Synthesis and characterization of new sulfonated copolytriazoles and their proton exchange membrane properties

Abstract

ABSTRACTThis work reports the synthesis and characterization of a series of new sulfonated copolytriazoles. The polymers were prepared by CuI catalyzed 1,3‐cycloaddition reaction of an equimolar amount of a dialkyne monomer, 1,3‐diethynylbenzene and a mixture of two diazide monomers, namely, 4,4′‐diazidodiphenyl ether and 4,4′‐diazido‐2,2′‐stilbenedisulfonic acid disodium salt. The copolymers showed high inherent viscosity indicating the formation of high molar mass product. The copolymers were characterized by Fourier transform infrared and proton nuclear magnetic resonance spectroscopic techniques. The copolymer membranes displayed moderate water uptake, high dimensional, mechanical, and thermal stability. Transmission electron microscopy micrographs displayed excellent phase‐separated morphology along with very fine ionic clusters. The copolymer PTEOSH‐90 (90% degree of sulfonation) showed much higher proton conductivity value which is up to 196 mS cm−1 at 80 °C in completely hydrated condition compared to that of Nafion (165 mS cm−1). © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48514.