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1.
A series of sulfonated poly(aryl ether sulfone) copolymers containing phenyl pendant groups with sulfonic acid groups on the backbone were synthesized through condensation polymerization. The degree of sulfonation (DS) of the copolymers was controlled by changing the feed ratios of sulfonated to unsulfonated monomers. Post‐crosslink reactions are carried out with 4,4′‐thiodibenzoic acid (TDA) as a crosslinker and the carboxylic acid groups in TDA can undergo Friedel–Craft acylation with the phenyls pendent rings in sulfonated poly(arylene ether sulfone)s copolymers to prepare polymer electrolyte membranes for fuel cell applications. The chemical structures of crosslinked and uncrosslinked sulfonated poly(arylene ether sulfone)s copolymers (SPSFs and CSPSFs) were characterized by FTIR, 1H NMR spectra. The thermal and mechanical properties of the membranes were characterized by thermogravimetric analysis and stress–strain test. The dependence of water uptake, methanol permeability, proton conductivity, and selectivity on DS was studied. Transmission electron microscopic observations revealed that SPSFs and CSPSFs membranes form well‐defined microphase separated structures. POLYM. ENG. SCI., 54:2013–2022, 2014. © 2013 Society of Plastics Engineers  相似文献   

2.
The purity of the disulfonated monomer, 3,3′-disulfonated-4,4′-dichlorodiphenyl sulfone (SDCDPS), is very important for obtaining high molecular weight disulfonated poly(arylene ether sulfone) random or block copolymers, which are promising candidates for proton exchange membrane (PEM) fuel cells. For commercialization purposes, direct use of unrecrystallized SDCDPS monomer with known purity in the copolymerization favorably influences its economics relative to the traditional recrystallization purification process. In this paper, a novel method to characterize the purity of the prepared unrecrystallized SDCDPS has been developed using UV–vis spectroscopy. The purity of the comonomer was determined from a Beers Law calibration curve developed using a highly purified SDCDPS sample. High molecular weight poly(arylene ether sulfone) random copolymers, based on this unrecrystallized SDCDPS monomer, 4,4′-dichlorodiphenyl sulfone (DCDPS), and 4,4′-biphenol monomers, were successfully synthesized. The molecular weight obtained from gel permeation chromatography (GPC) (Mn > 45 kg mol?1) was high enough to allow tough films for PEMs to be solvent cast. This confirmed that the purity characterization method was relatively accurate and applicable. The effect of storage and drying time of SDCDPS were also studied using Beer's Law plots.  相似文献   

3.
Novel aromatic sulfonated poly(ether ether sulfone)s (SPEESs) with tert‐butyl groups were synthesized by aromatic nucleophilic polycondensation of disodium 3,3′‐disulfonate‐4,4′‐dichlorodiphenylsulfone (SDCDPS), 4,4′‐dichlorodiphenylsulfone (DCDPS), and tert‐butylhydroquinone (TBHQ). The resulting copolymers showed very good thermal stability and could be cast into tough membranes. The morphology of the membranes was investigated with atomic force microscopy. The proton conductivity of SPEES‐40 membranes increased from 0.062 S/cm at 25°C to 0.083 S/cm at 80°C, which was higher than the 0.077 S/cm of Nafion 117 under the same testing conditions. These copolymers are good candidates to be new polymeric electrolyte materials for proton exchange membrane fuel cells. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 1443–1450, 2007  相似文献   

4.
Sulfonated poly(ether ether ketone sulfone) (SPEEKS) and sulfonated poly(ether ether ketone ketone sulfone) (SPEEKKS) copolymers with different degree of sulfonation (DS) were synthesized by aromatic nucleophilic polycondensation of disodium 3,3′‐disulfonate‐4,4′‐dichloro‐diphenylsulfone (SDCDPS), tertbutylhydroquione, and 4,4′‐difluorobenzophenone or 1,4′‐bi(4‐fluorobenzoyl) benzene. Prepared sulfonated copolymers were characterized by Fourier transform infrared spectra, thermogravimetric analysis, and differential scanning calorimetry. The transmission electron microscope was used to investigate the microstructure of membranes. The different distance between two adjacent sulfonic groups in two series of membranes resulted in different physical and electrochemical properties between two kinds of membranes with the same DS. The proton conductivity, ionic exchange capacity and water uptake of SPEEKS membranes were higher than those of SPEEKKS membranes while the mechanical strength of SPEEKS membranes was lower than that of SPEEKKS membranes at the same DS. Moreover, the SPEEKKS membranes with DS equals to 0.8 showed a good combination of a high proton conductivity (0.046 S/cm at 25°C, 0.061 S/cm at 80°C), acceptable water uptake (33–65 wt %), excellent mechanical strength (tensile strength reached 49.7 MPa), and good thermal properties (Tg above 250°C, Td5% above 300°C). It suggested that this could be a promising membrane for proton exchange membrane fuel cell application. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009  相似文献   

5.
Novel bisphenol A‐based sulfonated poly(arylene ether sulfone) (bi A‐SPAES) copolymers were successfully synthesized via direct copolymerization of disodium 3,3′‐disulfonate‐4,4′‐dichlorodiphenylsulfone, 4,4′‐dichlorodiphenylsulfone, and bisphenol A. The copolymer structure was confirmed by Fourier transform infrared spectra and 1H NMR analysis. The series of sulfonated copolymers based membranes were prepared and evaluated for proton exchange membranes (PEM). The membranes showed good thermal stability and mechanical property. Transmission electron microscopy was used to obtain the microstructures of the synthesized polymers. The membranes exhibit increased water uptake from 8% to 66%, ion exchange capacities from 0.41 to 2.18 meq/g and proton conductivities (25°C) from 0.012 to 0.102 S/cm with the degree of sulfonation increasing. The proton conductivities of bi A‐SPAES‐6 membrane (0.10–0.15 S/cm) with high‐sulfonated degree are higher than that of Nafion 117 membrane (0.095–0.117 S/cm) at all temperatures (20–100°C). Especially, the methanol diffusion coefficients of membranes (1.7 × 10?8 cm2/s–8.5 × 10?7 cm2/s) are much lower than that of Nafion 117 membrane (2.1 × 10?6 cm2/s). The new synthesized copolymer was therefore proposed as a candidate of material for PEM in direct methanol fuel cell. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009  相似文献   

6.
A series of novel poly(aryl ether sulfone) copolymers containing dicyanophenyl group were prepared by the reaction of bis(4‐chlorophenyl)sulfone with (3,4‐dicyano) phenylhydroquinone and 4,4′‐isopropylidenediphenol. On this basis, a series of poly(aryl ether sulfone)s containing metallophthalocyanine units were synthesized by the reaction of poly(aryl ether sulfone)s containing dicyanophenyl group with excessive amounts of 1,2‐dicyanobenzene and the corresponding metal salt in quinoline. All these copolymers were found to have high glass transition temperature and thermal stability. These copolymers were found to be soluble in common solvents, and capable of forming transparent films by solution casting. The copolymers containing metallophthalocyanine units showed strong optical absorption in the visible region, and exhibited blue photoluminescence in solution. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 3457–3461, 2006  相似文献   

7.
Two monomers, 4,4′‐bis(4‐phenoxybenzoyl)biphenyl (BPOBBP) and 4,4′‐diphenoxydiphenyl sulfone (DPODPS), were conveniently synthesized via simple synthetic procedures from readily available materials. A series of novel poly(aryl ether ketone)s containing both biphenylene moieties and sulfone linkages in the main chain were synthesized by the modified electrophilic Friedel‐Crafts acylation copolycondensation of isophthaloyl chloride (IPC) with a mixture of BPOBBP and DPODPS, over a wide range of BPOBBP/DPODPS molar ratios. The resulting polymers were characterized by Fourier transform infrared spectroscopy (FT‐IR), wide‐angle X‐ray diffraction (WAXD), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA), etc. The results indicated that the copolymers with 30 to 35 mol% DPODPS were semicrystalline and had remarkably increased glass transition temperatures (Tgs) over the conventional poly(ether ether ketone) (PEEK) and poly(ether ketone ketone) (PEKK) due to the incorporation of biphenylene units and sulfone linkages in the main chain. The copolymers with 30 to 35 mol% DPODPS had not only high Tgs of 176 to 177°C, but also moderate melting temperatures (Tms) of 334 to 337°C, having good potential for the melt processing. The semicrystalline copolymers II to V had tensile strengths of 99.8 to 103.1 MPa, Young's moduli of 2.26 to 2.79 GPa, and elongations at break of 16.8 to 26.5% and exhibited outstanding thermal stability and good resistance to organic solvents. POLYM. ENG. SCI., 55:2140–2147, 2015. © 2015 Society of Plastics Engineers  相似文献   

8.
In order to overcome the poor flowability of poly(arylene sulfide sulfone) (PASS), we introduced ether bonds into the polymer main chain. A series poly(arylene ether sulfide sulfone) copolymers (PAESS) containing different proportion of ether bonds were synthesized with 4,4′‐dichlorodiphenyl sulfone (DCDPS), sodium sulfide (Na2xH2O), and 4,4′‐dihydroxydiphenyl ether (DHDPE). The copolymers were characterized by Fourier transform infrared (FTIR), 1H‐nuclear magnetic resonance (NMR), differential scanning calorimetry, dynamic mechanical analysis (DMA), and rheometer. The results of FTIR and 1H‐NMR indicate the copolymers are synthesized successfully. PAESS were found to have excellent thermal properties with glass transition temperature (Tg) of 175.7–219.1 °C and 5% weight lost temperature were all above 420 °C. The tensile and DMA test indicates that these resultant copolymers have good mechanical properties with tensile strength of 60 MPa and storage modulus of 1.5 GPa. From the results of rheology properties testing, we found that the melt stability and melt flowability of PASS were improved distinctly from 25,470 Pa s down to 355 Pa s with the incorporation of ether bonds. That will be quite beneficial to the processing of PASS, especially for the thermoforming of precision products. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46534.  相似文献   

9.
以4,4’-二氯二苯砜、4,4’-二羟基二苯砜和2,4-二羟基二苯砜为单体,通过缩聚合成一系列主链含异构体醚键单元的聚芳醚砜共聚物,利用核磁共振碳谱(13C NMR)、差示扫描量热分析(DSC)和高压毛细管流变仪对产物进行了测试和分析。对比不同产物的熔体黏度、玻璃化转变温度和力学性能,发现随着共聚单元含量的增加,聚芳醚砜共聚物的流动性逐渐提高,玻璃化转变温度逐渐降低,并且屈服点伸长率和缺口冲击强度均逐渐提高。这一结果对实际应用中提高聚芳醚砜树脂流动性和韧性、降低热加工温度等具有重要的指导意义。  相似文献   

10.
The influence of chemical compositions on the properties of sulfonated poly(arylene ether sulfone)‐based proton‐exchange membranes was studied. First, we synthesized three different series of random SPAES copolymers using three kinds of hydrophobic monomers, including 4,4′‐dihydroxyldiphenylether, 2,6‐dihydroxynaphthalene (DHN), and 4,4′‐hexafluoroisopropylidenediphenol (6F‐BPA) to investigate effects of hydrophobic components on the properties of SPAES membranes as proton‐exchange membranes. Random SPAES copolymers with 6F‐BPA showed the highest proton conductivity while random SPAES copolymers with DHN displayed the lowest methanol permeability among the three random copolymers. Subsequently, we synthesized multiblock SPAES using the DHN as a hydrophobic monomer and studied the effect of the length of hydrophilic segments in the multiblock SPAES copolymers on membrane performance. The results indicated that longer hydrophilic segments in the copolymers led to higher water uptake, proton conductivity, and proton/methanol selectivity of membranes even at low humidity. In addition, the morphology studies (AFM and SAXS measurements) of membranes suggested that multiblock copolymers with long hydrophilic segments resulted in developed phase separation in membranes, and ionic clusters formed more easily, thus improving the membrane performance. Therefore, both the kinds of hydrophobic monomers and the length of hydrophilic segments in SPAES copolymers would influence the membranes performance as proton‐exchange membranes. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010  相似文献   

11.
A series of sulfonated poly(arylene ether sulfone) (PAES) were synthesized through direct aromatic nucleophilic substitution polycondensation of 3,3′-disulfonate-4,4′-dichlorodiphenylsulfone (SDCDPS), 4,4-dichlorodiphenylsulfone (DCDPS) and 4,4-biphenol (BP). With increasing sulfonate groups in the polymer, water uptake, ion exchange capacity (IEC) and proton conductivities increased, resulting from enhanced membrane hydrophilicity. The membranes exhibited higher thermal stability up to 300 °C, verified by thermogravimetric analysis (TGA). A maximum proton conductivity of 0.11 S/cm at 50 mol% of sulfonation degree was measured at 30 °C, which is slightly higher than Nafion®117 membrane (0.0908 S/cm). However, the methanol permeability of the PAES membrane was much lower than that of Nafion®117 membrane. As a result, a single cell performance test demonstrated that PAES-BP with 50 mol% sulfonation degree exhibited higher power density than Nafion®117.  相似文献   

12.
Summary The new sulfone-activated difluoro monomers with benzoyl substituents, bis(2-benzoyl-4-fluorophenyl) sulfone and 2-benzoyl-4,4'-difluorophenyl sulfone, were synthesized and converted to the corresponding poly(aryl ether sulfone)s with bisphenol A. While homopolymerization of the two monomers gave low molecular weight polymers because of cleavage of sulfone induced by the pendent benzoyl group at ortho position, copolymerization with his(4-fluorophenyl) sulfone comonomer produced moderately high molecular weight polymers. The inherent viscosities of the synthesized polymers were 0.20–0.38 dL/g and the glass transition temperatures of the polymers were 173–195°C. Thermogravimetric analysis showed that thermal stability of the polymers decreased as the polymers contain more benzoyl substituents. Received: 15 May 1998/Revised version: 13 October 1998/Accepted: 4 November 1998  相似文献   

13.
Hossein Ghassemi 《Polymer》2006,47(11):4132-4139
New proton exchange membranes were prepared and evaluated as polymer electrolytes for a proton exchange membrane fuel cell (PEMFC). Sulfonated-fluorinated poly(arylene ether) multiblocks (MBs) were synthesized by nucleophilic aromatic substitution of highly activated fluorine terminated telechelics made from decafluorobiphenyl with 4,4′-(hexafluoroisopropylidene)diphenol and hydroxyl-terminated telechelics made from 4,4′-biphenol and 3,3′-disulfonated-4,4′-dichlorodiphenylsulfone. Membranes with various sulfonation levels were successfully cast from N-methyl-2-pyrrolidinone. An increase sulfonated block size in the copolymer resulted in enhanced membrane ion exchange capacity and proton conductivity. The morphological structure of MB copolymers was investigated by tapping mode atomic force microscopy (TM-AFM) and compared with those of Nafion® and sulfonated poly(arylene ether) random copolymers. AFM images of MBs revealed a very well defined phase separation, which may explain their higher proton conductivities compared to the random copolymers. The results are of particular interest for hydrogen/air fuel cells where conductivity at high temperature and low relative humidity is a critical issue.  相似文献   

14.
Disulfonated poly(arylene ether sulfone) (BPS) random copolymers, prepared from a sulfonated monomer, have been considered for use as membrane materials for various applications in water purification and power generation. These membranes can be melt-processed to avoid the use of hazardous solvent-based processes with the aid of a plasticizer, a low molecular weight poly(ethylene glycol) (PEG). PEG was used to modify the glass transition temperature and melt rheology of BPS to enable coextrusion with polypropylene (PP). Our previous paper discussed the miscibility of BPS with PEG and the influence of PEG on the glass transition of BPS. In this study, the rheological properties of disulfonated poly(arylene ether sulfone)s plasticized with poly(ethylene glycol) (PEG) are investigated to identify coextrusion processing conditions with candidate PPs. The effects of various factors including PEG molecular weight, PEG concentration, temperature and BPS molecular weight on blend viscosity were studied. The rheological data effectively lie on the same master curve developed by Bueche and Harding for non-associating polymers such as poly(methyl methacrylate) (PMMA) and polystyrene (PS). Although sulfonated polysulfone contains ionic groups, the form of its viscosity versus shear rate (or frequency) behavior appears to be dominated by the relaxation of polymer entanglements.  相似文献   

15.
The main drawback of direct methanol fuel cells is methanol crossover. One strategy to overcome this problem is design of new polymeric membranes. Two structurally different diols named as 4,4′-(1,4-phenylene diisopropylidene) bisphenol and 4,4′-(1,3-phenylene diisopropylidene) bisphenol (para- and meta-substituted monomers) were used to prepare two groups of poly(arylene ether sulfone)s with different structures and related membranes therefrom by solution casting. It was found that para- or meta-substitution positions in monomers affected the methanol permeability of membranes. Other influenced properties of resulted membranes such as ion exchange capacity, water uptake, proton conductivity, glass transition temperature, and mechanical strength were studied and compared.  相似文献   

16.
Sulfonated cardo poly(arylene ether sulfone)s ( SPPA ‐ PES ) with various degrees of sulfonation (DS) were prepared by post‐sulfonation of synthesized phenolphthalein anilide ( PPA ; N‐phenyl‐3,3′‐bis(4‐hydroxyphenyl)‐1‐isobenzopyrolidone) poly(arylene ether sulfone)s ( PPA ‐ PES ) by using concentrated sulfuric acid. PPA ‐ PES copolymers were synthesized by direct polycondensation of PPA with bis‐(4‐fluorophenyl)‐sulfone and 4,4′‐sulfonyldiphenol. The DS was varied with different mole ratios of PPA (24, 30, 40, 50 mol.%) in the polymer. The structure of the resulting SPPA ‐ PES copolymers and the different contents of the sulfonated unit were studied by Fourier transform infrared (FT‐IR) spectroscopy, 1H NMR spectroscopy, and thermogravimetric analysis (TGA). Sorption experiments were conducted to observe the interaction of sulfonated polymer with water. The ion exchange capacity (IEC) and proton conductivity of SPPA ‐ PES were evaluated according to the increase of DS. The water uptake (WU) of the resulting SPPA ‐ PES membranes was in the range of 20–72%, compared with 28% for Nafion 211®. The SPPA ‐ PES membranes showed proton conductivities of 23–82 mS cm–1, compared with 194 mS cm–1 for Nafion 211®, under 100% relative humidity (RH) at 80 °C.  相似文献   

17.
A composite membrane of sulfonated poly(ether sulfone) (SPES)/poly(ether sulfone) (PES) nanofiber (NF) mat impregnated with Nafion was prepared and evaluated for its potential use as a proton conductor for proton exchange membrane (PEM) fuel cells. The supporting composite nanofibrous mat was prepared by solution blowing of a mixture of SPES/PES solution. The characteristics of the SPES/PES NF and the composite membrane, such as morphology, thermal stability, and performance of membrane as PEMs, were investigated. The performance of composite membranes was compared with that of Nafion117. The introduction of solution blown NFs to composite membranes modestly improved proton conductivity, water swelling, and methanol permeability. Therefore, composite membrane containing SPES/PES NFs can be considered as a novel PEM for fuel cell applications. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42572.  相似文献   

18.
Frank Schönberger 《Polymer》2010,51(19):4299-4313
A series of partially fluorinated poly(arylene ether)s with systematical structure variations (variations in the (bi)phenylene, bisphenol moiety, and the fluorine content) was synthesized and characterized. Main objective of this contribution was the investigation of structure-property relationships of the different polymer structures, and how the chemical structure of the aromatic monomers influences (1) polymerisability of the monomers; (2) chemical and thermal stability of the poly(arylene ether)s, and (3) properties of the referring sulfonated polymers, particularly their chemical and mechanical stability. Polymers from this series comprising high molecular weight and excellent film-forming properties were targeted to various sulfonation routes, and their degradation behavior during sulfonation was investigated by gel permeation chromatography (GPC). Finally, (polybenzimidazole blend) membrane properties of the most promising candidates for potential application in polymer electrolyte membrane fuel cells were evaluated. The best of the investigated blend membranes was investigated in an air-breathing DMFC and yielded markedly improved performance, compared to Nafion®105. This study gives both insight into structure-property-relationships and directions for future polymer and membrane developments.  相似文献   

19.
Juan Yang  Abhishek Roy 《Polymer》2008,49(24):5300-5306
tert-Butylphenyl-terminated disulfonated poly(arylene ether sulfone) random copolymers with a sulfonation degree of 35 mol% (BPS35) and controlled molecular weights (Mn), 20-50 kg mol−1, were successfully prepared by direct copolymerization of the two activated halides, 4,4′-dichlorodiphenyl sulfone (DCDPS) and 3,3′-disulfonate-4,4′-dichlorodiphenyl sulfone (SDCDPS) with 4,4′-biphenol and the endcapper, 4-tert-butylphenol. Dilute viscosity measurements of the BPS35 random copolymers were successfully conducted in NMP containing various concentrations of LiBr from 0.01 to 0.2 M and mostly at 0.05 M according to the measured theory. The effects of salt concentration and molecular weights of the copolymers on the viscometric behavior were studied and compared with published data for sulfonated polystyrene. The charge density parameter (ξ) for the BPS35 copolymers was determined to be smaller than 1, suggesting that no counterion condensation occurs. Studies of the effect of ionic strength (I) on the intrinsic viscosities ([η]) under theta condition were obtained by plotting [η] vs. I−1/2 and extrapolating to infinite ionic strength. For salt-free BPS35 solutions, the viscometric behavior was shown to fit well with the Liberti-Stivala equation, providing a way to determining intrinsic viscosity when the copolymer charge is fully screened. Intrinsic viscosity and molecular weight characterization of BPS35 copolymers by SEC and static light scattering are also presented. The results are very useful for characterizing polymeric electrolyte membrane (PEM) for fuel cells, reverse osmosis and ionic transducer membranes.  相似文献   

20.
A new monomer containing sulfone and imide linkages, bis{4-[4-(p-phenoxyphenylsulfonylphenoxy)benzoyl]-1,2-benzenedioyl}-N,N,N′,N′-4,4′-diaminodiphenyl ether (BPSPBDADPE), was prepared by the Friedel–Crafts reaction of bis(4-chloroformyl-1,2-benzenedioyl)-N,N,N′,N′-4,4′-diaminodiphenyl ether with 4,4′-diphenoxydiphenyl sulfone. Novel copolymers of poly(ether ketone ketone) and poly(ether ketone sulfone imide) were synthesized by electrophilic Friedel–Crafts solution copolycondensation of terephthaloyl chloride with a mixture of DPE and BPSPBDADPE. The polymers were characterized by different physico-chemical techniques. The polymers with 10–25?mol% BPSPBDADPE are semicrystalline and had increased T gs over commercially available PEEK and PEKK (70/30) due to the incorporation of sulfone and imide linkages in the main chains. The polymer IV with 25?mol% BPSPBDADPE had not only high T g of 194?°C but also moderate T m of 338?°C, having good potential for melt processing and exhibited high thermal stability and good resistance to common organic solvents.  相似文献   

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