Abstract
High-pressure hydrogen gas seal is one of key technologies for realization of hydrogen energy system. It is important to understand the durability of high-pressure gas seal. Ethylene-propylene rubber (EPDM) and acrylonitrile-butadiene rubber (NBR) composites filled with carbon black, silica, and unfilled composites were exposed to high-pressure hydrogen gas. The addition of carbon black raised the hydrogen content of the composite, while the addition of silica did not. The blister fracture of composites with silica was less pronounced, irrespective of the hydrogen pressures. This can be attributed to their lower hydrogen content and higher strength than the others. In order to evaluate the influence of hydrogen pressure and operation condition on durability of sealing rubber materials under high-pressure hydrogen gas, a durability tester which enables the sealing rubber to apply high pressure hydrogen gas pressure at arbitrary test conditions was developed. Durability and hydrogen permeation properties of vulcanized EPDM composite filled with white reinforcing filler were evaluated. In the case of maximum pressure of 35 MPa and 70 MPa at 100°C, O-ring was highly damaged in terms of blister fracture and overflow fracture. Overflow fracture is originated from volume inflation of the rubber material in the O-ring groove.
