics even when tested under nearly neutral pH

conditions. The finish was durable because of chemical bonding (Knittel and Schollmeyer,

2006).

Chitosan cross-linked cellulose fibres were prepared using non-toxic procedures. Citric acid

was used as the cross-linker with NaH2PO4 as a catalyst in previously UV-irradiated cellulose

fibres. Further heat dried cure processing and washing with detergent, water and acetic acid

(0.1 M) gave a maximum incorporation of chitosan of 27 mg per gram of functionalised

textile. The UV-irradiation induced morphological changes, such as less entangled cellulose

fibres, as observed by scanning electron microscopy, which was prompted to enhance the

chitosan incorporation (Alonso et al., 2009).

Chitosan was used by Chung et al, as an antimicrobial and durable press for cotton. They

used chitosan with citric acid which reacted with the hydroxyl groups in cellulose or cotton

and also formed ester linkage with the amino groups of chitosan. Those kinds of reactions

resulted in durable finishes for cotton. They found that the treatment improved the

antimicrobial properties and the press appearance which was sustained for 20 washes (Chung

et al., 1998).

Lee et al, used chitosan with fluoropolymers to treat samples of 100 % cotton and 55/45 %

wool/polyester with pad-cure and pad-dry-cure methods in order to study their effect on the

microbial properties and the blood repellence properties of these fabrics. Samples showed

reduced microbial activity in the treated samples with chitosan compared with the untreated

samples. The samples treated with chitosan and fluoropolymers showed a durable

antimicrobial finish that was sustained for several washes (Lee et al., 1999).

Öktem treated cotton and polyester/cotton samples with chitosan or chitosan/DMDHEU to

study the treatment effect on the samples’ antimicrobial activity. Another approach within the

study was to dye fabric samples produced from mature and immature cotton fibres and

studying the effect of chitosan or chitosan/DMDHEU treatments on the samples’ dyeability,

and surface morphology (Öktem, 2003).

52

The study showed sufficient and durable antimicrobial effects with the chitosan/DMDHEU

treatment. It also showed improvement in the colour yield of dyed immature cotton fabrics

compared to the mature ones. Scanning electron microscopy (SEM) showed some changes in

the morphology of the chitosan/ DMDHEU treated samples compared to untreated samples as

shown in figures 2.14 and 2.15. Treated samples had a smoother surface than untreated

samples which clearly can affect the samples’ handle (Öktem, 2003).

Figure 2.14: SEM of untreated cotton fibres Figure 2.15: SEM of chitosan/DMDHEU

treated cotton fibres

Teli et al extracted chitosan from shrimp shells, and used it with DMDHEU and other

chemicals as finishing formulations to impart several characteristics such as wrinkle

reduction, antibacterial and flame retardant properties. Physical properties for the treated

samples such as tensile strength, bending length, yellowness index and functional properties

like crease recovery angle, antibacterial activity and flame retardncy were evaluated as well.

The finished fabric showed excellent crease recovery, antibacterial properties and flame

retardancy which were durable even after 20 washes (Teli et al., 2013).

Ferrero et al. studied the treatment of cotton samples with chitosan with UV fixation process.

The research team divided the experiment into two parts, the first part was the laboratory

experiments to determine the optimum conditions for the experiment. The second part was a

semi-industrial trial where larger samples were treated with a commercial chitosan solution

and then UV cured to study the possibility of industrial scale use of the results. The research

revealed a better antibacterial properties of the cotton samples pretreated with chitosan and

UV cured (Ferrero et al., 2015).

This antibacterial properties where tested after up to 30 washing cycles with remarkable

results. They also found that in the laboratory scale experiment they had to dry the chitosan

53

treated samples before the UV curing in order to get a satisfactory results (Ferrero et al.,

2015).

On the contrary in the industrial scale pretreated cotton samples could be wet UV cured and

yet give great results. It was found that by using chitosan by 0.3% of fabric weight in the

industrial experiment, they were able to achieve a remarkable antibacterial properties on the

cotton that lasted for 30 cycle without compromising the fabric properties such as the handle

and the breathability (Ferrero et al., 2015).

2.8.2. Chitosan treatments to improve mechanical properties

Kuo-Shien Huang & al. degraded chitosan to low molecular-weight chitosan with H2O2 and

then used the combination of low molecular-weight chitosan and DDHEU as a finishing

agent for cotton fabrics. They concluded that the crease recovery angle and the treated fabric

strength were better than the untreated samples, and also that the yellowing index and

softness decreased (Huang et al., 2008).

The anti-wrinkle property of the treated samples was decreased after washing 20 times, the

softness of the fabric was improved, and after the wash treatment the strength of the fabric

decreased slightly (Huang et al., 2008).

Strnad et al studied which pre-treatment of cotton fibres is more suitable for an after

treatment with chitosan from the mechanical and sorption properties point of view. They

treated the cotton fibres with different pre-treatments i.e. alkali treatment, bleaching,

demineralisation, and oxidisation using KIO4 solutions. The results showed that even the mild

oxidation worsen the mechanical properties for cotton fibres, while the cotton oxidisation

with chitosan treatment didn’t make any difference to the breaking point and elongation

(Strnad et al., 2008).

Chitosan treatment also increased the moisture absorption of the treated cotton fibres. They

also found that depending on the molecular weight of the chitosan used, the contact angle

with water changed. The hydrophilicity of the treated fibres increased with the chitosan with

lower molecular weight, but chitosan with higher molecular weight decreased it (Strnad et al.,

2008).

54

2.8.3. Chitosan treatments to improve dyeability

Mehta and Combs studied the use of chitosan after treatment to cover the undyed neps of

immature cotton in fabrics that had been already dyed. Pre-dyed samples also containing

white neps of immature cotton were treated with different concentrations of chitosan by an

exhaust or a pad-batch method and then re-dyed using either a fresh dye bath or the spent dye

bath.

Mehta and Combs found that the optimum concentration in the exhaust method was 0.6% of

fabric weight, and 0.8% chitosan in the pad-batch process. They also found that nep coverage

improved the quality of the dyed fabrics (Mehta and Combs, 1997).

Similarly cotton samples were treated with different concentrations of chitosan using various

application techniques i.e. exhaustion, pad-dry, pad-batch, pad-steam and pad-dry steam, in

order to study the effect of chitosan treatment on the dyeability behaviour of cotton fabrics

(Houshyar and Amirshahi, 2002).

It was found that the best treatment technique was the pad-dry method; the chitosan treatment

increases the exhaustion of reactive dyes, and the samples dyed immediately after chitosan

treatment exhibited higher colour strength than those kept for 48 hours before dyeing. A

slight reduction in the light and wash fastness in the treated samples were also observed

(Houshyar and Amirshahi, 2002).

In a parallel study, cotton fabrics were treated with a mixture of chitosan with different

molecular weight and 4,5-dihydroxy-1,3-dimethyl-2-imidazolidinone (DHDMI) to

investigate the effect of molecular weights of chitosan on the dyeability of treated fabrics.

The results showed that chitosan improved the dye uptake of direct and acid dyes. The dye

uptake increased with the increase of the molecular weight of chitosan (Shin and Yoo, 1998).

In the case of reactive dyes, the uptake increased slightly in the alkaline condition as the

molecular weight of chitosan decreased. The uptake of direct and acid dyes increased as the

molecular weight of chitosan increased. It was found that chitosan treatment did not affect the

colourfastness to washing, but slightly decreased the colourfastness to wet crocking, it also

affected other properties of treated fabric, i.e. it resulted in lower wrinkle recovery, stiffer

handle, and higher breaking strength as the molecular weight of chitosan increased (Shin and

Yoo, 1998).

55

In another attempt chitosan was used as a fixing agent on cotton fabrics for the natural dye

Annatto. Jajpura looked at the effect of applying chitosan on cotton to improve fixation of the

natural dye Annatto and fastness properties of the dyed cotton samples. He also studied the

effect of using chitosan before, during and post the dyeing process to find the best method for

using chitosan as a mordant for the natural dye Annatto (Jajpura, 2016).

After accessing the colour values and colour fastness of the dyed samples, the results showed

improvement in the colour yield and the fastness properties of the dyed cotton samples when

using chitosan as mordant before and after the dyeing process. Also improvement of the

antibacterial properties and the tensile strength was noticed (Jajpura, 2016)

Bhuiyan et al., used chitosan treatment in dyeing cotton with reactive dyes in order to reduce

the use of electrolytes. The aim was to have a salt free dyeing of cotton since waste water

from the dyeing process forms a huge environmental risk and water treatment would add to

the cost (Bhuiyan et al., 2014).

Samples were treated with chitosan solution at 60 °C for 60 minutes before dyeing in a

reactive dye bath without the use of electrolytes. They noticed increase in the dye exhaustion

after treating them with chitosan. They also found that by increasing the chitosan

concentration in the pre-treatment, the absorption of the dye significantly increased. They

explained that chitosan treatment of cotton samples increased the cationic sites on the fibre,

which would increase the fabric absorption of reactive dye. They concluded that the chitosan

pretreated samples gave similar or higher K/S values and fastness properties to those dyed

with salt (Bhuiyan et al., 2014).

Hao et al., used chitosan in the bonding of a synthesized anionic nano-pigment on the surface

of cotton fabrics. After treating cotton samples with different concentrations of chitosan,

samples were dyed in a dye bath containing the synthesised anionic pigment at 60 °C for 60

minutes (Hao et al., 2017).

From the results it was noticed that chitosan could be used as a binding agent to bind

synthesized anionic pigment due to the interaction of amino groups in chitosan with the

anionic nano-pigment. They also found that the pH affects the colour strength of the dyed

samples, by reducing the pH the K/S value was increased to 4 (Hao et al., 2017).

Kittinaovarat studied the use of chitosan to improve the dye absorbance of cotton fabrics,

results concluded that the cotton fabrics treated with chitosan had better depth of shade

compared to the untreated fabrics; this could be contributed to chitosan creating more active

56

sites on the treated fabric surface which increased interaction with dye molecules, which

subsequently led to better depth of shade. The chitosan treated fabrics also exhibited better

washing and light fastness than the untreated ones (Kittinaovarat, 2004).

2.8.4. Chitosan treatments to improve textile printability

Hakeim et al, prepared different molecular weights of chitosan products by treating chitosan

with sodium nitrite in an acidic medium. Cotton fabrics were treated with these prepared

chitosan compounds then printed with natural dyes. It was concluded that by increasing the

molecular weight the colour yield increased, and fastness to dry and wet crocking was good;

also it was found that by decreasing the chitosan molecular weight the prints’ stiffness

decreased (Hakeim et al., 2005).

After treating cotton fabrics with Low Temperature Plasma (LTP), Kan et al, used a mixture

of sodium alginate/chitosan as a printing medium in order to study the effect of LTP

treatment on the colour yield of the treated samples. They found that the mixture of sodium

alginate/chitosan gave 85% colour yield better than samples printed with only sodium

alginate , it gave better colour fastness to washing and rubbing and sharper outline than the

traditional sodium alginate paste alone, and also better antimicrobial properties than the

sodium alginate alone (Kan et al., 2011).

Bu et al, treated cotton samples with chitosan and glycidyl trimethyl ammonium chloride to

form the water-soluble N-(2-hydroxy)propyl-3- trimethylammonium chitosan chloride

(HTCC) coating on the fabric surface to study its effect on ink jet pigment printing. They

concluded that the colour was strengthened by the treatment, the treated samples showed

better washing and crocking fastness than the untreated ones. Samples treated with (HTCC)

also showed better antimicrobial properties than untreated samples even after 20 washes (Bu

et al., 2012).

Cotton fabrics were printed with pigment-based ink jet. These ink-jet-printed fabrics were

treated with chitosan to study the effect of the treatment on the fixation of the pigment based

ink on the cotton. The influence of the molecular weight of chitosan, application method

(pad– dry–cure vs pad–batch), concentration, and pH, on the degree of fixation (DF) of the

pigment-based inks were examined (Momin et al., 2011).

The cotton samples treated with chitosan were evaluated for their colour strength, degree of

fixation, and their colour fastness properties. The samples treated with chitosan with high

57

molecular weight showed complete fixation of the pigment inks on the cotton fabrics. The

degree of fixation drastically decreased in the chitosan with low MW. Both the pad–dry–cure

and pad–batch methods were found to be suitable for chitosan application onto ink-jet-printed

fabrics (Momin et al., 2011).

Choi et al, used chitosan as a replacement for sodium alginate in ink jet printing of cotton

fabrics. They used a mixture of chitosan with acetic acid as a pre-treatment solution. The

samples were padded into the pre-treatment solution. The chitosan pretreated fabrics were

dried in an oven at 80 o

C and cured at 170 o

C for 1.5 minutes; all the pretreated fabrics were

conditioned before digital ink-jet printing. Results revealed that it was possible to replace

sodium alginate with chitosan in the pre-printing solution and that this approach gave

satisfactory colour fastness (Choi et al., 2005).

Yen and Chen studied the use of chitosan as a resist agent for resist printing of cotton. They

printed different concentrations of chitosan in a printing paste containing chitosan, formic

acid and thickening agent. They used chitosan to block the active site of cotton fibres from

reacting with reactive dye. They also studied the effect of the chitosan fixation condition on

the resist print of cotton samples. They successfully used chitosan as a resist agent and found

that the optimum concentration of chitosan was 1.6% (Yen and Chen, 2011).

2.8.5. Nano chitosan on cotton

Wijesena et al., prepared nano chitosan from crab shells in the form of a dispersion, then

added an acid dye to the dispersion and used it for the coloration of cotton fabrics (Wijesena

et al., 2015).

Hebeish et al. prepared nano chitosan by the polymerisation of chitosan at different

concentrations with methacrylic acid and K2S2O8 as initiator. They used the nano chitosan

with a crosslinking agent to improve the ability of cotton in respect of copper sulfate pick up.

This treatment was found to increase the fabric’s antimicrobial and UV protection (Hebeish

et al., 2013). (Hebeish et al., 2013)

2.9. Chitosan treatments on wool

2.9.1. Chitosan treatments to improve antimicrobial properties

Chitosan has been used in wool finishes as an anti-shrinkage agent and for improving wool

dyeability. Differences between treated and untreated wool fabrics are easily seen; the treated

wool usually has different dyeing behaviour from untreated wool. Because of the potential

58

benefits of chitosan treatment on wool numerous studies have been conducted to study the

interaction between chitosan and wool fabrics (Enescu, 2008).

Hsieh et al. used citric acid as a crosslinking agent by mixing it with chitosan to study the

effect of this treatment on the antimicrobial and physical properties of wool. They found that

citric acid did not crosslink with the wool except when the wool was oxidised with potassium

permanganate, and that after wool oxidisation the citric acid reacted with the hydroxyl groups

in both the wool and chitosan, while the amino group of wool allowed the surface to crosslink

with chitosan. They concluded that the treatment led to good antimicrobial and antiseptic

effects, but affected the fabric softness, yellowness, stretching resistance, and elongation

percentage (Hsieh et al., 2004).

Ammayappan and Moses studied the use of chitosan, aloevera, and curcumin as antimicrobial

agents. They used those substances alone and in combination, and found that all those

substances have an antimicrobial effect. They found that the strongest effect originated with

the use of aloevera. They also found that the antimicrobial effect was better when they mixed

aloevera with chitosan compared to mixing chitosan with curcumin (Ammayappan and

Moses, 2009).

Demir et al, used chitosan with silica to give an antimicrobial finish to wool pretreated either

with enzymes or with a mixture of enzymes and hydrogen peroxide. Then they studied the

antimicrobial properties of the pretreated and the untreated samples and studied the

antimicrobial activity of wool samples after repeated washes. They stated that the

pretreatment method affected the wool adsorption and diffusion of chitosan. They also found

the chitosan provided an antimicrobial finish that was sustained for several washes (Demir et

al., 2010b).

In another study they investigated the use of air plasma or argon as a wool pretreatment

before chitosan application. It was found that atmospheric plasma enhanced the wool

attachment to chitosan because it had an etching effect which increased the surface

functionality of the wool. They concluded that the treated samples had good washing

durability even after 10 washing cycles (Demir et al., 2010a).

2.9.2. Chitosan treatments to improve mechanical properties

Erra et al treated wool with low temperature plasma (LTP) to improve surface wettability,

dyeability, and shrink resistance. Samples were treated with chitosan for a durable finish,

59

and were compared with the untreated samples. Chitosan was found to enhance the shrink

resistance, also chitosan adsorption was shown to increase after treatment with air plasma

(Erra et al., 1999).

Shih and Huang studied the mixture of chitosan with polyurethane (PU) as a mixed polymer.

Wool fabrics were treated with this mixture aiming at improving the shrinkage and

antimicrobial properties of woollen fabrics. Results showed that the shrinkage and

antimicrobial properties of woollen fabrics were improved with an increase of polymer

mixture concentration, temperature and time of treatment. This treatment also improved the

wool fabric strength. Results showed that adding chitosan remarkably increased the shrink-

proof and the antimicrobial properties of the treated fabric (Shih and Huang, 2003).

Vilchez et al. studied the application of chitosan on wool fabrics before enzyme treatment to

overcome the damage promoted by the enzymes. The treatment was found to decrease the

felting shrinkage, enhance the whiteness degree, and improve the dyeability of wool (Momin

et al., 2011).

Treatment also formed a protective film on the fabric surface which minimised the wool fibre

damage. Chitosan was found to remain on the wool surface even after enzyme treatment

which reduced the fibre damage. The pretreatment with chitosan also improved the wool

shrink resistance and dyeability. As shown in figure 2.16 to figure 2.19, scanning electron

microscope (SEM) analysis showed that the enzymatic treatment was more evenly distributed

when wool was previously treated with chitosan (Vílchez et al., 2010).

Figure 2.16: Wool fibre treated with

bactosol enzyme for 60 min.

(Vílchez et al., 2010)

Figure 2.17: Wool fibre treated with esperase

enzyme for 60 min. (Vílchez et al., 2010)

60

Figure 2.18: Wool fibre treated with

chitosan and bactosol enzyme for 60

min. (Vílchez et al., 2010)

Figure 2.19: Wool fibre treated with chitosan

and esperase enzyme for 60 min. (Vílchez

et al., 2010)

Roberts and Wood studied the use of chitosan as an anti-shrinking agent for wool fabrics.

They used different molecular weights, various levels of N-acetylation, and imparting N-acyl

groups to chitosan chains. Results showed that the change of molecular weight and N-

acetylation did not affect the wool shrinkage to an appreciable degree, but by imparting N-

acyl groups to chitosan chains the wool samples showed better antifelting properties (Roberts

and Wood, 2001).

To explain this Roberts and Wood proposed that wool is a hydrophobic material, which when

treated with the alkaline peroxide (bleaching) becomes more hydrophilic. However the

chitosan is significantly more hydrophilic than the bleached wool. Therefore by increasing

the chain length of the N-acyl group, an increase in hydrophobicity occurs, which increased

compatibility with the wool fibre surface and enhanced the spread of chitosan on the wool

surface, and thus improved the antifelting behaviour compared to untreated wool (Roberts

and Wood, 2001).

Vílchez et al. used chitosan as a pretreatment before treating wool with proteolytic enzyme.

They studied the physical properties such as the friction coefficient, the compressibility and

thickness, the wearing resistance i.e. weight loss after abrasion, the bursting resistance i.e.

bursting strength and deformation and the surface topography. They found that the chitosan

treatment increased the shrink resistance of wool fabrics, and reduced the damage done by

the enzyme treatment. They also found that the chitosan treatment enhanced the fabric

bursting and wearing resistance (Vílchez et al., 2005).

61

Shahidi et al., used chitosan as an antifelting agent for woollen fabrics. They first pretreated

wool with atmospheric pressure plasma (DBD), and then treated it with chitosan by the

technique of pad-dry cure. They found that the pretreated wool fabrics with DBD followed by

chitosan treatment showed a significant improvement in the shrinkage resistance and

antifelting properties. They also noticed an improve in the dyeability of pretreated wool

fabrics with atmospheric pressure plasma (DBD) and chitosan. The pretreated samples

showed higher colour strength compared to those untreated (Shahidi et al., 2014).

Julià et al, used chitosan as a treatment after oxidisation. They studied the effect of chitosan

molecular weight and the oxidisation method on the shrink resistance and dyeing of wool.

They oxidised the wool samples with either hydrogen peroxide or permonosulphuric acid

(PMS), and then treated those wool samples along with unoxidised samples with chitosan of

various molecular weights (Julià et al., 2000).

They concluded that the oxidisation process affected the wool shrinkage, and that the

peroxide pretreatment resulted in higher shrink-resistance than PMS. By increasing the

molecular weight of chitosan applied, wool shrink resistance increased. The chitosan

treatment increased the dye uptake which could lead to a reduction in dyeing time and

temperature. This subsequently could prevent wool damage and save energy (Julià et al.,

2000).

2.9.3. Chitosan treatments to improve dyeability

In 2001, Yen studied the use of chitosan with nonionic surfactants to enhance wool dyeability

with reactive dyes. He studied the effect of using different concentrations of chitosan on the

colour strength of the dyed samples. Results showed that the chitosan treatment enhanced the

colour strength of the dyed woollen samples, and that by increasing the chitosan

concentration, the colour strength increased. Also a higher concentration of surfactant

resulted in better colour strength of the dyed wool fabric. The optimum concentrations of

chitosan / surfactant were 0.5% chitosan and 1.0% surfactant. The washing and dry rubbing

fastness were very good, and the wet rubbing fastness was good (Yen, 2001).

Ali and El-Khatib pretreated wool with chitosan and lemongrass oil, and studied the effect of

this treatment on the colour strength, fastness properties, whiteness, and the wettability of the

treated fabrics. They concluded that pretreated wool samples had better colour strength and

more level dyeing compared to untreated samples. This treatment lead to higher exhaustion,

62

which meant lower dyeing temperature and reduction in dyeing time. This is of importance in

preventing wool damage and for saving energy (Ali and El-Khatib, 2010).

Dev et al. treated wool fabrics with different concentrations of chitosan then dyed them with

henna which is a natural dye that possessed antimicrobial properties. They studied the effect

of the chitosan treatment on the K/S values and the antimicrobial properties of the samples.

They found that the samples treated with chitosan had higher dye uptake and better

antimicrobial properties. They also stated that the washing, rubbing and perspiration fastness

properties were enhanced after chitosan treatment (Dev et al., 2009).

Periolatto et al. treated wool fabrics with chitosan diluted with acetic acid solution mixed

with photoinitiator to graft chitosan to the wool surface by radical reactions. Results showed

enhanced fabric antimicrobial properties and increased dyeability. The treated samples

durability to laundering showed different behaviour depending on the nature of the

surfactants used in the washing procedure (Periolatto et al., 2013).

Sadeghi et al studied the factors affecting the grafting of wool fabrics with a synthesized

Chitosan-poly (propylene imine) dendrimer (CS-PPI) hybrid. They studied the effect of pH,

temperature, and CS-PPI concentration. They dyed the grafted wool with two reactive dyes

C.I. Reactive Orange 122 (RO122) and C.I. Reactive Red 195 (RR195) (Sadeghi-Kiakhani

and Safapour, 2015).

The results showed an optimum grafting condition at pH 6, temperature of 70 °C, and CS-PPI

concentration of 20 % of fabric weight. It was also found that by grafting the wool with

chitosan-poly (propylene imine) dendrimer, the dyeing temperature could be reduced from 80

°C to 40 °C. They also studied the elimination of salt from the dyeing bath, and the results

showed that the colour strength of the conventially dyed wool fabrics could be obtained by

the grafting of wool with chitosan-poly (propylene imine) dendrimer without using salt in the

dye bath. The colour fastness was observed to be the same against washing, light, crocking

and perspiration between good and acceptable. The grafting of chitosan-poly (propylene

imine) dendrimer on the wool was found to reduce the shrinkage (Sadeghi-Kiakhani and

Safapour, 2015).

Rana et al. experimented the use of chitosan, gamma radiation, and both in the treatment of

wool fabrics to study how this would affect the polymer loading%, k/s value, dye uptake%

and washing fastness of the acid dyed wool samples (Rana et al., 2016).

63

The researchers found that by increasing the concentration of chitosan in the wool treatment,

the polymer loading percentage decreased. The K/S values of treated wool samples with

chitosan increased by the increase in chitosan concentration, but after a certain concentration

of 0.3% the K/S values started to slightly decrease (Rana et al., 2016).

For the Gamma radiation, the K/S values of treated samples were higher than untreated

samples, the K/S values increased up to 10 kilogray (kGy) gamma radiation then K/S values

started to decrease with the increase in gamma radiation. They concluded that modification of

wool fibre with chitosan and gamma radiation increased the dye fixation and fastness

properties of the dyed wool samples (Rana et al., 2016).

Ristić et al studied the use of corona discharge (CD) with chitosan to improve woollen

fabrics’ sorption and dyeability. They assessed the physical and chemical properties with X-

ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) (Ristić et al.,

2010).

Results showed that the wettability and dyeability of woollen fabrics were increased with the

CD treatment, and the combined CD and chitosan treatment. it was also concluded that by

increasing the chitosan concentration the colour intensity increased, and that the samples

treated with both CD and chitosan had the highest colour strength (Ristić et al., 2010).

Wool fabrics were treated with deacetylated chitosan along with a crosslinking agent; citric

acid. The effect of using different chitosan concentrations and curing conditions i.e.

temperature and time were also studied. The changes between untreated and treated woollen

samples were examined, and the effect of the treatment on the crease recovery angle,

yellowness, tensile strength, and dyeability was observed (Gawish et al., 2012).

Results indicated that using deacetylated chitosan along with a crosslinking agent (citric acid)

improved the woollen fabric physical and chemical properties. Results of treated samples also

showed an increase in the dye exhaustion and colour strength compared to untreated samples.

Samples treated with chitosan and citric acid had better dye exhaustion and colour strength

than those treated only with chitosan (Gawish et al., 2012).

Pascual and Julià used chitosan with hydrogen peroxide in an alkaline medium to improve

wool felting properties and dyeing behaviour. They found that chitosan treatment increased

the dye rate, and improved wool wettability and shrinkage. They also concluded that the

viscosity of the chitosan solution played an important role in wool antishrinkage. They stated

that by increasing the viscosity, the shrink resistance increased (Pascual and Julià, 2001).

64

Yen used a mixture of chitosan and nonionic surfactant to overcome the chitosan weak

binding and uneven distribution. Results showed improvement in chitosan distribution on

wool surface, and produced better colour strength and deeper and more vivid colour without

increasing the dye concentration. Dyed samples showed improvement in fastness properties

compared to untreated samples (Yen, 2001).

2.9.4. Chitosan treatments to improve printability

Abou-Okeil and Hakeim used chitosan as a pretreatment to enhance the metal binding in the

mordanting process with the aim to improve wool printability with natural dyes. The results

indicated that colour strength and wash fastness of the pretreated printed wool samples were

enhanced compared to the untreated samples. Results also indicated that by increasing the

chitosan molecular weight and concentration the colour strength and washing fastness of the

treated samples increased (Abou-Okeil and Hakeim, 2005).

Other studies used chitosan as a thickening agent to be used in textile printing. Abdou et al

used mixtures of chitosan and gelatinised starch as thickeners in textile screen printing using

natural dye. They used the mixture to print cotton, wool, nylon, polyester and their blends

and studied the effect of this new mixture on the K/S values of the printed samples (Abdou et

al., 2012).

The results showed that the chitosan- gelatinised starch mixture gave higher colour strength

results than normal thickeners, better colour fastness properties for washing, crocking and

perspiration for the printed samples compared to those printed with traditional thickeners. It

also showed that chitosan increased the fabric dye uptake and antimicrobial properties of the

samples (Abdou et al., 2012).

2.9.5. Nano-chitosan treatment for wool

The effect of chitosan particles size on the antimicrobial properties of wool fabrics was

studied by Sahan and Demir. The work focused on the effect of using synthesized nano-

chitosan particles and comparing it to using bulk chitosan. The effect of using a combination

of plasma- chitosan treatment, and silver loaded chitosan on the antimicrobial properties of

wool fabrics were studied (Şahan and Demir, 2016).

They studied the effect of chitosan on the antibacterial activity of wool fabrics. Results

showed that nano chitosan has greater antibacterial activity than bulk chitosan treated fabric.

65

This was due to its larger surface area. Sahan and Demir also studied the effect of these

treatments on the air permeability of the treated fabrics (Şahan and Demir, 2016).

Air permeability is known as air velocity in millimetres per second which is passing through

the fabric at a given pressure difference. The air permeability is mainly dependent on

thickness and porosity. They observed a decrease in the air permeability of chitosan and nano

chitosan treated wool compared to untreated wool, which is the result of the deposition of

chitosan particles on the surface of the wool fibres (Şahan and Demir, 2016).

2.10. Chitosan treatment for polyester

Behary studied polyester surface functionalisation with chitosan. He treated PET with a

deacetylated chitosan solution after pretreatment with atmospheric plasma; compared with

the untreated samples. Results showed that chitosan had successfully coated both untreated

PET and plasma treated PET, resulting in nonwovens with high capacity for surfactant

adsorption at pH 7 at 30°C (Behary et al., 2012).

Results indicated that the increased hydrophobic behaviour in the presence of chitosan

coating on PET nonwovens without plasma activation gave the best surfactant sorption

results (Behary et al., 2012).

Chitosan was used as a surface treatment of polyester, the PET surface was hydrolysed with

caustic soda solution to impart the (-COOH) groups on the polyester surface. Results showed

that the tensile strength of the polyester fabrics decreased greatly with the alkali treatment but

recovered with the chitosan treatment (Enescu, 2008).

2.10.1. Chitosan treatments to improve the antimicrobial properties

Chang et al grafted the polyester surface with chitosan after treating it with atmospheric

pressure plasma. They evaluated fibre properties and antimicrobial properties after treatment.

The results showed that the best antimicrobial effect was obtained after polyester fabrics were

treated by atmospheric pressure plasmas for 60 to 120 sec. then grafted with chitosan (Chang

et al., 2008).

By increasing the plasma treatment time, samples showed an increase in the hydrophilicity of

PET fabrics. They concluded that PET fabrics modified with atmospheric pressure plasma

and chitosan at these conditions were antibacterial and safe for human skin from allergies

(Chang et al., 2008).

66

Wang et al coated polyester fabrics with chitosan/poly (vinyl pyrollidone) (CHI/PVP) in

order to study the effect of the treatment on the bacterial activity of the surface of polyester.

To enhance the attachment of CHI/PVP on the polyester surface, they pretreated polyester

with polyetherimide and polyacrylic acid and crosslinking agents (Wang et al., 2012).

Results showed that the coating created a highly hydrophilic surface with low roughness.

Bacterial activity on the polyester surface was significantly reduced. They also stated that the

pretreatment significantly enhanced the adherence of the CHI/PVP coating on the polyester

surface (Wang et al., 2012).

Sophonvachiraporn et al. prepared an antimicrobial finished polyester fabric by treating it

with chitosan, following a dielectric barrier discharge (DBD) plasma treatment. After plasma

treatment the hydrophilic property of the PET surface was characterised by measuring the

contact angle. XPS analysis showed the creation of oxygen-containing polar groups, which

resulted in an increase of the surface hydrophilicity (Sophonvachiraporn et al., 2011).

Sophonvachiraporn et al. then immersed the plasma treated polyester fabrics in a chitosan

acetate aqueous solution. The results showed clear disappearance of the oxygen-containing

polar groups, which indicated an interaction between those active groups and chitosan. They

concluded that the treated PET possessed an exceptionally high antimicrobial activity

(Sophonvachiraporn et al., 2011).

S. Wazed Ali et al., studied the preparation of chitosan nanoparticles and silver loaded

chitosan and compared it to normal sized chitosan in a matter of antibacterial properties.

Nanoparticles were found to be more thermally stable than bulk chitosan. They concluded

that treated polyester fabrics showed acceptable antibacterial activity at 90% and above at

very low concentration of 0.2%, whereas the bulk chitosan gave only 58% activity at the

same concentration (Ali et al., 2011).

2.10.2. Chitosan treatments to improve textile mechanical properties

Abdel-Halim et al treated polyester fabric with chitosan in order to study the effect of this

treatment on the mechanical properties of the polyester fabrics. After treatment, the nitrogen

content was measured to estimate if the chitosan was successfully deposited on the polyester

surface (Abdel-Halim et al., 2010).

Results revealed that treating polyester with chitosan improved the water uptake capacity

without affecting the fabric mechanical properties. This could be attributed to the hydroxyl

67

groups being introduced to the polyester surface by chitosan, which increased the fabric’s

ability to absorb more water and moisture from the air. This also increased the polyester

fabrics’ electrical conductivity and thus improving their antistatic properties (Abdel-Halim et

al., 2010).

He et al., prepared PEGylated chitosan derivatives and used it to modify PET fabrics. First

they treated the PET surface with oxygen plasma and then treated the etched samples with the

PEGylated chitosan derivatives with different concentrations. They noticed the increase of

functional groups i.e., C=O, C-O, and -OH and surface roughness on the surface of plasma

treated PET samples compared to untreated samples (He et al., 2014).

They also noticed the forming of a film after the treatment of the PET samples with the

PEGylated chitosan modification. The combination of oxygen plasma and PEGylated

chitosan observed to minimise the breaking strength and elongation of PET fabric, increased

the moisture regain and decreased the contact angle (He et al., 2014).

Another research in this area studied the treatment of polyester surface with low temperature

oxygen plasma and N,O-carboxymethyl chitosan and observed their effect on the antistatic

and antimicrobial properties of polyester (Lv et al., 2016).

Lv et al., found that by treating the polyester fabrics with low temperature oxygen plasma, a

large amount of polarized oxygen was deposited on the surface of polyester. Furthermore by

treating the oxygen plasma deposited polyester with N,O-carboxymethyl chitosan, a

significant change of the treated polyester mechanical and antimicrobial properties were

achieved (Lv et al., 2016).

Results indicated that the plasma treatment changed the PET fabric surface and increased the

deposition of carboxymethyl chitosan on the fabric surface. The deposition of carboxymethyl

chitosan on the polyester surface introduced some polar groups i.e. OH, NH2 and COOH on

the fabric. This significantly improved the wettability of the polyester samples. The research

also found that carboxymethyl chitosan could reduce much more static charges on the PET

fabric surface than low-temperature plasma treatment alone (Lv et al., 2016).

2.10.3. Chitosan treatments to improve textile dyeability

Manyukova and Safonov treated polyester and polyamide fabrics with chitosan, before

dyeing them with reactive dyes. They studied the effect of chitosan concentration on the

colour strength of the dyed fabrics, and found that this treatment enhanced the fabric

68

properties and increased the colour strength and fastness. The results also showed that by

increasing the chitosan concentration the colour strength increased. They also stated that

chitosan swelling improved the fabric sorption (Manyukova and Safonov, 2009).

Park et al. used chitosan as a mordant in dyeing polyester fabric with natural dye C. sappan

L and compared the dyeing with that applied using a conventional metal mordant. Results

showed a remarkably high colouring and dye uptake, this also reduced the dyeing time. They

also concluded that this method could be a more ecofriendly process compared to the

traditional method which needs excessive use of dye chemicals (Park et al., 2008b).

Walawska et al treated polyester and cotton/polyester fabrics with chitosan to improve their

dyeability. They pretreated the samples with a solution of NaOH, and then treated the

pretreated samples with chitosan; finally the treated samples were dyed with direct dyestuff.

Results obtained showed that the colour strength increased with the increase of chitosan

deposition on the fabric surface. Also it appears that the treated samples showed better colour

fastness to rubbing and washing (Walawska et al., 2003).

2.10.4. Chitosan treatments to improve printability

Bahmani et al., used chitosan both as thickener and binding agent in pigment printing on

polyester. He prepared a printing paste containing mixtures of chitosan, pigment and acetic

acid. Rheological behaviour of chitosan pigment paste had a much lower yield point than

commercial printing paste but it was applicable. Colour fastness of the chitosan samples gave

satisfactory colour fastness to rubbing, washing and light. They also stated that the only

drawback was that the colour strength was decreased and that the prints had much higher

stiffness (Bahmani et al., 2000).

Ibrahim et al pretreated polyester fabrics with a solution containing chitosan, DMDHEU,

MgCl2. 6H2O, and citric acid as a mixed catalyst and Polyethylene glycol (PEG), cured the

treated samples at 120 °C for 3 minutes and then they printed the samples with disperse dyes

(Ibrahim et al., 2013a).

Results showed that it is possible to use the incorporation of chitosan with PEG and

DMDHEU to improve the printability of polyester fabrics. They concluded that using

chitosan/PEG/DMDHEU improved the colour strength and fastness properties of the

polyester samples printed with disperse dye (Ibrahim et al., 2013a).

69

Ibrahim et al pretreated polyester, polyester⁄wool, polyester⁄cotton and polyester⁄viscose

woven fabrics with monochlorotriazinyl β-cyclodextrin (MCT-b-CD), chitosan or

ethylenediamine, then transfer printed the samples to study the effect of these pretreatments

on the colour strength and UV protection of the printed samples. Results showed that all the

pretreatments applied gave darker depth of shade, better fastness properties, and higher

ultraviolet-protecting functions (Ibrahim et al., 2010).

Noppakundilograt et al pretreated polyester samples with chitosan, N-[(4-dimethyl

aminobenzyl)imino] chitosan (DBIC), N-[(2-hydroxy-3-trimethylammonium) propyl]

chitosan chloride (HTACC), glycine (Gly), and a mixture of chitosan and glycine, as a

pretreatment before printing with pigment based ink jet inks (Noppakundilograt et al., 2010).

Experimental results revealed that the HTACC treatment resulted in the highest K/S, the

deepest colour hue and saturation, and also produced prints with the sharpest and smoothest

outline. They concluded that the ionic interactions between the amino groups of the chitosan

and the anionic charged pigments, also the Van der Waals and hydrophobic interactions

between the polyester and the pigments helped increasing the printing film adhesion to the

polyester surface, which meant more satisfactory colour fastness (Noppakundilograt et al.,

2010).

2.11. Chitosan treatment on cotton / polyester blends

Blended fabrics, especially Poly/cotton blinds are vastly used in the textile industry but yet

there is so little amount of published researches in this field.

Researchers studied the use of chitosan to improve the antimicrobial properties of cotton /

polyester blends. The use of chitosan to improve the printability of cotton / polyester fabrics

with pigments in one step printing technique was investigated. A combination of chitosan,

choline chloride, triclosan derivative, hyperbranched poly amide-amine/silver or zinc oxide

nanoparticles were used in the pigment printing paste and then the prints were cured using

microwave curing. Results showed remarkable antibacterial properties even after 20 washes.

Colour strength values also increased and colour fastness was good to very good (Ibrahim et

al., 2013b).

Muzaffar et al., studied the synthesis of chitosan based polyurethane (PU) dispersion. They

applied this emulsion to different printed and dyed poly/cotton fabrics using the pad/dry/cure

method, this was to study the effect of this treatment on the physical properties of the fabrics

70

i.e. bending, stiffness, crease recovery angle, and Air permeability. The mechanical

properties i.e. pilling tensile strength of the blended fabrics were also evaluated. Results

showed a noticeable improve of physical and mechanical properties of the treated samples

compared to the un-treated samples (Muzaffar et al., 2016).

71

3. Chapter Three: Methodology

3.1. Introduction

As this research aims at:

Enhancing dyeability and printability of fabrics made of cotton, polyester and their

blends without using the traditional auxiliaries in the colouration process in a more

economically and eco-friendly way.

Enabling a swift response to the market and fashion changes during the same season.

Dyeing polyester with commercially available acid dyes, producing differential

printings on different textile materials and in producing resist prints on PET fabric

and its blends.

This lead the work conducted in this research to be divided into three parts as explained in

below.

1- The first part discusses improving the dyeability of polyester and poly/cotton fabrics

with chitosan treatment, in this part process optimum conditions will be used as a base

for the second part.

2- The second part studies the creation of a new technique for textile printing using

differential printing. The aim of using this technique is to produce a two shaded

design of the same colour using one dye bath.

Differential printing is done by printing chitosan on the fabrics under investigation and then

allowing them to be dyed later using the required shades up to the market demand at that

time.

This technique relies on the fact that chitosan printed design will attract more dye stuff than

the rest of the fabric in the dye bath to produce heavier shade that the rest of the fabric which

is not printed with chitosan, by this two shaded design could be printed using one dye bath.

3- Finally the third part studies the possibility of resist printing a hydrophobic material

such as polyester -which is not the ideal material for resist printing- by using chitosan.

Through these three parts, a set of materials, apparatuses, standard methods and analysis are

used to achieve the research objectives, these will be discussed thoroughly in this part.

72

3.2. Materials

3.2.1. Fabrics

Different fabrics have been used to carry out this research, these are listed below:

100% polyester (35gm/m2)

100% cotton (54 gm/m2)

50% cotton -50% polyester (26 gm/m2)

65% cotton- 35% polyester (34 gm/m2).

3.2.2. Chemicals

Different chemicals have been used in this investigation, these are listed below:

Chitosan from crab shells with high molecular weight was obtained from Sigma

Aldrich Japan.

Acetic acid glacial of 99% concentration, supplied by VWR chemicals.

Formic acid of 90% concentration supplied by fisher scientific, UK.

Sodium hydroxide by Fisher chemicals UK.

Acid dye Nylanthrene Navy C-WG supplied by crompton and knowles europe

S A. Sandolan Blue E-2GL 200% supplied by Sandoz chemicals LTD UK.

3.3. Apparatus

Different apparatuses have been used to carry out the tests required in this research, these are

listed below:

A horizontal/vertical padder type HVF, supplied by Werner Mathis AG Switzerland

was used for padding textile samples in chitosan solution.

Mathis labomat beaker infrared dyeing system was used for dyeing all textile samples

throughout this work.

A Werner Mathis AG Switzerland lab dryer was used for thermal curing of textile

samples after treatment.

A Datacolor 650™ spectrum was used for colour fastness measurements of treated

samples.

73

3.4. Design of experiments

In order to fully investigate the chitosan treatments related factors, various aspects where

studied to investigate the optimum conditions for chitosan treatments of textile fabrics.

In each part of this work, four parameters have been investigated. Several levels were

investigated for each parameter. Three repeats of each sample were done for each level of

each parameter.

This was to insure accuracy of the findings. Those parameters where applied on cotton,

polyester, and cotton/ polyester blends of; (50%-50%), and (65%-35%) fabrics, to study the

applicability of the studied techniques on different types of materials i.e. natural fibres,

synthetic fibres, and their blends, and to study the effect of increasing the synthetic fibre

content within the fabric on the fastness properties of the treated samples.

A summary of the factors considered for the current investigation and their levels is listed

below.

3.4.1. Part one: Using the padding process to improve the dyeability of cotton,

polyester, and cotton/polyester blends.

NaOH concentrations i.e. 5, 10, 15, 20 and 25 gm/L on the colour strength of the

pretreated polyester, 50% polyester- 50% cotton, and 65% cotton- 35% polyester were

used to study the effect of NaOH concentration on the treatment process. An optimum

NaOH concentration of 15 gm/L where chosen, and used for the pretreatment of PET,

50% polyester- 50% cotton, and 65% cotton- 35% polyester samples throughout the

rest of this part experiments.

Studying the effect of chitosan concentration; 5, 10, 15, 20, and 25 gm/L on the colour

strength of the pretreated cotton, polyester, 50% polyester- 50% cotton, and 65%

cotton- 35% polyester. An optimum chitosan concentration of 20 gm/L where chosen,

and used for the treatment of PET, 50% polyester- 50% cotton, 65% cotton- 35%

polyester, and cotton samples throughout the rest of the experiments.

Temperatures of 120, 140, 160, 180, 200 and 220 °C were being used in this part of the

research and their effect on the colour strength of the pretreated cotton, polyester, 50%

polyester- 50% cotton, and 65% cotton- 35% polyester was investigated.

Studying the effect of chitosan fixation time by using; 1, 2, 3, and 4 minutes on the

colour strength of the pretreated cotton, polyester, 50% polyester- 50% cotton, and

65% cotton- 35% polyester.

74

3.4.2. Part two: Using chitosan in producing differential printings on different

textile materials

The effect of NaOH concentrations; 5, 10, 15, 20 and 25 gm/L on the colour strength

of the pretreated polyester, 50% polyester- 50% cotton, and 65% cotton- 35%

polyester were studied in this part of the research was conducted in part one to find out

if the chitosan application method (i.e. padding or printing) had an effect on the

optimum NaOH concentration in the pretreatment of experiment samples. An optimum

NaOH concentration of 15 gm/L where chosen, and used for the pretreatment of PET,

50% polyester- 50% cotton, and 65% cotton- 35% polyester samples throughout the

rest of the experiments.

Chitosan fixation temperatures of 120, 140, 160, 180, 200, 220 °C were used to study

their effect on the colour strength of the pretreated cotton, polyester, 50% polyester-

50% cotton, and 65% cotton- 35% polyester.

Effect of chitosan fixation time of 1, 2, 3 and 4 minutes on the colour strength of the

pretreated cotton, polyester, 50% polyester- 50% cotton, and 65% cotton- 35%

polyester was studied.

Effect of chitosan concentration; 5, 10, 15, 20, and 25 gm on the colour strength of the

pretreated cotton, polyester, 50% polyester- 50% cotton, and 65% cotton- 35%

polyester was investigated.

3.4.3. Part three: The use of chitosan in producing resist printing on different textile

materials

In this part NaOH was used as a pre-treatment for polyester, 50% polyester- 50%

cotton, and 65% cotton- 35% polyester, as explained in part one and two with NaOH

concentration of 15 gm/L as an optimum NaOH concentration from the findings of part

one and two. NaOH was also used as a resist agent in the resist pate used in this part.

Therefore the effect of NaOH concentration in the resist printing paste , on the colour

removal of the resist printed polyester, 50% polyester- 50% cotton, and 65% cotton-

35% polyester samples compared to direct printed samples of each material was

studied.

A steam thermos fixation method was chosen in this part for the fixation of resist

printed samples. Therefor a fixation temperatures of 120, 140, 160, 180, and 200 °C

were used to study the effect of fixation temperature of the chitosan printed, NaOH

resisted samples on the colour removal of the resist printed ( polyester, 50% polyester-

75

50% cotton, and 65% cotton- 35% polyester samples) compared to direct printed

samples of each material.

A set of fixation time fixation of 15, 30 and 45 minutes where used to study the effect

of fixation time for chitosan printed NaOH resisted samples, on the colour removal of

the resist printed (polyester, 50% polyester- 50% cotton, and 65% cotton- 35%

polyester samples) compared to direct printed samples of each material.

3.5. Repeated procedures

Throughout the work carried out in this research, a set of standard procedures were carried

out to investigate the properties of the studied textile samples. Those procedures varied

between fabrics pretreatment, chitosan preparation, and chitosan application on textile

samples. These are listed below.

3.5.1. Fabric preparation

A scouring process was performed on cotton, polyester, 50% polyester-50% cotton, and 35%

polyester- 65% cotton fabrics using 3% on the weight of the fabric (owf) caustic soda, and

0.5% sodium bicarbonate (owf) in a water bath at 100 ᵒC for 60 minutes. Fabrics were then

air dried overnight and then cut into 25 cm X 10 cm samples.

3.5.2. Polyester and poly/cotton pretreatment (polyester hydrolysis)

Polyester and cotton/ polyester samples were treated with a solution of different

concentrations of sodium hydroxide (5, 10, 15, 20, 25 gm/ L) and liquor ratio (L:R) 1:20.

The treatment was done at 80 °C for 30 minutes. The samples were then rinsed with distilled

water and 3% acetic acid.

3.5.3. Chitosan preparation

Chitosan solutions were prepared attributed to previous published procedure explained in

(Park et al., 2008a), and a concentration of 20 gm/L where chosen after finding of first part.

A solution of 20 gm/L of chitosan flaks of high viscosity, 3% acetic acid at L:R 1:10 was

used in this work.

The chitosan preparation was formed at room temperature through stirring with a mechanical

stirrer for 2 hours to insure homogeneity. Textile samples were then treated with the prepared

chitosan solutions either by padding or printing, and then cured all subsequently to insure

sustainability.

76

3.5.4. Chitosan application techniques on the studied textile samples

3.5.4.1. The application of chitosan using padding technique

To study improving the dyeability of polyester and poly/cotton fabrics by chitosan treatment,

prepared textile samples (scoured cotton, with scoured and pretreated polyester, 50%

polyester-50% cotton, and 35% polyester- 65% cotton textile samples) where padded in a

chitosan solution prepared as explained previously in 3.5.3. This was done using a A vertical

padder type HVF, supplied by Werner mathis AG Switzerland.

3.5.4.2. Using silkscreen printing technique for chitosan application on textile

fabrics

Prepared textile samples ( scoured cotton, with scoured and pretreated polyester, 50%

polyester-50% cotton, and 35% polyester- 65% cotton textile samples) where printed with a

chitosan printing paste prepared with the following recipe:

X Chitosan

3% Acetic acid

Y Water

____________________

1000 g.

Where X = (5, 10, 15, 20 g/L)

This was done using a traditional flat silkscreens with dimensions 45 X 35 cm and mesh

count of 43 threads per cm supplied by handprinted UK.

3.5.5. Dyeing process

Grafted samples with chitosan were dyed with commercially available acid dye in a dyeing

bath containing:

2% dye (of substrate weight);

5% sodium sulphate;

4% formic acid.

The dye bath started with sodium sulphate, and formic acid, at pH 2-3 and L:R 1:20 , then

the dissolved dye was added and the pH was checked to make sure the pH stayed in the 2-3

range. Samples were treated for 15 minutes at 40 °C., and the temperature was increased to

100 °C over 30 min. and samples were dyed for 30 minutes.

The dyeing process was done on A Mathis labomat Beaker infrared dyeing system.

77

3.6. Samples analysis

3.6.1. Colour evaluation

Colour strength measurements of the dyed samples were carried out using a

spectrophotometer. The colour strength (K/S values) of the dyed samples was determined by

applying equation 1:(Elnagar et al., 2014)

𝐊𝐒⁄ =

(𝟏 − 𝐑)𝟐

𝟐𝐑 (𝟏)

Where K is the coloured samples’ surface absorption, S is the scattering caused by the

coloured substrate surface and R is the decimal fraction of the reflectance of the treated

substrate (Elnagar et al., 2014).

The chitosan treated samples’ K/S values were evaluated and compared to those of the

untreated samples.

3.6.2. Colour fastness evaluations

3.6.2.1. Colour fastness to crocking

This test is designed to determine the resistance of the colour of textile materials to rubbing

off and staining other materials. The test was done on a Crockmaster by James H. Heal & Co

Ltd, an agreeable apparatus within the Technical Manual of the American Association of

Textile Chemists and Colourists (AATCC) (BS.EN.ISO-105-X12:2002) .

In this test a desized, bleached, unfinished (50 mm) squares (± 2 mm) rubbing cotton fabric

were used to cover a rubbing finger comprised of a cylinder of (16 ± 0,1) mm diameter

moving forward and backward in a straight line along a (104 ± 3) mm track on the coloured

specimen, fixed in the Crockmeater with a downward force of (9 ± 0,2) N.

Rubbing samples and specimens were conditioned in an atmosphere of (20 ± 2)°C for four

hours before conducting the test.

During the test each coloured specimen was fixed to the baseboard of the testing device

(Crockmaster by James H. Heal & Co Ltd) so that the long direction of the specimen follows

the track of the device.

In the crocking test, the specimens of the coloured textile are rubbed with a dry rubbing cloth

(dry rubbing) and with a wet rubbing cloth (wet rubbing). In the dry rubbing a conditioned

dry rubbing cloth is fastened over the end of the rubbing finger. The rubbing finger with the

78

dry cotton cloth fastened on it was moved at a rate of one cycle per second, rub forward and

backward in a straight line 20 times, 10 times forward and 10 times backwards , along a track

of (104 ± 3) mm on the dry coloured specimen, with downward force of (9 ± 0,2) N.

In wet rubbing the rubbing cloth was firstly weighted, and then thoroughly soaked in distilled

water and reweighted again to ensure moisture take-up of 95% to 100%. After that the same

procedure as dry rubbing is conducted using a wetted rubbing cloth.

Test rubbing clothes were air dried then assessed by the grey scale for staining. (BS.EN.ISO-

105-X12:2002).

3.6.2.2. Colour fastness to domestic and commercial laundering

A domestic washing test (BS-EN-ISO:6330, 2012) was done on five chitosan treated acid

dyed samples of optimum conditions for each material (cotton, polyester, 50% cotton/ 50%

polyester blends, and 65% cotton/35% polyester blends) and results were compared to dyed

samples with zero chitosan treatment.

The samples were loaded into a horizontal front loading Miele Hydromatic W698 standard

washing machine with Polyester/Cotton, with ratio of load to ballast of 1/1.

A 20 grams of referenced detergent; ECE phosphate reference detergent type 3 without

optical brightening agent were added to the washing load. The washing cycle was done at 60

°C followed by 4 rinsing and spinning cycles.

The specimens and the ballast were immediately removed from the washing machine into

tumble dryer (Beko Sensor Drying). The load was tumble dried at the normal high heat

setting for 60 minutes. After drying one sample of each material was removed from the load

and the same procedure was repeated all over again until the last sample was washed for five

cycles. Washed samples were evaluated according to grey scale rating for the change in the

colour of the specimen according to (BS-EN-ISO:6330, 2012).

3.6.2.3. Colour fastness to perspiration

Colour fastness to perspiration is done to measure how fast the colour is for human sweat. In

this test chitosan padded samples were evaluated for colour fastness for perspiration,

according to (BS.EN.ISO:105-E04, 2009).

Coloured samples measuring (40 ± 2) mm × (100 ± 2) mm were attached to a multifibre

adjacent fabric complying with ISO 105-F10 of the same size. The coloured samples attached

79

to the multifibre adjacent fabric (the composite specimen) were immersed in one of two

solutions alkaline or acidic both containing histidine as follows:

Alkaline solution

The alkaline solution was freshly prepared with 0.5 gm/L of L-histidine monohydrochloride

monohydrate (C6H9O2N3·HCl·H2O) supplied by The British Drug Houses (BDH)

Biochemical, 5 gm/L of sodium chloride (NaCl), and 5 gm/L of disodium hydrogen

orthophosphate dodecahydrate (Na2HPO4·12H2O) supplied by The British Drug Houses

(BDH) GPR.

The solution was brought to pH 8 (± 0.2) with 0.1 mol/l sodium hydroxide solution.

Acid solution

The acidic solution was freshly prepared with 0.5 gm/L of L-histidine monohydrochloride

monohydrate (C6H9O2N3·HCl·H2O) supplied by The British Drug Houses (BDH)

Biochemical, 5 gm/L of sodium chloride (NaCl) and 2.2 gm/L of sodium dihydrogen

orthophosphate dihydrate (NaH2PO4.2H2O) supplied by The British Drug Houses (BDH)

GPR.

The solution was brought to pH 5.5 (± 0.2) with 0.1 mol/l sodium hydroxide solution

(BS.EN.ISO:105-E04, 2009).

The test procedure was done by placing each composite specimen in a flat-bottomed dish,

covering it with the prepared solution (alkaline or acidic) in a liquor ratio of 50:1, and then

soaking it in the solution for 30 minutes at the room temperature.

Each composite specimen was then placed between two acrylic plates to remove the excess

solution from the composite specimen (BS.EN.ISO:105-E04, 2009).

This process was repeated with all composite specimens; each composite specimen was

stacked between two acrylic-resin plates measuring approximately 60 mm × 115 mm × 1,5

mm. in size.

All acrylic plates with the composite specimens sandwiched between them were staked in a

standard testing device supplied by S.D.L. International Limited, consisting of a stainless

steel frame which have a weight-piece of mass approximately 5 kg and base of 60 mm × 115

mm closely fitted above the acrylic plates with the composite specimens between them. So

that a pressure of 12.5 kPa is applied on the tested specimens (BS.EN.ISO:105-E04, 2009).

80

The testing device along with the composite specimens were placed in a vertical position, in

an electrical oven for 4 hours at (37 ± 2) °C for 4 hours. The composite specimens were then

removed from the oven, coloured samples and multifibre specimen were separated and left to

air dry overnight (BS.EN.ISO:105-E04, 2009).

All testing specimens were evaluated on the datacolor spectrum 650 TM using the grey scale

for staining. Also the changes of depth of the shade in the tested samples were evaluated

according to the grey scale for colour change.

3.6.2.1. Scanning Electron Microscope analysis

Scanning Electron Microscope (SEM) is a powerful instrument which enables the

observation and characterization of materials surfaces on a local scale (Goldstein et al.,

2012).

In this research samples of untreated PET, cotton and their blends (50% cotton - 50% PET ,

and 65% cotton - 35% PET) compared to chitosan treated samples of optimum conditions

were titanium plated then SEM photos were taken to demonstrate the surface changes

between un treated and treated samples with chitosan.

3.7. Statistical analysis

Statistical analysis is a process of evaluating data using analytical and logical reasoning to

examine each set of data provided. This form of analysis is just one of the many steps that

must be completed when conducting a research experiment. Data from various experiments is

gathered, reviewed, and then analysed to form some sort of conclusion (Ennos, 2007).

In this research a set of tests and analysis were conducted using the mathematics computer

programme Stategraphics Centurion XV by Statpoint Inc. to analyse the findings of the

research and to determine if these findings are significant or not.

A data analysis for an experiment, i.e. the effect of chitosan fixation temperature on K/S

values of chitosan padded cotton samples would go through a set of steps to analyse the

findings, this example is shown below:

The value of mean µ (the average value of the measurements), standard deviation σ (a

measure of spread of a group of measurements from the mean)(Ennos, 2007), and standard

error SE (measurement of the difference between the sample and the true mean) (Hanneman

et al., 2012) were calculated for each sample according to equations 2, 3, and 4.

81

µ =∑ 𝑿𝒊

𝑵 (2)

Where

Xi = Sub value of observations

N = Number of observations(Ennos, 2007)

𝛔 = √∑(𝐗𝐢− µ)𝟐

𝐍 (3)

Where

µ = Mean value for observations

Xi= Sub value of observations

N= Number of observations (Ennos, 2007)

𝐒𝐄 = 𝛔/√𝐍 (4)

Where:

σ = Standard deviation; a measure of the amount by which a group of data is different from

their mean.

N = Number of observations (Ennos, 2007).

In the results and discussion section of this research, the mean values for each set of data are

presented in a point graph to show how is the variable i.e. fixation temperature as shown

below in figure 3.1, is affecting the K/S values of the investigated sample.

The standard error values are represented as error bars; a bars drown upwards and downwards

from the mean which represents the standard errors, to show how spread the sample repeats

from the mean value. Figure 3.1 shows the means and standard errors for the effect of

fixation temperature on the K/S values of the chitosan padded cotton samples.

82


values of the chitosan padded cotton samples

A regression model is done to quantify the liner relationship between two sets of paired

measurements, and to produce an equation that could be used in the prediction of new values

when the variable changes. The equations for each factor could be seen in appendix A, B, and

C.

The equation of the fitted model is:

𝐲 = 𝐚 + 𝐛𝐱 (5)

Where

y = Independent variable which in this research K/S value

a = Constant

b = Slope or the gradient of a straight line

x = Variables i.e. temperature

The results were then fitted into a regression model which describes for example the

relationship between the fixation temperature and K/S values of chitosan padded PET

samples, as shown below.

These data are presented in Appendix A, B, and C in the graphs showing the plots of fitted

models, where the blue line represents the fitted model, the red lines represent the upper and

the lower prediction limits and the violet lines represent the upper and lower confidence

limits for the fitted model.

Figure 3.2 shows the plot of fitted model illustrating the effect of fixation temperature on the

K/S values of the chitosan padded cotton samples

Means and standard errors of fixation temp effect on the K/S of cotton samples

Temperature (°C)

K/S

0 120 140 160 180

0

2

4

6

8

83

Figure 3.2: Plot of fitted model illustrating the effect of fixation temperature on the K/S

values of the chitosan padded cotton samples

A T-test was conducted on the K/S data for each experiment to compare two means and to

show if they are different from each other. The T-test also shows how significant the

differences are by calculating P-value.

The P-value is the probability that the results from the data occurred by chance. P-values are

from 0% to 100%, A P-value of 5% is 0.05. A P-value of 0.05 (5%) is accepted and means

the data is valid (Ennos, 2007).

An ANOVA test is a way to find out if an experiment results are significant or not. Basically,

it tests a group of data to see if there’s a difference between them. The only problem with

Anova is that the results of the Anova test will show if there is a difference in means,

however, it won’t pinpoint which means are different. This is why a multiple range test was

done to measure specific differences between pairs of means. Results of Anova tests and

multiple range test could be also seen in appendix A, B, and C.

Plot of Fitted Model of fixation temperature effect on K/S of cotton samples

Temperature °C

K/S

0 20 40 60 80 100 120 140 160 180 200 220 240

0

2

4

6

8

http://www.statisticshowto.com/mean/

http://www.statisticshowto.com/what-is-statistical-significance/

http://www.statisticshowto.com/probability-and-statistics/probability-main-index/

http://www.statisticshowto.com/what-is-statistical-significance/

http://www.statisticshowto.com/mean-difference/

84

4. Chapter Four: Using the padding process to improve the

dyeability of cotton, polyester, and cotton/polyester blends

4.1. Introduction

5. Disperse dyes are insoluble in water; they are used in dyeing polyester which has a compact

and crystalline structure. To achieve stable aqueous dispersions while dyeing polyester

fabrics, dispersing agents are applied with disperse dyes.

6. The glass transition temperature of polyester is around 80° C which is considered to be high,

this requires applying high temperature when dyeing polyester fabrics with disperse dyes in

order to achieve high dyeability rates (Fité, 1995).

To avoid the use of high temperatures, helping agents are used to speed up the dyeing process

in order to reduce the heat energy hence increasing the cost effectiveness of the dyeing

process (Fité, 1995).

Carriers with low molecular weights such as amines, aromatic hydrocarbons, phenols and

ethers are absorbed quickly in the dyeing process and are used to speed up the dyeing rate of

polyester fabrics under atmospheric pressure and without using very high temperatures (Fité,

1995).

Despite the advantages of using the carriers in the dyeing process, sometimes polyester

fabrics can be subjected to partial plasticising when using the carriers and this is not desirable

as it affects the structural properties of polyester fibres (Fité, 1995).

In this chapter the use of chitosan was studied in order to improve the dyeability of polyester

fabrics with acid dyes to avoid the problems associated with disperse dyeing.

Polyester/cellulose blends are one of the popular blends; they have the advantages provided

by both fibre types i.e. cotton and polyester. Cotton fibres provide the blend with good

absorption for moisture which in return reduces the static electricity and hence increases the

comfortability of such blending; while polyester fibres provides the blend with good physical

properties i.e. enhanced tensile strength, dimensional stability, abrasion resistance and easy

care advantage for the produced blends (Ingamells, 1993).

On the other hand blended fabrics are a challenge to dye; the requirements for dyeing

hydrophobic fibres like polyester vary from the requirements to dye hydrophilic fibres such

as cotton. Although polyester and cotton fibres need completely different techniques in the

dyeing process but for production and cost effectiveness purposes new single-bath operations

85

have been developed in order to dye these two different fibres existing in the same fabric in

one bath using disperse and vat dyes or disperse and reactive dyes (Ingamells, 1993).

These techniques are relatively expensive and require special dyes that are stable under

different conditions, this is why in this research the aim is to improve the dyeability of

polyester/cellulose blends using chitosan treatments to be dyed in one bath using acid dye.

4.2. Initial experimental approaches

The research work had to go through several initial trials to find the most suitable approach to

start the research with; these trials are explained below.

4.2.1. The optimum temperature for sodium hydroxide NaOH pretreatment of

polyester

Samples of 100% polyester (35gm/m2) fabric were pretreated with NaoH with different

concentrations (1, 2, and 3% o.f.w) at different temperatures (40, 60, and 80° C) for (30,45,

and 60 minutes). Samples were then washed with distilled water, immersed in a 3% acetic

acid solution and then treated with 0.2% chitosan of low molecular weight and liquor ratio

1:20 in an exhaustion bath at 60° C for 45 minutes. After dyeing, Samples showed no trace of

colour which led to further investigations.

4.2.2. Effect of increasing chitosan of low molecular weight concentration on the colour

strength of polyester samples

After failing in accomplishing a satisfactory result in the previous experiment, the same

procedure was done with higher concentration of low molecular weight chitosan. The same

procedure was done with chitosan concentrations of (2, 4, 6% o.f.w), at exhaustion

temperature 100° C for 60 minutes After dyeing samples gave unsatisfactory results, the

experiment was terminated. Figure 4.1 shows a photos of the produced samples.

86

Figure 4.1: Samples for initial trials of effect of increasing chitosan of low molecular

weight concentration on the colour strength of polyester samples

4.2.3. The use of pad- dry- cure process instead of exhaustion process for chitosan

treatment

Several trials of the use of the exhaustion method with chitosan pretreatment of 100%

polyester (35gm/m2) fabric were studied. In another direction, after pretreatment with NaOH,

polyester samples were padded with a solution of 2 % chitosan of low molecular weight with

1% acetic acid, and L:R 1:20 in a pad- dry- cure process.

Samples fixation was carried at (60, 80, and 100° C) for (4, 6, 8, and 10 min). Samples were

then dyed with acid dye Nylanthrene Navy C-WG. The results showed good chitosan fixation

on polyester samples. Samples were in light blue while it should be a navy-blue.

It was concluded that the use of the pad- dry- cure process in chitosan treatment was better

than the exhaustion process in chitosan treatment, but the work needed further investigation.

Figure 4.2 shows the samples of initial trails for applying the use of pad- dry- cure process

instead of the exhaustion process for chitosan treatment.

87

Figure 4.2: Samples of initial trails for the use of pad- dry- cure process instead of the

exhaustion process for chitosan treatment

4.2.4. The use of high molecular weight vs. low molecular weight chitosan

A high molecular weight chitosan was used instead of low molecular weight chitosan.

After pretreatment with a solution of 20% NaOH, and liquor ratio (L: R) 1:20. at 80° C for 30

minutes, a solution of 2% high molecular weight chitosan and 1% acetic acid and liquor ratio

(L: R) 1:10 was prepared.

Polyester samples were padded in the high molecular weight chitosan solution and then cured

at 100° C for 8 minutes. Samples showed good colour, samples were in light blue while it

should be a navy-blue. The conclusion was that the use of high molecular weight chitosan

was better than low molecular weight chitosan, but the work needed further investigation.

4.2.5. The use of basic dyes

An experiment was carried out using basic dye; Maxilon BLUE S-L 200% obtained from

Ciba Dyes and Chemicals, Cheshire, instead of acid dye Nylanthrene Navy C-WG.

100% cotton (54 gm/m2) and 100% polyester (35gm/m

2) samples were printed with chitosan,

heat fixed and then dyed with Maxilon Blue S-L 200%. The results showed very good

fixation of the chitosan. In the case of cotton samples, the dye was completely absorbed from

the dye bath leaving a clear solution which proves the ability to use basic dye to dye chitosan

printed samples. Figure 4.3 shows the samples of initial trails using Maxilon BLUE S-L

200%.

88

Figure 4.3: Samples of initial trails for the use of basic dye

4.2.6. The use of chitosan with di methylol di hydroxy ethylene urea DMDHEU

compared to the use of chitosan with acetic acid

A study on the use of di methylol di hydroxy ethylene urea (DMDHEU) with chitosan was

conducted and compared to the adopted method through the work; chitosan combined with

acetic acid.

A padding solution of 2% chitosan, 8 gm/L DMDHEU, and 0.8 gm/L ZnCl2 was prepared,

polyester samples were padded in this solution, cured and then dyed. The results showed poor

fixation of chitosan compared to the chitosan-acetic solution.

After curing, the water evaporated leaving a powdery residue on samples that could be

removed easily by hand. The experiment was dismissed for the poor results and the health

issues related to the use of DMDHEU. Figure 4.4 shows the poor results of samples textile

samples using chitosan with di methylol di hydroxy ethylene urea.

Figure 4.4: Samples of initial trials for the use of chitosan with DMDHEU

89

The aforementioned samples were done to find the best way to prepare and apply chitosan on

polyester. Several trials were done using 0.2% chitosan concentration which didn’t give

noticeable results as shown in figure 4.2.

Then a trial of pad-cure-dye method was done instead of exhaustion which gave better

results. Several trials were done after that to get to the point that it could be confirmed that

chitosan is successfully fixed on polyester. The new results are displayed in Figure 4.5, the

successful trial led the way to trying more materials like cotton and cotton/polyester blends

using the same route.

Figure 4.5: Successful sample of polyester fabric padded in chitosan and dyed with acid

dye

4.2.7. Polymer loading calculation

Three samples of each material i.e. cotton, polyester, 50-50%, and 65% cotton- 35%

polyester were cut to the same size; samples were frayed to prevent the loss of any threads.

Samples were kept in a desiccator with calcium chloride to absorb moisture existing in the

samples.

Samples were weighed for 15 days until the weight values were nearly stable, this was to get

the actual weight of the samples without any moisture. Samples were then printed with

chitosan, air dried, weighed and then kept in a desiccator for two weeks. This was done to

calculate how much the uptake of chitosan for each material is. The results are showed in

table 4.1:

https://en.wikipedia.org/wiki/Calcium_chloride

90

Table 4.1. Weight gain after chitosan printing of cotton, polyester, 50% cotton-50%

polyester blend and 65% cotton-35% polyester blend

Before chitosan printing After chitosan printing

Polymer

loading (%)

Weight

1 in

grams

Weight

2 in

grams

Weight

3 in

grams

Average

dry

weight of

untreated

sample

Weight

1 in

grams

Weight

2 in

grams

Weight

3 in

grams

Average

dry

weight

of

treated

sample

Cotton Sample

1 4.2285 4.2232 4.2229

4.2781

gm.

4.3985 4.3809 4.3784

4.448

gm. 3.97%

Cotton Sample

2 4.3580 4.2480 4.2477 4.4167 4.5036 4.4730

Cotton Sample

3 4.3470 4.3447 4.3449 4.5091 4.4930 4.4927

Polyester

Sample 1 2.8386 2.8357 2.8358

3.0084

gm.

2.9925 2.9914 2.9902

3.1136

gm 3.5%

Polyester

Sample 2 3.1 3.0946 3.0938 3.2008 3.1983 3.1984

Polyester

Sample 3 3.0984 3.0971 3.0957 3.1515 3.1516 3.1521

50% cotton-50%

polyester blend 3.0348 3.035 3.0329

3.0493

gm.

3.1456 3.1436 3.1428

3.1572

gm. 3.54%

50% cotton-50%

polyester blend 3.1718 3.0968 3.0965 3.1703 3.1686 3.1681

50% cotton-50%

polyester blend 3.0213 3.0196 3.0184 3.1630 3.1614 3.1608

65% cotton-35%

polyester blend

Sample 1

3.6984 3.6818 3.6809

3.7207

gm.

3.7999 3.7986 3.7982

3.8621

gm. 3.8%

65% cotton-35%

polyester blend

Sample 2

3.9179 3.8732 3.7829 3.9692 3.9693 3.9684

65% cotton-35%

polyester blend

Sample 3

3.7018 3.6994 3.6984 3.8221 3.82 3.8197

The average oven dry weight of untreated and chitosan treated samples were calculated for

each material. Then polymer loading% of each set of samples were determined using

equation 6 (Rana et al., 2016):

91

Polymer loading% = (𝑾𝟐 – 𝑾𝟏)/𝑾𝟏 × 𝟏𝟎𝟎% (6)

Where,

W1=Average dry weight of untreated sample,

W2=Average oven dry weight of sample after treatment.

4.3. Experiments

4.3.1. Chitosan treatment

Samples pretreated with NaOH previously explained in 3.5.2. along with cotton samples were

padded in different concentrations of chitosan in padding solutions of (5, 10, 15, 20, 25

gm/L) with 3% acetic acid, and L:R 1:10 as explained in 3.5.3. Samples were cured at (120,

140, 160, 180, 200, 220 °C), for (1, 2, 3, and 4 minutes) to study the optimum conditions for

chitosan fixation.

4.3.2. Dyeing with acid dyes

Grafted samples with chitosan were dyed with the acid dye Nylanthrene Navy C-WG, in a

dyeing bath containing 2% dye (of substrate weight), 5% sodium sulphate, and 4% formic

acid in a L:R 1:20.

The dye bath starts with sodium sulphate, and formic acid, at pH 2-3 , adding the dissolved

dye and checking the pH, treatment for 15 minutes at 40 °C., finally increasing the

temperature to 100 °C over 30 min. and dye for 30 minutes.

4.3.3. Samples evaluation

4.3.3.1.Colour strength evaluation

Colour strength measurements of the printed samples were carried out using a

spectrophotometer. The colour strength (K/S values) of the dyed samples were determined as

explained in chapter three.

4.3.3.2.Colour fastness to crocking

This test is designed to determine the resistance of the colour of textiles to rubbing off and

staining other materials. The test was done on a Crockmaster by James H. Heal & Co Ltd, an

agreeable apparatus with the Technical Manual of the American Association of Textile

92

Chemists and Colourists (AATCC) as explained in chapter three (BS.EN.ISO-105-

X12:2002).

4.3.3.3.Colour fastness to perspiration

Colour fastness to perspiration was done to measure how fast the colour is for human sweat.

In this test chitosan printed samples were evaluated for colour fastness for perspiration,

according to (BS.EN.ISO:105-E04, 2009) as explained thoroughly in chapter three.

4.3.3.4.Colour fastness to domestic and commercial laundering

A domestic washing test (BS-EN-ISO:6330, 2012) was done on five chitosan printed, acid

dyed samples of optimum conditions from each material (cotton, polyester, 50% cotton- 50%

polyester blends, and 65% cotton-35% polyester blends) and compared to dyed samples with

zero chitosan treatment as explained in chapter three.

4.4. Results and discussions

4.4.1. Effect of sodium hydroxide concentration on the K/S values of chitosan padded

textile fabrics

The following results show the effect of Sodium hydroxide concentration in the pretreatment

of polyester samples, cotton/polyester samples (50%-50%, and 65%-35%) on the chitosan

fixation and K/S values of the dyed samples.

Fabrics were treated with (5, 10, 15, 20 and 25 gm/L) of sodium hydroxide at 80 °C for 30

minutes in L: R 1: 20. After exhaust bath, samples were washed with distilled water and 3%

acetic acid, dried, padded with chitosan solution of chitosan 20 gm/L, 3% acetic acid at L:R

1:10, cured at 180° C for 4 minutes, after that samples were dyed with Nylanthrene Navy C-

WG acid dye and then evaluated for colour strength.

4.4.1.1.Effect of sodium hydroxide concentration on the K/S values of PET samples

As mentioned in the experimental part, three samples of PET fabric where pretreated with

NaOH in an exhaustion bath containing sodium hydroxide of different concentrations (5, 10,

15, 20, 25 gm/ L) and liquor ratio (L:R) 1:20.


water and 3% acetic acid, air dried and then padded in a solution of 20 gm/L chitosan with

3% acetic acid, and L:R 1:10.

93

Samples were cured at 180 °C for 4 minutes then dyed with acid dye; Nylanthrene Navy C-

WG, in an exhaustion dyeing bath containing 2% dye (of substrate weight), 5% sodium

sulphate, 4% formic acid, and L:R 1:20 at pH 2-3.

The dye bath started with a temperature of 40 °C for 15 minutes, then the temperature was

increased up to 100 °C over 30 minutes by increasing the temperature gradually by (2 °C /

min.), samples were dyed for 30 minutes and the K/S values of all the samples were

evaluated on a datacolor 650 spectrophotometer.

Table 4.2 shows the mean K/S values for samples treated by different NaOH concentrations.

Table 4.2: The K/S means values of PET samples treated with different NaOH

concentrations

NaOH concentration (grams) Number of samples K/S mean values

0 3 0.62

5 3 3.91

10 3 4.22

15 3 4.32

20 3 4.78

Figure 4.6: Effect of NaOH concentration on the k/s values of the chitosan padded PET

samples

From figure 4.6, for a given set of NaOH concentration, it is clear that by increasing the

NaOH concentration up to 15 g/L the K/S values increased. The K/S values tend to decrease

with further increase in the NaOH concentration.

Means and standard errors of NaOH conc. effect on K/S of PET samples

NaOH concentration (grams)

K/S

0 5 10 15 20 25

0

1

2

3

4

5

6

94

This could be due to the fact that by increasing the NaOH concentration in the pretreatment

over 15 g/L the NaOH tends to break the open linkages on the polyester surface instead of

opening new ones, this leads to the decrease in colour strength of the samples.

The figure also shows the standard error for each sample i.e. measurement of standard

deviation of sampling distribution (Hanneman et al., 2012).

The results are fitting a regression model which describes the relationship between K/S

values of chitosan padded PET samples and the NaOH Concentration in the pretreatment.

The P-value was less than 0.05, which indicate there is a significant relationship between the

K/S values of chitosan padded PET samples and the NaOH Concentration in the pretreatment

of PET samples at the 95.0% confidence level.

The R2 value of 84.17% indicates that the model as fitted can explain 84.17% of the

variability in K/S values of chitosan padded PET samples.

The multiple range tests showed that there is a significant difference between non treated

PET samples with NaOH and treated samples.

By increasing the NaOH concentration in the pretreatment of PET, the difference is

significant until reaching 15 g/L which is not significantly different to 10 g/L. This again

changes by reaching 20 g/L where the K/S values start to decrease which makes a significant

difference between the means of 15 g/L and 20 g/L groups.

The biggest difference when comparing between untreated and treated samples, was between

0 and 15 g/L. It could be understood from the multiple range tests that the pretreatment of

PET samples with NaOH would make a significant difference on the K/S values of PET

samples.

As a conclusion the optimum NaOH concentration for the pretreatment of chitosan padded

PET samples was found to be 15 g/L NaOH in the pretreatment of PET samples as it gave the

highest values of K/S levels and made the biggest level of difference between treated and

untreated samples.

4.4.1.2. Effect of Sodium hydroxide concentration on the K/S values of 50% cotton- 50%

PET samples

Samples of 50% cotton - 50% PET (Blend 1) were treated with different concentrations of

NaOH according to the same procedure done on PET in part 4.4.1.1.

95

Table 4.3: K/S mean values of blend 1 samples treated with different NaOH

concentrations

NaOH concentration Number of samples K/S mean values

0 3 1.08

5 3 4.29

10 3 4.99

15 3 5.17

20 3 5.22

25 3 5.75

Figure 4.7: Standard errors for the effect of NaOH concentration on the K/S values of

the chitosan padded 50% cotton – 50% PET samples

From figure 4.7, it is clear that the K/S values of 50% cotton – 50% PET samples increases

by the increase of NaOH concentration (up to 15 g/L) in the pretreatment.

By increasing the NaOH concentration further and as expected the K/S values tend to

decrease. This is as explained in section 4.4.1.1 could be due to the fact that by increasing the

NaOH concentration in the pretreatment over 15 g/L the NaOH tends to break the open

linkages on the polyester surface instead of opening new ones which leads to the decrease in

the colour strength of the samples. The figure also shows the standard error for each sample

as explained previously.

A regression analysis showed a model describing the relationship between K/S values of

chitosan padded (50% cotton – 50% PET) samples and the NaOH concentration in the

pretreatment.

Means and standard errors of NaOH conc. effect on K/S of blend 1 samples


K/S

0 5 10 15 20 25

0

1

2

3

4

5

6

96

The P-value is less than 0.05, which shows that there is a significant relationship between the

K/S values of chitosan padded 50% cotton – 50% PET samples and the NaOH Concentration

in the pretreatment of 50% cotton – 50% PET samples at the 95.0% confidence level.

The R2 value of 85.2% means that the model as fitted explains 85.2% of the variability in K/S

values of chitosan padded 50% cotton – 50% PET samples.

The ANOVA analysis showed that the P-value of the F-test is 0 which is less than 0.05,

which means that there are significant differences between the means of K/S values of

chitosan padded (50% cotton – 50% PET) samples, this significant difference varied from

some levels of NaOH concentration to others at the 95.0% confidence level. To tell

which NaOH Concentration is different from others a Fisher's least significant difference

analysis (LSD) was done.

The Multiple Range Tests showed that there is a significant difference between non treated

(50% cotton – 50% PET) samples and NaOH treated samples with concentration of 5 g/l.

When NaOH concentration increased from 5 g/L to 10 g/L in the pretreatment of (50% cotton

– 50% PET) the difference was not significant. Increasing the NaOH concentration again

from 10 g/L to 15 g/L in the pretreatment of (50% cotton – 50% PET) showed a significant

difference again.

This again changes by reaching 20 g/L where the K/S values starts to decrease which makes a

significant difference between the means of 15 g/L and 20 g/L groups. The highest level of

difference was at NaOH concentration of 15 g/L. The Multiple Range Tests along with

Anova and regression analysis could be seen in appendix A.

It could understood from the multiple range tests that the pretreatment of (50% cotton – 50%

PET) samples with NaOH would make a significant difference on the K/S values of (50%

cotton – 50% PET) samples and that the highest level of difference was at level of NaOH

concentration of 15 g/L.


(50% cotton – 50% PET) samples was found to be 15 g/L.

4.4.1.3. Effect of sodium hydroxide concentration on the K/S values of 65% cotton-

35% PET samples

Samples of 65% cotton - 35% PET (Blend II) where treated with different concentrations of

NaOH according to the same procedure done on PET in part (4.4.1.1.).

97

Table 4.4 shows the K/S mean values of blend II samples treated with different NaOH

concentrations.

Table 4.4: the K/S mean values of 65% cotton- 35% PET samples for each NaOH

concentration.

NaOH concentration Number of samples K/S mean values

0 3 1.32

5 3 5.87

10 3 5.97

15 3 6.88

20 3 5.23

25 3 4.17


the chitosan padded 65% cotton – 35% PET samples

Figure 4.8 shows the effect of NaOH concentration in the pretreatment of 65% Cotton- 35%

PET on the K/S values of the chitosan padded 65% cotton – 35% PET samples. From the

figure it could be seen that the K/S values of 65% cotton – 35% PET samples increased by

the increase of NaOH concentration (up to 15 g/L) in the pretreatment. K/S values tend to

decrease by increasing the NaOH concentration. This could be due to that by increasing the

NaOH concentration it tends to break the open linkages on the polyester surface instead of

opening new links, hence decreasing the colour strength.

The results fitted into a simple linear regression describing the relationship between K/S

values of chitosan padded (65% cotton – 35% PET) samples and the NaOH Concentration in

K/S


Means and standard errors of NaOH conc. effect on K/S values of blend 2 samples

0 5 10 15 20 25

0

2

4

6

8

98

the pretreatment. The R2 value of 87.1 % means that the model as fitted explains 87.1 % of

the variability in K/S values of chitosan padded 65% cotton –35% PET samples.

The P-value of 0 in the ANOVA analysis which is less than 0.05 means that there is a

significant differences between the means of K/S values of chitosan padded (65% cotton –

35% PET) samples at the 95.0% confidence level. LSD (Fisher's least significant difference

analysis) was done to determine which NaOH Concentration is significantly different from

another.


(65% cotton – 35% PET) samples with NaOH and treated samples.

It also shows that by increasing the NaOH concentration from 5 g/L to 10 g/L in the

pretreatment of (65% cotton – 35% PET) the difference is not significant. Also increasing the

NaOH concentration from 10 g/L to 15 g/L and from 15 g/L and 20 g/L and 20 g/L and 25

g/L in the pretreatment of (65% cotton – 35% PET) showed a significant difference again.

The highest level of difference was NaOH concentration of 15 g/L. It could be understood

from the multiple range tests that the pretreatment of (65% cotton – 35% PET) samples with

NaOH would make a significant difference on the K/S values of PET samples and that the

highest level of difference was at level of NaOH concentration of 15 g/L.


(65% cotton – 35% PET) samples was found to be 15 g/L.

4.4.2. Effect of chitosan fixation temperature on K/S values of chitosan padded textile

fabrics

The following results show the effect of chitosan fixation temperature on the K/S values of

polyester, 50% cotton-50% PET, 65% cotton-35% PET, and cotton fabrics.

Fabrics were treated with 15 gm/L of sodium hydroxide except for cotton at 80 °C for 30

minutes in L:R 1: 20.

After exhaust bath, samples were washed with distilled water and 3% acetic acid, dried,

padded with chitosan solution of chitosan 20 gm/L, and 3% acetic acid at L:R 1:10, cured at

(120, 140, 160, and 180 °C), in the case of PET samples the experiment was also extended to

200 and 220 °C.

The rest of the samples where fixed up to 180 °C only because by raising the temperature

higher than 180 °C the samples started to burn and turn yellow because of the cotton

99

percentage existing in them. All samples were fixed for 4 minutes, after that samples were

dyed with Nylanthrene Navy C-WG acid dye and then evaluated for colour strength.

4.4.2.1. Effect of chitosan fixation temperature on the K/S values of PET samples

Pretreated PET samples with NaOH solution of 15 g/L were padded in chitosan and thermally

fixed at (120, 140, 160, 180, 200 and 220 °C) to study the effect of fixation temperature on

the K/S values of chitosan padded PET samples.

Table 4.5 shows the mean K/S values of each set of temperature for three samples each.

Table 4.5: The K/S means values of PET samples for each fixation temperature

Temperature Number of samples K/S mean values

0 3 0.62

120 °C 3 1.76

140 °C 3 2.04

160 °C 3 3.39

180 °C 3 4.14

200 °C 3 6.46

220 °C 3 6.78


values of the chitosan padded PET samples

From figure 4.9, for a given set of fixation temperatures, it could be seen that the K/S values

of chitosan padded PET samples increase by the increase of fixation temperature to 200 °C.

By increasing the fixation temperature of chitosan padded PET samples to 220°C the K/S

Temperature (°C)

K/S

0 120 140 160 180 200 220

Mean and standsrd deviation of Temerature effect on K/S of PET samples

0

2

4

6

8

100

values slightly increase with a slightly yellowness caused by chitosan deposited on the

surface of PET samples. The figure also shows the standard error for each sample.

The P-value in the regression analysis is less than 0.05, which shows that there is a

significant relationship between the K/S values of chitosan padded PET samples and the

fixation temperature of PET samples at the 95.0% confidence level.

The R2 value of 96.43 % means that the model as fitted explains 96.43 % of the variability in

K/S values of chitosan padded PET samples.

The ANOVA analysis showed that the P-value is 0 which is less than 0.05 meaning that there

is a significant difference between the mean of K/S values of chitosan padded PET samples

of one set of fixation temperature to anther at the 95.0% confidence level.

Fisher's least significant difference analysis was done to determine which fixation

temperature is significantly different from another.


PET samples and treated samples with chitosan at any set of fixation temperature. It also

shows that by increasing the fixation temperature from 120 °C to 140 °C for PET samples the

difference was not significant, and after that increasing the fixation temperature from 140 °C

to 220 °C, PET samples showed a significant difference.

The highest level of difference was at temperature of 220 °C but this could be due to the

chitosan deposited on the surface of PET samples turning yellow, which would affect the

spectrophotometer reading. It could be understood from the multiple range tests that the

pretreatment of PET samples with chitosan would make a significant difference on the K/S

values of PET samples when fixed and that the highest level of difference was at temperature

of 220 °C.

As a conclusion the optimum fixation temperature of chitosan padded PET samples was

found to be between 200 and 220 °C as it gave the highest values of K/S levels and made the

highest level of difference between untreated and treated samples.

In the next part of this research, a fixation temperature of 200 °C was chosen to be the

optimum fixation temperature for chitosan padded PET samples, to avoid the yellowness of

samples

101

4.4.2.2. Effect of fixation temperature on the K/S values of 50% Cotton- 50% PET

samples

Samples of 50% cotton - 50% PET (Blend 1) where pretreated with NaOH solution of 15 g/L

, then were padded in chitosan and thermally fixed at (120, 140, 160, 180 °C) to study the

effect of fixation temperature on the K/S values of chitosan padded 50% cotton - 50% PET

samples.

It is worth mentioning that a trial was done with fixation temperature of 200 °C but the colour

of the samples changed to yellow because of the existence of cotton percentage in the blend,

which affected the overall colour and would give false results, that is why the fixation

temperature of 200 °C was excluded from the experiment.

Table 4.6 shows the mean K/S values of each set of fixation temperatures for the studied

samples

Table 4.6: The K/S mean values of blend 1 samples for each fixation temperature three

samples each


0 3 1.08

120 °C 3 2.06

140 °C 3 4.3

160 °C 3 5.64

180 °C 3 5.75

Figure 4.10: Effect of fixation temperature on the K/S values of the chitosan padded

50% cotton – 50% PET samples

Temperature (°C)

K/S

Means and standard errors of fixation temp. effect on K/S of blend 1 samples

0 120 140 160 180

0

1

2

3

4

5

6

102

From figure 4.10, it is clear that the K/S values of 50% cotton – 50% PET samples increased

by the increase of fixation temperature of chitosan padded samples. The Highest K/S values

where at 180 °C, after that by increasing the fixation temperature further to 200 °C as

mentioned in previous part, samples colour changed to yellow because of the existence of

cotton percentage in the blend, this affected the overall colour and would give an inaccurate

colour evaluation, that is why the fixation at temperature 200 °C was not carried out, the

figure also shows the standard error for each sample.

The P-value for the regression model was less than 0.05, which shows that there is a

significant relationship between the K/S values of chitosan padded 50% cotton – 50% PET

samples and the fixation temperature of 50% cotton – 50% PET samples at the 95.0%

confidence level. The R2 value of 90.24 % means that the model as fitted explains 90.24 % of

the variability in K/S values of chitosan padded 50% cotton – 50% PET samples.

To determine which fixation temperature is different from another a Fisher's least significant

difference analysis (LSD) was done.

Results also showed significant difference between non treated (50% cotton – 50% PET)

samples and thermofixed samples at any temperature. Increasing the fixation temperature

from 120 °C to 160 °C gave a significant difference.

When increasing the fixation temperature to 180 °C, the increase of K/S values was

insignificant which made an insignificant difference between the means of 160 °C and 180

°C groups.

The highest level of difference was achieved at 180 °C. It could understood that the fixation

of chitosan would make a significant difference on the K/S values of (50% cotton – 50%

PET) samples and that the highest level of difference was at fixation temperature of 160 to

180 °C.

As a conclusion the optimum fixation temperature for the chitosan padded (50% cotton –

50% PET) samples was found to be between 160 and 180 °C because there is no significant

difference between them.

In this investigation a fixation temperature of 180 °C was chosen to be used as an optimum

fixation temperature for (50% cotton – 50% PET) samples.

103

4.4.2.3. Effect of fixation temperature on the K/S values of 65% cotton- 35% PET

samples

Samples of 65% cotton - 35% PET (Blend II) were pretreated with NaOH solution of 15 g/L ,

then were padded in chitosan solution and thermally fixed at (120, 140, 160 and 180 °C) to

study the effect of fixation temperature on the K/S values of chitosan padded 65% cotton -

35% PET samples.

A trial was done with fixation temperature 200 °C as mentioned in (4.1.2.2) but samples

colour changed to yellow again because of the existence of cotton percentage in the blend,

which is why the fixation temperature 200 °C was also excluded from this part of the

research.

Table 4.7 show the mean values of K/S for each set of fixation temperatures.

Table 4.7: The K/S mean values of 65% cotton- 35% PET samples for each fixation

temperature


0 3 1.32

120 °C 3 2.21

140 °C 3 4.5

160 °C 3 5.98

180 °C 3 6.85

Figure 4.11: Means and standard errors for the effect of fixation temperature on the

K/S values of the chitosan padded 65% cotton – 35% PET samples

Temperature (°C)

K/S

0 120 140 160 180

Means and standard errors of fixation temp. effect on K/S of blend2 samples

0

2

4

6

8

104


by the increase of fixation temperature of chitosan padded samples. The Highest K/S values

were at 180 °C. Increasing the fixation temperature to 200 changed the colour of the samples

to yellow as aforementioned, which is why the fixation temperature 200 °C was excluded

from the experiment. The figure also shows the standard error for each sample as explained

previously.

The P-value in the ANOVA table was less than 0.05, which showed that there is a significant

relationship between the K/S values of chitosan padded 65% cotton – 35% PET samples and

the fixation temperature of 65% cotton – 35% PET samples at the 95.0% confidence level.


K/S values of chitosan padded 65% cotton – 35% PET samples.

A Fisher's least significant difference analysis (LSD) was carried out to determine

which fixation temperature is different from another. Multiple range tests showed that there is

a significant difference between non treated (65% cotton – 35% PET) samples and thermos-

fixed samples at any temperature.

Increasing the fixation temperature from 120 °C to 180 °C gave a significant difference. The

highest level of difference was at 180 °C. It is then concluded that the fixation of chitosan

made a significant difference on the K/S values of (65% cotton – 35% PET) samples and that

the highest level of difference was at fixation temperature of 180 °C.

It is concluded that the optimum fixation temperature for the chitosan padded (65% cotton –

35% PET) samples was 180 °C.

4.4.2.4. Effect of fixation temperature on the K/S values of cotton samples

Cotton samples where padded in chitosan solution and thermally fixed at (120, 140, 160, 180

°C) to study the effect of fixation temperature on the K/S values of chitosan padded cotton

samples.

Table 4.8 shows the mean values of K/S for each set of fixation temperature.

Table 4.8: The mean values of K/S for cotton samples treated with different fixation

temperatures


0 3 1.53

120 °C 3 2.05

140 °C 3 4.92

160 °C 3 6.49

180 °C 3 7.19

105

Figure 4.12: Means and standard errors for the effect of fixation temperature on the


K/S values of cotton samples, as shown in figure 4.12 increase by the increase of fixation

temperature of chitosan padded samples. The Highest K/S value was at 180 °C, the fixation

temperature was not raised to 200 °C as mentioned previously, as this caused the colour of

the samples to change to yellow, which would affect the accuracy of the reading of the

spectrophotometer. .

The P-value in the ANOVA table was less than 0.05 showing that there is a significant

relationship between the K/S values of chitosan padded 91.9006 %samples and the fixation

temperature of cotton samples at the 95.0% confidence level.


K/S values of chitosan padded cotton samples.

A Fisher's least significant difference analysis (LSD) was conducted on data to tell

which fixation temperature is different from another, results showed that there is a significant

difference between non treated cotton samples and chitosan padded samples at any fixation

temperature.

Increasing the fixation temperature from 120 °C to 180 °C gave a significant difference. The

highest level of difference occurred at 180 °C. It could be understood that the fixation of

chitosan cotton samples would make a significant difference on the K/S values of cotton

samples and that the highest level of difference was at fixation temperature of 180 °C.

Means and standard errors of fixation temp effect on the K/S of cotton samples

Temperature (°C)

K/S

0 120 140 160 180

0

2

4

6

8

106

As a conclusion the optimum fixation temperature for the chitosan padded cotton samples

were found to be 180 °C.

4.4.3. Effect of chitosan fixation time on the K/S values of chitosan padded textile

fabrics

The following results show the effect of chitosan fixation time on the K/S values of polyester,

50% cotton-50% PET, 65% cotton-35% PET, and cotton fabrics.

Fabrics were treated with 15 gm/L of sodium hydroxide except for cotton at 80 °C for 30

minutes in L:R 1: 20. Samples were washed after the exhaust bath with distilled water and

3% acetic acid, dried, padded with chitosan solution of chitosan 20 gm/L, and 3% acetic acid

at L:R 1:10, cured at 180 °C for cotton, blend 1 and blend 2 and 200 °C in the case of PET

samples.

Samples were fixed for 1, 2, 3, and 4 minutes, after that samples were dyed with Nylanthrene

Navy C-WG acid dye and then evaluated for colour strength.

4.4.3.1.Effect of fixation time on the K/S values of PET samples

PET samples were pretreated with NaOH solution of 15 g/L where padded in chitosan and

thermally fixed at 200 °C for 1, 2, 3, and 4 minutes, to study the effect of fixation time on the

K/S values of chitosan padded PET samples, table 4.9 shows the mean K/S values of each set

of time.

Table 4.9: The K/S mean values of PET samples for each set of fixation time

Time Number of samples K/S mean values

0 3 0.62

1 3 4.23

2 3 4.96

3 3 5.3

4 3 6.61

107

Figure 4.13: Means and standard error for the effect of fixation time on the K/S values

of the chitosan padded PET samples

From figure 4.13, for a given set of fixation time, it could be seen that the K/S values of

chitosan padded PET samples increased by increasing the fixation time to 4 minutes, figure

4.13 also shows the standard error for each sample.

The P-value in the regression analysis is less than 0.05, which shows that there is a significant

relationship between the K/S values of chitosan padded PET samples and the fixation time of

PET samples at the 95.0% confidence level.



The ANOVA analysis showed that the P-value is 0 which is less than 0.05, which means that

there is a significant differences between the means of K/S values of chitosan padded PET

samples from one set of fixation time to another at the 95.0% confidence level.

Fisher's least significant difference analysis was done to determine which fixation time is

significantly different from another. The analysis showed a significant difference between

non treated PET samples and treated samples with chitosan at any set of fixation time. It also

shown that by increasing the fixation time from 2 to 3 minutes for PET samples the

difference is not significant.

Increasing the fixation time from 3 to 4 minutes for PET samples showed a significant

difference. The highest level of difference was at a fixation time of 4 minutes. It could

Means and standard deviation of fixation time effect on K/S values of PET sampl

Time (minutes)

K/S

0 1 2 3 4

0

2

4

6

8

108

understood that the pretreatment of PET samples with chitosan would make a significant

difference on the K/S values of PET samples and that the highest level of difference was at

fixation time of 4 minutes.

The optimum fixation time for chitosan padded PET samples was concluded to be 4 minutes,

as it gave the highest values of K/S levels and made the highest level of difference between

treated and untreated samples.

4.4.3.2. Effect of fixation time on the K/S values of 50% cotton – 50% PET samples

50% cotton – 50% PET samples were pretreated with NaOH solution of 15 g/L, padded in

chitosan and thermally fixed at 180 °C for (1, 2, 3, and 4 minutes). This was to study the

effect of fixation time on the K/S values of chitosan padded 50% cotton – 50% PET samples,

table 4.10 shows the mean K/S values for three samples of each set of fixation time.

Table 4.10: The K/S mean values of 50% cotton – 50% PET samples for each fixation

time for three samples


0 3 1.08

1 3 4.70

2 3 5.02

3 3 5.47

4 3 5.74


of the chitosan padded 50% cotton – 50% PET samples

Means ans standard errors of fixation time effect on K/S of blend 1 samples

K/S

Time(minutes)

0 1 2 3 4

0

1

2

3

4

5

6

7

8

109

From figure 4.14 it is clear that for a given set of fixation time, the K/S values of chitosan

padded 50% cotton – 50% PET samples increased by the increase of fixation time to 1

minute.

By increasing the fixation time of chitosan padded 50% cotton – 50% PET samples to 2

minutes, the K/S values slightly increased, the K/S values increased again by the increase of

fixation time to 3 and 4 minutes.

It is worth mentioning that when the fixation time was 4 minutes, the 50% cotton – 50% PET

samples showed slight yellowness caused by the chitosan deposited on the surface of 50%

cotton – 50% PET samples. The cotton samples colour change to yellow could be also caused

by temperature.



the fixation time of PET samples at the 95.0% confidence level.


K/S values of chitosan padded 50% cotton – 50% PET samples.

To determine which fixation time is significantly different from another, Fisher's least

significant difference analysis was done. Results show that there is a significant difference

between non treated 50% cotton – 50% PET samples and treated samples with chitosan at

any set of fixation time. They also show that by increasing the fixation time from 1 to 2

minutes for 50% cotton – 50% PET samples the difference is not significant, and after that

increasing the fixation time from 2 to 4 minutes for 50% cotton – 50% PET samples showed

a significant difference again.

The highest level of difference was at a fixation time 4 minutes but again this could be due to

the chitosan depositing on the surface of 50% cotton – 50% PET samples, high percentage of

chitosan deposited of the fabric surface can turn its colour into yellow, which is not

preferable as it would affect the spectrophotometer reading.

It could be understood from the results that pretreatment of 50% cotton – 50% PET samples

with chitosan would make a significant difference on the K/S values of PET samples when

fixed, and that the highest level of difference was at fixation time between 3-4 minutes.

As a conclusion the optimum fixation time for chitosan padded 50% cotton – 50% PET

samples was found to be 3 minutes, it gave the highest values of K/S levels and highest level

110

of difference between treated and untreated samples. Fixation time for 4 minutes – although

giving good results- was excluded as it caused yellowness of the samples, to avoid the

yellowness of the samples a fixation time of 3 minutes was chosen to be the optimum fixation

time for chitosan padded 50% cotton – 50% PET samples.


In order to study the effect of fixation time on the K/S values of chitosan padded 65% cotton

– 35% PET samples, samples were pretreated with NaOH solution of 15 g/L then padded in

chitosan and thermally fixed at 180 °C for (1, 2, 3, and 4 minutes), results of the mean K/S

values of each set of time for three samples are shown in table 4.11.


time


0 3 1.32

1 3 5.45

2 3 6.02

3 3 6.26

4 3 6.98




chitosan padded 65% cotton – 35% PET samples increase by the increase of fixation time. It

is worth mentioning again that in fixation time 4 minutes the 65% cotton – 35% samples

Means and standard errors of fixation time effect on K/S values of blend 2

Time (minutes)

K/S

0 1 2 3 4

0

2

4

6

8

111

showed slight yellowness caused by the chitosan deposited on the surface of the samples. The

figure also shows the standard error; measurement of standard deviation of sampling

distribution for each sample as explained previously (Hanneman et al., 2012).





K/S values of chitosan padded 65% cotton – 35% PET samples


there is a significant difference between the mean of K/S values of chitosan padded 65%

cotton – 35% PET samples from one set of fixation time to anther at the 95.0% confidence

level. LSD was done to determine which fixation time is significantly different from others.


65% cotton – 35% PET samples and treated samples with chitosan at any set of fixation time.

It also showed that by increasing the fixation time from 2 to 3 minutes for 65% cotton – 35%

PET samples the difference is not significant, and after that increasing the fixation time from

3 to 4 minutes for 65% cotton – 35% PET samples showed a significant difference again.

The highest level of difference was at a fixation time of 4 minutes but again this could be due

to the chitosan depositing on the surface of the 65% cotton – 35% PET samples as explained

previously.

It could be understood from the multiple range tests that the pretreatment of 65% cotton –

35% 65% cotton – 35% PET samples with chitosan made a significant difference on the K/S

values of PET samples when fixed, and that the highest level of difference was at fixation

time between 3-4 minutes. Results for regression analyses, Anova tables, and The Multiple

Range Tests are listed in Appendix A.

As a conclusion the optimum fixation time for chitosan padded 65% cotton – 35% PET

samples was found to be 3 minutes. Fixation time for three minutes gave the highest values of

K/S levels and made the biggest level of difference between treated and untreated samples,

similar results were also obtained when the fixation time was 4 minutes, but the latest was

excluded for the yellowness issue mentioned previously.

112

4.4.3.4. Effect of fixation time on the K/S values of cotton samples

As mentioned in part 4.4.3 cotton samples were padded in chitosan and thermally fixed at

180 °C for (1, 2, 3, and 4 minutes) to study the effect of fixation time on the K/S values of

chitosan padded cotton samples. Table 4.12 shows the values of K/S of the samples under

study, treated at each set of time.

Table 4.12: The K/S means values of cotton samples for each fixation time


0 3 1.53

1 3 6.09

2 3 6.68

3 3 6.88

4 3 7.08


of the chitosan padded cotton samples


chitosan padded cotton samples increase by the increase of fixation time to 3 minutes. By

increasing the fixation time of chitosan padded cotton samples to 4 minutes, the K/S values

increased but with a slight yellowness caused by the chitosan deposited on the surface of

cotton samples. The figure also shows the standard error for each sample as explained

previously.

Mean and standard errors of fixation time effect on K/S of cotton samples

Time (minutes)

K/S

0 1 2 3 4

0

2

4

6

8

113


values of chitosan padded cotton samples and the fixation temperature. The P-value in the

regression analysis is less than 0.05, which shows that there is a significant relationship

between the K/S values of chitosan padded cotton samples and the fixation time of cotton

samples at the 95.0% confidence level.




cotton samples and treated samples with chitosan at any set of fixation time.

By increasing the fixation time from 2 to 3 minutes and from 3 to 4 minutes for cotton

samples the difference was not significant. The highest level of difference was at a fixation

time of 4.

It could be understood that the pretreatment of cotton samples with chitosan would make a

significant difference on the K/S values of cotton samples when fixed and that the highest

level of difference was at fixation time between 2-4 minutes.

As a conclusion the optimum fixation time for chitosan padded cotton samples was found to

be between 2 and 3 minutes. It gave the highest values of K/S levels and made the biggest

level of difference between untreated and treated samples, same as for fixation time of 4

minutes which was excluded for the aforementioned yellowness issue.

In the following work, for research purposes and to avoid the yellowness of samples a

fixation time of 3 minutes was chosen to be the optimum fixation time for chitosan padded

cotton samples.

4.4.4. Effect of chitosan concentration on the K/s values of chitosan padded textile

fabrics

The following results show the effect of chitosan concentration on the K/S values of

polyester, 50% cotton-50% PET, 65% cotton-35% PET, and cotton fabrics.

All fabrics except for cotton were treated with 15 gm/L of sodium hydroxide at 80 °C for 30

minutes in L:R 1: 20. After exhaust bath, samples were washed with distilled water and 3%

acetic acid, dried, padded with chitosan solutions of (5, 10, 15, and 20 gm/L) concentration,

and 3% acetic acid at L:R 1:10, cured at 180 °C (for cotton samples, blend I and blend II) for

114

3 minutes, and for 3 minutes in 200 °C in the case of PET samples. Samples were dyed after

that with Nylanthrene Navy C-WG acid dye and then the colour strength was evaluated.

4.4.4.1. Effect of chitosan concentration on the K/S values of PET samples

To study the effect of chitosan concentration on the K/S values of chitosan padded PET

samples PET samples were pretreated with NaOH solution of 15 g/L, then padded in chitosan

solutions of (5, 10, 15, and 20 gm/L) concentration and then thermally fixed at 200 °C for 3

minutes.

The values of K/S for three treated samples for each condition were recorded and the mean

K/S values of each set of time were calculated as shown in table 4.13.

Table 4.13: The K/S mean values of PET samples for each chitosan concentration

Concentration Number of samples K/S mean values

0 3 0.62

5 3 1.6

10 3 2.74

15 3 3.83

20 3 5.29

Figure 4.17: Means and standard error for the effect of chitosan concentration on the

K/S values of the chitosan padded PET samples

From figure 4.17, for a given set of chitosan concentration, it could be seen that the K/S

values of chitosan padded PET samples increases increased by increasing the chitosan

concentration. The figure also shows the standard error for each sample.

Chitosan concentration (grams)

K/S

0 5 10 15 20

Means and standard errors of chitosan conc. effect on K/S of PET samples

0

1

2

3

4

5

6

115


relationship between the K/S values of chitosan padded PET samples and the chitosan

concentration at the 95.0% confidence level. The correlation coefficient of 0.99 shows a

strong relationship between the variables under investigation.



The ANOVA analysis showed that the P-value is 0 which is less than 0.05, this means that

there are significant differences between the means of K/S values from one chitosan

concentration to anther at the 95.0% confidence level for chitosan padded PET samples.

Fisher's least significant difference analysis (LSD) was done to determine which chitosan

concentration is significantly different from another. The multiple range tests showed that

there is a significant difference between non treated PET samples and treated samples with

chitosan at any concentration.

The highest level of difference was at when the chitosan concentration was 20 g/L. It could

understood from the multiple range tests that the pretreatment of PET samples with chitosan

would make a significant difference on the K/S values of PET samples at any chitosan

concentration and the highest K/S values could be achieved using 20 g/L of chitosan.

As a conclusion the optimum chitosan concentration for padded PET samples was found to

be 20 g/L, as this gave the highest values of K/S levels and made the biggest level of

difference between treated and untreated samples.

4.4.4.2. Effect of chitosan concentration on the K/S values of 50% Cotton- 50% PET

samples

50% Cotton- 50% PET samples pretreated with NaOH solution of 15 g/L were padded in

chitosan solutions of (5, 10, 15, and 20 gm/L) concentration and thermally fixed at 180 °C for

3 minutes, to study the effect of chitosan concentration on the K/S values of chitosan padded

50% Cotton- 50% PET samples. Table 4.14 show the mean values of K/S of samples treated

at each set of time.

116

Table 4.14: The K/S mean values of 50% cotton- 50% PET samples for each chitosan

concentration


0 3 1.08

5 3 1.78

10 3 2.99

15 3 3.83

20 3 5.21


K/S values of the chitosan padded 50% cotton- 50% PET samples


values of chitosan padded 50% cotton- 50% PET (Blend 1) samples increase by the increase

of chitosan concentration and it also shows the standard error for each sample.

The results fits within simple regression model which describes the relationship between K/S

values of chitosan padded 50% cotton- 50% PET samples and the chitosan concentration.

The P-value in the regression analysis is less than 0.05 indicating that there is a significant

relationship between the K/S values of chitosan padded 50% Cotton- 50% PET samples and

the chitosan concentration at the 95.0% confidence level.


K/S values of chitosan padded 50% cotton- 50% PET samples. LSD was also done to

determine which chitosan concentration is significantly different from another.


K/S

0 5 10 15 20

Means and standard errors of chitosan conc. effect on K/S of PET samples

0

1

2

3

4

5

6

117

Results indicated that there is a significant difference between non treated 50% Cotton- 50%

PET samples and treated samples with chitosan at any concentration.

The highest level of difference was at chitosan concentration of 20 g/L. It could understood

that the pretreatment of PET samples with chitosan would make a significant difference on

the K/S values of 50% Cotton- 50% PET samples at any chitosan concentration and the

highest K/S values could be achieved using 20 g/L of chitosan concentration.

As a conclusion the optimum chitosan concentration for padded 50% Cotton- 50% PET

samples was found to be 20 g/L. This percentage gave the highest values of K/S levels and

made the biggest level of difference between untreated and chitosan treated samples.


samples

Samples pretreated with NaOH solution of 15 g/L where padded in chitosan solutions of (5,

10, 15, and 20 gm/L) concentration and thermally fixed at 180 °C for 3 minutes to study the

effect of chitosan concentration on the K/S values of chitosan padded 65% Cotton- 35% PET

samples. Table 4.15 shows the mean K/S values of samples produced at each set of time.

Table 4.15: The K/S mean values of 65% Cotton- 35% PET samples for each chitosan

concentration


0 3 1.32

5 3 2.86

10 3 3.87

15 3 4.51

20 3 5.36

118


K/S values of the chitosan padded 65% cotton- 35% PET samples


values of chitosan padded 65% Cotton- 35% PET (Blend 1) samples increase by the increase

of chitosan concentration. The figure also shows the standard error for each sample. The

results are fitting a simple regression model which describes the relationship between K/S

values of chitosan padded 65% Cotton- 35% PET samples and the chitosan concentration.


relationship between the K/S values of chitosan padded 65% Cotton- 35% PET samples and


The model as fitted explains 95.5 % of the variability in K/S values of chitosan padded 65%

Cotton- 35% PET samples, this is evident from the R2 value of 95.5 %.

The ANOVA analysis showed that the P-value is 0 which is less than 0.05, meaning that

there is a significant difference between the mean of K/S values of chitosan padded 65%

cotton- 35% PET samples from one chitosan concentration to anther at the 95.0% confidence

level.


65% cotton- 35% PET samples and treated samples with chitosan at any concentration.

Means and standard errors of chitosan conc. effect on K/S of blend 2 samples


K/S

0 5 10 15 20

0

1

2

3

4

5

6

119

The highest level of difference was shown by samples treated with chitosan concentration of

20 g/L. It could be understood from the multiple range results that the pretreatment of 65%

Cotton- 35% PET samples with chitosan would make a significant difference on the K/S

values of 65% cotton- 35% PET samples at any chitosan concentration and the highest K/S

values could be achieved using 20 g/L of chitosan concentration.

As a conclusion the optimum chitosan concentration for padded 65% cotton- 35% PET

samples was found to be 20 g/L. As it gave the highest values of K/S levels and made the

biggest level of difference between untreated and treated samples with chitosan.

4.4.4.4. Effect of chitosan concentration on the K/S values of cotton samples

Cotton samples were padded in chitosan solutions of (5, 10, 15, and 20 gm/L) concentration

and thermally fixed at 180 °C for 3 minutes, to study the effect of chitosan concentration on

the K/S values of chitosan padded cotton samples.

Table 4.16 shows the mean K/S values of each set of time for three samples each.

Table 4.16: The K/S mean values of cotton samples for each chitosan concentration


0 3 1.53

5 3 3.93

10 3 5.52

15 3 6.48

20 3 7.03

Figure 4.20: Means and standard errors for the effect of chitosan concentration on the



K/S

Mean and standard errors of chitosan conc. effect on K/S of cotton samples

0 5 10 15 20

0

2

4

6

8

120


values of chitosan padded cotton samples increased by the increase of chitosan concentration.

The results are fitting a simple regression model which describes the relationship between

K/S values of chitosan padded Cotton samples and the chitosan concentration.


relationship between the K/S values of chitosan padded Cotton samples and the chitosan

concentration at the 95.0% confidence level. The correlation coefficient of 0.96 shows a

strong relationship between the variables.




there are a significant differences between the mean of K/S values of chitosan padded cotton

samples from one chitosan concentration to anther at the 95.0% confidence level


cotton samples and treated samples with chitosan at any concentration.

The highest level of difference was a result of chitosan concentration of 20 g/L. It could

understood from that the pretreatment of cotton samples with chitosan would make a

significant difference on the K/S values of cotton samples at any chitosan concentration and

the highest K/S values could be achieved using 20 g/L of chitosan concentration.

As a conclusion the optimum chitosan concentration for padded Cotton samples was found to

be 20 g/L. As it gave the highest values of K/S levels and made the biggest level of difference

between untreated and treated samples with chitosan.

4.4.4.5. Multiple ANOVA analysis for the effect of chitosan concentration

A multiple ANOVA analysis was done to see if the effect of chitosan concentration would be

significantly different from one type of fabric to another. The ANOVA multiple sample

comparison showed a P value of 0 which is less than 0.05 which means that there is a

significant difference between the means of the 4 fabrics (PET, 50% PET-50% cotton, , 65%

PET- 35% cotton and cotton) at the 95.0% confidence level.

121

Figure 4.21 Means and standard errors for the comparison between chitosan

concentration effects on different fabrics

Figure 4.21 shows the difference between the means for K/S values of the 4 fabrics (PET,

50% PET-50% cotton, and 65% PET- 35% cotton, and cotton) and the standard errors for

each fabric at the 95.0% confidence level.

From figure 4.21, it could be noticed that the effect of chitosan concentration slightly

increases from PET to Blend 1 (50% PET-50% cotton), significantly increases in Blend 2

(65% PET- 35% cotton) and then increases further in cotton.

This could be explained by the increase of cotton percentage in the fabric leading to higher

percentage of chitosan particles fixed to the fabric, causing higher affinity to dye stuff which

leads to an increase in the mean of K/S values.

The small increase in K/S means between PET and Blend 1 (50% PET-50% cotton) is due the

higher fixation temperature that PET samples were fixed at, which led to higher K/S values

than blended samples.

4.5. Samples Evaluation

4.5.1. Colour fastness evaluation

4.5.1.1.Colour fastness to crocking

As explained in chapter three the colour fastness for crocking was done according to

(BS.EN.ISO-105-X12:2002). Results are shown in table 4.17.

PET Blend 1 Blend 2 Cotton

Means and standard errors of chitosan concentration on all fabrics

2.9

3.9

4.9

5.9

6.9M

ean

122

Table 4.17: Fastness to crocking properties of chitosan padded fabrics

Samples Crocking

Dry Wet

Polyester

NaoH concentration

Untreated 5 5

5 gm NaoH 4-5 2-3

10 gm NaoH 4-5 2

15 gm NaoH 4-5 3-4

20 gm NaoH 5 3-4

25 gm NaoH 5 3

Temperature

120°C 4 1-2

140°C 4 1-2

160°C 4-5 2

180°C 4-5 3-4

Time

1 min. 5 3

2 min. 5 3-4

3 min. 5 3

4 min. 4-5 1-2

Ca Concentration

5 gm. 3-4 2-3

10 gm. 4-5 3

15 gm. 4-5 3

20 gm. 4 1-2

Cotton

Temperature

120°C 4 2-3

140°C 4 2-3

160°C 4 3

180°C 4 3

Time

1 min. 4 3

2 min. 4 3-4

3 min. 4 3-4

4 min. 4 3-4

Ca Concentration

5 gm. 4-5 4

10 gm. 4-5 3-4

15 gm. 4-5 3

20 gm. 3-4 3

50% cotton- 50%

Polyester

NaoH concentration

Untreated 5 4

5 gm NaoH 5 3-4

10 gm NaoH 4-5 3

15 gm NaoH 5 3-4

20 gm NaoH 4-5 3-4

25 gm NaoH 5 4-5

Temperature

120°C 5 2

140°C 4-5 2

160°C 4-5 3-4

180°C 5 4

Time

1 min. 4-5 2

2 min. 4-5 2-3

3 min. 4-5 3-4

4 min. 4-5 3-4

Ca Concentration

5 gm. 5 3-4

10 gm. 5 3-4

15 gm. 5 3

20 gm. 5 3

123

50% cotton- 50%

Polyester

65% cotton- 35%

Polyester

NaoH concentration

Untreated 5 4

5 gm NaoH 4-5 2-3

10 gm NaoH 4-5 2-3

15 gm NaoH 5 3-4

20 gm NaoH 4-5 2-3

25 gm NaoH 4-5 2-3

Temperature

120°C 5 2

140°C 4-5 2

160°C 5 3-4

180°C 5 4

Time

1 min. 5 3

2 min. 4-5 2-3

3 min. 5 2-3

4 min. 5 3-4

Ca Concentration

5 gm. 5 2-3

10 gm. 4-5 2-3

15 gm. 5 2

20 gm. 4-5 2

65% cotton- 35%

Polyester

NaoH concentration

Untreated 5 5

5 gm NaoH 4-5 3-4

10 gm NaoH 4-5 3

15 gm NaoH 4-5 3-4

20 gm NaoH 5 3-4

25 gm NaoH 5 3-4

Temperature

120°C 4 2

140°C 4 2

160°C 4-5 3-4

180°C 4-5 3-4

Time

1 min. 5 3

2 min. 5 3-4

3 min. 5 3-4

4 min. 4-5 3-4

Ca Concentration

5 gm. 3-4 3

10 gm. 4-5 3

15 gm. 4-5 2-3

20 gm. 4 3

4.5.1.2.Colour fastness to domestic and commercial laundering

As explained in Chapter three a domestic washing test (BS-EN-ISO:6330, 2012) was done on

five chitosan treated acid dyed samples of optimum conditions of each material (cotton,

polyester, 50% cotton/ 50% polyester blends, and 65% cotton/35% polyester blends), and the

results were compared to the results of dyed samples with zero chitosan treatment.

Samples were evaluated according to grey scale rating the change in colour. The results

showed good fastness to domestic washing as shown in table 4.18.

124

Table 4.18: Fastness properties of chitosan padded fabrics for domestic and commercial

laundering

Samples Washing

First wash Second wash Third wash Fourth wash Fifth wash

Polyester

5 5 4-5 4 4

50% cotton-

50%

Polyester

4-5 4-5 4-5 4-5 4

65% cotton-

35%

Polyester

4-5 4-5 4-5 4-5 4

Cotton 4-5 4-5 4-5 4 4

4.5.1.3.Colour fastness to perspiration

Coulor fastness to perspiration was done as explained in Chapter three, to measure how fast

the colour is for human sweat. In this test chitosan padded samples dyed with acid dye were

evaluated for colour fastness for perspiration, samples were evaluated according to grey scale

rating for staining (BS.EN.ISO:105-E04, 2009).

Results showed poor to moderate t fastness to perspiration as shown in table 4.19.

125

Table 4.19: Fastness properties of chitosan padded fabrics for perspiration

Samples Acid Alkali

Wool Acrylic PET Nylon Cotton Acetate Wool Acrylic PET Nylon Cotton Acetate

Polyester

NaoH

concentratio

n

Untreated 2 3-4 3-4 1-2 2-3 2 1-2 2 2-3 1 1 1

5 gm NaoH 1-2 3-4 3-4 1-2 2-3 2-3 1-2 2 2-3 1 1-2 1

10 gm NaoH 1-2 3-4 3 1 2 2 2 2 2 1 1 1

15 gm NaoH 2 3 3 1-2 2-3 2-3 1-2 2-3 2-3 1-2 1-2 1-2

20 gm NaoH 2 3 4 1-2 2-3 2-3 1-2 2-3 2-3 1 1-2 1-2

25 gm NaoH 2 3-4 3-4 1-2 2-3 2 1-2 2 2-3 1 1 1

Temperature

120°C 1-2 3-4 3 1-2 2-3 2-3 1-2 2-3 2-3 1 1-2 1-2

140°C 1-2 3 3-4 1-2 2-3 2-3 1-2 2-3 2-3 1 1-2 1-2

160°C 2 3 3 1-2 2-3 2-3 1-2 2 3 1 1-2 1-2

180°C 2 3 3-4 1-2 2-3 2-3 2 2-3 2-3 1 1-2 1-2

Time

1 min. 1-2 3-4 3 1-2 2-3 2-3 2 2-3 2-3 1 1-2 1-2

2 min. 2 3 3-4 1-2 2-3 2-3 2 2-3 2-3 1 1-2 2

3 min. 2 3-4 3 1-2 2-3 2-3 2 2-3 2-3 1 1-2 1-2

4 min. 1-2 2-3 2-3 1 1-2 1-2 1 1-2 2 1 1 1

Ca

Concentratio

n

5 gm. 2 3-4 3-4 1-2 2-3 2 1-2 2 2 1 1-2 1-2

10 gm. 2 3-4 3 1-2 2-3 2-3 2 2 2 1-2 2 2

15 gm. 1-2 3-4 3-4 1-2 2-3 2-3 2 2 3 1-2 1-2 2

20 gm. 1-2 3-4 3-4 1 2-3 2-3 2 2 2-3 1 1-2 1-2

50%

cotton-

50%

Polyester

NaoH

concentratio

n

Untreated 2 3-4 3-4 1-2 2-3 2-3 1-2 2 2-3 1 1-2 1

5 gm NaoH 2 3-4 3-4 1-2 2 2 1-2 2 2-3 1 1-2 1

10 gm NaoH 2 3-4 3-4 1-2 2-3 2 1-2 2 2-3 1 1-2 1

15 gm NaoH 2 3 3-4 1-2 2 2-3 1-2 2-3 2-3 1 1 1

20 gm NaoH 2 3-4 3 1-2 2-3 2-3 1-2 2 2-3 1 1-2 1

25 gm NaoH 2 3-4 3-4 1-2 2-3 2-3 1-2 2 2-3 1 1-2 1

Temperature

120°C 2 3-4 3-4 1-2 2-3 2-3 1-2 2-3 3 1 1-2 1-2

140°C 2 3-4 3-4 1-2 2-3 2 1-2 2 2-3 1 1-2 1

160°C 2 3-4 3 1-2 2-3 2-3 1-2 2-3 2-3 1 1-2 1

180°C 2 3 3 1-2 2-3 2-3 1-2 2-3 3 1 1-2 1-2

Time

1 min. 1-2 3 3 1 2 1-2 1-2 1-2 2 1 1 1

2 min. 1-2 3 3 1 2 1-2 1-2 2 2 1 1 1

3 min. 1-2 3 3 1 2 1-2 1-2 2 2 1 1 1

126

4 min. 1-2 3 3 1 2 1-2 1-2 1-2 2 1 1 1

Ca

Concentratio

n

5 gm. 2 3 3-4 1-2 2 2 2 2-3 2-3 1-2 1-2 1-2

10 gm. 2 3 3 1-2 2-3 2-3 2 2 3 1 1-2 1-2

15 gm. 2 3 3-4 1-2 2-3 2-3 2 2-3 2-3 1-2 2 2

20 gm. 2 3 3 1-2 2-3 2-3 2 2-3 2-3 1-2 2 2

56%

cotton-

35%

Polyester

NaoH

concentratio

n

Untreated 2 3 3-4 1-2 2-3 2-3 1-2 2-3 3 1 1-2 1-2

5 gm NaoH 2 3 3 1-2 2-3 2-3 1-2 2 2-3 1 1-2 1

10 gm NaoH 2 3-4 3-4 1-2 2-3 2-3 1-2 2-3 2-3 1 1-2 1-2

15 gm NaoH 2 3-4 3-4 1-2 2-3 2 2 2-3 2-3 1 1-2 1-2

20 gm NaoH 2 3 3 1-2 2-3 2 2 2-3 3 1 1-2 1-2

25 gm NaoH 2 3 3-4 1-2 2-3 2-3 1-2 2-3 3 1 1-2 1-2

Temperature

120°C 2 3-4 3 1-2 2-3 2-3 1-2 2 2-3 1 1-2 1-2

140°C 2 3-4 3-4 1-2 2-3 2 1-2 2-3 2-3 1 1-2 1-2

160°C 2 3-4 3 1-2 2-3 2-3 1-2 2-3 2-3 1 1-2 1-2

180°C 2 3 3 1-2 2-3 3 2 2-3 2-3 1 2 2

Time

1 min. 2-3 3-4 3 1-2 2-3 2-3 1-2 2-3 2-3 1 1-2 1-2

2 min. 2 3-4 3 1-2 2-3 2 1-2 2-3 2-3 1 1-2 1-2

3 min. 2-3 3 3 1-2 2-3 2-3 1-2 2-3 2-3 1 1-2 2

4 min. 2 3 3 1-2 2-3 2 2 2-3 2-3 1 2 1-2

Ca

Concentratio

n

5 gm. 1-2 3 3 1 2 2 1-2 2 2-3 1 1-2 1-2

10 gm. 1-2 3 3 1 2 2 1-2 2-3 2-3 1 1-2 1-2

15 gm. 2 3 3 1-2 2-3 2-3 2 2-3 3 1 1-2 1-2

20 gm. 2 3 3 1-2 2-3 2-3 2 2-3 2-3 1 1-2 1-2

Cotton

Temperature

120°C 2-3 3 3-4 2 2-3 2-3 2 3 3 1-2 2 2

140°C 2 3 3 1-2 2-3 2-3 2 2-3 3 1 1-2 1-2

160°C 2-3 3 3-4 1-2 2-3 3 1-2 2-3 3 1 1-2 1-2

180°C 2 4 4-5 2 2-3 3 1-2 2-3 3 1 1-2 1-2

Time

1 min. 2-3 3-4 3 2 2-3 2-3 2 3 3 1-2 2 2

2 min. 2 3-4 3-4 1-2 2-3 2-3 2 3 3 1 2 2

3 min. 2-3 3 3 2 2-3 2-3 2 3 3-4 1-2 2 2

4 min. 2 3-4 4 1-2 2-3 2-3 1-2 3 3-4 1 1-2 1-2

Ca

Concentratio

n

5 gm. 2 3-4 3-4 1-2 3 2-3 2 2-3 2-3 1-2 2 1-2

10 gm. 2 3 3-4 1-2 2 2 1-2 2 2-3 1-2 1-2 1-2

15 gm. 2-3 3-4 3-4 1-2 2-3 2-3 2 2-3 2-3 1-2 2 1-2

20 gm. 2-3 3 3-4 1-2 2-3 2-3 2 2-3 2-3 1-2 2 2

127

4.5.2. Scanning Electron Microscope (SEM)

Scanning Electron Microscope (SEM) photos were taken of samples before and after chitosan

treatment to capture the physical effect of the chitosan treatment on the surface of the fabrics

handled in this research work.

Figure 4.22: SEM for un treated PET sample

Figure 4.23: SEM for PET sample treated with chitosan at the optimum condition

128

Figure 4.24: SEM for un treated 50% cotton – 50% PET sample

Figure 4.25: SEM for 50% cotton – 50% PET sample treated with chitosan at the

optimum condition


129

Figure 4.27: SEM for 65% cotton – 35% PET sample treated with chitosan at the

optimum condition

Figure 4.28: SEM for un treated cotton sample

Figure 4.29: SEM cotton sample treated with chitosan

130

From previous figures, it could be seen that the chitosan treatment is forming a film like

coating on the fabric and that it is forming crosslinks between fibres which confirms the

formation of the chitosan coating on the fabrics under investigation.

4.6. Conclusion

The work carried out in this chapter lead to successfully dye PET fabrics and their blends

using chitosan pretreatment.

It is also succeeded to dye PET fabrics and their blends with commercially available acid

dyes without the excessive use of carriers and other harmful chemicals.

The optimum Sodium hydroxide concentration in the pretreatment of PET, Blend 1 (50%

Cotton- 50% PET), and Blend 2 (65% cotton – 35% PET) was found to be 15 g/L.

The optimum fixation condition for chitosan padded PET samples was at fixation temperature

of 200 °C for 4 minutes.

The optimum fixation condition for Blend 1 (50% Cotton- 50% PET), and Blend 2 (65%

cotton – 35% PET), and cotton was found to be at fixation temperature 180 °C for 3 minutes.

131

Chapter Five: Differential printing of cotton, polyester, and

cotton/polyester blends with chitosan.

5.1. Introduction

The Fashion market now is vivid with companies looking for unusual, eye catching effects to

boost their sales by producing new styles (Dawson and Hawkyard, 2000).

One of these styles is the differential dyeing. Differential dyeing is a dyeing style that

depends on modifying natural or synthetic fibres to change their affinity for dyes, either by

increasing or decreasing the fibres’ uptake of dye to form a multi coloured textile fabric.

Little research has been performed in the area of differential dyeing and the previous

researches were mainly carried on polyamide fibres used in carpets manufacture. The concept

of nylon differential dyeing depends mainly on the amine end groups in nylon fibres. These

end groups determine the fibre affinity for acid dyes. Increasing the number of the active

groups would increase the fibre affinity for acid dyes leading to darker shades, blocking these

sites will decrease the fibre affinity for acid dyes leading to lighter shades (McGregor, 1977;

Becht et al., 1972; Anton, 1981).

Researchers studied the differential dyeing on textile materials. Wool was dyed by the

differential dyeing method and the difference between orthocortex and paracortess dyeing

behaviour was studied (Dusenbury and Coe, 1955).

Other studies investigated the differential dyeing method on natural fibres i.e. cotton, a

colourless cationic and anionic treatments were applied on cotton yarns, this affected the

yarns dyeability with acid and direct dyes (Clipson and Roberts, 1989; Clipson and Roberts,

1994).

A scarcity of research has been performed in the area of differential dyeing of textiles and

there is no previous work on using this technique in textile printing.

In this stage of the research, the use of chitosan in differential printing of different materials

will be investigated. Differential printing will be performed with chitosan (a non-coloured

paste), the aim of using chitosan is to attract more dyestuff to the areas treated with chitosan

than the rest of the fabric.

This way a two shaded printed design could be obtained using a single dye bath, this should

be useful in designing fabrics with different shades of a single colour.

132

It will also enable factories to vastly respond to market changes in one season i.e. stock of

printed textiles with clear chitosan could be prepared and stored to be dyed with the needed

colour when stock is running low.

In this part chitosan will be used in the printing of cotton, polyester, and cotton/polyester

blends, the ability to use this technique as a differential printing will be investigated as well.

5.2. Experiments

5.2.1. Materials

Scoured and bleached 100% polyester fabric (100g/m2), 100% cotton, 50% cotton: 50%

polyester, and 65% cotton: 35% polyester will be used in this part. Chitosan from crab shells

with high molecular weight obtained from Sigma Aldrich Japan, acetic acid, and acid dye

Sandolan Blue E-2GL 200% by Sandoz chemicals UK were used.

5.2.2. Methods

5.2.2.1. Polyester and Polyester/ cotton blends pretreatment

Polyester and cotton/ polyester samples were treated with a solution of different

concentrations of sodium hydroxide (5, 10, 15, 20, 25 gm/ L) and liquor ratio (L: R) 1:20.

The treatment was done at 80° C for 30 minutes. The samples were then rinsed with distilled


5.2.2.2. Fabric treatment with chitosan

Pretreated samples with NaOH along with cotton samples were manually silkscreen printed,

with different concentrations of chitosan in a printing paste of:

X Chitosan

3% Acetic acid

Y Water

____________________

1000 g.

Where X = (5, 10, 15, 20 g/L)

Samples were cured at (140, 160, 180, 200, 220 °C), for (1, 2, 3, 4 minutes) to study the

optimum conditions for chitosan fixation.

133

5.2.2.3. Dyeing of printed samples

Samples printed with chitosan were dyed with the acid dye Sandolan Blue E-2GL 200%, in a

dye bath containing:


5% sodium sulphate;

4% formic acid.

The dye bath started with sodium sulphate, and formic acid, at pH 2-3, L:R 1:20, the

dissolved dye was added and the pH was checked and the treatment lasted for 15 minutes at

40 °C., finally the temperature was increased to 100 °C over 30 min. and samples were dyed

for 30 minutes. The dyeing process was done on a Mathis labomat uniprogrammer lap dyeing

machine.

5.2.2.4. Samples evaluation

5.2.2.4.1. Colour strength evaluation


spectrophotometer. The colour strength (K/S values) of the dyed samples were determined as

explained in chapter three.

5.2.2.4.2. Colour fastness to crocking

The test was done on a Crockmaster by James H. Heal & Co Ltd, an agreeable apparatus with

the Technical Manual of the American Association of Textile Chemists and Colourists

(AATCC) as explained in chapter three (BS.EN.ISO-105-X12:2002).

5.2.2.4.3. Colour fastness to perspiration

Colour fastness to perspiration was done to measure how fast the colour is for human sweat.

In this test chitosan printed samples were evaluated for colour fastness for perspiration,

according to (BS.EN.ISO:105-E04, 2009).

5.2.2.4.4. Colour fastness to domestic and commercial laundering

A domestic washing test (BS-EN-ISO:6330, 2012) was done on five chitosan printed, acid

dyed samples of optimum conditions from each material (cotton, polyester, 50% cotton- 50%

134

polyester blends, and 65% cotton-35% polyester blends) and compared to dyed samples with

zero chitosan treatment as explained in part three.

5.3. Results and discussion

5.3.1. Effect of sodium hydroxide concentration in the pretreatment of chitosan

printed textile fabrics

The following results show the effect of sodium hydroxide concentration in the pretreatment

of the polyester, cotton/polyester samples (50%-50%, 65%-35%) on the chitosan fixation and

K/S values of chitosan printed, acid dyed samples.

Fabrics were treated with (5, 10, 15, 20, 25 gm/L) of sodium hydroxide at 80 °C for 30

minutes in (L: R) 1: 20. After exhaust bath, samples were washed with distilled water and 3%

acetic acid, dried, printed with a printing paste containing:

20 gm/Kg Chitosan

3% Acetic acid

Y Water

____________________________

1000 g.

Sample were then cured at 180° C for 4 minutes, after that samples were dyed with acid dye

Sandolan Blue E-2GL 200%, and then the colour strength was evaluated.

5.3.1.1. Effect of sodium hydroxide concentration on the K/S values of PET samples

As mentioned in (5.2) three samples of (PET, 50% cotton- 50% PET, and 65% cotton- 35%

PET) fabrics, were pretreated with NaOH in an exhaustion bath containing a solution of

different concentrations of sodium hydroxide (5, 10, 15, 20, 25 gm/ L) and liquor ratio (L:R)

1:20.

The treatment was done at 80°C for 30 minutes. The samples were then rinsed with distilled

water and 3% acetic acid, air dried, and then printed with chitosan printing paste of 20 gm/L

chitosan with 3% acetic acid.

Samples were cured at 180 °C for 4 minutes, then dyed with acid dye Sandolan Blue E-2GL

200%, in an exhaustion dyeing bath containing 2% dye (of substrate weight), 5% sodium

sulphate, 4% formic acid, and L:R 1:20 at pH 2-3. The dye bath started at 40 °C for 15

minutes, then the temperature was increased to 100 °C over 30 min. (2 °C / min.) and

135

samples were dyed for 30 minutes. The K/S values for all the samples were evaluated using

datacolor 650 spectrophotometer. Table 5.1 show K/S mean values of the effect of each

NaOH concentration

Table 5.1: The K/S mean values of PET samples for each NaOH concentration

NaOH concentration (grams) Number of samples Mean

0 3 0.62

5 3 4.85

10 3 6.61

15 3 7.57

20 3 7.73

25 3 7.42

Figure 5.1: Effect of NaOH concentration on the K/S values of the chitosan printed PET

samples

From figure 5.1, for a given set of NaOH concentration, it is clear that by increasing the

NaOH concentration (up to 15 g/L) the K/S values increased. The K/S values slightly

increased by increasing the NaOH concentration to 20 grams and then the K/S values tended

to decrease with the increase in the NaOH concentration.

This could be due to the fact that by increasing the NaOH concentration in the pretreatment

over 15 to 20 g/L, the NaOH tends to break the open linkages on the polyester surface instead

of opening new ones which leads to the decrease in the colour strength of the samples.

Figure 5.1 also shows the standard error and the measurement of standard deviation of

sampling distribution. The results are fitting a regression model which describes the

Means and standard errors of NaOH conc. effect on K/S values of PET samples


K/S

0 5 10 15 20 25

0

2

4

6

8

136

relationship between K/S values of chitosan printed PET samples and the NaOH

concentration in the pretreatment.

Since the P-value is less than 0.05, there is a significant relationship between the K/S values

of chitosan printed PET samples and the NaOH Concentration in the pretreatment of PET

samples at the 95.0% confidence level.

The R2 value of 97.62 % indicates that the model as fitted explains 97.62 % of the variability

in K/S values of chitosan printed PET samples.

Multiple range tests were done to determine which means of levels of NaOH concentration

are significantly different from others. The Fisher's least significant difference (LSD)

procedure showed significant differences at the 95.0% confidence level between some of the

groups and no significant differences among others.


PET samples with NaOH and treated samples. By increasing the NaOH concentration in the

pretreatment of PET the difference was significant until reaching 15 g/L which is not

significantly different to 20 g/L. This again occurred by reaching 25 g/L where the K/S

values start to decrease which makes the difference between the means of 20 g/L and 25 g/L

groups not significant.

The biggest difference when comparing between treated and untreated samples, was between

0 and 20 g/L. It could be understand from the results that the pretreatment of PET samples

with NaOH would make a significant difference on the K/S values of PET samples, and that

the highest level of K/S values would be achievable with NaOH concentration between 20

g/L and 25 g/L of NaOH.


PET samples was found to be between (15-20) g/L NaOH as the 20 g/L concentration gave

the highest values of K/S levels. Results showed that there is no significant difference

between the two concentrations of 15 and 20) g/L, throughout the remaining work in this

section a concentration of 15 g/L was chosen to pre-treat PET samples as an optimum NaOH

concentration.

137

5.3.1.2. Effect of Sodium hydroxide concentration on the K/S values of 50% Cotton-

50% PET samples


NaOH according to the same procedure done on PET in part (5.3.1.1). Table 5.2 shows the

mean values of K/S for each set of NaOH concentrations three samples each.

Table 5.2: The K/S means value for blend 1 samples of each NaOH concentration

NaOH concentration Number of samples Mean

0 3 1.08

5 3 8.43

10 3 12.77

15 3 14.76

20 3 13.82

25 3 12.06


the chitosan printed 50% cotton – 50% PET samples

From figure 5.2, it is clear that the K/S values of 50% cotton – 50% PET samples increaseby

the increase of NaOH concentration (up to 15 g/L) in the pretreatment. By increasing the

NaOH concentration and as expected the K/S values tended to decrease. This is as explained

in (5.3.1.1) could be due to the fact that by increasing the NaOH concentration in the

pretreatment over 15 g/L the NaOH breaks the open linkages on the polyester surface instead

of opening new ones, this in return leads to the decrease in the colour strength of the samples.

The figure also shows the standard error for each sample.

Means and standard Errors of NaOH conc. effect on K/S values of blend1 samples


K/S

0 5 10 15 20 25

0

4

8

12

16

138

The P-value was less than 0.05, which shows that there is a significant relationship between

the K/S values of chitosan padded 50% cotton – 50% PET samples and the NaOH

Concentration in the pretreatment of Blend 1 at 95.0% confidence level. The R2 value of

98.66 % means that the model as fitted explains 98.66 % of the variability in K/S values of

chitosan printed 50% cotton – 50% PET samples.


which means that there is a significant difference between the mean of K/S values of chitosan

printed (50% cotton – 50% PET) samples from some levels of NaOH Concentration to others

at the 95.0% confidence level. To tell which NaOH Concentration is different from another,

a Fisher's least significant difference analysis (LSD) was done.

The multiple range tests showed that there is a significant difference between (50% cotton –

50% PET) samples untreated with NaOH and treated samples. It also showed nonsignificant

difference between 15 g/L and 20 g/L in the pretreatment of (50% cotton – 50% PET).

The highest level of difference was at level of NaOH concentration of 15 g/L. It could

understood from the multiple range tests that the pretreatment of (50% cotton – 50% PET)

samples with NaOH would make a significant difference on the K/S values of (50% cotton –

50% PET) samples and that the highest level of difference was at level of NaOH



(50% cotton – 50% PET) samples was found to be 15 g/L as it gave the highest K/S value

and gave the biggest difference.

5.3.1.3. Effect of sodium hydroxide concentration on the K/S values of 65% cotton-

35% PET samples


NaOH according to the same procedure done on PET samples in part (5.3.1.1).

Table 5.3 shows the mean values of K/S for each set of NaOH concentration for three

samples each.

139

Table 5.3: The means of K/S values of blend 2 samples for each NaOH concentration

NaOH concentration Number of samples Mean

0 3 1.32

5 3 14.31

10 3 16.69

15 3 18.44

20 3 18.39

25 3 16.8

Figure 5.3: Means and standard errors for the effect of NaOH concentration on the K/S

values of the chitosan printed 65% cotton – 35% PET samples

From figure 5.3, it is clear that the K/S values of 65% cotton – 35% PET samples increase by

the increase of NaOH concentration (up to 15 g/L) in the pretreatment. By increasing the

NaOH concentration further the K/S values tend to decrease. This is as explained in (5.3.1.1)

could be due to the fact that by increasing the NaOH concentration over 15 g/L in the

pretreatment, the NaOH tends to break the open linkages existing on the polyester surface

instead of opening new ones, this leads to the decrease in the colour strength of the samples.

A regression analysis showed a model describing the relationship between K/S values of

chitosan printed (65% cotton – 35% PET) samples and the NaOH Concentration in the

pretreatment.

The P-value was less than 0.05, which showed that there is a significant relationship between

the K/S values of chitosan padded 65% cotton – 35% PET samples, and the NaOH

Means and standard errors of NaOH conc. effect on K/S values of Blend2 samples


K/S

0 5 10 15 20 25

0

4

8

12

16

20

140

Concentration in the pretreatment of Blend 1 (65% cotton – 35% PET) at the 95.0%

confidence level. The R2 value of 93.08 % means that the model as fitted explains 93.08 % of

the variability in K/S values of chitosan printed 65% cotton – 35% PET samples.


which means that there are a significant differences between the mean of K/S values of

chitosan printed (65% cotton – 35% PET) samples from some levels of NaOH concentration

to others at the 95.0% confidence level.


(65% cotton – 35% PET) samples and samples treaded with NaOH. Results also showed a

nonsignificant difference between NaOH concentrations of 15 g/L and 20 g/L in the

pretreatment of (65% cotton – 35% PET). The highest level of difference was NaOH


It is concluded from the multiple range tests that the pretreatment of (65% cotton – 35% PET)

samples with NaOH makes a significant difference on the K/S values of (65% cotton – 35%

PET) samples and that the highest level of difference was at level of NaOH concentration of

15 g/L.


(65% cotton – 35% PET) samples was found to be 15 g/L as it gave the highest K/S value

and gave the biggest difference.

5.3.1.4. Multiple ANOVA analysis for the effect of NaOH concentration

A multiple ANOVA analysis was done to see if the effect of NaOH concentration in the

pretreatment would be significantly different from one type of fabric to another. The

ANOVA multiple sample comparison showed a P value of 0 which is less than 0.05 which

means that there is a significant difference between the k/S means of the three fabrics (PET,

50% PET-50% Cotton, and 65% PET- 35% Cotton) at the 95.0% confidence level.

141

Figure 5.4: Means and standard errors for the comparison between NaOH

concentration effect on different chitosan printed fabrics

Figure 5.4 shows the means and standard errors of the three fabrics under investigation (PET,

50% PET-50% cotton, and 65% PET- 35% cotton). From the figure it could be noticed that

the effect of NaOH concentration increases from PET to Blend 1 (50% PET-50% cotton) and

then increases further in Blend 2 (65% PET- 35% cotton). This could be explained by the

increase of cotton percentage in the fabric, which leads to higher concentration of chitosan

particles fixed to the fabric and an increase in the mean of K/S values.

5.3.2. Effect of chitosan fixation temperature on the K/S values of chitosan printed

textile fabrics

The following results show the effect of chitosan fixation temperature on the K/S values of

chitosan printed polyester, 50% cotton-50% PET, 65% cotton-35% PET, and cotton fabrics.

Fabrics were treated with 15 gm/L of sodium hydroxide at 80 °C for 30 minutes in L:R 1: 20.

After exhaustion bath, samples were washed with distilled water and 3% acetic acid, dried,

printed with a printing paste containing

20 gm/Kg Chitosan

3% Acetic acid

Y Water

____________________________

1000 g.

Means and standard errors

PET Blend 1 Blend 2

6

8

10

12

14

16

18M

ean

142

Samples were then cured at (140, 160, 180, and up to 220° C in the case of PET) for 4

minutes, after that samples were dyed with acid dye Sandolan Blue E-2GL 200%, air dried

and then the colour strength was evaluated.

5.3.2.1. Effect of chitosan fixation temperature on the K/S values of chitosan printed

PET samples

As mentioned in part (5.3.2) PET samples pretreated with NaOH solution of 15 g/L were

printed with chitosan and thermally fixed at (140, 160, 180, 200 and 220 °C) to study the

effect of fixation temperature on the K/S values of chitosan printed PET samples.

Table 5.4 shows the mean K/S values for each set of temperature for three samples at each

fixation temperature.

Table 5.4: The K/S means values of chitosan printed PET samples for each fixation

temperature

Temperature Number of samples Mean

0 3 0.62

140 3 7.05

160 3 8.27

180 3 8.85

200 3 13.70

220 3 14.68

Figure 5.5: Means and standard error for the effect of fixation temperature on the K/S

values of the chitosan printed PET samples

Means and standard errors of fixation temp. effect on K/S values of PET samples

temp (°C)

K/S

0 140 160 180 200 220

0

3

6

9

12

15

143

From figure 5.5, for a given set of fixation temperature, it could be seen that the K/S values

of chitosan printed PET samples slightly increased by the increase of fixation temperature up

to 180 °C.

By increasing the fixation temperature of chitosan printed PET samples to 200°C the K/S

values increased showing a huge change in K/S values of PET samples. By increasing the

fixation temperature further to 220 °C, a slight increase in the K/S values is noticed with a

slight yellowness caused by chitosan deposited on the surface of PET samples and by PET

samples being affected by the high temperature. The figure also shows the standard error for

each sample.


values of chitosan printed PET samples and the fixation temperature.

The P-value in the regression analysis is 0 (less than 0.05) which shows that there is a

significant relationship between the K/S values of chitosan padded PET samples and the

fixation temperature of PET samples at the 95.0% confidence level.


K/S values of chitosan printed PET samples.


PET samples and treated samples with chitosan at any set of fixation temperature.

Results also showed that by increasing the fixation temperature from 160 °C to 180 °C for

PET samples the difference was not significant, and that by increasing the fixation

temperature from 180 °C to 220 °C, PET samples showed a significant difference.

The highest level of difference was at temperature of 220 °C but this could be due to the

chitosan deposited on the surface of PET samples. It is concluded from the multiple range

tests that the pretreatment of PET samples with chitosan would make a significant difference

on the K/S values of PET samples and that the highest level of difference was at temperature

of 220 °C.

As a conclusion the optimum fixation temperature of chitosan printed PET samples was

found to be 200 °C as it gave the highest values of K/S levels and made the biggest level of

difference between treated and untreated samples after excluding the 220 °C as the latest

caused the yellowness of the samples.

144

5.3.2.2. Effect of fixation temperature on the K/S values of chitosan printed 50%

cotton- 50% PET samples

Samples of 50% cotton - 50% PET (Blend 1) where pretreated with NaOH solution of 15 g/L

, then were printed with chitosan and thermally fixed at (140, 160, 180, and 200 °C), to study

the effect of fixation temperature on the K/S values of chitosan printed 50% cotton - 50%

PET samples.

Table 5.5 shows the mean K/S values of each set of fixation temperature for three samples

each.

Table 5.5: K/S mean values of chitosan printed blend 1 samples for each fixation

temperature


0 3 1.08

140 3 8.63

160 3 13.76

180 3 14.4

200 3 15.89




by the increase of fixation temperature of chitosan printed samples. The highest K/S values

was at 180 °C, by increasing the fixation temperature to 200 °C, samples colour changed to

yellow because of the existence of cotton percentage in the blend, which affected the overall

colour and would give false results when evaluating the colour strength. The figure also

shows the standard error for each sample.

Temperature (°C)

K/S


0 140 160 180 200

0

3

6

9

12

15

18

145

By doing the regression analysis, a regression model describing the relationship between K/S

values of chitosan printed (50% cotton – 50% PET) samples and the fixation temperature of

the printed samples was obtained, see appendix B.


K/S values of chitosan printed 50% cotton – 50% PET samples and the fixation temperature

at the 95.0% confidence level. The R2 value of 95.07 % means that the model as fitted

explains 95.07 % of the variability in K/S values of chitosan printed 50% cotton – 50% PET

samples.

To tell which fixation temperature is different from another a Fisher's least significant

difference analysis (LSD) where done.

Results showed that there is a significant difference between non treated (50% cotton – 50%

PET) samples and samples treated with chitosan at any temperature. By increasing the

fixation temperature from 140 °C to 160 °C and from 180 °C to 200 °C the difference was

significant. This behaviour changes by reaching fixation temperature of 180 °C where K/S

values were found to be slightly increasing, hence making a non-significant difference

between the means of sampled fixed at 160 °C and samples fixed at 180 °C. The highest level

of difference occurred when the temperature was 180 and 200 °C.

It is obvious from the results ( see appendix B), that the fixation of chitosan on (50% cotton –

50% PET) samples would make a significant difference on the K/S values of the samples and

that the highest level of difference was at fixation temperature of 180 to 200 °C.

As a conclusion the optimum fixation temperature for the chitosan printed (50% cotton –

50% PET) samples was found to be 180 °C although the highest K/S value was obtained at

200 °C fixation temperature, this to avoid yellowing of the fabrics.

5.3.2.3. Effect of fixation temperature on the K/S values of chitosan printed 65%

Cotton- 35% PET samples

Samples of 65% cotton - 35% PET (Blend 2) were pretreated with NaOH solution of 15 g/L ,

then weere printed with chitosan and thermally fixed at (140, 160, 180, and 200 °C) to study

the effect of fixation temperature on the K/S values of chitosan printed 65% cotton - 35%

PET samples.

Table 5.6 shows the mean K/S values of each set of fixation temperatures.

146

Table 5.6: K/S mean values of chitosan printed blend 2 samples for each fixation

temperature

Temperature Number of samples K/S mean value

0 3 1.32

140 3 9.33

160 3 17.26

180 3 20.20

200 3 20.92




by increasing the fixation temperature of chitosan printed samples. The Highest K/S values

were at 180 °C, after that by increasing the fixation temperature to 200 °C yellowness issue

occurred as aforementioned. Figure 5.7 also shows the standard error for each sample.

The regression analysis showed a regression model describing the relationship between K/S

values of chitosan printed (65% cotton – 35% PET) samples and the fixation temperature of

the printed samples.


K/S values of chitosan printed 65% cotton – 35% PET samples and the fixation temperature

of 65% cotton – 35% PET samples at the 95.0% confidence level.

Temperature (°C)

K/S


0 140 160 180 200

0

4

8

12

16

20

24

147


K/S values of chitosan printed 65% cotton – 35% PET samples


(65% cotton – 35% PET) samples and chitosan treated samples at any temperature.

Increasing the fixation temperature from 140 °C to 200 °C gave a significant difference in

K/S values. The highest level of difference occurred at fixation temperature from 80 to 200

°C.

It could understood from the multiple range tests that the fixation of chitosan on (65% cotton

– 35% PET) samples would make a significant difference on the K/S values of (65% cotton –

35% PET) samples and that the highest level of difference was at fixation temperature of 180

to 200 °C.

As a conclusion the optimum fixation temperature for the chitosan printed (65% cotton –

35% PET) samples was found to be 180 °C.

5.3.2.4. Effect of fixation temperature on the K/S values of cotton samples

Cotton samples were printed with chitosan solution and thermally fixed at (140, 160, 180,

200 °C), this was to study the effect of fixation temperature on the K/S values of chitosan

printed cotton samples.

Table 5.7 show the mean of K/S values for each set of fixation temperatures for three samples

each.

Table 5.7: The mean values of K/S for cotton samples of each fixation temperature


0 3 1.53

140 3 13.13

160 3 19.61

180 3 21.76

200 3 24.44

148


values of the chitosan printed cotton samples

From figure 5.8, it is clear that the K/S values of cotton samples increased by the increase of

fixation temperature of chitosan printed samples. The highest K/S values were at 180 °C.

By increasing the fixation temperature to 200 °C, yellowness of fabric occurred, this affected

the overall colour and gave false spectrophotometer readings. Figure 5.8 also shows the

standard error for the three samples of each fixation temperature as explained previously.

The regression analysis gave a regression model that describes the relationship between K/S

values of chitosan printed cotton samples and the fixation temperature.

The P-value in the ANOVA table is less than 0.05, which shows that there is a significant

relationship between the K/S values of chitosan printed samples and the fixation temperature

of cotton samples at the 95.0% confidence level.

The R2 value of 98 %means that the model as fitted explains 98 % of the variability in K/S

values of chitosan printed cotton samples.


cotton samples and chitosan printed samples at any fixation temperature. By increasing the

fixation temperature from 140 °C to 200 °C the difference was significant. The highest level

of difference occurred at fixation temperature of 180 to 200 °C.

It could be understood from the multiple range tests that the fixation of chitosan cotton

samples would make a significant difference on the K/S values of cotton samples and that the

Means and standard errors of fixation temp. effect on K/S of cotton samples

Temperature (°C)

K/S

0 140 160 180 200

0

5

10

15

20

25

149

highest level of difference was at fixation temperature between 180 - 200 °C. Although

fixation temperature of 200 °C gave the highest K/S results but it was avoided to avoid the

yellowness occurring in the fabric by such higher temperature. That is why a fixation

temperature of 180 °C was considered as the optimum fixation temperature for chitosan

printed cotton samples.

It is concluded that the optimum fixation temperature for the chitosan printed cotton samples

was found to be 180 °C.

5.3.2.5. Multiple ANOVA analysis for the effect of fixation temperature of K/S for

the textile samples

A multiple ANOVA analysis was done to see if the effect of fixation temperature would be


comparison showed a P value of 0 which is less than 0.05, meaning that the K/S showed a

significant difference K/S means for the studied fabrics (PET, 50% PET-50% cotton, , 65%

PET- 35% cotton and cotton) at the 95.0% confidence level.

Figure 5.9 Means and standard errors for the comparison between fixation

temperatures effect on different chitosan printed fabrics

Figure 5.9 show the difference between the K/S means of (PET, 50% PET-50% Cotton, and

65% PET- 35% Cotton, and cotton) fabrics at the 95.0% confidence level. From the figure it

could be noticed that the effect of fixation temperature increases from PET to Blend 1 (50%

PET-50% Cotton) and then increases again in Blend 2 (65% PET- 35% Cotton) then

increases further in cotton.



9

11

13

15

17

19

21

Mean

150

This could be explained by the increase of the cotton percentage in the fabric, which leads to

higher concentration of chitosan particles fixed to the fabric and higher affinity to dye stuff

which leads to an increase in the mean of K/S values.

5.3.3. Effect of chitosan fixation time on chitosan printed textile samples

The following results show the effect of chitosan fixation time on the K/S values of chitosan

printed polyester, 50% cotton-50% PET, 65% cotton-35% PET, and cotton fabrics.


After exhaustion bath, samples were washed with distilled water and 3% acetic acid, dried,

printed with a printing paste containing:

20 gm/Kg Chitosan

3% Acetic acid

Y Water

____________________________

1000 g.

Sample were then cured at 180 ° C except for PET samples which were cured at 200° C for

(1, 2, 3, and 4 minutes), after that samples were dyed with acid dye Sandolan Blue E-2GL

200%, air dried and then the colour strength was evaluated.

5.3.3.1. Effect of fixation time on the K/S values of chitosan printed PET samples


printed with chitosan printing paste and were thermally fixed at 200 °C for (1, 2, 3, and 4

minutes) to study the effect of fixation time on the K/S values of chitosan printed PET

samples.


Table 5.8: The K/S means values of PET samples for each fixation time

Time Number of samples K/S Mean values

0 3 0.62

1 3 8.99

2 3 9.41

3 3 12.86

4 3 13.27

151


of the chitosan printed PET samples


chitosan printed PET samples increased by the increase of fixation time to 3 minutes. By

increasing the fixation time of chitosan printed PET samples to 4 minutes, the K/S values

slightly increased but with a slightly yellowness of the samples caused by the chitosan film

depositing on the surface of PET samples changing their colour to yellow. Figure 5.10 also

shows the standard error for each sample as well.


values of chitosan printed PET samples and the fixation time. The P-value in the regression

analysis is less than 0.05, which shows that there is a significant relationship between the K/S

values of chitosan printed PET samples and the fixation time of at the 95.0% confidence

level.


K/S values of chitosan printed PET samples

The ANOVA analysis showed that the P-value is 0 which is less than 0.05. This means that

there is a significant difference between the mean of K/S values of chitosan printed PET

samples from one set of fixation time to anther at the 95.0% confidence level. LSD analysis

was done to determine which fixation time is significantly different from another.


PET samples and printed samples with chitosan at any set of fixation time.

Time (minutes)

K/S

Means and standard errors of fixation time effect on K/S values of PET samples

0 1 2 3 4

0

3

6

9

12

15

152

It is concluded from the results that by increasing the fixation time from 1 to 2 minutes for

treating PET samples, the difference was not significant, by increasing the fixation time from

2 to 3 minutes, PET samples showed a significant difference, and by increasing the fixation

time from 3 to 4 minutes, samples showed an insignificant difference again. Results of

Multiple range test, regression model, and Anova table are thoroughly listed in appendix B.

The highest level of difference was at a fixation time between 3 and 4 minutes but with no

significant difference between these two sets of fixation time. It could be understood from the

multiple range tests that the pretreatment of PET samples with chitosan would make a

significant difference on the K/S values of PET samples when fixed at any fixation time

when compared to untreated and that the highest level of difference was at fixation time

between 3-4 minutes.

As a conclusion the optimum fixation time for chitosan printed PET samples was found to be

between 3 and 4 minutes. This gave the highest values of K/S levels and made the biggest

level of difference between treated and untreated samples. In the following work a fixation

time of 3 minutes was chosen to be the optimum fixation time for chitosan printed PET

samples, as there was no significant difference in the effect on K/S values of treated samples

for 3 and treated samples for 4 minutes.


As mentioned in part (5.3.3) 50% cotton – 50% PET samples pretreated with NaOH solution

of 15 g/L were printed with chitosan and thermally fixed at 180 °C for (1, 2, 3, and 4

minutes) to study the effect of fixation time on the K/S values of chitosan printed 50% cotton

– 50% PET samples, table 5.9 shows the mean K/S values of each set of time for three.

Table 5.9: The K/S means values of 50% cotton – 50% PET samples for each fixation

time three samples each


0 3 1.08

1 3 9.73

2 3 11.21

3 3 12.36

4 3 14.73

153




chitosan printed 50% cotton – 50% PET samples increased by the increase of fixation time. It

is worth mentioning that when fixation time was 4 minutes the 50% cotton – 50% PET

samples showed slight yellowness, this yellowness could be a result of some factors, i.e.

higher percentage of chitosan deposited on the fabric surface, existence of higher percentage

of cotton fibres which tend to change their colour in the blended fabric due to their exposure

to the fixation temperature for a longer period of time. Figure 5.11 also shows the standard

error for each sample as explained previously.

K/S results are fitting a regression model which describes the relationship between K/S

values of chitosan padded 50% cotton – 50% PET samples and the fixation time. The results

showed P-value in the regression analysis was less than 0.05, this showed that there is a

significant relationship between the K/S values of chitosan padded 50% cotton – 50% PET

samples and the fixation time of PET samples at the 95.0% confidence level.


K/S values of chitosan printed 50% cotton – 50% PET samples.

Fisher's least significant difference analysis was done to determine which fixation time is

significantly different from another.


50% cotton – 50% PET samples and printed samples with chitosan at any set of fixation time.

Time (minutes)

K/S

Means and standard errors of fixation time effect on K/S of blend1 samples

0 1 2 3 4

0

3

6

9

12

15

154

It also showed that by increasing the fixation time from 1 to 2 minutes, from 2 to 3 minutes

and from 3 to 4 minutes for 50% cotton – 50% PET, samples showed a significant difference.

The highest level of difference was at fixation time of 4 minutes but this could be a results of

the fabric changing its colour to yellow which in return might have given an inaccurate K/S

value as explained previously. It could concluded from the multiple range tests that the

pretreatment of 50% cotton – 50% PET samples with chitosan would make a significant

difference on the K/S values of PET samples when fixed and that the highest level of

difference was at fixation time between 3-4 minutes.

As a conclusion the optimum fixation time for chitosan printed 50% cotton – 50% PET

samples was found to be 3 minutes. As it gave the highest values of K/S levels and made the

biggest level of difference between treated and treated samples. Fixation time for 4 minutes

was excluded for yellowness issue explained previously.


65% cotton – 35% PET samples pretreated with NaOH solution of 15 g/L were printed with

chitosan and thermally fixed at 180 °C for (1, 2, 3, and 4 minutes) to study the effect of

fixation time on the K/S values of chitosan printed 65% cotton – 35% PET samples, table

5.10 shows the mean K/S values of each set of time for three samples each.


time


0 3 1.32

1 3 10.6

2 3 11.74

3 3 13.78

4 3 18.82

155




chitosan printed 65% cotton – 35% PET samples increased by the increase of fixation time.

Worth mentioning again that in fixation time 4 minutes the 65% cotton – 35% samples

showed slight yellowness as explained previously. The figure also shows the standard error

;measurement of standard deviation of sampling distribution (Hanneman et al., 2012) for

each sample as well.


values of chitosan printed 65% cotton – 35% PET samples and the fixation time (see

appendix B).





K/S values of chitosan printed 65% cotton – 35% PET samples. This could be seen in the

plot of the fitted model curve listed in appendix B.

The LSD analysis was done to determine which fixation time is significantly different from

another.

Means and standard errors of fixation time effect on K/S of blend2 samples

Time (minutes)

K/S

0 1 2 3 4

0

4

8

12

16

20

156


65% cotton – 35% PET samples and treated samples with chitosan at any set of fixation time.

It also showed that by increasing the fixation time from 1 to 2 minutes for 65% cotton – 35%

PET samples, the difference in K/S was not significant.

By increasing the fixation time from 2 to 3 minutes and from 3 to 4 minutes, 65% cotton –

35% PET samples showed a significant difference again.

The highest level of difference was at fixation time of 4 minutes, but fixation time of 3-4

minutes was concluded to be the optimum fixation conditions, this was to avoid turning the

colour of the samples into yellow by exposing the sample to higher fixation time, and because

there was no significant difference in K/S mean values of samples treated for three and four

minutes.

As a conclusion the optimum fixation time for chitosan printed 65% cotton – 35% PET

samples was found to be 3 minutes. As it gave the highest values of K/S levels and made the

biggest level of difference between untreated and treated samples.

5.3.3.4. Effect of fixation time on the K/S values of cotton samples

Cotton samples were printed with chitosan and thermally fixed at 180 °C for (1, 2, 3, and 4

minutes) to study the effect of fixation time on the K/S values of chitosan printed cotton

samples. Table 5.11 shows the mean K/S values of each set of time for three samples each.

Table 5.11: The K/S means values of cotton samples for each fixation time


0 3 1.53

1 3 12.68

2 3 13.63

3 3 15.89

4 3 19.97

157


of the chitosan printed cotton samples


chitosan printed cotton samples increased by the increase of fixation time to 3 minutes.

By increasing the fixation time of chitosan printed cotton samples to 4 minutes, the K/S

values increased but with the expected dark yellow shade. The figure also shows the standard

error for each sample.

The relationship between K/S values of chitosan padded cotton samples and the fixation

temperature is described in the fitted model equation (see appendix B).


relationship between the K/S values of chitosan printed cotton samples and the fixation time

of cotton samples at the 95.0% confidence level.


K/S values of chitosan printed cotton samples.


cotton samples and printed samples with chitosan at any set of fixation time. It also showed

that by increasing the fixation time from 1 to 2 minutes for cotton samples, the difference in

K/S mean values was not significant.

It could understood from the multiple range tests that the pretreatment of cotton samples with

chitosan would make a significant difference on the K/S values of cotton samples, and that

Time (minutes)

K/S

Means and standard errors of fixation time effect on K/S of cotton samples

0 1 2 3 4

0

4

8

12

16

20

24

158

the highest level of difference was at fixation time between 3-4 minutes. As a conclusion the

optimum fixation time for chitosan padded cotton samples was found to be 3 minutes.

5.3.3.5. Multiple ANOVA analysis for the effect of fixation time on K/S values of

treated samples

A multiple ANOVA analysis was done to see if the effect of fixation time would be


comparison showed a P value of 0 which is less than 0.05. This means that there is a

significant difference between the K/S mean value of the fabrics under investigation; (PET,

50% PET-50% cotton, 65% PET- 35% cotton and cotton) at the 95.0% confidence level.

Figure 5.14: Means and standard errors for the comparison between fixation time effect

on the different fabrics

Figure 5.14 show the difference between the means for K/S values of the 4 fabrics (PET, 50%

PET-50% Cotton, and 65% PET- 35% Cotton, and cotton) at the 95.0% confidence level. It

could be noticed that the effect of fixation time slightly increases from PET to Blend 1 (50%

PET-50% Cotton), then increases again in Blend 2 (65% PET- 35% Cotton), then increases

further in cotton.

This could be explained by the increase of cotton percentage in the fabric, which leads to

higher concentration of chitosan particles fixed to higher percentage of cotton existing in the

fabric. This causes higher affinity to dye stuff which leads to an increase in the mean of K/S

values.



10

12

14

16

18

Mean

159

The small increase in K/S means between PET and Blend 1 (50% PET-50%) is due the

higher fixation temperature that PET samples were fixed at, which lead to higher K/S values


5.3.4. Effect of chitosan concentration on the K/S values of chitosan printed textile

fabrics

The following results show the effect of chitosan concentration in the printing paste on the

K/S values of polyester, 50% cotton-50% PET, 65% cotton-35% PET, and cotton fabrics.

Fabrics were treated with 15 gm/L of sodium hydroxide (except for cotton) at 80 °C for 30

minutes in L:R 1: 20. After exhaust bath, samples were washed with distilled water and 3%

acetic acid, dried.

Samples were then printed with a printing paste containing:

X gm/Kg Chitosan

3% Acetic acid

Y Water

___________________________

1000 g.

Chitosan concentrations used were (5, 10, 15, and 20 gm/Kg). Samples were then cured at

180 °C for cotton and blend 1 and blend 2 for 3 minutes and in the case of PET, samples were

treated for 200 °C for 3 minutes. After that; samples were dyed with Sandolan Blue E-2GL

200% acid dye, air dried and then evaluated for the colour strength.

5.3.4.1. Effect of chitosan concentration on the K/S values of PET samples


printed with a printing paste with chitosan concentration of (5, 10, 15, and 20 gm/L) and 3%

acetic acid, then thermally fixed at 200 °C for 3 minutes.

Samples were then dyed with acid dye, air dried and evaluated for colour strength to study

the effect of chitosan concentration on the K/S values of chitosan printed PET samples, table

5.12 shows the mean K/S values of each set of time for three samples each.

160

Table 5.12: The K/S mean values of PET samples for each chitosan concentration


0 3 0.62

5 3 5.68

10 3 7.21

15 3 8.01

20 3 12.06


K/S values of the chitosan padded PET samples


values of chitosan printed PET samples increased by the increase of chitosan concentration.

The figure also shows the standard error for each sample as well.


values of chitosan padded PET samples and the chitosan concentration (see appendix B).


relationship between the K/S values of chitosan printed PET samples and the chitosan

concentration at the 95.0% confidence level.


K/S values of chitosan printed PET samples.

The ANOVA analysis showed that the P-value is 0 which is less than 0.05. This means that

there is a significant difference between the mean values of K/S values of chitosan printed

PET samples from one chitosan concentration to another at the 95.0% confidence level. LSD

Means and standard errors of chitosan conc. effect on K/S of cotton samples


K/S

0 5 10 15 20

0

3

6

9

12

15

161

(Fisher's least significant difference analysis) was done to determine which chitosan

concentration is significantly different from another.


PET samples and printed samples with chitosan at any concentration.

The highest level of difference was at chitosan concentration 20 g/L. Increasing the chitosan

concentration from 10 to 15 grams showed insignificant difference between the two levels.

It could understood from the multiple range tests that the pretreatment of PET samples with

chitosan would make a significant difference on the K/S values of PET samples at any

chitosan concentration and the highest K/S values could be achieved using 20 g/L of chitosan

concentration.

As a conclusion the optimum chitosan concentration for printed PET samples was found to be

20 grams. This concentration gave the highest value of K/S and made the biggest level of

difference between untreated and printed samples with chitosan.


samples

As mentioned in part (5.3.4) 50% cotton- 50% PET pretreated with NaOH solution of 15 g/L

were printed with a printing paste with chitosan concentration of (5, 10, 15, and 20 grams)

and 3% acetic acid, then thermally fixed at 180 °C for 3 minutes. This was to study the effect

of chitosan concentration on the K/S values of chitosan printed 50% cotton- 50% PET

pretreated samples. Samples were then dyed with acid dye, air dried and evaluated for the

colour strength.


Table 5.13: The mean values of K/S of 50% cotton- 50% PET samples for each chitosan


0 3 1.08

5 3 6.27

10 3 7.32

15 3 8.7

20 3 12.17

162


of the chitosan printed 50% cotton- 50% PET samples


values of chitosan printed 50% cotton- 50% PET samples (Blend 1)increased by the increase

of chitosan concentration. The figure also shows the standard error for each sample as well.


values of chitosan printed 50% cotton- 50% PET samples and the chitosan concentration (see

appendix B).


relationship between the K/S values of chitosan printed 50% cotton- 50% PET samples and



K/S values of chitosan printed 50% cotton- 50% PET samples.

LSD (Fisher's least significant difference analysis) was done to determine which chitosan




The highest level of difference was at a chitosan concentration 20 g/L. It could understood

from the multiple range tests that the pretreatment of the samples with chitosan would make a


K/S

Means and standard errors of chitosan conc. effect on K/S of Blend1 samples

0 5 10 15 20

0

3

6

9

12

15

163

significant difference on the K/S values of 50% cotton- 50% PET samples at any chitosan

concentration and the highest K/S values could be achieved using 20 g/L of chitosan

concentration.

As a conclusion the optimum chitosan concentration for printed 50% cotton- 50% PET

samples was found to be 20 g/L, it gave the highest values of K/S levels and made the biggest

level of difference between untreated and treated samples with chitosan.


samples

As mentioned in part (5.3.4) 65% Cotton- 35% PET samples pretreated with NaOH solution

of 15 g/L were printed with a printing paste with chitosan concentration of (5, 10, 15, and 20

grams) and 3% acetic acid, thermally fixed at 180 °C for 3 minutes.

Samples were dyed with acid dye, air dried and then evaluated for colour strength. This was

to study the effect of chitosan concentration on the K/S values of chitosan printed 65%

cotton- 35% PET pretreated samples. Table 5.14 shows the mean K/S values of each set of

time for three samples each.

Table 5.14 The K/S mean values of 65% cotton- 35% PET samples for each chitosan

concentration

Chitosan Concentration Number of samples K/S mean values

0 3 1.32

5 3 6.74

10 3 8.3

15 3 9.58

20 3 14.05

164


of the chitosan padded 65% cotton- 35% PET samples


values of chitosan printed 65% cotton- 35% PET samples (Blend 1) increased by the increase

of chitosan concentration. The figure also shows the standard error for each sample.


values of chitosan printed 65% cotton- 35% PET samples and the chitosan concentration (see

appendix B).


relationship between the K/S values of chitosan printed 65% cotton- 35% PET samples and



K/S values of chitosan printed 65% cotton- 35% PET samples.





The highest level of difference was at a chitosan concentration 20 grams. It could be

understood from the results that the pretreatment of 65% cotton- 35% PET samples with

chitosan would make a significant difference on the K/S values of 65% cotton- 35% PET

Means and standard errors of chitosan conc. effect on K/S of Blend 2 samples


K/S

0 5 10 15 20

0

3

6

9

12

15

165

samples at any chitosan concentration, and the highest K/S values could be achieved using 20

grams of chitosan concentration.

As a conclusion the optimum chitosan concentration for printed 65% cotton- 35% PET

samples was found to be 20 g/L. As it gave the highest value of K/S and made the biggest

level of difference between untreated and treated samples with chitosan.

5.3.4.4. Effect of chitosan concentration on the K/S values of cotton samples

As mentioned in part (5.3.4), cotton samples were printed with a printing paste containing

chitosan concentration of (5, 10, 15, and 20 grams) and 3% acetic acid, thermally fixed at 180

°C for 3 minutes. Samples were then dyed with acid dye, air dried and evaluated for colour

strength to study the effect of chitosan concentration on the K/S values of chitosan printed

cotton pretreated samples


Table 5.15 The K/S mean values of cotton samples for each chitosan concentration

Chitosan Concentration Number of samples K/S mean values

0 3 1.53

5 3 8.68

10 3 9.96

15 3 11.55

20 3 16.44


of the chitosan printed cotton samples

Means ans standard errors of chitosan conc. effect on K/s of cotton samples


K/S

0 5 10 15 20

0

3

6

9

12

15

18

166


values of chitosan printed cotton samples increased by the increase of chitosan concentration.

The figure also shows the standard error for each sample


values of chitosan printed cotton samples and the chitosan concentration (see appendix B).


relationship between the K/S values of chitosan printed cotton samples and the chitosan

concentration at the 95.0% confidence level.


K/S values of chitosan printed cotton samples.




cotton samples and treated samples with chitosan at any concentration.

Results showed that the highest level of difference was at chitosan concentration of 20 grams.

It could understood from the multiple range tests that printing cotton samples with chitosan

would make a significant difference on the K/S values of cotton samples at any chitosan

concentration and the highest K/S values could be achieved using 20 g/L of chitosan

concentration.

As a conclusion the optimum chitosan concentration for printed cotton samples was found to

be 20 grams, as it gave the highest value of K/S and made the biggest level of difference

between untreated and treated samples with chitosan.

5.3.4.5. Multiple ANOVA analysis for the effect of chitosan concentration

A multiple ANOVA analysis was done to see if the effect of chitosan concentration would

show a significant difference from one type of fabric to another. The ANOVA multiple

sample comparison showed a P value of 0.02 which is less than 0.05 which means that there

is a significant difference between the mean values of K/S of the fabrics under investigation;

(PET, 50% PET-50% cotton, , 65% PET- 35% cotton and cotton) at the 95.0% confidence

level.

167

Figure 5.19 Means and standard errors for the comparison between chitosan

concentration effects on different fabrics

Figure 5.19 shows the difference between the means for K/S values of the studied fabrics

(PET, 50% PET-50% Cotton, and 65% PET- 35% Cotton, and cotton) and the standard errors

for each fabric at the 95.0% confidence level.

From the figure it could be noticed that the effect of chitosan concentration on K/S values

slightly increases from PET to blend 1 (50% PET-50% Cotton), significantly increases in

blend 2 (65% PET- 35% cotton) and then increases further in cotton.

This could be explained by the increase of cotton percentage in the fabric. This lead to higher

concentration of chitosan particles fixed to the higher percentage of cotton existing in the

fabric. This means higher affinity to dye stuff which leads to an increase in the mean of K/S

values.

The small increase in K/S means between PET and Blend 1 (50% cotton-50% PET) is due the

higher fixation temperature that PET samples were fixed at, which lead to higher K/S values


5.4. Samples evaluation

5.4.1. Colour fastness evaluation

5.4.1.1. Colour fastness to crocking

As explained in Chapter three the colour fastness for crocking was done according to

(BS.EN.ISO-105-X12:2002). Results are shown in table 5.16.




7.5

8.5

9.5

10.5

11.5

12.5

13.5M

ean

168

Table 5.16: Fastness to dry and wet crocking of chitosan printed samples

Samples Crocking

Dry Wet

Polyester

NaoH concentration

Untreated 4-5 3-4

5 gm NaoH 4-5 1-2

10 gm NaoH 3-4 1

15 gm NaoH 3-4 1

20 gm NaoH 4-5 1-2

25 gm NaoH 4-5 2

Temperature

140°C 3 1

160°C 4 1

180°C 4 1-2

Time

1 min. 3-4 1-2

2 min. 4 1-2

3 min. 4-5 4

4 min. 4-5 3-4

Ca Concentration

5 gm. 4-5 2-3

10 gm. 4 1-2

15 gm. 4 1-2

20 gm. 3 1-2

Cotton

Temperature

140°C 4-5 1-2

160°C 4-5 2-3

180°C 4-5 3

Time

1 min. 4-5 2-3

2 min. 4-5 3

3 min. 4-5 3-4

4 min. 4-5 4-5

Ca Concentration

5 gm. 4-5 4-5

10 gm. 4-5 3-4

15 gm. 4-5 3

20 gm. 4-5 2-3

50% cotton-

50% Polyester

NaoH concentration

Untreated 4-5 4

5 gm NaoH 4-5 3-4

10 gm NaoH 4-5 3

15 gm NaoH 4-5 2

20 gm NaoH 4-5 2-3

25 gm NaoH 4-5 3-4

Temperature

140°C 4-5 1

160°C 4 1-2

180°C 4-5 1

Time

1 min. 4-5 2

2 min. 4-5 1-2

3 min. 4-5 1-2

4 min. 4-5 1-2

Ca Concentration

5 gm. 4 1-2

10 gm. 4 1-2

15 gm. 4 1-2

20 gm. 4 1

65% cotton- NaoH concentration Untreated 4 2

169

35% Polyester

5 gm NaoH 4-5 1

10 gm NaoH 4 1-2

15 gm NaoH 4 1-2

20 gm NaoH 4 1

25 gm NaoH 4 1

Temperature

140°C 3 1

160°C 3-4 1

180°C 4-5 2

Time

1 min. 4 1-2

2 min. 3-4 1

3 min. 3-4 1-2

4 min. 4 1-2

Ca Concentration

5 gm. 5 2

10 gm. 4-5 1-2

15 gm. 5 1-2

20 gm. 4-5 1-2

From the results it could be seen that the chitosan printed samples possessed a good to very

good fastness to dry crocking but showed medium to poor fastness properties for wet

crocking. This could be due to the fact that the chitosan is deposited on the surface of the

fabric which is forming a film on the surface like several types of textile printing. This in

return causes the film to be easier to rub off when subjected to wet crocking. It has to be

mentioned that wet textiles usually give lower results of crocking than dry fabrics.

5.4.1.2. Colour fastness to domestic and commercial laundering

As explained in Chapter three a domestic washing test (BS-EN-ISO:6330, 2012) was done on

five chitosan printed, acid dyed samples with optimum conditions of each material (cotton,

polyester, 50% cotton/ 50% polyester blends, and 65% cotton/35% polyester blends).

Results were compared to dyed samples with zero chitosan treatment. Samples were

evaluated according to grey scale rating the change in colour. The results showed very good

to excellent fastness to domestic washing as shown in table 5.17.

170

Table 5.17: Fastness properties of chitosan printed fabrics for domestic and commercial

laundering

Samples

Washing

First wash Second wash Third wash Fourth wash Fifth wash

Polyester 5 5 4-5 4-5 4-5

50% cotton-

50% Polyester 5 4-5 4-5 4 4

65% cotton-

35% Polyester 4-5 4-5 4 4-5 4

Cotton 4-5 4-5 4 4 4

5.4.1.3. Colour fastness to perspiration

Colour fastness to perspiration was done to measure how fast the chitosan prints are for

human sweat. In this tests chitosan printed samples dyed with acid dye were evaluated for

colour fastness for perspiration, Samples were evaluated according to grey scale rating for

staining (BS.EN.ISO:105-E04, 2009).

Results showed moderate to poor fastness to perspiration as shown in table 5.18.

171

Table 5.18: fastness properties of chitosan printed fabrics for perspiration

Samples

Acid Alkali

Wool Acrylic PET Nylon Cotton Acetate Wool Acrylic PET Nylon Cotton Acetate

Polyester

NaoH

concentration

Untreated 2 2 3-4 1-2 2-3 2 1-2 3-4 2-3 1 1 1

5 gm NaoH 2 2 3-4 1-2 2-3 2-3 1-2 3-4 2-3 1 1-2 1

10 gm NaoH 2 2 3 1 2 2 1-2 3-4 2 1 1 1

15 gm NaoH 2 2-3 3 1-2 2-3 2-3 2 3 2-3 1-2 1-2 1-2

20 gm NaoH 2 2-3 4 1-2 2-3 2-3 1-2 3 2-3 1 1-2 1-2

25 gm NaoH 2 2 3-4 1-2 2-3 2 1-2 3-4 2-3 1 1 1

Temperature

120°C 2 2-3 3 1-2 2-3 2-3 1-2 3-4 2-3 1 1-2 1-2

140°C 2 2-3 3-4 1-2 2-3 2-3 1-2 3 2-3 1 1-2 1-2

160°C 2 2 3 1-2 2-3 2-3 1-2 3 3 1 1-2 1-2

180°C 2 2-3 3-4 1-2 2-3 2-3 2 3 2-3 1 1-2 1-2

Time

1 min. 2 2-3 3 1-2 2-3 2-3 2 3-4 2-3 1 1-2 1-2

2 min. 2 2-3 3-4 1-2 2-3 2-3 2 3 2-3 1 1-2 2

3 min. 2 2-3 3 1-2 2-3 2-3 2 3-4 2-3 1 1-2 1-2

4 min. 1-2 1-2 2-3 1 1-2 1-2 1 2-3 2 1 1 1

Ca 5 gm. 2 2 3-4 1-2 2-3 2 1-2 3-4 2 1 1-2 1-2

172

Concentration 10 gm. 2 2 3 1-2 2-3 2-3 2 3-4 2 1-2 2 2

15 gm. 2 2 3-4 1-2 2-3 2-3 2 3-4 2-3 1 2 2

20 gm. 2 2 3-4 1 2-3 2-3 2 3-4 2-3 1 1-2 1-2

50%

cotton-

50%

Polyester

NaoH

concentration

Untreated 2 2 3-4 1-2 2-3 2-3 1-2 3-4 2-3 1 1-2 1

5 gm NaoH 2 2 3-4 1-2 2 2 1-2 3-4 2-3 1 1-2 1

10 gm NaoH 2 2 3-4 1-2 2-3 2 1-2 3-4 2-3 1 1-2 1

15 gm NaoH 2 2 3-4 1-2 2 2-3 1-2 3-4 1 1 1

20 gm NaoH 2 2-3 3 1-2 2-3 2-3 1-2 3 2-3 1 1-2 1

25 gm NaoH 2 2 3-4 1-2 2-3 2-3 1-2 3-4 2-3 1 1-2 1

Temperature

120°C 2 2-3 3-4 1-2 2-3 2-3 1-2 3-4 3 1 1-2 1-2

140°C 2 2 3-4 1-2 2-3 2 1-2 3-4 2-3 1 1-2 1

160°C 2 2-3 3 1-2 2-3 2-3 1-2 3-4 2-3 1 1-2 1

180°C 2 2-3 3 1-2 2-3 2-3 1-2 3 3 1 1-2 1-2

Time

1 min. 1-2 2 3 1 2 1-2 1-2 3 2 1 1 1

2 min. 1-2 2 3 1 2 1-2 1-2 3 2 1 1 1

3 min. 1-2 2 3 1 2 1-2 1-2 3 2 1 1 1

4 min. 1-2 1-2 3 1 2 1-2 1-2 3 1 1 1

Ca 5 gm. 2 2-3 3-4 1-2 2 2 2 3 2-3 1-2 1-2 1-2

173

Concentration 10 gm. 2 2-3 3 1-2 2-3 2-3 2 3 3 1 1-2 1-2

15 gm. 2 2 3-4 1-2 2-3 2-3 2 3 2-3 1-2 2 2

20 gm. 2 2-3 3 1-2 2-3 2-3 2 3 2-3 1-2 2 2

65%

cotton-

35%

Polyester

NaoH

concentration

Untreated 2 2-3 3-4 1-2 2-3 2-3 1-2 3 3 1 1-2 1-2

5 gm NaoH 2 2 3 1-2 2-3 2-3 1-2 3 2-3 1 1-2 1

10 gm NaoH 2 2-3 3-4 1-2 2-3 2-3 1-2 3-4 2-3 1 1-2 1-2

15 gm NaoH 2 2-3 3-4 1-2 2-3 2 2 3-4 2-3 1 1-2 1-2

20 gm NaoH 2 2-3 3 1-2 2-3 2 2 3 3 1 1-2 1-2

25 gm NaoH 2 2-3 3-4 1-2 2-3 2-3 1-2 3 3 1 1-2 1-2

Temperature

120°C 2 2 3 1-2 2-3 2-3 1-2 3-4 2-3 1 1-2 1-2

140°C 2 2-3 3-4 1-2 2-3 2 1-2 3-4 2-3 1 1-2 1-2

160°C 2 2-3 3 1-2 2-3 2-3 1-2 3-4 2-3 1 1-2 1-2

180°C 2 2-3 3 1-2 2-3 3 2 3 2-3 1 2 2

Time

1 min. 2-3 2-3 3 1-2 2-3 2-3 1-2 3-4 2-3 1 1-2 1-2

2 min. 2 2-3 3 1-2 2-3 2 1-2 3-4 2-3 1 1-2 1-2

3 min. 2-3 2-3 3 1-2 2-3 2-3 1-2 3 2-3 1 1-2 2

4 min. 2 2-3 3 1-2 2-3 2 2 3 2-3 1 2 1-2

Ca 5 gm. 1-2 2 3 1 2 2 1-2 3 2-3 1 1-2 1-2

174

Concentration 10 gm. 1-2 2-3 3 1 2 2 1-2 3 2-3 1 1-2 1-2

15 gm. 2 2-3 3 1-2 2-3 2-3 2 3 3 1 1-2 1-2

20 gm. 2 2-3 3 1-2 2-3 2-3 2 3 2-3 1 1-2 1-2

Cotton

Temperature

120°C 2-3 3 3-4 2 2-3 2-3 2 3 3 1-2 2 2

140°C 2 2-3 3 1-2 2-3 2-3 2 3 3 1 1-2 1-2

160°C 2-3 2-3 3-4 1-2 2-3 3 1-2 3 3 1 1-2 1-2

180°C 2 2-3 4-5 2 2-3 3 1-2 4 3 1 1-2 1-2

Time

1 min. 2-3 3 3 2 2-3 2-3 2 3-4 3 1-2 2 2

2 min. 2 3 3-4 1-2 2-3 2-3 2 3-4 3 1 2 2

3 min. 2-3 3 3 2 2-3 2-3 2 3 3-4 1-2 2 2

4 min. 2 3 4 1-2 2-3 2-3 1-2 3-4 3-4 1 1-2 1-2

Ca

Concentration

5 gm. 2 2-3 3-4 1-2 3 2-3 2 3-4 2-3 1-2 2 1-2

10 gm. 2 2 3-4 1-2 2 2 1-2 3 2-3 1-2 1-2 1-2

15 gm. 2-3 2-3 3-4 1-2 2-3 2-3 2 3-4 2-3 1-2 2 1-2

20 gm. 2-3 2-3 3 1-2 2-3 2-3 2 3 2-3 1-2 2 2

175

5.4.2. Scanning Electron Microscope (SEM)

Scanning Electron Microscope (SEM) photos were taken of samples before and after chitosan

printing to picture the physical effect of the chitosan treatment on the surface of the four

fabrics handled in this research work.

Figure 5.20: SEM for un treated PET sample

Figure 5.21: SEM for PET sample printed with chitosan

176


Figure 5.23: SEM for 50% cotton – 50% PET sample printed with chitosan


177

Figure 5.25: SEM for 65% cotton – 35% PET sample printed with chitosan

Figure 5.26: SEM for un treated cotton sample

Figure 5.27: SEM for chitosan printed cotton sample

178

From previous figures, it could be seen that the chitosan printing on all four fabrics is

forming a film like coating on the fabric and that it is forming crosslinks with the fibres

which confirms the formation of the chitosan layer of the surface of the textile samples.

5.5. Conclusion

It is clear from the results in this chapter that it is possible to deferential print PET fabrics and

PET/ cotton blends using a chitosan printing paste.

It is possible to dye PET fabrics and PET/ cotton blends with commercially available acid

dyes and it is possible to reach a high colour yield.

Samples printed with chitosan gave higher K/S values than padded samples of the same

fabric which indicates that a build-up process for the colour could be done.

The quality of the colour resultant from deferential printing heavily depends on how much

chitosan is deposited on the fabric surface.

The optimum sodium hydroxide concentration in the pretreatment of PET, blend 1 (50%

Cotton- 50% PET), and blend 2 (65% cotton – 35% PET) was found to be 15 g/L.

The optimum fixation condition for PET samples was at fixation temperature of 200 °C for 3

minutes.

The optimum fixation condition for blend 1 (50% Cotton- 50% PET), blend 2 (65% cotton –

35% PET), and cotton was at fixation temperature of 180 °C for 3 minutes.

179

6. Chapter Six: A novel approach in resist printing of polyester

and polyester/cotton blended fabrics

6.1. Introduction

Resist printing is a style of textile printing that involves the printing of an agent that prevents

the dye from penetration or fixation on the fabric. After fixing this agent, by dying the resist

printed fabric, the area free from the resist agent gets dyed. The resist printed areas stay clear

of the dye (Broadbent et al., 2001).

There are two types of resist agents, physical and chemical resist agents Physical resisting

agents prevent dye absorption by the fabric, a good example on physical resist is the batik

style which involves the print of waxes and fats in a designed print and then dyeing the

fabric. The wax prevents the dye from penetrating the fabric and reacting with it, which

leaves the resist printed areas clear of dyes.

The second type of resist agents is the chemical resisting agents, they work by preventing dye

fixation. These agents react with the fabric or the dye, blocking the active sights on either and

preventing them from reacting with each other, in other words; preventing dye fixation

(Broadbent et al., 2001).

Lots of researches have been conducted on the improvement of resist printing of cotton and

its blends, but there is a lack of research conducted on PET and other synthetic materials.

This is mainly because that the concept of resist printing is heavily dependent on the

resistance of active sites in the resist printed material. A US patent (No 3,414,368: patented

Dec. 3, 1968) has explored the area of resist printing polyester by using a special disperse dye

This disperse dye contains at least two radicals in its molecule, each with an unshared pair of

electrons and are capable of forming complex compounds with metals. The patent authors

used a resist printing paste containing metal compounds, which formed complex compounds

with this specific disperse dye (Kazuo and Norihiro, 1968).

In 2013 a scientific research was conducted on using chitosan in resist printing of cotton and

its blends by using a mixture of chitosan and resist salts in a ratio of 75% resist salt to 25%

chitosan (Rekaby et al., 2013).

They found that this mixture could be used as a resist printing paste which is able of blocking

the active sites on cotton surface and prevent them from reacting with the reactive dye (CNP)

used in the subjected research (Rekaby et al., 2013).

180

There is no other research – up to the author’s knowledge -conducted in the area of resist

printing using chitosan, nor in the area of resist printing of hydrophobic materials such as

PET.

That is why in this section, a research was conducted to study the ability of resist printing

PET fabrics and its blends. The ability to use chitosan in the process of resist printing of

different materials was also studied.

6.2. Initial experimental approaches

The research work had to go through initial trials to find the most suitable approach to start

the research with; these trials are explained below.

4.6.1. The use of chitosan in discharge printing of PET fabrics and its blends

A trial was conducted to study the ability of using the chitosan in discharge printing of PET

samples and its blends. Samples of PET, 50% cotton – 50% PET, and 65% Cotton – 35%

PET fabrics were pretreated with solutions of 15gm/L NaOH and liquor ratio (L:R) 1:20.



Samples were then printed with a printing paste containing:

20 gm Chitosan

3% Acetic acid

Y Water

____________________

1000 gm.

After that samples were air dried overnight, then dyed with a dischargeable reactive dye

Remazol Black B (CI Reactive Black 5). Samples again were air dried and then printed with

a traditional discharge printing paste containing:

70 g Stock Thickener

10 g Rongalite C (sodium formaldehyde sulphate)

Y water

_________________________________________

100 gm

After that samples were steam fixed at 100 °C for 30 min., rinsed with hot and cold water and

then air dried.

181

Samples showed good results with white discharge effect accomplished as shown in figure

6.1.

Figure 6.1: Discharge printing of PET samples and polyester/ cotton blends

This trial was not taken further to a full research because of the health issues related to the

use of formaldehyde releasing sodium formaldehyde sulphate (Rongalite C) (Novick et al.,

2013).

6.2.2. The use of thermo-fixation vs. steam-fixation for resist printing with NaOH and

chitosan

A comparison between using thermo-fixation and steam fixation of PET samples and its

blends was conducted to find out the optimum fixing method for the studied samples. Steam

fixation gave satisfactory results while thermo-fixation was not suitable for the process,

where samples fixed with thermo-fixation formed a chalky layer on top of the resist printed

areas without reacting, this is why the optimum fixation method for this part was the steam

fixation method.

182

6.3. Experiments

6.3.1. Materials

Bleached and scoured 100% polyester (35gm/m2), 50% cotton -50% polyester (26 gm/m

2),

and 65% cotton- 35% polyester (34 gm/m2) were used in this stage of the research. Chitosan

from crab shells with high molecular weight obtained from Sigma Aldrich Japan, acetic and

formic acid, Carboxymethyl cellulose (CMC) thickening agent, and acid dye Sandolan Blue

E-2GL 200% by Sandoz chemicals UK were used.

6.3.2. Methods

6.3.2.1. Polyester and poly/cotton pretreatment

Polyester and cotton/ polyester samples were treated with a solution of 15 gm / L sodium

hydroxide and liquor ratio (L: R) 1:20. The treatment was done at 80° C for 30 minutes,

samples were then rinsed with distilled water and 3% acetic acid.

6.3.2.2. Resist printing

Samples were manually silkscreen printed with different concentrations of NaOH (5, 10, 15,

20, 25 gm) in a resist printing paste consist of:

X gm NaOH

6 gm CMC

Y Water

____________________

100 gm

Where X = (5, 10, 15, 20, 25 gm)

6.3.2.3. Chitosan printing

Resist printed samples with NaOH were then manually silkscreen printed (overlapping the

existed resist prints), with chitosan printing paste consisting of:

20 gm Chitosan

3% Acetic acid

Y Water

____________________

1000 g.

183

Samples were steam fixed at (120, 140, 160, 180 °C) and up to 200 °C in the case of PET

fabrics, for (15, 30, 45 minutes) to study the optimum conditions for fixation. The process is

explained in figure 6.2.

Figure 6.2: Explanation diagram for the resist printing technique

6.3.2.4. Dyeing of printed samples

Resist printed samples were dyed with the acid dye Sandolan Blue E-2GL 200%, in a dye

bath containing:


5% sodium sulphate;

4% formic acid.

The dye bath started with sodium sulphate, and formic acid, at pH 2-3 L:R 1:20, the

dissolved dye was then added and the PH was checked, the treatment lasted for 15 minutes at

40 °C., and finally the temperature was increased to 100 °C over 30 min. and samples were

dyed for 30 minutes. The dyeing process was done on a Mathis Labomat Uniprogrammer lap

dyeing machine.

6.3.2.5. Washing

The fixed resist printed samples were subjected to washing through five stages as follows:

Rinsing thoroughly with cold water.

Washing with hot water.

Treatment with hot water near the boiling temperature (80 °C)

Washing with hot water.

Rinsing with cold water.

White sample Resist Print Chitosan overlapping print

184

6.3.2.6. Samples evaluation

6.3.2.6.1. Colour strength evaluation


spectrophotometer. The colour strength (K/S values) of the dyed samples were assisted

according to a standard method (Judd and Wyszecki, 1975) by measuring the decrease

persentage of K/S values according to equasion 7 (Judd and Wyszecki, 1975).

% 𝐃𝐞𝐜𝐫𝐞𝐚𝐬𝐞 𝐢𝐧 𝐊𝐒⁄ =

𝐂𝟐−𝐂𝟏

𝐂𝟏 𝐗 𝟏𝟎𝟎% (7)

Where

C2 K/S value for chitosan printed area (dark shade)

C1 K/S value for resisted area (light shade)

6.4. Results and discussion

6.4.1. Effect of chitosan fixation temperature on the K/S values of chitosan printed

textile fabrics

The following results show the effect of fixation temperature on the K/S values of resist

printing polyester, 50% cotton-50% PET, and 65% cotton-35% PET fabrics.


After exhaustion, bath samples were washed with distilled water and 3% acetic acid, dried

and printed with a Sodium hydroxide printing paste as explained in 6.3.2.2. After that,

samples were printed with a chitosan printing paste previously explained in 6.3.2.3.

Samples were steam fixed at (120, 140, 160, and 180 ° C) (up to 200 ° C in the case of PET)

for 30 minutes, after that samples were dyed with acid dye Sandolan Blue E-2GL 200%,

washed thoroughly and air dried and then evaluated for colour decrease.

6.4.1.1. Effect of fixation temperature on the percentage decrease in K/S values of

resist printed PET samples

As mentioned in part (6.4.1) PET samples pretreated with NaOH solution of 15 g/L where

printed with NaOH resist printing paste and then with chitosan printing paste, steam fixed for

185

30 minutes at (120, 140, 160, 180, and 200 °C) and then acid dyed to study the effect of

fixation temperature on the K/S percentage decrease values of resist printed PET samples.

Table 6.1 shows the mean values of the percentage decrease in K/s values of resist printed

PET samples of each set of temperature.

Table 6.1: The percentage decrease in K/S means values of resist printed PET samples for

each fixation temperature


120 3 90.3

140 3 94.91

160 3 96.05

180 3 97.14

200 3 97.63

Figure 6.3: Means and standard error for the effect of fixation temperature on the

percentage decrease of K/S values of the resist printed PET samples

From figure 6.3, for a given set of fixation temperatures, it could be seen that the percentage

decrease in the K/S values of resist printed PET samples increase by the increase of fixation

temperature to 180 °C.

By increasing the fixation temperature of resist printed PET samples to 200 °C the percentage

decrease in K/S values of resist printed PET samples slightly increased. The figure also

shows the standard error for each sample as explained previously.

The results are fitting a regression model describing the relationship between the percentage

decrease in K/S values of resist printed PET samples and the fixation temperature.

Means and Standard Errors

Temperature (°C)

% D

ecre

ase in K

/S

120 140 160 180 200

89

91

93

95

97

99

186

The P-value in the regression analysis is 0 (less than 0.05 which shows that there is a

significant relationship between the percentage decreases in K/S values of resist printed PET

samples and the fixation temperature of PET samples at the 95.0% confidence level.

The R2 value of 94.2 % means that the model as fitted explains 94.2 % of the variability in the

percentage decrease in K/S values of the resist printed PET samples.

LSD (Fisher's least significant difference) analysis was done to determine which fixation

temperature is significantly different from another. Table for Multiple range test along with

regression analysis, and Anova tables could be seen in Appendix C.

The Multiple Range Tests showed that there is a significant difference between fixed PET

samples at 120 °C and fixed samples at any other sets of fixation temperature. It also shows

that by increasing the fixation temperature from 180 °C to 200 °C for PET samples the

difference is not significant.

The highest level of difference was at temperature of 200 °C. It could understood that the

fixation temperature of resist printed PET samples would make a significant difference on the

percentage decrease in K/S values of resist printed PET samples and that the highest level of

difference was at temperature of 200 °C.

As a conclusion the optimum fixation temperature of resist printed PET samples was found to

be between 180 and 200 °C as it gave the highest percentage decrease in K/S values and

made the biggest level of difference.

In the upcoming work, a fixation temperature of 200 °C was chosen for the fixation of resist

printed PET samples, taking into account that the optimum fixation temperature for chitosan

direct printed PET samples was 200 °C.


resist printed 50 % cotton – 50 % PET samples

50 % cotton – 50 % PET samples were pretreated with NaOH solution of 15 g/L then printed

with NaOH resist printing paste and then with chitosan printing paste and steam fixed for 30

minutes at (120, 140, 160, and 180 °C), and then acid dyed. This was to study the effect of

fixation temperature on the percentage decrease of K/S values of resist printed 50 % cotton –

50 % PET samples.

Table 6.2 shows the mean value of the percentage decrease in K/S values of resist printed 50

% cotton – 50 % PET samples of each set of temperature for three samples each.

187

Table 6.2: The percentage decrease in K/S means values of resist printed 50 % cotton –

50 % PET samples for each fixation temperature


120 3 90.07

140 3 95.77

160 3 97.45

180 3 98.21


percentage decrease in K/S values of the resist printed 50 % cotton – 50 % PET

samples


decrease in K/S values of resist printed 50 % cotton – 50 % PET samples increased by the

increase of fixation temperature to 160 °C.

By increasing the fixation temperature of resist printed 50 % cotton – 50 % PET samples to

180 °C the percentage decrease in K/S values of resist printed 50 % cotton – 50 % PET

samples slightly increased. The standard error for each sample is shown in figure 6.4.


decrease in K/S values of resist printed 50 % cotton – 50 % PET samples and the fixation

temperature.


significant relationship between the percentage decrease in K/S values of resist printed 50 %

cotton – 50 % PET samples and the fixation temperature of 50 % cotton – 50 % PET samples

at the 95.0% confidence level.

Temperature (°C)

% D

ecre

ase in K

/S


120 140 160 180

89

91

93

95

97

99

188


the percentage decrease in K/S values of resist printed 50 % cotton – 50 % PET samples.

To choose which fixation temperature was significantly different from another, and which

fixation temperature is the most effective one. A Fisher's least significant difference analysis

was done. Table for Multiple range test along with regression analysis, and Anova tables

could be seen in Appendix C.

Results showed that there is a significant difference between 50 % cotton – 50 % PET

samples fixed at 120 °C and samples fixed at any other sets of fixation temperature. They

also show that by increasing the fixation temperature from 160 °C to 180 °C for 50 % cotton

– 50 % PET samples the difference was not significant.

The highest level of difference was at temperature of 180 °C. It could be understood that the

fixation temperature of resist printed 50 % cotton – 50 % PET samples would make a

significant difference on the percentage decrease in K/S values of resist printed 50 % cotton –

50 % PET samples when fixed and that the highest level of difference was at temperature of

180 °C.

As a conclusion the optimum fixation temperature of resist printed 50 % cotton – 50 % PET

samples was found to be between 160 and 180 °C as it gave the highest percentage decrease

in K/S values and made the biggest level of difference. In the upcoming work, a fixation

temperature of 180 °C was chosen for the fixation of resist printed 50 % cotton – 50 % PET

samples.


resist printed 65 % cotton – 35 % PET samples

As mentioned in part (6.4.1) 65 % cotton – 35 % PET samples pretreated with NaOH solution

of 15 g/L were printed with NaOH resist printing paste and then with chitosan printing paste,

steam fixed for 30 minutes at (120, 140, 160, and 180 °C), and then acid dyed to study the

effect of fixation temperature on the percentage decrease of K/S values of resist printed 65 %

cotton – 35 % PET samples.


% cotton – 35 % PET samples of each set of temperature.

189

Table 6.3: The percentage decrease in K/S mean values of resist printed 65 % cotton – 35

% PET samples for each fixation temperature


120 3 94.65

140 3 95.95

160 3 97.02

180 3 97.54


percentage decrease in K/S values of the resist printed 65 % cotton – 35 % PET

samples


decrease in K/S values of resist printed 65 % cotton – 35 % PET samples increased by the

increase of fixation temperature to 180 °C. The standard error for each sample is shown as

well.

The results are fitting a regression model that describes the relationship between the

percentage decrease in K/S values of resist printed 65 % cotton – 35 % PET samples and the

fixation temperature.

The P-value in the regression analysis is 0 (less than 0.05 which shows that there is a

significant relationship between the percentage decrease in K/S value of resist printed 65 %

cotton – 35 % PET samples and the fixation temperature of 65 % cotton – 35 % PET samples

at the 95.0% confidence level.

The R2 value of 98.22% means that the model as fitted explains 98.22% of the variability in


Temperature (°C)

% D

ecre

ase in K

/S


120 140 160 180

94

95

96

97

98

190

LSD (Fisher’s least significant analysis) where conducted to determine which fixation time is

significantly different from another. Tables for Multiple range test along with regression

analysis, and ANOVA tables could be seen in Appendix C.

Results showed that there is a significant difference between steam fixed 65 % cotton – 35 %

PET resist printed samples at 120 °C and fixed samples at any other sets of fixation

temperature.

Results also showed that the highest level of difference was at fixation temperature of 180

°C. It could be concluded that the fixation temperature of resist printed 65 % cotton – 35 %

PET samples would make a significant difference on the percentage decrease in K/S values of

resist printed 65 % cotton – 35 % PET samples and that the highest level of difference was at

temperature of 180 °C.

As a conclusion the optimum fixation temperature of resist printed 65 % cotton – 35 % PET

samples was found to be 180 °C as it gave the highest percentage decrease in K/S values and


6.4.2. Effect of chitosan fixation time on the K/S values of chitosan printed textiles

The following results show the effect of fixation temperature on the K/S values of resist

printing polyester, 50% cotton-50% PET, and 65% cotton-35% PET fabrics.


Samples were washed with distilled water and 3% acetic acid after the exhaustion bath, dried,

printed with a resist printing past as previously explained in 6.3.2.2.

After that, samples were printed (overlapping the resist print) with a chitosan printing paste

as mentioned in 6.3.2.3.

Sample were then steam fixed at 180 ° C except for PET which was fixed at 200 ° C for a set

of fixation time of (15, 30, and 45 minutes), after that samples were dyed with acid dye

Sandolan Blue E-2GL 200%, washed thoroughly and air dried and then evaluated for the

percentage of colour decrease.


resist printed PET samples

PET samples pretreated with NaOH solution of 15 g/L were printed with NaOH resist

printing paste and then with chitosan printing paste and steam fixed at 200 °C for a set of

191

fixation time of (15, 30, and 45 minutes) and then acid dyed to study the effect of fixation

temperature on the percentage decrease in K/S values of resist printed PET samples.

Table 6.4 shows the mean value of the percentage decrease in K/S values of resist printed

PET samples of each set of temperature for three samples each.


each fixation time

Time Number of samples Mean

15 3 93.26

30 3 98.15

45 3 98.28


decrease in K/S values of the resist printed PET samples

From figure 6.6, for a given set of fixation time, it could be seen that the percentage decrease

in K/S values of resist printed PET samples increased by the increase of fixation time to 30

minutes. By increasing the fixation time of resist printed PET samples to 45 minutes the

percentage decrease in K/S values of resist printed PET samples slightly increased.

The P-value in the regression analysis was 0 which is less than 0.05, this shows that there is a

significant relationship between the percentage decrease in K/S values of resist printed PET

samples and the fixation time of PET samples at the 95.0% confidence level.


percentage decrease in K/S values of resist printed PET samples.

Time (minutes)

% D

ecre

ase in K

/S


15 30 45

92

94

96

98

100

192

LSD analysis was done to determine which fixation time is significantly different from

another. This could be seen in Appendix C along with regression analysis and Anova tables.

Results also showed that by increasing the fixation time to 45 minutes the difference in the

percentage decrease in K/S values of resist printed PET samples is not significant. It could

understood that the fixation time of resist printed PET samples would make a significant

difference on the percentage decrease in K/S values of resist printed PET samples and that

the highest level of difference was at fixation time of 45 minutes.

As a conclusion the optimum fixation time of resist printed PET samples was found to be 30

minutes as it gave the highest percentage decrease in K/S values and made the biggest level

of difference. The difference was insignificant when the fixation time was 45 minutes which

gave slightly higher values of the percentage decrease in K/S values of resist printed PET

samples.

In the upcoming work, a fixation time of 30 minutes was chosen for the fixation of resist

printed PET samples, for cost saving purposes and because the difference between results

given at fixation time of 30 and 45 minutes would not satisfy the increase in coasts.

6.4.2.2. Effect of fixation time on the percentage decrease in K/S values of resist

printed 50 % cotton – 50 % PET samples

50 % cotton – 50 % PET samples pretreated with NaOH solution of 15 g/L were printed with

NaOH resist printing paste and then with chitosan printing paste and steam fixed for 180 °C

for a set of fixation time (15, 30, and 45 minutes), and then acid dyed to study the effect of

fixation time on the percentage decrease in K/S values of resist printed 50 % cotton – 50 %

PET samples.


% cotton – 50 % PET samples of each set of time for three samples each.


% PET samples for each fixation time


15 3 96.08

30 3 97.77

45 3 97.47

193


decrease in K/S values of the resist printed 50 % cotton – 50 % PET samples

It could be seen from figure 6.7 that the percentage decrease in K/S values of resists printed

50 % cotton – 50 % PET samples increased by the increase of fixation time to 30 minutes.

By increasing the fixation time of resist printed 50 % cotton – 50 % PET samples to 45

minutes, the percentage decrease in K/S values of resist printed 50 % cotton – 50 % PET

samples decreased. The figure also shows the standard error for each sample under

investigation.


decrease in K/S values of resist printed 50 % cotton – 50 % PET samples and fixation time.



cotton – 50 % PET samples and the fixation time of 50 % cotton – 50 % PET samples at the

95.0% confidence level.



Results of Fisher's least significant difference determining which fixation time is significantly

different from another, along with regression analysis and Anova tables, this could be seen in

Appendix C.

Time (minutes)

% D

ecre

ase in K

/S


15 30 45

95

95.5

96

96.5

97

97.5

98

194

Results of LSD test (Fisher's least significant) showed that by increasing the fixation time

from 30 to 45 minutes for 50 % cotton – 50 % PET samples, the difference was not

significant. The highest level of difference was at fixation time 30 minutes. It could be then

concluded that the fixation time of resist printed 50 % cotton – 50 % PET samples would

make a significant difference on the percentage decrease in K/S values of resist printed 50 %

cotton – 50 % PET samples and that the highest level of difference was at fixation time 30

minutes.

As a conclusion the optimum fixation time of resist printed 50 % cotton – 50 % PET samples

was found to be 30 minutes as it gave the highest percentage decrease in K/S values and


6.4.2.3. Effect of fixation time on the percentage decrease in K/S values of resist

printed 65 % cotton – 35 % PET samples

65 % cotton – 35 % PET samples pretreated with NaOH solution of 15 g/L were printed with

NaOH resist printing paste and then with chitosan printing paste and steam fixed at 180 °C

for a set of fixation time ( 15, 30, and 45 minutes).

Samples were then acid dyed to study the effect of fixation time on the percentage decrease

of K/S values of resist printed 65 % cotton – 35 % PET samples. The mean values of the

percentage decrease in K/S values of resist printed 65 % cotton – 35 % PET samples of each

set of time for three samples each are shown in table 6.6.


% PET samples for each fixation time


15 3 95.2

30 3 96.87

45 3 96.66

195


decrease in K/S values of the resist printed 65 % cotton – 35 % PET samples

From figure 6.8, for a given set of fixation time, it could be seen that the percentage decrease

in K/S values of resist printed 65 % cotton – 35 % PET samples increased by the increase of

fixation time to 30 minutes.

By increasing the fixation time of resist printed 65 % cotton – 35 % PET samples to 45

minutes, the percentage decrease in K/S values of resist printed 65 % cotton – 35 % PET

samples decreased.

The P-value in the regression analysis is 0 (less than 0.05). This indicates that there is a


cotton – 50 % PET samples and the fixation time of 65 % cotton – 35 % PET samples at the


The model as fitted explains 93.29 % of the variability in the percentage decrease in K/S

values of resist printed 65 % cotton – 35 % PET samples.

LSD determined which fixation time is significantly different from another, along with

regression analysis and ANOVA tables could be seen in Appendix C.

Results indicated that there is a significant difference between 65 % cotton – 35 % PET

samples fixed for 15 minutes and samples fixed for any other sets of fixation time.

Time (minutes)

% D

ecre

ase in K

/S

15 30 45

Means and Standard Errors (internal s)

95

95.4

95.8

96.2

96.6

97

196

Results also showed that by increasing the fixation time from 30 to 45 minutes for 65 %

cotton – 35 % PET samples, the difference is not significant. The highest level of difference

was at fixation time of 30 minutes.

It could be understood from results that the fixation time of resist printed 65 % cotton – 35 %

PET samples would make a significant difference on the percentage decrease in K/S values of

resist printed 65 % cotton – 35 % PET samples and that the highest level of difference was at

fixation time of 30 minutes.

As a conclusion the optimum fixation time of resist printed 65 % cotton – 35 % PET samples

was found to be 30 minutes as it gave the highest percentage decrease in K/S values and


6.4.3. Effect of sodium hydroxide concentration in resist printing paste on the

percentage decrease in K/S values of resist printed textile samples

The following results show the effect of NaOH concentration in resist printing paste on the

decrease in K/S values of resist printing polyester, 50% cotton-50% PET, and 65% cotton-

35% PET fabrics.


After exhaustion bath samples were washed with distilled water and 3% acetic acid, dried and

then printed with a NaOH resist printing as explained in 6.3.2.2. After that, samples were

printed with a chitosan printing paste previously explained in 6.3.2.3.

Samples then were steam fixed at 180 ° C except for PET fabrics which were fixed at 200 ° C

for 30 minutes. After that samples were dyed with acid dye Sandolan Blue E-2GL 200%,

washed thoroughly and air dried and then the percentage of colour decrease was evaluated.


values of resist printed PET samples

In this part PET samples pretreated with NaOH solution of 15 g/L were printed with NaOH

resist printing paste containing different sets of NaOH concentration (5, 10, 15, 20, and 25

grams) and then printed with chitosan printing paste and steam fixed at 200 °C for 30

minutes.

Samples were then acid dyed to study the effect of NaOH concentration on the percentage

decrease of K/S values of resist printed PET samples. Table 6.7 shows the mean value of the

197

percentage decrease in K/S values of resist printed PET samples of each set of temperature

for three samples each.


each NaOH concentration


5 3 95.65

10 3 97.39

15 3 98.44

20 3 98.19

25 3 98.12


percentage decrease in K/S values of the resist printed PET samples

From figure 6.9, for a given set of NaOH concentration, it could be seen that the percentage

decrease in K/S values of resist printed PET samples increases by the increase of the NaOH

concentration up to 15 grams.

By increasing the NaOH concentration in the resist printed paste of PET samples to 20 grams

and further to 25 grams, the percentage decrease in K/S values of resist printed PET samples

start to decrease.

This could be because of the noticeable increase in the paste viscosity, which make it harder

to push the paste through the silkscreen mesh and harder to print on the PET samples.

NaOH Concentration (grams)

% D

ecre

ase in K

/S


5 10 15 20 25

95

96

97

98

99

198

The P-value in the regression analysis is 0 showing that there is a significant relationship

between the percentage decrease in K/S values of resist printed PET samples and the NaOH

concentration in the resist printing paste of PET samples at the 95.0% confidence level.

The R2 value means that the model as fitted explains 96.3 % of the variability in the

percentage decrease in K/S values of resist printed PET samples.

LSD (Fisher’s least significant analysis) where conducted to determine which NaOH

concentration is significantly different from another. Table for Multiple range test along with


Results showed that there is a significant difference between PET samples resist printed with

NaOH concentration of 5, 10, and 15 grams. Results also showed that by increasing the

NaOH concentrations to 20 grams the difference in the percentage decrease of K/S values of

resist printed PET samples also significant but in positive which indicate decrease in %

decrease of K/S values of resist printed PET samples. The multiple range tests also showed a

non-significant difference between NaOH concentrations of 20 and 25 grams

It could be then concluded that the NaOH concentration in resist printed paste for PET

samples would make a significant difference on the percentage decrease in K/S values with

any NaOH concentration, and that the highest level of difference was at NaOH concentration

of 15 grams.

As a conclusion the optimum NaOH concentration in the resist printing paste for PET

samples was found to be 15 grams as it gave the highest percentage decrease in K/S values

and made the biggest level of difference.


values of resist printed 50% cotton – 50% PET samples

In this part of the research, 50% cotton – 50% PET samples pretreated with NaOH solution of

15 g/L were printed with NaOH resist printing paste containing different sets of NaOH

concentration (5, 10, 15, 20, and 25 grams) and then printed with chitosan printing paste and

steam fixed at 180 °C for 30 minutes.

To study the effect of NaOH concentration on the percentage decrease of K/S values of resist

printed 50% cotton – 50% PET samples, samples were acid dyed and the percentage decrease

in K/S values was evaluated, results are shown in table 6.8.

199

Table 6.8: The percentage decrease in K/S mean values of resist printed 50% cotton –

50% PET samples for each NaOH concentration


5 3 95.90

10 3 97.29

15 3 98.03

20 3 97.98

25 3 97.94


percentage decrease in K/S values of the resist printed 50% cotton – 50% PET

samples


decrease in K/S values of resist printed 50% cotton – 50% PET samples increases by the

increase of NaOH concentration up to 15 grams.

By increasing the NaOH concentration in the resist printed paste of 50% cotton – 50% PET

samples to 20 grams then to 25 grams, the percentage decrease in K/S values of resist printed

samples starts to decrease.

As aforementioned, this could be because of the higher paste viscosity, which make it harder

to push the paste through the silkscreen mesh hence make it harder to print on the samples..


significant relationship between the percentage decrease in K/S values of resist printed 50%

cotton – 50% PET samples and the NaOH concentration in the resist printing paste at the



% D

ecre

ase in K

/S


5 10 15 20 25

95

96

97

98

99

200

The R2 value indicates that the model as fitted explains 93.12 % of the variability in the

percentage decrease in K/S values of resist printed 50% cotton – 50% PET samples.

LSD (Fisher’s least significant analysis) where conducted to determine which NaOH



There is a significant difference between 50% cotton – 50% PET samples resist printed with

NaOH concentrations 5, 10, and 15 grams. Results showed that by increasing the NaOH

concentrations to 20 and 25 grams the difference in the percentage decrease of K/S values of

resist printed 50% cotton – 50% PET samples is insignificant and in positive which indicate a

slight decrease in the % decrease of K/S values of resist printed 50% cotton – 50% PET

samples.

It could understood from the results that the NaOH concentration in resist printed paste for

50% cotton – 50% PET samples would make a significant difference on the percentage

decrease in K/S values with any NaOH concentration, and that the highest level of difference

was at NaOH concentration of 15 grams.

As a conclusion the optimum NaOH concentration in the resist printing paste for 50% cotton

– 50% PET samples was found to be 15 grams as it gave the highest percentage decrease in

K/S values and made the biggest level of difference.


values of resist printed 65 % cotton – 35% PET samples

65% cotton – 35% PET samples pretreated with NaOH solution of 15 g/L where printed with

NaOH resist printing paste containing different sets of NaOH concentration (5, 10, 15, 20,

and 25 grams), then printed with chitosan printing paste and steam fixed at 180 °C for 30

minutes.

Samples then were acid dyed to study the effect of NaOH concentration on the percentage

decrease of K/S values of resist printed 65% cotton – 35% PET samples PET samples, the

mean values of the percentage decrease in K/S values of resist printed 65% cotton – 35%

PET samples of each set of temperature for three samples each are shown in table 6.9.

201

Table 6.9: The percentage decrease in K/S mean values of resist printed 65% cotton –

35% PET samples for each NaOH concentration


5 3 95.59

10 3 96.69

15 3 97.55

20 3 97.48

25 3 97.26


percentage decrease in K/S values of the resist printed 65% cotton – 35% PET

samples


decrease in K/S values of resist printed 65% cotton – 35% PET samples increased by the

increase of NaOH concentration up to 15 grams.

When increasing the NaOH concentration in the resist printed paste of 65% cotton – 35%

PET samples to 20 grams then to 25 grams, the percentage decrease in K/S values of resist

printed 65% cotton – 35% PET samples started to decrease, this could be a result of the

change of the paste viscosity.

The noticeable increase in the paste viscosity make it harder to push the paste through the

fine holes of the silkscreen mesh hence make it harder to print on the 65% cotton – 35% PET

sample.


% D

ecre

ase in K

/S


5 10 15 20 25

95

95.5

96

96.5

97

97.5

98

202

In the regression analysis, the P-value was 0 (less than 0.05) which shows that there is a

significant relationship between the percentage decrease in K/S values of resist printed 65%

cotton – 35% PET samples and the NaOH concentration in the resist printing paste at the



percentage decrease in K/S values of resist printed 65% cotton – 35% PET samples.

An LSD (Fisher’s least significant analysis) where conducted to determine which NaOH


regression analysis, and ANOVA tables could be seen in Appendix C.

Results showed that there is a significant difference between 65% cotton – 35% PET samples

resist printed with NaOH concentrations of 5, 10, and 15 grams.

By increasing the NaOH concentrations to 20 or to 25 grams the difference in the percentage

decrease of K/S values of resist printed 65% cotton – 35% PET samples is insignificant and

in positive which indicate a slight decrease in the % decrease of K/S values of resist printed

65% cotton – 35% PET samples.

It is concluded from the results that the NaOH concentration in resist printed paste for 65%

cotton – 35% PET samples would make a significant difference on the percentage decrease in

K/S values with any NaOH concentration, and that the highest level of difference was at

NaOH concentration of 15 grams.

6.5. Samples evaluation

6.5.1. Scanning electron microscope (SEM)

Scanning Electron Microscope (SEM) photos were taken of chitosan printed samples and of

resist printed samples to show the physical effect of the NaOH resist printing on the surface

of the three fabrics handled in this part of the research work.

203

Figure 6.12: SEM for chitosan printed PET sample

Figure 6.13: SEM for PET sample resist printed with sodium hydroxide

Figure 6.14: SEM for chitosan printed 50% cotton – 50% PET sample

204

Figure 6.15: SEM for 50% cotton – 50% PET sample resist printed with sodium

hydroxide

Figure 6.16: SEM for chitosan printed 65% cotton – 35% PET sample

Figure 6.17: SEM for 65% cotton – 35% PET sample resist printed with sodium

hydroxide

205

From the previous figures, it is clear that the chitosan film is being successfully removed or

prevented from forming on the surface of the three fabrics, some marks and groves on the

fibres surface caused by the NaOH prints are obvious as well.

6.6. Conclusion

It is clear from the results of this part that it is possible to resist print PET fabrics and its

blends using a resist printing paste of sodium hydroxide and over print it with chitosan.

It is concluded that sodium hydroxide prevents chitosan from attaching to the surface of the

fabric and breaks any linkages between the chitosan and the fabric.

The optimum sodium hydroxide concentration for resist printing PET, Blend 1 (50% cotton-

50% PET), and Blend 2 (65% cotton – 35% PET) was found to be 15 g/Kg of printing paste.

The optimum fixation method for PET samples was found to be steam fixation, at fixation

temperature of 200 °C for 30 minutes.

Blended fabrics (50% cotton- 50% PET) and (65% cotton – 35% PET) optimum fixation

method was also found to be the steam fixation method, at fixation temperature of 180 °C for

30 minutes.

206

Chapter seven: Conclusion and further research

7.1. Conclusion

1- It is concluded that it is possible to dye PET fabrics and their cotton blends using

chitosan pretreatment.

2- It is concluded that it is possible to eliminate the use of carriers and other harmful

chemicals when dying PET fabrics and their cotton blends with acid dyes.

3- The optimum sodium hydroxide concentration was found to be 15 g/L in the

pretreatment of PET, Blend 1 (50% cotton- 50% PET), and Blend 2 (65% cotton –

35% PET) in the chitosan padding process.

4- Fixation temperature of 200 °C for 4 minutes was concluded to be the optimum

fixation condition for chitosan padded PET samples in the chitosan padding process.

5- Fixation temperature of 180 °C for 3 minutes was concluded to be the optimum

fixation condition for Blend 1 (50% cotton- 50% PET), Blend 2 (65% cotton – 35%

PET), and cotton in the chitosan padding process.

6- It is concluded that it is possible to deferential print PET fabrics and PET/ cotton

blends using a chitosan printing paste.

7- It is concluded that it is possible to dye PET fabrics and PET/ cotton blends with

commercially available acid dyes and achieve high colour yields.

8- K/S values of samples printed with chitosan were higher than K/S values of padded

samples of the same fabric. This indicates that a build-up process for the colour could

be achieved.

9- In the deferential printing process, deposited quantity of chitosan on the surface of the

fabric determines the quality of the resultant colour.

10- It is concluded that the optimum sodium hydroxide concentration was found to be 15

g/L in the pretreatment of PET, blend 1 (50% cotton- 50% PET), and blend 2 (65%

cotton – 35% PET) in the chitosan printing process.

11- It is concluded that the fixation temperature of 200 °C for 3 minutes is the optimum

fixation condition for PET samples in the chitosan printing process.

12- It is concluded that the fixation temperature of 180 °C for 3 minutes is the optimum

fixation condition for blend 1 (50% cotton- 50% PET), blend 2 (65% cotton – 35%

PET), and cotton in the chitosan printing process.

207

13- It is concluded that it is possible to print PET fabric and its cotton blends using the

resist printing technique, by using a resist printing paste of sodium hydroxide and

over print it with chitosan.

14- In the resit printing technique, it was concluded that sodium hydroxide prevents the

chitosan from attaching to the fabric surface. It is also concluded that it breaks any

links between the chitosan and the fabric in the areas treated with sodium hydroxide.

15- The optimum sodium hydroxide concentration was concluded to be 15 g/Kg of

printing paste for resist printing PET, Blend 1 (50% cotton- 50% PET), and Blend 2

(65% cotton – 35% PET).

16- Steam fixation was found to be the optimum fixation method for PET samples, at

fixation temperature of 200 °C for 30 minutes in the resist printing technique.

17- The optimum fixation method for (50% cotton- 50% PET) and (65% cotton – 35%

PET) was also the steam fixation method but at fixation temperature of 180 °C for 30

minutes in the resist printing technique.

7.2. Further research

1- Discharge printing involves using Rongalite C (sodium formaldehyde sulphate) which

is a health hazard chemical. Further investigation needed to eliminate using this

substance as it possesses high risk to the users and to the environment. The use of

chitosan could be studied in order to make the discharge printing more environmental

friendly process.

2- Trying the previous applied techniques in this research i.e. padding, deferential and

resist printing on other hard to die materials, i.e. Polyamide fabrics. In the proposed

research a set of experiments could be conducted to study the feasibility of applying

the chitosan to new hard to dye materials such as polyamide using the same process

conducted in the original work.

3- Studying the use of different chemicals, i.e. crosslinkers and additives to enhance the

wet rub resistance of chitosan treated dyed fabrics. The crosslinkers should increase

the ponds formed between chitosan and open linkages on the fabric surface, which

could improve the wet rub resistance of the treated fabrics.

4- Studying the use of chitosan in direct printing by adding the dye directly to the

chitosan printing paste, by doing this, the step of dying process could be eliminated

208

and the dye could be fixed on the fabric surface during the fixation of chitosan hence

further cost reduction could be achieved.

5- Studying the use of chitosan in the preparation of ink jet inks suitable for ink jet

printing of different textile materials. This could be conducted to prepare an ink that

could be used on different materials instead of the traditional inkjet process that

involves using different pretreatment and different inks depending on the type of

material used. Instead it could be a universal ink, useable on all types of materials.

209

8. References

Abdel-Halim, E., Abdel-Mohdy, F., Al-Deyab, S. S. & El-Newehy, M. H. 2010. Chitosan and

monochlorotriazinyl-β-cyclodextrin finishes improve antistatic properties of cotton/polyester

blend and polyester fabrics. Carbohydrate Polymers, 82, PP 202-208.

Abdou, E., El-Hennawi, H. & Ahmed, K. 2012. Preparation of novel chitosan-starch blends

as thickening agent and their application in textile printing. Journal of Chemistry, 2013.

Abou-Okeil, A. & Hakeim, O. A. 2005. Effect of metal ion binding of chitosan on the

printability of pretreated wool fabric. Coloration Technology, 121, PP 41-44.

Al-Sabagh, A. M., Yehia, F. Z., Eshaq, G., Rabie, A. M. & Elmetwally, A. E. 2016. Greener

routes for recycling of polyethylene terephthalate. Egyptian Journal of Petroleum, 25, PP 53-

64.

Ali, N. & El-Khatib, E. 2010. Modification of Wool Fabric to Improve Its Dyeability.

Journal of Natural Fibers, 7, PP 276-288.

Ali, S. W., Rajendran, S. & Joshi, M. 2011. Synthesis and characterization of chitosan and

silver loaded chitosan nanoparticles for bioactive polyester. Carbohydrate Polymers, 83, PP

438-446.

Alonso, D., Gimeno, M., Olayo, R., Vázquez-Torres, H., Sepúlveda-Sánchez, J. D. & Shirai,

K. 2009. Cross-linking chitosan into UV-irradiated cellulose fibers for the preparation of

antimicrobial-finished textiles. Carbohydrate Polymers, 77, PP 536-543.

Ammayappan, L. & Moses, J. J. 2009. Study of antimicrobial activity of aloevera, chitosan,

and curcumin on cotton, wool, and rabbit hair. Fibers and polymers, 10, PP161-166.

Anand, S. C., Kennedy, J. F., Miraftab, M. & Rajendran, S. 2006. Medical textiles and

biomaterials for healthcare, 1St

edn. Woodhead Publishing.

Anton, A. 1981. Polyamide Fiber Reactive Chemical Treatments For Differential Dyeability.

Textile Chemist & Colorist, 13.

Bahmani, S. A., East, G. C. & Holme, I. 2000. The application of chitosan in pigment

printing. Coloration Technology, 116, 94-99.

Becht, G., France, N. L., Kunde, J. & Mueller, K. R. 1972. Differential-dyeing textiles.

Google Patents.

Behary, N., Perwuelz, A., Campagne, C., Lecouturier, D., Dhulster, P. & Mamede, A. 2012.

Adsorption of surfactin produced from Bacillus subtilis using nonwoven PET (polyethylene

terephthalate) fibrous membranes functionalized with chitosan. Colloids and Surfaces B:

Biointerfaces, 90, PP 137-143.

Bhuiyan, M. R., Shaid, A. & Khan, M. 2014. Cationization of cotton fiber by chitosan and its

dyeing with reactive dye without salt. Chemical and Materials Engineering, 2, 96-100.

Broadbent, A. D., Dyers, S. O. & Colourists 2001. Basic principles of textile coloration,

Society of Dyers and Colorists.

British Standards Institution (2012). BS-EN-ISO 6330 :2012. BS-EN-ISO-6330:2012 Textiles

Domestic washing and drying procedures for textile testing. London. British Standards

Institution.

British Standards Institution (2002).BS.EN.ISO-105-X12:2002 Textiles Tests for colour

fastness , Part X12: Colour fastness to rubbing. London. British Standards Institution.

210

British Standards Institution (2009). BS.EN.ISO:105-E04 :2009. BS.EN.ISO:105-E04:2009.

Part E04: Colour fastness to perspiration. London. British Standards Institution.

Bu, G., Wang, C., Fu, S. & Tian, A. 2012. Water-soluble cationic chitosan derivative to

improve pigment-based inkjet printing and antibacterial properties for cellulose substrates.

Journal of Applied Polymer Science, 125, 1674-1680.

Carothers, W. H. 1929. Studies on polymerization and ring formation. I. An introduction to

the general theory of condensation polymers. Journal of the American Chemical Society, 51,

2548-2559.

Chang, Y.-B., Tu, P.-C., Wu, M.-W., Hsueh, T.-H. & Hsu, S.-H. 2008. A study on chitosan

modification of polyester fabrics by atmospheric pressure plasma and its antibacterial effects.

Fibers and Polymers, 9, 307-311.

Chattopadhyaya, D. & Inamdarb, M. 2013. Improvement in properties of cotton fabric

through synthesized nano-chitosan application. Indian Journal of Fibre & Textile Research,

38, 14-21.

Choi, P., Yuen, C., Ku, S. & Kan, C. 2005. Digital ink-jet printing for chitosan-treated cotton

fabric. Fibers and Polymers, 6, 229-234.

Choudhury, A. K. R. 2006. Textile preparation and dyeing, Science Publishers.

Chung, Y.-S., Lee, K.-K. & Kim, J.-W. 1998. Durable press and antimicrobial finishing of

cotton fabrics with a citric acid and chitosan treatment. Textile Research Journal, 68, 772-

775.

Clark, M. 2011. Handbook of Textile and Industrial Dyeing: Applications of Dyes, Elsevier.

Clarke, W. 2013. An introduction to textile printing.

Clipson, J. A. & Roberts, G. A. 1989. Differential dyeing cotton. 1–Preparation and

evaluation of differential dyeing cotton yarn. Journal of the Society of Dyers and Colourists,

105, 158-162.

Clipson, J. A. & Roberts, G. A. 1994. Differential dyeing cotton. Part 2‐stoichiometry of

interaction with acid and direct dyes. Journal of the Society of Dyers and Colourists, 110, 69-

73.

Datamonitor 2011. Textiles Industry Profile: the United Kingdom. MarketLine, a

Datamonitor business.

Dave, J., Kumar, R. & Srivastava, H. C. 1987. Studies on modification of polyester fabrics I:

Alkaline hydrolysis. Journal of Applied Polymer Science, 33, 455-477.

Dawson, T. & Hawkyard, C. 2000. A new millennium of textile printing. Review of Progress

in Coloration and Related Topics, 30, 7-20.

Demir, A., Arık, B., Ozdogan, E. & Seventekin, N. 2010a. The comparison of the effect of

enzyme, peroxide, plasma and chitosan processes on wool fabrics and evaluation for

antimicrobial activity. Fibers and Polymers, 11, 989-995.

Demir, A., Arık, B., Ozdogan, E. & Seventekin, N. 2010b. A new application method of

chitosan for improved antimicrobial activity on wool fabrics pretreated by different ways.

Fibers and Polymers, 11, 351-356.

211

Dev, V. R. G., Venugopal, J., Sudha, S., Deepika, G. & Ramakrishna, S. 2009. Dyeing and

antimicrobial characteristics of chitosan treated wool fabrics with henna dye. Carbohydrate

Polymers, 75, 646-650.

Dusenbury, J. H. & Coe, A. B. 1955. Differential Dyeing as an Indicator of Bilateral

Structure in Wool: New Findings. Textile Research Journal, 25, 354-358.

Edwards, V., Buschle-Diller, G. & Goheen, S. 2006. Modified fibers with medical and

specialty applications, Springer.

El-Tahlawy, K. F., El-Bendary, M. A., Elhendawy, A. G. & Hudson, S. M. 2005. The

antimicrobial activity of cotton fabrics treated with different crosslinking agents and chitosan.

Carbohydrate Polymers, 60, 421-430.

Elnagar, K., Abou Elmaaty, T. & Raouf, S. 2014. Dyeing of Polyester and Polyamide

Synthetic Fabrics with Natural Dyes Using Ecofriendly Technique. Journal of Textiles, 2014,

8.

Enescu, D. 2008. Use of chitosan in surface modification of textile materials. Roumanian

Biotechnological Lettters, 13, 4037-48.

Ennos, A. R. 2007. Statistical and data handling skills in biology, Pearson Education.

Erra, P., Molina, R., Jocic, D., Julia, M., Cuesta, A. & Tascon, J. 1999. Shrinkage properties

of wool treated with low temperature plasma and chitosan biopolymer. Textile Research

Journal, 69, 811-815.

Ferrero, F., Periolatto, M. & Ferrario, S. 2015. Sustainable antimicrobial finishing of cotton

fabrics by chitosan UV-grafting: from laboratory experiments to semi industrial scale-up.

Journal of Cleaner Production, 96, 244-252.

Fité, F. C. 1995. Dyeing polyester at low temperatures: Kinetics of dyeing with disperse dyes.

Textile research journal, 65, 362-368.

Gawish, S. M., Abo El-Ola, S. M., Ramadan, A. M. & Abou El-Kheir, A. A. 2012. Citric acid

used as a crosslinking agent for the grafting of chitosan onto woolen fabric. Journal of

Applied Polymer Science, 123, 3345-3353.

Goldstein, J., Newbury, D. E., Echlin, P., Joy, D. C., Romig Jr, A. D., Lyman, C. E., Fiori, C.

& Lifshin, E. 2012. Scanning electron microscopy and X-ray microanalysis: a text for

biologists, materials scientists, and geologists, Springer Science & Business Media.

Gordon, S. & Hsieh, Y.-L. 2006. Cotton: Science and technology, Woodhead Publishing.

Gupta, V. & Kothari, V. 1997. Manufactured fiber technology, Springer.

Hakeim, O., Abou‐Okeil, A., Abdou, L. & Waly, A. 2005. The influence of chitosan and

some of its depolymerized grades on natural color printing. Journal of applied polymer

science, 97, 559-563.

Hanneman, R. A., Kposowa, A. J. & Riddle, M. D. 2012. Basic statistics for social research,

John Wiley & Sons.

Hao, L., Wang, R., Fang, K. & Cai, Y. 2017. The modification of cotton substrate using

chitosan for improving its dyeability towards anionic microencapsulated nano-pigment

particles. Industrial Crops and Products, 95, 348-356.

He, X., Zhou, Q. & Xie, K. 2014. Effect of PEGylated chitosan on plasma etched PET fabrics

surface properties. Journal of Applied Polymer Science, 131.

212

Hebeish, A., Sharaf, S. & Farouk, A. 2013. Utilization of chitosan nanoparticles as a green

finish in multifunctionalization of cotton textile. International Journal of Biological

Macromolecules, 60, 10-17.

Houck, M. M. 2009. Identification of textile fibres, Woodhead.

Houshyar, S. & Amirshahi, S. H. 2002. Treatment of cotton with chitosan and its effect on

dyeability with reactive dyes. Iranian Polymer Journal, 11, 295-302.

Hsieh, S. H., Huang, Z. K., Huang, Z. Z. & Tseng, Z. S. 2004. Antimicrobial and physical

properties of woolen fabrics cured with citric acid and chitosan. Journal of Applied Polymer

Science, 94, 1999-2007.

Hsieh, Y. L. 2007. 1 - Chemical structure and properties of cotton. Cotton. Woodhead

Publishing.

Huang, K.-S., Wu, W.-J., Chen, J.-B. & Lian, H.-S. 2008. Application of low-molecular-

weight chitosan in durable press finishing. Carbohydrate Polymers, 73, 254-260.

Hudson, S. M. & Smith, C. 1998. Polysaccharides: Chitin and Chitosan: Chemistry and

Technology of Their Use As Structural Materials. In: Kaplan, D. (ed.) Biopolymers from

Renewable Resources. Springer Berlin Heidelberg, PP 96-118.

Ibrahim, N., El-Zairy, E., El-Zairy, M. & Khalil, H. 2013a. Enhancing disperse printing and

ultraviolet protecting of polyester-containing fabrics via pretreatment with

chitosan/polyethylene glycol/dimethylol dihydroxyethylene urea. Journal of Industrial

Textiles, 42, 269-282.

Ibrahim, N. A., Abou Elmaaty, T. M., Eid, B. M. & Abd El-Aziz, E. 2013b. Combined

antimicrobial finishing and pigment printing of cotton/polyester blends. Carbohydrate

Polymers, 95, 379-388.

Ibrahim, N. A., El‐Zairy, E. M., El‐Zairy, M. R. & Khalil, H. M. 2010. Improving transfer

printing and ultraviolet‐blocking properties of polyester‐based textiles using MCT‐β‐CD,

chitosan and ethylenediamine. Coloration Technology, 126, 330-336.

Ingamells, W. 1993. Colour for textiles. Society of Dyers and Colourists.

Iqbal, M. 2008. Textile dyes. Rehbar, Karachi.

Jajpura, L. 2016. Application of Chitosan to Impart Antibacterial Property to Annatto Dyed

Fabric.

Jocic, D., Vílchez, S., Topalovic, T., Navarro, A., Jovancic, P., Julia, M. R. & Erra, P. 2005.

Chitosan/acid dye interactions in wool dyeing system. Carbohydrate polymers, 60, 51-59.

Joshi, M., Ali, S. W., Purwar, R. & Rajendran, S. 2009. Ecofriendly antimicrobial finishing

of textiles using bioactive agents based on natural products. Indian Journal of Fibre and

Textile Research, 34, 295-304.

Judd, D. B. & Wyszecki, G. 1975. Color in Science, Business and Industry. Wiley

Interscience, New York, NY.

Julià, M. R., Pascual, E. & Erra, P. 2000. Influence of the molecular mass of chitosan on

shrink-resistance and dyeing properties of chitosantreated wool. Coloration Technology, 116,

62-67.

Kan, C., Yuen, C., Tsoi, W. & Chan, C. 2011. Ink-jet printing for Plasma-treated Cotton

Fabric with Biomaterial. Asean Journal of Chemical Engineering, 1, 1-7.

213

Kazuo, K. & Norihiro, M. 1968. Resist printing method for hydrophobic fibers.

Kittinaovarat, S. 2004. Using chitosan for improving the dyeability of cotton fabrics with

mangosteen rind dye. J. Sci. Res. Chulalongkorn Univ, 29, 155-164.

Knittel, D. & Schollmeyer, E. 2006. Chitosans for permanent antimicrobial finish on textiles.

Lenzinger Berichte, 85, 124-130.

Lee, S., Cho, J.-S. & Cho, G. 1999. Antimicrobial and blood repellent finishes for cotton and

nonwoven fabrics based on chitosan and fluoropolymers. Textile research journal, 69, 104-

112.

Lim, S.-H. & Hudson, S. M. 2003. Review of Chitosan and Its Derivatives as Antimicrobial

Agents and Their Uses as Textile Chemicals. Journal of Macromolecular Science, Part C,

43, 223-269.

Lim, S.-H. & Hudson, S. M. 2004a. Application of a fiber-reactive chitosan derivative to

cotton fabric as an antimicrobial textile finish. Carbohydrate Polymers, 56, 227-234.

Lim, S. H. & Hudson, S. H. 2004b. Application of a fibre‐reactive chitosan derivative to

cotton fabric as a zero‐salt dyeing auxiliary. Coloration Technology, 120, 108-113.

Lv, J., Zhou, Q., Zhi, T., Gao, D. & Wang, C. 2016. Environmentally friendly surface

modification of polyethylene terephthalate (PET) fabric by low-temperature oxygen plasma

and carboxymethyl chitosan. Journal of Cleaner Production, 118, 187-196.

Maher, R. R. & Wardman, R. H. 2015. The chemistry of textile fibres, Royal Society of

Chemistry.

Manyukova, I. & Safonov, V. 2009. Effect of chitosan on dyeing of chemical fibres. Fibre

Chemistry, 41, 169-173.

Mcgregor, R. 1977. Why Do Differential-Dyeing Polyamides Dye Differentially? Textile

Chemist & Colorist, 9.

Mehta, R. & Combs, R. 1997. Coverage of immature cotton neps in dyed fabrics using

chitosan aftertreatment. American dyestuff reporter, 86, 43-45.

Miles, C. & Leslie, W. 2010. Textile Printing: Revised Second Edition.

Momin, N. H., Padhye, R. & Khatri, A. 2011. Influence of chitosan posttreatment parameters

on the fixation of pigment-based inks on ink-jet-printed cotton fabrics. Journal of Applied

Polymer Science, 119, 2495-2501.

Muzaffar, S., Bhatti, I. A., Zuber, M., Bhatti, H. N. & Shahid, M. 2016. Synthesis,

characterization and efficiency evaluation of chitosan-polyurethane based textile finishes.

International Journal of Biological Macromolecules, 93, Part A, 145-155.

Navard, P. 2013. The European Polysaccharide Network of Excellence (EPNOE).

Carbohydrate polymers, 93, 2-2.

Noppakundilograt, S., Buranagul, P., Graisuwan, W., Koopipat, C. & Kiatkamjornwong, S.

2010. Modified chitosan pretreatment of polyester fabric for printing by ink jet ink.

Carbohydrate Polymers, 82, 1124-1135.

Novick, R. M., Nelson, M. L., Mckinley, M. A., Anderson, G. L. & Keenan, J. J. 2013. The

Effect of Clothing Care Activities on Textile Formaldehyde Content. Journal of Toxicology

and Environmental Health, Part A, 76, 883-893.

214

Öktem, T. 2003. Surface treatment of cotton fabrics with chitosan. Coloration Technology,

119, 241-246.

Park, Y., Koo, K., Kim, S. & Choe, J. 2008a. Improving the colorfastness of poly (ethylene

terephthalate) fabrics with the natural dye of Caesalpinia sappan L. Wood extract and the

effect of chitosan and low‐temperature plasma. Journal of applied polymer science, 109, 160-

166.

Park, Y., Koo, K., Kim, S. & Choe, J. 2008b. Improving the colorfastness of poly(ethylene

terephthalate) fabrics with the natural dye of Caesalpinia sappan L. Wood extract and the

effect of chitosan and low-temperature plasma. Journal of Applied Polymer Science, 109,

160-166.

Pascual, E. & Julià, M. R. 2001. The role of chitosan in wool finishing. Journal of

Biotechnology, 89, 289-296.

Periolatto, M., Ferrero, F., Vineis, C. & Rombaldoni, F. 2013. Multifunctional finishing of

wool fabrics by chitosan UV-grafting: An approach. Carbohydrate Polymers, 98, 624-629.

Pillai, C., Paul, W. & Sharma, C. P. 2009. Chitin and chitosan polymers: Chemistry,

solubility and fiber formation. Progress in Polymer Science, 34, 641-678.

Popelka, A., Novák, I., Lehocký, M., Junkar, I., Mozetič, M., Kleinová, A., Janigová, I.,

Šlouf, M., Bílek, F. & Chodák, I. 2012. A new route for chitosan immobilization onto

polyethylene surface. Carbohydrate polymers.

Raffaele-Addamo, A., Selli, E., Barni, R., Riccardi, C., Orsini, F., Poletti, G., Meda, L.,

Massafra, M. R. & Marcandalli, B. 2006. Cold plasma-induced modification of the dyeing

properties of poly (ethylene terephthalate) fibers. Applied Surface Science, 252, 2265-2275.

Rana, M. S., Al Mamun, M. A., Biswas, S. & Sourov, M. R. F. 2016. Surface Modification of

Wool Fabric with Chitosan and Gamma Radiation.

Ravi Kumar, M. N. 2000. A review of chitin and chitosan applications. Reactive and

functional polymers, 46, 1-27.

Rekaby, M., El-Hennawi, H., Shahin, A. & Ragheb, A. 2013. Utilization of biopolymer in

resist printing of linen fabrics using reactive dyes. Carbohydrate polymers, 98, 1540-1546.

RINAUDO, M. 2006. Chitin and chitosan: properties and applications. Progress in polymer

science, 31, 603-632.

Ristić, N., Jovančić, P., Canal, C. & Jocić, D. 2010. Influence of corona discharge and

chitosan surface treatment on dyeing properties of wool. Journal of Applied Polymer Science,

117, 2487-2496.

Roberts, G. A. F. & Wood, F. A. 2001. A study of the influence of structure on the

effectiveness of chitosan as an anti-felting treatment for wool. Journal of Biotechnology, 89,

297-304.

Sadeghi-Kiakhani, M. & Safapour, S. 2015. Eco-friendly dyeing of treated wool fabrics with

reactive dyes using chitosanpoly(propylene imine)dendreimer hybrid. Clean Technologies

and Environmental Policy, 17, 1019-1027.

Şahan, G. & Demir, A. 2016. A green application of nano sized chitosan in textile finishing.

Journal of Textile & Apparel/Tekstil ve Konfeksiyon, 26.

215

Shahidi, S., Ghoranneviss, M. & Sharifi, S. D. 2014. Effect of atmospheric pressure plasma

treatment/followed by chitosan grafting on antifelting and dyeability of wool fabric. Journal

of Fusion Energy, 33, 177-183.

Shih, C.-Y. & Huang, K.-S. 2003. Synthesis of a polyurethane–chitosan blended polymer and

a compound process for shrink-proof and antimicrobial woolen fabrics. Journal of Applied


Shin, Y. & Yoo, D. I. 1998. Use of chitosan to improve dyeability of DP‐finished cotton (II).

Journal of applied polymer science, 67, 1515-1521.

Shin, Y., Yoo, D. I. & Jang, J. 2001. Molecular weight effect on antimicrobial activity of

chitosan treated cotton fabrics. Journal of Applied Polymer Science, 80, 2495-2501.

Singla, A. & Chawla, M. 2001. Chitosan: Some pharmaceutical and biological aspects‐an

update. Journal of Pharmacy and Pharmacology, 53, 1047-1067.

Sophonvachiraporn, P., Rujiravanit, R., Sreethawong, T., Tokura, S. & Chavadej, S. 2011.

Surface Characterization and Antimicrobial Activity of Chitosan-Deposited DBD Plasma-

Modified Woven PET Surface. Plasma Chemistry and Plasma Processing, 31, 233-249.

Strnad, S., Šauper, O., Jazbec, A. & Stana-Kleinschek, K. 2008. Influence of chemical

modification on sorption and mechanical properties of cotton fibers treated with chitosan.

Textile Research Journal, 78, 390-398.

Teli, M. D., Sheikh, J. & Bhavsar, P. 2013. Multifunctional finishing of cotton using chitosan

extracted from bio-waste. International Journal of Biological Macromolecules, 54, 125-130.

Vílchez, S., Jovančić, P. & Erra, P. 2010. Influence of chitosan on the effects of proteases on

wool fibers. Fibers and Polymers, 11, 28-35.

Vílchez, S., Jovancic, P., Manich, A. M., Julià, M. R. & Erra, P. 2005. Chitosan application

on wool before enzymatic treatment. Journal of Applied Polymer Science, 98, 1938-1946.

Walawska, A., Filipowska, B. & Rybicki, E. 2003. Dyeing Polyester and Cotton-Polyester

Fabrics by Means of Direct Dyestuffs after Chitosan treatment. Fibres and textiles in eastern

europe, 11, 71-74.

Wang, B.-L., Wang, J.-L., Li, D.-D., Ren, K.-F. & Ji, J. 2012. Chitosan/poly (vinyl

pyrollidone) coatings improve the antibacterial properties of poly (ethylene terephthalate).

Applied Surface Science, 258, 7801-7808.

Wijesena, R. N., Tissera, N. D. & De Silva, K. N. 2015. Coloration of cotton fibers using

nano chitosan. Carbohydrate polymers, 134, 182-189.

Wilson, J. 2001. Handbook of textile design, CRC Press.

Ye, W., Leung, M. F., Xin, J., Kwong, T. L., Lee, D. K. L. & Li, P. 2005. Novel core-shell

particles with poly(n-butyl acrylate) cores and chitosan shells as an antibacterial coating for

textiles. Polymer, 46, 10538-10543.

Ye, W., Xin, J. H., Li, P., Lee, K.-L. D. & Kwong, T.-L. 2006. Durable antibacterial finish on

cotton fabric by using chitosan-based polymeric core-shell particles. Journal of Applied


Yen, M.-S. & Chen, C.-W. 2011. Effect of chitosan on resist printing of cotton fabrics with

reactive dyes. African Journal of Biotechnology, 10, 1421-1427.

Yen, M. S. 2001. Application of chitosan/nonionic surfactant mixture in reactive dyes for

dyeing wool fabrics. Journal of applied polymer science, 80, 2859-2864.

216

Yi, H., Wu, L.-Q., Bentley, W. E., Ghodssi, R., Rubloff, G. W., Culver, J. N. & Payne, G. F.

2005. Biofabrication with chitosan. Biomacromolecules, 6, 2881-2894.

Zhang, H. & Zhang, L. 2010. Improving the dyeing properties and softness of hemp fabric

using chitosan and epoxy modified silicone oil. The Journal of the Textile Institute, 101, 849-

857.

Zhang, X., Zhang, Y., Ma, G., Yang, D. & Nie, J. 2015. The effect of the prefrozen process

on properties of a chitosan/hydroxyapatite/poly (methyl methacrylate) composite prepared by

freeze drying method used for bone tissue engineering. RSC Advances, 5, 79679-79686.

Zhang, Z., Chen, L., Ji, J., Huang, Y. & Chen, D. 2003. Antibacterial properties of cotton

fabrics treated with chitosan. Textile research journal, 73, 1103-1106.

217

9. Appendix A:

Data analysis for using the padding process to improve the dyeability of

cotton, polyester, and cotton/polyester blends

9.1. Effect of Chitosan concentration

9.1.1. Effect of chitosan concentration on polyester samples

Number of observations: 15

Number of levels: 5

Summary Statistics

Table 9.1: means and standard deviation for the effect of chitosan concentration on

polyester samples

Concentration Count Means Standard deviation

0 3 0.62 0.0016

5 3 1.6 0.15

10 3 2.74 0.22

15 3 3.83 0.33

20 3 5.29 0.26

Simple Regression

Dependent variable: K/S

Independent variable: chitosan concentration

Correlation Coefficient = 0.99

R-squared = 98.32 percent

The equation of the fitted model is

Y = 0.5 + 0.23 X (8)

218

Figure 9.1: Plot of fitted model for the effect of chitosan concentration on the K/S values of PET

samples

One-Way ANOVA test


PET samples

Source Sum of Squares Df Mean Square F-Ratio P-Value

Between groups 40.42 4 10.11 207.89 0.0000

Within groups 0.49 10 0.05

Multiple Range Tests


concentration

Contrast Sig. Difference

0 - 5 * -0.98

0 - 10 * -2.12

0 - 15 * -3.22

0 - 20 * -4.67

5 - 10 * -1.14

5 - 15 * -2.24

5 - 20 * -3.69

10 - 15 * -1.1

10 - 20 * -2.55

15 - 20 * -1.45 * denotes a statistically significant difference.

Concentration (Grams)

Plot of fitted model for the effect of chitosan concentration on the K/S values

K/S

of PET samples

0 4 8 12 16 20

0

1

2

3

4

5

6

219

9.1.2. Effect of chitosan concentration on 50% cotton - 50% PET (Blend 1) samples


Number of levels: 5

Summary Statistics


cotton - 50% PET samples

Chitosan concentration Count Mean Standard deviation

0 3 1.08 0.11

5 3 1.79 0.2

10 3 2.99 0.19

15 3 4.13 0.15

20 3 5.61 0.17

Simple Regression


Independent variable: Chitosan concentration




Y = 0.84 + 0.23 X (9)

Figure 9.2: Plot of fitted model for the effect of chitosan concentration on the K/S values of 50%


Plot of Fitted Model of chitosan conc. effect on K/S of Blend 1 samples


K/S

0 4 8 12 16 20

0

1

2

3

4

5

6

220

One-Way ANOVA test


50% cotton - 50% PET samples


Between groups 39.66 4 9.92 352.63 0




concentration


0 - 5 * -0.71

0 - 10 * -1.92

0 - 15 * -3.06

0 - 20 * -4.54

5 - 10 * -1.21

5 - 15 * -2.35

5 - 20 * -3.83

10 - 15 * -1.14

10 - 20 * -2.62

15 - 20 * -1.48 * denotes a statistically significant difference.

9.1.3. The effect of chitosan concentration on 65% cotton-35%PET (Blend 2) samples


Number of levels: 5

Summary Statistics



Concentration Count Mean Standard deviation

0 3 1.32 0.09

5 3 2.86 0.26

10 3 3.87 0.25

15 3 4.51 0.26

20 3 5.36 0.24

221

Simple Regression






Y = 1.64 + 0.2 X (10)

Figure 9.3: Plot of fitted model for the effect of chitosan concentration on the K/S values of 65%


One-Way ANOVA test




Between groups 29.23 4 7.3 138.85 0


Chitosan Concentration (grams)

K/S

Plot of Fitted Model for the effect of Chitosan concentration on the K/S values

of 65% cotton-35% PET blended fabrics

0 4 8 12 16 20

0

1

2

3

4

5

6

222



concentration


0 - 5 * -1.53

0 - 10 * -2.55

0 - 15 * -3.19

0 - 20 * -4.04

5 - 10 * -1.02

5 - 15 * -1.66

5 - 20 * -2.51

10 - 15 * -0.65

10 - 20 * -1.5

15 - 20 * -0.85

* denotes a statistically significant difference.

9.1.4. The effect of chitosan concentration on cotton samples


Number of levels: 5

Summary Statistics


cotton samples

Concentration Count Mean Standard deviation

0 3 1.53 0.19

5 3 3.93 0.24

10 3 5.52 0.22

15 3 6.48 0.12

20 3 7.03 0.15

Simple Regression






Y = 2.19 + 0.27 X (11)

223


cotton samples

One-Way ANOVA test


cotton samples


Between groups 59.14 4 14.79 419.62 0




concentration


0 - 5 * -2.4

0 - 10 * -3.99

0 - 15 * -4.95

0 - 20 * -5.5

5 - 10 * -1.6

5 - 15 * -2.56

5 - 20 * -3.1

10 - 15 * -0.96

10 - 20 * -1.51

15 - 20 * -0.55


Plot of Fitted Model of chitosan conc. on K/S of cotton samples


K/S

0 4 8 12 16 20

0

2

4

6

8

224

9.2. Effect of chitosan fixation temperature

9.2.1. The effect of fixation temperature on PET samples


Number of levels: 7

Summary Statistics

Table 9.13: means and standard deviation for the effect of chitosan fixation temperature

on PET samples

Temperature Count Mean Standard deviation

0 3 0.62 0.00

120 3 1.76 0.1

140 3 2.04 0.34

160 3 3.4 0.39

180 3 4.14 0.25

200 3 6.46 0.19

220 3 6.78 0.17

Polynomial Regression analysis


Independent variable: Temperature

Order of polynomial = 2



Y = 0.61 - 0.02 X + 0.0002 X 2

(12)

Figure 9.5: Plot of fitted model for the effect of chitosan fixation temperature on the K/S values

of PET samples

Plot of Fitted Model of fixation temperature on K/S values of PET samples

Temperature (°C)

K/S

0 40 80 120 160 200 240

0

2

4

6

8

225

One-Way ANOVA test

Table 9.14: ANOVA Table for the effect of chitosan fixation temperature on the K/S

values of PET samples


Between groups 100.17 6 16.69 291.33 0




temperature


0 - 120 * -1.14

0 - 140 * -1.42

0 - 160 * -2.77

0 - 180 * -3.53

0 - 200 * -5.85

0 - 220 * -6.17

120 - 140 -0.28

120 - 160 * -1.63

120 - 180 * -2.38

120 - 200 * -4.7

120 - 220 * -5.02

140 - 160 * -1.35

140 - 180 * -2.1

140 - 200 * -4.42

140 - 220 * -4.74

160 - 180 * -0.75

160 - 200 * -3.07

160 - 220 * -3.39

180 - 200 * -2.32

180 - 220 * -2.64

200 - 220 -0.32


9.2.2. The effect of fixation temperature on 50% cotton - 50% PET (Blend 1) samples


Number of levels: 5

226

Summary Statistics


on 50% cotton - 50% PET samples


0 3 1.08 0.11

120 3 2.06 0.19

140 3 4.3 0.19

160 3 5.64 0.28

180 3 5.76 0.24







Y = 1.03 - 0.02 X + 0.0003 X 2

(13)


of 50% cotton - 50% PET samples

One-Way ANOVA test


values of 50% cotton - 50% PET samples


Between groups 53.69 4 13.42 304.53 0


Plot of Fitted Model of fixation temperature effect on K/S values of blend I

Temperature °C

K/S

0 20 40 60 80 100 120 140 160 180 200 220 240

0

2

4

6

8

227



temperature


0 - 120 * -0.98

0 - 140 * -3.22

0 - 160 * -4.56

0 - 180 * -4.68

120 - 140 * -2.24

120 - 160 * -3.58

120 - 180 * -3.7

140 - 160 * -1.34

140 - 180 * -1.46

160 - 180 -0.12


9.2.3. The effect of fixation temp on 65% cotton - 35% PET (Blend 2) samples


Number of levels: 5

Summary statistics


on 65% cotton - 35% PET samples


0 3 1.32 0.09

120 3 2.21 0.26

140 3 4.51 0.3

160 3 5.98 0.34

180 3 6.86 0.21







Y = 1.29 -0.029 X + 0.0003 X 2

(14)

228



One-Way ANOVA test




Between groups 67.67 4 16.92 266.41 0




temperature


0 - 120 * -0.88

0 - 140 * -3.18

0 - 160 * -4.66

0 - 180 * -5.53

120 - 140 * -2.3

120 - 160 * -3.77

120 - 180 * -4.65

140 - 160 * -1.48

140 - 180 * -2.35

160 - 180 * -0.88


Plot of Fitted Model of fixation temp. effect on the K/S of Blend2 samples

Temperature (°C)

K/S

0 20 40 60 80 100 120 140 160 180 200 220 240

0

2

4

6

8

229

9.2.4. The effect of fixation temperature on cotton samples


Number of levels: 5

Summary Statistics analysis


on cotton samples


0 3 1.53 0.19

120 3 2.06 0.29

140 3 4.92 0.28

160 3 6.49 0.17

180 3 7.19 0.17

Polynomial Regression






Y = 1.48 - 0.03 X + 0.0004 X 2

(15)


of cotton samples

Plot of Fitted Model of fixation temperature effect on K/S of cotton samples

Temperature °C

K/S

0 20 40 60 80 100 120 140 160 180 200 220 240

0

2

4

6

8

230

One-Way ANOVA test


values of cotton samples


Between groups 78.53 4 19.63 389.77 0




temperature


0 - 120 * -0.53

0 - 140 * -3.39

0 - 160 * -4.96

0 - 180 * -5.67

120 - 140 * -2.86

120 - 160 * -4.44

120 - 180 * -5.14

140 - 160 * -1.57

140 - 180 * -2.28

160 - 180 * -0.70


9.3. Effect of chitosan fixation Time

9.3.1. The effect of fixation time on PET samples


Number of levels: 5

Summary Statistics

Table 9.25: means and standard deviation for the effect of chitosan fixation time on PET

samples

Time Count Mean Standard deviation

0 3 0.62 0.002

1 3 4.23 0.27

2 3 4.96 0.29

3 3 5.3 0.3

4 3 7.31 0.17



Independent variable: Time




231

Y = 1.02 + 2.73 X - 0.36 X 2

(16)

Figure 9.9: Plot of fitted model for the effect of chitosan fixation time on the K/S values of PET

samples

One-Way ANOVA analysis


PET samples


Between groups 61.02 4 15.26 260.18 0




time


0 - 1 * -3.61

0 - 2 * -4.34

0 - 3 * -4.68

0 - 4 * -6

1 - 2 * -0.73

1 - 3 * -1.07

1 - 4 * -2.39

2 - 3 -0.34

2 - 4 * -1.66

3 - 4 * -1.31


Time (minutes)

K/S

Means and standard deviation of fixation time effect on PET samples

0 1 2 3 4

0

2

4

6

8

232

9.3.2. The effect of fixation time on 50% cotton - 50% PET (Blend 1) samples


Number of levels: 5

Summary Statistics




0 3 1.08 0.11

1 3 4.7 0.22

2 3 5.02 0.35

3 3 5.47 0.16

4 3 5.74 0.15







Y = 1.44 + 2.89 X - 0.47 X 2

(17)

Figure 9.10: Plot of fitted model for the effect of chitosan fixation time on the K/S values of 50%


K/S

Time (minutes)

Plot of Fitted Model of fixation time effect on K/S values of blend I samples

0 1 2 3 4

0

1

2

3

4

5

6

7

8

9

10

233





Between groups 43.39 4 10.85 237.90 0




time


0 - 1 * -3.63

0 - 2 * -3.94

0 - 3 * -4.39

0 - 4 * -4.67

1 - 2 -0.31

1 - 3 * -0.76

1 - 4 * -1.04

2 - 3 * -0.45

2 - 4 * -0.73

3 - 4 -0.28




Number of levels: 5

Summary Statistics




0 3 1.32 0.09

1 3 5.45 0.28

2 3 6.02 0.22

3 3 6.26 0.17

4 3 6.98 0.11







234

Y = 1.76 + 3.26 X - 0.51 X 2

(18)







Between groups 60.15 4 15.04 418.85 0




time


0 - 1 * -4.13

0 - 2 * -4.7

0 - 3 * -4.93

0 - 4 * -5.66

1 - 2 * -0.57

1 - 3 * -0.81

1 - 4 * -1.53

2 - 3 -0.24

2 - 4 * -0.96

3 - 4 * -0.72


Plot of Fitted Model of fixation time effect on K/S of blend 2 samples

Time (minutes)

K/S

0 1 2 3 4

0

2

4

6

8

10

235

9.3.4. The effect of fixation time on cotton samples


Number of levels: 5

Summary Statistics

Table 9.34: means and standard deviation for the effect of chitosan fixation time on

cotton samples


0 3 1.53 0.19

1 3 6.09 0.36

2 3 6.68 0.22

3 3 6.88 0.23

4 3 7.08 0.16







Y = 1.97 + 3.79 X - 0.65 X 2

(19)

Figure 9.12: Plot of fitted model for the effect of chitosan fixation time on the K/S


Plot of Fitted Model of fixation time effect on K/S values of cotton samples

Time (minutes)

K/S

0 1 2 3 4

0

2

4

6

8

10

236



cotton samples


Between groups 65.36 4 16.34 282.60 0




time


0 - 1 * -4.56

0 - 2 * -5.15

0 - 3 * -5.35

0 - 4 * -5.55

1 - 2 * -0.59

1 - 3 * -0.79

1 - 4 * -0.99

2 - 3 -0.21

2 - 4 -0.4

3 - 4 -0.2


9.4. Effect of NaOH concentration

9.4.1. The effect of NaOH concentration on PET samples


Number of levels: 6

Summary Statistics


samples

NaOH concentration Count Mean Standard deviation

0 3 0.62 0.002

5 3 4.32 0.19

10 3 4.78 0.16

15 3 4.99 0.16

20 3 4.22 0.18

25 3 3.91 0.23

237



Independent variable: NaOH concentration




Y = 1.15 + 0.54 X - 0.02 X 2

(20)

Figure 9.13: Plot of fitted model for the effect of NaOH concentration on the K/S values of PET

samples


Table 9.38: ANOVA Table for the effect of NaOH concentration on the K/S values of

PET samples


Between groups 38.9 5 7.78 275.09 0


Plot of Fitted Model of NaOH concentration effect on K/S values of PET samples

NaOH concentration ( grams)

K/S

0 5 10 15 20 25

0

1

2

3

4

5

6

238



concentrations


0 - 5 * -3.71

0 - 10 * -4.16

0 - 15 * -4.37

0 - 20 * -3.6

0 - 25 * -3.29

5 - 10 * -0.46

5 - 15 * -0.67

5 - 20 0.11

5 - 25 * 0.41

10 - 15 -0.21

10 - 20 * 0.56

10 - 25 * 0.87

15 - 20 * 0.77

15 - 25 * 1.08

20 - 25 * 0.31


9.4.2. The effect of NaOH concentration on 50% cotton - 50% PET (Blend 1) samples


Number of levels: 6

Summary Statistics




0 3 1.08 0.11

5 3 5.17 0.17

10 3 5.22 0.28

15 3 5.75 0.22

20 3 5 0.26

25 3 4.29 0.24







239

Y = 1.65 + 0.58 X -0.02 X 2

(21)

Figure 9.14: Plot of fitted model for the effect of NaOH concentration on the K/S values of 50%


One-Way ANOVA




Between groups 43.54 5 8.7 178.59 0




concentrations


0 - 5 * -4.09

0 - 10 * -4.15

0 - 15 * -4.68

0 - 20 * -3.92

0 - 25 * -3.21

5 - 10 -0.06

5 - 15 * -0.59

5 - 20 0.17

5 - 25 * 0.88

10 - 15 * -0.53

10 - 20 0.22

10 - 25 * 0.93

Plot of Fitted Model of NaOH concentration on K/S values of Blend I


K/S

0 5 10 15 20 25

0

1

2

3

4

5

6

240

15 - 20 * 0.76

15 - 25 * 1.46

20 - 25 * 0.71




Number of levels: 6

Summary Statistics




0 3 1.32 0.09

5 3 5.87 0.12

10 3 5.97 0.25

15 3 6.88 0.24

20 3 5.23 0.27

25 3 4.17 0.31







Y = 1.88 + 0.7 X - 0.03 X 2

(22)



Plot of Fitted Model of NaOH concentration effect on K/S values of Blend II


K/S

0 5 10 15 20 25

0

2

4

6

8

241

One-Way ANOVA




Between groups 58.34 5 11.67 224.18 0




concentrations


0 - 5 * -4.55

0 - 10 * -4.65

0 - 15 * -5.56

0 - 20 * -3.91

0 - 25 * -2.85

5 - 10 -0.1

5 - 15 * -1.01

5 - 20 * 0.64

5 - 25 * 1.7

10 - 15 * -0.9

10 - 20 * 0.74

10 - 25 * 1.80

15 - 20 * 1.65

15 - 25 * 2.71

20 - 25 * 1.06


242

Appendix B: Data analysis for differential printing of cotton,

polyester, and cotton/polyester blends with chitosan.

10.

10.1. Effect of NaOH concentration



Number of levels: 6

Summary Statistics


samples


0 3 0.62 0.13

5 3 4.85 0.32

10 3 6.61 0.23

15 3 7.57 0.2

20 3 7.73 0.28

25 3 7.42 0.34







Y = 0.95 + 0.77 X -0.02 X 2

(23)

243

Figure 10.1: Plot of fitted model for the effect of NaOH concentration on the K/S values of PET

samples

One-Way ANOVA


PET samples


Between groups 113.6 5 22.72 339.75 0




concentrations


0 - 5 * -4.24

0 - 10 * -5.99

0 - 15 * -6.95

0 - 20 * -7.11

0 - 25 * -6.8

5 - 10 * -1.75

5 - 15 * -2.71

5 - 20 * -2.88

5 - 25 * -2.56

10 - 15 * -0.96

10 - 20 * -1.12

10 - 25 * -0.81

15 - 20 -0.16

15 - 25 0.15

20 - 25 0.31


Plot of Fitted Model of Naoh conc. effect on K/S values of PET samples


K/S

0 5 10 15 20 25

0

2

4

6

8

244



Number of levels: 6

Summary Statistics




0 3 1.08 0.09

5 3 8.43 0.48

10 3 12.77 0.69

15 3 14.76 0.63

20 3 13.82 0.66

25 3 12.06 0.41







Y = 1.3 + 1.61 X - 0.05 X 2

(24)



Plot of Fitted Model of NaOH conc. effect on K/S values of Blend1 samples


K/S

0 5 10 15 20 25

0

4

8

12

16

245

One-Way ANOVA




Between groups 389.46 5 77.89 272.82 0




concentrations


0 - 5 * -7.36

0 - 10 * -11.69

0 - 15 * -13.68

0 - 20 * -12.75

0 - 25 * -10.98

5 - 10 * -4.34

5 - 15 * -6.33

5 - 20 * -5.39

5 - 25 * -3.63

10 - 15 * -1.99

10 - 20 * -1.05

10 - 25 0.71

15 - 20 0.94

15 - 25 * 2.7

20 - 25 * 1.76




Number of levels: 6

Summary Statistics




0 3 1.32 0.07

5 3 14.31 0.75

10 3 16.69 0.58

15 3 18.44 0.42

20 3 18.39 0.66

25 3 16.8 0.55

246







Y = 2.88 + 1.99 X -0.06 X 2

(25)



One-Way ANOVA




Between groups 642.76 5 128.55 425.23 0




concentrations


0 - 5 * -12.99

0 - 10 * -15.37

0 - 15 * -17.12

0 - 20 * -17.07

0 - 25 * -15.47

Plot of Fitted Model of NaOH conc. effect on K/S values of blend2 samples


K/S

0 5 10 15 20 25

0

4

8

12

16

20

247

5 - 10 * -2.38

5 - 15 * -4.13

5 - 20 * -4.08

5 - 25 * -2.48

10 - 15 * -1.75

10 - 20 * -1.7

10 - 25 -0.1

15 - 20 0.05

15 - 25 * 1.65

20 - 25 * 1.6


10.2. Effect of Temperature

10.2.1. The effect of fixation temperature on PET samples


Number of levels: 6

Summary Statistics


on K/S values of PET samples

temperature Count Mean Standard deviation

0 3 0.62 0.13

140 ᵒC 3 7.05 0.47

160 ᵒC 3 8.27 0.41

180 ᵒC 3 8.8 0.74

200 ᵒC 3 13.7 0.59

220 ᵒC 3 14.68 0.26



Independent variable: temp




Y = 0.65 + 0.0023 X+ 0.00028 X 2

(26)

248


of PET samples





Between groups 386.8 5 77.36 338.98 0




fixation temperature


0 - 140 * -6.44

0 - 160 * -7.65

0 - 180 * -8.23

0 - 200 * -13.09

0 - 220 * -14.07

140 - 160 * -1.21

140 - 180 * -1.79

140 - 200 * -6.65

140 - 220 * -7.63

160 - 180 -0.58

160 - 200 * -5.44

160 - 220 * -6.42

180 - 200 * -4.86

180 - 220 * -5.84

200 - 220 * -0.98


Temperature (°C)

K/S

Plot of Fitted Model of fixation temp. effect on the K/S values of PET samples

0 20 40 60 80 100 120 140 160 180 200 220 240

0

3

6

9

12

15

249



Number of levels: 5

Summary Statistics


on K/S values of 50% cotton - 50% PET samples







Y = 1.02 + 0.04 X + 0.0002 X 2

(27)



Temperature (°C)

K/S

Plot of Fitted Model of fixation temp. effect on K/S values of Blend1 samples

0 20 40 60 80 100 120 140 160 180 200 220 240

0

3

6

9

12

15

18

temperature Count Mean Standard deviation

0 3 1.08 0.09

140 3 8.63 0.42

160 3 13.76 0.48

180 3 14.42 0.81

200 3 15.89 0.36

250





Between groups 440.88 4 110.22 457.7 0






0 - 140 * -7.56

0 - 160 * -12.68

0 - 180 * -13.35

0 - 200 * -14.81

140 - 160 * -5.12

140 - 180 * -5.79

140 - 200 * -7.25

160 - 180 -0.66

160 - 200 * -2.13

180 - 200 * -1.47




Number of levels: 5

Summary Statistics


on K/S values of 65% cotton - 35% PET samples

temp Count Mean Standard deviation

0 3 1.32 0.07

140 3 9.33 0.62

160 3 17.26 0.35

180 3 20.2 0.32

200 3 20.92 0.37



Independent variable: temperature



251


Y = 1.21 + 0.0033 X + 0.0005 X 2

(28)







Between groups 838.17 4 209.54 1397.98 0






0 - 140 * -8

0 - 160 * -15.94

0 - 180 * -18.88

0 - 200 * -19.6

140 - 160 * -7.93

140 - 180 * -10.87

140 - 200 * -11.59

160 - 180 * -2.94

160 - 200 * -3.66

180 - 200 * -0.72


Plot of Fitted Model of fixation temp. effect on K/S values of blend2 samples

Temperature (°C)

K/S

0 20 40 60 80 100 120 140 160 180 200 220 240

0

4

8

12

16

20

24

252

10.2.4. The effect of fixation temperature on cotton samples


Number of levels: 5



on K/S values of cotton samples

temp Count Mean Standard deviation

0 3 1.53 0.12

140 3 13.13 0.38

160 3 19.61 0.36

180 3 21.76 0.62

200 3 24.44 0.28





R-squared = 98 percent


Y = 1.47 + 0.04 X + 0.0004 X 2

(29)


of cotton samples

Temperature (°C)

K/S

Plot of Fitted Model of fixation temp. effect on K/S values of cotton samples

0 40 80 120 160 200 240

0

5

10

15

20

25

253





Between groups 1005.15 4 251.29 1659.39 0






0 - 140 * -11.59

0 - 160 * -18.08

0 - 180 * -20.23

0 - 200 * -22.91

140 - 160 * -6.48

140 - 180 * -8.64

140 - 200 * -11.31

160 - 180 * -2.16

160 - 200 * -4.83

180 - 200 * -2.68





Number of levels: 5





0 3 0.62 0.13

1 3 8.99 0.39

2 3 9.41 0.53

3 3 12.86 0.22

4 3 13.26 0.12






254


Y = 1.35 + 6.6 X -0.92 X 2

(30)

Figure 10.8: Plot of fitted model for the effect of chitosan fixation time on the K/S values of PET

samples



PET samples


Between groups 310.72 4 77.68 761.12 0




fixation time


0 - 1 * -8.37

0 - 2 * -8.79

0 - 3 * -12.25

0 - 4 * -12.65

1 - 2 -0.42

1 - 3 * -3.88

1 - 4 * -4.28

2 - 3 * -3.46

2 - 4 * -3.86

3 - 4 -0.4


Plot of Fitted Model of fixation time effect on K/S values of PET samples

Time (minutes)

K/S

0 1 2 3 4

0

3

6

9

12

15

255



Number of levels: 5





0 3 1.07 0.09

1 3 9.73 1.02

2 3 11.21 0.46

3 3 12.36 0.53

4 3 14.73 0.46







Y = 1.99 + 6.68 X -0.92 X 2

(31)

Figure 10.9: Plot of fitted model for the effect of chitosan fixation time on the K/S values


Plot of Fitted Model of fixation time effect on K/S values of blend1 samples

Time (minutes)

K/S

0 1 2 3 4

0

4

8

12

16

256





Between groups 326.79 4 81.69 234.83 0




fixation time


0 - 1 * -8.66

0 - 2 * -10.14

0 - 3 * -11.29

0 - 4 * -13.65

1 - 2 * -1.48

1 - 3 * -2.63

1 - 4 * -4.99

2 - 3 * -1.15

2 - 4 * -3.52

3 - 4 * -2.36




Number of levels: 5





0 3 1.32 0.06

1 3 10.6 1.24

2 3 11.74 0.63

3 3 13.78 0.57

4 3 18.82 0.75





257



Y = 2.54 + 5.98 X - 0.54 X 2

(32)

Figure 10.10: Plot of fitted model for fixation time effect on K/S values of 65% Cotton - 35%

PET samples





Between groups 488.92 4 122.23 216.5 0




fixation time


0 - 1 * -9.27

0 - 2 * -10.41

0 - 3 * -12.46

0 - 4 * -17.5

1 - 2 -1.14

1 - 3 * -3.18

1 - 4 * -8.22

2 - 3 * -2.05

2 - 4 * -7.09

3 - 4 * -5.04


Time (minutes)

K/S

Plot of Fitted Model of fixation time effect on K/S of blend2 samples

0 1 2 3 4

0

4

8

12

16

20

258

10.3.4. The effect of fixation time on cotton samples


Number of levels: 5





0 3 1.53 0.12

1 3 12.68 0.57

2 3 13.63 0.48

3 3 15.88 0.45

4 3 19.97 0.91







Y = 2.89 + 7.68 X - 0.92 X 2

(33)

Figure 10.11: Plot of fitted model for fixation time effect on K/S values of Cotton samples

Time (minutes)

K/S

Plot of Fitted Model of fixation time effect on K/S values of cotton samples

0 1 2 3 4

0

4

8

12

16

20

24

259



cotton samples


Between groups 565.88 4 141.47 441.67 0




fixation time


0 - 1 * -11.15

0 - 2 * -12.1

0 - 3 * -14.36

0 - 4 * -18.44

1 - 2 -0.95

1 - 3 * -3.21

1 - 4 * -7.29

2 - 3 * -2.25

2 - 4 * -6.33

3 - 4 * -4.08


10.4. Effect of chitosan concentration

10.4.1. The effect of chitosan concentration on PET samples


Number of levels: 5



K/S values of PET samples

Chitosan concentration Count Average Standard deviation

0 3 0.62 0.13

5 3 5.68 0.49

10 3 7.21 0.59

15 3 8.01 0.49

20 3 12.06 0.56




260




Y = 1.28 + 0.66 X -0.0079 X 2

(34)

Figure 10.12: Plot of fitted model for chitosan concentration effect on K/S values of PET

samples



PET samples


Between groups 206.41 4 51.6 218.65 0




concentrations


0 - 5 * -5.06

0 - 10 * -6.59

0 - 15 * -7.39

0 - 20 * -11.4

5 - 10 * -1.53

5 - 15 * -2.33

5 - 20 * -6.38

10 - 15 -0.8

10 - 20 * -4.85

Plot of Fitted Model of chitosan conc. effect on K/S values of PET samples


K/S

0 4 8 12 16 20

0

3

6

9

12

15

261

15 - 20 * -4.05


10.4.2. The effect of chitosan concentration on 50 % cotton - 50% PET (Blend 1)

samples


Number of levels: 5

Summary Statistics


K/S values of 50 % cotton - 50% PET samples

Chitosan concentration Count Average Standard deviation

0 3 1.07 0.09

5 3 6.27 0.36

10 3 7.32 0.45

15 3 8.69 0.93

20 3 12.17 0.31



Independent variable: chitosan concentration




Y = 1.74 + 0.67 X -0.008 X 2

(35)

Figure 10.13: Plot of fitted model for chitosan concentration effect on K/S values of 50 % cotton

- 50% PET samples

Plot of Fitted Model of chitosan conc. effect on K/S values of blend1 samples


K/S

0 4 8 12 16 20

0

3

6

9

12

15

262



50 % cotton - 50% PET samples


Between groups 195.99 4 48.99 187.6 0




concentrations


0 - 5 * -5.19

0 - 10 * -6.24

0 - 15 * -7.62

0 - 20 * -11.09

5 - 10 * -1.05

5 - 15 * -2.43

5 - 20 * -5.9

10 - 15 * -1.38

10 - 20 * -4.86

15 - 20 * -3.47


10.4.3. The effect of chitosan concentration on 65 % cotton – 35 % PET (Blend 2)

samples


Number of levels: 5

Summary Statistics


K/S values of 50 % cotton - 50% PET samples


0 3 1.32 0.06

5 3 6.74 0.56

10 3 8.29 0.58

15 3 9.57 0.75

20 3 14.05 0.67






263


Y = 2.03 + 0.69 X-0.0062 X 2

(36)

Figure 10.14: Plot of fitted model for chitosan concentration effect on K/S values of 65 % cotton

- 35% PET samples





Between groups 256.01 4 64 191.21 0




concentrations


0 - 5 * -5.42

0 - 10 * -6.97

0 - 15 * -8.25

0 - 20 * -12.72

5 - 10 * -1.56

5 - 15 * -2.84

5 - 20 * -7.31

10 - 15 * -1.28

10 - 20 * -5.75

15 - 20 * -4.47


Plot of Fitted Model of chitosan conc. effect on K/S values of blend2 samples


K/S

0 4 8 12 16 20

0

3

6

9

12

15

264

10.4.4. The effect of chitosan concentration on cotton samples


Number of levels: 5

Summary Statistics


K/S values of cotton samples


0 3 1.53 0.12

5 3 8.68 0.41

10 3 9.96 0.48

15 3 11.55 0.75

20 3 16.44 0.69







Y = 2.49 + 0.89 X-0.012 X 2

(37)

Figure 10.15: Plot of fitted model for chitosan concentration effect on K/S values of cotton

samples

Plot of Fitted Model of chitosan concentration effect on K/S of cotton samples


K/S

0 4 8 12 16 20

0

3

6

9

12

15

18

265



cotton samples


Between groups 349.94 4 87.48 298.73 0




concentrations


0 - 5 * -7.14

0 - 10 * -8.43

0 - 15 * -10.02

0 - 20 * -14.90

5 - 10 * -1.28

5 - 15 * -2.87

5 - 20 * -7.76

10 - 15 * -1.59

10 - 20 * -6.48

15 - 20 * -4.88


267

11. Appendix C: Data analysis for the resist printing of polyester

and polyester/cotton blended fabrics

11.1. Effect of chitosan fixation temperature

11.1.1. The effect of chitosan fixation temperature on PET samples


Number of levels: 5

Summary Statistics


on K/S values of PET samples


120 3 90.3 0.93

140 3 94.91 0.68

160 3 96.05 0.39

180 3 97.14 0.1

200 3 97.63 0.12







Y = 45.003 + 0.56 X - 0.0015 X 2

(38)

268

Figure 11.1: Plot of fitted model for the effect of chitosan fixation temperature on K/S values of

PET samples





Between groups 103.31 4 25.83 85.74 0


Multiple Range Tests for PET by Temperature


temperature


120 - 140 * -4.61

120 - 160 * -5.75

120 - 180 * -6.84

120 - 200 * -7.33

140 - 160 * -1.14

140 - 180 * -2.23

140 - 200 * -2.72

160 - 180 * -1.09

160 - 200 * -1.58

180 - 200 -0.48


Temperature (°C)

% D

ecre

ase in K

/S

Plot of Fitted Model

120 140 160 180 200

89

91

93

95

97

99

269

11.1.2. The effect of fixation temperature on 50 % cotton - 50% PET (Blend 1)

samples


Number of levels: 4

Summary Statistics


on K/S values of 50 % cotton - 50% PET samples


120 3 90.07 0.84

140 3 95.77 0.49

160 3 97.45 0.18

180 3 98.21 0.11







Y = 7.8 + 1.06 X - 0.003 X 2

(39)



Temperature (°C)

% D

ecre

ase in K

/S


120 130 140 150 160 170 180

89

91

93

95

97

99

270



values of 50 % cotton - 50% PET samples


Between groups 121.95 3 40.65 163.86




temperature


120 - 140 * -5.7

120 - 160 * -7.38

120 - 180 * -8.14

140 - 160 * -1.68

140 - 180 * -2.44

160 - 180 -0.76


11.1.3. The effect of fixation temperature on 65 % cotton - 35% PET (Blend 2)

samples


Number of levels: 4

Summary Statistics


on K/S values of 65 % cotton - 35% PET samples


120 3 94.64 0.32

140 3 95.94 0.07

160 3 97.02 0.01

180 3 97.54 0.11







Y = 78.24 + 0.19 X - 0.00048 X 2

(40)

271







Between groups 14.72 3 4.91 158.83 0




temperature


120 - 140 * -1.29

120 - 160 * -2.37

120 - 180 * -2.88

140 - 160 * -1.08

140 - 180 * -1.59

160 - 180 * -0.51


Temperature (°C)

% D

ecre

ase in K

/S


120 130 140 150 160 170 180

94

95

96

97

98

272




Number of levels: 3

Summary Statistics




15 3 93.26 0.73

30 3 98.15 0.06

45 3 98.28 0.01







Y = 83.61 + 0.8 X -0.01 X 2

(41)


samples

Time (minutes)

% D

ecre

ase in K

/S


15 20 25 30 35 40 45

92

94

96

98

100

273



PET samples


Between groups 49.1 2 24.55 138.31 0




fixation time


15 - 30 * -4.88

15 - 45 * -5.02

30 - 45 -0.13


11.2.2. The effect of fixation time on 50 % cotton - 50% PET (Blend 1) samples


Number of levels: 3

Summary Statistics




15 3 96.08 0.35

30 3 97.77 0.019

45 3 97.46 0.03







Y = 92.39 + 0.31 X - 0.0044 X 2

(42)

274

Figure 11.5: Plot of fitted model for the effect of chitosan fixation time on K/S values of 50 %




% cotton - 50% PET samples


Between groups 4.87 2 2.44 57.41 0




fixation time


15 - 30 * -1.69

15 - 45 * -1.38

30 - 45 0.31


11.2.3. The effect of fixation time on 65 % cotton - 35% PET (Blend 2) samples


Number of levels: 3

Time (Minutes)

% D

ecre

ase in K

/S


15 20 25 30 35 40 45

95

95.5

96

96.5

97

97.5

98

275

Summary Statistics




15 3 95.2 0.33

30 3 96.87 0.16

45 3 96.66 0.21







Y = 91.63 + 0.3 X - 0.0042 X 2

(43)

Figure 11.6: Plot of fitted model for the effect of chitosan fixation time on K/S values of






Between groups 4.99 2 2.49 41.68 0


Time (minutes)

% D

ecre

ase in K

/S


15 20 25 30 35 40 45

94

95

96

97

98

276



fixation time


15 - 30 * -1.68

15 - 45 * -1.46

30 - 45 0.21


11.3. Effect of NaOH concentration in the resist printing paste



Number of levels: 5

Summary Statistics



NaOH Concentration Count Mean Standard deviation

5 3 95.65 0.13

10 3 97.39 0.1

15 3 98.44 0.12

20 3 98.19 0.09

25 3 98.12 0.17



Independent variable: NaOH Concentration




Y = 93.37 + 0.54 X - 0.01 X 2

(44)

277


samples



PET samples


Between groups 15.53 4 3.88 250.79 0




concentrations


5 - 10 * -1.75

5 - 15 * -2.79

5 - 20 * -2.54

5 - 25 * -2.47

10 - 15 * -1.05

10 - 20 * -0.79

10 - 25 * -0.72

15 - 20 * 0.26

15 - 25 * 0.33

20 - 25 0.07



% D

ecre

ase in K

/S


0 5 10 15 20 25

95

96

97

98

99

278

11.3.2. The effect of NaOH concentration on 50 % cotton - 50% PET (Blend 1)

samples


Number of levels: 5

Summary Statistics




5 3 95.9 0.28

10 3 97.29 0.25

15 3 98.03 0.16

20 3 97.97 0.26

25 3 97.94 0.19







Y = 94.18 + 0.41 X -0.01 X

2 (45)




% D

ecre

ase in K

/S


0 5 10 15 20 25

95

96

97

98

99

279





Between groups 9.82 4 2.46 45.15 0




concentrations


5 - 10 * -1.39

5 - 15 * -2.13

5 - 20 * -2.08

5 - 25 * -2.04

10 - 15 * -0.74

10 - 20 * -0.69

10 - 25 * -0.65

15 - 20 0.05

15 - 25 0.09

20 - 25 0.04


11.3.3. The effect of NaOH concentration on 65 % cotton - 35% PET (Blend 2)

samples


Number of levels: 5

Summary Statistics




5 3 95.59 0.19

10 3 96.69 0.27

15 3 97.55 0.27

20 3 97.48 0.16

25 3 97.26 0.18

280







Y = 93.89 + 0.39 X -0.01 X 2

(46)







Between groups 7.94 4 1.98 40.74 0


Total (Corr.) 8.42 14


% D

ecre

ase in K

/S


0 5 10 15 20 25

95

95.5

96

96.5

97

97.5

98

281



concentrations


5 - 10 * -1.09

5 - 15 * -1.96

5 - 20 * -1.88

5 - 25 * -1.67

10 - 15 * -0.86

10 - 20 * -0.79

10 - 25 * -0.57

15 - 20 0.08

15 - 25 0.29

20 - 25 0.21


novel approaches in textile surface modifications for

Documents