Jonathan Marks

Fernando Robelo

Durable Flame Retardant for

Cellulosic Fabric

Summary• Introduction

• Background

• Experimental

• Results and Discussion

• Conclusion

• Further Research

Introduction• Cellulosic fiber

• Important biopolymer • Available in vast

quantities• Good mechanical

properties• Good biodegradability• Good hydrophilicity

• Disadvantages• Ease of thermal

degradation, ignition and burning

• Increases risk of injury or property damage

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Background• Flame retardants

• Chemicals added to polymers to prevent combustion and delay the spread of fire

• Based on halogen, nitrogen and organic-phosphorus compounds

• Involves the use of formaldehyde during manufacturing or application

• Novel halogen- and formaldehyde-free flame retardant (Neo-FR)• Halogen based FRs have potentially toxic effects• Formaldehyde is a known carcinogen

Synthesis of Neo-FR• Step 1

• Solution of phosphonitrilic chloride trimer in tetrahydrofuran was added to a solution of triethylamine and acrylamide

• Product was filtered to remove triethylammonium chloride

• THF was removed using a rotary evaporator

• Step 2• Branched polyethyleneimine solution was applied onto

cotton fabric followed by Neo-FR compound solution

Synthesis of Neo-FR

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Experiment• Neo-FR tested against commercially available flame

retardant agent (Pyrovatex CP New)

• Tests• Chemical structure characterized by Fourier-

transform infrared spectroscopy (FTIR)• Surface morphology and fiber char residue

observed through scanning electron microscope (SEM)

• Thermal property examined by thermal gravimetric analysis (TGA)

• FR performance before and after laundering evaluated by limiting oxygen index (LOI) and vertical flammability tests

• Tensile strength of untreated and treated fabric measured

Results and Discussion

Analysis of FTIR Spectra• NH2 : 3357 and

1596 cm-1

• P=N : 1313 and 1224 cm-1

• P-N : 874 cm-1

• P-Cl : 599cm-1

• As the reaction occurs, peak at 1250 cm-1 strengthens and at 599 cm-1 disappears

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Surface MorphologyFigure A&B: Surface of cotton fibres

Figure C&D: Surface of cotton fibres after burning

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Thermal Properties of Cotton Fabric

• Result clearly shows the high flame retardant property of the Neo- FR finishing

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Limiting Oxygen Index vs. Weight Gain

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Vertical Flammability TestSamples Launderi

ng cyclesAfter flame time(s)

After glow time(s)

Char length (mm)

Neo-FR treated fabric

0 0 0 7620 0 0 10330 0 0 110

Pyrovatex CP new treated fabric

0 0 0 7320 0 0 8630 0 0 98

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Tensile Strength of untreated and FR treated fabrics

Item Tensile strength (N) in weft direction

Tensile strength (N) in warp direction

Elongation at break (%) in weft direction

Elongation at break (%) in warp direction

Control 483 941 20.8 30.9

Neo-FR treated fabric

476 878 16.6 19.3

Pyrovatex CP new treated fabric

417 816 8.6 7.5

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Conclusions• A halogen-free and formaldehyde-free flame

retardant was synthesized and applied to cellulosic fabrics

• LOI and Vertical Flammability test indicate that the flame retardant has excellent flame retardant properties and durability for cellulosic fabrics by a low temperature finishing process

• Could be well used as a durable flame retardant system for cellulosic material

Further Research• Given the properties of the product, it may be

implemented in products already

• Since the ban of the brominated fire retardants in 2006, research has been implemented

• Ever since, phosphorus based fire retardants have started to become popular

Questions?

Zongyue Yang, Xiaowen Wang, Dapeng Lei, Bin Fei, John H. Xin, A durable flame retardant for cellulosic fabrics, Polymer Degradation and Stability, Volume 97, Issue 11, November 2012, Pages 2467-2472, ISSN 0141-3910, 10.1016/j.polymdegradstab.2012.05.023. (http://www.sciencedirect.com.lib-ezproxy.tamu.edu:2048/science/article/pii/S0141391012001978)

Ike van der Veen, Jacob de Boer, Phosphorus flame retardants: Properties, production, environmental occurrence, toxicity and analysis, Chemosphere, Volume 88, Issue 10, August 2012, Pages 1119-1153, ISSN 0045-6535, 10.1016/j.chemosphere.2012.03.067. (http://www.sciencedirect.com.lib-ezproxy.tamu.edu:2048/science/article/pii/S0045653512004353)

K. Kalachova, P. Hradkova, D. Lankova, J. Hajslova, J. Pulkrabova, Occurrence of brominated flame retardants in household and car dust from the Czech Republic, Science of The Total Environment, Volume 441, 15 December 2012, Pages 182-193, ISSN 0048-9697, 10.1016/j.scitotenv.2012.09.061. (http://www.sciencedirect.com/science/article/pii/S0048969712012612)

References