EPDM rubber-reinforced PA6/EVOH composite with enhanced gas barrier properties and injection moldability for hydrogen tank liner

Polymeric liners, one of the main components of hydrogen tanks, have attracted significant research interest because of their lightweight and high-impact strength. Despite their advantages, high gas permeability limits their applications. Thus, numerous studies have been conducted to improve the gas barrier properties of polymer-based composites. In this study, we used a polyamide 6 (PA6)/ethylene vinyl alcohol (EVOH) blend as a matrix for high hydrogen gas barrier properties and ethylene propylene diene monomer (EPDM) rubber as reinforcement for injection moldability. The ternary polymer blends were successfully injection molded, and their morphology, mechanical properties, and gas permeability were measured. In addition, we performed a rheological investigation to analyze the processability of the ternary polymer blends. As a result, the developed material system showed a 28% reduction in hydrogen permeability and a 11% improvement in tensile strength compared to a commercial material. This study will be a valuable resource for the research of polymeric liners with efficient and reliable performance.