Fabrication and Performance of PBAT Composite Films Reinforced with High-Molecular-Weight Lignin Nanoparticles for Sustainable Packaging
Zhongshan Wang, Changgeng Li, Xiaodi Liu, Wenchao Jia, Lingzhi Huang, Lu Wu, Pedram Fatehi, Haiqiang Shi
Abstract
This study focuses on the incorporation of lignin nanoparticles (LNPs), prepared via antisolvent precipitation from fractionated lignin, into poly(butylene adipate- co -terephthalate) (PBAT) matrices and evaluates the effects of LNP particle size on the properties of PBAT composite films. The results demonstrate that, compared to the original lignin, LNPs acted as functional fillers, exhibiting excellent dispersion within the PBAT matrix. Strong hydrogen bonding interactions between LNPs and PBAT significantly improved the mechanical properties of the composite films, with an 8 wt % addition of LNPs leading to a 62.1% increase in tensile strength. High-molecular-weight LNPs (25 ∼ 116 nm), characterized by smaller particle sizes, achieved superior dispersion and compatibility within the PBAT matrix compared to low-molecular-weight LNPs. This improved dispersion contributed to enhanced tensile strength, UV-shielding capability, and barrier properties of the films. Additionally, PBAT films containing high-molecular-weight LNPs with a lower hydrophilic group content displayed higher antioxidant and antimicrobial activities. These findings highlight the potential of high-molecular-weight LNPs-reinforced PBAT composite films as sustainable food packaging materials. They also provide innovative strategies for the high-value utilization of lignin and the development of degradable high-performance packaging solutions.