On the doping of sulfonated polybenzimidazole with strong bases

摘要: Abstract Grafting of (4-bromomethyl)benzenesulfonate onto polybenzimidazole (PBI) leads to a proton exchange polymer variable degree sulfonation. At high degrees sulfonation, the membranes display phenomenon dehydration and contraction, which is shown be due presence chain cross-linking strong hydrogen bond network. Immersion form benzylsulfonate-grafted in aqueous organic or inorganic base sufficient disrupt this network, lead rehydration return swollen flexible state, base-doped N -benzylsulfonate-grafted PBI (PBI–BzSH) have conductivity 2×10 −2 S cm −1 at 25°C 100% relative humidity. Exchange sodium with H + takes place three points neutralisation, pH range 5.5–12.4, exists predominantly zwitterionic form.