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51.
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
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Rui Lei Chuanqing Kang Yunjie Huang Yuhan Li Xi Wang Rizhe Jin Xuepeng Qiu Xiangling Ji Wei Xing Lianxun Gao 《应用聚合物科学杂志》2009,114(5):3190-3197
A series of sulfonated polyimides (SPIs) containing pyridine ring in the polymer backbone were synthesized by the polycondensation of 1,4,5,8‐naphthalene‐tetracarboxylic dianhydride (NTDA), 5‐(2,6‐bis(4‐aminophenyl)pyridin‐4‐yl)‐2‐methoxy benzene sulfonic acid (SDAM), and 4,4′‐diaminodiphenyl ether (ODA). Flexible, transparent, and tough membranes were obtained. Property study revealed that all the membranes displayed high thermal stability with the desulfonation and decomposition temperature higher than 290 and 540°C, respectively, as well as good mechanical property with Young's modulus larger than 1.0 GPa, maximum strength (MS) on a scale of 60–80 MPa, and elongation at break (EB) ranged from 41.79 to 75.17%. More importantly, the new materials exhibited small water uptake and excellent dimensional stability with the highest sulfonated SPI‐80 showing the maximum water uptake of 36.1%, and maximum swollen ratio of Δt = 0.038 and Δl = 0.026, respectively (Δt and Δl stands for the thickness and diameter change of the film, respectively). The high water stability exhibited by the SPI films is attributed to the formation of inner salts and/or ionic crosslinking between the sulfonic acid and pyridine functional groups, which suppresses the water uptake ability of sulfonic acid and strengthened the interpolymer chain interactions. Thus, the excellent water stability, good thermal and mechanical properties, and the technologically applicable conductivity of SPI‐80 render this material attractive for proton exchange membrane (PEM) application. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009 相似文献
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Polyethersulfone (PES) is widely used as biomaterials due to its thermal stability, mechanical strength, and chemical inertness. Nevertheless, their blood compatibility is still not adequate for hemodialysis and blood pu-rification. In this study, the sulfonated polyethersulfone (SPES) was synthesized through an electrophilic substitu-tion reaction, and PES/SPES blending membranes were prepared. The characterization of the SPES was studied by FTIR. The water adsorption and water contact angle experiments show that the hydrophilicity of PES/SPES blend membrane was improved as for the sulfonate group existing in the SPES. Moreover, PES/SPES blend membrane could effectively reduce bovine serum albumin adsorption and prolong the blood coagulation time compared with the PES membrane, thereby improving blood compatibility. 相似文献
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以甘草酸的单次萃取率及甘草酸与甘草苷的分离率为指标,以0.2 g/mL的甘草超滤液为研究对象,在单因素实验基础上,应用析因实验考察络合萃取剂组成变化对甘草超滤液中甘草酸萃取效果的影响,优选出适合甘草酸分离的络合萃取剂及方法。结果表明:15%三烷基氧磷(TRPO)+85%磺化煤油对甘草超滤液中甘草苷的单次萃取率为99.59%,甘草苷与甘草酸的分离率为91.31%;6% TRPO+50%磷酸三丁酯(TBP)+44%磺化煤油对甘草酸的单次萃取率为32.98%±0.04%。得到先用15% TRPO+85%磺化煤油络合萃取超滤液中的甘草苷,再以6% TRPO+50% TBP+44%磺化煤油为萃取剂,萃取萃余水相中甘草酸的两步络合萃取法。该两步络合萃取法既能得到甘草酸,同时还可收集到副产品甘草苷。 相似文献
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《International Journal of Hydrogen Energy》2022,47(14):8883-8891
A series of novel branched sulfonated polyimide (bSPI-x) membranes with 8% branched degree are developed for application in vanadium redox flow battery (VRFB). The sulfonation degrees of bSPI-x membranes are precisely regulated for obtaining excellent comprehensive performance. Among all bSPI-x membranes, the bSPI-50 membrane shows strong vanadium permeability resistance, which is as 8 times as that of commercial Nafion 212 membrane. At the same time, the bSPI-50 membrane has remarkable proton selectivity, which is four times as high as that of Nafion 212 membrane. The bSPI-50 membrane possesses slower self-discharge speed than Nafion 212 membrane. Furthermore, the bSPI-50 membrane achieves stable VRFB efficiencies during 200-time charge-discharge cycles at 120–180 mA cm?2. Simultaneously, the bSPI-50 membrane exhibits excellent capacity retention compared with Nafion 212 membrane. All results imply that the bSPI-50 membrane possesses good application prospect as a promising alternative separator of VRFB. 相似文献
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Jun Xiang Xinxin Hua Xingfeng Dong Penggao Cheng Lei Zhang Wei Du Na Tang 《应用聚合物科学杂志》2019,136(15):47525
Different nonsolvent additives, namely, diethylene glycol, n-butyl alcohol (NBA), and ethylene glycol monomethyl ether, were added into the casting solution (polyethersulfone/dimethylformamide/lithium chloride) to prepare ultrafiltration (UF) membrane via phase inversion. The effects of different additives and their concentration on the pore structure of the prepared UF membrane were studied. The cross-sectional morphology of the membrane was observed via scanning electron microscopy. The addition of nonsolvent additives improved the large-cavity structure of the membrane. When the additive was low-content NBA (1–3 wt %), the membrane pore structure transformed from large-cavity structure to fully sponge-like structure. When the content of additive NBA was 3 wt %, the flux of the prepared UF membrane was 130.45 L (m−2 h−1), the rejection of PEG20000 was 95.54% and the flux remained high at 4 bar in long-term stability test. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47525. 相似文献
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