Proton-conducting blend membranes of crosslinked poly(vinyl alcohol)-sulfosuccinic acid ester and poly(1-vinyl-1,2,4-triazole) for high temperature fuel cells

New type of composite membranes were synthesized by crosslinking of poly(vinyl alcohol) (PVA) with sulfosuccinic acid (SSA) and intercalating poly(1-vinyl-1,2,4-triazole) (PVTri) into the resulting matrix. The complexed structure of the membranes was confirmed by Fourier transform infrared (FTIR) spectroscopy. The resulting hybrid membranes were transparent, flexible, and showed good thermal stability up to similar to 200 degrees C. The proton conductivities of the membranes were investigated as a function of PVTri and SSA and operating temperature. The water/methanol uptake was measured and the results showed that solvent absorption of the materials increased with increasing PVTri content in the matrix. The proton conductivity of the membranes continuously increased with increasing SO3H content, PVTri content, and the temperature. In the anhydrous state, the maximum proton conductivity is 7.7 x 10-5 S/cm for PVASSAPVTri-1 and for PVASSAPVTri-3 is 1.6 x 10-5 S/cm at 150 degrees C. After humidification (RH = 100%), PVASSAPVTri-4 showed a maximum proton conductivity of 0.0028 S/cm at 60 degrees C. POLYM. ENG. SCI., 2013. (c) 2012 Society of Plastics Engineers