Synergistic crosslink of double bond and nitrile group of nitrile rubber in H2S environment

This study investigated the corrosion test of nitrile-butadiene rubber (NBR) in H2S. Butadiene rubber (BR) and hydrogenated nitrile-butadiene rubber (HNBR) were used to simulate the structural units of 1,4-polybutadiene and polyacrylonitrile in NBR. The characterizations of infrared spectra, CHNS elemental analysis, and XPS may indicate that when double bonds and nitrile groups coexist, NBR has the highest reactivity with H2S and crosslinks of monosulfur and disulfide appear inside the rubber. However, the reactivity of BR and HNBR was reduced and no crosslinking was produced when both were isolated. Therefore, double bonds and nitrile groups have a synergistic effect in the H2S environment.