Solid State Ionics, Vol.97, No.1-4, 323-331, 1997
Synthesis and Characterization of Sulfonated Polybenzimidazole - A Highly Conducting Proton-Exchange Polymer
Grafting of sulfonated aryl groups on to polybenzimidazole, PBI, leads to a proton conducting polymer. The synthetic route allows close control of the degree of sulfonation, and a range of samples have been prepared with degrees of sulfonation up to 75% of the available sites. Sulfonation increases the conductivity from ca. 10(-4) S cm(-1) in non-modified PBI to > 10(-2) S cm(-1) at room temperature for highly sulfonated samples. The dependence of the conductivity both on the degree of sulfonation and on the conditions of membrane preparation are discussed.