The Effect of Dy(III) Complex with 2-Mercaptobenzimidazole on the Thermo-Oxidation Aging Behavior of Natural Rubber Vulcanizates

A novel kind of Dy(III) complex with 2-mercaptobenzimidazole was prepared. The antioxidative properties and mechanisms of the Dy(III) complex in the NR vulcanizates were investigated by attenuated total-reflectance Fourier transform infrared (FTIR-ATR) spectroscopy, crosslinking density determination, mechanical properties testing and thermogravimetric analysis. The thermo-oxidative stability of the NR vulcanizates was found to be improved markedly by the addition of Dy(III) complex. It can be attributed to the thioether bonds, which can decompose the hydroperoxide, and the Dy(III) ions, which can capture and inactivate the oxy radicals. The apparent thermo-oxidation activation energy of the NR vulcanizates was calculated by the Kissinger and Flynn-Wall-Ozawa methods, respectively. The results show that the NR vulcanizates with the Dy(III) complex have higher thermo-oxidation activation energy than that of the samples with antioxidant MB and antioxidant 4010NA.