摘要
The degradation of hydrogenated nitrile-butadiene rubber(HNBR) soaped in aqueous solutions of HzS and HC1 was investigated, The samples unexposed and exposed to different solutions were characterized by 13C nuclear magnetic resonance(~3C NMR), X-ray photoelectron and infrared spectroscopies. In contrast to those of unexposed samples and samples soaped in HCI solution, the mechanical properties of samples exposed to H2S solution signifi- cantly 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 HC1 solution. The formation of C--S--C was due to radical reaction in- itiated 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 cnvironment containing H2S.
The degradation of hydrogenated nitrile-butadiene rubber(HNBR) soaped in aqueous solutions of HzS and HC1 was investigated, The samples unexposed and exposed to different solutions were characterized by 13C nuclear magnetic resonance(~3C NMR), X-ray photoelectron and infrared spectroscopies. In contrast to those of unexposed samples and samples soaped in HCI solution, the mechanical properties of samples exposed to H2S solution signifi- cantly 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 HC1 solution. The formation of C--S--C was due to radical reaction in- itiated 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 cnvironment containing H2S.
基金
Supporter by the National Natural Science Foundation of China(No.51003121) and the Cultivation Fund of the Key Scien- tific and Technical Innovation Project, Ministry of Education of China(No. 707010).