Synthesis and characterization of new aromatic polyesters derived from new aromatic di- and tri hydroxyl monomers with 4-phenylenediacrylic acid and malonic acid

Article abstract of DOI:10.14233/ajchem.2014.18082

In the present work, six new aromatic polyesters (PE1-PE6) have been synthesized in high yields from the polycondensation between di- and tri hydroxyl monomers containing methylene unit, Schiff-base linkages and pyridine heterocyclic ring with 4-phenylenediacrylic acid and malonic acid using dibutyltin dilaurate as catalyst. The structure analysis of the polymers has been carried out by using FT-IR and ¹H NMR spectroscopy. The monomers were characterized by FTIR and ¹H NMR. FT-IR technique confirmed the esterification of di and tri hydroxyl monomers by the acid in all the polymers.

Full text of DOI:10.14233/ajchem.2014.18082

Asian Journal of Chemistry; Vol. 26, No. 22 (2014), 7846-7852
ASIAN JOURNAL OF CHEMISTRY
http://dx.doi.org/10.14233/ajchem.2014.18082
Synthesis and Characterization of New Aromatic Polyesters Derived from New Aromatic
Di- and Tri Hydroxyl Monomers with 4-Phenylenediacrylic Acid and Malonic Acid
MOHAMMED A. MUTAR
Department of Chemistry, College of Education, University of Al-Qadisyia, Al-Qadisyia, Iraq
Corresponding author: E-mail: mohammeddw73@gmail.com
Received: 26 May 2014;
Accepted: 10 July 2014;
Published online: 6 November 2014;
AJC-16248
In the present work, six new aromatic polyesters (PE1-PE6) have been synthesized in high yields from the polycondensation between di-
and tri hydroxyl monomers containing methylene unit, Schiff-base linkages and pyridine heterocyclic ring with 4-phenylenediacrylic
acid and malonic acid using dibutyltin dilaurate as catalyst. The structure analysis of the polymers has been carried out by using FT-IR and
1
1
H NMR spectroscopy. The monomers were characterized by FTIR and H NMR. FT-IR technique confirmed the esterification of di and
tri hydroxyl monomers by the acid in all the polymers.
Keywords: Synthesis, Aromatic polyesters, 4-Phenylenediacrylic acid, Malonic acid.
reaction variables have strong influence on molecular weight
9
of the polymers as observed by Economy .
INTRODUCTION
The family of polyesters comprises all polymers with ester
functional groups in the polymer backbone. The chemistry of
the structural units connecting the ester group can be varied
over an immensely broad range, making the polyesters a
diverse group covering labile biomedical matrices to liquid
crystals, fibers and temperature resistant performance materials,
etc. Polyesters are the first family of synthetic condensation
Since the reaction parameters have prominent influence
on the rate of reaction and molecular weight of the polymers,
the polycondensation reaction was carried out at different
temperature with varying monomer concentration in different
solvent system over a range of reaction period and the yield
and the molecular weight of the resulting polymers were
studied. The polymers, synthesized by the condensation of
aromatic diols and diacids through a low temperature
procedure, were subjected to Fourier transform infrared (FTIR)
spectroscopy to study the chemical constituents of the mole-
cules and the molecular interaction among the polymer chains.
The chemical composition of the polymers can be determined
by the definite absorption bands in the spectrum.
1
-3
polymers . Polyesters can typically be formed by a stepwise
condensation reaction from difunctional monomers such as
2
diols and acids .
4
5
Recently, Takasu et al. and Liu et al. reported that the
HfCl (THF) complex more efficiently catalyzed the direct
4
2
polycondensation of diols and dicarboxylic acid compounds,
in which the procedure was a solution polycondensation in
6
o-xylene with reflux (about 144 ºC) for 24 h. Ober et al. synthe-
The analyses of the thermal properties of the polyesters
have been made by the help of the thermograms obtained from
the DSC studies. Furthermore, polyesters are known to possess
sized polyesters from dihydroxy compounds by polymerizing
diacid chlorides at 500 ºC for 24 h in inert atmosphere using
pyridine as proton acceptor. Polyesters were prepared by
10
enhanced thermal stabilities .
In the present work, a series of new aromatic polyesters
containing both methylene unit, Schiff-base linkages and
pyridine hetero cyclic ring have been synthesized in high yields
from the polycondensation between di- and tri hydroxyl
monomers with 4-phenylenediacrylic acid and malonic acid
using dibutyltin dilaurate as catalyst.
7
Ramireddy and coworkers by using pyridine as catalyst and
HCl scavenger, which was produced as a byproduct of the
esterification reaction with acid chlorides. The reaction was
allowed to proceed for 48 h at room temperature in dry
nitrogen. Polyesteramides with exact desired structure can be
synthesized from monomers with proper structure and func-
8
EXPERIMENTAL
tional groups. Sek et al. synthesized monomers and carried
out the polymerization reactions in boiling chlorobenzene at
Fourier transform infrared (FTIR) spectra were recorded
on a Shimadzu-FTIR-8400S spectrometer (Japan) with KBr
1
30 ºC in presence of pyridine in argon atmosphere .The

Vol. 26, No. 22 (2014)
Synthesis and Characterization of New Aromatic Polyesters 7847
-
1 1
pellets in the optical range of 4000-400 cm . H NMR spectra
were registered using a Bruker, 250Mhz, spectrometer, at
polymer laboratories Co Iran using DMSO as a solvent. The
solubility of the polymers was determined with (0.01 g) of
polyester in (2 mL) of a solvent.
ammonium acetate (7.5 g) and glacial acetic acid (20 mL)
was refluxed at 140-142 ºC for 2 h. Upon cooling, crystals
separated, which were filtered and washed first with acetic
acid (50 %) and then with cold ethanol. These product crystals
were recrystallized from absolute ethanol and then dried at
1
3,14
Absolute methanol, acetic acid, ammonium acetate,
dibutyltin dilaurate, all from (BDH/England); dichloro-
methane, hexane, procured from (BIOSOLVE). Hydrochloric
acid, salicylaldehyde, benzaldehyde all from (HiMedia);
diethyl ether obtained from (IGCC/England) while phenol,
p-aminophenol, 4-chlorobenzaldehyde, glacial acetic acid,
piperidine, pyridine, terephthalaldehyde, dimethyl sulphoxide,
m-cresol, N,N-dimethylacetamide, 4-(dimethyl amino)-
benzaldehyde, p-hydroxyacetophenone, tetrahydrofurane
obtained from Merck. Absolute ethanol from (Scharlab S.L),
malonic acid and N,N-dimethylformamide from Aldrich.
Synthesis of 1,1,1-tris(4-hydroxyphenyl)ethane (M1):
A mixture of 4-hydroxy acetophenone (2.72 g, 20 mmol),
phenol (4 g, 42 mmol), HCl catalyst (37.5 g) and thioglycolic
acid (0.5 g) promoter were placed in a three necked-round
bottom flask equipped with a condenser, mechanical stirrer
and thermometer and kept in a thermostat bath at 60 ºC for
60 ºC under vacuum .
Synthesis of M3: There are several methods for preparation
of the pyridine ring. Modified Chichibabin method is one of
1
5,16
the best methods for the preparation of a pyridine ring
,
which offers advantages such as good yield, available starting
material and potential for introducing different substituent’s
in the pyridine ring.
M3 is prepared by the condensation of one molecule of
benzaldehyde with two molecules of p-hydroxyacetophenone
in the presence of ammonium acetate and glacial acetic acid
at 140-142 ºC for 2 h (Scheme-III). This monomer was charac-
terized by FTIR.
HO
OH
O
CH3
CHO
C
N
Ammonium acetate
Glacial acetic acid
+
2
140-142 °C / 2 h
OH
6
transferred to cold water to quench the reaction. Then, the
h. After a definite period of time, the reaction mixture was
Scheme-III: Synthesis of M3
11
product was washed, dried to yield 5 g (82 % wt) of brown
powder (Scheme-I). The monomer has characterized by FTIR.
Synthesis of M4: M4 is prepared by the condensation of
one molecule of 4-chlorobenzaldehyde with two molecules
of p-hydroxyacetophenone in the presence of ammonium
acetate and glacial acetic acid at 140-142 ºC for 2 h (Scheme-
IV). This monomer was characterized by FTIR.
CH
3
HO
C
OH
O
C
HCl/HSCH
2
COOH
HO
CH
3
+
2
OH
6
0 °C/6 h
HO
OH
OH
O
CH
3
Scheme-I: Synthesis of M1
CHO
C
N
Ammonium acetate
Glacial acetic acid
+
2
Synthesis of M2: This monomer was prepared by the
140-142 °C / 2 h
condensation of terephthalaldehyde (1.34 g, 10 mmol) and
p-aminophenol (2.2 g, 20 mmol) in 15 mL of methanol, by
boiling the mixture under reflux at 120 ºC for 3 h. The preci-
pitated was filtered and recrystallized from methanol and dried
Cl
OH
Cl
Scheme-IV: Synthesis of M4
1
2
in a vacuum desiccators to yielding 2.5 g (79 % wt) of very-
light yellow crystals. m.p. 205-210 ºC (Scheme-II). This
1
monomer was characterized by FTIR and H NMR spectra.
Synthesis of M5: M5 is prepared by the condensation of
one molecule of 4-(dimethylamino)benzaldehyde with two
molecules of p-hydroxyacetophenone in the presence of
ammonium acetate and glacial acetic acid at 140-142 ºC for
2 h (Scheme-V). This monomer was characterized by FTIR.
CHO
NH
2
Methanol
20 °C / 3 h
HO
N
C
H
C
H
N
OH
+
2
1
HO
OH
O
CH
3
CHO
OH
CHO
C
N
Scheme-II: Synthesis of M2
H
3
C
CH
3
Ammonium acetate
Glacial acetic acid
+
2
140-142 °C / 2 h
General synthesis of M3, M4, M5, M6: In a round-
bottomed flask (150 mL) equipped with a reflux condenser, a
mixture of aldehyde derivative (10 mmol), that showed in
H
3
C
CH
3
NH
2
OH
NH
2
(
Table-1), p-hydroxyacetophenone (2.72 g, 20 mmol),
Scheme-V: Synthesis of (M5)
TABLE-1
SYNTHESIS OF MONOMERS (M3, M4, M5, M6)
Substance
Weight of
monomer (g)
Yield
(% wt)
Monomers
Colour
m.p. (ºC)
278-282
Aldehyde derivative
Benzaldehyde
Weight (g)
1.06
M3
M4
M5
M6
2.6
77
79
78
79
Greenish yellow
Blackish brown
Blackish red
4-Chloro benzaldehyde
4-(Dimethylamino) benzaldehyde
Salicylaldehyde
1.41
2.94
2.97
2.80
Viscous liquid
Viscous liquid
205-210
1.49
1.22
Reddish brown

7
848 Mutar
Polyesters
Asian J. Chem.
TABLE-2
SYNTHESIS OF POLYESTERS (PE1-PE6)
Monomers
Diacid
Malonic acid
Malonic acid
Diacid
(g/mmol)
Dihydroxy
(g/mmol)
Yield
(% wt)
Colour
Dihydroxy
M1
PE1
PE2
PE3
PE4
PE5
PE6
2.08 / 20
1.04 / 10
2.18 / 10
2.18 / 10
2.18 / 10
4.36 / 20
3.06 / 10
3.16 / 10
3.39 / 10
3.72 / 10
3.82 / 10
3.55 / 10
76
79
77
78
79
79
Light brown
Light pink
Light yellow
Black
M2
p-Phenylenediacrylic acid
p-Phenylenediacrylic acid
p-Phenylenediacrylic acid
p-Phenylenediacrylic acid
M3
M4
M5
Brown
M6
Deep brown
Synthesis of M6: M6 is prepared by the condensation of
8
2.5
5.0
one molecule of salicylaldehyde with two molecules of p-
hydroxyacetophenone in the presence of ammonium acetate
and glacial acetic acid at 140-142 ºC for 2 h. This monomer
7
67.5
0.0
1
was characterized by FTIR and H NMR spectra.
6
HO
OH
O
CH
3
52.5
45.0
CHO
C
CH
C
3
N
OH
Ammonium acetate
Glacial acetic acid
HO
OH
+
2
140-142 °C / 2 h
37.5
OH
OH
OH
3
0.0
4
000 3600 3200 2800 2400 2000 1800 1600 1400 1200 1000 800 600 400
Scheme-VI: Synthesis of M6
–1
Wavelength (cm
)
Synthesis of polyesters (PE1- PE6): In this section, we
used polycondensation method for synthesis of a series of two
new polyesters from the direct polycondensation reaction of
malonic acid with two new different aromatic dihydroxy
monomers (M1, M2), respectively and four new polyesters
from the direct polycondensation reaction of p-phenylene-
diacrylic acid with four new different aromatic dihydroxy
monomers (M3, M4, M5 and M6), respectively, by using the
dibutyltin dilaurate catalyst [0.15 wt. (%)] (Scheme-VII)
Fig. 1. FTIR spectrum of M1
1
20
105
9
0
5
7
(
giving rise to the PE series. The materials were obtained as
Table-2). The materials were dried under vacuum at 50 ºC
60
45
HO
N
C
H
C
H
N
OH
17
powders . These polymers have a soft segment such as methy-
lene unit, vinyl moiety and Schiff-base groups and pyridine
heterocyclic ring in main chain for improving solubility in
organic solvents. These polyesters were characterized by FTIR
30
4000 3600 3200 2800 2400 2000 1800 1600 1400 1200 1000 800 600 400
–
1
)
Wavelength (cm
1
and H NMR spectra.
Fig. 2. FTIR spectrum of M2
RESULTS AND DISCUSSION
The FTIR spectrum of M1 as shown in (Fig. 1) which
-1
indicates absorption band at (3271 cm ) to (-OH group), (3062
HO
N
C
C
N
OH
-
1
-1
cm ) to (aromatic -CH Str), (2985 cm ) to (aliphatic -CH Str)
H
H
-
1
and absorption bands around (1666-1512 cm ) show the
presence of the aromatic ring.
The FTIR spectrum of (M2 Schiff-Base) is shown in
-
1
(
(
Fig. 2) which indicates absorption bands at (3311 cm ) to
-1
-OH group), (3078 cm ) to (aromatic -CH stretching), (2922
-1
cm ) to (aliphatic -CH stretching) and absorption bands around
(
H NMR spectrum of M2, is shown in Fig. 3 assigns the
1
0
8
6
ppm
4
2
-
1
1612-1546 cm ) show the presence of the aromatic ring.
1
1
Fig. 3. H NMR spectrum of M2
following chemical shifts; δ (2.5) ppm for DMSO, δ (3.5) ppm
s, 2H) for C-H, δ (3.4) (s ,2H) for OH group, δ (6.8 -8.2)
ppm(s, 12H ) for Ar-H group.
-
1
(
(1671-1656 cm ) show the presence of the aromatic ring and
-
1
(1590-1523 cm ) to heteroaromatic ring (C=N).
The FTIR spectrum of M4 as shown in (Fig. 5) which
The FTIR spectrum of M3 as shown in (Fig. 4) which
-1
-1
indicates absorption band at (3377cm ) to (-OH group), (3138
-1
cm ) to (aromatic -CH stretching), absorption bands around
indicates absorption band at (3366 cm ) to (-OH group), (3148
-1
cm ) to (aromatic -CH stretching), absorption bands around

Vol. 26, No. 22 (2014)
Synthesis and Characterization of New Aromatic Polyesters 7849
CH
C
3
Dibutyltin dilaurate
catalyst
O
C
O
C
CH3
C
O
C
O
C
HO
OH
H2
C
H
C
2
O
O
2
HO
OH
+
160 °C / 1 h
x
P.E1
OH
O
C
O
O
CH
C
2
O
C
O
C
Dibutyltin dilaurate
catalyst
O
C
O
H
C
2
H
2
C
HO
OH + HO
N
C
H
C
H
N
OH
C
O
N
C
H
C
H
N
O
160 °C / 1 h
x
P.E2
O
O
C
Dibutyltin dilaurate
catalyst
O
O
N
N
HO
C
C
C
C
H
C
H
OH
+
HO
OH
C
C
H
C
H
C
H
C
H
C
O
O
H
H
160 °C / 1 h
x
P.E3
O
C
O
C
Dibutyltin dilaurate
catalyst
O
C
O
C
N
N
HO
C
H
C
H
C
H
C
H
OH
+
HO
OH
C
H
C
H
C
H
C
H
O
O
160 °C / 1 h
x
P.E4
Cl
N
Cl
N
O
C
O
C
Dibutyltin dilaurate
catalyst
O
C
O
C
HO
C
H
C
H
C
H
C
H
OH
+
HO
OH
C
H
C
H
C
H
C
H
O
O
160 °C / 1 h
x
P.E5
H C
3
CH
3
3
H C
CH
3
NH
2
NH
2
O
C
O
C
Dibutyltin dilaurate
catalyst
O
C
O
C
N
N
2
HO
C
C
C
C
OH
+
HO
OH
C
H
C
H
C
H
C
H
O
O
160 °C / 1 h
H
H
H
H
x
P.E6
OH
O
C
O
CH
CH
CH
CH
C
O
Scheme-VII: Synthesis of PE1-PE6
-
1
-1
(2806 cm ) to (aliphatic -CH stretching), absorption bands around
(
(
1670-1654 cm ) show the presence of the aromatic ring,
-
1
-1
1592-1521 cm ) to heteroaromatic ring (C=N) and (811 cm )
-1
(1668-1648 cm ) show the presence of the aromatic rings and
-1
to (C-Cl).
The FTIR spectrum of M5 as shown in (Fig. 6) which
(1587-1517 cm ) to heteroaromatic ring (C=N).
The FTIR spectrum of M6 as shown in (Fig. 7) which
-1
-1
indicates absorption band at (3356 cm ) to (-OH group), (3138
-1
cm ) to (aromatic -CH stretching), absorption bands around
indicates absorption bands at (3366 cm ) to (-NH
-1
cm ) to (-OH group), (3044 cm ) to (aromatic -CH stretching),
2
group), (3311
-1

7
850 Mutar
Asian J. Chem.
6
6
5
5
4
4
3
3
5
0
5
0
5
0
5
0
1
00
9
8
7
6
5
4
0
0
0
0
0
0
N
N
HO
OH
HO
OH
OH
4
000 3600 3200 2800 2400 2000 1800 1600 1400 1200 1000 800 600 400
–
4000 3600 3200 2800 2400 2000 1800 1600 1400 1200 1000 800 600 400
–1
Wavelength (cm )
1
Wavelength (cm
)
Fig. 4. FTIR spectrum of M3
Fig. 7. FTIR spectrum of M6
6
5
4
3
3
2
1
0.0
2.5
5.0
7.5
0.0
2.5
5.0
4
N
HO
OH
N
HO
OH
Cl
OH
000 3600 3200 2800 2400 2000 1800 1600 1400 1200 1000 800 600 400
–
1
Wavelength (cm
)
ppm
10
8
6
4
2
0
1
Fig. 8. H NMR spectrum of M6
Fig. 5. FTIR spectrum of M4
9
8
7
6
5
0
7
6
5
4
3
2
1
0
0
0
0
0
0
0
0
0
0
0
O
C
O
C
CH
3
H
C
2
O
C
O
N
x
HO
OH
O
C
H
3
C
CH
3
40
O
O
CH
2
C
3
0
NH
2
4000 3600 3200 2800 2400 2000 1800 1600 1400 1200 1000 800 600 400
–1
Wavelength (cm )
4
000 3600 3200 2800 2400 2000 1800 1600 1400 1200 1000 800 600 400
–
1
Wavelength (cm
)
Fig. 9. FTIR spectrum of PE1
Fig. 6. FTIR spectrum of M5
-1
-1
1779-1756 cm ) to (-C=O Str, ester), (1108 cm -C-O Str, ester)
(
and absorption bands around (1635-1530 cm ) show the
-
1
(
(
1679-1658 cm ) show the presence of the aromatic ring and
-1
-
1
1599-1527 cm ) to heteroaromatic ring (C=N).
1
presence of the aromatic ring.
FTIR spectrum of PE3: The FTIR spectrum of PE3 as
shown in (Fig. 11) which indicates absorption band at (3135
H NMR spectrum of M6, is shown in Fig. 8 assigns the
following chemical shifts; δ (2.5) ppm for DMSO, δ (4.5) ppm
s, 3H) for OH, δ (5.7), δ (6.5 -8.5) ppm (s, 14H ) for Ar-H
(
-1
cm ) to (aromatic –CH stretching), absorption bands around
group.
-1
1673-1650 cm ) show the presence of the aromatic ring, (1533
(
cm ) to vinyl segment, (1762-1752 cm ) to (-C=O str, ester),
-1
-1
Characterization of polyesters (PE1-PE6)
-1
-1
1102 cm -C-O str, ester) and (1588-1522 cm ) to hetero-
(
aromatic ring (C=N).
FTIR spectrum of PE1: The FTIR spectrum of PE1 as
shown in (Fig. 9) which indicates absorption band at (3070
-1
-1
cm ) to (aromatic -CH str), (2989 cm ) to (aliphatic -CH str),
FTIR spectrum of PE4: The FTIR spectrum of (PE4) as
shown in (Fig. 12) which indicates absorption band at (3119
-
1
-1
1789-1766 cm ) to (-C=O str, ester), (1100 cm -C-O str,
(
-1
-1
cm ) to (aromatic –CH stretching), absorption bands around
ester) and absorption bands around (1646-1532 cm ) show
the presence of the aromatic ring.
-1
(1669-1649 cm ) show the presence of the aromatic ring, (1537
cm ) to vinyl segment, (1781-1749 cm ) to (-C=O str, ester),
-1
-1
FTIR spectrum of PE2: The FTIR spectrum of PE2 as
shown in (Fig. 10) which indicates absorption band at (3066
-1
cm ) to (aromatic -CH Str), (2988 cm ) to (aliphatic -CH Str),
-1
-1
1155 cm -C-O str, ester), (1583-1524 cm ) to heteroaromatic
(
ring (C=N) and (796 cm ) to (C-Cl).
-1
-1

Vol. 26, No. 22 (2014)
Synthesis and Characterization of New Aromatic Polyesters 7851
8
7
6
5
4
3
2
1
0
0
0
0
0
0
0
0
60
O
C
O
C
N
C
H
C
H
C
H
C
H
O
O
x
5
4
3
2
0
0
0
0
H C
3
CH
3
NH
2
O
C
O
C
10
0
H
2
C
O
N
C
C
N
O
H
H
x
4
000 3600 3200 2800 2400 2000 1800 1600 1400 1200 1000 800 600 400
–
600 400
800 2400 2000 1800 1600 1400 1200
1
000 800
4000 3600 3200
2
1
)
–1
Wavelength (cm
Wavelength (cm
)
Fig. 10. FTIR spectrum of PE2
Fig. 13. FTIR spectrum of PE5
9
8
7
6
5
4
3
2
0
0
0
0
0
0
0
0
1
05.0
9
9
8
7.5
0.0
2.5
O
C
O
C
N
C
H
C
H
C
H
C
H
O
O
x
O
C
O
C
N
75.0
C
H
C
H
C
H
C
H
O
O
O
x
O
C
CH
CH
6
6
7.5
0.0
CH
CH
C
O
4
000 3600 3200 2800 2400 2000 1800 1600 1400 1200 1000 800 600 400
–
1
4000 3600 3200 2800 2400 2000 1800 1600 1400 1200 1000 800 600 400
Wavelength (cm
)
–
1
Wavelength (cm
)
Fig. 11. FTIR spectrum of PE3
Fig. 14. FTIR spectrum of PE6
8
7
6
5
4
3
2
0
0
0
0
0
0
0
O
C
O
N
C
H
C
H
C
H
C
H
C
O
O
x
O
O
C
O
N
C
H
C
H
C
H
C
H
C
O
O
O
C
x
CH
CH
Cl
4
000 3600 3200 2800 2400 2000 1800 1600 1400 1200 1000 800 600 400
CH
CH
C
–1
Wavelength (cm
)
O
Fig. 12. FTIR spectrum of PE4
FTIR spectrum of PE5: The FTIR spectrum of PE5 as
shown in (Fig. 13) which indicates absorption band at (3362
-
1
-1
cm ) to (-NH
2
group), (3112 cm ) to (aromatic -CH stret-
-1
ppm
10
8
6
4
2
0
ching), (2812 cm ) to (aliphatic -CH stretching), absorption
-
bands around (1642-1659 cm ) show the presence of the
1
1
Fig. 15. H NMR spectrum of PE6
-1
-1
aromatic ring, (1532 cm ) to vinyl segment, (1743-1788 cm )
-1
to (-C=O str, ester), (1163 cm -C-O str, ester) and (1581-
1
Solubility of polyesters: Solubility of polyesters PE1-
-1
529 cm ) to heteroaromatic ring (C=N).
FTIR spectrum of PE6: The FTIR spectrum of PE6 as
shown in (Fig. 14) which indicates absorption band at (3122
PE6 was qualitatively tested in organic solvents and the results
are summarized in Table-3. The method that attempt to enhance
their process abilities and solubilities were either by intro-
ducing bulky groups, flexible linkages, or molecular asym-
metry into the polymer backbones. In this work, the attachment
of bulky pendant groups in polymer backbone not only could
provide an enhanced solubility because of decreased packing
-1
cm ) to (aromatic –CH stretching), absorption bands around
-1
(1651-1638 cm ) show the presence of the aromatic ring, (1529
cm ) to vinyl segment, (1782-1747 cm ) to (-C=O str, ester),
-1
-1
-1
-1
1178 cm -C-O str, ester) and (1579-1527 cm ) to hetero-
(
aromatic ring (C=N).
density and crystallinity, but also could impart an increase in
18
1
H NMR spectrum of PE6, is shown in Fig. 15 assigns the
following chemical shifts; δ (2.5) ppm for DMSO, δ (5.7), δ
T
g
by restricting the segmental mobility .
One of the major objectives of this work was producing
polyesters with improved solubility. The solubility was investi-
(
6.7 -8.0) ppm (s, H ) for Ar-H group.

7
852 Mutar
Solvent
Asian J. Chem.
TABLE-3
SOLUBILITY OF POLYESTERS: PE1-PE6
Polyesters
PE1
+ –
+ –
+ +
+ –
+ +
+ –
+ –
+ +
+ +
+ –
PE2
PE3
+ +
+ +
+ –
PE4
PE5
+ +
+ +
+ –
+ +
+ –
+ –
+ +
+ –
+ +
+ –
PE6
+ –
+ +
+ +
+ –
+ +
+ –
+ –
+ +
+ +
+ +
DMAc
DMF
+ +
+ +
+ –
+ +
+ –
++
NMP
Pyridine
m-Cresol
THF
+ +
+ –
+ –
+ +
+ + +
+ –
+ +
+ –
+ –
+ –
+ + +
+ –
+ –
CHCl3
CH Cl
+ +
+ +
+ + +
+ +
+ +
+ –
2
2
DMSO
+ +
+ +
Conc. H SO
2
4
Full Soluble. +++ Soluble at room.T. ++ Partially Soluble. + –.
gated as (0.03 g) of polymeric sample in (3 mL) of a solvent.
All of the newly synthesized polyesters have good soluble in
common polar and dipolar aprotic solvents without need for
heating.
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