Polyaniline/polybenzimidazole blends: Characterisation of its physico-chemical properties and gas separation behaviour

Novel polymer blends were prepared by casting blend solutions, of polyaniline (PANI) and polybenzimidazole (PBI) at various ratios. Prepared blends were amorphous and had good film homogeneity without defects. From mechanical analysis it was found that tensile strength diminishes with increasing content of PANI. WAXS analysis disclosed the amorphous structure of PANI/PBI blends. IR spectra indicate clearly the presence of PANI in PEI matrix and NMR spectra revealed significant interactions of PEI with PANI. Permeability, diffusion, solubility coefficients and sorption capacities of all measured gases (H-2, O-2, CH4, N-2, CO2 and water vapour) decreased with increasing PANI content whereas ideal selectivities increased for all observed gas pairs. Doping of blends with hydrochloric acid led to a significant decrease in permeabilities and sorption capacities while selectivities slightly increased. (C) 2016 Elsevier Ltd. All rights reserved.