To study the relationship between performance changes and nanoparticles migration of the composite film at different migration stages, the poly (lactic acid) (PLA)/nano-TiO2 composite film treated by high pressure was immersed in 50% (v/v) ethanol solution for 45 days at 40 °C, and the film characteristics and migration behavior were analyzed. The results showed that the migration of the composite film with the highest loading of nano-TiO2 (20 wt. %) in alcoholic food simulated solution was far less than 10 mg/kg during the 45-day migration process. Although with the increase of migration time, the micro-morphology of composite film became rougher, the crystallinity decreased and the gas permeability increased, but the internal crystal structure of the composite film remained basically unchanged. The PLA/nano-TiO2 composite films treated by high pressure treatment were relatively stable, and had good performance and migration behavior in alcoholic food simulated solution, the nanocomposite film after high pressure treatment could be used to reduce nano-TiO2 particle migration and subsequently reduce human exposure as the packaging film for the packaging of alcoholic food, which provide a theoretical basis for the applications of high pressure treatment of PLA/nano-TiO2 composite films in food packaging material and broaden its application prospects.
Keywords: high pressure treatment; migration; nano-TiO2; poly (lactic acid).