Triester-amide based on thiophene and ricinoleic acid as an innovative primary plasticizer for poly(vinyl chloride)

Article abstract of DOI:10.1039/c6ra20098b

It is necessary to replace phthalate plasticizers which are used in PVC as they are found to be carcinogenic and hazardous to human health. They can be substituted with other bio based plasticizers which are non toxic. We have synthesized a triester amide of thiophene (THPRABA) with ricinoleic acid (RA) and benzoic acid (BA) reacting with a diester derivative of 2-aminothiophene (THP) which itself is procured by using Gewald multicomponent synthesis. The structure of the THPRABA was confirmed by IR, ¹H NMR, acid value, and hydroxyl value. The DOP was replaced entirely by THPRABA as a plasticizer for PVC in all samples with a varying proportion of THPRABA from 10 phr to 50 phr with a fixed heat stabilizer content as 5 phr. The incorporation of THPRABA shows a decrease in tensile and mechanical properties, glass transition temperature (T_g), crystallinity and shore hardness properties. The yellowness index shows darkening of PVC sheets with a decrease in whiteness. Hence it can replace DOP in plasticizer application successfully in some application areas of PVC.

Full text of DOI:10.1039/c6ra20098b

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Triester-amide based on Thiophene and Ricinoleic Acid as an
innovative primary plasticizer for poly(vinyl chloride)
Received 00th January 20xx,
Accepted 00th January 20xx
Sneha D. Satavalekar, Prashant B. Savvashe, Shashank T. Mhaske
DOI: 10.1039/x0xx00000x
It is necessary to replace phthalate plasticizers which are used in PVC as they are found to be carcinogenic and hazardous
to human health. They can be substituted with other bio based plasticizers which are non toxic. We have synthesized a
triester amide of thiophene (THPRABA) with Ricinoleic acid (RA) and Benzoic acid (BA) reacting with diester derivative of 2-
aminothiophene (THP) which itself is procured by using Gewald multicomponent synthesis. The structure of the THPRABA
www.rsc.org/
1
was confirmed by IR, H NMR, acid value, hydroxyl value. The DOP was replaced entirely by THPRABA as plasticizer for PVC
in all samples with varying proportion of THPRABA from 10 phr to 50 phr with fixed heat stabilizer content as 5 phr. The
g
incorporation of THPRABA show decrease in tensile, mechanical properties, glass transition temperature (T ), crystallinity
and shore hardness properties. The yellowness index shows darkening of PVC sheets with decrease in whiteness. Hence it
can replace DOP in plasticizer application successfully in some application areas of PVC.
4
are used as PVC plasticizers. The carbon long chain in
Introduction
increased the cohesive forces between adjacent polymer
Poly vinyl chloride (PVC) is widely used thermoplastic polymer
and can be used in both rigid and flexible form. In 2013 around
chains are suppressed making them process able for different
commercial application. The most famous PVC plasticizer is
dioctyl phthalate famously known as DOP. It comprises of
about 85% of total phthalate consumption all over world.
39 million tons of PVC was produced annually; having growth
rate of 5% and approximately 17 – 18 % of total polymer
production worldwide. PVC is most widely used plastic after
1
polyethylene (PE) and polypropylene (PP). Though PVC is rigid
Other phthalates which are also used are dibutyl phthalate
5
(DBP), dinonyl phthalate (DNP), etc.
and difficult to process, different additives like plasticizer,
stabilizer, impact modifier, anti oxidants, filler, lubricant,
pigments make the processing simple. The addition of
different additives makes the PVC suitable for different
commercial and healthcare materials. PVC is mainly used in
different applications like furniture, pipes, clothing material,
Phthalates are diesters of phthalic acid with alcohols
like 2-ethyl hexanol, butanol, nonanol etc. with aromatic ring
as backbone attached with long alkyl chains. Similarly
trimellitates which are triesters of trimellitic acid are also
aromatic ring containing triester group are new development
in PVC plasticizers. Apart from aromatic ring for ester
backbone some aliphatic esters are also working efficiently as
2
packaging, healthcare units, flooring, cables and wires and so
on.
6
plasticizers for PVC like adipates, citrate, etc.
Plasticizers are of two types; primary and secondary.
Primary plasticizers are more compatible with polar PVC chains
and can be used in sufficiently high quantity. On the other
hand secondary plasticizers are less compatible with PVC. They
are used as supplementary for primary plasticizer for PVC to
improve flexibility and softness of PVC and to decrease the
Due to revelation of toxic nature of phthalate based
plasticizers in PVC it has become essential to replace it with bio
based or non hazardous plasticizers. The phthalates were
found to be apparent carcinogens and reproductive,
7
-8
developmental toxicants in humans especially in babies.
3
Hence European Union had banned the use of phthalate
plasticizers in children toys. But in country like India it is still
widely used as plasticizer for PVC due to its cheap cost and lack
of availability of alternate eco friendly plasticizer.
production cost. Plasticizers are added to PVC in 10 to 60 phr.
The esters of phthalic acid, adipic acid, trimellitic acid of
aliphatic or some branch chain alcohols and some epoxidised
plasticizer separates the two PVC chains from each other and
thus imparts flexibility. As distance between two chains is oils
From last few years researchers took interest in
exploring new plasticizers for PVC devoid of phthalate esters
to decrease toxicity. The chemicals which played vital role in
this development were vegetable oils and their derivatives.
Epoxidised soya bean oil (ESBO) has become commercially
used oil based plasticizer for PVC and is produced
approximately 20000 tons worldwide. Recently Calo et al. had
Department of Polymer and Surface Engineering, Institute of Chemical Technology,
Matunga, Mumbai 400019, Maharashtra, India E - mail:
st.mhaske@ictmumbai.edu.in
Centre of Green Technology, Institute of Chemical Technology, Matunga, Mumbai –
4
00019, Maharashtra, India
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synthesized cardanol based plasticizer Cardanol acetate (CA) different chemical reactions like synthesis of polyurethanes
by esterification and used as secondary plasticizer with DOP in and polyesters.
9
partial replacement producing soft PVC. In one such attempt
We made an attempt to prepare thiophene amide of
Mehta et al had synthesized benzyl ester of dehydrated castor ricinoleic acid as primary plasticizer for PVC. It is prepared in
oil fatty acid and used as secondary plasticizer along with DOP three a step of which first is synthesis of diester amine
and epoxidised soya bean oil (ESBO). They had successfully thiophene (THP) by multicomponent Gewald reaction. In the
1
0
replaced DOP up to 65% weight with this bio based system.
Nihul et al had synthesized epoxidised rice bran oil (ERBO) with without using catalyst followed by treating it with benzoic acid
2% oxirane content by action of in situ peroxy acid and (BA) at higher temperature in the presence of catalyst i.e.
became successful in replacing 60% of DOP making it as concentrated sulphuric acid. Synthesized final product was
second step RA is treated thiophene procured in first step
8
1
1
secondary plasticizer.
Recently Baltacioğlu et al had used in different proportions in PVC as primary plasticizer and
synthesized zinc stearate and along with epoxidised soya bean thermal, mechanical, rheological, exudation and crystalline
oil (ESBO) used as secondary plasticizer with DOP in PVC. They properties were determined of the prepared sheets.
1
2
were able to use it in 5 phr along with DOP.
Wide research is being carried on for the development of
vegetable oil based plasticizer either by esterification or amide
formation. Savvashe et al. had developed a greener plasticizer
with the help of Ricinoleic acid (RA) along with benzoic acid
and dibutyl amine. They had prepared an ester amide
plasticizer of RA and successfully utilized it as a primary
Experimental
Materials and Methods
The chemicals sulphur (Thomas Baker, India), ethyl
acetoacetate, ethyl cyanoacetate, Benzoic Acid (BA) and
morpholine (LR, S. D. Fine Chem., Mumbai, India) were used as
it is without further purification. The solvent ethanol (Sterling
Chemicals, Pune, India) was used as it is without further
purification. Solvents iso propyl alcohol and chloroform were
provided by local supplier and were used after vaccum
distillation. Ricinoleic Acid (RA) was obtained by Jayant Agro,
Mumbai, India. Poly vinyl chloride (PVC, Grade: K57,
1
3
plasticizer for PVC with total replacement of DOP. Waskitoaji
et al. had synthesized ester compounds of palm oil fatty acid
which mainly contains oleic acid as main constituent with
various alcohols like iso-butanol, 1,4-butandiol and 2-ethyl
hexyl alcohol using concentrated sulphuric acid as a catalyst.
Out of these products they had found out isobutyl oleate as
most suitable plasticizer for PVC which can replace up to 80%
2
1
4
suspension resin, bulk density: 0.53g/cm , particle size:
of primary plasticizer.
2
00mesh, inherent viscosity: 0.7 dL/g) was provided by Vansh
Multicomponent reactions are unique as single
product can be derived selectively by means of proper
conditioning. One such popular reaction is Gewald synthesis of
substituted 2-amino thiophene first presented by Karl
Polyvinyl India Ltd., Mumbai, India. Lead based one packed
stabilizer was procured by Ala Chemicals, Mumbai, India.
Synthesis of triester – amide thiophene (THPRABA) plasticizer
1
5
Gewald. The product formed in that reaction was a
substituted diester amine thiophene which is used mostly in
medical field as precursor for production of different
medicines. The substituted thiophene formed can be further
modified for different commercial uses in medicine as CNS
The synthesis of triester amide thiophene (THPRABA)
plasticizer is a three step process. The first step involves the
synthesis of diester amine thiophene (THP) as mentioned
earlier by Gewald using multicomponent synthesis. The second
step is carried out by reacting ricinoleic acid with equimolar
quantity of synthesized substituted thiophene (THP) at high
temperature without addition of any catalyst to form THPRA.
The third step is formation of ester of benzoic acid at high
temperature in presence of concentrated sulphuric acid to
produce benzoate ester of THPRA i.e. THPRABA. The first step
of the reaction was synthesis of diester amine thiophene
synthesis by multi component reaction suggested by
1
6
17
antidepressant,
anticancer agents, antiallergic, analgesic,
anti-inflammatory and ocular hypotensive activities. They can
1
also be used as azo dyes in dye chemistry, conductivity-based
8
1
9
sensors, etc.
The use of substitute 2-amino thiophenes can be
converted either into diesters, amide or used as it is for
examining its plasticizer nature. The procured substituted
thiophene can work as heteroaromatic backbone for ester
groups which can either work as primary plasticizer or can be
process with other primary plasticizers as secondary
plasticizer. The prepared PVC sheets can be analyzed for its
mechanical, rheological, thermal and other properties.
1
5,22-23
Gewald.
The reaction was carried out in three necked
round bottom flask attached with thermocouple arrangement,
condenser and addition funnel, water bath for heating and
magnetic stirrer. The equimolar mixture of sulphur, ethyl aceto
0
acetate and ethyl cyano acetate were charged at 35
C
Ricinoleic acid is a major constituent of castor oil
followed by drop wise addition of morpholine as a catalyst.
0
This reaction was then stirred at 1000 rpm for 24h at 55 C for
which is obtained from the endosperm of castor- bean (Ricinus
communis) in the triacylglycerol form i.e. castor oil. As castor
oil is widely produced in India the cost of it is 0.41 $ per
successful completion of reaction. The product synthesized
was filtered and washed thoroughly with 3 X 30 mL of ethanol,
dried and recrystallized with ethanol to procured purified
product which was dried and used for further reactions. The
second step of the reaction was carried out in a four necked
20
pound. RA is cis isomer having both carboxyl and hydroxyl
21
group along with a double bond. The presence of two active
reacting group along with double bond makes RA special for
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reactor equipped with thermocouple arrangement, Dean – uniform reaction. After the completion of reaction the flask
Stark apparatus, nitrogen gas purging system and mechanical were cooled to room temperature followed by addition of 10
stirrer. The obtained THP is reacted in equimolar quantity i.e. mL of water through air condenser in both the flasks. For the
1
:1 mole with RA in the absence of any catalyst. The reactants hydrolysis of excess acetic anhydride both the flasks were
0
0
were heated gradually from 170 C to 180 C at 500 rpm under heated again on oil bath for 15 minutes. Flasks were then
nitrogen gas as purger. The progress of the reaction was cooled to room temperature and 25 mL of neutralized alcohol
monitored by calculating acid value of the reactants at interval was added to it (partially through condenser which was
of 30 minutes. The reaction was carried out till acid value of removed afterwards). The mixtures in the flasks were then
the reactants was decreased below 15mg KOH/ g of sample swirled meticulously and 1 mL of phenolphthalein indicator
and that required almost 18 hours. The next step was was added. Both the mixtures were then titrated with 0.5 N
performed without further purification of the product standardized alcoholic KOH till faint pink colour was obtained
obtained in earlier step. The obtained product was heated as end point which remained persistent for 30 seconds or
0
0
gradually from 170 C to 180 C at 500 rpm under nitrogen gas more. The calculation of hydroxyl value is determined by
with equimolar quantity of benzoic acid using 98% conc. following formula:
sulphuric acid (0.1% w/w of benzoic acid) as catalyst. By Hydroxyl Value = [56.1 X normality of alc. KOH X (mL KOH
calculating acid value of the reactants at interval of 30 minutes Blank - mL KOH sample)] / [weight of sample] - acid value.
progress of the reaction was monitored. Reaction was Preparation of PVC sheets: For the preparation of PVC sheets
continued till acid value was decreased below 15mg KOH/ g of it is necessary to obtain uniform mixture of required quantity
sample which required 18 hours. The final product produced of PVC, novel THPRABA and one pack stabilizer. The required
was used as it is without further purification as PVC plasticizer. compositions were dry blended in a high speed mixer for 5
Reaction scheme for the synthesis of THPRABA is given in minutes. Table 1 provides the information of compositions
Figure 1.
Yield of diester amide thiophene derivative of ricinoleic on a two - roll mill at 180 C for half an hour to convert all the
benzoate (THPRABA) is given by following formula: mixture in to uniform molten mass. Materials procured from
Yield of plasticizer = (Weight of plasticizer synthesized)/ two – roll mill were predried in oven for 6 to 8 hours to get rid
Theoretical yield of plasticizer)
arranged and there nomenclature. Melt bending was carried
0
(
Step 1
Analysis and Characterization
O
O
O
O
O
0
S
NH2
5
5 C, 24 h
+
NC
+
S
8
Acid Value: Acid value is number of milligrams of potassium
hydroxide required to replace free carboxyl acid group present
in one gram of sample and is determined according to ASTM
O
O
Morpholine
O
H C
3
O
1
2
3
4
Ethyl Aceto Acetate
Ethyl Cyano Acetate Sulphur
2-Amino-4-methyl-3,5-bisethyl
carboxy thiophene (THP)
2
4
D1980. In a 125 mL Erlenmeyer flask approximately 1 g of
THPRABA plasticizer was taken and dissolved in 50 mL of
benzene alcohol mixture in 1:1 ratio. The flask was heated on
water bath for somewhat 5 – 10 minutes for dissolution of
THPRABA. To this solution 5 – 6 drops of phenolphthalein
indicator were added and shaken well. The solution was
titrated with 0.5 N alcoholic KOH to determine acid value. The
end point was colourless to light pink where pink colour
remains persistent for approximately 30 seconds. The
calculation of acid value was determined by following formula:
Acid Value = (Volume of alc. KOH X normality of alc. KOH X
Step 2
O
0
0
O
170 C - 180 C
8 h, N2 atm
- H2O
S
NH2
OH
1
O
H
O
+
3
C
OH
5
O
4
THP
O
Ricinoleic Acid (RA)
O
S
N
H
O
3
O
CH
OH
O
6
THPRA
Step 3
56.1) / (weight of sample)
O
O
OH
Hydroxyl Value: The ASTM standard D1957 describes the
2
procedure and determination of hydroxyl value of sample.
O
O
S
0
0
1
70 C - 180 C
5
N
H
18 h, N2 atm
+
O
CH
3
Hydroxyl number is number of replaceable hydroxyl group by
potassium hydroxide in one gram of sample. In a 250 mL
Erlenmeyer flask 5 grams of accurately weighed sample was
dissolved in 20 mL of acetic anhydride: pyridine (1:4 volume
ratio) reagent attached with air condenser. Whereas another
Erlenmeyer flask was without sample and treated as blank
equipped with air condenser with prior addition of 20 mL of
acetic anhydride: pyridine (1:4 volume ratio) reagent. Both the
flasks were then immersed in oil bath up to liquid level and
conc. H SO4
H2O
2
OH
O
-
6
7
THPRA
Benzoic Acid (BA)
O
O
S
N
H
O
O
CH3
O
O
O
8
0
0
temperature of bath was maintained at 95 C to 100 C. To
THPRABA
ensure complete dissolution of sample the flasks were shaken Figure 1: Reaction scheme for the synthesis of Triester amide thiophene THPRABA)
vigorously and reaction was carried out for 1 hour to assure from substituted 2-Amino thiophene, Ricinoleic Acid and Benzoic Acid
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Table 1: Prepared PVC/THPRABA compositions and their nomenclature
X – Ray Diffraction Analysis: For the determination of effect of
added diester thiophene amide of Ricinoleic acid benzoate
One pack
(THPRABA) on the crystallinity of the prepared PVC sheets X-
Sample Name
PVC
g)
Stabilizer
phr
THPRABA
ray diffraction was carried out. The X-ray diffraction analysis
was accomplished on Rigaku Miniflex (Japan) which was
operating on40 kV and 30 mA having a copper X-ray tube (Cu,
(
g
phr
g
PVCVIRGIN
THPRABA10
THPRABA20
THPRABA30
THPRABA40
THPRABA50
200
200
200
200
200
200
5
5
5
5
5
5
10
0
0
0
Kα), wavelength K= 1.5418A ). Scan speed was maintained at
10
10
10
10
10
10
20
30
40
50
20
40
60
80
0
-1
min . The scan range for diffraction angle, 2θ was from 2 to
3
6
0
0 while data was collected continuously. Data analysis was
executed on Jade 6.0 software which was supplied by
manufacturer.
Percent crystallinity was calculated according to the equation
stated below:
100
% Crystallinity = {(total area of crystalline peaks) / (total area of
all peaks)} X 100.
Exudation Test: The prepared sheets of THPRABA added PVC
along with DOP added PVC sheet were kept to check the
exudation in between two pieces of tissue paper. The joint PVC
sample sheet along with tissue paper was kept at room
temperature for 1 week. After completion of one week tissue
paper was separated and weighed for the determination of
extent of thiophene exudation.
of any absorbed or adsorbed moisture.
Compression Molding: Sample sheets for testing were
prepared with the help of upward stroke compression molding
machine of molten mass. The upper and lower platen
0
0
temperatures were maintained at 180 C and 185 C
respectively along with applied pressure of 20 MPa. During the
compression stage heat and pressure were applied for 15 to 20
minutes. Additional 40 – 45 minutes were required for cooling
of the prepared sheets to room temperature. The dimensions
of the sheets procured were 20 cm X 20 cm X 2 mm which
were cut to get samples of required measurement for further
testing.
Colorimetric Analysis: According to ASTM standard D1925
yellowness – C of the PVC samples was determined. CIE L*, a*,
b* and ΔE values for the THPRABA plasticizer compositions
were determined using Colour Spectrophotometer (Colour Eye
7
000, Optiview Light Quality Control 1.9, Gretag Macbeth,
0
Germany). Observer was placed at 10 . Illuminant used was
D65.
Fourier Transform –Infrared Spectroscopy (FT-IR): The
instrument Bruker, India was utilized to record the FT-IR
spectrum of the synthesized THPRABA plasticizer. The 1-2%
solution of THPRABA was prepared in chloroform as solvent.
The background spectrum was run prior to analysis of the
chloroform and used its peak as baseline for automatic
subtraction from sample peaks. The prepared PVC sheets with
varying concentration of plasticizer along with virgin PVC sheet
were characterized on Bruker ATR. The samples were scanned
Differential Scanning Calorimetry: By using Differential
Scanning Calorimetry (Q 100 DSC, TA instruments Ltd., India)
the deviation in glass transition temperature of THPRABA
0
included PVC sheets were determined. Scanning rate of 20 C
-1
min was maintained for the heating cycle and nitrogen gas
-1
purge rate was maintained at 50 mL min . Samples were
o
scanned from range -40 C to 120 C.
o
Thermo Gravimetric Analysis: The Thermo Gravimetric
Analysis was carried on Pyris 1 TGA, Perkin Elmer, India to
study degradation and percent weight loss of synthesized
THPRABA plasticizer along with prepared PVC sheets varying in
plasticizer concentration. Scanning rate was maintained at
-
1
-1
in the range of 600 – 4000 cm with a resolution of 4 cm .
1
1
1
H Nuclear Magnetic Resonance ( H NMR): The H NMR of
synthesized THPRABA plasticizer was carried on Mercury Plus
00 MHz Spectrometer, Varian, USA. The sample was dissolved
3
0
-1
o
o
2
0 C min for heating range of 50 C to 650 C. The nitrogen
in DMSO-d6 solvent and NMR was run from 0 to 12.5 ppm
scale.
-1
purge rate was sustained at 35 mL min .
Rheological Analysis: For the determination of viscosity
Mechanical Properties: With the help of Universal Testing
Machine (LR-50K, Lloyds Instrument, UK) tensile properties
behaviour of dioctyl phthalate (DOP) and THPRABA
a
Brookfield viscometer (Rheotec) with spindle type: L2 having
rotation speed 150 rpm was utilized. The THPRABA added PVC
(
tensile strength, tensile modulus and percentage elongation
at break) and flexural properties like flexural strength were
measured respectively in accordance with ASTM standard
0
samples were analyzed at temperature ~200 C along with DOP
2
6, 27
and THPRABA; both were measured at room temperature
0
D638 and D790 at ambient condition.
The crosshead speed
-1
~
30 C to understand detailed flow behaviour of materials.
For the verification of rheological behaviour THPRABA
was preserved constant at 50 mm min with initial partition in
grip was 50 mm and load cell of 100 N. For flexural analysis the
-1
and to compare it with that of DOP, Rheometer (MCR 101,
Anton Paar, Austria) was used. Cone and plate (spindle name:
0
CP35-2-SN20784, diameter: 35 mm, cone angle: 2 ) were
speed was maintained at 2.8 mm min for sample length of 80
mm.
Shore D Hardness: Shore D hardness of all the prepared virgin
separated by a distance of 0.147 mm during the rheological
study. Rheoplus/32V3.40 software was used for the data
analysis and was provided by the supplier for operating. During
and THPRABA added PVC sheets were calculated in accordance
with ASTM D-2240. Sheet dimension were 2 cm X 2 cm X 0.2
cm and samples were analyzed at 10 to 15 different locations.
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the rheological study the temperature was maintained THP, one ester group formed due to benzoate ester including
0
constant at 200 C. The test was carried out in the experimental newly formed amide carbonyl (
̶ CON< ) bond. The spectrum
time of 200 s. Twenty-five viscosity/shear rate data points does not show four >CO stretching frequencies but collectively
-1
were obtained, at 6 points/decade. The shear rate during the shows a broad sharp stretch at 1699.10 cm . The band
-1
-1
-1
-1
shearing of the samples was maintained from 0.1 s to 500 s . observed at 1550.66 cm and 1505.42 cm are of medium
intensity and indicates C C stretching of benzene ring. The
peak at 1449.77 cm belongs to C N stretching of primary
amide. The band observed at 1373.95 cm indicates the
symmetric bending vibration of RA. The peak at 1229.75 cm
indicates stretching vibration of C C linkage. The band at
H bending vibration of mono-
̶
-1
̶
-1
Results and Discussion
̶
CH
3
-
1
The plasticizer plays a very important role in difficult to
process thermoplastic polymers by improving their flexibility,
tensile strength, process ability and reducing glass transition
̶
O ̶
-
1
7
08.92 cm implies the C ̶
substituted benzene group. Hence FT-IR analysis proves the
synthesis of THPRABA.
g
temperature (T ), melt viscosity, etc. In present study we have
prepared diester amide of thiophene with the help of ricinoleic
acid and benzoic acid and used it for various characterizations
like acid value, hydroxyl value, FTIR, Brookfield viscosity,
rheology. The PVC sheets prepared with THPRABA were
characterized for FTIR, exudation, mechanical, thermal,
rheological, crystallinity, chemical resistance, etc.
1
H NMR Analysis:
1
The H NMR spectrum for synthesized THPRABA plasticizer is
shown in figure 3. Figure illustrates all the chemical shifts
corresponding to protons in correlation with structure of
THPRABA plasticizer. The chemical shift values at 0.68 ppm
and 0.84 ppm are due to long aliphatic chain representing C-17
and C-16 resp. present in ricinoleic acid as shown in figure. The
Characterisation of THPRABA Plasticizer:
multiplet at 1.27 ppm is due to aliphatic ̶ CH groups of carbon
2
The acid value and hydroxyl value of the synthesized THPRABA
was found to be 10.8 and 11.2 mg KOH/ g of sample.
numbering 3, 4, 5, 14 and 15 as displayed in figure. Methyl
protons of aromatic thiophene ring show singlet with chemical
shift of 2.39 ppm where as protons of benzene ring appeared
downfield having multiplet at 7.56 ppm. The ethyl ester
protons of thiophene ring attached to C-19 and C-22 display
multiplet at 4.23 ppm whereas protons belonging to carbon
number 20, 23 represent peak at 1.51 ppm. The protons
attached to carbon numbering 11 which is a benzoate ester
shows peak at 5.34 ppm. The protons adjacent to double bond
of RA i.e. protons belonging to C-7 and C-10 exhibit chemical
shift value 1.95. The protons corresponding to double bond of
RA i.e. protons attached to C-8 and C-9 show down field shift
at 6.81. The formation of amide is confirmed by chemical shift
value at 7.96 ppm. There is no presence of peak between 10 to
Plasticizer Demand Value:
The plasticizer absorption value for prepared triester amide
plasticizer and DOP were found to be 45.2g and 52.8g resp. per
100g of PVC.
FT-IR Analysis:
The figure 2 provides the FT-IR spectrum of THPRABA
plasticizer. The FT-IR analysis of synthesized THPRABA shows a
-1
broad band of low intensity around 3302.87cm which jointly
predicts the presence of unreacted hydroxyl group ( OH) and
amine ( NH ) group present in ricinoleic acid and THP
respectively. It also confirms the primary amide bond formed
̶
̶
2
-1
-1
1
2 ppm which indicates no presence of carboxylic proton in
plasticizer molecule. This indicates that complete conversion
groups in RA respectively. The spectrum shows a broad band of ricinoleic acid into its amide-benzoate ester.
of THP with RA. The bands at 2923.46 cm and 2855.91 cm
represent the asymmetric and symmetric stretching of CH
̶
2
-1
around 1699.10 cm which belongs to >CO stretching
collectively implies the occurrence of two ester group from
1
Figure 3: H NMR spectrum for synthesized THPRABA plasticizer
Figure 2: FT-IR spectrum obtained for THPRABA plasticizer
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Journal Name
ARTICLE
Thermo Gravimetric Analysis:
and 30 phr PVC sheet but for remaining samples do not show
much variation and remains approximately constant. However
there is no drastic change in characteristic PVC bands at
The TGA of synthesized THPRABA plasticizer is displayed in
figure 4. The figure shows single step degradation of plasticizer
which clearly suggests that plasticizer gets degraded
-1
-1
9
59.12 cm and 688.37 cm due to addition of plasticizer.
o
completely in the specified temperature range of 50 C to
o
50 C. The onset and end set temperatures are 311.83 C and
o
6
o
13.83 C resp. The percent loss is found to be 96.109% while
4
ash content is 3.19%. The entire plasticizer gets degraded with
elimination of CO and CO from ester and amide group resp.
2
and polyenes from THPRABA.
Characterisation of PVC sheets:
FT-IR Analysis:
The spectrum shows characteristic band for PVC at 2915.43
-1
-1
-1
cm , 959.12 cm and 688.37 cm . The figure 5 shows overlay
spectrum of PVC plasticized with THPRABA plasticizer with
concentration varying from 10 phr to 50 phr along with virgin
-1
PVC. The THPRABA10 shows band at 1660.48 cm which
corresponds to C=O stretching of plasticizer molecule and it
increased as concentration of plasticizer increases. The peak
-1
value at 1660.48 cm corresponding to THPRABA10 goes on
-1
increasing to 1671.28 cm which continue to increase up to
-
1
-1
673.78 cm then slightly decreases to 1667.33 cm and again
1
-1
increases to some extent to 1669.25 cm respectively for
increasing concentration of plasticizer from 20 phr to 50 phr in
-
PVC. The ester C ̶ O band increases gradually from 1213.26 cm
1
-1
to 1232.12 cm for 10 phr to 30 phr plasticizer concentration
-1
which decreased to 1223.00 cm for increasing concentration
of plasticizer for 40 phr and remains nearly constant at
-
1
1
225.60 cm for 50 phr of THPRABA. The amide N
̶ H
stretching frequency for THPRABA10 is found to be 3394.33
-1
-1
cm which increases slightly to 3398.34 cm for THPRABA20
-1
and then decreases to 3381.14 cm for 30 phr plasticizer
concentration which increases again for THPRABA40 to
-
1
3
397.35 cm and then almost remains constant to attain value
-1
of 3398.09 cm for THPRABA50. The C
also gradually increased from 1424.76 cm to 1429.99 cm for
0 phr to 50 phr increase in THPRABA concentration on PVC.
The aliphatic C H stretching frequencies have found to be
̶ N stretching frequency
-1
-1
1
̶
-1
-1
increased slightly to 2918.03 cm , 2917.35 cm resp. for 20
Figure 5: FT-IR spectra obtained for PVC sheets: virgin and plasticized with
varying concentration of THPRABA plasticizer
Figure 4: TGA analysis of THPRABA plasticizer
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Table 2: Effect of THPRABA plasticizer addition on the Wave number of specific peaks of PVC sheets: virgin and plasticized with varying concentration of THPRABA plasticizer
FT-IR Peaks
Sample
Name
Amide
Aliphatic
Ester & Amide
C = O
Amide
Ester
Distinctive
PVC
PVC peaks
Cl
N
̶
H
C
̶
H
C
̶
N
C ̶ O
C
̶
Stretching
-
stretching
2915.43
2915.31
2918.03
2917.35
2915.40
stretching
Stretching
-
stretching
-
peaks
PVCVIRGIN
THPRABA10
THPRABA20
THPRABA30
THPRABA40
-
959.12
960.44
961.23
964.44
962.44
688.37
686.80
689.09
691.62
691.17
3394.33
3398.34
3381.14
3397.35
1660.48
1671.28
1673.78
1667.33
1424.76
1428.84
1425.43
1430.33
1213.26
1229.23
1232.12
1223.00
THPRABA50
3398.09
2915.78
1669.25
1429.99
1225.60
963.65
692.65
-
1
There is slight change in characteristic PVC peak of 959.12 cm
value of 19.2MPa for 50 phr sheet. The PVC sheet containing
to 964.44 cm , 962.44 cm and 963.65 cm resp. for 30 phr, 10 phr plasticizer exhibits only 2.52 % elongation which
0 phr and 50 phr plasticizer addition. The characteristic PVC drastically increases up to 143.92 % for 50 phr sheet making it
-1
- 1
-1
4
-1
band at 688.37 cm increases slightly for each increasing easier to process. The values for tensile modulus, tensile
-1
plasticizer addition to finally attain value of 692.65 cm for strength, percent elongation and flexural strength for PVC
THPRABA50 sheet.
sheets with varying concentration from 10 phr to 50 phr are
given in table 3. The combine graph showing effect on tensile
modulus, tensile strength, percent elongation and flexural
Mechanical Properties:
The difference in electro negativity value of chlorine and strength due to addition of plasticizer in varying concentration
hydrogen can impart electrostatic attraction between the on PVC is displayed in figure 6. The tensile modulus, tensile
same when present on adjacent molecules. Hence adjacent strength, and flexural strength display overall reduction of
PVC chains show electrostatic attraction between chlorine 71.618 %, 65.917 % and 65.606 % reduction for THPRABA50
from one PVC chain to hydrogen of other PVC chain due to sheet in comparison with virgin PVC sheet.
dipole – dipole interaction. This makes PVC hard and rigid
Shore D Hardness:
material to process. The addition of plasticizers reduces this
dipole – dipole interaction by placing itself in between two The virgin PVC has Shore D Hardness value 94. After the
PVC molecules. The plasticizer acts as a spacer reducing tensile addition of plasticizer the Shore D Hardness value decreases
strength, tensile modulus, flexural strength and simultaneously gradually indicating increased plasticity and reduction in
it enhances the elongation of polymer chain which expands its rigidity of plasticized PVC. The Shore D value of THPRABA 10 is
application area.
found to be 87 which decreased up to 64 for THPRABA 50. The
The values for tensile modulus, tensile strength, percent decrease in Shore D value for THPRABA 50 is 32%. The
percent elongation and flexural strength for PVC were found to Shore D hardness values for THPRABA10-50 are 87, 85, 79, 69
be 1978.04 MPa, 56.54 MPa, 1.3% and 116.07 MPa. After the and 64 resp. The presence of different polar groups like
addition of THPRABA plasticizer the tensile modulus decreases thiophene ring, benzene ring, ester C=O linkage, amide N
gradually from 1771.59 MPa for 10 phr sample sheet to 561.4 group etc. in plasticizer molecule helps it to disperse uniformly
MPa for 50 phr PVC sheet. Tensile strength for PVC shows into PVC matrix. These polar groups interact with C Cl group of
slight decrease from 45.92 MPa for 10 phr PVC sheet to 44.72 PVC while acting as a spacer and thus number of PVC
MPa for 20 phr sheet and then decreases gradually to attain molecules occupying per unit area decreases. This leads to
̶ H
̶
Table 3: Summarization of Tensile Modulus (MPa), Tensile Strength (MPa), Percent Elongation at Break and Flexural Strength (MPa) for PVC sheets: virgin and plasticized with
varying concentration of THPRABA
Tensile Modulus
MPa)
Tensile Strength
(MPa)
Flexural Strength
(MPa)
Sample Name
% elongation
(
PVC VIRGIN
THPRABA10
THPRABA20
THPRABA30
THPRABA40
THPRABA50
1978.03 ± 4.23%
2190.23 ± 1.18%
1426.91 ± 3.63%
1091.61 ± 2.19%
851.76 ± 4.11%
561.4 ± 1.64%
56.54 ± 1.33%
45.92 ± 0.78%
44.72 ± 1.91%
42.60 ± 0.59%
27.48 ± 2.65%
19.27 ± 2.02%
1.3 ± .98%
2.52 ± 2.15%
5.40 ±.73%
116.07 ± 1.43%
149.03 ±4.65%
148.49 ±1.01%
101.24 ± 4.68%
65.07 ± 1.05%
39.92 ± 2.56%
28.68 ± 0.37%
89.2 ± 1.17%
143.92 ± 4.89%
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Figure 8: X-ray Diffractograms obtained for PVC sheets: virgin and plasticized with
Figure 6: Summarization of Tensile Modulus (MPa), Tensile Strength (MPa) and
Elongation at Break (%) for PVC sheets: virgin and plasticized with varying
concentration of THPRABA plasticizer
varying concentration of THPRABA
Exudation Test:
The exudation test results show that exudation of 0.1 to 0.5 %
for PVC/THPRABA sheets as given in figure 9 and are
comparable with that of PVC/DOP sheets which shows similar
exudation results. There is no weight loss in THPRABA
plasticized PVC sheets while carrying out different analysis.
This can be attributed to better compatibility of THPRABA
plasticizer with PVC chains.
decrease in packing density of PVC imparting flexibility to PVC.
The graph displaying relation of Shore D hardness with that of
PVC sheets with increased concentration of plasticizer is
shown in figure 7.
X-ray Diffraction:
The X-ray diffractograms were obtained for PVC sheets added
with THPRABA plasticizer along with virgin PVC sheet and are
summarized in figure 8. As can be seen in the figure X ray
diffractogram does not show appreciable changes in peaks.
However the percent crystallinity of the sheets was decreased
simultaneously from PVCVIRGIN to plasticizer added PVC
sheets. The PVCVIRGIN shows crystallinity of 9.2% which
gradually decreases to 8.94%, 7.19%, 6.72%, 5.85% and 5.13%
resp. for THPRABA10-50 sheets. Thus it shows 44% decrease in
crystallinity for THPRABA50 as compared to PVCVIRGIN sheet
and is a substantial decrease for amount of plasticizer added.
The decrease in percent crystallinity is in accordance with
mechanical and thermal analysis. The plasticizer molecule
places itself in between PVC matrix in such a way that the
polar attraction exhibited by chlorine and hydrogen atoms of
adjacent chain gets decreased and ultimately intermolecular
forces of attraction between PVC sheets reduced. This in turn
ensures decrease in crystallinity due to changes in molecular
alignment.
Colorimetric Analysis:
The values for L*, a*, b*, ∆E*, yellowness index and whiteness
index for PVC sheets which are virgin and plasticized with
THPRABA are summarized in table no. 4. RA is dark yellow
liquid which on reacting with substituted thiophene (THP) and
BA becomes even more dark red. Hence slight addition of
plasticizer in 10 phr also imparts PVC a dark colour which on
further addition of plasticizer gets intensified. As given in table
the values for L* decreases gradually from 37.123 for virgin
PVC to 31.314 and 27.383 resp. for 10 and 20 phr sheet which
there after shows slight reduction and attains value of 26.514
for 50 phr sheet. ∆E* values show increase for 10 to 30 phr
sheet from 6.438 to 10.242 which afterwards increases slightly
for 40 and 50 phr sheet by attaining values of 10.634 and
1
0.721 resp. The reflectance of PVC sheet is found to be
always higher than plasticized PVC sheet with THPRABA from
Figure 7: Shore
D Hardness of PVC sheets: virgin and plasticized with varying
Figure 9: Exudation test results obtained for PVC sheets plasticized with DOP and
concentration of THPRABA plasticizer
THPRABA plasticizer
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Table 4: Colorimetric Analysis for prepared PVC/ THPRABA sheets
NAME
L*
a*
b*
∆E*
Yellowness Index
Whiteness Index
PVC VIRGIN
THPRTABA10
THPRTABA20
THPRTABA30
37.123
31.314
27.383
26.958
-0.169
-0.188
0.116
0.189
3.49
6.185
2.578
2.221
-
13.371
26.262
12.958
11.532
-24.112
-60.397
-25.218
-21.398
6.438
9.781
10.242
THPRTABA40
THPRTABA50
26.573
26.514
0.059
0.158
2.105
1.877
10.634
10.721
10.807
9.916
-20.388
-17.685
wavelength range 400 μm to 750 μm. The reflectance of all the PVC however show dramatic reduction in T
g
with addition of
8.79 C which shows slight
g
for 20 to 50 phr THPRABA sheets. The
o
plasticized PVC sheets almost remain constant up to 400 μm to 10 phr THPRABA and has T
10 μm after which there is a gradual increase in reflectance reduction in T
with increase in plasticizer concentration up to 750 μm. The THPRABA50 sheet has T
yellowness index for virgin PVC was found to be 13.371 which reduction in T as compare to virgin PVC. The curves also show
g
6
o
g
value 5.59 C which is a drastic
g
drastically increase to 26.262 for 10 phr sheet indicating more reduction in melting point for PVC due to plasticizer effect. The
o
yellowness in sheet. It is important to note that the point melting point for PVC virgin is 103.24 C which decreased up to
o
indicating colour of 10 phr PVC sheet is found to be on positive 77.30 C for THPRABA10 sheet. After that it gives slight gradual
o
o
o
o
Y axis indicating more yellowness of sheet. However for rest all reduction of 71.28 C, 69.56 C, 70.56 C and 69.57 C resp. for
the samples of PVC the point is found to be on negative Y axis 20 to 50 phr sheets. Thus it is clear from the graph that
indicating reddishness of sample sheet which slightly increases plasticizer molecule adjusted itself between two PVC sheets in
with every addition of plasticizer confirming decrease in such a way that the dipole attraction exhibited by adjacent
yellowness index values for 20 to 50 phr sheets resp. The sheets due to C
̶ Cl interaction is decreased.
whiteness index of virgin PVC sheet is found to be -24.112 The synthesized THPRABA decreases the glass
which drastically decrease to -60.397 on little addition of transition temperature of PVC sheet. It is in accordance with
THPRABA plasticizer in 10 phr concentration. It increases to - tensile and X-ray diffraction results which suggest
17.685 for 50 phr plasticizer concentration in PVC sheet. It is plasticization effect shown by product. The polar group
very much clear that on addition of THPRABA plasticizer in to present in plasticizer like C=O, N ̶ H along with aromatic ring of
PVC matrix makes PVC sheets redder and bluer resulting in thiophene and benzene places them self in between two PVC
decrease in yellowness index and dark redder, almost blackish sheets placing them further apart. Due to this reduction in
in appearance.
glass transition and melting point is observed. Simultaneously
it decreases the number of per unit area of PVC molecules.
Decrease in glass transition temperature and melting point
Differential Scanning Calorimetry:
The glass transition curves obtained for virgin PVC along with helps by making PVC easier to process which is otherwise
plasticized PVC are summarized in figure 10. The T for virgin difficult to process without plasticizer.
g
o
PVC was found to be 84.69 C which was in accordance with
2
8
the literature value for unplasticized PVC. The plasticized
Thermo Gravimetric Analysis:
The thermogram of all PVC plasticized and non plasticized
sheets are shown in figure 11. The degradation pattern for all
Figure 11: Thermo Gravimetric Analysis of the synthesized PVC sheets: virgin and
Figure 10: Glass transition curves obtained for PVC sheets: virgin and plasticized with
plasticized with THPRABA plasticizer
varying concentration of THPRABA
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Table5: Summarization of onset and end set temperatures, % weight loss, % ash content for PVC sheets: virgin and plasticized with THPRABA plasticizer
Peak 1
Peak 2
Sample Name Onset Temperature
End set Temperature Weight Loss Onset Temperature
End set Temperature Weight Loss Ash content
o
o
o
o
(
C)
( C)
%
( C)
( C)
%
%
PVCVIRGIN
2
2
68.99
78.23
346.21
57.29
454.99
527.83
22.79
20.343
THPRABA10
THPRABA20
THPRABA30
364.69
351.10
347.57
59.95
56.56
56.74
451.93
431.68
427.46
527.87
527.97
528.39
23.66
27.93
29.08
16.681
15.959
14.604
270.33
269.73
THPRABA40
THPRABA50
269.49
275.08
347.67
357.67
56.70
57.12
429.39
427.85
523.97
529.18
29.86
29.77
14.078
14.343
sheets remains same irrespective of the percentage of
plasticizer added. The first peak implies loss of HCl from PVC in
case of virgin sheet whereas for plasticized sheets the first
peak implies loss of HCl along with added plasticizer. The
released HCl catalyzed the degradation of PVC The loss of CO
2
from plasticizer moiety takes place in between the first step
and continues before the start of second degradation step.
The released HCl accelerates the formation of polyenes from
PVC chains due to dehydrochlorination. The second peak
determines the loss of polyenes from PVC chain. The onset and
end set temperatures for both peaks are mentioned in table
no 5.
The onset and end set temperature for all plasticized
sheets are lower than the virgin sheets and they gradually
increased as concentration of plasticizer increases for first
peak. For virgin PVC sheet on set and end set temperatures for
-
1
Figure 12: Plot of viscosity (Pa.s) versus shear rate (s ) of THPRABA and DOP
o
o
o
synthesized THPRABA plasticizer has found to be
comparatively higher than conventional DOP plasticizer. The
prepared plasticizer displayed shear thinning behaviour i.e. at
higher shear rate the viscosity gets decreased. The graph of
first and second peak are 268.99 C, 346.21 C, 454.99 C,
o
27.83 C resp. The onset and end set temperature values of
5
o
o
first weight loss peak are 278.23 C and 364.69 C for
o
THPRABA10 sheet which gradually decreases to 270.33 C and
-1
o
viscosity (Pa.s) versus shear rate (s ) has been shown in figure
2 for virgin and plasticized PVC sheets. The graph clearly
3
51.10 C resp. for THPRABA20 and remains almost same for
0 and 40 phr sheet. The THPRABA50 sheet however shows
1
3
shows that viscosity of PVCVIRGIN and THPRABA10 sheets
were almost constant with viscosity of THPRABA10 sheet
slightly lower than PVCVIRGIN. This clearly states that both
these materials are rigid, hard and difficult to process. The
slight increase in onset and end set temperatures by exhibiting
o
values of 275.08 C and 357.67 C for first weight loss resp. The
o
onset temperature values of second weight loss peak are
o
51.93 C for THPRABA10 sheet which gradually decreases to
4
o
27.85 C for THPRABA50 resp. and end set temperature values
4
o
have increased slightly from 527.87 C for THPRABA10 to
o
29.18 C for THPRABA50. The percent ash content for virgin
5
PVC sheet is found to be 20.343% which decreases to 16.681%
for THPRABA10 sheet. PVC sheets containing 20 to 50 phr
concentration do not exhibit gradual decrease in ash content
and are found to have values of 15.959%, 14.604%, 14.078%
and 14.343% for 20 to 50 phr THPRABA plasticized PVC sheets
resp. Thus it is very clear that there is no significant change in
temperature of PVC degradation due to addition of THPRABA
plasticizer.
Rheological Analysis:
-1
The plot of viscosity (Pa.s) versus shear rate (s ) for THPRABA
versus DOP and PVC plasticized with THPRABA including virgin
PVC is summarized in figure 12 and 13 resp. The viscosity of
-
1
Figure 13: Plot of viscosity (Pa.s) versus shear rate (s ) obtained for PVC sheets: virgin
and plasticized with varying concentration of THPRABA plasticizer
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-
1
-1
-1
Figure 14: Plots of i) storage modulus (Pa) versus angular frequency (s ), ii) loss modulus (Pa) versus angular frequency (s ), iii) damping factor versus angular frequency (s ) and
-
1
iv) complex viscosity (Pa.s) versus angular frequency (s ) PVC sheets: virgin and plasticized with varying concentration of THPRABA plasticizer
viscosity for 20 to 50 phr sheets almost remains constant
well illustrated in figure 14. The rate of decrease of storage
-1
up to shear rate 0.148 s and after that viscosity reduced
gradually. For THPRABA20 sheet the viscosity decreased up
modulus was slightly greater than loss modulus which can
explain more viscous nature of PVC sheets than elastic
nature on addition of THPRABA plasticizer. As the
concentration of plasticizer in PVC was increased values for
both storage modulus and loss modulus has decreased
gradually. However the values of damping factor increases
-1
to shear rate 0.953s and then viscosity remains constant
irrespective of shear. However for 30 to 50 phr sheets
viscosity decreases with increased shear and implies their
shear thinning behaviour on addition of triester amide
thiophene plasticizer. The plasticizer molecules adjusts
itself between two adjacent PVC chains in such a way that it
breaks the inter molecular attraction between these chains
caused due to difference in electro negativity of chlorine
and hydrogen atoms on neighbouring chains. The
adjustment of assembled THPRABA plasticizer in PVC chains
results in making PVC soft, processable and flexible. Hence
at higher plasticizer concentration in PVC matrix the spindle
can move more freely displaying shear thinning behaviour
of PVC.
-1
with increasing angular frequency (s ) for plasticized PVC
sheets with THPRABA50 having largest value followed by
40, 20, 30 and 10 phr sheets. Whereas damping factor
value for PVCVIRGIN decreased with increasing angular
-1
frequency (s ) suggesting elastic behaviour of PVC sheet
than viscous nature in absence of plasticizer. The complex
viscosity (Pa.s) of virgin PVC sheet and that of THPRABA10
sheet are almost same at lower shear rate. However as
shear rate is increased the reduction in complex viscosity
for 10 phr sheet is clearly visible in comparison with
PVCVIRGIN sheet. It is observed that as the concentration
of plasticizer increases the complex viscosity decreases
gradually. The decrease in complex viscosity is more at
higher shear rate indicating shear thinning behaviour of
plasticizer.
The plot of storage modulus (Pa) versus angular
-1
frequency (s ), loss modulus (Pa) versus angular frequency
-1
-1
s ), damping factor versus angular frequency (s ) and
(
-1
complex viscosity versus angular frequency (s ) are shown
in figure 13 ( to iv) resp. The reduction in storage modulus
i
and loss modulus with decreasing angular frequency was
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8
.
.
Latini G. Biol. Neonate 2000; 78,269
Calò E., Greco A., Maffezzoli A., Polymer
Degradation and Stability, 2011, 96, 784
Conclusion
9
1
1
1
1
1
1
1
Triester amide plasticizer was synthesized from three step
reaction by reacting ricinoleic acid (RA) with diester amine
thiophene which was procured by Gewald multicomponent
reaction at high temperature followed by treating it with
benzoic acid (BA) in presence of 98% concentrated
sulphuric acid as catalyst. The obtained THPRABA plasticizer
was characterized by FT-IR and posses high viscosity than
DOP plasticizer due to presence of long carbon chain and
polar groups in plasticizer molecule which exhibit high
intermolecular forces of attraction. The nature of plasticizer
has been dark red coloured viscous liquid and plasticizer
absorption value was found to be 45.225 g per 100 g of
PVC. PVC sheets were prepared with 10, 20, 30, 40 and 50
phr concentration by using this novel plasticizer by
completely excluding commercial DOP plasticizer. The 50
phr PVC sheet have shown drastic reduction in tensile
modulus, tensile strength, flexural strength and crystallinity
by 71.618 %, 65.917 %, 65.606 % and 44.24 % resp. The
elongation at break was found to be 56 times more than
0. Mehta B., Kathalewar M., Sabnis A., Polym Int.
014, 63, 1456
1. Nihul P., Mhaske S., Shertukade V., Iranian Polym.
J., 2014, 23, 599
2. Baltacioğlu H., Balkösej D., J. Appl. Polym. Sci., 1999,
74, 2488
3. Savvashe P., Kadam P., Mhaske S., J. Appl. Polym.
Sci., 2015,132,41913
4. Waskitoajia W., Triwulandaria E., Haryono A.,
Procedia Chemistry, 2012, 4, 313
5. Gewald K, Schinke E, Bottcher H. Chem Ber., 1966;
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2
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646
5
o
,
29
1
C for 40 phr DOP sheet . The base ring for DOP carrying
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to PVC is benzene ring whereas in THPRABA plasticizer
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of two carbons i.e. ethyl chain and amide linkage by
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2
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2
2
2
2
2
2
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Acknowledgements:
.
Authors would like to acknowledge University Grants
Commission (UGC) for providing financial assistance to
carry out research work.
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