Mahesh Kulkarni, Ravindra Potrekar, R. A. Kulkarni and S. P. Vernekar
Polybenzimidazoles tethered with various content of pendant phenoxy amine groups, synthesized by the condensation of 3,3'-diaminobenzidine with a mixture of new aromatic diacid, 3,5-dicarboxyl-4'-amino diphenyl ether, and isophthalic acid in different ratio were characterized by different instrumental techniques (FT-IR, TGA, DSC, XRD etc.) and for solvent solubility, mechanical properties and inherent viscosity. These polymers have high thermal stability with initial decomposition temperature 475–506 °C in nitrogen, high glass transition temperatures (Tg) ranging from 313–435 °C and good tensile strength in the range of 58 to 125 MPa. The suitability of these polymers for the application as polymer electrolyte for fuel cell at high temperature on doping with H3PO4 is revealed by their high proton conductivity in the range of 10−3 to 10−2 S/cm.