Sustainable Millet Husk–Based Green Xerogel–Coated Polymer Composite for Eco-Friendly Packaging Solutions

Paper and corrugated boards are eco-friendly alternatives for packaging, but their dependence on wood drives deforestation, while polyethylene coatings used for water resistance compromise biodegradability. To address these rigorous challenges, we developed a high-performance biodegradable composite sheet by utilizing plant-based biomass generated from banana pseudostems and millet husks obtained from foxtail millet. Biomass was chemically modified into microfibers, which were then blended with GG and CH to form a composite sheet via vacuum filtration and crosslinking. The obtained sheet, being hydrophilic, was further coated with a biopolymer-based xerogel coating to enhance hydrophobicity, achieving a contact angle of 94°, confirming its water-repellent nature. Morphological SEM analysis confirmed that the biomass was converted into a microfiber structure. The composite sheet exhibited 82.38% higher tensile strength, 414.96% greater tear strength, and 27.27% higher elongation than a commercial paperboard. The synthesized composite film exhibited a 100% UV barrier property. Biodegradation and LCA studies of the composite sheet explored the eco-friendly nature of the fabricated material. Thus, the xerogel-coated composite sheet exhibited excellent mechanical strength and moisture resistance, making it an eco-friendly solution for packaging and paving the way toward a greener, more sustainable future.