Polybenzimidazoles with Enhanced Basicity: A Chemical Approach for Durable Membranes

A major issue of polybenzimidazole (PBI)-based membranes is the leaching loss of the doping acid during fuel cell operation. In this chapter, two approaches to improve the conductivity and its stability are presented by tailoring the polymer basicity: (a) modification of the polymer backbone by synthesis of new monomers and (b) fabrication of (nano)composite membranes with functionalized fillers. Chemical modification of the polymer backbone is likely the strategic choice for its significant effect, simplicity, reproducibility and cost.