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.