Lignin nanoparticle reinforced polyvinyl alcohol, rice starch water and sodium alginate blend film for food packaging applications

The development of biodegradable packaging materials is crucial for minimizing the environmental impact of traditional synthetic packaging. In this study, polyvinyl alcohol (PVA), rice starch water (RSW), and sodium alginate (SA) blended biocomposite films, reinforced with sugarcane bagasse-derived lignin nanoparticles (LNPs), were developed adopting the solvent casting method. FESEM analysis showed uniform dispersion of spherical LNPs (60 nm in diameter) throughout the film. FTIR also confirmed strong –OH interactions between LNPs and polymers. The quaternary film (PSAL), containing RSW, SA, and LNPs in the PVA matrix, showed improved water-holding capacity (19.8%), film solubility (14.5%), moisture content (2.12%), tensile strength (18.7±1.73 MPa), elongation at break (118.1±11.6%), and Young's modulus (0.288±0.036 GPa) compared with the pure PVA film (P film). The PSAL film exhibited good antibacterial activity against both gram-positive (Bacillus cereus) and gram-negative (Escherichia coli) bacteria, UV-light barrier properties, and an enhanced biodegradation rate. These findings suggest the potential of the developed PSAL film for food packaging applications.