Phosphonic acid functionalized proton exchange membranes for PEM fuel cells

The sulfonic acid functionality has dominated as the ion-exchange component of virtually all polymeric materials that have been developed and commerci alized for application as membranes in proton exchange membrane fuel cells (PEMFC). Over the years, phosphonic acid functionalized polymers have been proffered as potential candidates to augment the arsenal of available mater ials for use in PEMFC. This paper explores the synthesis of poly(trifluoros tyrene)-based ionomers which contain as their ion-exchange functionality th e phosphonic acid grouping, Preparative details, materials characterization and early indications of fuel cell performance capabilities for these nove l ionomers are discussed.