Pyridine containing aromatic polyether membranes

Abstract

The chapter describes the development of aromatic poly(ether sulfone)s carrying main chain pyridine units as alternative to poly(benzimidazole) (PBI) polymer electrolytes for high temperature polymer electrolyte membrane fuel cell (HT-PEMFC) applications operating at 180°C. These polymeric materials present excellent thermal and oxidative stability both ex situ and in situ as well as high proton conductivities after doping with strong protic acids. The pathway from monomers' design to polymerization conditions optimization and finally to membranes preparation and doping with phosphoric acid is analytically presented. Further structural and mechanical stabilization of such polyelectrolytes and their application in HT-PEMFCs operating above 180°C even up to 220°C has been achieved through cross-linking. The cross-linked materials superiority over linear analogues is depicted.