Research on hydrogen permeability of polyamide 6 as the liner material for type Ⅳ hydrogen storage tank

As the liner material of type IV hydrogen storage tank, polymer is restricted in commercial application due to its high hydrogen permeability. In this paper, for the first time, the suitability of polyamide 6 (PA6) filled with lamellar inorganic components (LIC) as the hydrogen storage tank liner is comprehensively investigated, including thermal and mechanical properties, morphology and structure, rheology, and the hydrogen permeability under various temperature (−10 °C, 25 °C, 85 °C) and pressure (25 MPa, 35 MPa, 50 MPa) conditions. The results show that comparing with PA6, the thermal and processing properties of LIC/PA6 have been improved, the tensile strength, bending strength and bending modulus of LIC/PA6 are increased by 36%, 17% and 12%, respectively. Especially, the hydrogen permeability of LIC/PA6 is decreased by 3–5 times which meets the requirements specified by the hydrogen tank standard. The research work provides a theoretical basis and reference for the preparation and selection of high barrier liner materials in the future.