丁腈橡胶热氧老化与防护的研究进展及反应机理探讨

Research progress and discussion on reaction mechanism of thermal oxidation aging and protection for nitrile rubber

综述了国内外丁腈橡胶(NBR)热氧老化及防护的研究进展,探讨了NBR热氧老化及2种防护类型的化学反应机理。NBR生胶热氧老化后使得分子链断裂生成带有醛、酮等基团的聚合物,并产生HCN、NH_3等小分子化合物。胺类是抗热氧老化最佳的链终止型防老剂,酚类、烷基苯基亚磷酸酯类和硫酯类化合物的单一组分或复合体系是破坏氢化过氧化物型防老剂,硫酯类防老剂具有高效的抗热氧老化效果。

The research progress of thermal oxida- tion aging and protection for nitrile rubber were re- viewed with 17 references, the thermal oxidation re- actions and the chemical reaction mechanisms of two kinds of protection were discussed. After thermal oxidation aging of nitrile rubber , the ldehyde and ketone groups were formed when the polymer chain was broken, meanwhile, some small molecules such as HCN, NHa generated. The antioxidants as amines, phenols, alkyl phenyl phosphite esters and thioesters compounds, used singlely or mixed in ni- trile rubber, were effectively to termminate chain radicals and destruct hydrogen peroxide. Thioesters was more effetive for antioxidation.