Polybenzimidazoles with Pendant Quaternary Ammonium Groups as Anion Exchange Membranes: Synthesis, Characterization and Alkaline Stability

摘要

A novel method for introducing quaternary ammonium-bearing side chains has been developed and applied to a polybenzimidazole backbone to generate new anionic-exchange polymers, TMHA-m-FPBI where m = the degree of substitution of available sites (values ranging from 74 to 100%). These polymers have been shown to exhibit hydroxide ion conductivities up to 34 mS cm~(-1) in hydrated membranes at ambient temperature and 13 mS cm~(-1) at 60 °C, RH = 95%. Immersion of these polymers in 2 M KOH at 60 °C has shown they remain stable with no sign of chemical structure degradation to a period of at least 15 days.