Smart Film Based on Polylactic Acid, Modified with Polyaniline/ZnO/CuO: Investigation of Physicochemical Properties and Its Use of Intelligent Packaging of Orange Juice

Abstract

In this study, a biodegradable/conducting film based on polylactic acid (PLA) modified with polyaniline, zinc oxide, and copper oxide (PLA/PAn/CuO/ZnO) was prepared. The effect of polyaniline, zinc oxide, and copper oxide on the electrical, physicochemical, antioxidant, and antimicrobial properties of polylactic acid films by different techniques such as SEM, FTIR, and TGA were investigated. Electricity conductive films were used for intelligent packaging of orange juice. The chemical and microbial properties of orange juice and the electrical conductivity of packaging films during storage time (56 days) were investigated. The results showed that the effect of polyaniline, zinc oxide, and copper oxide greatly increased the antioxidant and antimicrobial properties of polylactic acid film. Polyaniline gave the film good electrical conductivity, but zinc oxide and copper oxide had no significant effect on it. The active film used to package the orange juice increased the chemical and microbial viability of the orange juice. The electrical resistance of the conductive films used for packaging increased over time and a significant mathematical relationship was established between storage time and changes in electrical resistance, which was used to estimate the shelf life and expiration date of orange juice. Examination of the performance of the films showed that these films with an accuracy of over 90% have the ability to estimate the storage time of orange juice. Electricity conductive/antimicrobial/antioxidant film based on polylactic acid as an active and intelligent film has the ability to increase the shelf life and detect spoilage of orange juice.