Abstract
Experimental evidences regarding the sulfonation of polyoxadiazole and oxadiazole–triazole copolymers during the preparation are given. The structures of the polymers were qualitatively and quantitatively characterized by elemental analysis, 1H NMR, and FTIR. Polymers with high molecular weights (up to 470,000 g/mol) exhibiting highly oxidative stability are obtained allowing the casting of mechanically stable membranes with high storage modulus (about 4 GPa at 100 °C) and high proton conductivity values (order of magnitude of 10−2 S cm−1 at 80 °C).