In Situ Reactive Extrusion of LDPE Films with Methacrylated Pyrogallol for Antimicrobial and Antioxidant Active Packaging

Abstract

Reactive extrusion is a scalable technology for active packaging that promotes food quality and safety. This study investigated the grafting of a methacrylate pyrogallol (PGMC) active agent onto low-density polyethylene (LDPE) through an in situ reactive extrusion process with varying concentrations of PGMC (1, 3, and 5 wt.%). The addition of 5% PGMC increased the tensile strength of pure LDPE from 17.94 MPa to 22.04 MPa. The thermal stability of the samples remained unaffected after PGMC addition, and the grafting process did not interfere with the barrier properties of the LDPE films. Furthermore, 5% PGMC exhibited significant antimicrobial properties, showing 100% and 99.11% reductions in the microbial activity of Escherichia coli (Gram-negative) and Staphylococcus aureus (Gram-positive), respectively. Moreover, the LDPE film with 5% PGMC demonstrated the highest DPPH scavenging effect, reaching up to 85.71%. Therefore, LDPE-g-PGMC films (5%), with antimicrobial and antioxidant properties, have potential applications in non-migratory active packaging.