In this study, degradation of silicone rubbers with different hardness exposed to various aqueous solutions was investigated.
Considering the elastic properties required for practical fuel cell applications [8], three silicone rubbers with Shore hardness of 30, 40, and 50 were selected. It turned out that the degradation of silicone rubbers could result in weight loss and voids or cracks on the surface of tested materials because of the chemical decomposition of silicon based backbone and leaching of fillers.
With the increase in hardness, silicone rubbers became more durable in tested aqueous solutions. The results described here may provide guidance for evaluation or selection of silicone rubbers as seals for PEMFC applications.