Preparation of photodegradable polypropylene/clay composites based on nanoscaled TiO₂ immobilized organoclay

Photodegradable polypropylene (PP) composites were prepared via melting blending using PP and titanium dioxide (TiO 2 ) immobilized organically modified montmorillonite (organoclay). TiO 2 immobilized organoclay (TiO 2 ‐OMT) was synthesized by immobilizing anatase TiO 2 nanoparticles on organically modified clay via sol–gel method. The structure and morphology of TiO 2 ‐OMT were characterized by XRD and scanning electron microscope (SEM), which showed that anatase TiO 2 nanoparticles with the size range of 8–12 nm were uniformly immobilized on the surface of organoclay layers. Diffuse reflection UV–vis spectra revealed TiO 2 ‐OMT had similar absorbance characters to that of commercial photocatalyst, Degussa P25. The solid‐phase photocatalytic degradation of PP/TiO 2 ‐OMT composites was investigated by FTIR, DSC, GPC and SEM. The results indicated that TiO 2 ‐OMT enhanced the photodegradation rate of PP under UV irradiation. This was due to that immobilization of TiO 2 nanoparticles on organoclay effectively avoided the formation of aggregation, and thereby increased the interface between PP and TiO 2 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. POLYM. COMPOS., 2009.