Synthesis and Proton Conductivity Studies of 5-Aminotetrazole-Doped Sulfonated Polymer Electrolyte Membranes

This work reports the preparation and characterization of a new anhydrous proton conducting membrane based on poly(vinyl alcohol) (PVA), sulfosuccinic acid (SSA), and 5-aminotetrazole (ATet) at various stoichiometric ratios. The proton conductivities of membranes were investigated as a function of ATet composition, SSA composition, and temperature. New anhydrous proton conducting membranes were characterized by infrared spectra, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), methanol permeability, and impedance measurements for proton conductivity. TGA showed that the samples were thermally stable up to 150 degrees C. DSC results illustrated the homogeneity of the materials. Mechanical analysis showed that the storage modulus of the PVA-SSA-ATet blend polymer membranes decreased with increasing ATet content. The membranes with higher tetrazole content, or higher acid doping level presented the higher proton conductivity. PVA-SSA-ATet4 can exhibit an anhydrous proton conductivity of 1.7 x 10(-3) S/cm at 130 degrees C and the proton conductivity increased with increasing temperature and acid doping level. POLYM. COMPOS., 32:1625-1632, 2011. (C) 2011 Society of Plastics Engineers