An investigation of proton conductivity of binary matrices sulfonated polysulfone/polyvinyltriazole after doping with inorganic acids

Abstract

As anhydrous proton conductive membranes, sulfonated polysulfone (SPSU) and polyvinyl triazole were studied as binary matrices. The sulfonation of polysulfone was performed with trimethylsilylchlorosulfonate and high degree of sulfonation (140%) was obtained. Ion exchange capacity of SPSU was determined as 3.05 mmol−1/g. The polymer electrolyte membranes were prepared by blending of sulfonated polysulfone with polyvinyl triazole and phosphoric acid. Fourier transform infrared spectroscopy confirmed the sulfonation of the polysulfone and the ionic interaction between sulfonic acid and triazole units. Thermogravimetric analysis showed that the polymer electrolyte membranes are thermally stable up to at least 150°C. Scanning electron microscopy analysis indicated the homogeneity of the ternary composites. The maximum proton conductivity has been measured as 3.63 × 10−4 S cm−1 at 150°C.