纳米二氧化钛催化光降解聚丙烯纤维的研究

在聚丙烯中加入0．3wt％～1．5wt％的锐钛矿型纳米二氧化钛，通过共混熔融纺丝纺制成纤维。通过分析PP／TiO2共混纤维在人工加速紫外光降解和自然光降解过程中拉伸断裂伸长率和表面形态的变化情况，从而研究了共混纤维中锐钛矿型纳米二氧化钛对聚丙烯纤维光氧化降解性能的影响。结果说明，在实验范围内，无论是在253．9nm的紫外光照射的人工加速光降解还是自然光降解过程中，锐钛矿型纳米TiO2的含量越高，聚丙烯纤维试样的断裂伸长率降低速度就越快；同时，紫外光照射纤维试样192小时之后，由SEM照片发现的纤维表面损伤程度也随着其中TiO2含量的升高而越发严重。这说明，锐钛矿型纳米TiO2对聚丙烯的光氧化降解具有明显的催化作用，可以用作聚丙烯的一种高效光敏剂。而且其含量越高，这种催化作用越强。据此，对聚丙烯纤维的光氧化降解可在一定程度上进行调节，从而得到聚丙烯的可控光降解材料。此外，人工加速紫外光降解和自然光降解所得试样的降解规律基本一致，在一般的光老化降解研究中可以用前者代替后者。

Study on Controlled Degradation of Polypropylene

wt%~1.5 wt% of nano-TiO_2 (anatase) were added into polypropylene(PP) to prepare PP/TiO_2 composite, which was spun into fibers. The influence of nano-TiO_2 on photo oxidative degradation of PP in artificial accelerated UV light weathering and natural weathering were studied by mechanical properties monitoring and scanning electronic microscopy (SEM). It is demonstrated that nano-TiO_2 (anatase) shows a photocatalytic effect for the photodegradation of polypropylene in either accelerated or natural weathering experiment and can be a highly effective photosensitizer for it. Thus, the photodegradation of polypropylene can be controlled accordingly and a controlled degradable material of polypropylene can be obtained. In addition, the results gotten from accelerated weathering are roughly the same with those gotten from natural weathering, and the former can replace the latter in some degradation studies.