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1.
A new monomer containing imide linkages, bis[4-(p-phenoxybenzoyl)-1,2-benzenedioyl]-N,N,N′,N′-4,4′-diaminodiphenyl ether (BPBDADPE), was prepared by the Friedel–Crafts reaction of bis(4-chloroformyl-1,2-benzenedioyl)-N,N,N′,N′-4,4′-diaminodiphenyl ether (BCBDADPE) with diphenyl ether (DPE). Novel poly(aryl ether ketone)s containing imide linkages
in the main chains (PEK-I) were synthesized by electrophilic Friedel–Crafts solution copolycondensation of terephthaloyl chloride
(TPC) with a mixture of DPE and BPBDADPE. The polymers were characterized by different physico-chemical techniques. The polymers
with 10–40 mol% BPBDADPE are semicrystalline and had increased T
gs over commercially available poly(ether ether ketone) (PEEK) and poly(ether ketone ketone) (PEKK) (70/30) due to the incorporation
of imide linkages in the main chains. The polymers IV and V with 30–40 mol% BPBDADPE had not only high T
gs of 182–183 °C, but also moderate T
ms of 341–343 °C, having good potential for melt processing and exhibited high thermal stability and good resistance to common
organic solvents. 相似文献
2.
1,5-Bis(4-trimellitimido)naphthalene (II) was prepared by the condensation reaction of 1,5-naphthalenediamine and trimellitic anhydride. A series of aromatic poly(amide-imide)s
(IV
a–o) was synthesized by the direct polycondensation of the diimide-diacid (II) and various aromatic diamines (III
a–o). The reaction utilized triphenyl phosphite and pyridine as condensing agents in the presence of calcium chloride in N-methyl-2-pyrrolidone (NMP). The inherent viscosities of the resulting poly(amide-imide)s were in the range of 0.55∼1.39 dL/g.
These polymers were generally soluble in polar solvents, such as N,N-dimethylacetamide (DMAc), NMP, N,N-dimethylformamide (DMF). Flexible and tough poly(amide-imide) films were obtained by casting from a DMAc solution and had
tensile strengths of 90∼145 MPa, elongations to break of 5∼13 %, and initial moduli of 2.29∼3.73 GPa. The glass transition
temperatures of some poly(amide-imide)s were recorded in the range of 206∼218 °C, and most of the polymers did not show discernible
glass transition on their DSC traces. The 10% weight loss temperatures were above 522 °C in nitrogen and above 474 °C in air
atmosphere. 相似文献
3.
Two diamine monomers, 4,4′-[sulfonylbis(1,4-phenyleneoxy)]dianiline (III
a
) and 4,4′-[sulfonylbis(2,6-dimethyl-l,4-phenyleneoxy)]dianiline (III
b
), were prepared by an aromatic nucleophilic substitution of 4,4′-sulfonyldiphenol (I
a
) and 4,4′-sulfonylbis(2,6-dimethylphenol) (I
b
) with p-chloronitrobenzene in the presence of potassium carbonate, followed by hydrazine catalytic reduction of the intermediate
dinitro compounds. The diamines III
a
and III
b
were used as monomers with various aromatic tetracarboxylic dianhydrides (IV
a–f
) to synthesize polyimides. The polymerization was conducted in two steps via the formation of a poly(amic acid) precursor
followed by thermal cyclodehydration. The poly(amic acid)s had inherent viscosities above 0.87 and up to 2.56 dL/g. Most poly(amic
acid)s could be coated and thermodehydrated into flexible and transparent polyimide films. The polyimides derived from the
dianhydrides containing-O-and-SO2-or-C(CF3)2-bridging groups between the phthalic anhydride units were soluble in some organic solvents such as N,N-dimethylacetamide (DMAc) and N,N-dimethylformamide (DMF). The glass transition temperatures (Tg) of the polyimides were in the range from 254 to 300 °C. The methyl-substituted polyimides exhibited slightly higher solubility
and higher Tg compared to the corresponding unsubstituted polyimides. Thermogravimetric analysis (TG) showed that the polyimides containing
methyl substitutents started to lose weight around 450 °C and the unsubstituted ones started to lose weight around 550 °C. 相似文献
4.
Barnali Dasgupta Suman Kumar Sen Samarendra Maji Shyambo Chatterjee Susanta Banerjee 《应用聚合物科学杂志》2009,112(6):3640-3651
A new indane containing unsymmetrical diamine monomer ( 3 ) was synthesized. This diamine monomer leads to a number of novel semifluorinated poly (ether imide)s when reacted with different commercially available dianhydrides like benzene‐1,2,4,5‐tetracarboxylic dianhydride (PMDA), benzophenone‐3,3′, 4,4′‐tetracarboxylic dianhydride (BTDA), 4,4′‐(hexafluoro‐isopropylidene)diphthalic anhydride (6FDA), 4,4′‐oxydiphthalic anhydride (ODPA), and 4,4′‐(4,4′‐Isopropylidenediphenoxy)bis(phthalic anhydride) (BPADA) by thermal imidization route. All the poly(ether imide)s showed excellent solubility in several organic solvents such as N‐methylpyrrolidone (NMP), N,N‐dimethylformamide (DMF), N,N‐dimethylacetamide (DMAc), tetrahydrofuran (THF), chloroform (CHCl3) and dichloromethane (DCM) at room temperature. These light yellow poly (ether imide)s showed very low water absorption (0.19–0.30%) and very good optical transparency. Wide angle X‐ray diffraction measurements revealed that these polymers were amorphous in nature. The polymers exhibited high thermal stability up to 526°C in nitrogen with 5% weight loss, and high glass transition temperature up to 265°C. The polymers exhibited high tensile strength up to 85 MPa, modulus up to 2.5 GPa and elongation at break up to 38%, depending on the exact polymer structure. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009 相似文献
5.
A series of polyamides and poly(amide-imide)s were prepared by the direct polycondensation of 4,4′-[sulfonylbis(1,4-phenyleneoxy)]dianiline
or 4,4′-[sulfonylbis(2,6-dimethyl-1,4-phenyleneoxy)]dianiline with aromatic dicarboxylic acids and phthalimide unit-bearing
dicarboxylic acids in a N-methyl-2-pyrrolidone (NMP) solution containing dissolved calcium chloride using triphenyl phosphite and pyridine as condensing
agents. The inherent viscosities of the resulting polymers were above 0.45 dL/g and up to 1.70 dL/g. Except for the polyamides
derived from terephthalic acid and 4,4′-biphenyldicarboxylic acid, all the other polyamides and all poly(amide-imide)s were
readily soluble in polar organic solvents such as NMP, N, N-dimethylacetamide (DMAc), N,N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), and m-cresol, and afforded transparent and tough films by solution-casting. Most of the polymers showed distinct glass transition
on their differential scanning calorimetry (DSC) traces and their glass transition temperatures (Tg) stayed between 140–264 °C. The methyl-substituted polymers showed higher Tgs than the corresponding unsubstituted counterparts. The results of the thermogravimetry analysis (TGA) revealed that all
the methyl-substituted polymers showed lower initial decomposition temperatures than the unsubstituted ones. 相似文献
6.
Shou‐Ri Sheng Wei Zhang Chun Lu Jiong Wan Xiao‐Ling Liu Cai‐Sheng Song 《应用聚合物科学杂志》2012,126(1):297-303
A series of new cardo poly(ether imide)s bearing flexible ether and bulky xanthene pendant groups was prepared from 9,9‐bis[4‐(4‐aminophenoxy)phenyl]xanthene with six commercially available aromatic tetracarboxylic dianhydrides in N,N‐dimethylacetamide (DMAc) via the poly(amic acid) precursors and subsequent thermal or chemical imidization. The intermediate poly(amic acid)s had inherent viscosities between 0.83 and 1.28 dL/g, could be cast from DMAc solutions and thermally converted into transparent, flexible, and tough poly(ether imide) films which were further characterized by X‐ray and mechanical analysis. All of the poly(ether imide)s were amorphous and their films exhibited tensile strengths of 89–108 MPa, elongations at break of 7–9%, and initial moduli of 2.12–2.65 GPa. Three poly(ether imide)s derived from 4,4′‐oxydiphthalic anhydride, 4,4′‐sulfonyldiphthalic anhydride, and 2,2‐bis(3,4‐dicarboxyphenyl))hexafluoropropane anhydride, respectively, exhibited excellent solubility in various solvents such as DMAc, N,N‐dimethylformamide, N‐methyl‐2‐pyrrolidinone, pyridine, and even in tetrahydrofuran at room temperature. The resulting poly(ether imide)s with glass transition temperatures between 286 and 335°C had initial decomposition temperatures above 500°C, 10% weight loss temperatures ranging from 551 to 575°C in nitrogen and 547 to 570°C in air, and char yields of 53–64% at 800°C in nitrogen. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012 相似文献
7.
Summary N,N′-(3,3′,4,4′-benzophenonetetracarboxylic)-3,3′,4,4′-diimido-di-L-methionine (3) was prepared from the reaction of 3,3′,4,4′-benzophenonetetracarboxylic-3,3′,4,4′-dianhydride (1) with L-methionine (2) in a solution of (glacial acetic acid/pyridine) at refluxing temperature. The phosphorylation polycondensation of the diimide-diacid
monomer (3) with 1,3-phenylenediamine (4a), 1,4-phenylenediamine (4b), 2,6-diaminopyridine (4c), 3,5-diaminopyridine (4d), 4,4′-diaminobiphenyl (4e) and 4,4′-diaminodiphenylsulfone (4f) was carried out in N-methyl-2-pyrolidone (NMP). The resulting poly (amide-imide)s showed admirable moderate inherent viscosities (0.23–0.48 dl
g-1), good thermal stability and improved optical activity. All of the above compounds were fully characterized by IR spectroscopy,
elemental analysis and specific rotation. Some structural characterization and physical properties of these new poly (amide-imide)s
are presented. 相似文献
8.
A new series of N,N′-(bicyclo[2,2,2]oct-7-ene-tetracarboxylic)-bis-L-amino acids 3a–g were synthesized by the condensation reaction of bicyclo[2,2,2]oct-7-ene-2,3,5,6-tetracarboxylic dianhydride 1 with two equimolars of various amino acids such as L-alanine 2a, L-valine 2b, L-leucine 2c, L-isoleucine 2d, L-phenyl alanine 2e, L-2-aminobutyric acid 2f and L-histidine 2g in an acetic acid solution. Also 1,5-bis(4-aminophenyl)penta-1,4-dien-3-one 7 was synthesized by using a two-step reaction. At first 1,5-bis(4-nitrophenyl)penta-1,4-dien-3-one 6 was prepared from the reaction of two equimolars 4-nitrobenzaldehyde 5 and one equimolar acetone 4 in ethanol and NaHCO3 and dinitro compound 6 was reduced by using Na2S. Then seven new photosensitive and optically active organo-soluble poly(amide–imide)s (PAIs) 8a–g with good inherent viscosities were synthesized from the direct polycondensation reaction of new N,N′-(bicyclo[2,2,2]oct-7-ene-tetracarboxylic)-bis-L-amino
acids 3a–g with 1,5-bis(4-aminophenyl)penta-1,4-dien-3-one 7 by two different methods such as direct polycondensation in a medium consisting of N-methyl-2-pyrrolidone (NMP)/triphenyl
phosphite (TPP)/calcium chloride (CaCl2)/pyridine (py) and direct polycondensation in a tosyl chloride (TsCl)/pyridine (py)/N,N-dimethylformamide (DMF) system. The
polymerization reactions produced a series of photosensitive and optically active organo-soluble PAIs with high yield and
good inherent viscosity. The resulted polymers were fully characterized by means of FTIR and 1H-NMR spectroscopy, elemental analyses, inherent viscosity, specific rotation, solubility tests, UV-vis spectroscopy, differential
scanning calorimeter (DSC), thermogravimetric analysis (TGA), and derivative of thermaogravimetric (DTG). These macromolecules
exhibited maximum UV-vis absorption at around 370 and 265 nm in a DMF solution. 相似文献
9.
A series of highly branched poly(urethane–imide) (HBPUI) were synthesized via A2 + B3 approach using isophorone diisocyante (IPDI), polycarbonatediol (PCDL), 3,3′,4,4′-Benzophen-onetetracarboxylic dianhydride
(BTDA), and poly(oxyalkylene) triamine (ATA) as materials. The structure of the products was characterized by FT-IR and 13C-NMR. The molecular weights were characterized by gel permeation chromatograph (GPC). The solution viscosity, thermal, and
mechanical properties were measured by rotational rheometer, differential scanning calorimetry (DSC), thermal gravimetric
analysis (TGA), tensile tests, and dynamic mechanical analysis (DMA), respectively. The HBPUI showed lower viscosity than
that of linear poly(urethane–imide) (LPUI), nevertheless T
g of HBPUI was higher than that of LPUI. TGA indicated that the thermal degradation of poly(urethane–imide) occurred above
300 °C, which was higher than conventional polyurethane. The tensile strength of HBPUI was obviously improved by increasing
the content of BTDA and the molar ratio of [A2]/[B3]. The effects of the content of BTDA and the molar ratio of [A2]/[B3] on the storage modulus of the polymers were also studied. 相似文献
10.
Binary blends of the sulfonated poly(ether ether ketone) (SPEEK)–poly(ether imide) (PEI) and SPEEK–polycarbonate (PC), and ternary blends of the SPEEK–PEI–PC, were investigated by differential scanning calorimetry. SPEEK was obtained by sulfonation of poly(ether ether ketone) using 95% sulfuric acid. From the thermal analysis of the SPEEK–PEI blends, single glass transition temperature (Tg) was observed at all the blend composition. For the SPEEK–PC blends, double Tgs were observed. From the results of thermal analysis, it is suggested that the SPEEK–PEI blends are miscible and the SPEEK–PC blends are immiscible. Polymer–polymer interaction parameter (χ12) of the SPEEK–PEI blends was calculated from the modified Lu and Weiss equation, and found to range from −0.011 to −0.825 with the blend composition. For the SPEEK–PC blends, the χ12 values were calculated from the modified Flory–Huggins equation, and found to range from 0.191 to 0.272 with the blend composition. For the SPEEK–PEI–PC ternary blends, phase separation regions that showed two Tgs were found to be consistent with the spinodal curves calculated from the χ12 values of the three binary blends. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 78: 2488–2494, 2000 相似文献
11.
In this research a diamine monomer containing two phenoxy phenylene lateral groups, 2,2′-bis[(p-phenoxy phenyl)]-4,4′-diaminodiphenyl ether (PPAPE) was used to prepare novel wholly aromatic polyimides by thermal or chemical two-step polycondensation reactions. Comonomers
including pyromellitic dianhydride (PMDA), 4,4′-oxydiphthalic anhydride (ODPA), and 3,3′,4,4′-benzophenonetetracarboxylic dianhydride (BTDA) were used for the polyimidization reactions. A reference polyimide was also prepared by the reaction of 4,4′-diaminodiphenyl
ether (DADPE) with pyromellitic dianhydride (PMDA). The limited viscosity numbers as well as [`(M)]n \overline{M}_n and [`(M)]w \overline{M}_w values of the resulting polymers were determined. All PPAPE-resulted polyimides had excellent organosolubility in common polar solvents. A low crystallinity extent was only observed
using their wide-angle X-ray diffractograms (WAXD). The prepared hinged polyimides could also be cast into transparent and
flexible films. The glass transition temperatures of the resulting polyimides were determined by differential scanning calorimetry
(DSC) analyses. The thermograms obtained from thermogravimetric analyses (TGA) showed that the phenoxy phenylene lateral groups
attached to the macromolecular backbones had no substantial diminishing effect on the thermal stability of these structurally-modified
polyimides. 相似文献
12.
Summary Various approaches have been carried out in the synthesis of poly(amide-imide)s. A well-developed solution polycondensation
method has been used to prepare such copolymers either from a dianhydride containing a preformed amide group with a diamine
or from a dicarboxylic acid containing a preformed imide ring with a diamine. Direct polycondensations of carboxylic acids
and aromatic diamines can be a more useful technique for synthesis of poly(amide-imide)s PAIs. In this work, direct polymerization reaction of N,N’-(4,4’-hexafluoroisopropylidendiphthaloyl)-bis-L-isoleucine with several aromatic diamines such as 4,4’-diaminodiphenylsulphone
(4a), 4,4’-diaminodiphenylmethane (4b), 4,4’-diaminodiphenylether (4c), 1,4-phenylenediamine (4d), 4,4’-diaminobiphenyl (4e), 1,3-phenylenediamine (4f), 2,4-diaminotoluene (4g), was performed in the presence of tosyl chloride (TsCl)/dimethylformamide (DMF)/pyridine (Py) as a condensing agent. The
resulting PAIs were obtained in high yield and inherent viscosity. Some structural characterization and physical properties of these polymers
have been studied and will be reported. 相似文献
13.
Ming Zhu Xiao Liu Baijun Liu Zhenhuan Jiang Toshihiko Matsumoto 《Polymer Bulletin》2011,67(9):1761-1771
A new diamine monomer, 1,5-bis[4-(4-aminophenoxy)]benzoyl-2,6-dimethoxynaphthalene, was synthesized via a Friedel–Crafts acylation
reaction followed by an aromatic nucleophilic substitution reaction. Six ether–ketone linked polymers, named as poly(ether
ketone azomethane)s and poly(ether ketone imide)s, were successfully prepared through the polycondensations of the diamine
monomer with dialdehydes and dianhydrides, respectively. These naphthylated polymers exhibited high T
g values (142–288 °C), due to their bulky and rigid chemical structure. Meanwhile, they showed good thermal stability and improved
solubility. Typically, some of them were casted into thin flexible film and showed high moduli. 相似文献
14.
Leila Ben Maktouf Ines Ghorbel Aljia Afli Souhir Abid Alessandro Gandini 《Polymer Bulletin》2011,67(7):1111-1122
Novel polyimides containing furan moieties were prepared from the resulting furanic diamine monomers with various aromatic
dianhydrides including 1,2,4,5-benzene-tetracarboxylic dianhydride, 3,3′,4,4′-biphenyltetracarboxylic dianhydride, 4,4′-oxydiphthalic
anhydride, and hexafluoroisopropylidene 2,2-bis(phthalic anhydride), via a two-step process. The resulting polyimides were
characterized by solubility tests, viscosity measurements, FTIR, 1H NMR spectroscopy, differential scanning calorimetric (DSC), and thermogravimetric analysis (TGA) analysis. The polyimides
with inherent viscosities in the range of 0.048–0.095 L/g showed excellent solubility in aprotic amide and organic solvents,
such as N,N-dimethylacetamide, N-methyl-2-pyrrolidinone, dimethylformamide and acetone, chloroform, etc. DSC showed glass transition temperatures (T
g) in the range of 116–143 °C. These polymers showed excellent thermal stability up to 390 °C. 相似文献
15.
Four novel wholly para-oriented aromatic poly(ether-amide-hydrazide)s containing various pendant groups on their aromatic
rings were synthesized from p-aminosalicylic acid hydrazide (PASH) with an equimolar amount of either 4,4′-(1,4-phenylenedioxy)dibenzoyl
chloride (1a), 4,4′-(2,5-tolylenedioxy)dibenzoyl chloride (1b), 4,4′-(2-tert-butyl-1,4-phenylenedioxy)dibenzoyl chloride (1c),
or 4,4′-(2,5-biphenylenedioxy)dibenzoyl chloride (1d) via a low temperature solution polycondensation reaction. A polyamide-hydrazide
without the ether and pendant groups, poly[4-(terephthaloylamino)salicylic acid hydrazide, PTASH, is also investigated for
comparison. It was synthesized from PASH and terephthaloyl chloride by the same synthetic route. The polymer intrinsic viscosities
ranged from 4.5 to 2.47 dlg−1 in N,N-dimethyl acetamide (DMAc) at 30 °C and decreased with the introduction of the ether and pendant groups into the polymer.
All the polymers were soluble in DMAc, N,N-dimethyl formamide (DMF), and N-methyl-2-pyrrolidone (NMP) and their solutions
could be cast into flexible films with good mechanical strengths. Further, they exhibited a great affinity to water sorption.
Their solubility and hydrophilicity increased with introduction of the ether and pendant groups into the polymer. The prepared
polymers could be thermally cyclodehydrated under nitrogen atmosphere into the corresponding poly(ether-amide-1,3,4-oxadiazole)s
approximately in the region of 300–450 °C. The introduction of the flexibilizing ether linkages and the pendant groups into
the polymer improves the solubility of the resulting poly(ether-amide-1,3,4-oxadiazole)s compared to poly(amide-1,3,4-oxadiazole)
free from these groups. 相似文献
16.
Takeshi Nakato Masayuki Tomida Atsushi Kusuno Minako Shibata Toyoji Kakuchi 《Polymer Bulletin》1998,40(6):647-650
Summary
The polycondensations of L-aspartic acid (1) with aromatic aminocarboxylic acid, 4-aminobenzoic acid (2a), 4-aminophenylacetic acid (2b), 4-aminomethylbenzoic acid (2c), 4-(4-aminophenyl)butyric acid (2d), and 4-aminocinnamic acid (2e) were carried out using phosphoric acid as a catalyst. The obtained copolymers consiting of the succinimide and amide units,
poly(succinimide-co-amide) (3), were soluble in DMF and DMSO except for that with 2e. The thermal properties differed with varying the 2 unit in 3, i.e., the Tgs of 3a–c (99 ∼ 138°C) were higher than those of 3d (81 ∼ 1 01°C), the apparent difference in the Tm between 3a–d did not observed, and the Td decreased in the order of 3a, 3c > 3d > 3b.
Received: 24 February 1998/Revised version: 3 April 1998/Accepted: 13 April 1998 相似文献
17.
In order to develop a novel process for poly(arylene ether ketone)s with high thermal and chemical stability, a series of
poly(aylene ether ketone)s containing triazloe moieties were synthesized via the click chemistry of 4,4′-bis(azidomethyl)
diphenyl ketone (BADPK) and bisethynyl compounds (BEAE1-5). The resulting polymers were characterized by using IR and 1H NMR techniques. The solubility data showed that samples possessed good solubility in highly polar solvents. Molecular mass
of these samples was determined by GPC which indicated they exhibited reasonable molecules weights and relatively small polydispersity.
Furthermore, thermal stability of the samples was evaluated using thermogravimetric analysis (TGA) and differential scanning
calorimetry (DSC), which indicated that they possessed good thermal stability and high T
g (100–140 °C). All the polymers were amorphous confirmed by DSC and X-ray diffraction (WAXD). 相似文献
18.
Ching Hsuan Lin Jui Chun Chen Chu Ming Huang Jih Mirn Jehng Hou Chien Chang Tzong Yuan Juang Wen Chiung Su 《Polymer》2013
We prepared a side-chain phenol-functionalized poly(ether sulfone) (P1) from a one-pot reaction of a 4,4′-dihydroxybenzophenone (DHBP)-based poly(ether sulfone), poly(oxy-1,4-phenylenecarbonyl-1,4-phenyleneoxy-1,4-phenylene-sulfonyl-1,4-phenylene (DHBP-PES)), with 9,10-dihydro-oxa-10-phosphaphenanthrene-10-oxide (DOPO) and phenol in the presence of sulphuric acid. The phenol linkages of P1 act as reacting sites for epoxy resins. Subsequently, flexible and light-yellow transparent films of epoxy thermosets can be achieved from the curing of P1 with cresol novolac epoxy (CNE) and diglycidyl ether of bisphenol A (DGEBA). The thermoset based on P1 and CNE (P1/CNE) shows a high Tg value (241 °C), a low coefficient of thermal expansion (44 ppm/°C), and flame retardancy (VTM-0). The moderate-to-high molecular weight of P1 is responsible for the characteristics high Tg and flexibility, which are rarely seen in epoxy thermosets based on a low-molecular weight curing agent. 相似文献
19.
Zheng Chen Robert J. Ono Honglei Cui Christopher W. Bielawski Zhenhua Jiang 《Polymer》2011,52(8):1731-1737
Condensation of 9-(4-aminobenzene)-carbazole with 4,4′-difluorobenzophenone afforded a carbazole-functionalized poly(aryl amino ketone) (PAK-Cz). Similarly, a series of poly(ether ether ketone)s (PEEK-Cz) and poly(arylene ether ketone)s (PAEK-Cz) containing pendant carbazoles were synthesized from the copolymerization of 9-(4-aminobenzene)-carbazole, 4,4′-difluorobenzophenone and 4,4′-biphenol or 4,4′-isopropylidenebiphenol, respectively. The aforementioned polymers exhibited polystyrene equivalent number average molecular weights of up to 36 kDa, and were found to be thermally stable with high decomposition (Td) (469-569 °C) and glass transition temperatures (Tg) (155-256 °C). UV-vis absorption and fluorescence spectra revealed that these materials exhibited highly efficient (Φf = 0.41-0.66) yellow-green emission (λem = 500-514 nm) in solution. 相似文献
20.
Bhausaheb V Tawade Sayali V Shaligram Nitin G Valsange Ulhas K Kharul Prakash P Wadgaonkar 《Polymer International》2016,65(5):567-576
A new biphenol, 3‐pentadecyl 4,4′‐biphenol, was synthesized starting from 3‐pentadecylphenol and was polycondensed with 4,4′‐difluorobenzophenone, 1,3‐bis(4‐fluorobenzoyl)benzene and bis(4‐fluorophenyl)sulfone to obtain poly(arylene ether)s with biphenylene linkages in the backbone and pendent pentadecyl chains. Inherent viscosities and number‐average molecular weights (Mn) of the poly(arylene ether)s were in the range 0.50 ? 0.81 dL g?1 and 2.2 × 104 ? 8.3 × 104, respectively. Detailed NMR spectroscopic studies of the poly(arylene ether)s indicated the presence of constitutional isomerism which existed because of the non‐symmetrical structure of 3‐pentadecyl 4,4′‐biphenol. The poly(arylene ether)s readily dissolved in common organic solvents such as dichloromethane, chloroform and tetrahydrofuran and could be cast into tough, transparent and flexible films from their chloroform solutions. The poly(arylene ether)s exhibited Tg values in the range 35–60 °C which are lower than that of reference poly(arylene ether)s without pentadecyl chains. The 10% decomposition temperatures (T10) of the poly(arylene ether)s were in the range 410–455 °C indicating their good thermal stability. A gas permeation study of poly(ether sulfone) containing pendent pentadecyl chains revealed a moderate increase in permeability for helium, hydrogen and oxygen. However, there was a large increase in permeability for carbon dioxide which could be attributed to the internal plasticization effect of pendent pentadecyl chains. © 2016 Society of Chemical Industry 相似文献