Host: The Japan Society of Mechanical Engineers
Name : [in Japanese]
Date : September 08, 2024 - September 11, 2024
In this study, we aimed to clarify how the frictional properties of EPDM changed after water immersion by treating it with plasma to promote decrosslinking. Three types of rubber were prepared as rubber test pieces for friction tests: untreated vulcanized EPDM rubber, vulcanized EPDM rubber plasma-treated with argon gas only, and vulcanized EPDM rubber plasma-treated with a mixture of hydrogen and argon gas. Ball-on-disk friction tests were performed against a SUJ-2 ball after and without water immersion . As a result, the friction coefficients of all EPDM test pieces after water immersion were lower than those without immersion. However, the friction coefficients of the two test pieces, which showed almost no change in swelling ratio due to plasma treatment, changed significantly after waterimmersion . Specifically, the swelling ratios of untreated EPDM and EPDM treated with argon plasma were not significantly different at 210% and 214%, respectively, but the friction coefficients of the two test pieces after water immersion were significantly different at 1.23 and 0.35, respectively. Because the friction coefficient changes significantly depending on whether or not plasma treatment is performed, it is difficult to draw quantitative conclusions from the results of this experiment alone about how the degree of decrosslinking of EPDM affects the friction coefficient after immersing EPDM in water.
