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Journal of the American Oil Chemists'Society ISSN 0003-021X J Am Oil Chem SocDOI 10.1007/s11746-013-2275-3

Synthesis of Bio-based Polyurethane fromModified Prosopis juliflora Oil

Dipak S. Tathe & Ramanand N. Jagtap

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ORIGINAL PAPER

Synthesis of Bio-based Polyurethane from Modified Prosopisjuliflora Oil

Dipak S. Tathe • Ramanand N. Jagtap

Received: 12 January 2013 / Revised: 8 May 2013 / Accepted: 14 May 2013

� AOCS 2013

Abstract Studies on the epoxidation of Prosopis juliflora

seed oil were carried out to evaluate the optimum level of

oxirane formation. On optimization of epoxidation of

Prosopis juliflora oil (PJO), it was observed that at 60 �C and

the mole ratio of double bond to the hydrogen peroxide to the

acetic acid was 1:1.1:0.5 and at 2 wt% catalyst loading gave

the maximum oxirane conversion. Further, epoxidized

Prosopis juliflora oil (EPJO) was reacted with aminopro-

pyltrimethoxysilane. Aminopropyltrimethoxysilanated Pros-

opis juliflora oil (ASPJO) was used as a polyol and was

allowed to react with varying concentrations of isophorone

diisocyanate resulting in polyurethane. The polyurethane

films biodegradability was studied using phosphate buffer and

proteinase K. The epoxidized oil was characterized by its

epoxy value and FT-IR spectroscopy. Similarly, ASPJO was

characterized by its amine value, FT-IR and 1H-NMR spec-

troscopy. Whereas the polyurethane coating was character-

ized by gel content, FT-IR spectroscopy, scanning electron

microscopic analysis and also evaluated for its chemical

resistance, optical and mechanical properties.

Keywords Epoxidation � Prosopis juliflora seed oil �Aminopropyltrimethoxysilane � Isophorone diisocyanate �Biodegradation

Introduction

Abatement of petroleum sources, growing environmental

awareness and new rules and regulations are forcefully

demanding researchers and industries to seek more eco-

friendly materials for their research and applications [1–4].

Recently, polymers which are developed from renewable

resources have attracted attention to a great extent due to

their environmental and economic advantages. Among

them, vegetable oils are easily available in large quantities,

environmentally friendly and biodegradable. In addition,

they are of low cost, easy to modify and safe to handle [5–

8]. Vegetable oils contain triglyceride structures, which

have several reactive positions that enable chemical reac-

tions: through ester groups, C=C double bonds, allylic

positions and the a-position of the ester groups. These can

be used to polymerize triglycerides directly or to modify

the triglyceride structure with polymerizable groups to

obtain thermosets [8–11].

A variety of industrial products are derived from vege-

table oils including coatings, inks, plasticizers and lubri-

cants [12–15]. Vegetable oils have some limitations in

coating, but after modification with a suitable functional

group they can be converted into valuable products with

better properties [16]. Significant progress has been made

in the development of chemical methods for enhancing the

functionality of oils [17, 18].

In the present work, we enhanced the coating properties of

Prosopis juliflora oil (PJO) by modification with amino-

propyltrimethoxysilane (APTS) and isophorone diisocya-

nate (IPDI) and studied the coating properties of the resultant

polyurethane. We also studied the optimum conditions for

higher oxirane formation. According to the literature, PJO

had not yet been epoxidized, so there was a need to study the

optimum conditions for higher oxirane formation for further

reaction to obtain a maximum hydroxyl value after the ring

opening reaction for polyurethane synthesis.

Organofunctional silane enhances the adhesion of

coating. It also acts as a surface modifier and a cross

D. S. Tathe � R. N. Jagtap (&)

Department of Polymer and Surface Engineering,

Institute of Chemical Technology, Mumbai 400 019, India

e-mail: [email protected]

123

J Am Oil Chem Soc

DOI 10.1007/s11746-013-2275-3

Author's personal copy

linking agent. Organofunctional silanes that are attached to

the polymer help to cross-link the polymer by reacting with

moisture [19, 20]. Polyurethanes from vegetable oils have

found great application in the area of coating because they

posses good mechanical strength, excellent abrasion

resistance, toughness, and chemical resistance [21–26].

Experimental

Materials

Prosopis juliflora seeds were collected from their indige-

nous origin (Vidarbha, Maharashtra.) Hydrogen peroxide

(50 %), glacial acetic acid, sulfuric acid, sodium sulfate,

diethyl ether and sodium bicarbonate, di-potassium

hydrogen orthophosphate, potassium dihydrogen ortho-

phosphate, sodium azide and proteinase K were purchased

from SD Fine-Chem. Ltd., APTS was procured from

Wacker Chemie Pvt. Ltd., IPDI was collected from Bayer

Material Science, dibutyltin dilaurate was purchased from

Otto-Chemie Pvt. Ltd. All reagents were used without

further purification.

Extraction of Prosopis juliflora Seed Oil

Prosopis juliflora seeds were air-dried; ground to a powder

and then the oil was extracted by Soxhlet extraction

method using petroleum ether (B.P. 60–80 �C) as the sol-

vent. Fatty acid methyl esters (FAME) of PJO were pre-

pared by AOCS official method Ce 2-66 (1992) and fatty

acid composition was analyzed according to AOCS official

method Ce 1-62 (1997) and [27]. The fatty acid composi-

tion of PJO is myristic acid (14:0) 0.3 %, palmitic acid

(16:0) 11.5 %, stearic acid (18:0) 5.0 %, oleic acid (18:1)

24.5 %, linoleic acid (18:2) 50.2 %, linolenic acid (18:3)

1.7 %, eicosenoic acid (20:1) 0.6 %, arachidic acid (20:0)

2.6 %, erucic acid (22:1) 0.3 %, behenic acid (22:0) 2.2 %,

lignoceric acid (24:0) 1.3 %.

Epoxidation of PJO

The reaction was carried out according to the procedure

given in [9]. A three-necked round-bottom flask, equipped

with a mechanical stirrer, condenser and thermometer

pocket was used. First, 20 g PJO, glacial acetic acid (varied

from 0.25 to 0.75 mol/mol of the double bond of PJO) and

H2SO4 (varied from 1 to 3 wt% of the total weight of

glacial acetic acid and hydrogen peroxide) were placed in a

three-necked round-bottom flask. Hydrogen peroxide

(50 %) (varied from 1.1 to 2 mol/mol of double bond of

PJO) was added drop wise for half an hour into the reaction

mixture at 25 �C. Reaction progress was monitor by mea-

suring the epoxy value at regular intervals. After the

completion of reaction, the product was washed with water;

the organic phase was extracted in diethyl ether and dried

over anhydrous sodium sulfate.

Synthesis of ASPJO

Ten grams of pre-dried epoxidized Prosopis juliflora oil

(EPJO) was poured into the two-necked round-bottom flask

equipped with a condenser and guard tube. Then 5.14 g

APTS was added to the flask. Nitrogen gas was flushed

through the reaction setup and inert conditions were main-

tained. The reaction mixture was heated in an oil bath with a

magnetic stirrer for 3 h at 110 �C. The reaction was monitor

by FT-IR, when epoxy stretching at 823 cm-1 was found to

be absent, its amine value was determined. The reaction of

the synthesis of aminopropyltrimethoxysilanated Prosopis

juliflora oil (ASPJO) is shown in Fig. 1.

Reaction of ASPJO with IPDI

Ten grams of ASPJO, 4.266 g IPDI (the NCO to OH mole

ratio was 1), 14.226 g xylene and DBTDL (0.01 wt% of

IPDI) were put into the 100-ml, three-necked round-bottom

flask equipped with a mechanical stirrer, condenser and

nitrogen inlet. Then it was stirred for 30 min to obtain

sufficient viscosity. Then the material was removed from

the reactor and applied onto the metal panels (3 9 5 in)

using a bar applicator at DFT 100 lm. These coated panels

were placed at ambient temperature for 1 h and then in the

air circulating oven at 80 �C for 8 h to attained a suffi-

ciently fast cross-linking of silane. The same procedure

was followed for the various NCO to OH mole ratios (0.8,

0.6, 0.4 and 0.2). The reaction of ASPJO with IPDI is

shown in Fig. 1.

Methods

Fatty acid methyl esters (FAME) of PJO were prepared by

AOCS official method Ce 2-66 (1992) and the fatty acid

composition was analyzed according to AOCS official

method Ce 1-62 (1997). FAME were analyzed by GC-FID.

A SHIMADZU GC-17-A-gas chromatograph with a flame

ionization detector (FID) was used. FAME were separated

on a CHROMPACK WCOT 25 m 9 0.25 mm ID, 0.2 lm

film thickness capillary column using a temperature pro-

gramme from 150 �C/5 min, increasing at 4 �C/min until

235 �C and 50 min at 235 �C under the following condi-

tions: injector temperature 260 �C, FID temperature 260 �C

and the carrier gas was helium.

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FT-IR spectra (Shimadzu 8400S, Japan) of PJO, EPJO,

ASPJO and cured polymer films were recorded by using

the ATR technique.

The 1H-NMR spectrum of ASPJO was recorded at

400 MHz using Bruker Biospin (Avance AV500WB,

Germany) using deuterated chloroform as the solvent and

tetramethylsilane (TMS) as an internal standard.

The surface morphology of the cured film was studied

with a scanning electron microscope (SEM) (JEOL JSM-

6380LA). Rectangular pieces of approximately 2.5 9 1

mm where cut with a razor blade from the crack. Samples

were exposed overnight in a vacuum oven under the con-

ditions of room temperature and 100 mmHg. Then, these

were mounted on an aluminium stub and analyzed.

The iodine value was determined according to the Wijs

method by using iodine monochloride solution in acetic

acid and carbon tetrachloride and determination of the

excess halogen by addition of KI solution and titration of

the liberated iodine with sodium thiosulfate (ASTM D

1959-97).

The percentage oxirane oxygen was determined by a

direct method using hydrobromic acid solution in glacial

acetic acid [28]. From the oxirane content values, the rel-

ative percentage conversion to oxirane was calculated

using the following expression:

Relative percentage conversion to oxirane

¼ OOexp=OOthe

� �� 100;

where OOexp (g/100 g sample) is the experimentally

obtained oxirane oxygen and OOthe is the theoretically

obtainable maximum oxirane oxygen, which was

determined from the following expression:

OOthe ¼ IV0=2Aið Þ=100þ IV0=2Aið ÞAo½ �Ao � 100;

where Ai (126.9) and Ao (16.0) are the atomic weights of

iodine and oxygen respectively and IV0 is the initial iodine

value of the PJO oil.

The amine value was determined by using the ASTM D

2074-92 method, by boiling the sample with alcohol and

then titrating with HCl in the presence of bromphenol blue

indicator.

The hydroxyl value was determined by using the ASTM

D 1957-86 method, by refluxing the sample with a pyri-

dine-acetic anhydride mixture and then titrated with KOH

in the presence of a phenolphthalein indicator.

The gloss of the cured films was measured on a cali-

brated instrument at a 60� angle of reflectance using a

digital mini gloss meter (Rhopoint Instruments, ASTM D

523-99). This test method covers the measurement of the

specular gloss of specimens for glossmeter geometries of

60�, the values stated in inch-pound units are to be regar-

ded as the standard.

The contact angle of the cured polymer film applied on

metal panel was measured by a Kruss G10 Goniometer, the

contact angle was measured by using DI water.

The cured film was carefully peeled off from the glass

plate, in order to measure the gel content, a known weight

of the cured film was extracted in xylene at room tem-

perature for 24 h. The residue was dried at 70 �C in order

to get a constant weight. The gel content of the cured film

was then determined by the equation: Gel content

(%) = Wt/W0 9 100. Where, Wt is the weight after

extraction and W0 is the weight before extraction.

Impact resistance measurement was carried out on both

sides of the coated metal panels and analyzed in accor-

dance with the standard ASTM D 2794 method. This test

method covers a procedure for rapidly deforming by

impact a coating film and its substrate and for evaluating

the effect of such deformation.

The hardness of the coating which had been applied onto

the metal panel was measured by the pencil hardness test

according to ASTM D 3363. This test method covers a

procedure for rapid, inexpensive determination of the film

Fig. 1 Synthesis of a bio-based polyurethane

J Am Oil Chem Soc

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hardness of an organic coating on a substrate in terms of

drawing leads or pencil leads of known hardness.

The scratch hardness was determined by the automatic

scratch hardness tester as per ASTM D7027. This test

method gives the hardness of an organic coating on a

substrate by increasing the weight in an automatic scratch

hardness tester.

The solvent resistance of the coating was determined by

ASTM D 5402–93 using a solvent rub technique for

assessing the solvent resistance of an organic coating by

rubbing the coating with a cloth saturated with the appro-

priate solvent.

An adhesion test was performed by a crosscut adhesion

tester used to check the adhesion of the coated film to

metallic substrate, according to ASTM D 3359.

The alkali resistance of coated metal panels was eval-

uated for film whitening and blistering according to ASTM

D 1647, by dipping the coated panel in 3 % aqueous

solution of sodium hydroxide for 24 h.

The acid resistance of the panels was evaluated for

peeling and corrosion of the coated part according to

ASTM D 3260, by dipping the coated panel in a ten vol-

ume percent solution of hydrochloric acid (31.8 % HCl) in

distilled water for 6 h.

Water resistance was measured by immersing the coated

panels in water, the panels were evaluated for color change

of the coating, blistering, and skinning according to ASTM

D 870-02.

The flexibility of the coated metal panel was determined

by the conical mandrel according to ASTM D 522-93a.

These test methods cover the determination of the resis-

tance to cracking (flexibility) of attached organic coatings

on substrates of metal.

Results and Discussion

Effect of Temperature on Oxirane Formation

To study the effect of temperature on the epoxidation rate,

H2O2 to double bond mole ratio 1.1, CH3COOH to double

bond mole ratio 0.5 and 2 wt% concentrated H2SO4 were

added with PJO and the runs were taken at different tem-

peratures in the range 30–80 �C. The oxirane value con-

versions are shown in Fig. 2. It was found that as the

temperature increases, the epoxidation rate increases. But

at a temperature greater than 60 �C initially, there was a

good oxirane conversion, and after a certain time limit the

oxirane conversion decreased. However, at 60 �C, the

relative percentage conversion to oxirane attained a max-

imum. This indicates that an increase in temperature not

only increases the epoxidation rate but also increases the

rate of epoxy ring opening.

Effect of H2SO4 Concentration on Oxirane Formation

To study the effect of the H2SO4 concentration on the

epoxidation reaction, H2O2 to double bond mole ratio 1.1,

CH3COOH to double bond mole ratio 0.5 were added with

PJO at 60 �C and the concentration of H2SO4 was varied

from 1 to 3 wt%. The maximum conversion of oxirane was

found at 2 wt% of H2SO4 concentration, but when H2SO4

loading increased up to 3 wt%, it caused epoxy ring

opening reaction. The optimum conversion to oxirane was

obtained at 2 wt% loading of H2SO4 is shown in Fig. 3.

Effect of Acetic Acid Concentration on Oxirane

Formation

To study the effect of acetic acid concentration of epoxida-

tion rate, H2O2 to double bond mole ratio 1.1 and 2 wt%

concentrated H2SO4 were added with PJO at 60 �C and

concentration of acetic acid was varied from 0.25 to

0.75 mol/mol of double bond. The oxirane value conver-

sions are given in Fig. 4. It was observed that the epoxidation

Fig. 2 Effect of temperature on relative percentage conversion to

oxirane. Conditions: mole ratio double bond as to H2O2 to CH3COOH

was 1 as to 1.1 to 0.5 respectively and H2SO4 = 2 %

Fig. 3 Effect of H2SO4 concentration on relative percentage

conversion to oxirane. Conditions: temperature 60 ± 1 �C; mole

ratio double bond as to H2O2 as to CH3COOH was 1 as to 1.1 to 0.5

respectively

J Am Oil Chem Soc

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rate increased as the concentration of acetic acid in the sys-

tem increased, but at a higher mole ratio of acetic acid, the

oxirane ring opening reaction was also increased.

Effect of Hydrogen Peroxide Concentration on Oxirane

Formation

To study the effect of hydrogen peroxide concentration on

the epoxidation rate, glacial acetic acid to double bond

mole ratio 0.5 and 2 wt% concentrated H2SO4 were added

with PJO at 60 �C and the concentration of hydrogen

peroxide was varied from 0.25 to 0.75 mol/mol of double

bond. The oxirane value conversions were given in Fig. 5.

It was found that, not only the epoxidation rate increased as

the concentration of hydrogen peroxide in the system but

also at a high mole ratio of hydrogen peroxide, oxirane ring

opening reaction also increased.

FT-IR Analysis of PJO, EPJO, ASPJO and Polymer

Film

FT-IR spectrum of PJO, EPJO, ASPJO and polymer film

are shown in Fig. 6 and represented as a, b, c and d

respectively. In spectrum a, the peak at 1,473.23 cm-1 is

characteristic of absorption of C=C stretching of PJO. The

peak at 1,758.30 cm-1 assign to C=O stretching and the

peak at 2,875.30 cm-1 corresponds to C–H stretching of

PJO. However, in spectrum b, a new peak was observed at

822.491 cm-1 exhibiting C–O stretching (asymmetric

stretch) bands for oxirane, thus it evident that epoxidation

of PJO had taken place. In spectrum c, the peaks at 1,649.8,

3,400.85, 1,116.58 cm-1 correspond to N–H bending, O–H

stretching and Si–OCH3 stretching respectively, thus from

the results, it is evident that epoxy ring had been opened by

APTS and ASPJO was formed. In spectrum d, the peak at

3,363.25 cm-1 corresponds to N–H stretching of the ure-

thane linkage. Thus from the above FT-IR data, it can be

concluded that polyurethane was successfully synthesized

from PJO.

1H-NMR Analysis of ASPJO

The 1H-NMR spectrum of ASPJO is shown in Fig. 7. 1H-

NMR (CDCl3): the peak at d 4.1 m is assigned to –CH–O–

(Fig. 7, h), the peak at d 3.8 t corresponds to –O–CH2–

(Fig. 7, g), the peak at 3.6 m corresponds to –Si–O–CH3–

(Fig. 7, c), the peak at d 3.2 q corresponds to –CH–O–

(Fig. 7, n), the peak at d 3 t assign to –CH2–N (Fig. 7, i),

the peak at d 2.9 t corresponds to –CH2–CO (Fig. 7, d), the

peak at d 2.6 s corresponds to –NH– (Fig. 7, a), the peak at

d 2.3 q assign to –CH–N (Fig. 7, m), the peak at d 1.6 m

assign to –CH2–C–Si– (Fig. 7, j), the peaks at d 1.1–1.5

corresponds to –CH2–CH2–CH2–CH2 (Fig. 7, e and f), the

peak at d 0.9 t corresponds to –CH3 (Fig. 7, l) and the peak

at d 0.6 t assign to –Si–CH2 (Fig. 7, k). Thus from the 1H-

Fig. 4 Effect of acetic acid concentration on relative percentage

conversion to oxirane. Conditions: temperature 60 ± 1 �C; mole

H2O2 per mole of double bond = 1.1 and H2SO4 = 2 %

Fig. 5 Effect of H2O2 concentration on relative percentage conver-

sion to oxirane. Conditions: temperature 60 ± 1 �C; mole acetic acid

per mole of double bond = 0.5 and H2SO4 = 2 %

Fig. 6 FT-IR spectrum of a PJO, b EPJO, c ASPJO and d polymer

film

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NMR data, it is concluded that the ASPJO was successfully

synthesized.

Physico-Chemical Analysis

The physico-chemical analysis of the PJO, EPJO and AS-

PJO are depicted in Table 1. The epoxidation of PJO is

evident from the decrease in the iodine value from 101 to

6.13 g of I2/100 g oil and also from the epoxy equivalent of

EPJO. The modification of epoxidized oil with APTS was

confirmed by the amine value and hydroxyl value of the

ASPJO. The amine value and hydroxyl value of ASPJO

shows that epoxy ring was opened by APTS and polyol was

formed.

Scanning Electron Microscopic (SEM) Analysis

The morphological study of the polymer film was done

with the help of scanning electron micrographs. From the

SEM micrographs it was difficult to identify the hard and

soft segments. The SEM micrographs confirmed the uni-

form phase distribution of the polymers at different hard

segment contents which are shown in Fig. 8.

Gel Content Measurement (%)

The extent of cross linking of ASPJO with different con-

centrations of NCO (NCO to OH mole ratios 0.2, 0.4, 0.6,

0.8 and 1) was measured by extraction in terms of the gel

content. The change in gel content as a function of the

cross linking of ASPJO with different concentrations of

NCO. It was found that with the increase in concentration

of NCO, the cross linking of polymer was increased, but at

lower concentration of NCO the gel content was found to

be 80 %, which showed that the silane was converted to

silanol and formed a crosslinked network, it results in the

gel content being increased. At 0.2, 0.4, 0.6, 0.8 and 1 NCO

to OH mole ratios, the gel content was 79.8, 87.7, 91.9,

92.5 and 94.9 % respectively.

In-Vitro Degradation of Polyurethane

In-vitro degradation of polyurethane (polyurethane of dif-

ferent NCO:OH mole ratios of 0.2, 0.4, 0.6, 0.8 and 1) was

carried out in a phosphate buffer solution (PBS, pH 7.4,

0.1 M), 1.0 mg proteinase K and 1.0 mg sodium azide

(NaN3, preventing bacterial development) at 37 �C. The

degradation rate was evaluated by the weight loss of the

polymers over predetermined time intervals. It was

Fig. 7 1H-NMR spectrum of

ASPJO

Table 1 Physico-chemical analysis

PJO EPJO ASPJO

Iodine value (g I2/100 g) 101 6.13 –

Epoxy equivalent (g/equiv. epoxy group) – 347.82 –

Amine value (mg KOH/g) – – 70.02

Hydroxyl value (mg KOH/g) – – 213.7

J Am Oil Chem Soc

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observed that, the polyurethane with a NCO:OH mole ratio

of 0.2:1 was degraded by 30.3 % in 20 days where as the

polyurethane with a NCO:OH mole ratio of 1:1 was

degraded by 19.6 % in 20 days. From the above result it

was observed that as the concentration of NCO increases,

the rate of polymer degradation also decreases. This is due

to the increasing concentration of NCO leading to

increasing crosslinking in the polymer. The crosslinking

was also evident by the gel content of polyurethane. The

weight of polymer decreased due to the enzymatic hydro-

lysis of ester groups of polymer [29]. In vitro degradation

of polyurethane by weight loss is shown in Fig. 9.

Contact Angle Measurement

The effects of NCO concentration on wetting characteris-

tics of polyurethane coatings were measured using a con-

tact angle measurement. As the concentration of NCO

increased, the contact angle of coatings was increased,

because cross-linking enhances the contact angle. Silanol

linkages of polymer modify the surface of coating making

it inadequately hydrophobic [20]. The polyurethane coat-

ings of different NCO to OH mole ratios of 0.2, 0.4, 0.6,

0.8 and 1, the contact angles were 79�, 81�, 82�, 84� and

85� respectively.

Gloss Measurement

The influences of NCO and silane on coatings were mea-

sured using a digital gloss meter at a reflectance angle of

60�. The increased concentration of NCO increased the

cross linking of the polymer. At lower concentrations of

NCO, the gloss of coating was 98.5, which showed the

silane was converted to silanol by moisture and a cross-

linked network had been formed [19]. The silanes act as a

surface modifier and increase the gloss of the coating. It

was observed that as the cross-linking of the polymer

increased this led to an increased gloss of the coatings. For

the polyurethane coatings of different NCO to OH mole

ratios of 0.2, 0.4, 0.6, 0.8 and 1, the gloss values were 98.5,

99.4, 103.5, 105.3 and 107.6 respectively.

Mechanical Testing of Coating

The coatings were applied onto metal panels using a bar

applicator at DFT 100 lm. The concentration of NCO was

increased from 0.2 to 1. The solvent, chemical resistance

and mechanical properties such as hardness, adhesion and

impact resistance were increased by increasing concentra-

tions of NCO, because cross-linking of the polymer was

increased. The cross-linking enhances the solvent resis-

tance and mechanical properties of the coating. At a

NCO:OH mole ratio of 1, the flexibility test of the coating

was a fail due to higher cross-linking density of polymer.

The solvent resistance, chemical resistance and mechanical

properties of coatings are shown in Table 2.

Fig. 8 Scanning electron micrographs of polymer film

Fig. 9 In-vitro degradation of polyurethane

J Am Oil Chem Soc

123


Conclusion

Bio-based polyurethane was successfully synthesized from

PJO. The optimum level oxirane conversion of PJO was

observed at 60 �C and the mole ratio of the double bond to

hydrogen peroxide to acetic acid was 1:1.1:0.5 respectively

at 2 wt% catalyst loading. The bio-based polyurethane of a

0.2 NCO:OH mole ratio was degraded by 30.3 % in

20 days. The IPDI and APTS have a significant effect on

coating performance. The IPDI and APTS formed the cross

linked structure, which imparts balanced optical and

mechanical properties of coating such as gloss, contact

angle, adhesion, hardness and impact resistance. In addi-

tion to all these, it also provides a high degree of chemical

and solvent resistance. Such a bio-based polyurethane is

useful in applications where a high degree of solvent

resistance and chemical resistance due to good adhesion

between the coating and substrate is desirable.

Acknowledgments We wish to thank UGC Green Tech. for pro-

viding financial support and also to Bayer Material Science Pvt. Ltd.

for providing isophorone diisocyanate.

References

1. Mohammad K, Eram S, Fahmina Z, Sharif A (2011) Synthesis

and characterization of ricinoleamide-based polyurethane. J Am

Oil Chem Soc 88:1989–1996

2. Deka H, Karak N (2009) Bio-based hyperbranched polyurethanes

for surface coating applications. Prog Org Coat 66:192–198

3. Okieimen FE, Pavithran C, Bakare IO (2005) Epoxidation and

hydroxylation of rubber seed oil: one-pot multi-step reactions.

Eur J Lipid Sci Technol 107:330–336

4. Liping W, Tong W (2007) Chemical modification of partially

hydrogenated vegetable oil to improve its functional properties

for candles. J Am Oil Chem Soc 84:1149–1159

5. Das G, Karak N (2009) Epoxidized Mesua ferrea l. Seed oil-

based reactive diluent for BPA epoxy resin and their green

nanocomposites. Prog Org Coat 66:59–64

6. David SB, Sathiyalekshmi K, Allen GRG (2009) Studies on ac-

rylated epoxidized triglyceride resin-co-butyl methacrylate

towards the development of biodegradable pressure sensitive

adhesives. J Mater Sci Mater Med 20:S61–S70

7. Khot SN, Lascala JJ, Can E, Morye SS, Williams GI, Palmese

GR, Kusefoglu SH, Wool RP (2001) Development and applica-

tions of triglyceride based polymers and composites. J Appl

Polym Sci 82:703–723

8. Marina G, Lucas ME, Joan CR, Gerard L, Virginia C (2009)

Vegetable oil-based thermosetting polymers. Eur J Lipid Sci

Technol 112:87–96

9. Dinda S, Patwardhan AV, Goud VV, Pradhan NC (2008) Epox-

idation of cottonseed oil by aqueous hydrogen peroxide catalysed

by liquid inorganic acids. Bio Technol 99:3737–3744

10. Goud VV, Patwardhan AV, Pradhan NC (2006) Studies on the

epoxidation of mahua oil (Madhumica indica) by hydrogen per-

oxide. Bio Technol 97:1365–1371

11. Ganghua T, Mark DS (2000) Epoxidized soybean oil-based cer-

amer coatings. J Am Oil Chem Soc 77:381–387

12. Eram S, Syed MA, Sharif A (2007) Epoxidation, hydroxylation,

acrylation and urethanation of Linum usitatissimum seed oil and

its derivatives. Eur J Lipid Sci Technol 109:134–146

13. Kayode A, Dan A, Mikael S (2010) Synthesis of reactive soybean

oils for use as a biobased thermoset resins in structural natural

fiber composites. J Appl Polym Sci 115:3137–3145

14. Pelletier H, Gandini A (2006) Preparation of acrylated and

urethanated triacylglycerols. Eur J Lipid Sci Technol 108:

411–420

15. Sharma V, Kundu PP (2006) Addition polymers from natural oils:

a review. Prog Polym Sci 31:983–1008

16. Sharma V, Kundu PP (2008) Condensation polymers from natural

oils. Prog Polym Sci 33:1199–1215

17. Guner FS, Yagci Y, Erciyes AT (2006) Polymers from triglyc-

eride oils. Prog Polym Sci 31:633–670

18. Johannes TPD, Cuperus FP, Peter K (1996) Renewable resources

in coatings technology: a review. Prog Org Coat 27:45–53

19. Semra C, Selim HK (2007) Synthesis and interfacial properties of

aminosilane derivative of acrylated epoxidized soybean oil.

J Appl Polym Sci 104:2244–2253

20. Kelnar I, Schatz M (1993) Silane cross-linking of PVC. II.

Influence of silane type and conditions on cross-linking by water.

J Appl Polym Sci 48:669–676

21. Honghai D, Liting Y, Bo L, Chengshuang W, Guang S (2009)

Synthesis and characterization of the different soy-based polyols

by ring opening of epoxidized soybean oil with methanol, 1,2-

ethanediol and 1,2-propanediol. J Am Oil Chem Soc 86:261–267

Table 2 Mechanical properties

of polymer films with various

mole ratios of NCO to OH

Mechanical properties NCO:OH molar ratio

0.2 0.4 0.6 0.8 1

Solvent resistance (toluene rub) 500 500 500 500 500

Impact resistance (F/R) Pass Pass Pass Pass Pass

Pencil hardness 4H 4H 4H 4H 4H

Scratch hardness (kg) 1.8 2 3.2 3.5 3.5

Flexibility Pass Pass Pass Pass Fail

Adhesion Excellent Excellent Excellent Excellent Excellent

Chemical resistance

Acid Pass Pass Pass Pass Pass

Alkali Pass Pass Pass Pass Pass

Water Pass Pass Pass Pass Pass

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22. Desroches M, Escouvois M, Auvergne R, Caillol S, Boutevin B

(2012) From vegetable oils to polyurethanes: synthetic routes to

polyols and main industrial products. Polym Rev 52:38–79

23. Ismail E, Motawie A, Sadek E (2011) Synthesis and character-

ization of polyurethane coatings based on soybean oil–polyester

polyols. Egypt J Petrol 20:1–8

24. Lligadas G, Ronda JC, Galia M, Cadiz V (2010) Plant oils as

platform chemicals for polyurethane synthesis: current state-of-

the-art. Biomacromolecules 11:2825–2835

25. Petrovic ZS (2008) Polyurethanes from vegetable oils. Polym

Rev 48:109–155

26. Zlatanic A, Petrovic Z, Dusek K (2002) Structure and properties

of triolein-based polyurethane networks. Biomacromolecules

3:1048–1056

27. Marangoni A, Alli I (1988) Composition and properties of seed

and pods of the tree legume Prosopis juliflora (DC). J Sci Fd

Agric 44:99–110

28. Paquot C (1979) Standard methods for the analysis of oil, fats and

derivatives, 6th edn. Pergamon, Oxford

29. Helena SA, Francisco MG, Rui LR (2003) In vitro assessment of

the enzymatic degradation of several starch based biomaterials.

Biomacromolecules 4:1703–1712

J Am Oil Chem Soc

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