Interaction between swelling behavior and erosion resistance of nitrile-butadiene rubber vulcanizates in sodium chloride solution

Abstract

Static swelling experiment and erosion test were performed to investigate the effect of seawater on the tribological behavior of nitrile-butadiene rubber with different acrylonitrile contents (18 wt%, 26 wt% and 41 wt%). After 7 days swelling, the mass change fraction in deionized water were from 1.25 to 1.43 times higher than that in sodium chloride solution. The specimen hardness decreased with the increasing of swelling time in deionized water, however it increased in sodium chloride solution. The erosion rate showed an increasing tendency with the swelling time, its growth proportions were from 84.8% to 114.9% in deionized water, and from 111.7% to 156.4% in sodium chloride solution. To further reveal the swelling effects on the tribological properties, the transformation of surface composition of swollen specimens and the morphologies of worn surfaces were analyzed, the mechanism of the interaction between swelling and erosion was also discussed.