光氧老化对聚丙烯长丝蠕变行为的影响

分别在室内环境及人工加速老化条件下对聚丙烯长丝进行恒定载荷作用下的蠕变实验，在同样的外载荷作用下，受到紫外辐射的作用而发生光氧老化的聚丙烯长丝，其蠕变速率系数有所增大；恒定载荷越大，紫外辐射对材料蠕变的影响越明显；有紫外辐射情况下，恒定载荷大小对蠕变的影响也会变得明显。对不同蠕变时间的聚丙烯长丝进行强力和粘度测试，观察其蠕变过程中性能的变化情况，发现断裂强力和相对分子质量均有所降低，说明在紫外辐射作用下，材料发生光氧老化反应，大分子的降解使微观结构发生改变，导致断裂强力及蠕变行为的变化。

Influence of Photo-oxidation on Creep Behavior of Polypropylene Filaments

Creep experiments of polypropylene filaments under different loads are made both in door and in accelerated degradation conditions. Creep of the filaments is influenced by loading levels; The UV radiation can accelerate the creep rate; The influence of photo-oxidation on creep becomes more obvious under higher load levels, and the influence of load level on creep becomes more obvious with photo-oxidation. The intensity and molecular weight tests of polypropylene filaments of different creep time are undertaken to describe the change of filaments' properties. It is concluded that the change of microstructure and properties under photo-degradation makes the change of creep behavior of polypropylene filaments.