the synthesis of polyol from rice bran oil (rbo) through

The Synthesis of Polyol from Rice Bran Oil

(RBO) through Epoxidation and

Hydroxylation Reactions

by

Edy Purwanto

School of Chemical Engineering

The University of Adelaide

A thesis submitted for the degree of

Master of Engineering Science

July 2010

ii

Declaration

This work contains no material which has been accepted for the award of any other

degree or diploma in any university or other tertiary institution to Edy Purwanto and,

to the best of my knowledge and belief, contains no material previously published or

written by another person, except where due reference has been made in the text.

I give consent to this copy of my thesis when deposited in the University Library,

being made available for loan and photocopying, subject to the provisions of the

Copyright Act 1968.

The author acknowledges that copyright of published works contained within this

thesis (as listed below) resides with the copyright holders(s) of those works.

Conference paper:

E. Purwanto, Y. Ngothai, B. O’Neill, and K. Bremmell, ‘Optimization of

epoxidation reaction of rice bran oil using response surface methodology’,

Proceedings: Chemeca 2009-37th Australasian Chemical Engineering Conference,

The Institution of Engineers, Perth, Australia, 27–30 September 2009, ISBN: 0-

85825-823-4, CD-ROM.

I also give permission for the digital version of my thesis to be made available on

the web, via the University’s digital research repository, the Library catalogue, the

Australasian Digital Theses Program (ADTP) and also through web search engines,

unless permission has been granted by the University to restrict access for a period

of time.

Mr. Edy Purwanto : …………….

Date : 9 July 2010

iii

Summary

Polyurethanes are valuable polymers with a wide variety of applications. They are

normally produced from polyol feedstocks derived from petroleum. As petroleum is

a non-renewable resource, an alternative source of feedstock is sought. A potential

source is rice bran oil. However, far too little attention has been paid to the

utilization of rice bran oil as a potential raw material to produce polyol as it contains

unsaturated fatty acids that can be converted to polyol and is the by product of rice

milling process and available at very low cost.

There are two sequential processes to produce polyol from rice bran oil, namely the

epoxidation and hydroxylation reactions. In this work, the optimal conditions in the

epoxidation reaction were investigated using acetic acid and formic acid as oxygen

carriers in terms of reaction time and temperature. Furthermore, the reaction kinetics

were also determined using formic acid as an oxygen carrier in the epoxidation step.

Finally, the influence of reaction time and temperature in the hydroxylation step

were also investigated in this study.

In order to determine the optimal condition, the epoxidation reaction was performed

in a three neck flask with the use of acetic and formic acid as oxygen carriers. Result

shows that the conversion of iodine value increased with reaction time and

temperature when acetic acid was used as an oxygen carrier (peroxyacetic acid).

Interestingly, the oxirane content increased with reaction time and temperature then

declined after having achieved the optimal point. The optimal condition was

achieved at a reaction time of 4.3 h and a temperature of 63.8oC by performing

response surface methodology.

The conversion of iodine value also displayed similar behaviour during the

epoxidation reaction when formic acid was used as an oxygen carrier (peroxyformic

acid), namely the conversion increased with reaction time and temperature. The

measured rate constants were 0.172h-1

(40oC), 0.304h

-1(50

oC), 0.374h

-1(60

oC),

0.425h-1

(70oC) and 0.492h

-1(80

oC). The activation energy was 22.6 kJ/mol and the

epoxidation reaction was pseudo-first order with respect to the concentration of

iv

double bonds in the oil. Interestingly, peroxyformic acid shows improved

performance as indicated by higher content of maximal oxirane content 3.26%

compared to peroxyacetic acid which is only 2.62%. The optimal condition with the

use of formic acid as an oxygen carrier was obtained at reaction time of 4 h and

temperature of 60oC.

In the hydroxylation step, results indicate that the hydroxyl value of polyol was a

quadratic function of reaction time and temperature and the optimal condition was

achieved at a reaction time of 125.5 min and temperature of 49oC, with maximal

hydroxyl value 161.5 mg KOH/g oil by performing response surface methodology.

The viscosity of polyol increased with reaction time and temperature and resulted in

polyol with viscosity in the range 29.9 – 95.3 cP. Temperature was found to have the

most significant effect on the viscosity of polyol.

The results of this study confirm the potential of rice bran oil as a feedstock for

synthesis of polyol and show that the optimal conditions in the epoxidation and

hydroxylation reactions are a key control variable to obtain a high quality of polyol.

v

Acknowledgement

I would like to express my appreciation to numerous people who have greatly

contributed and assisted me to complete this research study. In particular I would

like to acknowledge:

• Dr Yung Ngothai, School of Chemical Engineering, University of Adelaide,

as principal supervisor for the supervision, motivation, ideas, discussions,

experience in the class and the opportunity to conduct research in the

laboratory.

• A/Prof Brian O’Neill, School of Chemical Engineering, University of

Adelaide, as co-supervisor for the supervision, support, ideas, discussions

and guidance for design of the experiments and the use of response surface

methodology which is a new knowledge for me.

• Dr Kristen Bremmell, School of Pharmacy and Medical Sciences, University

of South Australia, as co-supervisor for the supervision, ideas and

discussions through this project.

• A/Prof Dzuy Nguyen, School of Chemical Engineering, University of

Adelaide for permission to access Rheology Laboratory and viscometer

device.

• Andrew Wright, Leanne Redding, Jason Peak and the workshop for

assistance in the laboratory, construction and modification of apparatus;

Thana Deawwanich for guidance to operate viscometer apparatus; Gideon

Bani Kuncoro and Kan Li my colleagues, for support, motivation, and any

discussions in the office.

I would like to dedicate this thesis to my wife, Nanik Hasanah and my son, Nawfal

Adiva Purwanto.

I hope this thesis would provide a great contribution to the community and satisfy

with the expectations of the related people.

vi

Table of Contents

Declaration ii

Summary iii

Acknowledgment v

Table of Contents vi

List of Figures ix

List of Tables x

Nomenclature xv

1 INTRODUCTION 1

2 LITERATURE REVIEW 3

2.1 Rice Bran Oil (RBO) 3

2.2 Epoxidation Reaction 6

2.3 Hydroxylation Reaction 9

2.4 Synthesis of Polyol 11

2.5 Response Surface Methodology 12

2.6 Key Research Questions 13

2.7 Research Objectives 15

2.8 Significant/Contribution to the Discipline 15

3 MATERIALS and METHODS 18

3.1 Materials 18

3.2 Epoxidation Reaction 18

3.3 Hydroxylation Reaction 20

3.4 Epoxidation Test 21

3.4.1 Iodine Value Analysis 21

3.4.2 Oxirane Oxygen Content Analysis 22

3.5 Hydroxylation Test 23

3.5.1 Hydroxyl Value Analysis 23

3.5.2 Viscosity Analysis 24

4 EXPERIMENTAL RESULTS and DISCUSSION 25

4.1 Epoxidation of RBO - Acetic Acid as an Oxygen Carrier

(1st Study) 25

4.1.1 Experimental Design and Optimization of the

Epoxidation Reaction 25

vii

4.1.2 Statistical Analysis 27

4.1.3 Effects of Reaction Time and Temperature on

Reaction Conversion 30

4.1.4 Effect of Reaction Time and Temperature on

Oxirane Content 31

4.2 Epoxidation of RBO – Formic Acid as an Alternate

Oxygen Carrier (2nd

Study) 33


the Conversion 33

4.2.2 Reaction Kinetics 35


Oxirane Content 38

4.3 Hydroxylation of Epoxidized RBO (3rd

Study) 41

4.3.1 Experimental Design and Optimization of

the Hydroxylation Reaction 41

4.3.2 Statistical Analysis 42


Hydroxyl Value 45


Viscosity of Polyol 48

5 CONCLUSION 52

6 RECOMMENDATIONS FOR FUTURE RESEARCH 53

REFERENCES 54

Appendix A – Calculation of Epoxidation Reaction 58

Appendix B – Calculation of Hydroxylation Reaction 61

Appendix C – Epoxidation Using Acetic Acid as an Oxygen Carrier

(1st Study) 63

C.1 Experimental Design 63

C.2 Determination of Iodine Value and Conversion 65

C.3 Oxirane Content 66

C.4 Determination of the Optimal Condition 67

viii

Appendix D – Epoxidation Using Formic Acid as an Oxygen Carrier

(2nd

Study) 69

D.1 Determination of Iodine Value and Conversion 69

D.2 Reaction Kinetics 73

D.3 Oxirane Oxygen Content 80

Appendix E – Hydroxylation of Epoxidized Oil 84

E.1 Experimental Design 84

E.2 Determination of Hydroxyl Value 85

E.3 Determination of the Optimal Condition 88

E.4 Determination of the Viscosity of the Polyol Products 89

ix

List of Figures

Figure 2-1 Structure of rice kernel 4

Figure 2-2 An epoxide 7

Figure 2-3 Epoxidation reaction 7

Figure 2-4 Ring opening mechanism using acid catalyst 10

Figure 2-5 Ring opening mechanism using base catalyst 10

Figure 2-6 Epoxidation reaction mechanism 11

Figure 2-7 Hydroxylation reaction mechanism 12

Figure 3-1 Experimental apparatus of epoxidation reaction 19

Figure 3-2 Experimental apparatus of hydroxylation reaction 20

Figure 4-1 Effects of reaction time (X1) and temperature(X2) on

reaction conversion for acetic acid as an oxygen carrier 30

Figure 4-2 Effects of reaction time (X1)and temperature (X2) on

oxirane content for acetic acid as an oxygen carrier 32

Figure 4-3 Effects of reaction time (t) on reaction conversion (X) for

formic acid as an oxygen carrier at different temperatures 34

Figure 4-4 Determination of activation energy for epoxidation using

formic acid as an oxygen carrier 37

Figure 4-5 Effects of reaction time (t) and temperature on oxirane content

(%) for formic acid as an oxygen carrier at different temperatures 39

Figure 4-6 Effects of reaction time (X1) and temperature (X2) on

hydroxyl value of polyol 46

Figure 4-7 Effects of reaction time (X1) and temperature (X2) on

viscosity of polyol 49

Figure 4-8 Sample of polyol produced 50

Figure D-1 Plot reaction time vs ln1/(1-X) at T = 40oC 75





Figure D-6 Plot ln(k) vs 1/T 80

x

List of Tables

Table 2-1 Typical fatty acid composition (wt%) of RBO 6

Table 2-2 Physical and chemical characteristics of RBO 6

Table 4-1 The range and levels of variables used in the RSM procedure

to determine the optimum conditions for the epoxidation reaction

of RBO 26

Table4-2 CCD and response in terms of conversion and oxirane content

during the epoxidation of RBO 27

Table 4-3 Regression statistics for conversion and oxirane content

for epoxidation of RBO 28

Table 4-4 Analysis of variance (ANOVA) for conversion and

oxirane content for epoxidation of RBO 28

Table 4-5 Significance of regression coefficients for conversion of

epoxidation of RBO 29

Table 4-6 Significance of regression coefficients for oxirane content

of epoxidation reaction 29

Table 4-7 Rate constant value at different temperature for

epoxidation using formic acid 36

Table 4-8 The range and levels of variables for hydroxylation reaction 42

Table 4-9 CCD and response in terms of hydroxyl value and


Table 4-10 Regression statistics for hydroxyl value and viscosity of polyol 44

Table 4-11 Analyses Of Variance (ANOVA) for hydroxyl value and


Table 4-12 Significance of regression coefficients for hydroxyl value of polyol 44

Table 4-13 Significance of regression coefficients for viscosity of polyol 45

Table A-1 Fatty acid composition of rice bran oil 58

Table C-1 Range and levels of variables 64

Table C-2 Experimental design of epoxidation using acetic acid

as an oxygen carrier 64

Table C-3 Experimental results of iodine value & conversion 66

Table C-4 Experimental results of oxirane oxygen content 67

xi

Table D-1 Experimental results of Iodine Value (IV) and Conversion (%X)

at 40oC 71


at 50oC 72


at 60oC 72


at 70oC 72

Table D-5 Experimental Results of Iodine Value (IV) and Conversion (%X)

at 80oC 72

Table D-6 Determination of k value at 40oC 75





Table D-11 Calculation of activation energy 79

Table D-12 Experimental results of oxirane oxygen content at T = 40oC 82





Table E-1 Range and levels of hydroxylation reaction 85

Table E-2 Experimental design of hydroxylation reaction 85

Table E-3 Saponification value prior to acetylation 86

Table E-4 Saponification value after acetylation 87

Table E-5 Hydroxyl value of polyol 88

Table E-6 Viscosity at shear rate 149.79 s-1

, t = 120 min and T = 30oC 90


, t = 120 min and T = 30oC 90


, t = 120 min and T = 30oC 91


, t = 120 min and T = 30oC 91


, t = 120min and T = 30oC 91


, t = 120 min and T = 30oC 92


, t = 120 min and T = 30oC 92


, t = 80 min and T = 40oC 93

xii


, t = 80 min and T = 40oC 93


, t = 80 min and T = 40oC 93


, t = 80 min and T = 40oC 94


, t = 80 min and T = 40oC 94


, t = 80 min and T = 40oC 94


, t = 80 min and T = 40oC 95


, t = 160 min and T = 40oC 96


, t = 160 min and T = 40oC 96


, t = 160 min and T = 40oC 96


, t = 160 min and T = 40oC 97


, t = 160 min and T = 40oC 97

Table E-25 Viscosity at shear rate 55.00s-1

, t = 160 min and T = 40oC 97


, t = 160 min and T = 40oC 98


, t = 40 min and T = 50oC 99


, t = 40 min and T = 50oC 99


, t = 40 min and T = 50oC 99


, t = 40 min and T = 50oC 100


, t = 40 min and T = 50oC 100


, t = 40 min and T = 50oC 100


, t = 40 min and T = 50oC 101


, t = 120 min and T = 50oC 102


, t = 120 min and T = 50oC 102


, t = 120 min and T = 50oC 102


, t = 120 min and T = 50oC 103


, t = 120 min and T = 50oC 103


, t = 120 min and T = 50oC 103


, t = 120 min and T = 50oC 104


, t = 200 min and T = 50oC 105


, t = 200 min and T = 50oC 105


, t = 200 min and T = 50oC 105


, t = 200 min and T = 50oC 106


, t = 200 min and T = 50oC 106


, t = 200 min and T = 50oC 106


, t = 200 min and T = 50oC 107

xiii


, t = 80 min and T = 60oC 108


, t = 80 min and T = 60oC 108


, t = 80 min and T = 60oC 108


, t = 80 min and T = 60oC 109


, t = 80 min and T = 60oC 109


, t = 80 min and T = 60oC 109


, t = 80 min and T = 60oC 110


, t = 160 min and T = 60oC 111


, t = 160 min and T = 60oC 111


, t = 160 min and T = 60oC 111


, t = 160 min and T = 60oC 112


, t = 160 min and T = 60oC 112


, t = 160 min and T = 60oC 112


, t = 160 min and T = 60oC 113


, t = 120 min and T = 70oC 114


, t = 120 min and T = 70oC 114


, t = 120 min and T = 70oC 114


, t = 120 min and T = 70oC 115


, t = 120 min and T = 70oC 115


, t = 120 min and T = 70oC 115


, t = 120 min and T = 70oC 116


, t = 120 min and T = 50oC 117


, t = 120 min and T = 50oC 117


, t = 120 min and T = 50oC 117


, t = 120 min and T = 50oC 118


, t = 120 min and T = 50oC 118


, t = 120 min and T = 50oC 118


, t = 120 min and T = 50oC 119


, t = 120 min and T = 50oC 120


, t = 120 min and T = 50oC 120


, t = 120 min and T = 50oC 120


, t = 120 min and T = 50oC 121


, t = 120 min and T = 50oC 121


, t = 120 min and T = 50oC 121

xiv


, t = 120 min and T = 50oC 122

xv

Nomenclature

E activation energy (kJ/mol)

k reaction rate constant (h-1

)

m mass (g)

n reaction orders

n moles number (mol)

N normality (N)

R gas constant (J/mol.K)

R2 correlation coefficient

SA saponification value after acetylation (mg KOH/g oil)

SB saponification value before acetylation (mg KOH/g oil)

t reaction time (h, for epoxidation reaction)

t reaction time (min, for hydroxylation reaction)

T temperature (K)

V volume (mL)

x real value of independent variables

X coded value of independent variables

X reaction conversion

Y response variables

Greek

x∆ step change value

ρ density (g/mL)

τ shear stress (Pa)

•

γ shear rate (s-1

)

µ viscosity (cP)

Abbreviations

ANOVA analysis of variance

DB double bonds

EO epoxidized oil

FA formic acid

xvi

FFA free fatty acids

HV hydroxyl value

IV iodine value

MMT million metric tons

MW molecular weight

PFA peroxyformic acid

PL phospholipids

PPO polypropylene oxide

RBO rice bran oil

RSM response surface methodology

US united states

1

1 INTRODUCTION

Polyurethanes were first discovered by Professor Otto Bayer in 1973 and are used in

a wide variety of applications (Chian et al., 1998). They have been exploited as

coatings, thermoset and thermoplastic materials, adhesives and rigid or non-rigid

foams (Guo et al., 2006; Lligadas et al., 2006; Wang et al., 2009). Hence, the

worldwide demand for polyols is projected to increase each year. Polyurethanes are

generally produced from the reaction between polyols and diisocyanate (Pechar et

al., 2006). Polyols are normally derived from petroleum feedstocks and are known

as petroleum-based polyols (Tu et al., 2007). As the demand for polyols is

increasing whilst the amount of petroleum is declining, alternative raw material for

the production of polyols are needed.

Worldwide rice production is roughly 500 million metric tons (MMT) per year

(Jahani et al., 2008). Rice bran oil (RBO) is a by product of the rice milling process;

hence it cheap and readily available. RBO is a potential raw material that has not

been explored as feedstock to produce polyol. RBO is attractive as it contains

unsaturated bonds that can be converted to hydroxyl groups called polyols. Hence,

RBO can be used as a raw material for polyol production. To date, rice bran has

been used as a mixture of livestock food and as biomass fuel for boiler feed. The oil

content of RBO is in the range of 15 – 23 wt% (Zullaikhah et al., 2005). Hence,

RBO has enormous potential as it is a renewable resource and research needs to be

undertaken to develop and add value by converting the double bonds present in

RBO to produce polyols. Moreover, the production cost of polyols could be reduced

with the utilization of such by products and low priced feedstock.

Polyol can be produced by two consecutive reactions, namely epoxidation and

hydroxylation (Petrovic et al., 2003). During the epoxidation stage, the double bonds

in the vegetable oils are converted into epoxide (oxirane) groups whereas in the

hydroxylation stage, the epoxide groups are converted to hydroxyl groups. The

resulting product is a polyol as it contains more than one hydroxyl groups.

2

In the epoxidation of rubber seed oil using peroxyacetic acid, the ring opening of

epoxide groups could be minimized when the epoxidation reaction was carried out at

an intermediate temperature of 50 – 60oC. (Okieimen et al., 2002). In the

epoxidation of soybean oil using peroxyacetic acid followed by hydroxylation

reaction using methanol, the hydroxyl value of soy-polyol of 169 mg KOH/g oil

could be achieved whereas using olive oil as a raw material and m-

chloroperoxybenzoic acid, the hydroxyl value of polyol product was 138 mg KOH/g

oil (Petrovic et al., 2003). However, far too little attention has been paid to the

utilization of RBO as a potential raw material to produce polyol. Therefore, in the

synthesis of polyol from RBO, the optimal operating conditions in the epoxidation

and hydroxylation reactions have to be clearly defined to obtain a high quality of

polyol since different raw materials will have different characteristics. High quality

of polyol is indicated by high content of hydroxyl groups represented by hydroxyl

value.

The key goal of this project is to determine the optimal operating conditions for the

epoxidation and hydroxylation reactions to produce a polyol synthesized from rice

bran oil.

3

2 LITERATURE REVIEW

This review will be divided into several parts. As mentioned in Chapter 1, the

composition of potential feedstock is a crucial factor for the successful synthesis of

polyol. Therefore, the first section will examine the potential of rice bran oil (RBO)

as raw material for synthesis of polyol. The next section will consider the synthesis

of polyol using epoxidation and hydroxylation reactions. As these reactions have

strong influence on the quality of polyol product, a review on epoxidation and

hydroxylation reactions will help to understand the process and contribution to

polyol product. Following this, response surface methodology (RSM) will be

discussed as a method to determine the optimal operating condition. Finally,

research questions, objectives and significance of this research will be discussed as

research direction and contribution of research topic to field area.

2.1 Rice Bran Oil (RBO)

Nowadays, polyol plays an important aspect as a raw material to produce

polyurethanes which have been widely used in polymer applications (Guo et al.,

2000, Hu et al., 2002, Lligadas et al., 2006, Wang et al., 2007). The demand for

polyol worldwide is predicted to increase each year. Generally, polyols are produced

from petroleum feedstocks. In recent years, interest has increased in the utilization

of vegetable oils as feedstock given environmental concerns and diminished

availability of raw materials for polyol production. Therefore, a number of

researchers have studied vegetable oils as alternative feedstock to substitute for

petroleum to provide sustainable development (Chen et al. 2002; Okieimen et al.,

2002; Petrovic et al., 2002 and 2003; Goud et al., 2006 and 2007; Setyopratomo et

al., 2006; Dinda et al., 2007; Benaniba et al., 2007; Ikhuoria et al., 2007; Lin et al.,

2008; Cai et al., 2008; Mungroo et al., 2008). One type of vegetable oils that can be

utilized as an alternative feedstock is rice bran oil (RBO). Hence, it needs to be

explored for various applications in particular polymer materials.

The term rice bran oil refers to the oil that comes from rice bran (Oryza sativa)

through an extraction process. Rice bran is a by product of rice milling process

4

produced from the outer layer of rice kernel or during conversion of brown to white

rice. The rice kernel consists of endosperm, 70 – 72%; hull, 20%; bran, 7.0 – 8.5%;

and embrio, 2- 3% (Ju et al. 2005). The structure of rice kernel is illustrated in

Figure 2-1 below:

Figure 2-1 Structure of rice kernel (source www.ricebranoil.info)

Rice bran oil is widely used as cooking oil in numerous countries, in particular in

Indonesia, China, Japan, India and Korea. These countries have attractive and

productive agriculture especially for rice cultivation. Therefore, RBO is readily

available and develops for edible oil in food processing application since it offers

benefit for healthiness and rich on nutrition. RBO has different characteristic

compared to other oils in terms of its unsaponifiable matter.

Rice bran is a by product from the rice milling process. It is normally used as

biomass fuel for boilers or as a food source for animals. Therefore, effort is needed

to increase the added value of rice bran by extracting the oil content as it contains oil

in the range 15 – 23% (Zullaikhah et al., 2005). RBO can be utilized as a potential

raw material for synthesis of polyol since it contains double bond, readily available

and inexpensive raw material. The typical composition of RBO by weight percent

(wt%) is (Ghosh, 2007):

• Triglycerides : 81 – 84%

• Diglycerides : 2 – 3%

• Monoglycerides :1 – 2%

• Free fatty acids (FFA) : 2 – 6%

• Wax : 3 – 4%

• Glycolipids : 0.8%

a1172507

Text Box

NOTE: This figure is included on page 4 of the print copy of the thesis held in the University of Adelaide Library.

5

• Phospholipids (PL) : 1 – 2%

• Unsaponifiable matter : 4%

The unsaturated fatty acid content in the oil is an important factor for synthesis of

polyol as the double bonds are converted to polyol. The unsaturated fatty acid

content is quantified by the iodine value as the double bonds adsorb iodine to form

saturated compounds. The amount of iodine adsorbed indicates the number of

double bonds hence unsaturated fatty acid concentration in the oil. In broad

chemical terms, iodine value can be defined as the amount of iodine (grams)

adsorbed by 100 grams of oil or fat (Ketaren, 2005). Potential vegetable oils for use

as raw material to produce polyol must posses an iodine value in the range of 80 to

240 gram I2/100 gram oil to be economic. Vegetable oils with lower iodine values

will produce polyol with a very low hydroxyl value. Therefore, the iodine value of

feedstock is the key determinant of suitability for polyol synthesis (Petrovic et al.,

2003). RBO is a potentially attractive feedstock that can be used as a raw material

for polyol production because it has high content (about 74%) of unsaturated fatty

acids (oleic and linoleic acid) and an iodine value of 99.9 gram I2/ 100 gram oil.

The composition, physical and chemical characteristics of RBO are primarily

determined by soil conditions in the growing area. For example, the iodine value of

RBO produced from a rice plant in Texas was 102.3 gram I2/100 gram oil, whereas

RBO extracted in North America States has an iodine value 99.9 gram I2/100 gram

oil. Table 2.1 provides a typical chemical composition of RBO measured by

Jamieson (in Bailey, 1951) whereas Table 2.2 provides the physical and chemical

characteristic of RBO. Both tables are derived from rice cultivated in the Northern

US (Bailey, 1951). Saponification value indicates the amount of potassium

hydroxide (milligrams) required to saponify 1 gram oil or fat (Ketaren, 2005). In

addition, acid value shows the amount of potassium hydroxide (milligrams) required

to neutralize free fatty acid in 1 gram oil or fat (Ketaren, 2005).

6

Table 2-1 Typical fatty acid composition (wt %) of RBO (Bailey, 1951)

Saturated fatty acid Composition

Myrictic acid (C14H28O2) 0.5 %

Palmitic acid (C16H32O2) 11.7 %

Stearic acid (C18H36O2) 1.7 %

Arachidic acid (C20H40O2) 0.5 %

Lignoceric acid (C24H48O2) 0.4 %

Unsaturated fatty acid Composition

Oleic acid (C18H34O2) 39.2 %

Linoleic acid (C18H32O2) 35.1 %

Unsaponifiable matter 4.64%

Table 2.2 Physical and chemical characteristics of RBO (Bailey, 1951)

Parameters Values

Iodine value 99.9 g I2/100 g oil

Saponification value 185.3 mg KOH/g oil

Acid value 73.7 mg KOH/ g oil

2.2 Epoxidation Reaction

The use of modified plant oils as a renewable feedstock in the chemical industry has

become more desirable. In particular, epoxidized fatty acid derivatives derived from

vegetable oil sources may be utilized as stabilizers and plasticizers in polymers, as

lubricant additives and as an intermediate product in the synthesis of polyol as

constituents of urethane foam. The utilization of epoxidized oil has become more

common over the past few years as such epoxidized oil derived from vegetable oils

is environmentally friendly (Wu et al., 2000). Moreover, plasticizers and additives

for polymer PVC derived from vegetable oil-based have been shown to have

improved performance in terms of high resistance to heat and light (Gan et al.,

1995).

7

epoxidation

The term epoxidized oil is generally understood to denote an oil that is derived from

vegetable oils using the epoxidation reaction. Epoxidized oil contains epoxide

groups or oxirane rings. The term epoxide may be defined as cyclic ethers which

consist of three elements in the epoxide ring. The term oxirane is also usually used

to refer to epoxide according to categorization by IUPAC (Solomons, 1992). The

chemical structure of epoxide according to Solomons (1992) can be illustrated as

follows:

C C

O

Figure 2-2 An epoxide

The general process for synthesis of epoxide groups is known as an epoxidation

reaction wherein an alkene is reacted with an organic peroxy acid. The term peracid

is frequently used and refers to a peroxy acid. The simplified epoxidation reaction is

summarized as follows (Figure 2-3):

O O

R1CH = CHR2 + R’COOH R1HC CHR2 + R’COH

O

Alkene Peroxy acid Epoxide

(or oxirane)

Figure 2-3 Epoxidation reaction

The epoxidation reaction is an important step in the synthesis of polyol. It plays a

key role in contributing to the final hydroxyl groups because epoxide groups will be

converted to hydroxyl groups. A number of studies have shown that a variety of

vegetable oils such as linseed oil, rubber seed oil, mahua oil, karanja oil, soybean

oil, canola oil, cottonseed oil, sunflower oil, corn oil, jatropha oil and methyl esters

of parkia biglobosa seed oil can be used in the epoxidation reaction to produce

epoxidized oils (Chen et al., 2002, Okieimen et al., 2002; Petrovic et al., 2002; Goud

et al., 2006 and 2007; Ikhuoria et al., 2007; Dinda et al., 2007; Benaniba et al., 2007;

Cai et al., 2008; Mungroo et al., 2008). This is due to their high percentage of

8

unsaturated bonds (indicated by high iodine values). For example, soybean oil has

the iodine value of 125 g I2/100 g oil while mahua oil with the iodine value 88 g

I2/100 g oil. In these studies, various factors influencing the kinetics of the

epoxidation step were investigated and are discussed below.

In Okieimen et al’s study (2002), epoxidation reaction by utilizing rubber seed oil as

a raw material to produce epoxidized rubber seed oil was investigated. The influence

of mole ratio of acetic acid and hydrogen peroxide to the oil and the temperature

versus the percentage oxirane oxygen content of epoxidized oil during the

epoxidation reaction were discussed. They concluded that the concentrations of

acetic acid as an oxygen carrier and hydrogen peroxide as an oxidizing agent have a

positive effect in term of increasing the formation of epoxide groups. It was also

reported that the ring opening of oxirane groups could be minimized when the

reaction was carried out at an intermediate temperature range (50 – 60oC). One of

the limitations of this paper is that it did not discuss the mole ratio of unsaturated

bonds in the oil to hydrogen peroxide or acetic acid.

A study of the epoxidation of soybean oil was conducted by Petrovic et al. (2002).

Their results indicated that at higher temperature (80oC), acetic acid is more

effective as an oxygen carrier than formic acid to attain high oxirane oxygen

content, whereas formic acid was more effective than acetic acid if the epoxidation

reaction was performed at 40 and 60oC. In this study, Petrovic et al. (2002) also

investigated the reaction kinetics for epoxidation by determining the rate constant

and activation energy.

An investigation of the epoxidation reaction of mahua oil using hydrogen peroxide

was performed by Goud et al. (2006). They studied the influence of various factors

including catalyst type, temperature, molar ratio of reactant and mixing speed on the

epoxidation reaction. They concluded sulfuric acid is the best catalyst for the

epoxidation reaction producing a high conversion of double bonds to oxirane groups

when the epoxidation reaction was performed at an intermediate temperature of 55-

65oC to reduce the hydrolysis reaction. In this work, they reported that the economic

value of mahua oil could be increased by converting the oil to an epoxidized mahua

oil.

9

In 2006, Goud et al. investigated the possible use of karanja oil as a feedstock to

produce epoxidized oil. They found that at intermediate temperature in the range of

55 to 65oC the conversion of double bonds to oxirane groups was optimal and the

reaction time was minimized. It was further also reported that a molar ratio of acetic

acid to karanja oil is 0.5 mole and a mole ratio of 1.5 for hydrogen peroxide to oil

was the optimal concentration for epoxidation of karanja oil. However, this study

would have been much more interesting had the authors included the steps in

determining the reaction kinetics.

A previous study by Purwanto et al. (2006) reported that at temperatures of 60oC

and higher, the hydroxyl value of the polyol product decreased with reaction time.

Hence, a temperature of 60oC and 4 h reaction time is the optimal condition for

epoxidation of soybean oil as it has produced polyol with highest content of

hydroxyl value of 151.1 mg KOH/g oil. In addition, this research results in polyol

viscosities in the range of 59.3 to 78.0 centipoises.

Dinda et al. (2008) recently synthesized epoxidized oil from cottonseed oil using

hydrogen peroxide and inorganic acids as a catalyst. These workers reported that the

optimal operating conditions were achieved if the epoxidation reaction was

performed using H2SO4 (best catalyst) at a concentration approximately 2% by

weight, using a mole ratio of hydrogen peroxide to oil in the range 1.5 – 2.0, a mole

ratio of acetic acid as an oxygen carrier to oil of 0.5 at temperatures in the range of

50 – 60oC. Using these conditions, a high content of oxirane groups was achieved

and degradation of oxirane ring was minimized.

2.3 Hydroxylation Reaction

Throughout this research report, the term hydroxylation reaction is used to refer to

the process of introducing hydroxyl groups into unsaturated bonds to the oil. There

are various sources of hydroxyl groups that can be used in the hydroxylation process

such as alcohols and water. Before the hydroxylation reaction occurs, the oxirane

ring must be opened. There are two ways to open an oxirane ring to permit the

10

+H+

-H+

H-O-H

+

-H+ +

ROH

hydroxylation reaction to occur. Firstly, ring opening using acid catalyst is

performed (Solomon, 1992). The mechanism of this process can be described as:

C C C C

O O

H

HO C C O H HO C C OH

H

Figure 2-4 Ring opening mechanism using acid catalyst

Another pathway to open oxirane ring uses a base catalyst (Solomon, 1992). The

mechanism of this process is as follows:

RO:- + C C RO C C O- RO C C OH + RO:-

O

Figure 2-5 Ring opening mechanism using base catalyst

A number of studies have found that the hydroxylation reaction is a crucial step in

the synthesis of polyol since it also contributes to the hydroxyl value of polyol by

introducing hydroxyl groups into the oxirane groups (Petrovic et al., 2003;

Setyopratomo et al., 2006; Guo et al., 2006; Lin et al., 2008). They investigated

various epoxidized vegetable oils as raw materials to produce polyols such as

epoxidized soybean oil, safflower oil, sunflower oil, canola oil, corn oil, olive oil

and peanut oil. A variety of factors that may influence in the hydroxylation were

also studied for process optimization.

Extensive work on the hydroxylation of epoxidized oil was undertaken by Petrovic

et al. (2003). In this study, they found that the ratio of alcohol and water to vegetable

oils in the mixture of alcohol and water is important for success in the hydroxylation

reaction. Groups of alcohol that can be used for hydroxylation reaction include

methanol, ethanol, n-propanol, isopropanol and n-butanol. The study would have

11

been more convincing if they had included the influence of temperature and reaction

time on the quality of polyol product.

Kinetic studies of oxirane degradation using methanol have been investigated by Lin

et al. (2008). They were able to produce polyol by reacting epoxidized soybean oil

and methanol without any catalyst in the mixture. The result indicated that

hydroxylation of epoxidized soybean oil was first and second order to the

concentration of epoxidized oil and methanol concentration, respectively. It is

envisaged that the hydroxylation reaction would have been faster had they used

catalyst to open the oxirane ring by using either an acid or base catalyst.

The comparison of performance of acid and base catalysts that influence the

hydroxyl value of polyol products has been investigated for the hydroxylation of

palm oil (Setyopratomo et al., 2006). An acid catalyst represented by H2SO4 shows

better performance than a base catalyst represented by NaOCH3 indicated by a

higher content of hydroxyl groups. The optimal operating condition using acid

catalyst was achieved at temperature of 50oC and 2 h reaction time.

2.4 Synthesis of Polyol

From the previous section, it is clear that polyol can be synthesized from vegetable

oils that contain unsaturated bonds through two consecutive steps involving

epoxidation and then hydroxylation reactions. In the epoxidation step, the reaction

mechanism can be described as follows (Okieimen et al., 2002):

1. Formation of peroxyacid:

RCOOH + H2O2 RCOOOH + H2O

2. Epoxidation reaction:

R1CH=CHR2 + RCOOOH R1CH CHR2 + RCOOH

O

Figure 2-6 Epoxidation reaction mechanism

12

In the hydroxylation step, the reaction mechanism can be depicted below (Purwanto

et al., 2006):

1. Reaction of epoxidized oil with water:

R1CHOCHR2 + H2O R1-CH-CHR2

OH OH

2. Reaction of epoxidized oil with alcohol:

R1CHOCHR2 + R3OH R1-CH-CHR2

R3O OH

Figure 2-7 Hydroxylation reaction mechanism

A variety of research studies have been undertaken using various raw materials to

synthesize polyol. So far, however, there has been little discussion about the

synthesis of polyol from rice bran oil (RBO). In fact, RBO is a cheap and readily

available by product and waste in the milling rice process which has high content of

unsaturated bonds. Thus, it is our belief that the synthesis of polyol from RBO needs

to be explored.

2.5 Response Surface Methodology

Response surface methodology (RSM) is method for performing process

optimization using mathematics and statistics to construct a model of the process to

determine the optimal process conditions (Myers, et al., 1995; Montgomery, 2005).

The relationship between independent variables (x) and dependent (response)

variables (y) is usually unknown and complex and RSM is applied to determine an

estimation equation that represents closely the relationship between x and response

variables (y). For ease of application, a low-order polynomial model is normally

employed to represent estimation function. The first order model is the simplest

model employed (Equation 2-1):

εββββ +++++= kk xxxy ...22110 (2-1)

or second order model (Equation 2-2):

εββββ ∑ ∑∑∑==

++++=k

i

jiijiii

k

i

ii xxxxy1

2

1

0 (2-2)

13

The next step is to perform an experimental design and then this step is followed by

data analysis. The actual values of variables are normally expressed in coded values

for analysis. The coded value is given by equation (2-3):

i

i

ix

xxX

∆

−= 0 (2-3)

Where: iX = the coded value of an independent variable

ix = the real value of an independent variable

0x = the real value of an independent variable at the centre point

ix∆ = the value of step change

Following this, the range and level of variables is determined to indicate scope of

variables includes the experimental design to determine the model parameters. The

fitted surface is then employed to analyze the response surface. If the resulting

response surface is statistically a good fit then the response surface will be a close

approximation of the real system.

Application of RSM for process optimization is a commonly used strategy. The

developed model can be easily maximized or minimized to determine the best

response variables. Thus in process optimization of a particular chemical process,

RSM can determine the optimal operating condition and offer benefits such as

reduced experimental time, a less complexity, and highly efficient process.

2.6 Key Research Question

Over the last a few decades, polyol derived from petroleum oil as feedstock has been

used to produce polyurethane to fulfill the world’s needs for this polymer. Recently,

a number of studies have been conducted to investigate the use of vegetable oils as a

renewable and sustainable feedstock to replace the use of petroleum oil. Many

researchers have concluded that vegetable oil can be exploited as an alternative raw

material to substitute for petroleum oil to produce polyol. Examples include soybean

oil, safflower oil, olive oil, canola oil, cottonseed oil, palm oil and rapeseed oil

(Petrovic et al., 2003). Vegetable oil – based polyol is a sustainable material which

14

can be efficiently produced through two-consecutive steps, epoxidation and

hydroxylation reactions. Rice bran oil is a potential feedstock source.

The unsaturated fatty acid content in RBO is indicated by its iodine value. RBO with

an iodine value of 99.9 g I2/100 g oil has 74.3% of total unsaturated fatty acid (oleic

and linoleic acid) in the oil (Bailey, 1951). A key criterion to economically produce

polyol is to use vegetable oil with an iodine value in the range of 80 to 240 to

accomplish high hydroxyl value and consequently allow production high viscosity

of polyol product (Petrovic et al., 2003). To date, the normal route to produce polyol

is by converting unsaturated bonds in the oil in a two step process using epoxidation

followed by hydroxylation reactions.

Research conducted by Purwanto et al. (2006) and Lin et al. (2008) has shown that

the epoxidation and hydroxylation reactions contribute to hydroxyl value of the final

product of polyol. In the epoxidation step, unsaturated bonds in RBO are converted

to produce epoxy groups indicated by the percentage of oxygen content. A high

percentage of oxygen content in the epoxidized oil has more epoxy groups.

Therefore, this research investigated the influence of the reaction time, reaction

temperature and type of peroxy acid (peroxyacetic acid and peroxyformic acid) as

oxygen carrier in order to determine the optimal operation conditions in the

epoxidation reaction.

In the hydroxylation step, the epoxy groups in the epoxidized oil are converted to

form hydroxyl groups called polyol. A good quality of polyol is indicated by a high

hydroxyl value. Therefore, intensive research needs to be conducted to investigate

key process variable in the hydroxylation step that influence the final quality of the

product of polyol. In other words, the optimum operating conditions in the

hydroxylation step also need to be quantified, such as reaction time and temperature

to attain high quality of polyol products synthesized from rice bran oil.

15

2.7 Research Objectives

This study is divided into two steps. The first step deals with the determination of

optimal operating conditions in the epoxidation step in terms of reaction time and

temperature. The aims of the first step in this study are:

• to investigate the optimal operating condition in the epoxidation step using

acetic acid and formic acid as oxygen carriers (peroxyacetic and

peroxyformic acid respectively) to attain epoxidized oil with high oxygen

content.

• to determine the reaction kinetics in the epoxidation step using formic acid as

an oxygen carrier (peroxyformic acid).

• to compare the performance of acetic acid and formic acid as oxygen carriers

in the epoxidation step in converting double bonds to epoxy groups.

The optimum operating conditions obtained in the epoxidation step will be used to

generate epoxidized oil samples for the next step.

The second stage of this research considers the determination of the optimal

operating conditions in the hydroxylation step for the synthesis of polyol. The aim of

the second step in this study is to investigate the optimal reaction time and

temperature in the hydroxylation step to attain polyol of high quality indicated by a

high content of hydroxyl value with a reasonable viscosity. At present there is no

fixed specification for polyol viscosity.

2.8 Significant/Contribution to the Discipline

Vegetable oil particularly rice bran oil (RBO) is an alternative raw material to

produce polyol for the next generation. This is important since it can lessen the

world’s reliance on petroleum oil and the limited amount of non-renewable

resources can be saved as a heritage for future generations. Polyol derived from

vegetable oil could overcome the problem in the application of polyol derived from

petroleum since polypropylene oxide (PPO) triols derived from petroleum oil tend to

undergo oxidation processes, thus these materials are rather unstable. By contrast,

polyol from vegetable oils are resistant to oxidative degradation. Other benefits of

16

polyurethanes produced from vegetable oil based-polyol are stability under thermal

stress and improved dielectric properties (Guo et al., 2000).

Over the past few decades, the world’s demand for polyurethanes has increased and

these polyurethane compounds can also be produced from vegetable oils (John et al.,

2002). Therefore, the use of RBO in particular, could increase the economic value of

RBO. Furthermore, the availability of RBO as a raw material can be guaranteed

since RBO-oil is a renewable resource. A high content of unsaturated bonds

indicated by high iodine value of RBO allows high yield of hydroxyl groups, a key

requirement for economic production of RBO based polyols.

Epoxidation and hydroxylation reactions are crucial steps to produce a high quality

of polyol as indicated by a high hydroxyl value with reasonable viscosities. The

synthesis of polyol with the utilization of soybean oil, corn oil, safflower oil,

sunflower oil, canola oil, olive oil and peanut oil has been studied extensively by

Petrovic, Guo, and Javni (2003). However, there is significant lack of information

on the use of RBO as a starting material to produce polyol. As the epoxidation and

hydroxylation steps also contribute to the final product of polyol, the optimum

operating conditions for reaction time and temperature in the epoxidation and

hydroxylation reactions must be determined. The best form of peroxy acid as

oxygen carrier (peroxyacetic acid or peroxyformic acid) in the epoxidation step must

also be investigated to determine the key parameters hydroxyl value and the

viscosity of polyol product. High grade polyols will have a high hydroxyl value with

reasonable viscosity.

Determination of the optimum operating conditions for polyol production in the

epoxidation and hydroxylation stages will result in a cheap, more efficient process.

Both reaction time and temperature have a close relationship with energy

consumption in the process hence, optimum reaction time and temperature could

prevent energy waste so that an efficient process could be attained. This could

produce many benefits such as reducing production cost and maximizing selection

process.

17

In addition, if we can use RBO as a raw material to produce polyol, it can save

petroleum as a non-renewable resource. This research can also support the

establishment of vegetable oil–based polyol industries. Hence, it will automatically

create more work opportunities and also contribute largely to the national economy.

Furthermore, this research can encourage and support other research to use

renewable natural resources. Therefore, this research generally can encourage the

creation of renewable natural resources-based industry.

18

3 MATERIALS and METHODS

The purpose of this research is as an initial study of the synthesis of polyol from rice

bran oil to increase its added value and to determine the optimal reaction conditions.

The two consecutive steps for the synthesis of polyol are epoxidation and

hydroxylation reactions. These reactions were investigated to determine the optimal

operating conditions in the epoxidation reaction using acetic acid and formic acid

where the oxygen carriers and the reaction kinetics using formic acid in the

epoxidation step and hydroxylation reaction are subjects of evaluation. Formic acid

was selected to study the reaction kinetics in the epoxidation step as the formation

rate of peroxyformic acid is faster than peroxyacetic acid (Kirk-Othmer

Encyclopedia of Chemical Technology, 1965). This chapter outlines the research

methods applied in this investigation.

3.1 Materials

The raw materials for this study of the epoxidation reaction were rice bran oil (Old

Fashioned Foods Ltd) which was purchased from a supermarket; glacial acetic acid

(Chem Supply); formic acid (Chem Supply); hydrogen peroxide 30 wt% (Ajax

Finechem); sulfuric acid 95 – 98 wt% (Ajax Finechem). Furthermore, methanol

(Chem Supply); isopropanol (Chem Supply); sulfuric acid 95 – 98 wt% (Ajax

Finechem); and water were used in the hydroxylation reaction.

3.2 Epoxidation Reaction

The epoxidation reaction was carried out in a 500 mL three neck flask batch reactor,

equipped with agitator, reflux condenser and thermocouple. The three neck flask

was immersed in a heating mantle whose temperature could be controlled to less

than ±2 K. A schematic of the experimental apparatus for the epoxidation reaction is

illustrated in Figure 3-1.

19

Notes:

A. Three neck flask

B. Mechanical stirrer

C. Condenser

D. Heating mantle

E. Retort and stand

F. Thermocouple

Figure 3-1 Experimental apparatus of epoxidation reaction

In order to meet the research objectives for the epoxidation step, two initial studies

were performed. The first study determined the optimal operating condition for the

epoxidation reaction as a function of reaction time and temperature using acetic acid

as the oxygen carrier (peroxyacetic acid). A response surface methodology (RSM)

was then performed to obtain the optimal operating condition for this epoxidation

reaction using peroxyacetic acid. The second study focused on determining the

optimal operating condition using formic acid as the oxygen carrier (peroxyformic

acid) and investigated the reaction kinetics. The optimal condition obtained from

epoxidation step in terms of oxygen carrier, reaction time and temperature was used

for the next step in the synthesis of polyols from RBO through epoxidation and

hydroxylation reactions.

Prior to the epoxidation reaction, RBO was analyzed to determine its initial iodine

value. The RBO was then used as the feedstock for the epoxidation stage. The

experimental method for the epoxidation step (adapted from Goud et al., 2007) is as

follows: rice bran oil (RBO) in the amount of 200 mL was placed in the 500 mL

three neck flask equipped with reflux condenser. Formic acid or acetic acid at a

molar ratio of 0.5:1 to the oil and sulfuric acid catalyst 3% weight of hydrogen

peroxide and oxygen carrier was added into RBO. A hydrogen peroxide molar ratio

20

of 1.5:1 to the oil was then added drop-wise into the mixture. This feeding strategy

was required to avoid overheating the system as the epoxidation reaction is highly

exothermic. The reaction was well mixed and was performed at a stirring speed of

1600 rpm under isothermal conditions at several temperatures and reaction times.

The product of the reaction was next cooled and decanted to effect a separation of

the organic-soluble compounds (epoxidized oil) from water-soluble phase. The

epoxidized oil was then washed with warm water (in small aliquots) to remove

residual contaminants. The product was then analyzed to determine its iodine value

and oxirane content.

3.3 Hydroxylation Reaction

The hydroxylation reaction was performed in a 1000 mL glass reactor, equipped

with stirrer, reflux condenser and thermocouple. The reactor was placed on a heating

plate with temperature control. A photograph of the experimental apparatus for

hydroxylation reaction is presented as Figure 3-2.

Figure 3-2 Experimental apparatus of hydroxylation reaction

21

As noted earlier in order to determine the optimal operating condition for the

hydroxylation step, the optimal condition obtained from epoxidation reaction was

applied to produce the epoxidized oil feedstock. Therefore, epoxidation reaction at

the optimal operating condition was followed by hydroxylation reaction. To meet

the research objectives of determining the overall optimal process conditions, the

optimal operating parameters for the hydroxylation reaction were investigated in

terms of reaction time and temperature. Then RSM was performed to deduce the

optimal operating condition in the hydroxylation reaction.

The procedure for hydroxylation reaction (adapted from Petrovic et al., 2003) is as

follows: 150 mL epoxidized oil was hydroxilated using a mixture of alcohols

(methanol and isopropanol), water and sulfuric acid as a catalyst. Mixture of alcohol

(methanol and isopropanol) with molar ratio of 4:1 to the oil each and water at molar

ratio of 2:1 were mixed with the epoxidized RBO and sulfuric acid catalyst in the

reactor. The reaction was performed at several fixed temperatures and reaction

times. The reaction product (polyol) was then washed with warm water (in small

aliquots) to remove contaminants and then decanted to effect a separation of the

organic-soluble compounds (polyol) from water-soluble ones. The resulting polyol

produced from the hydroxylation process was then analyzed using two key

parameters: the hydroxyl value and the viscosity of the product polyol. Again RSM

was performed to determine the optimal operating conditions for the hydroxylation

process.

3.4 Epoxidation Test

This section summaries the analysis methods used to evaluate yield from the

epoxidation reaction evaluation in terms of the two key variables, namely iodine

value and oxirane oxygen content.

3.4.1 Iodine Value Analysis

Iodine value was determined by applying the Wijs method (Ketaren, 2005; Siggia,

1963; Sudarmaji et al., 1997). The sequence of the procedure is as follows: 0.1 to 0.5

22

grams of sample were placed into the flask. 10 mL of chloroform was then added to

the sample. Following this, 15 mL Wijs iodine solution was added. Using the same

procedure, blank solution was also prepared. The mixture was then stored in a dark

place for at least 30 minutes at temperature of 25±5oC and after that, 10 mL of 15

wt% potassium iodide (KI) solution and 50 mL of water were added into the

mixture. The iodine content in the mixture was then titrated using 0.1 N sodium

thiosulfate solution until the yellow colour of the solution almost disappeared. A few

drops of starch indicator solution were then added and titration was continued until

the blue color completely disappeared. The iodine value was calculated using the

following equation:

Iodine value

( ) ( )

C

xNxAB 69.12−

= (3-1)

Where: A = Volume of Na2S2O3 solution required for titration of the sample (mL).

B = Volume of Na2S2O3 solution required for titration of the blank solution

(mL).

C = weight of sample (gram).

N = normality of Na2S2O3 solution.

3.4.2 Oxirane Oxygen Content Analysis

The oxirane content of the epoxidized oil must be quantified to determine the

conversion of unsaturated bonds in RBO to oxirane groups. The procedure (adapted

from Siggia, 1963) is as follows: a calculated amount of epoxidized oil was added

into a flask. 5 mL of ethyl ether was used to wash the flask side and then 10 mL of

the hydrochlorination reagent (0.2 N HCl in ethyl ether) was added into the flask.

Simultaneously, a blank solution was prepared using an identical procedure. The

mixture was then allowed to stand for 3 hours at room temperature. The mixture was

then titrated with standard 0.1 N sodium hydroxide solution. Prior to this, a few

drops of phenolphthalein indicator solution and 5 0mL of ethanol solution were

added. The percentage of oxirane content was calculated using the following

equation:

23

% oxirane oxygen content

( )

1000

10016

xW

xxNxVV sb −

= (3-2)

Where: bV = volume of NaOH used for blank (mL).

sV = volume of NaOH used for sample (mL).

N = normality of NaOH

W = weight of the sample (gram)

3.5 Hydroxylation Test

This section summaries the analysis techniques and methodology used for

evaluation of the hydroxylation step evaluation in terms of hydroxyl value and

viscosity.

3.5.1 Hydroxyl Value Analysis

The hydroxyl content of hydroxilated oil (polyol) must be determined as the

hydroxyl value of RBO based-polyol is a key measure of the quality of the resultant

polyol product. The procedure was adapted from the work of Ketaren (2005). Prior

to this, the saponification value of the sample must be determined before and after

the acetylation process. In the acetylation process, the hydroxyl groups in the oil are

converted to ester then analyzed in terms of their saponification value before and

after the acetylation process to determine the amount of hydroxyl groups.

In the acetylation process, 20 mL of oil sample was mixed with 20 mL of acetic

anhydride in a flask. The mixture was then boiled for 2 hours. Following this, 50 mL

of water was added into the mixture and the mixture was boiled for 15 minutes. It

was then cooled and washes water then used to effect a separation from the mixture.

After that, 50 mL of water was added and mixture was boiled for 15 minutes. This

procedure was repeated several times until the washing water was neutral. After the

washing water was separated, acetylated oil was dried over sodium sulfate

anhydrous and then filtered.

24

In the saponification process, a calculated amount of oil was placed into a flask. 20

mL of alcoholic potassium hydroxide (0.5 N) was then added into the flask and the

mixture was boiled to form saponificable oil. The mixture was then cooled and the

flask side was washed with little water. After that, a few drops of phenolphthalein

indicator were added and the mixture was then titrated with 0.5 N hydrochloric acid

solution until the red color entirely disappeared. Using the same procedure, a blank

solution was prepared and then titrated with hydrochloric acid solution. The

hydroxyl value of polyol was calculated using the following equation:

Saponification value

( )

G

xBA 05.28−

= (3-3)

Where: A = milliliters of 0.5N HCl required for blank solution.

B = milliliters of 0.5N HCl required for sample.

G = weight of the sample (g).

05.28 = a half value of molecular weight of KOH

Hydroxyl value ( )SA

SBSA

00075.01−

−= (3-4)

Where: SA = saponification value after acetylation process

SB = saponification value before acetylation process

3.5.2 Viscosity Analysis

The viscosity of RBO based-polyol were measured at 25oC using Brookfield

viscometer VT 550 connected to computer software. The procedure is as follows:

the computer connected to viscometer apparatus was turned on. Prior to turning on

the viscometer apparatus, the “job manager” in the computer program was opened.

After that, the polyol samples were filled in into the cup. Following this, the cup was

inserted into temperature control vessel and secured by screwing at the bottom. In

order to control temperature at 25oC, a water bath equipped with controller with a

fixed set point temperature in the water bath. Once the file job was opened on the

computer, the speed level was selected and then rotor started to rotate. The collected

data was checked in data manager and then changed into shear stress )(τ and shear

rate )(•

γ . The viscosity was measured as the ratio of shear stress and shear rate.

25

4 EXPERIMENTAL RESULTS and DISCUSSION

This section summarizes the results obtained from the experiments performed in the

laboratory. Specifically, it will discuss critically the synthesis of polyol from RBO

through epoxidation and hydroxylation steps. Hence, it is divided into three sections

consisting of epoxidation using acetic acid and formic acid as oxygen carriers

followed by hydroxylation of epoxidized oil to determine the optimal operating

conditions for the two stage involved in the synthesis of polyol from RBO.

4.1 Epoxidation of RBO - Acetic Acid as an Oxygen Carrier

(1st Study)

During the epoxidation reaction, double bonds in the oil are converted to oxirane

rings. Hence, the objective function for determining the optimal condition in the

epoxidation reaction using acetic acid as an oxygen carrier is to maximize the

amount of oxirane groups as indicated by a high amount of oxirane oxygen content.

Response surface methodology (RSM) provides an efficient experimental strategy to

study the influence of imposed variables to discover a final optimum condition

(Montgomery 2005, p. 405). Furthermore, RSM has additional benefits such as it

allows determination of interaction effects between variables (Wang et al., 2008)

and saves time as a reduced number of experiments are required (Doddapaneni et

al., 2007).

4.1.1 Experimental Design and Optimization of the Epoxidation

Reaction

Full factorial central composite design (CCD) was employed and the total number of

treatment combinations can be represented as 022 nkk ++ (Doddapaneni et al.,

2007).

Where: k2 = factorial design

k2 = star point

k = the number of independent variables

26

0n = the number of replications at the centre point

This first study evaluated the effect of two independent variables (reaction time and

temperature) of epoxidation reaction on the response variables (% conversion and %

oxirane content). The central values of the independent variables in the epoxidation

of RBO using acetic acid as an oxygen carrier were a batch reaction time of 4 hours

at a temperature of 60oC. The two independent variables to be optimized were coded

1X and 2X at five levels (-2, -1, 0, 1, 2) using the equation below:

i

i

ix

xxX

∆

−= 0 (4-1)





The distribution of coded 1X and 2X at five levels is indicated in Table 4-1. At this

stage, 4 points factorial design, 4 star points and 3 replicates at the central points (all

factors at level 0) were performed to fit with the second order polynomial model.

Hence, 11 experiments were conducted for the epoxidation of RBO using acetic acid

as an oxygen carrier.

Table 4-1 The range and levels of variables used in the RSM procedure to determine

the optimum conditions for the epoxidation reaction of RBO

Variables Symbol coded Range and levels

-2 -1 0 1 2

Reaction times (h)

Temperatures (oC)

1X

2X

2 3 4 5 6

40 50 60 70 80

27

4.1.2 Statistical Analysis

A second-order polynomial model (Equation 4-2) was fitted to represent the

experimental data presented in Table 4-2.

2112

2

222

2

11122110 XXXXXXY ββββββ +++++= (4-2)

Where )21( −=iYi is the response ( 1Y = % conversion and 2Y = % oxirane content);

0β is a constant; 1β and 2β represent the linear coefficients; whilst 11β and 22β are

the quadratic coefficients; 12β is the interaction coefficient.

Table 4-2 CCD and response in terms of conversion and oxirane content during the

epoxidation of RBO

Reaction time

(h)

Temperature

(oC)

Conversion

(%)

Oxirane

(%)

Exp. No.

1X 2X 1Y 2Y

1 -1 -1 50.5 1.69

2 1 -1 67.7 2.16

3 -1 1 67.7 2.48

4 1 1 81.4 2.32

5 -2 0 42.7 1.76

6 2 0 78.6 2.40

7 0 -2 23.7 1.65

8 0 2 88.0 2.20

9 0 0 67.7 2.61

10 0 0 65.2 2.62

11 0 0 65.5 2.58

Microsoft Excel was used to analyze the results in the form of an analysis of

variance (ANOVA).

For each reaction time and corresponding temperature, the conversion ( )1Y and

oxirane content ( )2Y were determined for the epoxidation process. The correlation of

the responses 1Y and 2Y to the coded values of variables was estimated using

28

multiple linear regression. The obtained regression coefficients are presented in

Table 4-3 and the analysis of variance (ANOVA) is provided as Table 4-4. Analysis

of regression statistics from the analysis of variance indicated a good fit and

reasonable significance F < 0.01.

Table 4-3 Regression statistics for conversion and oxirane content for epoxidation

of RBO

Regression statistics Conversion ( )1Y Oxirane content ( )2Y

Multiple R

R Square

Adjusted R Square

Standard Error

Observations

0.963

0.927

0.854

7.033

11

0.965

0.931

0.861

0.138

11

Table 4-4 Analysis of variance (ANOVA) for conversion and oxirane content for

epoxidation of RBO

Source DF SS MS F Significance F

Conversion

Oxirane

content

Regression

Residual

Total

Regression

Residual

Total

5

5

10

5

5

10

3146.0

247.3

3393.3

1.273

0.095

1.37

629.2

49.5

0.254

0.019

12.72

13.40

0.0072

0.0064

29

Table 4-5 Significance of regression coefficients for conversion of epoxidation of

RBO

Coefficients Standard Error t Statistic P-value

Intercept 68.079 3.608 18.870 7.7E-06a

1X 8.554 2.030 4.213 0.0084b

2X 13.294 2.030 6.548 0.0012b

2

1X -1.490 1.601 -0.931 0.3947

2

2X -2.694 1.601 -1.683 0.1532

21 XX -0.887 3.517 -0.252 0.8109

a Significant at 0.1% (p<0.001)

b Significant at 1.0% (p<0.01)

Table 4-6 Significance of regression coefficients for oxirane content of epoxidation

reaction


Intercept 2.543 0.0707 35.961 3.13E-07a

1X 0.132 0.0398 3.324 0.0209c

2X 0.170 0.0398 4.271 0.0079b

2

1X -0.127 0.0313 -4.043 0.0099b

2

2X -0.165 0.0314 -5.264 0.0033b

21 XX -0.161 0.0689 -2.336 0.0667



c Significant at 5.0% (p<0.05)

The model is a good fit of the experimental data as indicated by high values of the

correlation coefficients (R2) for the responses. The data analysis for regression was

undertaken using Microsoft Excel whereas Matlab plotting software was employed

to visualize the results.

30

4.1.3 Effects of Reaction Time and Temperature on Reaction

Conversion

The experimental data from the central composite design was fitted with a second-

order polynomial model by performing multiple linear regressions. The correlation

between conversions of iodine value 1Y and the two independent variables (reaction

time and temperature) in coded units after applying of response surface

methodology can be represented by equation:

21

2

2

2

1211 89.069.249.129.1355.808.68 XXXXXXY −−−++= (4-3)

Where 1Y (conversion of iodine value in %) is the response, and 1X and 2X are the

coded values of the independent variables (reaction time and temperature).

Figure 4-1 Effects of reaction time (X1) and temperature (X2) on reaction

conversion for acetic acid as an oxygen carrier

The result indicates that the conversion of iodine value in the RBO increases linearly

with the rise of reaction time and temperature, and at a faster rate with temperature

than with reaction time (Figure 4-1). These effects are positive and significant at p <

0.01 confidence level for both reaction time and temperature (Table 4-5).

31

Unsaturated double bonds present in the oil are converted to oxirane rings through

the epoxidation reaction as indicated by the decrease in the iodine value. This value

in the RBO represents the concentration of double bonds and it decreases with

reaction time (Petrovic et al., 2002). Therefore, the reaction conversion increases

with reaction time and temperature. These findings are also consistent for

epoxidation of cottonseed oil with those Dinda et al. (2008) who also reported a

similar behaviour.

4.1.4 Effect of Reaction Time and Temperature on Oxirane

Content

The empirical relationship between oxirane content and the two independent

variables (reaction time and batch temperature) in coded units is represented as:

21

2

2

2

1212 161.0165.0127.0170.0132.0543.2 XXXXXXY −−−++= (4-4)

The regression result (Table 4-6) shows that oxirane content in the RBO is a

quadratic function of reaction time and temperature. All the observed effects were

significant at p < 0.05 (Table 4-6). As can be seen from Figure 4-2, the amount of

oxirane content increases with reaction time and temperature and then that value

reaches the maximal level. Following this, the oxirane content decreases with

reaction time and temperature.

32

Figure 4-2 Effects of reaction time (X1) and temperature (X2) on oxirane content for

acetic acid as an oxygen carrier

There are two major reactions involved in the epoxidation reaction (Petrovic et al,

2002; Milchert et al., 2009). During the first stage, peroxyacetic acid is formed from

the reaction of acetic acid and hydrogen peroxide as summarized by:

CH3COOH + H2O2 CH3COOOH + H2O (4-5)

During the second stage, epoxidized oil is produced from the reaction between

peroxyacetic acid and double bonds in the oil, illustrated as:

CH3COOOH + CH CH CH CH + CH3COOH (4-6)

O

The maximum oxirane content was achieved at a reaction time (coded) 0.28 and at a

temperature (coded) 0.38 (Appendix C.4). These coded values were attained using

calculation to determine the function’s stationary points by taking partial derivatives

of the polynomial equation of oxirane content. The real values of variables at the

33

optimal condition was deduced by converting these coded values to the original

scale using equation (4-1) and the optimal condition for the epoxidation reaction

occurred with reaction time of 4.3 h at a batch temperature of 63.8oC. At higher

reaction time and temperature, the reaction results in lower oxirane content. This is a

result of a high temperature of epoxidation reaction favouring a high rate of oxirane

ring opening thereby producing a product with reduced oxirane content (Purwanto et

al., 2006). Therefore, higher side reaction products may be formed above the

optimal temperature such as reaction between oxirane rings and acetic acid or water

and a dimerization reaction may occur (Petrovic et al., 2002; Milchert 2009). These

findings are also consistent with those of Dinda et al. (2008) who found at higher

temperature (60oC or higher) the relative conversion to oxirane increased to an

optimal operating point and then declined gradually in the epoxidation of cottonseed

oil.

4.2 Epoxidation of RBO – Formic Acid as an Alternate Oxygen

Carrier (2nd

Study)

This section presents results and critical discussions for epoxidation using formic

acid as an oxygen carrier (peroxyformic acid generated in situ). Experiments were

performed to investigate reaction conversion and oxirane content of epoxidized oil.

The results will be utilized to study the influence of reaction time and temperature

on the reaction conversion, kinetics and oxirane content. The purpose is to determine

the optimal operating condition utilizing peroxyformic acid generated in situ and

also to determine if formic acid is better than acetic acid as an oxygen carrier.

4.2.1 Effects of Reaction Time and Temperature on the Conversion

The results of this study indicate the reaction conversion increases with increasing

reaction time and temperature (Figure 4-3). It means that the concentration of double

bonds decreases with increasing reaction time and temperature since double bonds

are represented by the iodine value (Petrovic et al., 2002). This finding supports

previous research with the utilization of cottonseed oil as a raw material to produce

epoxidized oil (Dinda et al., 2008). This result can be explained by the fact that

34

through the epoxidation reaction double bonds in the oil were converted to

epoxidized oil. A model that can illustrate for rate constant increases with

temperature is Arrhenius’ law (Levenspiel, 1972; Fogler, 2006):

RTEekk

/

0 . −= (4-7)

Where: 0k = frequency factor

E = activation energy

R = gas constant

T = absolute temperature (in Kelvin)

From Equation (4-7), it is clear that reaction constant ( )k is a function of reaction

temperature ( )T . If the reaction temperature goes up, the reaction constant value will

increase. Hence, it will increase the reaction rate of epoxidation and in this case a

higher final conversion resulted.

0.0

10.0

20.0

30.0

40.0

50.0

60.0

70.0

80.0

90.0

100.0

0 1 2 3 4 5 6 7

t (h)

X (

%)

40 C 50 C 60C 70 C 80 C

Figure 4-3 Effects of reaction time (t) on reaction conversion (X) for formic acid as

an oxygen carrier at different temperatures

35

4.2.2 Reaction Kinetics

Epoxidation reaction using peroxyformic acid generated in situ was performed with

a high stirring speed at 1600 rpm to avoid mass transfer resistance and to achieve an

homogenized two phase system. Research that has been conducted by Goud et al.

(2006) confirms that epoxidation of mahua oil is not controlled by mass transfer

resistance if stirring speed exceed 1500 rpm. Therefore, in this research stirring

speed at 1600 rpm was used to ensure that the epoxidation reaction was controlled

by chemical reaction. The experimental results for conversion of iodine value were

employed to determine the reaction kinetics in the epoxidation using peroxyformic

acid in terms of reaction order, rate constant and activation energy.

There are two major reactions involved in the epoxidation reaction (Petrovic et al.

2002). During the first stage, peroxyformic acid is formed from the reaction of

formic acid and hydrogen peroxide as summarized by:

HCOOH + H2O2 HCOOOH + H2O (4-8)

During the second stage, epoxidized oil is produced from the reaction between

peroxyformic acid and double bonds in the oil illustrated as:

HCOOOH + CH CH CH CH + HCOOH (4-9)

O

General form of rate equation for conversion of double bonds by peroxyformic acid

in Equation (4-10) may be written as:

[ ][ ] [ ]1 2

3

n nd DBk DB PFA

dt− = (4-10)

Where:

[ ]DB = Molar concentration of double bonds

[ ]PFA = Molar concentration of peroxyformic acid

3k = Reaction rate constant

1n = Reaction orders with respect to the double bonds concentration

36

2n = Reaction orders with respect to the peroxyformic acid concentration

If it is assumed that epoxidation is pseudo-first order with respect to the double

bonds, the rate equation for pseudo-first order can be expressed as:

[ ][ ]

d DBk DB

dt− = (4-11)

Where: [ ] 2

3

nk k PFA=

Then rate equation data for the epoxidation reaction using peroxyformic acid is

fitted with Equation (4-11). If X is expressed as the conversion of double bonds in

the oil, after integration the equation above can be defined as [ ] [ ] ( )0

1DB DB X= −

and the equation (4-11) can be integrated to give:

tkX

.1

1ln =

− (4-12)

The rate constant ( )k value for each temperature can be determined as the slope of

the plot of

− X1

1ln versus reaction time (t) and the results summarized in Table 4-

7.

Table 4-7 Rate constant value at different temperatures for epoxidation using

formic acid

Temperature (oC) k value (h

-1) R

2

40 0.172 0.9525

50 0.304 0.9423

60 0.374 0.877

70 0.425 0.862

80 0.492 0.8261

The result shows that k value increases with reaction temperatures. The present

findings are consistent with the Arrhenius equation which states that the rate

constant (k) value is dependent on temperature (T). The most interesting finding was

that the rate equation model indicated a good fit as a high significance is indicated

by high value of the correlation coefficient. Hence, it can be concluded that

epoxidation of RBO using formic acid as an oxygen carrier is pseudo-first order

37

with respect to the concentration of double bonds. Another important finding was

that at higher temperature, epoxidation reaction deviates from pseudo-first order

model since the plot of

− X1

1ln versus reaction time ( )t become less linear as

indicated by reducing correlation coefficient values as temperature increases (Table

4-7). The experimental data was taken at five different temperatures of 40, 50, 60,

70 and 80oC. Samples were taken every 1 hour reaction time and maximal 6 hour

reaction time.

The activation energy of epoxidation reaction with the use of peroxyformic acid was

calculated from k values at different temperatures by performing Arrhenius

equation:

RTEekk

/

0 . −= (4-13)

RT

Ekk −= 0lnln (4-14)

The activation energy was calculated from the slope plot of kln versus T/1 (Figure

4-4)

Figure 4-4 Determination of activation energy for epoxidation using formic acid

as an oxygen carrier

ln(k)= -2716.2(1/T) + 7.072 R 2 = 0.9065

-2

-1.8

-1.6

-1.4

-1.2

-1

-0.8

-0.6

-0.4

-0.2

0 0.0028 0.0029 0.003 0.0031 0.0032 0.0033

1/T

ln(k)

Experimental values

38

The result indicates the activation energy of epoxidation reaction using

peroxyformic acid is 22.6 kJ/mol. This value of activation energy is lower than the

results of Petrovic et al. (2002) for epoxidation of soybean oil using peroxyformic

acid (E = 35.94 kJ/mol). The lower value for the activation energy of rice bran oil is

probably related to the characteristic of the feed source. Soybean oil has a higher

concentration of double bonds in the oil with an iodine value of 125 gram iodine per

100 gram oil whereas in this research the iodine value of rice bran oil is 98.2 gram

iodine per 100 gram oil.

4.2.3 Effects of Reaction Time and Temperature on Oxirane

Content

In the synthesis of polyol, epoxidation reaction is a key aspect to obtain polyol

products with high hydroxyl value. Hence, the optimal operating condition in the

epoxidation step must be clearly defined to achieve high content of epoxy groups

since it will be used to generate raw material to produce polyol. In the epoxidation

of RBO using formic acid as an oxygen carrier as indicated in Figure 4-5, the

oxirane content of epoxidized oil increases with reaction time at lower temperatures

(40 and 50oC). From Figure 4-5, it is apparent that at higher temperatures (60, 70

and 80oC) the oxirane content increases with reaction time then achieves optimal

level before declining. These findings are also consistent with those of Dinda et al.

(2008) who found for epoxidation of cottonseed oil that at higher temperature (60oC

or higher) the relative conversion to epoxy groups increased to an optimal operating

point and then declined gradually. Maximum oxirane content of 3.26% was

achieved at 4 hours reaction time and temperature of 60oC. Hence, the results of this

study indicate that the optimal operating condition for epoxidation reaction was

achieved at a reaction time of 4 hours and a temperature of 60oC.

39

0

0.5

1

1.5

2

2.5

3

3.5

0 1 2 3 4 5 6 7

t (h)

% o

xirane

40 C

50 C

60 C

70 C

80 C

Figure 4-5 Effects of reaction time (t) on oxirane content (%) for formic acid as an

oxygen carrier at different temperatures

Given the question of which acid (acetic or formic acid) is the most suitable oxygen

carrier for epoxidation reaction, this study found that formic acid shows better

performance than acetic acid as indicated by higher content of epoxy groups with a

3.26% of oxirane content in the epoxidized oil for formic acid. In contrast to early

findings using acetic acid in Section 4.1, however only about 2.62% of maximum

value of oxirane content could be achieved. It seems possible that these results are

due to a different reactivity of acetic acid and formic acid involved in the

epoxidation reaction to produce peroxyacetic acid and peroxyformic acid. At the

first stage before the epoxidation reaction, peroxyacetic acid or peroxyformic acid

were formed from the reaction between hydrogen peroxide and acetic acid or formic

acid as follows:

CH3COOH + H2O2 CH3COOOH + H2O (peroxyacetic acid) (4-15)

HCOOH + H2O2 HCOOOH + H2O (peroxyformic acid) (4-16)

Formic acid and hydrogen peroxide in the reaction mixture will achieve equilibrium

to form peroxyformic acid at a faster rate than acetic acid (Kirk-Othmer, 1965).

Therefore a possibility to react with double bonds in the oil in the next step of the

40

H+

H+

epoxidation reaction will be higher. For this reason, peroxyformic acid was selected

as the best peroxy acid for the epoxidation step at the optimal operating condition at

a reaction time of 4 hour and a batch temperature of 60oC prior to determining the

optimal condition for the hydroxylation step in the synthesis of polyol.

Another important finding was that at higher reaction times and temperatures than

the optimal conditions a lower oxirane content will result. A possible explanation for

this observation might be that higher reaction times and temperatures favour a high

rate of oxirane ring opening thereby producing epoxidized oil with a lower oxirane

content (Purwanto et al., 2006). Therefore, side reaction products may be formed as

the oxirane ring may be decomposed due to reaction mixture contains materials that

are likely to react with the oxirane rings such as sulfuric acid, formic acid, and water

(Milchert et al., 2009). The unwanted reaction in the epoxidation reaction is

illustrated as follows:

o Hydrolysis reaction:

CH CH + H2O CH CH (4-17)

O OH OH

o Acylation reaction:

CH CH + HCOOH CH CH (4-18)

O OH OCOOH

Reaction temperatures higher than 60oC result in lower oxirane content indicated by

a reduced amount of oxirane content with reaction time (Figure 4-5). This result may

be explained by the fact that epoxidation reaction using peroxy acid in this case

peroxyformic acid is highly exothermic (Milchert et al., 2009). Hence, high

temperatures during the epoxidation reaction may cause the decomposition rate of

epoxy groups to be higher than the formation rate. As a result, lower epoxy groups

will be produced.

41

4.3 Hydroxylation of Epoxidized RBO (3rd

Study)

During the hydroxylation reaction, epoxy groups in the epoxidized oil are converted

to hydroxyl groups. Hence, the objective function for determining the optimal

condition in the hydroxylation reaction is to maximize the concentration of hydroxyl

groups as indicated by a high hydroxyl value.

4.3.1 Experimental Design and Optimization of the Hydroxylation

Reaction

A full factorial central composite design (CCD) was employed and the total number

of treatment combinations can be represented as 022 nkk ++ (Doddapaneni et al.,

2007).

Where: k2 = factorial design

k2 = star point

k = the number of independent variables

0n = the number of replications at the centre point

This third study evaluated the effect of two independent variables (reaction time and

temperature) of the hydroxylation reaction on the response variables (hydroxyl value

and viscosity). The central values of the independent variables in the hydroxylation

of epoxidized oil were a batch reaction time of 120 minutes at a temperature of

50oC. The two independent variables to be optimized were coded 1X and 2X at five

levels (-2, -1, 0, 1, 2) using the equation (4-19).

i

i

ix

xxX

∆

−= 0 (4-19)





The distribution of coded 1X and 2X at five levels is indicated in Table 4-8. At this

stage, 4 points factorial design, 4 star points and 3 replicates at the central points (all

42

factors at level 0) were performed to fit with the second order polynomial model.

Hence, 11 experiments were conducted for the hydroxylation of epoxidized oil.

Table 4-8 The range and levels of variables for hydroxylation reaction


-2 -1 0 1 2

Reaction times (min)

Temperatures (oC)

1X

2X

40 80 120 160 200

30 40 50 60 70

4.3.2 Statistical Analysis

A second-order polynomial model (Equation 4-20) was fitted to represent the

experimental data presented in Table 4-9.

2112

2

222

2

11122110 XXXXXXY ββββββ +++++= (4-20)

Where )21( −=iYi is the response ( 1Y = hydroxyl value and 2Y = viscosity); 0β is a

constant; 1β and 2β represent the linear coefficients; whilst 11β and 22β are the

quadratic coefficients; 12β is the interaction coefficients.

43

Table 4-9 CCD and response in terms of hydroxyl value and viscosity of polyol

Reaction time

(minute)

Temperature

(oC)

Hydroxyl value

(mg KOH/g oil)

Viscosity

(cP)

Exp. No.

1X 2X 1Y 2Y

1 -1 -1 126.0 34.3

2 1 -1 158.4 42.7

3 -1 1 152.6 43.8

4 1 1 107.3 61.7

5 -2 0 50.3 42.0

6 2 0 82.3 47.3

7 0 -2 119.2 29.9

8 0 2 136.2 95.3

9 0 0 159.2 43.3

10 0 0 161.5 45.1

11 0 0 159.4 44.5

The software Microsoft Excel was performed to analyze the results in the form

analysis of variance (ANOVA).

For each reaction time and corresponding temperature, the hydroxyl value ( )1Y and

viscosity ( )2Y were measured following the hydroxylation reaction. The correlation

of the responses 1Y and 2Y to coded values of variables was estimated by multiple

linear regression. The obtained regression statistics are presented in Table 4-10 and

the analysis of variance (ANOVA) is provided as Table 4-11. Analysis of regression

statistics and analysis of variance indicated a good fit and significance F < 0.05).

44

Table 4-10 Regression statistics for hydroxyl value and viscosity of polyol

Regression statistics Hydroxyl Value

( )1Y

Viscosity

( )2Y

Multiple R

R Square

Adjusted R Square

Standard Error

Observations

0.971

0.942

0.884

12.399

11

0.945

0.892

0.784

8.142

11

Table 4-11 Analyses Of Variance (ANOVA) for hydroxyl value and

viscosity of polyol

Source DF SS MS F Significance F

Hydroxyl value

(mg KOH/g oil)

Viscosity

(cP)

Regression

Residual

Total

Regression

Residual

Total

5

5

10

5

5

10

12534.6

768.6

13303.2

2737.0

331.4

3068.5

2506.9

153.7

547.4

66.3

16.31

8.26

0.0041

0.018

Table 4-12 Significance of regression coefficients for hydroxyl value of polyol


Intercept 163.187 6.360 25.657 1.68E-06a)

1X 4.252 3.579 1.188 0.28820

2X 0.775 3.579 0.217 0.83714

2

1X -23.627 2.822 -8.372 0.00040a)

2

2X -8.278 2.822 -2.933 0.03252b)

21 XX -19.419 6.199 -3.133 0.02588b)



45

Table 4-13 Significance of regression coefficients for viscosity of polyol


Intercept 42.875 4.177 10.26582 0.00015a)

1X 3.083 2.350 1.311759 0.24660

2X 13.275 2.350 5.648356 0.00242b)

2

1X 0.174 1.853 0.09381 0.92890

2

2X 4.670 1.853 2.520 0.05317

21 XX 2.380 4.071 0.585 0.58423



c Significant at 5.0% (p<0.05)

The model is a good fit of the experimental data as indicated by the high values of

the correlation coefficients (R2) for the responses. The data analysis for regression

was undertaken using Microsoft Excel whereas Matlab plotting software was

employed to visualize the results.

4.3.3 Effects of Reaction Time and Temperature on Hydroxyl

Value

The empirical relationship between hydroxyl value and the two independent

variables (reaction time and temperature) in coded units is illustrated as:

21

2

2

2

1211 419.19277.8626.23775.0252.4187.163 XXXXXXY −−−++= (4-21)

Based on Table 4-12, all the observed data was significant at p < 0.05. The results of

this study indicate that hydroxyl value is a quadratic function of reaction time and

temperature.

46

H+

+

+

.. +

Figure 4-6 Effects of reaction time (X1) and temperature (X2) on hydroxyl value

of polyol

The hydroxylation reaction using acid catalyst follows SN1 mechanism of reaction

with the formation of carbocation (Solomons, 1992). There are three main steps in

the opening ring of oxirane of epoxidized oil using acid catalyst. The detail of each

step is summarized as follows:

Step 1:

C C C C (carbocation) (4-22)

O O

H

Step 2:

C C + H O H HO C C O H (4-23)

O H

H

47

+

.. +

+ ..

+

+

+

-H+

-H+

+ -H+

C C + CH3OH HO C C OCH3 (4-24)

O H

H

CH3

C C + CH3CHCH3 OH C C O CH (4-25)

O OH H CH3

H

Step 3:

HO C C O H OH C C OH (4-26)

H

HO C C OCH3 OH C C OCH3 (4-27)

H

CH 3 CH3

OH C C O CH OH C C O CH (4-28)

H CH3 CH3

The maximal hydroxyl value was achieved at a coded reaction time 0.137 and at

coded temperature -0.113. These coded values were determined by finding

stationary points by calculation of partial derivatives of the polynomial equation for

the hydroxyl value. The real values of variables at the optimal operating condition in

the hydroxylation reaction were deduced by converting the coded values to their

original values using equation (4-19). The optimal condition for hydroxylation

reaction occurred with reaction time of 126 min at temperature of 49 oC and

produced a polyol with a maximum hydroxyl value of 161.5 mg KOH/g oil. The

result suggests that RBO is suitable as a potential feedstock for polyol production

compared to previous research by Petrovic et al. (2003) for epoxidation of corn oil

resulted a polyol with hydroxyl value of 140 mg KOH/g oil.

48

As illustrated in Figure 4-6, the hydroxyl value of hydroxilated oil (polyol) increases

with reaction time and temperature and then that value reaches an optimal level.

After that, the hydroxyl value decreases with reaction time and temperature.

Setyopratomo et al., (2006) have also reported a similar behaviour for polyol

synthesis from palm oil. A possible explanation is that after attaining the optimal

condition, the hydroxyl groups were substituted by a strong nucleophile CH3O- from

methanol excess in the mixture, as nucleophile CH3O- is stronger than nucleophile

–

OH. Below is the level of reactivity for some nucleophiles according to Solomon

(1992):

RO- > HO

- >> RCO2

- > ROH > H2O

Another possible explanation for this might be that the obtained hydroxyl groups

react with epoxy groups (Kiatsimkul et al., 2008). Explanation regarding this reason

will be discussed more in Section 4.3.4.

4.3.4 Effects of Reaction Time and Temperature on Viscosity of

Polyol

The experimental data of central composite design was fitted with a second-order

polynomial model by performing multiple linear regressions. The correlation

between viscosity of polyol products ( 2Y ) and the two independent variables

(reaction time and temperature) in coded units after applying of response surface

methodology can be correlated by the following equation:

21

2

2

2

1212 380.2670.4174.0275.13083.3875.42 XXXXXXY +++++= (4-29)

Where 2Y (viscosity of polyol in centipoise (cP)) is the response and 1X , 2X are the

coded values of independent variables (reaction time and temperature, respectively).

49

Figure 4-7 Effects of reaction time (X1) and temperature (X2) on viscosity of polyol

The result shows that the viscosity of polyol increases linearly with the rise of

temperature and this effect are positive and significant at p < 0.01 for temperature

effect only (Table 4-13). As can be seen from Figure 4-7 the viscosity of polyols

increases with reaction time and temperature and at a faster rate with temperature

than with reaction time. Through the hydroxylation reaction, viscosity of polyols

increases with reaction time and temperature until the optimal condition is attained,

as hydroxyl groups were introduced into epoxy groups to produce polyol with higher

molecular weight. In this research, results indicate that after achieving the optimal

hydroxyl value, the viscosity of polyols increases with reaction time and

temperature. A possible explanation for this might be that unexpected reaction take

place in the mixture such as polymerization or cross linking. Molecular weight or

chain length is the key factor influences the viscosity of polymer materials. The

viscosity of polymers increases with molecular weight or chain length (Billmeyer,

1984). In the mixture, hydroxyl groups may react with oxirane groups through the

reaction depicted below (Kiatsimkul et al., 2008):

50

OR’

OR’ RC CR’’

RC CR’’ + R’’’C CR’’’’ O (4-30)

OH O R’’’C CR’’’’

OH

This reaction may result in a product with higher molecular weight and will produce

polyols with higher viscosity. The viscosity of polyols in this research is in the range

between 29.9 – 95.3 cP and is considered as a reasonable viscosity. This study

confirms that the viscosity of polyol resulted from this research is close to the

typical characteristic of methyl esters polyol with viscosity of 0.1 Pa.s (100 cP)

(Petrovic, 2008). The viscosity of the polyol product in this research is lower than

another type of polyol 173 with viscosity of 5 Pa.s (5000 cP) undertaken by Petrovic

(2008). A possible explanation for this might be that as methanol was present in the

reaction, it may cause a transesterification reaction as methanol is the most reactive

alcohol (Petrovic et al., 2003). Thus, methyl ester polyol with lower viscosity

product will result. Thus, the amount or ratio of alcohol is a crucial factor in the

hydroxylation step to achieve polyol with desirable viscosity.

Figure 4-8 Sample of polyol produced

51

Figure 4-8 shows the sample of polyol product synthesized from rice bran oil

through epoxidation and hydroxylation reactions. The current conclusion is that the

economic value of rice bran oil could be increased by converting it to a polyol

product through epoxidation and hydroxylation reactions. The result suggests that

RBO is suitable as a potential feedstock for production of polyol. The starting RBO

with iodine value of 98.2 g I2/100g oil could attain maximal hydroxyl value of 161.5

mg KOH/g oil.

52

5 CONCLUSIONS

This research report has considered the possibility to use rice bran oil as a potential

feedstock for polyol production to increase its economic value. This project was

undertaken to determine the optimal operating conditions in the epoxidation and

hydroxylation steps to produce a polyol synthesized from RBO. Two initial studies

have found that generally the reaction conversion in the epoxidation reaction using

peroxyacetic acid and peroxyformic acid increases with reaction time and

temperature. A detailed study of the epoxidation step with the use of formic acid as

an oxygen carrier was performed and the kinetic parameters for a pseudo-first order

model were determined at 40, 50, 60, 70 and 80oC. The measured reaction rate for

epoxidation with peroxyformic acid were 0.172h-1

(40oC), 0.304h

-1(50

oC), 0.374h

-

1(60

oC), 0.425h

-1(70

oC) and 0.492h

-1(80

oC). The activation energy of epoxidation

with peroxyformic acid was found to equal 22.6 kJ/mol and the epoxidation reaction

was pseudo-first order with respect to the concentration of double bonds in the oil.

The oxirane content of epoxidized oil was also studied in the second study and the

result revealed that the oxirane content, represented by oxirane groups, increased

with reaction time and temperature to a maximum and then declined after achieving

the optimal point. The optimal condition for epoxidation reaction using peroxyacetic

acid was achieved at a reaction time of 4.3 hour and temperature of 63.8oC, whereas

with peroxyformic acid it was achieved at a reaction time of 4 hour and temperature

of 60oC. Another important finding is that formic acid produced a maximal oxirane

content of 3.26% was found to show improved performance compare to acetic acid

with an optimal oxirane content of only 2.62%. The final study for the hydroxylation

step has shown that the hydroxyl value of polyol is a quadratic function of reaction

time and temperature and the optimal condition was achieved at reaction time of

125.5 minute and temperature of 49oC. In terms of polyol viscosity, this value

increased with reaction time and temperature with viscosity in the range of 29.9 –

95.3 cP and temperature was found to have the most significant effect on the

viscosity of polyol. Response surface method (RSM) was employed to determine the

optimal condition in the epoxidation with peroxyacetic acid and in the hydroxylation

step. This optimization was time saving, less complex, and yet highly efficient.

53

6 RECOMMENDATIONS FOR FUTURE RESEARCH

It is recommended that further research be undertaken in the following areas:

o To investigate other factors that influence in the epoxidation reaction such as

mole ratio of hydrogen peroxide to oil, mole ratio of oxygen carrier to oil,

stirring speed, kinds and concentration of catalyst to achieve a high content

of epoxy groups in the epoxidized oil.

o To perform other methods achieving a high amount of oxirane groups in the

epoxidation step such as using metal as a catalyst.

o To investigate significant factors that have an effect on the hydroxylation

reaction to achieve a desirable viscosity of polyol such as the amount or ratio

of alcohol and water to the oil.

o To devise a process flow sheet and to perform an economic analysis of the

likely cost of an optimized process for the product of polyol from rice bran

oil.

54

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58

Appendix A – Calculation of Epoxidation Reaction

This appendix summarizes calculation of chemicals required for the epoxidation

reaction when using either acetic acid or formic acid as the oxygen carrier. Based on

the literature, a typical fatty acid composition profile for rice bran oil (Bailey, 1951)

is presented in Table A-1 below:

Table A-1 Fatty acid composition of rice bran oil

Fatty acids Composition (wt %) Molecular Weight (MW)

Myristic acid (C14H28O2)

Palmitic acid (C16H32O2)

Stearic acid (C18H36O2)

Arachidic acid (C20H40O2)

Lignoceric acid (C24H48O2)

Oleic acid (C18H34O2)

Linoleic acid (C18H32O2)

0.5

11.7

1.7

0.5

0.4

39.2

35.1

228.37

256.42

284.48

312.53

368.64

282.46

280.45

Total mole of rice bran oil (RBO) is expressed as concentration of double bonds

(DB) in the oil → ( )tn :

Volume of RBO )(V 200= mL

Density of RBO 9166.0)( =ρ mL

g(Bailey, 1951)

Mass of RBO ( )( ) 32.183200.9166.0. === Vm ρ g

• n Myristic acid ( )( )

004014.037.228

32.183005.0== mol

• n Palmitic acid ( )( )

0836.042.256

32.183117.0== mol

• n Stearic acid ( )( )

01095.048.284

32.183017.0== mol

• n Arachidic acid ( )( )

00293.053.312

32.183005.0== mol

• n Lignoceric acid ( )( )

00199.064.368

32.183004.0== mol

59

• n Oleic acid ( )( )

2544.046.282

32.183392.0== mol

• n Linoleic acid ( )( )

2294.045.280

32.182351.0== mol

2294.02544.000199.000293.001095.00836.0004014.0 ++++++=tn

587284.0=tn mol

Total mole of RBO = 0.587 mol.

Acetic acid or formic acid:

Mole ratio of acetic acid or formic acid to DB = 0.5 : 1

o Glacial acetic acid (99.7 wt%), MW = 60.05, density ( ) 05.1=ρ mL

g

Mole of acetic acid ( ) ( )( ) 294.0587.05.05.0 === tn mol

Mass of acetic acid ( )( ) 63.1705.60294.0 == gram

Mass of glacial acetic acid ( ) 68.1763.177.99

100=

= gram

Volume of glacial acetic acid required 8.1684.1605.1

68.17≈== mL.

o Formic acid (90 wt%), MW = 46.03, density ( ) 20.1=ρ mL

g

Mole of formic acid ( ) ( )( ) 294.0587.05.05.0 === tn mol

Mass of formic acid ( )( ) 52.1303.46294.0 == gram

Mass of formic acid solution ( ) 02.1552.1390

100=

= gram

Volume of glacial acetic acid needed 5.1252.1220.1

02.15≈== mL.

Hydrogen peroxide:

Mole ratio of hydrogen peroxide to DB = 1.5 : 1

Hydrogen peroxide (30 wt%), MW = 34.01, density 10.1)( =ρ mL

g

Mole of hydrogen peroxide ( )( ) 881.0587.05.1 == mol

Mass of hydrogen peroxide ( )( ) 96.2901.34881.0 == gram

60

Mass of hydrogen peroxide solution ( ) 88.9996.2930

100=

= gram

Volume of hydrogen peroxide solution 8.90797.9010.1

88.99≈== mL.

Sulfuric acid catalyst:

Mass of sulfuric acid in the mixture is 3% of total mass of hydrogen peroxide and

acetic acid or formic acid.

Sulfuric acid (98 wt %), MW = 98.08, density ( ) 84.1=ρ mL

g

o Epoxidation of RBO using acetic acid as an oxygen carrier:

Mass of sulfuric acid ( )COOHCHOH 322100

3+

=

Mass of sulfuric acid ( ) 43.163.1796.29100

3=+

= gram

Mass of sulfuric acid solution ( ) 46.143.198

100=

= gram

Volume of sulfuric acid solution 8.0792.084.1

46.1≈== mL.

o Epoxidation of RBO using formic acid as an oxygen carrier:

Mass of sulfuric acid ( )HCOOHOHx +

= 22

100

3

Mass of sulfuric acid ( ) 30.152.1396.29100

3=+

= x gram

Mass of sulfuric acid solution 33.130.198

100== x gram

Volume of sulfuric acid solution 7.072.084.1

33.1≈== mL.

61

Appendix B – Calculation of Hydroxylation Reaction

This appendix summarizes calculation of chemicals required in the hydroxylation

reaction. The mixture of alcohol (methanol and isopropanol) and water were used to

introduce hydroxyl groups into epoxy groups. The detail of calculation is illustrated

as follows:

Total moles of epoxy groups in 150 mL of epoxidized oil ( )epoxyn :

( ) 44.0587.0200

150=

=epoxyn mol

( ) 49.13732.183200

150=

=epoxym gram

o Methanol (99 wt%), MW = 32.04, density ( )mL

g79.0=ρ

Mole ratio of epoxy groups to methanol (CH3OH) = 1 : 4

Mole of methanol ( )( ) 76.144.04 == mol

Mass of methanol ( )( ) 45.5604.3276.1 == gram

Mass of methanol solution ( ) 02.5745.5699

100=

= gram

Volume of methanol solution 2.72182.7279.0

02.57≈== mL.

o Isopropanol (99.5 wt%), MW = 60.10, density ( ) 78.0=ρ mL

g

Mole ratio of epoxy groups to isopropanol = 1 : 4

Mole of isopropanol 76.144.04 == x mol

Mass of isopropanol ( )( ) 90.1051.6076.1 == gram

Mass of isopropanol solution ( ) 43.10690.1055.99

100=

= gram

Volume of isopropanol solution 4.13645.13678.0

43.106≈== mL.

o Water, MW = 18.02, density ( ) 1=ρ mL

g

Mole ratio of epoxy groups to water = 1 : 2

Mole of water ( )( ) 88.044.02 == mol

Mass of water ( )( ) 88.1502.1888.0 == gram

62

Volume of water 9.15876.151

88.15≈== mL.

o Sulfuric acid (98 wt%), MW = 98.08, density ( ) 84.1=ρ mL

g

Mass of catalyst = 1% total mass of methanol, isopropanol and water

Mass of sulfuric acid ( )waterlisopropanomethanol mmm ++

=

100

1

Mass of sulfuric acid ( ) 78.188.1590.10545.56100

1=++

= gram

Mass of sulfuric acid solution ( ) 82.178.198

100=

= gram

Volume of sulfuric acid solution 1988.084.1

82.1≈== mL.

63

Appendix C – Epoxidation Using Acetic Acid as an Oxygen

Carrier (1st Study)

The first study of this research deals with determination of the optimal operating

condition in the epoxidation of RBO using acetic acid as an oxygen carrier. Thus,

this appendix consists of two sections. The first section summarizes the calculation

of iodine value and the last one illustrates the calculation of oxirane content as

indicator the amount of oxirane groups.

C.1 Experimental Design

Response surface methodlogy (RSM) was performed to determine the optimal

operating condition in the epoxidation reaction by applying a second-order

polynomial model among two independent variables: reaction time and temperature.

A full factorial central composite design (CCD) was performed with a total number

of treatment combination of 022 nkk ++ , where

- k2 = factorial design ( )422 =

- k2 = star point ( )42.2 =

- 0n = replication at the central points ( )3

- k = number of independent variables ( )2

Central values for epoxidation reaction for two independent variables:

- Reaction time : 4 h

- Temperature : 60oC

The two variables were coded 1X and 2X at five levels (-2, -1, 0, 1 and 2) by

utilizing the equation:

i

i

ix

xxX

∆

−= 0 (C-1)

Where: iX = coded value of independent variables

ix = real value of independent variables

0x = real value of independent variables at centre point

ix∆ = step change value (interval)

64

Hence, there were eleven experiments in the epoxidation reaction using acetic acid

as an oxygen carrier were conducted and the results will be fitted with second-order

polynomial model given. The range and level of variables investigated are listed in

Table C-1 whereas the experimental design is illustrated in Table C-2.

Table C-1 Range and levels of variables


-2 -1 0 1 2

Reaction time (hour)

Temperature (oC)

1X

2X

2 3 4 5 6

40 50 60 70 80

Table C-2 Experimental design of epoxidation using acetic acid as an oxygen

carrier

Experiments 1X 2X Experimental

design

Conversion

(%)

Oxirane

content (%)

1

2

3

4

5

6

7

8

9

10

11

-1

1

-1

1

-2

2

0

0

0

0

0

-1

-1

1

1

0

0

-2

2

0

0

0

22 full factorial

design

(4 experiments)

2x2 star points

(4 experiments)

Central points

(3 experiments)

65

C.2 Determination of Iodine Value and Conversion

In order to determine the conversion of iodine value, the iodine value of Rice Bran

Oil (RBO) is calculated using the following equation:

Iodine value

( )

C

xNxAB 69.12−

= (C-2)


B = Volume of Na2S2O3 solution required for titration of the blank (mL).

C = weight of sample used (g)

N = normality of the Na2S2O3 (0.1 N)

o Initial iodine value of Rice Bran Oil 0( )IV expressed as iodine value at t = 0:

1.0322

=OSNaN N

17.0=C g

9.201 =B mL , 7.202 =B mL → ( ) 8.202/7.209.20 =+=avB mL

7.71 =A mL , 6.72 =A mL → ( ) 65.72/6.77.7 =+=avA mL

( )( )( )2.98

17.0

69.121.065.78.200 =

−=IV gram I2/100 gram oil.

o Conversion of iodine value (% )X :

( )%100%0

0

−=

IV

IVIVX (C-3)

Where: 0IV = initial iodine value

IV = iodine value at certain condition

o Reaction time (t) = 4 h and T = 60oC

2.0=C g, 7.151 =A mL and 9.152 =A mL

8.152

9.157.15=

+=avA mL

Iodine Value: ( )( )( )

7.312.0

69.121.08.158.20=

−=IV gram I2/100 gram oil

%7.67%1002.98

7.312.98% =

−= xX

66

The iodine value and conversion at other fixed reaction times and temperatures is

summarized in Table C-3.

Table C-3 Experimental results of iodine value & conversion

No t (h) T (oC) C (g) A1 (mL) A2 (mL) Aav (mL) IV % X

1 4 60 0.2 15.7 15.9 15.8 31.7 67.7

2 4 40 0.21 8.5 8.3 8.4 74.9 23.7

3 3 50 0.21 12.8 12.7 12.75 48.6 50.5

4 5 50 0.19 16.1 16 16.05 31.7 67.7

5 2 60 0.22 11 11.1 11.05 56.2 42.7

6 4 60 0.18 16 15.9 15.95 34.2 65.2

7 6 60 0.16 18.2 18.1 18.15 21.0 78.6

8 3 70 0.18 16.3 16.3 16.3 31.7 67.7

9 5 70 0.17 18.4 18.3 18.35 18.3 81.4

10 4 80 0.21 18.9 18.8 18.85 11.8 88.0

11 4 60 0.18 16 16 16 33.8 65.5

C.3 Oxirane Content

The amount of oxirane groups indicated by the percentage of oxirane oxygen

content that can be calculated using the equation below:

% oxygen content

( )

1000

10016

xW

xxNxVV sb −

= (C-4)

Where: b

V = volume of NaOH used for blank (mL)

s

V = volume of NaOH used for sample (mL)

N = normality of NaOH = 0.1 N

W = weight of the sample (g)

o Volume of NaOH used for blank:

1bV = 19.3 mL, 2b

V = 19.1 mL → ( ) 2.192/1.193.19 =+=−avbV mL

o Reaction time (t) = 4 h and T = 60oC

19.0=W g, 161 =sV mL and 2.162 =sV mL

1.162

2.1616=

+=−avsV mL

67

( )( )( )( )

( )( )%61.2

100019.0

100161.01.162.19% =

−=oxirane

The amount of oxirane oxygen content at other fixed reaction times and

temperatures is summarized in Table C-4.

Table C-4 Experimental results of oxirane oxygen content

No t (h) T (oC) W (g) Vs1 (mL) Vs2 (mL) Vs av (mL) % oxirane

1 4 60 0.19 16 16.2 16.1 2.61

2 4 40 0.15 17.7 17.6 17.65 1.65

3 3 50 0.18 17.3 17.3 17.3 1.69

4 5 50 0.17 16.8 17 16.9 2.16

5 2 60 0.2 16.9 17.1 17 1.76

6 4 60 0.22 15.6 15.6 15.6 2.62

7 6 60 0.2 16.2 16.2 16.2 2.40

8 3 70 0.19 16.3 16.2 16.25 2.48

9 5 70 0.19 16.4 16.5 16.45 2.32

10 4 80 0.24 15.8 16 15.9 2.20

11 4 60 0.18 16.3 16.3 16.3 2.58

C.4 Determination of the Optimal Condition

The empirical relationship between oxirane content and the two independent

variables (reaction time and temperature) in coded units is represented as:

21

2

2

2

1212 161.0165.0127.0170.0132.0543.2 XXXXXXY −−−++= (C-5)

The optimal condition can be obtained by calculating the partial derivatives of the

equation and then setting them equal to zero to determine the stationary points.

0161.0254.0132.0 21

1

2 =−−=∂

∂XX

X

Y (C-6)

132.0161.0254.0 21 =+ XX (C-7)

0161.033.0170.0 12

2

2 =−−=∂

∂XX

X

Y (C-8)

170.033.0161.0 21 =+ XX (C-9)

Substitution Equation (C-3) to Equation (C-5):

28.01 =X and 38.02 =X

The real values of reaction time and temperature:

68

i

i

ix

xxX

∆

−= 0 → ( )iii xXxx ∆+= .0

( ) 3.428.4128.041 ≈=+= xx h (reaction time)

( ) 8.631038.0602 =+= xxoC (temperature)

69

Appendix D – Epoxidation Using Formic Acid as an

Oxygen Carrier (2nd

Study)

The second study performed in this study deals with determination of the optimal

operating condition in the epoxidation of RBO using formic acid as an oxygen

carrier rather than acetic acid and then followed by determination of reaction kinetic

parameters. Thus, this appendix consists of three sections. The first section deals

with the calculation of conversion of iodine value then followed determination of

reaction kinetic parameters whereas the last section illustrates the calculation of

oxirane content as indicator the amount of oxirane groups.

D.1 Determination of Iodine Value and Conversion

In order to determine conversion of iodine value, the iodine value of Rice Bran Oil

(RBO) is calculated using the following equation:

Iodine value

( )

C

xNxAB 69.12−

= (D-1)


B = Volume of Na2S2O3 solution required for titration of the blank (mL).

C = weight of sample used (g)

N = normality of the Na2S2O3 (0.1 N)

o Initial iodine value of Rice Bran Oil 0( )IV expressed as iodine value at t = 0

hours:

1.0322

=OSNaN N

17.0=C g

9.201 =B mL , 7.202 =B mL → ( ) 8.202/7.209.20 =+=avB mL

7.71 =A mL , 6.72 =A mL → ( ) 65.72/6.77.7 =+=avA mL

( )( )( )2.98

17.0

69.121.065.78.200 =

−=IV gram I2/100 gram oil.

70

o Conversion of iodine value (% )X :

%100%0

0 xIV

IVIVX

−= (D-2)

Where: 0IV = initial iodine value

IV = iodine value at certain condition

o Calculation at T = 40oC:

- Reaction time (t) = 1 hour

24.0=C g, 3.71 =A mL and 4.72 =A mL

35.72

4.73.7=

+=avA mL

Iodine Value:( )( )( )

1.7124.0

69.121.035.78.20=

−=IV g I2/100 g oil

( ) %6.27%1002.98

1.712.98% =

−=X


21.0=C g, 9.91 =A mL and 9.92 =A mL

9.92

9.99.9=

+=avA mL


9.6521.0

69.121.09.98.20=


( ) %9.32%1002.98

9.652.98% =

−=X


24.0=C g, 101 =A mL and 9.92 =A mL

95.92

9.910=

+=avA mL


4.5724.0

69.121.095.98.20=


( ) %6.41%1002.98

4.572.98% =

−=X


22.0=C g, 6.121 =A mL and 5.122 =A mL

71

55.122

5.126.12=

+=avA mL

Iodine Value: ( )20.8 12.55 (0.1)(12.69)

47.60.22

IV−

= = g I2/100 g oil

98.2 47.6% 100% 51.5%

98.2X x

−= =


21.0=C g, 9.131 =A mL and 9.132 =A mL

9.132

9.139.13=

+=avA mL

Iodine Value: ( )20.8 13.9 (0.1)(12.69)

41.70.21

IV−

= = g I2/100 g oil

98.2 41.7% 100% 57.5%

98.2X x

−= =


20.0=C g, 8.141 =A mL and 0.152 =A mL

9.142

0.158.14=

+=avA mL

Iodine Value: ( )20.8 14.9 (0.1)(12.69)

37.40.20

IV−

= = g I2/100 g oil

98.2 37.4% 100% 61.9%

98.2X x

−= =

The conversion of iodine value at 40oC and other reaction temperatures (50, 60, 70

and 80oC) is summarized in Table D-1 to D-5.

Table D-1 Experimental results of Iodine Value (IV) and Conversion (%X) at 40oC

t (h) C (g) A1 (mL) A2 (mL) Aav (mL) IV %X

0 0.17 7.7 7.6 7.65 98.2 0.0

1 0.24 7.3 7.4 7.35 71.1 27.6

2 0.21 9.9 9.9 9.9 65.9 32.9

3 0.24 10 9.9 9.95 57.4 41.6

4 0.22 12.6 12.5 12.55 47.6 51.5

5 0.21 13.9 13.9 13.9 41.7 57.5

6 0.2 14.8 15 14.9 37.4 61.9

72



0 0.17 7.7 7.6 7.65 98.2 0.0

1 0.28 8.1 8.1 8.1 57.6 41.4

2 0.21 13.6 13.4 13.5 44.1 55.1

3 0.2 14.8 14.8 14.8 38.1 61.2

4 0.23 15.4 15.4 15.4 29.8 69.6

5 0.23 17.1 17.2 17.15 20.1 79.5

6 0.24 17.3 17.3 17.3 18.5 81.1



0 0.17 7.7 7.6 7.65 98.2 0.0

1 0.22 12.2 12.1 12.15 49.9 49.2

2 0.18 15.7 15.8 15.75 35.6 63.7

3 0.22 16.9 16.9 16.9 22.5 77.1

4 0.2 17.4 17.5 17.45 21.3 78.3

5 0.24 17.3 17.5 17.4 18.0 81.7

6 0.21 18.7 18.7 18.7 12.7 87.1



0 0.17 7.7 7.6 7.65 98.2 0.0

1 0.23 13 13 13 43.0 56.2

2 0.19 16.6 16.7 16.65 27.7 71.8

3 0.25 16.7 16.6 16.65 21.1 78.5

4 0.21 18 18 18 16.9 82.8

5 0.24 18.3 18.3 18.3 13.2 86.5

6 0.22 19 19.1 19.05 10.1 89.7



0 0.17 7.7 7.6 7.65 98.2 0.0

1 0.26 13.4 13.6 13.5 35.6 63.7

2 0.21 16.8 16.9 16.85 23.9 75.7

3 0.22 17.8 17.7 17.75 17.6 82.1

4 0.22 19 19 19 10.4 89.4

5 0.24 19 19.2 19.1 9.0 90.8

6 0.23 19.3 19.3 19.3 8.3 91.6

73

k1

k2

k3

D.2 Reaction Kinetics

The epoxidation reaction of RBO using formic acid as an oxygen carrier consists of

two steps that can be illustrated as follows (Petrovic et al. 2002):

Step 1: Formation of peroxyformic acid (reaction 1)

FA + H2O2 PFA + H2O (D-3)

Step 2: Epoxidation reaction (reaction 2)

DB + PFA EO + FA (D-4)

Where : FA = Formic acid

PFA = Peroxyformic acid

DB = Double bonds

EO = Epoxidized oil

k1, k2 & k3 = Reaction rate constant

General form of rate equation for conversion of double bonds by peroxyformic acid

(reaction 2) may be written as:

[ ][ ] [ ]1 2

3

n nd DBk DB PFA

dt− = (D-5)

Where:

[ ]DB = Molar concentration of double bonds

[ ]PFA = Molar concentration of peroxoformic acid

k3 = Reaction rate constant

1n = Reaction orders with respect to the double bonds concentration

2n = Reaction orders with respect to the peroxoformic acid concentration

If it is assumed that epoxidation is pseudofirst order with respect to the double

bonds, the rate equation for pseudofirst order can be expressed as:

[ ]

[ ]d DB

k DBdt

− = (D-6)

Where: [ ] 2

3

nk k PFA=

74

Then rate equation data for the epoxidation reaction using peroxoformic acid is

fitted with the equation above. If X is expressed as the conversion of double bonds

in the oil, after integration the equation above and defines [ ] [ ] ( )0

1DB DB X= − the

equation above can be simplified as:

[ ][ ]

d DBk DB

dt− =

[ ] ( )( )[ ] ( )0

0

11

d DB Xk DB X

dt

−− = −

[ ] [ ] ( )0 0

1dX

DB k DB Xdt

= −

( )1dX

k Xdt

= −

.1

dXk dt

X=

− (D-7)

Integration at 0 0t X= → = and t t X X= → = :

0 0

.1

t tdX

k dtX

=−∫ ∫

1ln .

1k t

X=

− (D-8)

The rate constant (k) value for each temperature can be determined as the slope of

plot of 1

ln1 X−

versus reaction time (t).

Determination of reaction rate constant (k):

The calculation to determine rate constant value was provided by Table D-6 to Table

D-10.

75

Table D-6 Determination of k value at 40oC

t (h) X 1/(1-X) ln 1/1-X

0 0.000 1.00 0.000

1 0.276 1.38 0.322

2 0.329 1.49 0.399

3 0.416 1.71 0.537

4 0.515 2.06 0.724

5 0.575 2.35 0.856

6 0.619 2.62 0.964

ln1/(1-X) = 0.1724t

0.00

0.20

0.40

0.60

0.80

1.00

1.20

0 1 2 3 4 5 6

t (h)

ln1/(

1-X

)

Figure D-1 Plot reaction time vs ln1/(1-X) at T = 40oC

According to Figure D-1, the reaction rate constant at T = 40oC:

172.0== slopek h-1


t (h) X 1/(1-X) ln 1/1-X

0 0.000 1.00 0.000

1 0.414 1.71 0.534

2 0.551 2.23 0.800

3 0.612 2.58 0.947

4 0.696 3.29 1.192

5 0.795 4.87 1.584

6 0.811 5.30 1.668

76

ln1/(1-X) = 0.3041t

0.00

0.20

0.40

0.60

0.80

1.00

1.20

1.40

1.60

1.80

2.00

0 1 2 3 4 5 6

t (h)

ln1/(

1-X

)



304.0== slopek h-1


t (h) X 1/(1-X) ln 1/1-X

0 0.000 1.00 0.000

1 0.492 1.97 0.677

2 0.637 2.76 1.014

3 0.771 4.36 1.473

4 0.783 4.62 1.530

5 0.817 5.46 1.697

6 0.871 7.74 2.046

77

ln1/(1-X) = 0.3737t

0.00

0.50

1.00

1.50

2.00

2.50

0 1 2 3 4 5 6

t (h)

ln1/(

1-X

)



374.0== slopek h-1


t (h) X 1/(1-X) ln 1/1-X

0 0.000 1.00 0.000

1 0.562 2.28 0.825

2 0.718 3.54 1.265

3 0.785 4.66 1.539

4 0.828 5.80 1.758

5 0.865 7.43 2.005

6 0.897 9.72 2.275

78

ln1/(1-X) = 0.425t

0.00

0.50

1.00

1.50

2.00

2.50

3.00

0 1 2 3 4 5 6

t (h)

ln1/(

1-X

)



1425.0 −== hslopek


t (h) X 1/(1-X) ln 1/1-X

0 0.000 1.00 0.000

1 0.637 2.76 1.013

2 0.757 4.11 1.414

3 0.821 5.58 1.719

4 0.894 9.45 2.246

5 0.908 10.92 2.391

6 0.916 11.86 2.473

79

ln1/(1-X) = 0.492t

0.00

0.50

1.00

1.50

2.00

2.50

3.00

3.50

0 1 2 3 4 5 6

t (h)

ln1/(

1-X

)



492.0== slopek h-1

Determination of activation energy:

The activation energy for epoxidation reaction with the use of peroxyformic acid is

determined from the rate constants at different temperature using Arrhenius

equation:

RTEekk

/

0 . −= (D-9)

RT

Ekk −= 0lnln (D-10)

Therefore the activation energy can be calculated from the slope plot of kln vs

T/1 . The calculation of activation energy is summarized in Table D-11.

Table D-11 Calculation of activation energy

T (K) 1/T k ln(k)

313 0.003195 0.1724 -1.75794

323 0.003096 0.3041 -1.1904

333 0.003003 0.3737 -0.9843

343 0.002915 0.425 -0.85567

353 0.002833 0.492 -0.70928

80

ln(k)= -2716.2(1/T) + 7.072

R2 = 0.9065

-2

-1.8

-1.6

-1.4

-1.2

-1

-0.8

-0.6

-0.4

-0.2

0

0.0028 0.0029 0.003 0.0031 0.0032 0.0033

1/T

ln(k

)

Series1 Linear (Series1)

Figure D-6 Plot ln(k) vs 1/T

From Figure D-7, activation energy is determined:

KR

Eslope 2.2716−=−=

KmolJKxRE

.314.82.27162.2716 ==

molkJ

molJE 6.2249.22582 ==

D.3 Oxirane Oxygen Content

The number of oxirane groups indicated by the percentage of oxirane oxygen

content that can be calculated using the equation below:

% oxygen content

( ) 16 100

1000

b sV V x N x x

W x

−

= (D-11)

Where: b

V = volume of NaOH used for blank (mL)

s

V = volume of NaOH used for sample (mL)

N = normality of NaOH = 0.1 N

W = weight of the sample (g)

81

o Volume of NaOH used for blank:

1bV = 19.3 mL, 2b

V = 19.1 mL → ( ) 2.192/1.193.19 =+=−avbV mL

o Calculation at T = 40oC


23.0=W g, 1.181 =sV mL and 2.182 =sV mL

15.182

2.181.18=

+=−avsV mL

( )19.2 18.15 (0.1)(16)(100)

% 0.73%0.23

oxirane−

= =


19.0=W g, 9.171 =sV mL and 9.172 =sV mL

9.172

9.179.17=

+=−avsV mL

( )19.2 17.9 (0.1)(16)(100)% 1.09%

0.19oxirane

−= =


22.0=W g, 171 =sV mL and 9.162 =sV mL

95.162

9.1617=

+=−avsV mL

( )19.2 16.95 (0.1)(16)(100)% 1.64%

0.22oxirane

−= =


23.0=W g, 5.161 =sV mL and 5.162 =sV mL

5.162

5.165.16=

+=−avsV mL

( )19.2 16.5 (0.1)(16)(100)% 1.88%

0.23oxirane

−= =


26.0=W g, 2.161 =sV mL and 162 =sV mL

1.162

162.16=

+=−avsV mL

( )19.2 16.1 (0.1)(16)(100)% 1.91%

0.26oxirane

−= =

82


21.0=W g, 3.161 =sV mL and 4.162 =sV mL

35.162

4.163.16=

+=−avsV mL

( )19.2 16.35 (0.1)(16)(100)% 2.17%

0.21oxirane

−= =

The amount of oxirane oxygen content at 40oC and other reaction temperatures (50,

60, 70 and 80oC) summarized in Table D-12 to Table16.

Table D-12 Experimental results of oxirane oxygen content at T = 40oC

t (h) W (g) Vs1 (mL) Vs2 (mL) Vs-av (mL) % oxirane

1 0.23 18.10 18.20 18.15 0.73

2 0.19 17.90 17.90 17.90 1.09

3 0.22 17.00 16.90 16.95 1.64

4 0.23 16.50 16.50 16.50 1.88

5 0.26 16.20 16.00 16.10 1.91

6 0.21 16.30 16.40 16.35 2.17



1 0.22 18.00 17.90 17.95 0.91

2 0.29 16.20 16.30 16.25 1.63

3 0.24 16.30 16.10 16.20 2.00

4 0.25 15.50 15.50 15.50 2.37

5 0.25 15.40 15.30 15.35 2.46

6 0.22 15.60 15.50 15.55 2.65



1 0.25 17.80 17.70 17.75 0.93

2 0.25 16.20 16.20 16.20 1.92

3 0.26 15.30 15.40 15.35 2.37

4 0.26 13.90 13.90 13.90 3.26

5 0.22 14.90 14.80 14.85 3.16

6 0.19 15.60 15.50 15.55 3.07

83



1 0.25 17.40 17.40 17.40 1.15

2 0.23 16.10 16.20 16.15 2.12

3 0.25 15.40 15.50 15.45 2.40

4 0.19 16.50 16.40 16.45 2.32

5 0.25 15.70 15.60 15.65 2.27

6 0.22 16.20 16.20 16.20 2.18



1 0.25 17.20 17.20 17.20 1.28

2 0.23 15.80 15.80 15.80 2.37

3 0.19 16.50 16.50 16.50 2.27

4 0.22 16.20 16.30 16.25 2.15

5 0.24 16.10 16.20 16.15 2.03

6 0.27 15.90 15.70 15.80 2.01

84

Appendix E – Hydroxylation of Epoxidized Oil

E.1 Experimental Design

Response surface methodlogy (RSM) was utilized to determine the optimal

operating condition in the hydroxylation reaction by applying a second-order

polynomial model with two independent variables: reaction time and batch

temperature. A full factorial central composite design (CCD) was performed with a

total number of treatment combination of 022 nkk ++ , where

- k2 = factorial design ( )422 =

- k2 = star point ( )42.2 =

- 0n = replication at the central points ( )3

- k = number of independent variables ( )2

Central values for hydroxylation reaction for two independent wariables:

- Reaction time : 120 minutes

- Temperature : 50oC

Those central values were chosen based on the optimal condition for hydroxylation

of epoxidized palm oil by Setyopratomo et al. (2006) attained at a reaction time 120

minutes and a temperature of 50oC.

The two variables were coded 1X and 2X at five levels (-2, -1, 0, 1 and 2) by

utilizing the equation:

i

i

ix

xxX

∆

−= 0 (E-1)

Where: iX = coded value of independent variables

ix = real value of independent variables

0x = real value of independent variables at centre point

ix∆ = step change value (interval)

Hence, there were eleven experiments conducted in the hydroxylation and the results

were fitted with second-order polynomial model. The range and level of variables

investigated are listed in Table E-1 and the experimental design is illustrated in

Table E-2.

85

Table E-1 Range and levels of hydroxylation reaction


-2 -1 0 1 2

Reaction time (min)

Temperature (oC)

1X

2X

40 80 120 160 200

30 40 50 60 70

Table E-2 Experimental design of hydroxylation reaction

Experiments 1X 2X Experimental

Design

Hydroxyl

value

Viscosity

1

2

3

4

5

6

7

8

9

10

11

-1

1

-1

1

-2

2

0

0

0

0

0

-1

-1

1

1

0

0

-2

2

0

0

0

22 full factorial

design

(4 experiments)

2x2 star points

(4 experiments)

Central points

(3 experiments)

E.2 Determination of Hydroxyl Value

In order to determine the hydroxyl value of polyol products, the saponification value

of polyol before and after acetylation process must be determined.

Saponification value before acetylation (SB):

Saponification value of polyol is determined using the following equation:

( ) 28.05A B x

SBG

−

= (E-2)

Where: A = volume of HCl 0.5N for blank titration (mL)

B = volume of HCl 0.5N for sample titration (mL)

G = weight of sample (g)

86

o Volume of HCl for blank titration:

1.171 =A mL, 1.172 =A mL → 1.172

1.171.17=

+=avA mL

o Reaction time (t) = 80 minute and temperature (T) = 40oC:

59.1=G g, 8.81 =B mL, 92 =B mL

9.82

98.8=

+=avB mL

( ) ( )(28.05) 17.1 8.9 (28.05)144.7

1.59

av avA B

SBG

− −= = =

The calculation of saponification value before acetylation process for other fixed

reaction and temperature is provided in Table E-3.

Table E-3 Saponification value prior to acetylation

t (min) T (oC) G (g) B1 B2 Bav SB

80 40 1.59 8.80 9.00 8.900 144.7

160 40 0.90 12.4 12.3 12.35 148.0

80 60 1.52 9.00 9.00 9.000 149.5

160 60 1.70 8.20 8.30 8.250 146.0

40 50 1.61 8.90 8.80 8.850 143.7

200 50 1.72 8.30 8.20 8.250 144.3

120 30 1.74 8.10 8.20 8.150 144.3

120 70 1.65 8.40 8.60 8.500 146.2

120 50 1.54 8.80 8.80 8.800 151.2

120 50 1.23 10.4 10.6 10.50 150.5

120 50 1.46 9.20 9.20 9.200 151.8

Saponification value after acetylation (SA):

Saponification value of acetylated polyol is determined using the following

equation:

( ) 28.05A B x

SAG

−

= (E-3)

Where: A = volume of HCl 0.5N for blank titration (mL)

B = volume of HCl 0.5N for sample titration (mL)

G = weight of sample (g)

o Volume of HCl for blank titration:

1.171 =A mL, 1.172 =A mL → 1.172

1.171.17=

+=avA mL

87

o Reaction time (t) = 80 minute and temperature (T) = 40oC:

76.0=G g, 4.101 =B mL, 4.102 =B mL

4.102

4.104.10=

+=avB mL

( ) ( )(28.05) 17.1 10.4 (28.05)247.3

0.76

av avA B

SAG

− −= = =

The calculation of saponification value after acetylation process for other fixed

reaction and temperature is provided in Table E-4.

Table E-4 Saponification value after acetylation

t (min) T (oC) G (g) B1 B2 Bav SA

80 40 0.76 10.4 10.4 10.40 247.3

160 40 0.85 8.90 8.70 8.800 273.9

80 60 0.74 9.90 10.0 9.950 271.0

160 60 0.67 11.5 11.5 11.50 234.5

40 50 0.54 13.5 13.5 13.50 187.0

200 50 0.46 13.5 13.7 13.60 213.4

120 30 0.69 11.2 11.1 11.15 241.9

120 70 0.75 10.2 10.3 10.25 256.2

120 50 0.86 8.60 8.60 8.600 277.2

120 50 0.63 10.8 10.9 10.85 278.3

120 50 0.55 11.7 11.6 11.65 278.0

Hydroxyl Value of Polyol Products:

The hydroxyl value of polyol products is calculated using the following equation

(Ketaren, 2005):

1 0.00075 )

SA SBHV

x SA

−=

−

(E-4)

Where: HV = Hydroxyl Value

SA = Saponification value after acetylation

SB = Saponification value before acetylation

o Reaction time (t) = 80 minute and temperature (T) = 40oC

7.144=SB and 3.247=SA

( )99.125

3.24700075.01

7.1443.247=

−

−=

xHV

88

The calculation of hydroxyl value for other fixed reaction times and temperatures is

presented in the Table E-5.

Table E-5 Hydroxyl value of polyol

t (min) T (oC) SB SA HV

80 40 144.66 247.28 125.99

160 40 148.04 273.90 158.40

80 60 149.48 271.02 152.56

160 60 146.03 234.45 107.29

40 50 143.73 187.00 50.320

200 50 144.33 213.42 82.260

120 30 144.28 241.88 119.23

120 70 146.20 256.19 136.15

120 50 151.18 277.24 159.15

120 50 150.51 278.27 161.46

120 50 151.78 277.95 159.40

E.3 Determination of the Optimal Condition

The empirical relationship between hydroxyl values and the two independent

variables (reaction time and temperature) in coded units is represented as:

21

2

2

2

1211 419.19278.8626.23775.0252.4187.163 XXXXXXY −−−++= (E-5)

The optimal condition can be obtained by determining the partial derivatives of the

above, setting equal to zero , and solving simultaneously.

0419.19252.47252.4 21

1

1 =−−=∂

∂XX

X

Y (E-6)

252.4419.19252.47 21 =+ XX (E-7)

0419.19556.16775.0 12

2

1 =−−=∂

∂XX

X

Y (E-8)

775.0556.16419.19 21 =+ XX (E-9)

Substitution Equation (1) to Equation (2):

137.01 =X and 114.02 −=X

The real values of reaction time and temperature:

i

i

ix

xxX

∆

−= 0 → ( )iii xXxx ∆+= .0

89

( ) 5.12548.12540137.01201 ≈=+= xx min (reaction time)

( )( ) Cxx o4986.4810114.0502 ≈=−+= (temperature)

E.4 Determination of the Viscosity of the Polyol Products

In order to determine the viscosity of polyol products, Brookfield viscometer VT

550 was used and data on the shear stress ( )τ and correspond shear rate

•

γ was

collected at different speeds. The viscosity of polyol is calculated using the

following equation:

•=

γ

τµ (E-10)

Calculation for t = 120 min and T = 30oC :

79.149=•

γ s-1

:

55.31 =τ Pa → 69.23100079.149

55.31 == xµ cP

53.41 =τ Pa → 26.20100079.149

53.41 == xµ cP

53.41 =τ Pa → 26.20100079.149

53.41 == xµ cP

47.41 =τ Pa → 83.29100079.149

47.41 == xµ cP

47.41 =τ Pa → 83.29100079.149

47.41 == xµ cP

47.41 =τ Pa → 83.29100079.149

47.41 == xµ cP

47.41 =τ Pa → 83.29100079.149

47.41 == xµ cP

47.41 =τ Pa → 83.29100079.149

47.41 == xµ cP

53.41 =τ Pa → 26.30100079.149

53.41 == xµ cP

90

47.41 =τ Pa → 83.29100079.149

47.41 == xµ cP

Average viscosity at 79.149=•

γ s-1

:

10

83.2926.3083.2983.2983.2983.2983.2926.3026.3069.23 +++++++++=µ

3.29=µ cP

Calculation at different shear rate

•

γ for t = 120 minutes and T = 30oC is

provided Table E-6 to Table E-12.


, t = 120 min and T = 30oC

Data τ [Pa] •

γ [Hz] [ ]cPµ [ ]av cPµ

1 3.55 149.79 23.69

2 4.53 149.79 30.26

3 4.53 149.79 30.26

4 4.47 149.79 29.83

5 4.47 149.79 29.83

6 4.47 149.79 29.83

7 4.47 149.79 29.83

8 4.47 149.79 29.83

9 4.53 149.79 30.26

10 4.47 149.79 29.83

29.3


, t = 120 min and T = 30oC

Data τ [Pa] •


1 3.42 135.04 25.30

2 4.01 135.04 29.68

3 4.01 135.04 29.68

4 4.01 135.04 29.68

5 4.07 135.04 30.16

6 4.01 135.04 29.68

7 4.07 135.04 30.16

8 4.01 135.04 29.68

9 4.07 135.04 30.16

10 4.01 135.04 29.68

29.4

91


, t = 120 min and T = 30oC

Data τ [Pa] •


1 3.42 114.92 29.73

2 3.42 114.92 29.73

3 3.42 114.92 29.73

4 3.42 114.92 29.73

5 3.42 114.92 29.73

6 3.42 114.92 29.73

7 3.42 114.92 29.73

8 3.48 114.92 30.30

9 3.42 114.92 29.73

10 3.48 114.92 30.30

29.8


, t = 120 min and T = 30oC

Data τ [Pa] •


1 2.83 95.03 29.73

2 2.83 95.03 29.73

3 2.83 95.03 29.73

4 2.89 95.03 30.42

5 2.83 95.03 29.73

6 2.89 95.03 30.42

7 2.83 95.03 29.73

8 2.89 95.03 30.42

9 2.83 95.03 29.73

10 2.83 95.03 29.73

29.9


, t = 120min and T = 30oC

Data τ [Pa] •


1 2.30 74.89 30.70

2 2.23 74.89 29.83

3 2.30 74.89 30.70

4 2.23 74.89 29.83

5 2.30 74.89 30.70

6 2.23 74.89 29.83

7 2.23 74.89 29.83

8 2.30 74.89 30.70

9 2.23 74.89 29.83

10 2.23 74.89 29.83

30.2

92


, t = 120 min and T = 30oC

Data τ [Pa] •


1 1.71 55.00 31.06

2 1.58 55.00 28.67

3 1.64 55.00 29.86

4 1.58 55.00 28.67

5 1.71 55.00 31.06

6 1.64 55.00 29.86

7 1.58 55.00 28.67

8 1.71 55.00 31.06

9 1.58 55.00 28.67

10 1.64 55.00 29.86

29.7


, t = 120 min and T = 30oC

Data τ [Pa] •


1 0.79 29.95 26.32

2 0.85 29.95 28.52

3 0.99 29.95 32.91

4 1.12 29.95 37.29

5 0.92 29.95 30.71

6 0.72 29.95 24.13

7 1.05 29.95 35.10

8 0.79 29.95 26.32

9 0.92 29.95 30.71

10 1.12 29.95 37.29

30.9

Therefore, viscosity at reaction time (t) = 120 minutes and temperature (T) = 30oC:

9.297

9.307.292.309.298.294.293.29=

++++++=avµ cP

Viscositiy of polyols at different fixed reaction times and temperatures is determined

using the same calculation for viscosity at t = 120 minutes and T = 30oC

93

Calculation for t = 80 minutes and T = 40oC:


•

γ is provided Table E-13 to Table E-19.


, t = 80 min and T = 40oC

Data τ [Pa] •


1 4.47 149.79 29.83

2 5.32 149.79 35.53

3 5.26 149.79 35.09

4 5.26 149.79 35.09

5 5.32 149.79 35.53

6 5.26 149.79 35.09

7 5.26 149.79 35.09

8 5.32 149.79 35.53

9 5.26 149.79 35.09

10 5.26 149.79 35.09

34.7



Data τ [Pa] •


1 4.86 135.04 36.00

2 4.73 135.04 35.03

3 4.80 135.04 35.52

4 4.73 135.04 35.03

5 4.73 135.04 35.03

6 4.73 135.04 35.03

7 4.73 135.04 35.03

8 4.73 135.04 35.03

9 4.80 135.04 35.52

10 4.73 135.04 35.03

35.2

Table E-15Viscosity at shear rate 114.92 s-1


Data τ [Pa] •


1 3.48 114.92 30.30

2 4.01 114.92 34.87

3 4.07 114.92 35.44

4 4.01 114.92 34.87

5 4.01 114.92 34.87

6 4.01 114.92 34.87

7 4.01 114.92 34.87

8 4.01 114.92 34.87

9 4.07 114.92 35.44

10 4.07 114.92 35.44

34.6

94



Data τ [Pa] •


1 3.22 95.03 33.88

2 3.29 95.03 34.57

3 3.29 95.03 34.57

4 3.29 95.03 34.57

5 3.35 95.03 35.26

6 3.35 95.03 35.26

7 3.35 95.03 35.26

8 3.29 95.03 34.57

9 3.35 95.03 35.26

10 3.35 95.03 35.26

34.8



Data τ [Pa] •


1 2.76 74.89 36.84

2 2.69 74.89 35.97

3 2.63 74.89 35.09

4 2.69 74.89 35.97

5 2.63 74.89 35.09

6 2.63 74.89 35.09

7 2.69 74.89 35.97

8 2.63 74.89 35.09

9 2.63 74.89 35.09

10 2.63 74.89 35.09

35.5



Data τ [Pa] •


1 0.85 55.00 15.53

2 1.97 55.00 35.83

3 1.97 55.00 35.83

4 2.04 55.00 37.03

5 1.97 55.00 35.83

6 1.97 55.00 35.83

7 1.97 55.00 35.83

8 1.91 55.00 34.64

9 1.84 55.00 33.45

10 1.91 55.00 34.64

33.5

95



Data τ [Pa] •


1 0.92 29.95 30.71

2 0.92 29.95 30.71

3 1.05 29.95 35.10

4 0.92 29.95 30.71

5 0.72 29.95 24.13

6 1.18 29.95 39.49

7 1.18 29.95 39.49

8 1.05 29.95 35.10

9 1.05 29.95 35.10

10 0.46 29.95 15.36

31.6


3.347

6.315.335.358.346.342.357.34=

++++++=avµ cP

96



•



, t = 160 min and T = 40oC

Data τ [Pa] •


1 4.66 149.79 31.14

2 6.50 149.79 43.42

3 6.44 149.79 42.98

4 6.44 149.79 42.98

5 6.44 149.79 42.98

6 6.44 149.79 42.98

7 6.44 149.79 42.98

8 6.44 149.79 42.98

9 6.50 149.79 43.42

10 6.44 149.79 42.98

41.9


, t = 160 min and T = 40oC

Data τ [Pa] •


1 5.78 135.04 42.81

2 5.78 135.04 42.81

3 5.78 135.04 42.81

4 5.78 135.04 42.81

5 5.85 135.04 43.30

6 5.78 135.04 42.81

7 5.85 135.04 43.30

8 5.78 135.04 42.81

9 5.85 135.04 43.30

10 5.85 135.04 43.30

43.0


, t = 160 min and T = 40oC

Data τ [Pa] •


1 4.80 114.92 41.73

2 4.93 114.92 42.88

3 4.93 114.92 42.88

4 4.93 114.92 42.88

5 4.93 114.92 42.88

6 4.93 114.92 42.88

7 4.93 114.92 42.88

8 4.93 114.92 42.88

9 4.93 114.92 42.88

10 4.93 114.92 42.88

42.8

97


, t = 160 min and T = 40oC

Data τ [Pa] •


1 4.14 95.03 43.55

2 4.14 95.03 43.55

3 4.07 95.03 42.86

4 4.07 95.03 42.86

5 4.07 95.03 42.86

6 4.14 95.03 43.55

7 4.07 95.03 42.86

8 4.14 95.03 43.55

9 4.07 95.03 42.86

10 4.14 95.03 43.55

43.2


, t = 160 min and T = 40oC

Data τ [Pa] •


1 3.29 74.89 43.86

2 3.22 74.89 42.98

3 3.29 74.89 43.86

4 3.22 74.89 42.98

5 3.22 74.89 42.98

6 3.22 74.89 42.98

7 3.22 74.89 42.98

8 3.35 74.89 44.74

9 3.22 74.89 42.98

10 3.22 74.89 42.98

43.3


, t = 160 min and T = 40oC

Data τ [Pa] •


1 2.17 55.00 39.42

2 2.30 55.00 41.81

3 2.37 55.00 43.00

4 2.30 55.00 41.81

5 2.37 55.00 43.00

6 2.37 55.00 43.00

7 2.30 55.00 41.81

8 2.43 55.00 44.20

9 2.37 55.00 43.00

10 2.30 55.00 41.81

42.3

98


, t = 160 min and T = 40oC

Data τ [Pa] •


1 1.38 29.95 46.07

2 1.51 29.95 50.46

3 1.25 29.95 41.68

4 1.25 29.95 41.68

5 1.31 29.95 43.87

6 1.18 29.95 39.49

7 1.18 29.95 39.49

8 1.31 29.95 43.87

9 1.12 29.95 37.29

10 1.18 29.95 39.49

42.3


7.427

3.423.423.432.438.420.439.41=

++++++=avµ cP

99



•




Data τ [Pa] •


1 6.83 149.79 45.62

2 6.31 149.79 42.11

3 6.31 149.79 42.11

4 6.44 149.79 42.98

5 6.31 149.79 42.11

6 6.24 149.79 41.67

7 6.31 149.79 42.11

8 6.31 149.79 42.11

9 6.24 149.79 41.67

10 6.37 149.79 42.55

42.5



Data τ [Pa] •


1 4.93 135.04 36.49

2 5.65 135.04 41.84

3 5.72 135.04 42.33

4 5.65 135.04 41.84

5 5.65 135.04 41.84

6 5.65 135.04 41.84

7 5.58 135.04 41.35

8 5.65 135.04 41.84

9 5.72 135.04 42.33

10 5.72 135.04 42.33

41.4



Data τ [Pa] •


1 4.93 114.92 42.88

2 4.80 114.92 41.73

3 4.80 114.92 41.73

4 4.80 114.92 41.73

5 4.86 114.92 42.30

6 4.80 114.92 41.73

7 4.86 114.92 42.30

8 4.80 114.92 41.73

9 4.80 114.92 41.73

10 4.80 114.92 41.73

42.0

100



Data τ [Pa] •


1 3.94 95.03 41.48

2 4.01 95.03 42.17

3 4.01 95.03 42.17

4 4.01 95.03 42.17

5 4.01 95.03 42.17

6 4.01 95.03 42.17

7 3.94 95.03 41.48

8 4.01 95.03 42.17

9 4.01 95.03 42.17

10 4.01 95.03 42.17

42.0



Data τ [Pa] •


1 3.29 74.89 43.86

2 3.09 74.89 41.23

3 3.22 74.89 42.98

4 3.09 74.89 41.23

5 3.22 74.89 42.98

6 3.15 74.89 42.11

7 3.15 74.89 42.11

8 3.09 74.89 41.23

9 3.15 74.89 42.11

10 3.22 74.89 42.98

42.3



Data τ [Pa] •


1 1.51 55.00 27.47

2 2.30 55.00 41.81

3 2.30 55.00 41.81

4 2.30 55.00 41.81

5 2.43 55.00 44.20

6 2.23 55.00 40.61

7 2.30 55.00 41.81

8 2.30 55.00 41.81

9 2.30 55.00 41.81

10 2.37 55.00 43.00

40.6

101



Data τ [Pa] •


1 1.31 29.95 43.87

2 1.25 29.95 41.68

3 1.25 29.95 41.68

4 1.51 29.95 50.46

5 1.51 29.95 50.46

6 1.45 29.95 48.26

7 1.38 29.95 46.07

8 1.05 29.95 35.10

9 1.12 29.95 37.29

10 1.05 29.95 35.10

43.0


0.427

0.436.403.420.420.424.415.42=

++++++=avµ cP

102



•



, t = 120 min and T = 50oC

Data τ [Pa] •


1 12.88 149.79 85.97

2 6.70 149.79 44.74

3 6.77 149.79 45.18

4 6.83 149.79 45.62

5 6.70 149.79 44.74

6 6.83 149.79 45.62

7 6.83 149.79 45.62

8 6.77 149.79 45.18

9 6.70 149.79 44.74

10 6.77 149.79 45.18

49.3


, t = 120 min and T = 50oC

Data τ [Pa] •


1 6.44 139.96 46.00

2 6.31 139.96 45.07

3 6.37 139.96 45.54

4 6.31 139.96 45.07

5 6.24 139.96 44.60

6 6.24 139.96 44.60

7 6.31 139.96 45.07

8 6.24 139.96 44.60

9 6.31 139.96 45.07

10 6.18 139.96 44.13

45.0


, t = 120 min and T = 50oC

Data τ [Pa] •


1 4.99 110.01 45.39

2 4.93 110.01 44.79

3 4.86 110.01 44.20

4 4.86 110.01 44.20

5 4.86 110.01 44.20

6 4.86 110.01 44.20

7 4.86 110.01 44.20

8 4.86 110.01 44.20

9 4.86 110.01 44.20

10 4.86 110.01 44.20

44.4

103


, t = 120 min and T = 50oC

Data τ [Pa] •


1 3.81 84.95 44.86

2 3.74 84.95 44.08

3 3.74 84.95 44.08

4 3.81 84.95 44.86

5 3.74 84.95 44.08

6 3.74 84.95 44.08

7 3.74 84.95 44.08

8 3.74 84.95 44.08

9 3.74 84.95 44.08

10 3.74 84.95 44.08

44.2


, t = 120 min and T = 50oC

Data τ [Pa] •


1 3.29 74.89 43.86

2 3.22 74.89 42.98

3 3.29 74.89 43.86

4 3.15 74.89 42.11

5 3.22 74.89 42.98

6 3.15 74.89 42.11

7 3.22 74.89 42.98

8 3.22 74.89 42.98

9 3.22 74.89 42.98

10 3.22 74.89 42.98

43.0


, t = 120 min and T = 50oC

Data τ [Pa] •


1 2.17 50.09 43.29

2 2.10 50.09 41.98

3 2.23 50.09 44.60

4 1.97 50.09 39.35

5 2.30 50.09 45.91

6 1.97 50.09 39.35

7 2.23 50.09 44.60

8 2.17 50.09 43.29

9 2.17 50.09 43.29

10 2.17 50.09 43.29

42.9

104


, t = 120 min and T = 50oC

Data τ [Pa] •


1 0.26 25.05 10.49

2 1.31 25.05 52.45

3 0.79 25.05 31.47

4 0.99 25.05 39.33

5 0.72 25.05 28.85

6 0.99 25.05 39.33

7 0.99 25.05 39.33

8 0.99 25.05 39.33

9 0.79 25.05 31.47

10 0.79 25.05 31.47

34.4


3.437

4.349.420.433.444.440.453.49=

++++++=avµ cP

105



•



, t = 200 min and T = 50oC

Data τ [Pa] •


1 5.32 149.79 35.53

2 7.03 149.79 46.93

3 7.03 149.79 46.93

4 7.10 149.79 47.37

5 7.03 149.79 46.93

6 7.03 149.79 46.93

7 7.10 149.79 47.37

8 7.03 149.79 46.93

9 6.96 149.79 46.49

10 6.96 149.79 46.49

45.8


, t = 200 min and T = 50oC

Data τ [Pa] •


1 6.24 135.04 46.22

2 6.24 135.04 46.22

3 6.31 135.04 46.71

4 6.24 135.04 46.22

5 6.31 135.04 46.71

6 6.31 135.04 46.71

7 6.24 135.04 46.22

8 6.31 135.04 46.71

9 6.24 135.04 46.22

10 6.24 135.04 46.22

46.4


, t = 200 min and T = 50oC

Data τ [Pa] •


1 5.45 114.92 47.45

2 5.32 114.92 46.31

3 5.32 114.92 46.31

4 5.32 114.92 46.31

5 5.39 114.92 46.88

6 5.32 114.92 46.31

7 5.45 114.92 47.45

8 5.32 114.92 46.31

9 5.32 114.92 46.31

10 5.39 114.92 46.88

46.7

106


, t = 200 min and T = 50oC

Data τ [Pa] •


1 4.53 95.03 47.70

2 4.40 95.03 46.32

3 4.47 95.03 47.01

4 4.40 95.03 46.32

5 4.47 95.03 47.01

6 4.40 95.03 46.32

7 4.47 95.03 47.01

8 4.40 95.03 46.32

9 4.47 95.03 47.01

10 4.40 95.03 46.32

46.7


, t = 200 min and T = 50oC

Data τ [Pa] •


1 3.61 74.89 48.25

2 3.61 74.89 48.25

3 3.48 74.89 46.49

4 3.55 74.89 47.37

5 3.48 74.89 46.49

6 3.48 74.89 46.49

7 3.55 74.89 47.37

8 3.42 74.89 45.62

9 3.55 74.89 47.37

10 3.48 74.89 46.49

47.0


, t = 200 min and T = 50oC

Data τ [Pa] •


1 1.58 55.00 28.67

2 2.56 55.00 46.58

3 2.50 55.00 45.39

4 2.56 55.00 46.58

5 2.63 55.00 47.78

6 2.56 55.00 46.58

7 2.56 55.00 46.58

8 2.50 55.00 45.39

9 2.63 55.00 47.78

10 2.63 55.00 47.78

44.9

107


, t = 200 min and T = 50oC

Data τ [Pa] •


1 1.64 29.95 54.84

2 1.71 29.95 57.04

3 1.58 29.95 52.65

4 1.38 29.95 46.07

5 1.45 29.95 48.26

6 1.38 29.95 46.07

7 1.45 29.95 48.26

8 2.17 29.95 72.39

9 1.71 29.95 57.04

10 1.58 29.95 52.65

53.5


3.477

5.539.440.477.467.464.468.45=

++++++=avµ cP

108



•

γ is provided Table E-48 to Table 54.



Data τ [Pa] •


1 4.93 149.79 32.90

2 6.24 149.79 41.67

3 6.31 149.79 42.11

4 6.44 149.79 42.98

5 6.31 149.79 42.11

6 6.44 149.79 42.98

7 6.31 149.79 42.11

8 6.31 149.79 42.11

9 6.31 149.79 42.11

10 6.37 149.79 42.55

41.4



Data τ [Pa] •


1 4.93 114.92 42.88

2 4.86 114.92 42.30

3 4.86 114.92 42.30

4 4.86 114.92 42.30

5 4.93 114.92 42.88

6 4.86 114.92 42.30

7 4.93 114.92 42.88

8 4.93 114.92 42.88

9 4.93 114.92 42.88

10 4.93 114.92 42.88

42.7



Data τ [Pa] •


1 3.35 74.89 44.74

2 3.15 74.89 42.11

3 3.29 74.89 43.86

4 3.22 74.89 42.98

5 3.29 74.89 43.86

6 3.15 74.89 42.11

7 3.29 74.89 43.86

8 3.22 74.89 42.98

9 3.29 74.89 43.86

10 3.29 74.89 43.86

43.4

109



Data τ [Pa] •


1 1.77 29.95 59.23

2 1.64 29.95 54.84

3 1.38 29.95 46.07

4 1.51 29.95 50.46

5 1.18 29.95 39.49

6 1.25 29.95 41.68

7 1.45 29.95 48.26

8 1.25 29.95 41.68

9 1.31 29.95 43.87

10 1.18 29.95 39.49

46.5



Data τ [Pa] •


1 4.07 135.04 30.16

2 5.85 135.04 43.30

3 5.85 135.04 43.30

4 5.85 135.04 43.30

5 5.91 135.04 43.79

6 5.85 135.04 43.30

7 5.91 135.04 43.79

8 5.85 135.04 43.30

9 5.98 135.04 44.27

10 5.91 135.04 43.79

42.2



Data τ [Pa] •


1 4.34 95.03 45.63

2 4.14 95.03 43.55

3 4.20 95.03 44.25

4 4.20 95.03 44.25

5 4.20 95.03 44.25

6 4.20 95.03 44.25

7 4.20 95.03 44.25

8 4.20 95.03 44.25

9 4.20 95.03 44.25

10 4.20 95.03 44.25

44.3

110



Data τ [Pa] •


1 2.56 55.00 46.58

2 2.43 55.00 44.20

3 2.50 55.00 45.39

4 2.43 55.00 44.20

5 2.56 55.00 46.58

6 2.63 55.00 47.78

7 2.50 55.00 45.39

8 2.56 55.00 46.58

9 2.50 55.00 45.39

10 2.50 55.00 45.39

45.8


8.437

8.454.442.425.464.437.424.41=

++++++=avµ cP

111

Calculation for t =160 minutes and T = 60oC:


•



, t = 160 min and T = 60oC

Data τ [Pa] •


1 8.02 149.79 53.51

2 9.20 149.79 61.41

3 9.26 149.79 61.84

4 9.20 149.79 61.41

5 9.13 149.79 60.97

6 9.13 149.79 60.97

7 9.20 149.79 61.41

8 9.07 149.79 60.53

9 9.07 149.79 60.53

10 9.20 149.79 61.41

60.4


, t = 160 min and T = 60oC

Data τ [Pa] •


1 8.48 135.04 62.76

2 8.28 135.04 61.30

3 8.21 135.04 60.82

4 8.28 135.04 61.30

5 8.21 135.04 60.82

6 8.21 135.04 60.82

7 8.21 135.04 60.82

8 8.21 135.04 60.82

9 8.21 135.04 60.82

10 8.34 135.04 61.79

61.2


, t = 160 min and T = 60oC

Data τ [Pa] •


1 6.90 114.92 60.03

2 6.96 114.92 60.60

3 6.96 114.92 60.60

4 7.03 114.92 61.17

5 7.03 114.92 61.17

6 7.03 114.92 61.17

7 7.03 114.92 61.17

8 7.03 114.92 61.17

9 7.03 114.92 61.17

10 7.03 114.92 61.17

60.9

112


, t = 160 min and T = 60oC

Data τ [Pa] •


1 5.32 95.03 56.00

2 5.91 95.03 62.22

3 5.78 95.03 60.84

4 5.85 95.03 61.53

5 5.78 95.03 60.84

6 5.85 95.03 61.53

7 5.78 95.03 60.84

8 5.85 95.03 61.53

9 5.78 95.03 60.84

10 5.85 95.03 61.53

60.8


, t = 160 min and T = 60oC

Data τ [Pa] •


1 4.20 74.89 56.14

2 4.60 74.89 61.41

3 4.73 74.89 63.16

4 4.60 74.89 61.41

5 4.60 74.89 61.41

6 4.66 74.89 62.28

7 4.66 74.89 62.28

8 4.66 74.89 62.28

9 4.60 74.89 61.41

10 4.73 74.89 63.16

61.5


, t = 160 min and T = 60oC

Data τ [Pa] •


1 2.69 55.00 48.97

2 3.35 55.00 60.92

3 3.48 55.00 63.31

4 3.42 55.00 62.11

5 3.55 55.00 64.50

6 3.42 55.00 62.11

7 3.42 55.00 62.11

8 3.48 55.00 63.31

9 3.35 55.00 60.92

10 3.48 55.00 63.31

61.2

113


, t = 160 min and T = 60oC

Data τ [Pa] •


1 1.91 29.95 63.62

2 2.04 29.95 68.01

3 2.17 29.95 72.39

4 2.10 29.95 70.20

5 1.97 29.95 65.81

6 1.91 29.95 63.62

7 2.04 29.95 68.01

8 1.97 29.95 65.81

9 1.77 29.95 59.23

10 1.84 29.95 61.42

65.8


7.617

8.652.615.618.609.602.614.60=

++++++=avµ cP

114



•

γ is provided Table E-62 to Table E-68


, t = 120 min and T = 70oC

Data τ [Pa] •


1 17.74 149.79 118.43

2 14.65 149.79 97.81

3 14.39 149.79 96.06

4 14.52 149.79 96.93

5 14.52 149.79 96.93

6 14.45 149.79 96.50

7 14.32 149.79 95.62

8 14.59 149.79 97.37

9 14.45 149.79 96.50

10 14.39 149.79 96.06

98.8


, t = 120 min and T = 70oC

Data τ [Pa] •


1 13.07 135.04 96.82

2 13.01 135.04 96.33

3 13.01 135.04 96.33

4 12.94 135.04 95.85

5 13.01 135.04 96.33

6 12.94 135.04 95.85

7 13.01 135.04 96.33

8 12.94 135.04 95.85

9 13.01 135.04 96.33

10 12.94 135.04 95.85

96.2


, t = 120 min and T = 70oC

Data τ [Pa] •


1 11.50 114.92 100.04

2 11.04 114.92 96.04

3 10.97 114.92 95.47

4 11.04 114.92 96.04

5 10.97 114.92 95.47

6 10.97 114.92 95.47

7 11.04 114.92 96.04

8 10.97 114.92 95.47

9 11.04 114.92 96.04

10 10.97 114.92 95.47

96.2

115


, t = 120 min and T = 70oC

Data τ [Pa] •


1 9.13 95.03 96.10

2 9.07 95.03 95.41

3 9.07 95.03 95.41

4 9.20 95.03 96.79

5 9.07 95.03 95.41

6 9.13 95.03 96.10

7 9.07 95.03 95.41

8 9.13 95.03 96.10

9 9.07 95.03 95.41

10 9.20 95.03 96.79

95.9


, t = 120 min and T = 70oC

Data τ [Pa] •


1 6.64 74.89 88.60

2 7.10 74.89 94.74

3 7.23 74.89 96.50

4 7.10 74.89 94.74

5 7.16 74.89 95.62

6 7.23 74.89 96.50

7 7.16 74.89 95.62

8 7.03 74.89 93.86

9 7.03 74.89 93.86

10 7.29 74.89 97.37

94.7


, t = 120 min and T = 70oC

Data τ [Pa] •


1 4.73 55.00 86.00

2 5.19 55.00 94.36

3 5.26 55.00 95.56

4 5.19 55.00 94.36

5 5.32 55.00 96.75

6 5.19 55.00 94.36

7 5.26 55.00 95.56

8 5.26 55.00 95.56

9 5.06 55.00 91.97

10 5.26 55.00 95.56

94.0

116


, t = 120 min and T = 70oC

Data τ [Pa] •


1 2.96 29.95 98.72

2 2.76 29.95 92.14

3 2.76 29.95 92.14

4 2.69 29.95 89.94

5 2.89 29.95 96.52

6 2.69 29.95 89.94

7 2.76 29.95 92.14

8 2.63 29.95 87.75

9 2.69 29.95 89.94

10 2.56 29.95 85.56

91.5


3.957

5.910.947.949.952.962.968.98=

++++++=avµ cP

117



•



, t = 120 min and T = 50oC

Data τ [Pa] •


1 12.55 149.79 83.78

2 6.77 149.79 45.18

3 6.83 149.79 45.62

4 6.90 149.79 46.05

5 6.83 149.79 45.62

6 6.90 149.79 46.05

7 6.90 149.79 46.05

8 6.77 149.79 45.18

9 6.83 149.79 45.62

10 6.77 149.79 45.18

49.4


, t = 120 min and T = 50oC

Data τ [Pa] •


1 6.24 135.04 46.22

2 6.11 135.04 45.25

3 6.18 135.04 45.73

4 6.11 135.04 45.25

5 6.11 135.04 45.25

6 6.11 135.04 45.25

7 6.11 135.04 45.25

8 6.11 135.04 45.25

9 6.18 135.04 45.73

10 6.11 135.04 45.25

45.4


, t = 120 min and T = 50oC

Data τ [Pa] •


1 4.60 114.92 40.02

2 5.19 114.92 45.16

3 5.19 114.92 45.16

4 5.19 114.92 45.16

5 5.19 114.92 45.16

6 5.19 114.92 45.16

7 5.12 114.92 44.59

8 5.19 114.92 45.16

9 5.19 114.92 45.16

10 5.19 114.92 45.16

44.6

118


, t = 120 min and T = 50oC

Data τ [Pa] •


1 4.40 95.03 46.32

2 4.27 95.03 44.94

3 4.34 95.03 45.63

4 4.34 95.03 45.63

5 4.34 95.03 45.63

6 4.27 95.03 44.94

7 4.34 95.03 45.63

8 4.27 95.03 44.94

9 4.34 95.03 45.63

10 4.27 95.03 44.94

45.4


, t = 120 min and T = 50oC

Data τ [Pa] •


1 3.29 74.89 43.86

2 3.42 74.89 45.62

3 3.35 74.89 44.74

4 3.42 74.89 45.62

5 3.35 74.89 44.74

6 3.35 74.89 44.74

7 3.42 74.89 45.62

8 3.35 74.89 44.74

9 3.42 74.89 45.62

10 3.42 74.89 45.62

45.1


, t = 120 min and T = 50oC

Data τ [Pa] •


1 2.63 55.00 47.78

2 2.50 55.00 45.39

3 2.43 55.00 44.20

4 2.50 55.00 45.39

5 2.43 55.00 44.20

6 2.37 55.00 43.00

7 2.56 55.00 46.58

8 2.37 55.00 43.00

9 2.43 55.00 44.20

10 2.37 55.00 43.00

44.7

119


, t = 120 min and T = 50oC

Data τ [Pa] •


1 0.33 29.95 10.97

2 1.45 29.95 48.26

3 1.31 29.95 43.87

4 1.12 29.95 37.29

5 1.38 29.95 46.07

6 1.64 29.95 54.84

7 1.18 29.95 39.49

8 1.38 29.95 46.07

9 1.25 29.95 41.68

10 1.25 29.95 41.68

41.0


1.457

0.417.441.454.456.444.454.49=

++++++=avµ cP

120



•



, t = 120 min and T = 50oC

Data τ [Pa] •


1 4.66 149.79 31.14

2 6.64 149.79 44.30

3 6.57 149.79 43.86

4 6.70 149.79 44.74

5 6.64 149.79 44.30

6 6.64 149.79 44.30

7 6.64 149.79 44.30

8 6.57 149.79 43.86

9 6.57 149.79 43.86

10 6.64 149.79 44.30

42.9


, t = 120 min and T = 50oC

Data τ [Pa] •


1 6.18 135.04 45.73

2 5.91 135.04 43.79

3 5.98 135.04 44.27

4 5.91 135.04 43.79

5 5.98 135.04 44.27

6 5.98 135.04 44.27

7 5.91 135.04 43.79

8 5.98 135.04 44.27

9 5.91 135.04 43.79

10 5.98 135.04 44.27

44.2


, t = 120 min and T = 50oC

Data τ [Pa] •


1 5.32 114.92 46.31

2 5.06 114.92 44.02

3 5.06 114.92 44.02

4 5.06 114.92 44.02

5 5.06 114.92 44.02

6 5.06 114.92 44.02

7 5.06 114.92 44.02

8 5.06 114.92 44.02

9 5.06 114.92 44.02

10 5.06 114.92 44.02

44.3

121


, t = 120 min and T = 50oC

Data τ [Pa] •


1 4.27 95.03 44.94

2 4.14 95.03 43.55

3 4.27 95.03 44.94

4 4.14 95.03 43.55

5 4.20 95.03 44.25

6 4.20 95.03 44.25

7 4.20 95.03 44.25

8 4.20 95.03 44.25

9 4.20 95.03 44.25

10 4.14 95.03 43.55

44.2


, t = 120 min and T = 50oC

Data τ [Pa] •


1 3.29 74.89 43.86

2 3.22 74.89 42.98

3 3.29 74.89 43.86

4 3.29 74.89 43.86

5 3.35 74.89 44.74

6 3.22 74.89 42.98

7 3.42 74.89 45.62

8 3.29 74.89 43.86

9 3.35 74.89 44.74

10 3.29 74.89 43.86

44.0


, t = 120 min and T = 50oC

Data τ [Pa] •


1 2.50 55.00 45.39

2 2.50 55.00 45.39

3 2.43 55.00 44.20

4 2.50 55.00 45.39

5 2.43 55.00 44.20

6 2.43 55.00 44.20

7 2.50 55.00 45.39

8 2.50 55.00 45.39

9 2.43 55.00 44.20

10 2.56 55.00 46.58

45.0

122


, t = 120 min and T = 50oC

Data τ [Pa] •


1 1.51 29.95 50.46

2 1.51 29.95 50.46

3 1.45 29.95 48.26

4 1.45 29.95 48.26

5 1.51 29.95 50.46

6 1.25 29.95 41.68

7 1.38 29.95 46.07

8 1.38 29.95 46.07

9 1.38 29.95 46.07

10 1.18 29.95 39.49

46.7


5.447

7.460.450.442.443.442.449.42=

++++++=avµ cP

the synthesis of polyol from rice bran oil (rbo) through

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