Highly stable polyphenylene ionomer membranes from dichlorobiphenyls

A simple, cost-effective synthetic strategy for highly stable, proton conductive polyphenylene membranes is reported. The title polyphenylene ionomer (SPP-BP) is easily prepared from dichlorobenzenesulfonic acid and dichlorobiphenyls. The SPP-BP membrane with an optimized m-biphenylene/p-biphenylene ratio (i.e., 4 : 1) for a hydrophobic moiety exhibits outstanding chemical stability as well as high proton conductivity.