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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. [ABSTRACT FROM AUTHOR]

Effects of high pressure treatment (0, 200 and 400 MPa) on water vapour barrier, microstructure, thermal, and mechanical properties of poly (lactic acid) (PLA)/Ag nanocomposite films were investigated. The migration behavior of nano-Ag from the nanocomposite films in the presence of 50% (v/v) ethanol as a food simulant was also studied. The water vapour barrier properties increased as pressure was applied to film-forming solutions. High pressure treatment enhanced the mutual effect between PLA and nanoparticles, leading to a more compact network structure in PLA/Ag nanocomposite films. Furthermore, PLA/Ag nanocomposite films treated by high pressure were significantly affected by microstructure, thermal, and mechanical properties when, compared with untreated samples. High pressure treatment at 200 to 400 MPa significantly (p < 0.05) reduced the migration of nano-Ag from the films. Overall, high pressure treatment on film-forming solutions showed potential in improving the functional properties of nanocomposite films, especially in relation to water vapour barrier properties. [ABSTRACT FROM AUTHOR]

The poly(lactic acid) (PLA)/nano-TiO 2 composite films with different nano-TiO 2 loading (0 wt%, 1 wt%, 5 wt%, 10 wt%, 15 wt%, and 20 wt%) were prepared and contacted with 50% (v/v) ethanol solution as food simulant to study the behavior of nano-TiO 2 migration. The structural changes and intermolecular interactions were determined by scanning electron microscopy (SEM), X-ray diffraction (XRD), and differential scanning calorimetry (DSC). The migration amount increased with the increase of initial nano-TiO 2 content. SEM images demonstrated that the microstructure of PLA nanocomposite films became rougher as exposure to ethanol solution in a few days. XRD spectra indicated that a decrease in the intensity of specific diffraction peak occurred as the decrease in nano-TiO 2 content of PLA nanocomposite films during exposure to ethanol simulant. DSC analysis confirmed that the higher crystallinity percentage obtained during the different degradation times. The reasonable food packaging application of the nano-TiO 2 composite films with restrained nano-TiO 2 migration could be accomplished by controlling the nano-TiO 2 loading. • PLA/nano-TiO 2 films were contacted with 50% (v/v) ethanol solution as food simulant. • The migration amount increased with the increase of initial nano-TiO 2 content. • PLA nanocomposite films became rougher as exposure to ethanol solution in a few days. • A decrease in the peak intensity occurred during exposure to ethanol simulant. • Restrained nano-TiO 2 migration could be accomplished by controlling nano-TiO 2 loading. [ABSTRACT FROM AUTHOR]

The effects of nano-Ag content, high pressure treatment, and migration time on nano-Ag migration and properties of polylactide (PLA)/nano-Ag composite films were investigated. The PLA films incorporated with 1 wt%, 5 wt%, 10 wt%, 15 wt%, and 20 wt% nano-Ag were treated by 100, 200, 300, and 400 MPa high pressure for 10, 20, and 30 min, respectively, and then soaked in isooctane food simulant at 40 °C for 49 days. The migration of nano-Ag in the PLA nanocomposite films increased by the addition of nano-Ag, the pressure of high pressure treatment, and migration time. Thermal and mechanical properties showed that high pressure and migration time would make the films rougher and increase the crystallization temperature of the PLA nanocomposite films. Moreover, the addition of nano-Ag could improve the barrier properties of the PLA nanocomposite films. However, the longer the migration time, the worse the barrier property. The results indicated that the migration amount of nano-Ag and performance of the PLA/nano-Ag composite films were greatly affected by the migration time. • This paper applied high pressure technology to the preparation of composite film materials. • The addition of nano-Ag could increase the crystallinity of the composite films. • The migration of the nano-Ag/PLA composite films in the oily food simulating liquid was safe. • As the migration time increased, the barrier and mechanical properties of the composite films deteriorated. • The results indicated that the migration of nano-Ag in the composite films increased as the initial addition quantity of nano-Ag. [ABSTRACT FROM AUTHOR]