Sustainable PVA-Chitosan Biocomposite Films: Effects of Chitosan Loading on Material Properties and Biodegradability

Abstract

Global reliance on non-biodegradable petroleum-based plastics is a significant environmental concern that necessitates the development of eco-friendly alternatives. Poly(vinyl) alcohol (PVA) shows high potential, but its application is limited because of its high moisture sensitivity and intermediate strength. In this study, the effect of crosslinking chitosan (CS) at 5-35% loading on different material properties and biodegradability of poly(vinyl) alcohol-chitosan (PVA-CS) biocomposite films was investigated. FTIR analysis confirmed the successful crosslinking between the two polymers. The integration of CS in the polymer matrix of PVA improved its UV-blocking properties by 25-55%. The degree of swelling and solubility is inversely related to %CS in PVA-CS films. Pure PVA and PVA-CS films showed higher tensile strengths but lower elongation at break compared to LDPE. Thermogravimetry showed 4-stage thermal degradation, with maximum degradation at 280-380°C for the PVA-based films. Significant improvement in the biodegradability of PVA films was observed with the incorporation of CS. Based on the tested %CS loading, a minimum of 15% CS is required to see significant improvement in the biodegradation rate, UV-blocking, and mechanical properties of the PVA-CS films. These findings have direct practical implications for sustainable engineering, showing the potential of PVA-CS biocomposites as a biodegradable alternative to traditional plastics.