Materials Sciences and Applicatio n, 2011, 2, 771-776
doi:10.4236/msa.2011.27106 Published Online July 2011 (http://www.SciRP.org/journal/msa)
Studies on Interacting Blends of Acrylated Epoxy
Resin Based Poly(Ester-Amide)s and Vinyl Ester
Resin
Pragnesh N. Dave1*, Nikul N. Patel2
1Department of Chemistry, KSKV Kachchha University, Gujarat, India; 2Institute of Technology, Nirma University, Ahmedabad,
India.
Received January 24th, 2011; revised March 23rd, accepted May 27th, 2011.
ABSTRACT
Epoxy resin based Unsaturated poly(ester-amide) resins (UPEAs) can be prepared by many methods but here these
were prepared by reported method [1]. These UPEAs were then treated with acrylotl chloride to afford acrylated
UPEAs resin (i.e. AUPEAs). Interacting blends of equal proportional AUPEAs and vinyl ester epoxy (VE) resin were
prepared. APEAs and AUPEAs were characterized by elemental analysis, molecular weight determined by vapour
pressure osmometer and by IR spectral study and by thermogravimetry. The curing of interacting blends was monitored
on differential scanning calorimeter (DSC). Based on DSC data in situ glass reinforced composites of the resultant
blends have been prepared and characterized for mechanical, electrical and chemical properties. Unreinforced blends
were characterized by thermogravimetry (TGA).
Keywords: Unsaturated Bisamic Acid, Epoxy Resin, Unsaturated Poly(Ester-Amide) Resin (Upeas), Acrylation, Vinyl
Ester (VE) Resin, Differential Scanning Calorimetry, Thermogarvimetry, Glass Reinforced Compos ites
1. Introduction
Both the polyesters and polyamides discussed have par-
ticular individual properties and applications. Hence
many researchers have synthesized co-poly (ester-am-
ide)s from different raw materials in order to obtain the
properties and applications of the individual ones into
one segment. Some of the poly (ester-amide)s synthe-
sized by different researchers. The three polymer candi-
dates namely epoxy resin, unsaturated poly ester and
polyamides are most widely versatile industrial materials
and have broad spectrum of characteristics for wide ap-
plications ranging from aerospace to micro electronics.
They are also important as laminating resins, moulding
composites, fibers, films, surface coating resins, fiber
cushion [3,4]. Particularly Polyamides material used in
the form of fibers as especially thermoplastics of par-
ticular used in engineering applications. The glass fiber
reinforced nylon plastics are now of substantial impor-
tance due to rigidity and creep resistance. Polyamides are
also used in fiber application, automotive industries,
valve covers, coatings [5,6].
Merging of all three segments (i.e. epoxy, ester and
amide) into saturated and unsaturated polymer chain has
been recently reported from our Indian scientists [7-10].
Certain properties of resins may also be improved via
interact of with the other unsaturated resin is another
possibility. In order to improve certain properties of such
reported USPEAs their blending with commercial vinyl
ester epoxy resin is possible. While vinyl ester resin is
versatile industrial resin today [11,12] Hence the present
paper comprises studies of interacting blending of re-
ported unsaturated poly(ester-amide) resin with vinyl
ester (VE) resin. The glass fiber reinforced composites of
these blends have been fabricated and characterized by
chemical, mechanical and electrical properties. The
whole work is scanned in Scheme 1.
2. Materials and Methods
2.1. Materials
Commercially available epoxy resin, diglycidyl ether of
bisphenol-A and vinyl ester epoxy resin was obtained
from local market.
The specification of diglycidyl ether of bisphenol-A
(DGEBA) are as follows:

Studies on Interacting Blends of Acrylated Epoxy Resin Based Poly(Ester-Amide)s and Vinyl Ester Resin 772
O
O
O
+H2NNH2
Maleic Anhydride
(2.0 Mole)
0-5 0C
HOOC CH CH OC CO HNNH CH CH COOH
Unsaturated Bisamic Acids(1a-c)
Diglycidylether of Bisphenol-A
CH CH OC
CO HNNH CH
CH
OOC COO CH2CH2
CH
OH
OR1
n
Unsaturated Poly(Ester-Amide) Resin (UPEAs 2a-c)
R
Aromatic Diamines
(1.0 Mole)(a-c)
Acrylol Chloride
O
CO
CH CH2
Acrylated Unsaturated Poly(Ester-Amide) Resin (AUPEAs 3a-c)
Benzoyl Peroxide
0.05% Hydroquinone
Stirr well forten minutes at 850C
AUPEAs-VE Blends (4a-c)
Glass Fiber Reinforced Composites (5a-c)
Stirrer 50% of AUPEAs and 50% of VE resin atfor 1-hour
Where,
(b) (c)
R=
R1= C
CH3
CH3
O O
CH2
CH
OH
O
CH2
CH CH OC CO HNNHCH CH
OOC COO CH2CH2
CH OR1
80 0C
CH2
CH
O CH2
O
CO
CH CH2
n
VE =C
CH3
CH3
O CH2CH2CH CH2CO CHCH2
OH
CH
CH2
CO
CH
CH2
OH
0-5˚C
R
R
R
85˚C
80˚C
H2
CO2
S
NH2 H2N
4,4'-methylenedianiline
O H2NNH2H2NNH2
4,4'-oxydianiline 4,4'-sulfonyldianiline
(a)
Scheme 1. Synthesis Steps.

Studies on Interacting Blends of Acrylated Epoxy Resin Based Poly(Ester-Amide)s and Vinyl Ester Resin 773
1) Epoxy equivalent weight, 190.
2) Viscosity 40 - 100 poise at 25˚C.
3)Density at 25˚C, 1.16 - 1.17 g/cm.
Vinyl ester epoxy.
The aromatic diamines used for the preparation of un-
saturated poly(ester-amide) resin are,
1) 4,4’-methylenedianiline
2) 4,4’-oxydianiline
3) 4,4’-sulfonyldianiline
Plain weave fibers, in the form of E-glass woven fab-
ric (poly (ester-amide) compatible) 0.25 mm thick (Un-
nati Chemicals, India) of a real weight 270 g·m–2 were
used for composite fabrication. All other chemicals used
were of pure grade.
2.2. Synthesis of Unsaturated Bisamic Acids
The unsaturated bisamic acid was prepared by a simple
addition reaction of maleic anhydride and diamines.
These were prepared by using method reported in the
literature [7,8]. The general procedure for the synthesis
of unsaturated bisamic acid is as follows.
To a well-stirred solution of maleic anhydride (2.0
mole) in dry acetone, the solution of diamine (1.0 mole)
in dry acetone was gradually added at 0˚C -5˚C within 30
minutes. After complete addition of the diamine, the re-
action mixture was further stirred for half an hour at
room temperature. The resulting unsaturated bisamic acid
was then filtered, washed with dry acetone and air-dried.
Unsaturated bisamic acid was obtained in the form of
free flowing powder. The reaction scheme for the syn-
thesis of unsaturated bisamic acid is shown in Scheme 1.
2.3. Synthesis of Unsaturated Poly(Ester-Amide)
Resin and Acrylated Poly(Ester-Amide)
Resin
The unsaturated poly(ester-amide) resin (UPEAs) was
prepared by following the same method reported in [7,8]
The general procedure is as follows:
Diglycidylether of Bisphenol-A (DGEBA) (1.0 mole)
and unsaturated bisamic acid (1.0 mole) were charged in
three necked flask equipped with a mechanical stirrer.
The unsaturated bisamic acid was then treated with di-
glycidylether of Bisphenol-A according to method re-
ported for reaction of epoxy resin and carboxylic group
[13]. To this 8.0% of the total weight of above, triethyl-
amine (TEA) was added as a base catalyst. The reaction
mixture was slowly heated up to 85˚C with continuous
stirring till the acid value fell below 60 mg KOH/gm.
The resultant resin was then discharged and called un-
saturated poly(ester-amide) resin (UPEAs) and their de-
tails are furnished in Table 1. Further reaction of all
these unsaturated poly(ester-amide) resin (UPEAs) was
carried out with acryloyl chloride (i.e. acrylation) and the
resultant products called acrylated poly(ester-amide)s
(APEAs) and their details are furnished in Table 2.
2.4. Synthesis of Acrylated Poly(Ester-Amide)
Resin and Vinyl Ester Resin Blend
When the acid value of acrylated poly(ester-amide)s fell
below 55 mg KOH/gm, 0.05% of hydroquinone was
added as an inhibitor. The whole reaction stirred well for
ten minutes maintaining the temperature at 85˚C. Then
add 50% of APEAs and 50% of vinyl ester (VE) resin
was added and stirred well at 80˚C for one hour. The
resultant APEAs-VE blends were obtained in the form of
viscous syrup.
3. Analysis and Thermal Study
3.1. Elemental Analysis
The C, H, N content of unsaturated poly(ester-amide)s
(UPEAs) and acrylated poly(ester-amide)s (APEAs) was
estimated by means of Thermofinagan 1101 flash ele-
Table 1. Characterization of UPEAs (2a-c).
Elemental analysis (Wt%) Calc. / (Found)
UPEAs
%C %H %N
No. of –OH group
per repeating unit Number average molecular weight (Mn ) ± 60
2a 65.62/64.23 5.72/5.50 6.43/5.83 1.96 3902
2b 64.06/63.83 5.20/4.86 3.64/3.15 1.82 3828
2c 60.29/60.12 4.90/4.63 3.43/3.05 1.81 4206
Table 2. Characterization of AUPEAs (3a-c).
Elemental analysis (Wt%) Calc. / (Found)
AUPEAs
%C %H %N
No. of double bonds per
repeating unit Number average mo- lecular weight (Mn) ± 60
3a 65.75/65.37 5.74/5.48 3.19/2.63 3.91 4133
3b 64.38/63.87 5.02/4.70 3.19/2.91 3.76 4135
3c 63.22/62.88 4.93/4.62 3.13/2.61 3.81 4428

Studies on Interacting Blends of Acrylated Epoxy Resin Based Poly(Ester-Amide)s and Vinyl Ester Resin 774
mental analyzer (Italy). The IR spectra were recorded in
Kerr pellets on a Nicollet 760 D spectrometer. The num-
ber average weight of unsaturated poly(ester-amide)s
(UPEAs) and acrylated poly(ester-amide)s (APEAs) was
estimated by non-aqueous conductometric titration fol-
lowing by method reported in the literature [14]. Pyridine
was used as a solvent and tetra-n-butyl ammonium hy-
droxide was used as a titrant.
3.2. Thermal Study
Curing of all APEAs-VE blends were carried out on a
differential scanning calorimeter (DSC) by using benzoyl
peroxide as a catalyst. A Du Pont 900 DSC was used for
this study. The instrument was calibrated using standard
indium metal with known heat of fusion (ΔH = 28.45 J/g).
Curing was carried out from 30˚C - 300˚C at 10˚C min–1
heating rate. The sample weight used for this investiga-
tion was in the range of 4 - 5 mg along with an empty
reference cell. The results are furnished in Table 3.
Unreinforced cured samples of APEAs-VE blends
were subjected to thermogravimetric analysis (TGA) on
Du Pont 950 thermo gravimetric analyzer in air at a
heating rate of 10˚C min–1. The sample weight used for
this investigation was in the range of 4 - 5 mg. The re-
sults are furnished in Table 4.
4. Composite Fabrication
The composites were prepared by using E-type of glass
fiber. The glass fiber: APEAs-VE blend ratio is 60:40
(40% APEAs-VE blends). Suspensions of APEAs-VE
blends were prepared in tetrahydrofuran (THF). In the
above polymer suspension, 1% of ethylene dimethy-
lacrylate (as a cross linking agent) with 0.05% benzoyl
peroxide (as an initiator) were added and mixed well.
The mixture was applied with a brush to a 200 mm × 200
mm glass cloth and the solvent was allowed to evaporate.
The ten dried prepregs prepared in this way were then
stacked one on top of another and pressed between steel
plates coated with a “Teflon” film release sheet and
compressed under 70 psi pressure. The prepregs stacks
were cured by heating it in an autoclave oven at around
140˚C for about 6 hour. The composites so obtained were
cooled to 45˚C - 50˚C before the pressure was released.
4.5. Composite Characterizations
4.5.1. Chemical Resistance Test
The resistances against Chemicals of the composites
were measured according to ASTM D 543. The results
are furnished in Table 5.
4.5.2. Mechanical and Electrical Testing
1) The Flexural strength was measured according to
ASTM D 790.
2) The Compressive strength was measured according
to ASTM D 695.
3) The Impact strength was measured according to
ASTM D 256.
4) The Rockwell hardness was measured according to
ASTM D 785.
5) The Electrical strength was measured according to
ASTM D 149.
6) The Tensile elongation was tested according to
Table 3. DSC Curing of UAPEAs-Vinyl ester epoxy resin Blends (4a-c).
Curing Temperature (˚C) UAPEAs-VE resin Blends Ti Tp Tf
4a 130 151 172
4b 116 147 174
4c 126 138 186
Table 4. TGA of Unreinforced Cured Samples of UAPEAs-Vinyl ester epoxy resin Blends (5a-c)-BPO system.
% Weight loss at various temps. (˚C) from TGA
UAPEAs-VE resin
Blends 150˚C 300˚C 450˚C 600˚C 750˚C
5a 2.01 9.34 64.23 77.32 81.34
5b 1.87 9.21 68.56 76.63 79.34
5c 1.71 8.03 65.25 75.87 80.06
Table 5. Chemical, Mechanical and Electrical Properties of Composites Based on APEAs-MMA Blends.
% Change on exposure to 25%
(W/V) NaOH
Composites Thickness Weight
Compressive
strength (MPa)Impact Strength (MPa)Rockwell hardness (R)
Electrical
strength
(in air)
(kV/mm)
5a 0.78 1.07 460 424 111 22.65
5b 0.81 1.10 467 456 104 19.45
5c 0.79 1.02 478 447 106 23.35

Studies on Interacting Blends of Acrylated Epoxy Resin Based Poly(Ester-Amide)s and Vinyl Ester Resin 775
ASTM 0638.
All mechanical and electrical tests were performed
using three specimens and their average results are sum-
marized in Table 5.
5. Results and Discussion
The unsaturated bisamic acids were prepared by the reac-
tion of malelic anhydride (2.0 mole) and aliphatic dia-
mines (1.0 mole) by following method reported in litera-
ture [7,8]. Unsaturated poly(ester-amide)s (PEAs) was
prepared by reaction of epoxy resin (DGEBA) with un-
saturated bisamic acids using triethylamine (TEA) as a
base catalyst. The post reactions of all these unsaturated
poly(ester-amide)s (PEAs) were carried out with acryloyl
chloride. The resultant products are called acrylated poly
(ester-amide)s (APEAs). Blending of acrylated poly(es-
ter-amide)s APEAs with vinyl ester (VE) resin was also
carried out. The resultant products are called APEAs-VE
blends.
The C, H, N content of all the unsaturated poly(ester-
amide)s (PEAs) and acrylated poly (ester-amide)s
(APEAs) were estimated by means of Thermofinagan
1101 Flash Elemental Analyzer (Italy). The values of C,
H, N of each of the unsaturated poly(ester-amide)s (PEAs)
and acrylated poly (ester-amide)s (APEAs) were consis-
tent with their predicted structures and are furnished in
Tables 1 and 2. The number average molecular weight of
both unsaturated poly (ester-amide)s (PEAs) and acry-
lated poly (ester-amide)s (APEAs) were estimated by
non-aqueous conductometric titration method [14]. Their
results are furnished in Tables 1 and 2, respectively. The
results indicate that the degree of polymerization of both
unsaturated poly (ester-amide)s (PEAs) and acrylated
poly (ester-amide)s (APEAs) is about 6. The IR spectra
were consistent with the ones expected from the struc-
tures of the PEAs (3a-c) and APEAs (4a-c).
Numbers of hydroxyl group present per repeating unit
in unsaturated poly(ester-amide)s (PEAs) was also ana-
lyzed by employing acetylating method [15]. Also, acry-
lated poly(ester-amide)s (APEAs) were characterized for
the presence of double bonds per repeating unit employ-
ing mercury-catalyzed bromate-bromide method [16].
Satisfactory results were found and the results are fur-
nished in Tables 1 and 2 respectively.
Curing of all these APEAs-VE blends were carried out
on a differential scanning calorimeter (DSC) by using
benzoyl peroxide as a catalyst. The data of DSC thermo-
grams of all APEAs-VE are furnished in Table 3.
The unreinforced cured samples of APEAs-VE blends
were also analyzed by thermo gravimetric analysis
(TGA). The result reveals that the cured sample starts
their degradation at about 150˚C and their initial weight
is about 2% - 3%. This small weight loss may be due to
either in sufficient curing of components used or due to
the catalyst used. A weight loss of about 10% - 11% is
found at 300˚C. However, the rate of decomposition in-
creases very rapidly between 300˚C to 450˚C and the
products are lost completely beyond 750˚C. TGA data of
all the samples are shown in Table 4.
The glass and carbon fiber reinforced composites of all
APEAs-VE blends were prepared based on their DSC
data. The composites were characterized for their chemi-
cal, mechanical and electrical properties. Their results are
furnished in Table 5. The results shows that composites
have good chemical resistant property, good mechanical
and electrical strength.
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