Novel Photodegradable Low-Density Polyethylene−TiO₂ Nanocomposite Film

A new type of photodegradable low-density polyethylene (LDPE)-TiO2 nanocomposite film was prepared by a melt blending technique. The photocatalytic degradation of the LDPE-TiO2 nanocomposites was investigated. The as-prepared films were characterized by scanning electron microscopy (SEM), high-temperature gel permeation chromatography (HT-GPC), X-ray photoelectron spectroscopy (XPS), FT-IR spectroscopy, and the photoinduced weight loss. The results show that the LDPE-TiO2 nanocomposite films could be efficiently degraded under UV or sunlight illumination. The weight loss rate of the composite film reached 68.38%, the average molecular weight (Mw) of the composite film decreased 94.56%, and the number of average molecular weight (Mn) decreased 93.75% after UV-light irradiation for 400 h. FT-IR and XPS analysis indicated that the LDPE was oxidized during UV-light irradiation. The photocatalytic degradation mechanism of the films is briefly discussed.