Hydrogen Compatibility of Polymers for Fuel Cell Vehicles

So far, hydrogen compatibility of polymer materials was investigated, focusing on gaining insight in general degradation mechanisms. However, this is not yet sufficient for purposes of safety and performance requirements, for example, in the automotive industry and especially, the corresponding advanced material development, which needs meaningful and comprehensive data for prospective long time intervals. Therefore, herein, the applicability of forced aging regimes and the suitability of different analytical techniques for clarification of the underlying mechanisms are focused on. The study analyzes the behavior of polyether ether ketone, (thermoplastic) polyurethane and fluoroelastomer materials after prolonged aging in hydrogen atmosphere under pressure as it occurs in hydrogen fuel-cell vehicles. Material changes are investigated by electron microscopy, thermogravimetry, differential scanning calorimetry, and gas sorption measurements. Especially thermogravimetry turns out to indicate subtle material changes that are important indications for material choice.