New benzimidazole-2-yl-substituted polybenzimidazoles: Synthesis, properties, and hydrodynamic characteristics

The synthesis of novel benzimidazole-2-yl-substited polybenzimidazoles and initial compounds has been described. The polymers are studied by FTIR spectroscopy, TGA, and TMA. The hydrodynamic properties of macromolecules are investigated by translational diffusion and viscometry in 96% H 2 SO 4 ; the molecular characteristics of the polymers are determined. Positive temperature dependences for intrinsic viscosities of the polymers are obtained. The polymers under study possess high hydrolytic stability with respect to sulfuric acid solutions up to 150°C and high thermal stability in the bulk. The TGA data correlate with the chemical structure of the polymers. The new polybenzimidazoles may be used as materials for the production of medium-temperature proton-conducting membranes.