过氧化物硫化三元乙丙橡胶的高温硫化过程模拟

通过橡胶加工分析仪探讨了采用2种一级唯象动力学方程模拟过氧化物高温硫化三元乙丙橡胶(EPDM)的可行性。结果表明,该模型与实测曲线之间具有良好的相关性,随着硫化温度的升高,过氧化物硫化EPDM橡胶的交联反应程度和断链反应程度均增大,反应速率加快。当温度低于195℃时,交联反应的活化能与断链反应的活化能基本相等;当高于195℃时,交联反应的活化能降低,而断链反应活化能的大小依赖于温度变化。并且发现高温硫化EPDM硫化胶拉伸储能模量(E’)的频率依赖性明显增强,硫化时间长短也会影响分子链的松弛行为。

High Temperature Curing Process Simulation of the Peroxide-Cured Ethylene-Propylene-Diene Rubber

The feasibility of curing process simulation was discussed by two first-order kinetic equations to describe the curing behavior of peroxide-cured ethylene propylene diene rubber (EPDM) by use of rubber process analyzer.The results show that the proposed model has a good correlation with the experimental data.When the curing temperature increases,the cure extent and chain scission increase,both reaction rates increase.When the curing temperature is lower than 195 ℃,the activation energy of cross-linking reaction is mostly equal to one of chain scission reaction.When the curing temperature is higher than 195 ℃,the activation energy of cross-linking reaction.decreases,the activation energy of chain scission reaction changes with curing temperature.Furthermore,the dependence of tensile storage modulus (E') on frequency increases for the EPDM vulcanizates at a higher curing temperature.The curing time also affects the relaxation behavior of chains.