Improvement of PLA-PVA/chitosan nanocomposite laminate film for packaging via crosslinking with electron beam irradiation: Mechanical, thermal and antimicrobial analysis

This research investigated and developed a laminate packaging film of poly(lactic acid) (PLA) and poly(vinyl alcohol) (PVA) containing modified chitosan nanoparticles (MCSNPs) treated with 3-(trimethoxysilyl)propyl methacrylate silane (TMSPM) which functioned both as a reinforcement and as an antimicrobial filler. Electron beam irradiation caused crosslink between the PVA and MCSNP molecules via the free radical of carbonyl in the methacrylate group of TMSPM-grafted chitosan nanoparticles and the free radical of hydroxyl group in poly(vinyl alcohol). This improved the PVA hydrophobicity. In addition, the laminate with PVA-g-MCSNPs film irradiated with a 30 kGy electron beam showed the best performance properties due to improved interfacial adhesion between PLA and PVA-g-MCSNPs. As a consequence, the mechanical and thermal properties improved. The 30 kGy irradiated film also had better antibacterial activity against both Escherichia coli and Staphylococcus aureus.