HYDROGEN TRANSPORT AND FAILURE OF RUBBER SEALING MATERIALS IN HIGH-PRESSURE HYDROGEN: A REVIEW OF CHARACTERIZATION, COMPATIBILITY, AND FAILURE-RESISTANT DESIGN

ABSTRACT Rubber seals in high-pressure hydrogen systems undergo coupled gas transport, deformation, damage, and leakage during pressurization and decompression. Delayed hydrogen release may cause swelling, rapid gas decompression damage, cyclic cracking, interfacial degradation, and seal failure. This review links hydrogen uptake and transport with swelling, damage evolution, and seal-level performance. Diffusivity, solubility, and permeability are discussed together with pressure, temperature, exposure time, decompression path, cycling history, specimen geometry, and formulation. Desorption analysis, microscopic characterization, in situ swelling observation, leakage testing, and coupled simulation are compared according to their outputs and limitations. Representative quantitative data are summarized with their test conditions, whereas NBR, HNBR, EPDM, fluoroelastomer, vinyl methyl silicone rubber, and emerging composite systems are interpreted within condition-bounded service windows. Matrix regulation, filler design, coatings, and barrier-toughening strategies are also reviewed. Reliable material selection requires linking specimen-scale transport and swelling with damage, leakage, and actual seal durability.