Fuel-Cell Performance of Multiply-Crosslinked Polymer Electrolyte Membranes Prepared by Two-Step Radiation Technique

Radiation grafting is an attractive method of preparing polymer electrolyte membranes for proton exchange membrane fuel cells (PEMFCs). In this technique, the addition of monomers with two or more vinyl groups, called chemical crosslinkers, to a reaction monomer solution bridges and links the grafted polymer chains together, thereby reducing fuel/gas permeability of the membranes and improving their stability and fuel cell performance. Bifunctional divinylbenzene (DVB) is the most frequently used chemical crosslinker [1]. A JAEA group has independently been using radiation-crosslinked polytetrafluoroethylene (cPTFE) films for grafting of styrene or its derivatives [2]. This provides the first successful example of the membranes composed of the crosslinked perfluorocarbon main chain