Influence of Fillers on Hydrogen Penetration Properties and Blister Fracture of EPDM Comosites Exposed to 10 MPa Hydrogen Gas

EPDM composites with carbon black (CB 50, CB25), with silica (SC60), and without fillers (NF) were exposed to 0.6 to 10 MPa hydrogen gases at 30°C, and the influence of fillers on hydrogen content and blister fracture of EPDM composites was investigated. The hydrogen contents of CB 50, CB 25, SC 60, and NF were proportional to hydrogen pressures up to 10 MPa. It is confirmed that the behavior of their hydrogen contents follows Henry's law. The addition of the carbon black raised the hydrogen content of EPDM composites, while the addition of the silica did not raise that of EPDM composites. With respect to diffusivity, the carbon black lowered the diffusivity of EPDM compos-ites, while the silica hardly influences that of EPDM composites. According to the observation of blister damages of CB 50, CB 25, SC 60, and NF, the blister damage of SC 60 is the slightest. It is considered to be due to lower hydrogen content and relatively better tensile properties compared with the others.