Service life estimation of liquid silicone rubber seals in polymer electrolyte membrane fuel cell environment

Polymer electrolyte membrane fuel cell (PEMFC) is a promising power source for many applications such as automobiles. Sealing around the perimeter of the cell is required to prevent the gases/liquids inside the cell from leaking and polymers are usually used for the seal or gasket materials. They in general possess the viscoelastic property which induces stress relaxation of the material under constant strain. The stress relaxation behavior of liquid silicone rubber, a type of polymer used as seals in PEMFCs, is studied in this work. A Prony series is used to predict the compression stress relaxation curve at different strain levels. Applying the time–temperature superposition, master curves are generated and used for predicting the service life of this material as seals in PEMFCs. The estimated lives in water and in air are compared.