New Composite Proton-Conducting Membranes Based on Nafion and Cross-Linked Sulfonated Polystyrene

New composite membranes based on commercial perfluorinated Nafion-115 membrane and cross-linked sulfonated polystyrene were synthesized and investigated. The membranes were prepared by radical polymerization of styrene in the presence of a cross-linking agent divinylbenzene in Nafion polymer matrix and subsequent sulfonation of formed polystyrene. The membranes containing approximately 5 and 10 wt % of cross-linked polystyrene with ion-exchange capacity of 1.1 to 1.3 mg-eq/g were obtained. Modification with sulfonated polystyrene leads to an increase in the moisture content and proton conductivity of membranes in the humidity range of 15 to 100 RH.