Abstract
Proton Exchange Membranes (PEM) in Membrane electrode assemblies (MEA) in polymer electrolyte fuel cells is major concern for fuel cell vehicles. Hygro-thermal cyclic conditions induce the mechanical stress in MEA and cracks are formed under operating conditions. Chemical degradation of PEM is caused by radical attack. The purpose of this paper is to understand the mechanical characteristic of chemically damaged PEM. We carried out tensile tests for PEM degraded by Fenton reaction. For tensile tests, PEM was immersed in hydrogen peroxide solution containing the iron ions. The tensile tests revealed that by Fenton reaction, the yield stress and the modulus of longitudinal elasticity of PEM was increased and the breaking strain was decreased. This result indicates that PEM property is changed by suffering chemical damage. It is concluded that chemically damaged PEM is stiffer and more brittle than undamaged one.
