Accelerated Test of Silicone Rubbers Exposing to PEMFC environment
Daijun Yang, Jingwen Ma, Qing Zhang, Bing Li, Pingwen Ming, Cunman Zhang
Abstract
The durability of sealing material is one of the major challenges to the overall lifetime of proton exchange membrane fuel cell (PEMFC). In order to study the failure mode and aging mechanism of fuel cell seals, this paper focuses on the most widely used commercial silicone rubber, and an ex-situ accelerated aging method was employed by simulating the circumstance of PEMFC, including higher temperature and clamping force, lower pH value and F− with higher concentration. The main factors that affect the performance of the seal were obtained through the test of their morphologies and mechanical properties. The failure mode of the aging mechanism of the rubbers were analyzed through scanning electron microscopy (SEM), energy dispersive spectrometer (EDS), attenuated-total-reflection infrared spectroscopy (ATR-IR), mass loss, compression set (CS), etc. It was found that temperature played an important role in the deterioration of seal performance, and the change of the parameters of the compression set with time conformed the dynamic empirical formula, which provides the experimental basis for the lifetime prediction of the seals.