Studies on Modification of Polyamide 6 Plastics for Hydrogen Storage

Polyamide 6 (PA6) can be used as the liner material of a type IV hydrogen storage tank, but its high hydrogen permeability and poor low-temperature toughness limit its application in related fields. In this work, PA6 composites were prepared by introducing graphene with different contents and a nano two-dimensional lamellar filler via the melt blending method, and the effects of the graphene content on the crystallization properties, mechanical properties, and hydrogen barrier properties of the composites were investigated. The results showed that composites containing 2.0 wt% graphene exhibited the best overall performance, and compared with PA6, the crystallization properties, normal-temperature impact strength and low-temperature impact strength of the composites were increased by 16.0%, 130.6% and 111.7%, respectively, and the helium permeability coefficient was decreased by 33.2%. Graphene enhances the crystallinity and lamellar thickness of the composites. Additionally, its two-dimensional lamellar structure can also increase the diffusion path of gas molecules, thereby improving the barrier properties of the composites.