反应型大分子抗氧剂的合成及其在EPDM中的抗氧化性能

通过自由基引发的三羟甲基丙烷三甲基丙烯酸酯（TMPTMA）与2?巯基苯并咪唑（MB）反应合成了一种反应型大分子抗氧剂TMPTMA/MB。通过傅里叶变换红外光谱、X射线光电子能谱和元素分析证实了TMPTMA/MB的化学结构，并研究了TMPTMA/MB对EPDM硫化特性、拉伸性能及抗氧化性能的影响，结果表明，TMPTMA/MB消耗了过氧化物分解产生的烷氧自由基并接枝到EPDM分子链上，从而减缓了橡胶的硫化速度并降低了交联程度，但接枝的TMPTMA/MB增加了外力作用下分子链运动的内摩擦，提高了EPDM的拉伸性能，另外，接枝到EPDM分子链的TMPTMA/MB具有较高的抗迁移性，由此大幅提高了EPDM的抗氧化性能。

Synthesis of reactive macromolecular antioxidants and their antioxidation properties in EPDM

A reactive macromolecular antioxidant （hereafter named "TMPTMA/MB"） was synthesized through a free radical?initiated reaction of trimethylolpropane trimethacrylate （TMPTMA） with 2?mercaptobenzimidazole （MB）. The chemical structure of TMPTMA/MB was characterized by using Fourier?transform infrared spectroscopy， X?ray photoelectron spectroscopy， and elemental analysis. The effect of TMPTMA/MB on the vulcanization characteristics， tensile properties， and oxidation resistance of EPDM were investigated. The results indicated that TMPTMA/MB was grafted onto the EPDM molecular chains， followed by consuming the alkoxy radicals generated by the peroxide decomposition. This slowed down the vulcanization rate of the rubber and reduced its crosslinking degree. The grafted TMPTMA/MB enhanced the internal friction of molecular chains under the action of external forces and therefore improved the tensile properties of EPDM. In addition， the TMPTMA/MB grafted on the EPDM molecular chains has high migration resistance， thus improving the oxidation resistance of EPDM significantly.