Fabrication and characterization of novel high-performance fluorinated polyimides with xanthene pendent architecture: Study of thermal, photophysical, antibacterial and heavy metal ion adsorption behavior

Article abstract of DOI:10.1016/j.jfluchem.2016.10.010

Two series of new fluorescent polyimides (PIs) with different functional groups such as flexible ether linkages, substituted imidazole, photoactive xanthene pendant, and electron withdrawing CF₃groups were prepared using novel monomers and thre

Full text of DOI:10.1016/j.jfluchem.2016.10.010

Accepted Manuscript
Title: Fabrication and characterization of novel
high-performance fluorinated polyimides with xanthene
pendent architecture: Study of thermal, photophysical,
antibacterial and heavy metal ion adsorption behavior
Author: Seyed Mojtaba Amini Nasab Soheila Esmaili Mehdi
Taghavi Zahed Shami
PII:
S0022-1139(16)30381-5
DOI:
Reference:
http://dx.doi.org/doi:10.1016/j.jfluchem.2016.10.010
FLUOR 8875
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Received date:
Revised date:
Accepted date:
2-1-2016
26-9-2016
15-10-2016
Please cite this article as: Seyed Mojtaba Amini Nasab, Soheila Esmaili, Mehdi Taghavi,
Zahed Shami, Fabrication and characterization of novel high-performance fluorinated
polyimides with xanthene pendent architecture: Study of thermal, photophysical,
antibacterial and heavy metal ion adsorption behavior, Journal of Fluorine Chemistry
http://dx.doi.org/10.1016/j.jfluchem.2016.10.010
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Fabrication and characterization of novel high-performance
fluorinated polyimides with xanthene pendent architecture:
Study of thermal, photophysical, antibacterial and heavy metal
ion adsorption behavior
a
a
b
a
Seyed Mojtaba Amini Nasab *, Soheila Esmaili , Mehdi Taghavi , Zahed Shami
aDepartment of Chemistry, Faculty of Science, University of Kurdistan, Sanandaj,66177-
5175, Iran.
1
bPolymer Chemistry Research Laboratory, Faculty of Science, Shahid Chamran
University of Ahvaz, 61357-43337, Iran
*
Corresponding author. Tel.; +98-8733624133; FAX: +98-8733624133
E-mail address: m.amininasab@uok.ac.ir
1

Graphical abstract
Two series of novel fluorinated aromatic polyimides derived from two new monomers
with commercially available dianhydrides were successfully synthesized. Diamines and
synthesized polyimides were fully characterized and their properties such solubility,
thermal, photophysical, antibacterial activity and ability for removal of environmentally
toxic heavy metal ions were investigated.
Highlight



Fabrication and characterization of novel fluorinated polyimides was carried out.
The effects of CF polar group substitution on polyimides properties was studied.
and xanthene units in the polymer backbone improving polymers
3
Bulky CF
solubility.
3


Extraction capability for heavy metal ions from aqueous solutions was
investigated.
Novel polyimides were also tested for antibacterial activity.
ABSTRACT
Two series of new fluorescent polyimides (PIs) with different functional groups such as
flexible ether linkages, substituted imidazole, photoactive xanthene pendant, and electron
withdrawing CF groups were prepared using novel monomers and three commercially
3
2

available dianhydrides. The structures of two diamines and PIs were fully characterized
1
by elemental analysis, FT-IR and H NMR spectroscopy. The prepared polymers were
amorphous with inherent viscosity ranged from 0.38 to 0.66 dL/g, they were readily
soluble in a variety of organic solvents and tough transparent films were prepared by
solution casting method. These polymers showed useful level of thermal stability having
°
°
high glass transition (T
g
) (235-303 C) and 10% weight loss (402-498 C) temperatures
°
with more than 62% residue at 800 C under N
2
. They exhibited strong UV-vis absorption
in solutions and in films. Photoluminescence efficiency was affected by the chemical
structure of the polymers and their quantum yields ranged from 7 to 21%. The
antibacterial activity of diamines and two polymers were investigated against Gram
positive and Gram negative bacteria. Also, the prepared PIs were investigated for the
3
+
2+
2+
2+
2+
removal of heavy metal ions such as Cr , Pb , Hg , Cd and Co from aqueous
solutions at pH 7-8.
Keywords: Fluorinated polyimides; Xanthene; Thermal stability, Antibacterial, Heavy
metal ions.
1
. Introduction
Aromatic polyimides (PIs) are an important class of polymeric materials with good
mechanical, chemical and electrical properties and favorable balance of thermal and
hydrolytic stability [1-3]. However, this class of polymers suffers from poor
3

processability due to limited solubility in common organic solvents, high glass-transition
) and softening (T ) temperatures. Therefore, an increasing number of researches have
(T
g
s
been directing towards the design and development of structurally modified aromatic PIs
with increased solubility and better processability [4-10]. The most common approaches
for increasing solubility and lowering T
CF groups, flexible linkages, and bulky pendant in the side or backbone chains of
polymers [11-20]. In this respect, the introduction of both flexible ether linkages and -
CF groups into the aromatic polyimides backbone improves processability and solubility
g
and T are the introduction of heterocyclic rings,
s
-
3
3
of polymers without much loss of good thermal and thermo-oxidative stability [21-25].
On the other hand, the incorporation of fluorinated substituents into the polymer
backbone further decreases the regularity of polymer chains leading to the weakening of
intermolecular hydrogen bonding and chain packing efficiency, resulting in a decrease in
crystallinity and improvement in solubility in organic solvents [26-30]. Moreover, CF
and bulky heterocyclic groups along the polymer backbones are expected to give rise to
restricted segmental mobility, leading overall to a high T and enhanced solubility at the
3
g
same time. These groups make packing-disruptive moieties which hinder the chain
packing [31-34]. The rigidity based on the aromaticity and polarity of the heteroaromatic
rings contributes to the thermal and chemical stability and retention of mechanical
properties of the resulting polymer at elevated temperatures [35-40]. However, the
polarizability resulting from the heteroatoms such as nitrogen atoms in the imidazole ring
improves the polymer’s solubility in organic solvents [41-46]. Imidazole heterocyclic
ring and its derivatives such as lophine (substituted imidazole) are useful n-type building
blocks with high electron affinity and good thermal stability and have been successfully
4

incorporated in small molecules and polymers as an electron-transport component.
Moreover, imidazole and its derivatives have been extensively studied for their
applications in medicine as biologically active substances. However, the use of
antimicrobial agent blended in a polymer matrix can give rise to the migration towards
the surface, which decreases the antimicrobial activity during the lifetime of polymer
application. For this reason, recently several research groups have tested the use of
different antimicrobial agents covalently bonded to the polymer chains [47, 48].
Treatment of industrial wastewaters polluted with toxic heavy metal ions has been a
great concern of environmental protection agencies all over the world. Among different
technologies for removal of the heavy metal ions from aqueous solution, adsorption is a
reliable and widely used method due to its simplicity and easy operational conditions
[
49]. Polymers containing heterocyclic functional groups such as imidazole group not
only chelate cationic metal ions but can also adsorb anionic adsorbates through
electrostatic interaction [50, 51].
In this work, synthesis and characterization of two series of novel organosoluble and
thermostable PIs are reported based on diamines containing CF polar groups, flexible
3
ether linkages (-O-), and substituted imidazole and bulky xanthene pendants. The
1
prepared PIs were characterized by FT-IR, H NMR, and elemental analysis, and their
properties including solubility, thermal stability, photophysical, antibacterial activity and
3
+
2+
2+
2+
2+
adsorption of heavy metal ions such as Cr , Pb , Hg , Cd and Co from water were
investigated.
2
. Results and discussion
2
.1. Synthesis and characterization of diamines
5

Two new diamines were synthesized according to the synthetic route shown in
Scheme 1. The purity of all compounds was checked by thin-layer chromatography
(TLC) using ethyl acetate/hexane mixture. Compound 1 was successfully synthesized
from 2-naphthol and terephthalaldehyde as starting materials in the presence of p-
toluenesulfonic acid (p-TSA). The structure of compound 1 was identified by elemental
1
-1
analysis, FT-IR and H NMR. The FT-IR spectrum showed absorption band at 1251 cm
1
related to the C-O-C stretching vibration, and H NMR spectrum showed signal at 9.75
ppm related to the C-H of aldehyde group. Compound 2 was synthesized by nucleophilic
aromatic substitution reaction of 4,4'-dihydroxybenzil with 4-fluoronitrobenzene in the
presence of K
2
CO in DMSO solution. The reaction between compounds 1 and 2 in
3
ammonium acetate and glacial acetic acid, which is a well-known synthetic method for
preparation of imidazole ring, was used to synthesize the dinitro compounds. The FT-IR
-1
spectrum of DNb (Fig. 1) showed the absorption bands at 1536 and 1340 cm due to
asymmetric and symmetric stretching vibrations of -NO
2
group, and absorption band at
-1
1
1
240 cm was assigned to C-O-C stretching vibration. In the H NMR spectrum of DNb,
the signal at 10 ppm related to the aldehyde group disappeared and a new signal was
observed in the region of 12-13 ppm due to the N-H of imidazole ring. The catalytic
hydrogenation of the nitro groups into the corresponding amino groups were
accomplished by using hydrazine hydrate in ethanol in the presence of a catalytic amount
1
of Pd/C. The structure of intermediates and diamines were characterized by FT-IR, H
NMR, and elemental analysis, the extracted data have been given in the experimental
-1
section. After reduction, absorption bands at 1536 and 1340 cm related to NO
2
groups
-1
disappeared and new bands were observed at 3396 and 3372 cm due to N-H stretching.
6

1
Fig. 2 shows the H NMR spectrum of DAb, signals in the region of 5.44, 5.50 and 6.79
ppm were related to the protons of amino group and those attached to the xanthene ring,
respectively.
2
.2. Polymer synthesis and characterization
The PIs were prepared from polycondensation reaction between the synthesized
novel
diamines,
2-(4-(14H-dibenzo[a,j]xanthen-14-yl)phenyl)-4,5-bis(4-(4-
aminophenoxy)phenyl)-1H-imidazole (DAa) and 2-(4-(14H-dibenzo[a,j]xanthen-14-
yl)phenyl)-4,5-bis(4-(4-amino-2-(trifluoromethyl)phenoxy)phenyl)-1H-imidazole (DAb)
with aliphatic and aromatic dianhydrides, as illustrated in Scheme 2. The PIs were
synthesized in one pot using two-step reactions; fabrication of poly(amic acid) (PAA)
precursors followed by chemical imidization. The chemical imidization of PAA was
carried out in acetic anhydride/pyridine mixture. The PIs were light brown powder and
the yields were in the region of 85-92% after extraction with refluxing methanol for 24 h
to remove low fraction oligomers. The inherent viscosity of PIs was in the range of 0.38-
0
.66 dL/g indicating medium molecular weights. The FT-IR spectrum of PIb2 (Fig. 1)
-1
showed the characteristic absorption bands at 1781 and 1727 cm corresponding to the
-1
asymmetric and symmetric C=O stretching, at 1376 cm related to C-N stretching, and at
-1
1
1
109 and 832 cm due to the imide ring deformation. Fig. 3 shows H NMR spectrum of
the representative PIa2. The hydrogen atoms in the repeating unit of this polymer were
appeared as signals at 6.79, 6.99-8.71, and 12.42 ppm corresponding to the xanthenes
ring, aromatic protons, and N-H of imidazole ring, respectively.
7

2
.3. Solubility of PIs
The solubility of PIs was tested in different organic solvents at concentration of 5%
(
w/v), and the results were tabulated in Table 1. These polymers exhibited good
solubility behavior in polar aprotic solvents such as NMP, N,N-dimethylacetamide
DMAc), N,N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), and even in less
(
polar solvents like pyridine and m-cresol. The good solubility of these PIs might be
attributed to the flexible ether linkages, bulky groups such as xanthenes and polar
hetroaromatic imidazole ring. The bulky groups prevent close chain-packing and allow
the solvent molecules to diffuse into the polymer chains and interact with polar groups in
the polymer backbone. The solubility of these polymers is higher or comparable with the
solubility of previously reported PIs [52]. In addition, the solubility varies depending
upon the dianhydride used. PIs synthesized from aliphatic dianhydride (PI3) exhibited
good solubility behavior in Py and m-cresol in comparison with PIs prepared from
aromatic dianhydride. Also the PIs prepared from diamine containing CF
better solubility than PIs obtained from diamine without CF group. The attachment of
bulky CF groups would decrease polymer interchain interactions such as hydrogen
3
group showed
3
3
bonding and generally disturbs the co-planarity of aromatic units. This can reduce
packing efficiency and crystallinity, which is expected to lead to the enhanced solubility.
It should be noted that good solubility in low-boiling point solvents is critical for
preparing objects at a relatively low processing temperature which is desirable for
advanced microelectronics manufacturing applications. The water uptake determines the
final application of high performance materials. The absorbed water diminishes T and
g
8

influence mechanical and electrical properties. However, in the membrane technology the
greater water uptake implied better performance. The present PIs showed low water
uptake in the range of 2.05-2.94% (Table 1). This could mainly be attributed to the
polymer hydrophobicity due to the presence of trifluoromethyl groups. Among these PIs,
the PIb exhibited the lowest water absorption which can be due to the highest fluorine
content in its repeating unit. PIa2 obtained from dianhydride 2, showed the highest water
uptake due to the presence of carbonyl linkage which forms hydrogen bonding with water
molecules.
2
.4. UV-vis absorption and fluorescence characteristics
The photoluminescence (PL) spectra of the diamines and PIs in dilute (0.2 g/dL)
NMP solutions were shown in Fig. 4. The UV-vis spectra of dilute NMP solution of the
-5
diamines (2×10 M) and the corresponding PIs (0.2 g/dL) are shown in Fig. 4A. The
absorption spectra of PIs in dilute NMP solution (0.2 g/dL) and in films were almost
identical with maximum at λab=308-322 nm, which is related to the π-π* transitions
resulting from the conjugation between the aromatic rings and nitrogen atoms. The
optical properties of these PIs could also be elucidated from cut-off wavelength observed
in the UV-visible spectra and the results were listed in Table 2. Fig. 4B shows the PL
emission spectra of the monomers and PIs in dilute NMP solution. The excitation
wavelength used was 315 nm in all cases. The maximum emission wavelength (λem) of
the diamines in NMP solution was observed at 422-427 nm. The PIs solutions and thin
films showed broad fluorescent emission spectra with λem=422-467 nm and λem=423-470
9

nm, respectively. To measure the PL quantum yields (Φ
g/dL) in NMP were prepared. A 0.1 N solution of quinine in H
as a standard [40]. The Φ values were 27-31% for the diamines, 19-21% for the aliphatic
f
), dilute polymer solutions (0.2
2
SO = 0.53) was used
4
(Φ
f
f
PIs, and 7-12% for the aromatic PIs. The lower quantum yield of PI2 can be attributed to
dissipation of energy into heat as a result of facilitated bond rotation in the bridging
carbonyl group between two phenyl rings. The blue shift and higher fluorescence
quantum yield of the aliphatic PIs compared with the aromatic PIs were suggested to be
attributed to reduced conjugation and capability of charge-transfer complex formation by
the aliphatic dianhydrides with the electron-donating diamine moiety in comparison to
the stronger electron-accepting aromatic dianhydrides [53]. Because of the lower
capability of charge-transfer, the PI3 showed a light colour and high optical transparency.
Intermolecular interaction between the xanthene and imidazole moieties in the polymer
backbone is negligible, presumably because both chromophores have similar absorption
and emission properties.
2
.5. Thermal properties
DSC and TGA were applied to evaluate the thermal properties of the PIs. The DSC
and TGA curves of the PIs were shown in Fig. 5, and thermal analysis data from the
original curves are summarized in Table 3. The absence of melting peak in the DSC
thermograms supported the generally amorphous nature of the PIs. The amorphous nature
of these polymers can be attributed to bulky pendent group which decreased the intra and
inter-chain interactions, resulting in loose polymer chain packaging and aggregates. The
°
T
g
values of PIs were in the range of 235-303 C. As expected, T
g
values depended on the
structure of the dianhydride component; it decreased with increasing flexibility of the PI
1
0

backbone based on the structure of dianhydride. The bridging carbonyl group between
two phenyl rings present in 3,3',4,4'-benzophenone tetracarboxylic dianhydride (BTDA)
facilitated bond rotation and reduced the T
Among the synthesized PIs, PI3 based on bicyclic aliphatic dianhydride showed the
lowest T value because of the absence of rigid phenyl groups that inhibit molecular
motion. Also, the results indicated that T values of the PIb containing -CF groups was
lower than that of PIa without -CF groups. This might be a result of increase in free
volume caused by the introduction of the bulky -CF substituents. Although the increased
rotational barrier caused by the bulky aromatic pendent groups of diamines enhanced the
values, but the solubility and processability of these polymers improved significantly
due to the presence of ether linkages in the main chain and amorphous nature of the
polymer. Thermal stability of these polymers was evaluated by TGA under N
g
of PI2 in comparison with the T
g
of PI1.
g
g
3
3
3
T
g
2
atmosphere and the curves were shown in Fig. 5B. All these polymers exhibited good
°
thermal stability with insignificant weight loss up to 370 C under N
2
. TGA data in Table
°
3
show that the temperature of 10% weight loss was in the range of 402-498 C, and the
°
residual weights were in the range of 23-62% at 800 C. Also, the results indicated that
PIs containing -CF groups had lower thermal stability. The Char yield can be used as
3
criteria for evaluating limiting oxygen index (LOI) of the polymers in accordance with
Van Krevelen and Hoftyzer equation [54]. LOI= 17.5 + 0.4 CR where CR= char yield.
°
For all the polymers LOI values were calculated based on their char yield at 800 C. PI1
had a better thermal stability than PI2 because the carbonyl-bridging group between the
two phenyl rings in the backbone of PI2 increased the flexibility and decreased the
thermal stability of polymer. According to Table 3, it is clear that aromatic PIs have
1
1

higher thermal stability and LOI values compared to the aliphatic PIs. This can be
pertained to the rigid structure of aromatic dianhydrides compared to the flexible
structure of aliphatic dianhydrides. Therefore, the PI1 and PI3 showed the highest and the
lowest thermal stability due to the presence of rigid phenyl and flexible aliphatic units in
the backbones, respectively.
2
.6. Antibacterial activity
The antibacterial properties of the diamines and polymers (PIa1 and PIb1) were
evaluated by using two Gram-positive bacteria S. aureus and B. subtilis and two Gram-
negative bacteria E. coli and P. aeruginosa. In addition, the finding towards inhibition of
microorganisms was correlated with a standard antibiotic tetracycline. The obtained
results were summarized in Table 4 and screened in Fig. 6. The antibacterial screening
revealed that all the tested compounds, DAs and PIs, showed moderate to good
inhibition. The antibacterial activity seemed to be dependent on the heterocyclic moiety
as well as on the nature of substituent. The imidazole containing compounds are
antibacterial active, and this activity can be further enhanced by the presence of electron
withdrawing groups on the imidazole moiety [48]. The polymers DAb and PIb containing
–
CF
strong electronegativity of F atom and the high polarity of -CF
indicated that electrondonating groups such as -NH decreased the antibacterial effect of
the imidazole-containing compounds. Also, PIa and PIb had good inhibitory effect
3
groups have shown good activity against all tested bacteria which can be due to the
3
group. The results also
2
1
2

against the tested bacteria due to the presence of imidazole moieties and were comparable
with antibiotic tetracycline.
2
.7. Adsorption of heavy metal ions
In these polymers, the presence of imidazole rings and ether linkages in the backbone can
act as proper hosts for the adsorption and formation of complex with the target metal
ions. 5 mg PIa2 and PIb2 was added to the separate 25 mL metal ion solution with initial
-1
concentration of 10 mg L . The solutions were stirred for 3 days at room temperature.
After separation by centrifuge, the amount of adsorbed ions was calculated using
equations given in the experimental section and the respective adsorption data. As the
2
+
3+
2+
results were summarized in Table 5, the order for the adsorption was: Hg > Cr > Cd
2
+
2+
>
Co > Pb . It is observed that the adsorption order of metal ions by the polymers is
inversely proportional with the radius of metal ions. These results show that there might
be not enough large free space between the polymer chains in the solid state to
accommodate large radius metal ions. Also, the adsorption of metal ions by PIa was
higher than adsorption by PIb. This can be due to the strong electron withdrawing effect
of -CF groups and as a result of attractive force with the metal ions.
3
3
. Conclusions
Two series of novel polyimides were prepared from new diamines and commercially
available dianhydrides. These polymers had inherent viscosities ranging from 0.38 to
.66 dL/g and exhibited solubility in a wide range of organic solvents. The results
showed that presence of different functional groups such as ether linkage and bulky
0
1
3

groups such as -CF , substituted imidazole and xanthene in the polymers backbones
3
improve the solubility while maintaining thermal stability. The thermal stability of these
polymers were verified by measuring Tg (235-303 °C), temperature of 10% weight loss
°
(
402-498 C), and char yields (31-62 wt%). The antibacterial study of these polymers
showed that those containing electron withdrawing groups had higher activity against
gram-positive and gram negative bacteria. Therefore, these polymers containing
combination of different functional groups in their structures showed acceptable
properties of thermal, solubility, antibacterial, and metal ions adsorption and can be
suitable for varieties of applications.
4
. Experimental
4
.1. Materials
All chemicals were purchased from Fluka and Merck Chemical Co. (Germany)
through a local agency and were used as received without further purification. N-methyl-
-pyrrolidone (NMP), N,N-dimethylacetamide (DMAc), and pyridine (Py) were purified
2
by distillation under reduced pressure over calcium hydride and stored over 4 Å
molecular sieves. Dianhydrides such as pyromellitic dianhydride (PMDA), 3,3',4,4'-
benzophenone tetracarboxylic dianhydride (BTDA) and bicycle-[2.2.2]-oct-7-ene-2,3,5,6
°
tetracarboxylic dianhydride (BCDA) were dried in a vacuum oven at 110 C for 5 h.
4
.2. Characterization
Proton nuclear magnetic resonance ( H NMR) spectra were recorded on a 400 MHz
Bruker Avance DRX (Germany) instrument using DMSO-d as solvent and tetramethyl
1
6
1
4

silane as an internal standard. Proton resonances are designated as singlet (s), doublet (d),
and multiplet (m). FT-IR spectra were recorded using a Bruker Tensor 27 spectrometer
-
1
on KBr pellets over the range of 400-4000 cm . Elemental analyses performed by a
CHN-600 Leco elemental analyzer. Melting point (uncorrected) was measured with a
Barnstead Electrothermal engineering LTD 9200 apparatus. Inherent viscosities (at a
concentration of 0.5 g/dL) were measured with an Ubbelohde suspended-level viscometer
°
at 25 C using NMP as solvent. Quantitative solubility was determined using 0.05 g of the
polymer in 0.5 mL of solvent. Thermogravimetric analysis (TGA) was performed with
the DuPont Instruments (TGA 951) analyzer well equipped with a PC at a heating rate of
°
3
1
8
0 C/min under nitrogen atmosphere (20 cm /min) and in the temperature range of 30-
°
00 C. Calorimetry curves were recorded on a Perkin Elmer pyris 6 DSC under nitrogen
3
°
atmosphere (20 cm /min) at a heating rate of 10 C/min. Glass-transition temperatures
g
(T ) values were read at the middle of the transition in heat capacity and were taken from
°
°
-1
the second heating scan after cooling from 350 C at a cooling rate of 20 Cmin .
Ultraviolet-visible and fluorescence emission spectra were recorded on a Cecil 5503
(Cecil Instruments, Cambridge, UK) and Perkin-Elmer LS-3B spectrophotometers
(Norwalk, CT, USA) (slit width= 2 nm), respectively, using a dilute polymer solution
(0.20 g/dL) in NMP. The metal ion concentrations in the supernatants were determined
using atomic absorption spectrophotometer (BRAICWFX-130 AA). PIs films were
prepared by dissolving 0.5 g PI in 5 mL NMP and the homogeneous solution was poured
°
°
into a 9 cm-diameter glass culture dish, heated under vacuum at 50 C for 2 h, 100 C for
°
5
h, and 150 C for 3 h to evaporate the solvent slowly. Polymer films were self-stripped
°
off from the glass surface by soaking in water and then dried in a vacuum oven at 170 C
1
5

for 10 h. To determine water uptake of the polymers, the dried films were immersed in
°
deionized water at 25 C. After 24 h, the films were removed from water and then they
were quickly placed between sheets of filter paper to remove the excess water and films
were weighed immediately.
4
.3. Antibacterial assay
The antibacterial activities of the synthesized compounds were tested onto LB
-1
(
Luria-Bertani) medium. The LB medium included: BactoTM tryptone, 10.0 g L ; yeast
-1
-1
-1
extract, 5.0 g L ; sodium chloride, 5.0 g L ; and glucose, 1.0 g L . The medium was
°
dispensed into universal bottles and sterilized at 121 C for 15 min. 0.04 g of diamines
and PI1(a,b) were dissolved separately in 20 mL DMSO to produce 2 mg/mL solutions
which were filter sterilized using a 0.22 μm Ministart (Sartorius). The sterilized solutions
were added into LB medium to give a final concentration of 1-300 µg/mL as required.
The antibacterial activities of the compounds were compared with known antibiotic
tetracycline at the same concentration. The minimum inhibitory concentration (MIC) test
of the newly synthesized compounds were determined in vitro against microorganisms
including the two Gram-positive bacteria Staphylococcus aureus ATCC 25923 and
Bacillus subtilis PTCC 1156 and two Gram-negative bacteria Escherichia coli PTCC1533
and Pseudomonas aeruginosa PTCC 1707. 1% (v/v) inoculums of each culture was
inoculated into the LB medium containing different concentrations of the synthesized
°
compounds and incubated on the orbital shaker at 37 C and 100 rpm. Before using the
cultures, they were standardized with a final cell density of approximately 108 cfu mL-
1
6

1.
The synthesized compounds sensitivity of the strains were determined for positive or
negative growth after 24h.
4
.4. Adsorption studies
For solid-liquid extraction of Cr , Pb , Hg , Cd and Co , 5 mg of the appropriate
polymer powder was shaken with 25 mL of aqueous solution of the metal salt with initial
3
+
2+
2+
2+
2+
-1
°
concentration of 10 mg L for 3 days at 25 C and pH 7-8. After centrifugal separation,
the metal ion concentrations in the supernatants were determined by atomic absorption
spectrophotometer. The removal percentage (R%) of each metal ion and the adsorption
-1
capacity that represents the amount of adsorbed ions (mg g ) were calculated using the
following equations, respectively:
(
%) R= [(C
= [(C -C
where C and C
aqueous phase after adsorption, respectively (mg L ), Q
o
-C
A
)/C
o
]×100
(1)
Q
t
o
A
)]×V/W
(2)
0
A
are the concentrations of metal ions in the initial solution and in the
-1
t
is the amount of metal ions
adsorbed into the unit of the composites (mg g ), V is the volume of the aqueous phase
mL) and W is the weight of the polymer (g).
-1
(
4
.5. Monomer synthesis
The following synthetic methods led to the synthesis of target diamines are also
outlined in Scheme 1.
.5.1. Synthesis of 4,4'-dihydroxybenzil
4
1
7

Into a 100 mL round-bottomed two-necked flask equipped with a magnetic stir bar
and a reflux condenser, 4,4'-dimethoxy benzil (2 g, 0.0075 mol), aqueous HBr (15 mL,
4
2
8%) and glacial acetic acid (15 mL) were placed. The reaction mixture was refluxed for
4 h, and then poured in 100 mL water after cooling to room temperature. Ethyl acetate
was added to the mixture to give two phases of which the organic phase containing the
product was separated and dried over magnesium sulfate for 12 h. The solvent was
removed under reduced pressure and the obtained yellow precipitate was washed
°
thoroughly with water and then dried in a vacuum oven at 80 C. Yield: 94% (1.7 g), and
°
-1
melting point: 229-231 C. FT-IR (KBr) at cm : 3400 (OH phenol), 3045 (C-H aromatic),
1
1
4
4
646 (C=O), 1576 (C=C), 1223 (C-O). H NMR (400 MHz, DMSO-d
6
,): δ 6.91-6.95 (d,
H, J= 8.0 Hz), 7.73-7.77 (d, 4H, J= 8.0 Hz), 10.84 (s, 2H).
.5.2. Synthesis of 4-(14H-dibenzo[a,j]xanthen-14-yl)benzaldehyde (1)
Into a 100 mL round-bottomed two-necked flask equipped with a condenser and a
magnetic stir bar, a mixture of 2-naphthol (1.44 g, 0.01 mol), terephthalaldehyde (0.67 g,
0
.005 mol), and p-toluenesulfonic acid as catalyst were added. The mixture was stirred
°
for 2 h in CHCl
3
at 60-65 C. After completion of the reaction (as indicated by TLC), the
reaction mixture was poured into the ice water and the solid was collected by filtration,
washed with water and then dried. The obtained solid was recrystallised from hot ethanol
°
°
and dried in a vacuum oven at 80 C. Yield: 95% (1.83 g), and melting point: 310-312 C.
-1
FT-IR (KBr) at cm : 3060 (aromatic C-H); 2929 (aliphatic C-H); 2738 (aldehyde C-
1
H); 1690 (C=O); 1591 (C=C); 1251 (C-O-C). H NMR (400 MHz, DMSO-d
6
,): δ 6.85 (s,
1
H, CH), 7.46 (t, 2H, Ar-H, J= 8.0 Hz), 7.58 (d, 2H, Ar-H, J= 8.0 Hz), 7.63 (t, 2H, Ar-H,
J= 8.0 Hz), 7.68 (d, 2H, Ar-H, J= 8.0 Hz), 7.87 (d, 2H, Ar-H, J= 8.0 Hz), 7.94 (t, 4H,
1
8

1
Ar-H, J= 8.0 Hz), 8.68 (d, 2H, Ar-H, J= 8.0 Hz), 9.75 (s, 1H, C-H aldehyde) (For the H
NMR spectrum, see Fig. S1 in Supporting Information). Anal. Calcd. for C28
g/mol): C, 87.05%; H, 4.66%. Found: C, 87.01%; H, 4.73%.
H
18
2
O (386
4
.5.3. Synthesis of 1,2-bis(4-(4-nitrophenoxy)phenyl)ethane-1,2-dione (2a)
Into a 100 mL round-bottomed two-necked flask equipped with a magnetic stir bar
and a reflux condenser, 4,4'-dihydroxybenzil (1.21 g, 0.005 mol) and 4-
fluoronitrobenzene (1.41 g, 0.01 mol) were dissolved in 10 mL DMSO, and then
potassium carbonate (1.38 g, 0.01 mol) was added and the mixture was stirred for 30 min
at room temperature. The reaction mixture was heated at 110 ºC for 6 h and then poured
in 100 mL water. The yellow precipitate was filtered off and dried in a vacuum oven at
°
°
8
0 C. Yield: 91% (2.2 g), and melting point: 150-153 C.
-1
FT-IR (KBr) at cm : 3070 (aromatic C-H); 1690 (C=O); 1585 (C=C); 1532, 1342
1
(
NO
2
); 1241 (C-O) stretching. H NMR (400 MHz, DMSO-d
6
,): δ 7.34 (d, 8H, Ar-H, J=
1
8
.0 Hz), 8.04 (d, 4H, Ar-H, J= 8.0 Hz), 8.31 (d, 4H, Ar-H, J= 8.0 Hz) (For the H NMR
spectrum, see Fig. S2 in Supporting Information). Anal. Calcd. for C26
g/mol): C, 64.46%; H, 3.31%; N, 5.79%. Found: C, 64.41%; H, 3.40%; N, 5.77%.
.5.4. Synthesis of 1,2-bis(4-(4-nitro-2-(trifluoromethyl)phenoxy)phenyl)ethane-1,2-dione
2b)
Into a 100 mL round-bottomed two-necked flask equipped with a magnetic stir bar
and a reflux condenser, 4,4'-dihydroxybenzil (1.21 g, 0.005 mol) and 1-chloro-4-nitro-2-
trifluoromethyl) benzene (2.25 g, 0.01 mol) were dissolved in 10 mL DMSO, then
H
16
N
2
8
O (484
4
(
(
potassium carbonate (1.38 g, 0.01 mol) was added and the mixture was stirred for 30 min
at room temperature. The reaction mixture was heated at 110 ºC for 6 h and then poured
1
9

in 100 mL water. The yellow precipitate was filtered off and dried in a vacuum oven at
°
°
8
0 C. Yield: 93% (2.9 g), and melting point: 157-160 C.
-1
FT-IR (KBr) at cm : 3074 (aromatic C-H); 1695 (C=O); 1586 (C=C); 1534, 1353
1
(
NO
2
); 1268 (C-O) stretching. H NMR (400 MHz, DMSO-d
6
,): δ 7.41 (d, 4H, Ar-H, J=
8
.0 Hz), 7.46 (d, 2H, Ar-H, J= 8.0 Hz), 8.08 (d, 4H, Ar-H, J= 8.0 Hz), 8.54 (dd, 2H, Ar-
1
H, J= 8.0 Hz), 8.57 (d, 2H, Ar-H, J= 2.8 Hz) (For the H NMR spectrum, see Fig. S3 in
Supporting Information). Anal. Calcd. for C28
H
14
F
6
N
2
8
O (620 g/mol): C, 54.19%; H,
2
.26%; N, 4.52%. Found: C, 54.15%; H, 2.32%; N, 4.48%.
.5.5. Synthesis of 2-(4-(14H-dibenzo[a,j]xanthen-14-yl)phenyl)-4,5-bis(4-(4-
4
nitrophenoxy)phenyl)-1H-imidazole (DNa)
Into a 100 mL round-bottomed two-necked flask equipped with a condenser, a
magnetic stir bar and a nitrogen gas inlet tube, a mixture of compound 1 (1.93 g, 0.005
mol), compound 2a (2.42 g, 0.005 mol), ammonium acetate (2.7 g, 0.035 mol), and
glacial acetic acid (25 mL) was refluxed for 14 h. Upon cooling, the yellow precipitate
was collected by filtration, washed with a mixture of C
2
H
5
OH/H
2
O (50/50, v/v), and
°
°
dried in a vacuum oven at 80 C. Yield: 93% (3.95 g), and melting point: 205-207 C.
-1
FT-IR (KBr) at cm : 3351 (NH, imidazole ring); 3068 (aromatic C-H); 2927
1
(
aliphatic C-H); 1590 (C=C); 1546, 1340 (NO
DMSO-d
Hz), 7.46 (t, 2H, Ar-H, J= 8.0 Hz), 7.56 (d, 4H, Ar-H, J= 8.0 Hz), 7.58 (d, 2H, Ar-H, J=
.0 Hz), 7.63 (t, 2H, Ar-H, J= 8.0 Hz), 7.70 (d, 2H, Ar-H, J= 8.0 Hz), 7.87 (d, 2H, Ar-H,
2
); 1243 (C-O-C). H NMR (400 MHz,
6
,): δ 6.74 (s, 1H, CH), 7.11 (d, 4H, Ar-H, J= 8.0 Hz), 7.13 (d, 4H, Ar-H, J= 8.0
8
J= 8.0 Hz), 7.93 (d, 4H, Ar-H, J= 8.0 Hz), 8.22 (d, 4H, Ar-H, J= 8.0 Hz), 8.69 (d, 2H,
1
Ar-H, J= 8.0 Hz), 12.97 (s, 1H, N-H imidazole ring) (For the H NMR spectrum, see Fig.
2
0

S4 in Supporting Information). Anal. Calcd. for C54
H
34
N
4
7
O (850 g/mol): C, 76.23%; H,
4
.00%; N, 6.59%. Found: C, 76.18%; H, 4.10%; N, 6.56%.
.5.6. Synthesis of 2-(4-(14H-dibenzo[a,j]xanthen-14-yl)phenyl)-4,5-bis(4-(4-nitro-2-
4
(trifluoromethyl)phenoxy)phenyl)-1H-imidazole (DNb)
In a 100 mL round-bottomed two-necked flask equipped with a condenser, a
magnetic stir bar and a nitrogen gas inlet tube, a mixture of compound 1 (1.93 g, 0.005
mol), compound 2b (3.1 g, 0.005 mol), ammonium acetate (2.7 g, 0.035 mol), and glacial
acetic acid (25 mL) was refluxed for 14 h. Upon cooling, the yellow precipitate was
collected by filtration, washed with a mixture of C
2
H
5
OH/H
2
O (50/50, v/v), and dried in a
°
°
vacuum oven at 80 C. Yield: 95% (4.68 g), and melting point: 209-211 C.
-1
FT-IR (KBr) at cm : 3390 (NH, imidazole ring); 3064 (aromatic C-H); 2929
1
(
aliphatic C-H); 1590 (C=C); 1536, 1340 (NO
DMSO-d
.0 Hz), 7.29 (d, 2H, Ar-H, J= 8.0 Hz), 7.47 (t, 2H, Ar-H, J= 8.0 Hz), 7.58 (d, 4H, Ar-H,
2
); 1246 (C-O-C). H NMR (400 MHz,
6
,): δ 6.78 (s, 1H, CH), 7.11 (dd, 2H, Ar-H, J= 8.0 Hz), 7.16 (d, 2H, Ar-H, J=
8
J= 8.0 Hz), 7.65 (d, 2H, Ar-H, J= 8.0 Hz), 7.75 (d, 2H, Ar-H, J= 8.0 Hz), 7.84 (d, 2H,
Ar-H, J= 8.0 Hz), 7.95 (d, 4H, Ar-H, J= 8.0 Hz), 8.40 (dd, 2H, Ar-H, J= 8.0 Hz), 8.48
(d, 2H, Ar-H, J= 2.8 Hz), 8.51 (dd, 2H, Ar-H, J= 8.0 Hz), 8.71 (d, 2H, Ar-H, J= 8.0 Hz),
1
1
2.58 (s, 1H, N-H imidazole ring) (For the H NMR spectrum, see Fig. S5 in Supporting
Information). Anal. Calcd. for C56
H
32
F
6
N
4
7
O (986 g/mol): C, 68.15%; H, 3.25%; N,
5
.68%. Found: C, 68.10%; H, 3.33%; N, 5.65%.
.5.7. Synthesis of 2-(4-(14H-dibenzo[a,j]xanthen-14-yl)phenyl)-4,5-bis(4-(4-
4
aminophenoxy)phenyl)-1H-imidazole (DAa)
2
1

In a 100 mL round-bottomed two-necked flask equipped with a magnetic stir bar, a
mixture of compound DNa (4.25 g, 0.005 mol) and Pd/C (0.1 g, 10%) was dispersed in
5
0 mL ethanol. The suspension was heated to reflux, and then 6 mL hydrazine
monohydrate was added slowly to the mixture. After a further 8 h of reflux, the solution
was filtered hot to remove Pd/C, and the filtrate was cooled until white crystals were
°
formed. The product was collected by filtration and dried in a vacuum oven at 80 C.
°
Yield: 88% (3.48 g), and melting point: 179-182 C.
-1
FT-IR (KBr) at cm : 3453 (N-H imidazole ring); 3382, 3372 (NH ); 3048 (C-H
2
1
aromatic); 2916 (aliphatic C-H); 1616 (C=N); 1582 (C=C); 1236 (C-O-C). H NMR (400
MHz, DMSO-d ,): δ 4.99 (s, 4H, NH ), 6.60 (d, 4H, Ar-H, J= 8.0 Hz), 6.75 (s, 1H, CH),
.79 (d, 4H, Ar-H, Ar-H, J= 8.0 Hz), 6.86 (d, 4H, Ar-H, Ar-H, J= 8.0 Hz), 7.32 (d, 2H,
Ar-H, J= 8.0 Hz), 7.37 (d, 2H, Ar-H, J= 8.0 Hz), 7.46 (t, 2H, Ar-H, J= 8.0 Hz), 7.58 (d,
H, Ar-H, J= 8.0 Hz), 7.65 (t, 2H, Ar-H, J= 8.0 Hz), 7.70 (d, 2H, Ar-H, J= 8.0 Hz), 7.78
6
2
6
2
(d, 2H, Ar-H, J= 8.0 Hz), 7.95 (d, 4H, Ar-H, J= 8.0 Hz), 8.70 (d, 2H, Ar-H, J= 8.0 Hz),
1
1
2.30 (s, 1H, N-H imidazole ring) (For the H NMR spectrum, see Fig. S6 in Supporting
Information).
Anal. Calcd. for C54
H N
38 4
3
O (790 g/mol): C, 82.02%; H, 4.81%; N, 7.09%. Found: C,
8
1.98%; H, 4.87%; N, 7.08%.
.5.8. Synthesis of 2-(4-(14H-dibenzo[a,j]xanthen-14-yl)phenyl)-4,5-bis(4-(4-amino-2-
4
(trifluoromethyl)phenoxy)phenyl)-1H-imidazole (DAb)
In a 100 mL round-bottomed two-necked flask equipped with a magnetic stir bar, a
mixture of compound DNb (4.93 g, 0.005 mol) and Pd/C (0.1 g, 10%) was dispersed in
0 mL ethanol. The suspension was heated to reflux, and then 6 mL hydrazine
5
2
2

monohydrate was added slowly to the mixture. After a further 8 h of reflux, the solution
was filtered hot to remove Pd/C, and the filtrate was cooled until white crystals were
°
formed. The product was collected by filtration and dried in a vacuum oven at 80 C.
°
Yield: 86% (3.98 g), and melting point: 171-173 C.
-1
FT-IR (KBr) at cm : 3462 (N-H imidazole ring), 3396, 3376 (NH ), 3058 (C-H
2
1
aromatic); 2921 (aliphatic C-H); 1625 (C=N); 1596 (C=C); 1238 (C-O-C). H NMR (400
MHz, DMSO-d ,): δ 5.44 (s, 2H, NH ), 5.50 (s, 2H, NH ), 6.76 (d, 2H, Ar-H, J= 2.0 Hz),
.79 (s, 1H, CH), 6.83 (d, 2H, Ar-H, J= 8.0 Hz), 6.87 (d, 4H, Ar-H, J= 8.0 Hz), 6.92 (dd,
H, Ar-H, J = 8.0 Hz and J = 2.0 Hz), 7.36 (d, 2H, Ar-H, J= 8.0 Hz), 7.41 (d, 2H, Ar-H,
6
2
2
6
2
1
2
J= 8.0 Hz), 7.46 (t, 2H, Ar-H, J= 8.0 Hz), 7.58 (d, 2H, Ar-H, J= 8.0 Hz), 7.64 (t, 2H, Ar-
H, J= 8.0 Hz), 7.71 (d, 2H, Ar-H, J= 8.0 Hz), 7.79 (d, 2H, Ar-H, J= 8.0 Hz), 7.94 (d, 4H,
Ar-H, J= 8.0 Hz), 8.70 (d, 2H, Ar-H, J= 8.0 Hz), 12.35 (s, 1H, N-H imidazole ring).
Anal. Calcd. for C56
H
36
F
6
N
4
3
O (926 g/mol): C, 72.57%; H, 3.89%; N, 6.05%. Found: C,
7
2.52%; H, 3.94%; N, 6.06%.
.6. Polymer synthesis
The following general procedure was used for the preparation of two series of PIs
4
from the prepared diamines DAa and Dab with aliphatic and aromatic commercial
dianhydrides. A 100 mL three-necked round-bottomed flask equipped with a condenser,
a magnetic stir bar, a nitrogen gas inlet tube, and a calcium chloride drying tube was
charged with 1 mmol diamine and 10 mL dry NMP. This mixture was stirred at room
temperature for 0.5 h, then 1 mmol dried dianhydride was added and stirred at room
temperature for 24 h to obtain a viscous solution of poly(amic acid) (PAA) in NMP. The
chemical imidization of PAA was carried out by adding 3 mL of a mixture of acetic
2
3

anhydride/pyridine (6/4, V/V) into the solution while stirring at room temperature for 1 h.
°
The mixture was then stirred at 130 C for 12 h to yield a homogeneous polymer solution,
which was poured slowly into methanol to give a precipitate that was collected by
filtration, washed thoroughly with hot water, and then was further purified by washing
with refluxing methanol for 24 h in a Soxhlet apparatus to remove the low molecular
weight oligomers. The yields were in the range of 85%-92%. The inherent viscosities of
°
the polymers measured at a concentration of 0.5 g/dL in NMP (at 25 C) were in the
range of 0.38-0.66 dL/g.
-
1
4
.6.1. PIa1: Yield = 90%, and ηinh (dL/g) = 0.46. FT-IR (KBr) at cm : 3421 (N-H
imidazole ring); 3037 (aromatic C-H); 2931 (aliphatic C-H); 1783 and 1720 (C=O
1
imide); 1594 (C=N); 1509 (C=C); 1377 (C-N); 1242 (C-O-C). H NMR (400 MHz,
DMSO-d
ring). Anal. Calcd. for (C64
Found: C, 78.99%; H, 3.76%; N, 5.74%.
.6.2. PIb1: Yield = 92%, and ηinh (dL/g)= 0.52. FT-IR (KBr) at cm : 3420 (N-H
6
): δ 6.76 (s, 1H, CH), 6.91-8.71 (m, 34H, Ar-H), 12.49 (s, 1H, N-H, imidazole
H
36
N
4
O )
7 n
(972 g/mol): C, 79.01%; H, 3.70%; N, 5.76%.
-1
4
imidazole ring); 3042 (aromatic C-H); 2937 (aliphatic C-H); 1782 and 1722 (C=O
1
imide); 1597 (C=N); 1512 (C=C); 1378 (C-N); 1245 (C-O-C). H NMR (400 MHz,
DMSO-d
ring). Anal. Calcd. for (C66
Found: C, 71.39%; H, 3.12%; N, 5.06%.
.6.3. PIa2: Yield = 89%, and ηinh (dL/g)= 0.61. FT-IR (KBr) at cm : 3392 (N-H
6
): δ 6.77 (s, 1H, CH), 7.93-8.72 (m, 32H, Ar-H), 12.50 (s, 1H, N-H, imidazole
H
34
F
6
N
4
O )
7 n
(1108 g/mol): C, 71.48%; H, 3.07%; N, 5.05%.
-1
4
imidazole ring); 3060 (aromatic C-H); 2924 (aliphatic C-H); 1778 and 1722 (C=O
1
imide); 1598 (C=N); 1501 (C=C); 1376 (C-N); 1241 (C-O-C). H NMR (400 MHz,
2
4

DMSO-d
ring). Anal. Calcd. for (C71
Found: C, 79.11%; H, 3.77%; N, 5.22%.
.6.4. PIb2: Yield = 92%, and ηinh (dL/g)= 0.66. FT-IR (KBr) at cm : 3416 (N-H
6
): δ 6.76 (s, 1H, CH), 6.99-8.71 (m, 38H, Ar-H), 12.42 (s, 1H, N-H, imidazole
H
40
N
4
O )
8 n
(1076 g/mol): C, 79.18%; H, 3.72%; N, 5.20%.
-1
4
imidazole ring); 3063 (aromatic C-H); 2926 (aliphatic C-H); 1781 and 1727 (C=O
1
imide); 1607 (C=N); 1494 (C=C); 1376 (C-N); 1245 (C-O-C). H NMR (400 MHz,
DMSO-d
ring). Anal. Calcd. for (C73
Found: C, 72.19%; H, 3.18%; N, 4.64%.
.6.5. PIa3: Yield = 87%, and ηinh (dL/g)= 0.38. FT-IR (KBr) at cm : 3407 (N-H
6
): δ 6.77 (s, 1H, CH), 6.99-8.72 (m, 36H, Ar-H), 12.50 (s, 1H, N-H, imidazole
H
38
F
6
N
4
O )
8 n
(1212 g/mol): C, 72.28%; H, 3.14%; N, 4.62%.
-1
4
imidazole ring); 3058 (aromatic C-H); 2922 (aliphatic C-H); 1778 and 1719 (C=O
1
imide); 1608 (C=N); 1501 (C=C); 1380 (C-N); 1241 (C-O-C). H NMR (400 MHz,
DMSO-d
.87-8.68 (m, 32H, Ar-H), 12.42 (s, 1H, N-H, imidazole ring). Anal. Calcd. for
(1002 g/mol): C, 79.04%; H, 4.19%; N, 5.59%. Found: C, 78.98%; H,
.26%; N, 5.57%.
.6.6. PIb3: Yield = 85%, and ηinh (dL/g)= 0.42. FT-IR (KBr) at cm : 3420 (N-H
6
): δ 2.18 (m, 2H, CH), 2.57 (m, 2H, CH), 6.33 (m, 2H, CH) 6.74 (s, 1H, CH),
6
(C
66
H
42
N
4
O )
7 n
4
4
-1
imidazole ring); 3064 (aromatic C-H); 2919 (aliphatic C-H); 1779 and 1714 (C=O
1
imide); 1611 (C=N); 1505 (C=C); 1381 (C-N); 1244 (C-O-C). H NMR (400 MHz,
DMSO-d
.91-8.72 (m, 30H, Ar-H), 12.43 (s, 1H, N-H, imidazole ring). Anal. Calcd. for
(1138 g/mol): C, 71.70%; H, 3.51%; N, 4.92%. Found: C, 71.61%; H,
.61%; N, 4.91%.
6
,): δ 2.20 (m, 2H, CH), 2.65 (m, 2H, CH), 6.35(m, 2H, CH) 6.76 (s, 1H, CH),
6
(C
68
H
40
F
6
N
4
O )
7 n
3
2
5

Acknowledgments
We wish to express our gratitude to the Research Affairs Division of University of
Kurdistan (UOK), Sanandaj (Iran), for partial financial support.
References
[
[
1] P.E. Cassidy, Thermally stable polymers. Marcel Dekker, New York, 1980.
2] D. Wilson, H.D. Stenzenberger, P.M. Hergenrother, Polyimides. Chapman and Hall,
New York, 1990.
[
3] M.K. Ghosh, K.L. Mittal, Polyimides fundamentals and applications. Marcel Decker,
New York, 1996.
[
[
[
[
[
[
[
4] M. Ree, Macromol. Res. 14 (2006) 1-33.
5] Y.J. Cho, H.B. Park, Macromol. Rapid. Comm. 32 (2011) 579-586.
6] D. X. Yin, Y.F. Li, H.X. Yang, S.Y. Yang, Polymer 46 (2005) 3119-3127.
7] G. Maier, Prog. Polym. Sci. 26 (2001) 3-65.
8] S.H. Hsiao, T.L. Huang, J. Polym. Res. 11 (2004) 9-21.
9] S. Zhang, Y. Li, D. Yin, Eur. Polym. J. 41 (2005) 1097-1107.
10] A.H. Frazer, High temperature resistant polymers. New York: Wiley Inter Science,
1
968.
[
11] A.T. Vaganova, I.K. Shundrina, S.Z. Kusov, E.V. Karpova, I.Y. Bagryanskaya, E.V.
Malykhin, J. Fluorine Chem. 135 (2012) 129-136.
2
6

[
[
12] S.Z. Zhu, J.W. Zhao, Y.X. Zhang, J. Fluorine Chem. 123 (2003) 221-225.
13] Q. Jin, T. Yamashita, K. Horie, R. Yokota, I. Mita, J. Polym. Sci. Part A: Polym.
Chem. 31 (1993) 2345-2351.
[
[
[
14] I.K. Shundrina, T.A. Vaganova, S.Z. Kusov, V.I. Rodionov, E.V. Karpova, E.V.
Malykhin, J. Fluorine Chem. 132 (2011) 207-215.
15] M. Yamada, M. Kusama, T. Matsumoto, T. Kurosaki, Macromolecules 26 (1993)
4
961-4963.
16] S. Chen, Y. Yin, H. Kita, K.I. Okamoto, J. Polym. Sci. Part A: Polym. Chem. 45
2007) 2797-2811.
(
[
[
17] Y. Tsuda, M. Kojima, T. Matsuda, J.M. Oh, Polym. J. 40, (2008) 354-366.
18] D. Yin, Y. Li, Y. Shao, X. Zhao, S. Yang, L. Fan, J. Fluorine Chem. 126 (2005) 819-
8
23.
[
[
19] J. G. Liu, Y. Nakamura, Y. Shibasaki, S. Ando, Polym. J. 39 (2007) 543-550.
20] Y. Shao, Y. Li, X. Zhao, T. Ma, C. Gong, F. Yang, Eur. Polym. J. 43 (2007) 4389-
4
397.
[
21] I.K. Shundrina, T.A. Vaganova, S.Z. Kusov, V.I. Rodionov, E.V. Karpova,V.V.
Koval, Y.V. Gerasimova, E.V. Malykhin, J. Fluorine Chem. 130 (2009) 733-741.
22] M. Ghaemy, R. Alizadeh, Eur. Polym. J. 45 (2009) 1681-1688.
[
[
23] Y.C. Kung, G.S. Liou, S.H. Hsiao, J. Polym. Sci., Part A: Polym. Chem. 47 (2009)
1
740-1755.
[
[
24] Q. Zhang, S. Li, W. Li, S. Zhang, Polymer 48 (2007) 6246-6253.
25] M. Taghavi, M. Ghaemy, M. Hassanzadeh, S. M. Amini Nasab, Chinese. J. Polym.
Sci. 31 (2013) 679-690.
2
7

[
26] D.D. Guo, J.W. Jiang, Y.J. Liu, X.L. Liu, S.R. Sheng, J. Fluorine. Chem. 175 (2015)
69-175.
1
[
[
27] S.H. Hsiao, J.Y. Lin, J. Fluorine Chem. 178 (2015) 115-130.
28] A.I. Wozniak, A.S. Yegorov, V.S. Ivanov, S.M. Igumnov, K.V. Tcarkova, J.
Fluorine Chem. 180 (2015) 45-54.
[
[
[
29] X. Wanga, F. Liu, J. Lai, Z. Fu, X. You, J. Fluorine Chem. 164 (2014) 27-37.
30] F. Yang, Y. Li, T. Ma, Q. Bu, S. Zhang, J. Fluorine Chem. 131 (2010) 767-775.
31] T.A. Vaganova, I.K. Shundrina, S.Z. Kusov, V.I. Rodionov, E.V. Malykhin, J.
Fluorine Chem. 149 (2013) 57-64.
[
32] M. Ghaemy, S. Sharifi, S.M. Amini Nasab, M. Taghavi, J. Macromol. Sci., Pure
Appl. Chem. 50 (2013) 487-497.
[
33] M. Ghaemy, M. Hassanzadeh, M. Taghavi, S.M. Amini Nasab, J. Fluorine Chem.
42 (2012) 29-40.
34] T. Ma, S. Zhang, Y. Li, F. Yang, C. Gong, J. Zhao, J. Fluorine Chem. 131 (2010)
24-730.
1
[
7
[
[
35] M. Ghaemy, M. Bazzar, J. Appl. Polym. Sci. 116 (2010) 64-71
36] S.H. Hsiao, G.S. Liou, Y.C. Kung, H.Y. Pan, C.H. Kuo, Eur. Polym. J. 45 (2009)
2
234-2248
37] X.L.Wang, Y.F. Li, C.L. Gong, T. Ma, F.C. Yang, J. Fluorine Chem. 129 (2008) 56-
3.
[
6
[
[
[
38] C.Y. Wang, G. Li, J.M. Jiang, Polymer 50 (2009) 1709-1716.
39] M. Ghaemy, R. Alizadeh, Eur. Polym. J. 45 (2009) 1681-1688.
40] M. Ghaemy, R. Alizadeh, H. Behmadi, Eur. Polym. J. 45 (2009) 3108-3115.
2
8

[
41] M. Taghavi, M. Ghaemy, M. Hassanzadeh, High. Perform. Polym. 24 (2012) 305-
18.
3
[
[
42] W. Li, S. Li, Q. Zgang, S. Zhang, Macromolecules 40 (2007) 8205-8211.
43] M. Ghaemy, R. Alizadeh, F.H. Nasr, J. Akbari, High. Perform. Polym. (2012) 262-
2
73.
[
[
44] S.M. Amini Nasab, M. Ghaemy, J. Polym.Res. 18 (2011) 1575-1586.
45] M. Ghaemy, F. Rahimi Berenjestanaki, M. Bazzar, Des. Monomers Polym. 17
(2014) 101-110
[
[
[
46] M. Ghaemy, S.M. Amini Nasab, Polym. J. 42 (2010) 648-656.
47] E.B. Anderson, T.E. Long, Polymer. 51 (2010) 2447-2454.
48] M. Ghaemy, B. Aghakhani, M. Taghavi, S.M. Amini Nasab, M. Mohseni, React.
Funct. Polym. 73 (2013) 555-563.
[
[
[
[
[
[
49] A. Masoumi, M. Ghaemy, eXPRESS Polym. Lett. 8 (2014) 187-196.
50] M.V. Dinu, E.S. Dragan, React. Funct. Polym. 68 (2008) 1346-1354.
51] A.S. Ozcan, O. Gok, A. Ozcan, J. Hazard. Mater. 161 (2009) 499-509.
52] S.M. Amini Nasab, R. Alizadeh, M. Ghaemy, Polym. Sci. Ser. B, 54 (2012) 30-40.
53] G.S. Liou, C.W. Chang, Macromolecules 41 (2008) 1667-1674.
54] D.W. Van Krevelen, P.J. Hoftyzer, Properties of polymers. 4th ed. Amsterdam:
Elsevier Scientific Publishing, 2008.
2
9