Development of thermal insulation packaging film based on poly(vinyl alcohol) incorporated with silica aerogel for food packaging application

To develop thermal insulation packaging film, poly(vinyl alcohol) (PVA) films incorporated with silica aerogel (SA) were prepared. The effects of SA content on structural, physicochemical properties, thermal conductivity of films and evaluation of the films' thermal insulation property through chocolate packaging were investigated. The SA was dispersed uniformly in the films as SA increased from 0% to 3%. Some aggregations were observed in films containing 5% and 7% SA. And some small pores were observed in the films and their quantity increased with increasing SA. This also contributed to the films’ thermal insulation because of low thermal conductivity of air. The water vapor barrier property and thermal stability of films were improved for SA incorporation and the oxygen barrier property of films containing 3% SA was best among all developed films. All films added with SA exhibited much lower thermal conductivity than the pure PVA film and it decreased significantly with increasing SA. The result of its application for chocolate packaging showed that the films incorporated with SA can prevent chocolate from softening better and the protective effect increased with increasing SA. These films will be prospective to be used in multilayer packaging systems for temperature-sensitive foodstuffs packaging applications.