Preparation of Photodegradable Polypropylene/Clay Composites Based on Nanoscaled TiO2 Immobilized Organoclay

Abstract

Photodegradable polypropylene (PP) composites were prepared via melting blending using PP and titanium dioxide (TiO2) immobilized organically modified mont- morillonite (organoclay). TiO2 immobilized organoclay (TiO2-OMT) was synthesized by immobilizing anatase TiO2 nanoparticles on organically modified clay via sol- gel method. The structure and morphology of TiO2- OMT were characterized by XRD and scanning electron microscope (SEM), which showed that anatase TiO2 nanoparticles with the size range of 8-12 nm were uniformly immobilized on the surface of organoclay layers. Diffuse reflection UV-vis spectra revealed TiO2- OMT had similar absorbance characters to that of commercial photocatalyst, Degussa P25. The solid- phase photocatalytic degradation of PP/TiO2-OMT composites was investigated by FTIR, DSC, GPC and SEM. The results indicated that TiO2-OMT enhanced the photodegradation rate of PP under UV irradiation. This was due to that immobilization of TiO 2 nanopar- ticles on organoclay effectively avoided the formation of aggregation, and thereby increased the interface between PP and TiO2 nanoparticles. After 300 h irradiation, the average molecular weight was reduced by two orders of magnitude. This work presented a promising method for preparation of environment-friendly polymer nanocomposites. © 2008 Society of Plastics Engineers.