Abstract: Due to the hydrophilic property, the application of poly vinyl alcohol (PVA) in food package is greatly limited. In this paper, the effect of PVA-based composite film modified by adding nano-SiO2 on packaging efficacy was evaluated by measuring vapor transmission rate, water-absorbing rate, transmittance, gas permeability and antibacterial capability. The results showed that vapor transmission rate (18.78 g/(m2 ·d)), water-absorbing rate (1.40%) of modified composite film decreased by 35.34%; O2 and CO2 penetration (0.055 g/(m2 ·d) and 0.174 g/(m2 ·d)) of modified composite film decreased by 17.91% and 18.31%, respectively, compared with those of PVA-based composite film without modification. Moreover, the antibacterial capability of PVA-based composite film was also improved after the modification with nano-SiO2. Therefore, modification with nano-SiO2 can significantly enhance the barrier performance, especially vapor barrier performance of PVA-based composite film, and consequently improve the application efficiency in food package.

Key words: poly vinyl alcohol (PVA), nano-SiO2, composite film modification, vapor transmission rate of composite film, gas permeability