纳米TiO_2、纳米ZnO对聚丙烯抗紫外光老化及结晶性能的影响

The UV Ageing Resistance and Crystallization of PP/Nano-TiO_2 or Nano-ZnO Composites

借助DSC、FT-IR、DM A现代分析表征技术,首次以马来酸酐接枝聚丙烯作为聚丙烯/纳米T iO2或纳米ZnO复合材料的相容剂和相分散剂,系统研究了它们对聚丙烯的耐紫外光老化性能的影响,同时,探讨了纳米T iO2和纳米ZnO对聚丙烯的结晶成核作用。研究结果表明,纳米T iO2、纳米ZnO的加入使PP的β-晶型熔融峰消失,对聚丙烯结晶有明显的成核促进作用;随着紫外光老化时间的延长,PP熔融峰高度下降,峰宽和熔融温度基本不变,1750 cm-1处的峰面积增加幅度减小;纳米T iO2和纳米ZnO可以减缓PP在紫外光照射下的降解速度,提高PP对外界能量的耗散作用;PP纳米复合材料的损耗模量明显增大,阻尼因子(即tanδ)在添加PP-g-M AH后峰值也明显下降。

By using of the melt-extrusion processing, DSC, FT-IR, DMA analysis and maleic anhydride grafted-polypropylene （PP-g-MAH） as the compatibilizer and dispersion agents, the UV ageing-resistance and crystallization of PP/nano-TiO2or nano-ZnO composite has been studied systematically. Furthermore, it is found that the nano-TiO2 and nano-ZnO can promote crystallization of polypropylene in the composites, the β-form of crystal has disappeared with increasing of nano-TiO2 and nano-ZnO. With the UV ageing time going, PP crystal melting peak-height in DSC is decreased, the increasing amounts of peak area is decreased, width and temperature point of the peak is almost unchanged. PP＇ UV ageing degradation speed is decreased, the modulus is increasing with addition of nano-TiO2 and nano-ZnO, and damping factor （tanδ） is decreased with addition of PP-g-MAH. All the results provide us the theoretical and experimental basis of developing new nano-inorganic UV ageing-resistance agents for polymer materials.