Pendant crosslinked poly(aryl ether sulfone) copolymers sulfonated on backbone for proton exchange membranes

Abstract

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

Crosslinked poly(ether ether ketone): cost-effective proton exchange membranes for fuel cell application

“…The pendant carboxylic or sulphonic acid groups present on the main backbone of the polymer chain enhance the proton conductivity of the membrane [12][13][14]. These pendant groups have also been utilized further for crosslinking to improve the dimensional stability and various fuel-cell-related properties of the pristine membrane [15,16]. Studies of poly(vinyl alcohol) [PVA]-based membranes have shown that they possess excellent film-forming properties, besides showing high chemical resistance and thermo-stability [17].…”

Sulfonated poly (arylene ether sulfone) proton exchange membranes for fuel cell applications

“…These include poly(arylene ether ketone)s, poly(arylene ether sulfone)s (PAESs) [6][7][8][9][10][11], poly(arylene ether nitrile)s [12,13], poly(phthalazinone arylene ether)s [14,15], polyimides [16][17][18]. Extensive work has also been carried out on polybenzimidazole based membranes which represents the class of PEMs having acid-base interactions and are suitable for high temperature operating fuel cell applications.…”

Synthesis and characterization of new proton exchange membrane deriving from sulfonated polyether sulfone using ionic crosslinking for electrodialysis applications

“…Until now, several different polymers have been used for membranes in ED applications, such as, polystyrene, [ 12,13 ] polyether imide, [ 14,15 ] polyether ether ketone, [ 16,17 ] polyether benzimidazole, [ 18,19 ] and polyarylene ether. [ 20‐22 ] The sulfonation of these polymers leads to improved membrane properties, that is, better wettability, better permselectivity, higher water flux, higher ionic conductivity, and better ionic exchange capacity. Those improved properties make these sulfonated polymers good candidates for IEM commercial materials.…”