Biodegradable <scp>PVA</scp> / <scp>CMC</scp> Composite Films Cross‐Linked With Lactic and Oxalic Acids: Characterization and Application in Sustainable Food Packaging

Abstract

ABSTRACT Growing environmental concerns about single‐use plastic packaging have intensified the search for sustainable, biodegradable materials. This work presents the design of environmentally friendly polymer films based on polyvinyl alcohol (PVA) and carboxymethyl cellulose (CMC), incorporating lactic acid (LA) and oxalic acid (OA) as cross‐linking agents to enhance their overall performance. The prepared films were characterized using Fourier‐transform infrared spectroscopy (FTIR), x‐ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), tensile testing, and soil burial degradation studies. Films cross‐linked with OA displayed the highest biodegradation rate (90%) and a contact angle of 79°, while LA‐cross‐linked films achieved 80% biodegradability with improved hydrophilicity. Both acids significantly enhanced tensile strength, thermal resistance, and barrier properties, making them suitable for food packaging. Trials with fruits and vegetables demonstrated their ability to maintain freshness and minimize weight loss. Overall, PVA/CMC composites represent a renewable, eco‐conscious alternative to plastic packaging, and further investigation is encouraged to support industrial scalability, economic feasibility, and long‐term stability.