EPDM/PP热塑性弹性体在循环应力下的老化行为研究

本文研究了动态硫化EPDM/PP热塑性弹性体的动态疲劳老化行为,考察了其力学性能的变化,并分析了产生力学性能下降的原因。实验结果表明,随着疲劳时间的延长、疲劳振幅的增大,材料的断裂强度降低,并认为疲劳过程中完全硫化的EPDM橡胶粒子和热塑性塑料PP界面处的分子链断裂、滑移导致了断裂强度的降低;紫外光的加入,加速了材料在疲劳过程的分子链断裂、滑移速率,使材料的断裂强度有更大程度的降低;在机械疲劳老化单独作用下,材料体系几乎没有发生氧化反应,而紫外光的加入,促使了机械疲劳老化过程中氧化反应的发生。

Study of the aging behavior of EPDM/PP thermoplastic elastomers under cyclic stress

In this article,the aging behavior of the dynamically vulcanized EPDM/PP thermoplastic elastomers under cyclic stress was investigated,the change of the mechanical properties was inspected,and the reason of the changes was explored.The results shows that the breaking strength decreased with the extension of fatigue time and the increase of the fatigue amplitude,and the diminution of the breaking strength was attributed to the chain fracture and chain slip at the interface of the thermoplastic PP and EPDM rubber particles.With the addition of UV,that accelerated the chain fracture and chain slip under the mechanical fatigue process,the breaking strength has a greater decrease.With the action of the mechanical fatigue aging alone,little oxidation reaction occurred,but with the addition of UV,there were oxidation reactions during the mechanical fatigue aging process.