High photocatalytic degradation activity of polyethylene containing polyacrylamide grafted TiO_2

摘要

A novel photocatalytic polyacrylamide grafted TiC>2 (PAM-g-TiO_2) nanocomposite was prepared and embedded into a low density polyethylene (LDPE) plastic. Photocatalytic degradation of the LDPE/PAM-g-TiO_2 composite film was carried out under ambient conditions under ultraviolet light irradiation. The properties of composite film were compared with those of the pure LDPE film by measuring the changes in weight loss, carbonyl index, molecular weight, tensile strength and elongation at break. PAM-g-TiCO_2 embedded LDPE showed highly enhanced photocatalytic degradation. Irradiating the LDPE/PAM-g-TiO_2 composite film for 520 h under UV light reduced its weight by 39.85％ and average molecular weight (M_w) by 94.60％, while that of pure LDPE film was only 1.03％ and 69.59％, respectively. The addition of PAM-g-TiO_2 brought about the good dispersion of TiO_2 in LDPE matrix and improved the hydrophilicity of composite film, which were able to facilitate the degradation of LDPE. The photocatalytic degradation mechanism of the films is briefly discussed.