应力作用下的PP光氧降解行为研究

Study on Photooxidative Degradation Behavior of Polypropylene under Tensile Stress

通过在应力作用下的光氧加速老化的方式,对聚丙(烯PP)的光氧降解行为进行了研究。利用GPC、XPS、SEM、WAXD及力学性能测试等手段考察了应力对PP光氧降解过程中微观结构和宏观性能的影响。结果表明:当应力低于临界应力时,随着应力的增加,PP的光氧老化随之加速;高于临界应力时,随着应力的增加,PP的光氧老化反而得到抑制;当在更高的温度时,以上现象更为明显。在PP的老化过程中,力学性能都是逐渐降低的。

The photooxidative degradation behavior of PP was studied by accelerated aging under stress. The influences of stress on microstructure and macroscopic properties of PP during the photooxidative degradation were studied by GPC 、XPS 、SEM 、WAXD analysis and mechanical properties test.The results show that：when the tensile stress is within the region of critical stress,the photooxidative degradation of PP increases significantly with the increasing of stress;when the tensile stress is above critical stress,the photooxidative degradation of PP decreases significantly with the increasing of stress;when at the higher temperature,the above phenomenon is more obvious.During the aging process of PP sample,the mechanical properties decrease gradually.