Studies on thermal, microbial behaviours of copoly(azo-maleimide-acrylic acid/vinyl acetate) and terpoly(azo-maleimide-acrylic acid-vinyl acetate): Synthesis and characterization

Article abstract of DOI:10.14233/ajchem.2016.19769

A terpolymer based on polymerizable monomer unit of N-substituted maleimide associated with azo moiety as a pendent group, acrylic acid and vinyl acetate was chemically architected. The preparation of terpolymer was accelerated by free radical polymerizat

Full text of DOI:10.14233/ajchem.2016.19769

Asian Journal of Chemistry; Vol. 28, No. 7 (2016), 1607-1610
A
SIAN
J
OURNAL OF HEMISTRY
C
http://dx.doi.org/10.14233/ajchem.2016.19769
Studies on Thermal, Microbial Behaviours of Copoly(azo-maleimide-Acrylic Acid/Vinyl Acetate)
and Terpoly(azo-maleimide-acrylic acid-vinyl acetate): Synthesis and Characterization
*
JYOTI CHAUDHARY, SUMAN JINGER , SWATI PUROHIT and HARSHADA JOSHI
Department of Polymer Science, Mohanlal Sukhadia University, Udaipur-313 001, India
*Corresponding author: E-mail: sumanjinger@gmail.com
Received: 19 December 2015;
Accepted: 8 February 2016;
Published online: 31 March 2016;
AJC-17858
A terpolymer based on polymerizable monomer unit of N-substituted maleimide associated with azo moiety as a pendent group, acrylic
acid and vinyl acetate was chemically architected. The preparation of terpolymer was accelerated by free radical polymerization using
AIBN initiator at 70 2 °C in THF solvent. Copolymers of maleimide with acrylic acid/vinyl acetate have also been synthesized,
characterized and results were comparatively analyzed with terpolymer. The thermal properties of terpolymer and copolymers such as
glass transition temperature (Tg) and thermal decomposition were determined by DSC and TGA analysis respectively. The weight molecular
weight (Mw) and number average molecular weight (Mn) were determined by gel permeation chromatography. Density measurement,
1
solubility test, viscosity test, elemental analysis, FT-IR, H NMR spectral analysis were used to characterization of terpolymer and
copolymers.
Keywords: Terpolymer, Copolymer, Maleimide, Acrylic acid, Vinyl acetate, TGA, DSC.
activities. In this paper, we report the synthesis of homopolymer
4-N-phenylethanamideazo-3-N-(4-nitrophenyl)maleimide
[HPANMI], copolymers [4-N-phenylethanamideazo-3-N-(4-
nitrophenyl)maleimide-co-acrylic acid] [C1PANMI], [4-N-
phenylethanamideazo-3-N-(4-nitrophenyl)maleimide-co-
vinylacetate] [C2PANMI], and terpolymer [4-N-phenylethan-
amideazo-3-N-(4-nitrophenyl)maleimide-acrylic acid-vinyl-
acetate] [T1PANMI], using free radical initiator and organic
polar solvent.
INTRODUCTION
It has been a great interest to developed a variety of synthetic
route to form olefinic-imide frames known as maleimide using
different derivatives of amines and modified to achieved multi-
functionalities in N-substituted maleimide polymers [1-3].
N-substituted maleimides and derivatives with acrylates
have been extensively used in polymerization reactions to form
thermally stable, high performing synthetic materials such as
high strength composites, molding composites, adhesives and
also production of superabsorbent polymers, oil treatment
chemicals, water treatment chemicals, detergent intermediates
and water absorbent polyacrylic acid polymer [4]. A few co-
polymers and terpolymers of N-substituted maleimide
containing monomer, acrylic acid and vinyl acetate have been
synthesized to investigate their applicability areas in high
performance materials as a thermally stable and resist materials
towards microbial conditions [5-7], which is influenced by
hydrogen bond interaction [8,9].
In the present study, we are mainly concerned with the
influence of H-bonding on the structure and glass transition
temperature (Tg) of newly copolymers and terpolymer
consisting of N-substituted maleimide with acrylates and
vinyls.Acrylic acid (AA) and vinyl acetate (VA) into polymeric
chain of maleimide were introduced to increase the thermal
performance with high flexibility and also analyzed microbial
EXPERIMENTAL
p-Amino acetanilide and maleic anhydride were recrysta-
llized from acetone (LobaChemei,AR).AIBN (Fisher Scientific,
AR), THF, DMF and methanol (Sigma Aldrich, AR) are used
without any purification.
Synthesis of N-(4-N-phenyl ethanamide)maleimide
[PEMI] (I): The N-(4-N-phenyl ethanamide) maleimide PEMI
(I) was prepared by the reaction of p-amino acetanilide (0.1
mol) and maleic anhydride (0.1 mol) according to reported
method [10]. The monomer N(4-N-phenyl ethanamide azo-
3-N-(4-nitro phenyl)maleimide [PANMI] (II) was synthesized
by diazotization reaction (Scheme-I). Copolymerization and
terpolymerization were carried out to form polymers of PANMI
accompanied by THF solvent and AIBN initiator at 60-70 °C
(Schemes I and II). Resulting polymers appearance are orange-
brown colour.

1608 Chaudhary et al.
Asian J. Chem.
Yield of polymerization: The percentage yield was diffe-
red in polymerization process of homopolymer, copolymers
and terpolymer which are refer to the using different solvent-
initiator couples-system and according the production, It was
observed that the percentage yield in THF-AIBN system is
high as compared to DMF, 1,4-dioxane solvents.
band. Stronger the hydrogen bond, greater the absorption and
peak was shifted towards lower wave number than the normal
absorption peak.
Physical properties: Solubility of homopolymer, copo-
lymers and terpolymer was examined in our laboratory by
using solvents of varying parameters and it was seems that
these were perfectly soluble in THF, DMF, DMSO and partially
soluble in acetone, 1,4-dioxane and ethyl acetate. Some other
characterization like viscosity, density also determined. Mole-
cular weight was measured by gel permeation chromatography
(GPC) technique. The molecular weight distribution in polymers
varies from very low to very high range of molecular weight.
Poly dispersity index of all polymers were also determined by
same technique. Terpolymer reveals high molecular weight
due to presence of three co-monomer units to create dense
molecular structure. The number average molecular weight
(Mn), weight average molecular weight (Mw) and poly disperity
(Mw/Mn) are given in Table-2.
RESULTS AND DISCUSSION
Infrared spectra were recorded on a FTIR Perkin Elmer
spectrometer mode RX-I using KBr pellets for sample prepa-
ration. The spectrum information was collected in the range
of 4000-250 cm-1. The 1H NMR spectral data was recorded in
DMSO-d6 with TMS as an internal standard reference. Spectra
and spectral values are shown in Table-1. The peak of double
bonded carbons in five membered imide ring was disappear
in homopolymer, copolymers and terpolymer pervasive the
polymerized and unpolymerized units and enable to poly-
merization in concern compounds at double bonded carbon
atoms.The hydrogen bonding shown between carbonyl-oxygen
and hydroxyl-hydrogen, confirmed by the carbonyl stretching
bands are shifted in downward zone with broad absorption
Thermal studies: Thermogravimetric analysis curves
shown the thermal behaviour of homopolymer, copolymers
and terpolymer in Fig. 1. Which is analyzed on Perkin Elmer
NH2
COOH
O
O
O
NH2
NH
N
HCl / 0-5 °C
NaNO2
+
DMF, Stirr.
4 h
DMF, 60-65 °C
Conc. H2SO4, P2O5
+
O
O
O
NO2
4-Nitro aniline
Maleic anhydride
NHCOCH3
NHCOCH3
NHCOCH3
4-Aminoethanamide
Maleamic acid
4-N-Phenylethanamide
maleimide [PMI]
CH
CH2
O
O
n
N
m
R
H2C
CH
O
O
N
N
+
R
THF/AIBN, 70 °C
N
N
NO2
NHCOCH3
[PANMI]
N
NO2
NHCOCH3
C1PANMI / C2PANMI
Scheme-I: Synthesis of monomer [PANMI] and copolymers: [C1PANMI] and [C2PANMI]
R = –COOH, –COOCH3
CH
CH2
CH
COOCH3
CH2
n
m
O
O
N
N
O
COOH
CH2
O
CH2
N
THF/AIBN, 70 °C
+
CH
CH
+
COOCH3
COOH
N
NO2
Acrylic acid
Vinyl acetate
N
N
NO2
NHCOCH3
[PANMI]
NHCOCH3
T1PANMI
Scheme-II: Synthesis of terpolymer: [T1PANMI]

Vol. 28, No. 7 (2016)
Synthesis of Ter Polymer Based on N-substituted Maleimide 1609
TABLE-1
FT-IR AND 1HNMR SPECTRAL DATA OF PANMI, HPANMI, C1PANMI, C2PANMI AND T1PANMI
Technique
PANMI
HPANMI
3363
1713
-
1603
1373
3074
1515
C1PANMI
3359
1710
-
1602
1396
3073
1515
C2PANMI
3372
1714
-
1601
1379
3070
1516
1445, 1344
836
T1PANMI
3355
1714
-
1602
1392
3071
1515
1447, 1314
837
Characteristics
N-H Stretch of amide
C=O Sym. & Asym. stretch of imide
C-C stretch of CH=CH
3300
1702
1666
1603
1372
3095
1534
C=O Stretch of amide
C-N-C stret. of N – Subs. maleimide
C-H stretch of aromatic CH=CH
N=N stretch in aromatic
-NO2 Asym. And sym. Stretch
P-substituted Ar
FT-IR
(cm-1)
1407, 1345 1444, 1344 1447, 1396
836
730
836
741
838
753
751
752
Ortho- substituted Ar
7.43, 7.19
7.20
7.65
7.69
-
7.07
-
10.05
7.91, 7.68
7.19
8.19
8.27
-
7.91, 7.06
7.53
8.27
8.22
11.89
-
7.93, 7.66
7.68
8.23
8.29
11.76
-
8.14, 7.91
7.73
8.10
8.22
10.73
-
Phenyl proton of ortho to N of imide
Phenyl proton of meta to N of imide
AzoSubs.Phenyl proton of ortho to N=N-C
Azp Substituted Phenyl protons of meta to N=N-C
-COOH
(CH=CH)
-[CH-CH]n-
-CONH
1H NMR
(δ ppm)
-
3.50
10.07
3.52
10.08
3.46
10.09
3.40
10.09
TABLE-2
DENSITY, INTRINSIC VISCOSITY, MOLECULAR WEIGHT OF HOMOPOLYMER, COPOLYMER AND TERPOLYMER
ρ (g/cm3)
0.5319
0.9013
0.8069
0.9246
η (dl/g)
0.121
0.278
0.153
0.518
Polymer code
Mn
Mw
Poly dispersity index (PDI)
H-PANMI
C1PANMI
C2PANMI
T1PANMI
928.9
984.2
956.8
977.7
1104.8
1255.9
1175.1
1313.7
1.189
1.276
1.228
1.343
TABLE-3
WEIGHT LOSS (%) OF H-PANMI, C1PANMI, C2PANMI AND T1PANMI AT VARIOUS TEMPERATURE RANGE FROM THE TGA
Weight loss (%)
Polymer code
200 °C
94.48
94.27
90.80
94.54
300 °C
83.05
80.09
78.68
79.51
4000C
67.67
65.86
59.92
67.31
500 °C
53.21
52.56
42.49
49.53
600 °C
42.19
43.00
35.77
39.76
700 °C
36.29
38.04
32.38
35.30
H-PANMI
C1PANMI
C2PANMI
T1PANMI
100.3
100
pyrisl TGA with thermal range of 30 to 1000 °C and analyzed
accompanied by heating rate of 10 °C/min. in inert atmosphere
of nitrogen. The results of percentage weight loss suffered
from 200 to 700 °C at 100 intervals are shown in Table-3. All
polymer decomposed by continuous degradation mechanism
according to the resultant thermograms and shown excellent
stability towards high temperature (Table-3). DSC analysis was
also performed on NETZSCH DSC 204. The value of Tg for
homopolymer, copolymers and terpolymer were summarized
in Table-4. The Tg value also concluded the terpolymer having
significance glass transition point with following flexibility
in polymeric rigid spine due to mixing of vinyl acetate and
thermal behaviour was maintained by the active participation
of intermolecular hydrogen bonding.
A comparison of Tg of the present terpolymer [T1PANMI]
and copolymers [C1PANMI], [C2PANMI] showed significant
observation in thermal behaviour. It was intimated that
incorporation of synthesized N-substituted maleimide unit in
vinyl acetate (VA) and acrylic acid (AA) has increased Tg value
of comonomers (VA, AA) due to formation of H-bonding in
polymer structures thus it was demonstrated a valuable changes
in low temperature stable objects to revealed good thermal
(a)
(b)
(c)
(d)
90
80
70
60
50
40
32.33
39.21 100
200
300
400
500
600
719.5
Temperature (°C)
Fig. 1. TGA Thermograms of (a) H-PANMI (b) C1PANMI (c) C2PANMI
(d) T1PANMI
TABLE-4
THERMAL BEHAVIOUR OF H-PANMI,
C1PANMI, C2PANMI AND T1PANMI
Polymer code H-PANMI C1PANMI C2PANMI T1PANMI
Tg (°C)
169.1
1.806
167
120.1
0.270
188.9
0.153
1.302
∆Cp* (J/g K)

1610 Chaudhary et al.
Asian J. Chem.
stability and also create flexibility in highly rigid spine of
maleimide polymers. Although homopolymer of maleimide
monomer shown good Tg value and thermal susceptibility but
that is exist in rigidity and to overcome this type of rigidness,
vinyl acetate and acrylic acid used in homopolymer to
enhanced flexibility. The equivalent Tg values of polymers were
confirmed the establishment of “H-bonding” in co- and ter-
polymers. That’s why, flexibility/softness of vinyl acetate and
thermal property of maleimide collaborated and supported
against individual drawbacks with help of “H-bonding” which
is reflecting by acrylic acid to architect high performing
copolymer and terpolymer comparatively.
Microbial activity: In sequence to explore biological
activities of homopolymer, copolymers and terpolymer were
evaluated against various microorganism such as Esherichia
aerogenes, Staphylocous aureus bacteria and Aspergillus niger,
Alternaria solani fungi with DMSO as solvent with sample
concentration was 500 µg/mL. Synthesized polymers revealed
good antibacterial activity against used bacteria and fungi. The
antimicrobial activity of homopolymer, copolymers and
terpolymer were shown due to presence of heteroatom matrix
in polymers (Table-5).
Conclusion
Synthesis through free radical homopolymerization of
H-PANMI, copolymerization of C1PANMI, C2PANMI and
terpolymerization of T1PANMI have been investigated. The
characterization of homo-, co- and ter-polymers has been carried
out through elemental analysis, FTIR, 1H NMR spectral analysis,
solubility test and density, viscosity measurement. The thermal
properties were investigated by TGA and DSC. C1PANMI,
C2PANMI and T1PANMI exhibited good thermal stability and
Tg value with sustain flexibility than their homopolymer due
to the presence of secondary force “H-bonding” and polymers
was degrade in continuation according thermograms. The
synthesized all polymers showed good antimicrobial features,
could be played significantly in concern applications.
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H-PANMI
C1-PANMI
C2-PANMI
T1-PANMI
6
10
7
6.7
10.8
8
9
16
9
8.5
13
10
18
14
11
15