Sugarcane bagasse-derived xanthan gum improves polyvinyl alcohol films for food packaging

Abstract

Introduction: The increasing demand for environmentally responsible packaging materials has intensified the search for renewable alternatives to conventional fossil-based plastics. Among the available options, biodegradable polymers show great potential, although their mechanical performance and barrier properties still require improvement for broader industrial use. Materials and methods: In this study, films based on polyvinyl alcohol (PVA) and xanthan gum (XG), including two xanthan gum variants produced from sugarcane bagasse (XGL1 and XGL2), were prepared by the solvent-casting method and evaluated through mechanical, thermal, morphological, spectroscopic, and water vapor barrier analyses. Results: The incorporation of xanthan gum positively affected film performance, particularly for the PVA/XGL1 formulation. This film showed a 37.9% increase in tensile strength compared with pure PVA, an elongation at break of 270.97%, lower water vapor permeability (0.243 g·mm/m2·h·kPa), and a higher contact angle (80.81°), indicating reduced sensitivity to moisture. Fourier transform infrared spectroscopy (FTIR) results suggested strong intermolecular interactions between PVA and xanthan gum, while Field emission gun scanning electron microscopy (FEG-SEM) analysis revealed homogeneous and compact structures. Conclusions: Although the films remained moderately water-soluble and thermal degradation began near 200 °C, the overall performance obtained demonstrates the potential of the PVA/XGL1 blend for food packaging applications. In addition to improving material properties, the use of xanthan gum produced from sugarcane bagasse provides a productive route for valorizing agro-industrial residues, contributing to the development of sustainable packaging materials with reduced environmental impact.