Preparation and Properties of Zinc Oxide Nano‐Hybridized Cellulose/Poly(Lactic Acid) Composite Films

ABSTRACT Excessive ultraviolet (UV) radiation causes human skin damage and lesions, and accelerates the aging of polymer materials. UV‐shielding materials made from traditional petroleum materials are not biodegradable, so the development of green UV‐shielding materials is urgent. In this study, poly(lactic acid) (PLA) was toughened by polyethylene glycol (PEG), and nano‐ZnO hybridized cellulose (MCC‐ZnO) was prepared by hydrothermal method. The UV‐shielding PLA/PEG/MCC‐ZnO (PLA/PMZ) composite films were prepared by solution casting method. The results showed that the toughness of PLA films was significantly improved by adding 5 wt% PEG, and the elongation at break increased from 5.2% to 242.52%, while the tensile strength was basically unchanged. The PLA/PMZ composite films with 3 wt% MCC‐ZnO have excellent UV shielding effect and satisfactory transparency, with a shielding rate of 92.2% at 320 nm UV and a visible light transmittance of 41.7%. Molecular dynamics simulations showed that the interaction between PEG and MCC‐ZnO promoted the formation of hydrogen bonds and improved the mechanical properties of PLA/PMZ. The PLA/PMZ composite films have excellent UV‐shielding effect, high transparency and flexibility, and are expected to be widely used in the fields of outdoor UV protection, food packaging materials, and agricultural films.