Paper Title
Synthesis Of Sulfonated Poly (Arylene Ether)S Membranesimported Trifluorinemethylgroup For Proton Exchange Membrane Of Fuel Cell

A series of sterically-encumbered, sulfonated, fluorine-containing poly(arylene ether) were synthesized so as to compare the effects of incorporating trifluoromethyl groups on the proton conductivity and performance of fuel cells of membranes prepared. The polymers were prepared by polymerization of 4,4-dihydroxybiphenyl or 4,4'-(9-fluorenylidene) diphenol with two novel monomers. The weight-average molecular weight of polymers ranging from 1.21×105 g/mol to 2.17×105g/mol. Subsequent sulfonation and solution casting provided membranes possessing ion exchange capacities ranging from 2.67 to 2.69mmol g-1. Good thermal properties of polymers were indicated by observing decomposition temperatures (Td5%) over 250oC in acid-form in nitrogen atmospheres. Water uptake ranged from 70 to 96 %, and dimensional stability (in-plane) ranged from 25 to 28% at 80 oC. All the sulfonated polymers exhibited highly chemical stability, mechanical properties and high hydrolytic stability. Especially the S12FP4-10 membrane exhibited only 35% in-plane dimensional changing at 80oC in the water and the proton conductivity up to 191mS/cm at 80 oC/95%RH. We infer that introducing the trifluoromethyl into the polymer by way of incorporating highly sulfonated, multi-phenylated moieties provides mechanically-robust and dimensionally-stable proton exchange membranes. Keyword- Fuel Cells, Proton Exchange Membrane, Poly(Arylene Ether)S, Trifluoromethyl