Degradation of hydrogenated nitrile-butadiene rubber in aqueous solutions of H2S or HCl

作者:Cong Chuan-bo; Cui Can-can; Meng Xiao-yu; Lu Shao-jie; Zhou Qiong*
来源:Chemical Research in Chinese Universities, 2013, 29(4): 806-810.
DOI:10.1007/s40242-013-2401-7

摘要

The degradation of hydrogenated nitrile-butadiene rubber(HNBR) soaped in aqueous solutions of H2S and HCl was investigated. The samples unexposed and exposed to different solutions were characterized by C-13 nuclear magnetic resonance, X-ray photoelectron and infrared spectroscopies. In contrast to those of unexposed samples and samples soaped in HCl solution, the mechanical properties of samples exposed to H2S solution significantly deteriorated, in which the new groups of C(=O)-NH2, C-S-C and C=S emerged. The mechanism of C=S and C-S-C formation was speculated, except for that of the formation of group C(=O)-NH2, which was widely discussed in acidic condition such as HCl solution. The formation of C-S-C was due to radical reaction initiated by mercapto radical and that of C=S was due to nucleophilic reaction initiated by mercapto cations. This finding is helpful to understanding the seal failure of HNBR in working environment containing H2S.