Versatile strategy for fabrication of polypropylene nanocomposites with inorganic network structures based on catalyzed in-situ sol-gel reaction during melt mixing

摘要

A versatile strategy based on a catalyzed in-situ sol-gel reaction in melt mixing is presented for the fabrication of polypropylene (PP) nanocomposites that equip inorganic network structures. PP nanocomposites with TiO_2 network structures were obtained by melt mixing PP powder which was preliminarily impregnated with titanium alkoxide and a catalytic component. The addition of catalytic components, especially hindered amine stabilizer, was found to be effective not only for the acceleration of the in-situ sol-gel reaction but also for improved dispersion of formed inorganic nanoparticles. The obtained PP/TiO_2 nanocomposites exhibited the disappearance of the terminal flow at ca. 3 wt% of the TiO_2 content, indicative of the network formation. Moreover, the PP/TiO_2 nanocomposite films exhibited distinct optical properties: Not only high transparency for visible lights due to the excellent dispersion of the made nanoparticles but also absorption of UV lights, where absorption edges are tunable through a quantum effect for nanosized particles.