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This review aims to synthesize knowledge on how high-pressure hydrogen influences elastomeric sealing materials and their performance.

May 16, 2026Open Access

Hydrogen Transport, Viscoelastic Drift, and Multiscale Characterization Framework for Elastomeric Seals Under High-Pressure Hydrogen

Key Points

This review aims to synthesize knowledge on how high-pressure hydrogen influences elastomeric sealing materials and their performance.
Compiles experimental results for common elastomers like NBR, HNBR, FKM, EPDM, and silicone.
Summarizes hydrogen diffusivity, solubility, and permeability ranges under high-pressure conditions.
Compares transport characteristics with mechanical and microstructural observations from DMA, NMR, decompression testing, and µXCT imaging.
Hydrogen-induced changes are mostly due to physical processes such as swelling and mobility changes, rather than extensive chemical degradation.
Elastomers with similar mechanical properties can show varying hydrogen uptake and viscoelastic responses.
Time-dependent viscoelastic evolution is crucial for assessing sealing performance, which traditional mechanical tests may overlook.

Abstract

High-pressure hydrogen exposure may induce transport and diffusion–relaxation–controlled changes in elastomeric sealing materials that differ from conventional fluid aging. Hydrogen uptake through solution–diffusion processes can lead to swelling, redistribution of molecular mobility, viscoelastic evolution, and, under certain conditions, cavitation or microvoid formation during decompression, which may affect long-term sealing performance. This review compiles experimental results for commonly used elastomers, including Nitrile Butadiene Rubber (NBR), hydrogenated nitrile butadiene rubber (HNBR), Fluoroelastomer (FKM), Ethylene Propylene Diene Monomer (EPDM), and silicone, and summarizes reported ranges of hydrogen diffusivity, solubility, and permeability under high-pressure conditions. These transport characteristics are compared with mechanical and microstructural observations obtained from Dynamic Mechanical Analysis (DMA), Nuclear Magnetic Resonance (NMR), decompression testing, and micro-computed tomography (µXCT) imaging. Available evidence suggests that hydrogen-induced changes are predominantly governed by physical processes, including swelling, plasticization-like mobility changes, and constraint redistribution, while extensive chemical degradation of the polymer backbone is generally limited under clean hydrogen conditions. Materials with similar conventional mechanical properties may, therefore, exhibit different hydrogen uptake, viscoelastic response, and resistance to decompression damage. Conventional single-point mechanical tests, such as tensile measurements, may not fully capture the time-dependent viscoelastic evolution relevant to sealing performance. This work proposes a multiscale characterization framework integrating transport, viscoelastic, molecular, and microstructural analysis for more reliable evaluation of elastomers in hydrogen service, supporting improved qualification strategies for high-pressure hydrogen systems.

Hydrogen Transport, Viscoelastic Drift, and Multiscale Characterization Framework for Elastomeric Seals Under High-Pressure Hydrogen

Key Points

Abstract

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