垫片材料在模拟的PEM燃料电池环境下损伤机制

Degradation mechanism of gasket material in simulated PEM fuel cell environments

垫片材料化学性能长时间的稳定性对质子交换膜(PEM)燃料电池密封及其性能至关重要。采用实验的方法研究PEM燃料电池垫片常用材料-硅橡胶材料在模拟的PEM燃料电池环境下的损伤情况。使用2种模拟的PEM燃料电池环境,采用X线光电子能谱(XPS)技术研究弹性体垫片材料暴露在模拟的PEM燃料电池环境下的损伤机制。试验结果表明,垫片材料暴露在PEM燃料电池环境下材料表面的化学结构发生了明显的变化,材料损伤机制主要是硅橡胶材料主链Si—O—Si和侧链Si—CH3逐渐断裂所致。

The long-term chemical stability of gasket materials was critical to both sealing and electro- chemical performance of proton exchange membrane （PEM） fuel cell. The chemical degradation of sili- cone rubber material, which was widely used as gasket material in PEM fuel cells, was investigated experimentally in simulated fuel cell environments. The degradation mechanism of gasket material in simulated fuel cell environments was studied by X-ray photoelectron spectroscopy （XPS） technique. Results indica- ted that the chemical structure on material surface changed significantly and degradation caused mainly by chain scission in the backbone of Si--O--Si and side group of Si-CH3.