UV ageing resistance and crystallization of PP/Nano-TiO₂ or Nano-ZnO composites

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-TiO₂ or 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.