Covalently cross-linked ionomer (blend) membranes for fuel cells

摘要

In this contribution the synthesis and characterisation of novel types of covalently cross-linked blend membranes is reported. The membranes are composed of different types of sulfochlorinated poly(etherketones) and sulfinated polyethersulfone or polyetherketone arylpolymers, where the sulfinate groups were cross-linked by S-alkylation reactions with bifunctional halogeno-compounds, among them alpha,omega-diiodoalkanes or aromatic difluoro-compounds like bis(4-fluorophenyl)sulfone, bis(3-nitro-4-fluorophenyl)sulfone or bis(4-fluorophenyl)phenylphosphinoxide. After membrane formation the sulfochloride groups of the membranes were hydrolyzed by aqueous posttreatment. Transparent, morphologically homogeneous, mechanically stable and highly H+-conductive ionomer membranes were obtained. To investigate the influence of different parameters onto the membrane properties, the type and the ion-exchange capacity (IEC) of sulfonated polyetherketone, the type of sulfinated polymer the mass relation between the sulfonated polyetherketone and the sulfinated polymer the type of cross-linker and the cross-linking density, of the membranes has been varied systematically. The results of this work are presented in this contribution.