Biodegradable Poly(Vinyl Alcohol)/Starch Films Crosslinked With Itaconic Acid for Sustainable Packaging Applications

Biodegradable polymer films based on poly(vinyl alcohol) (PVA), starch (S), and itaconic acid (IA) were fabricated via solution casting to assess their potential for sustainable packaging applications. FTIR confirmed esterification between the hydroxyl and carboxyl groups, indicating successful crosslinking. Mechanical tests revealed that the balanced PVA/S/IA (33.3/33.3/33.3 wt%) film presented the highest tensile strength (10.5 ± 0.8 MPa) and elongation at break (38.9% ± 2.4%), whereas IA-rich films demonstrated increased viscosity (up to 3250 ± 110 cP) and improved thermal stability with decomposition temperatures ∼15°C-20°C higher than those of starch-rich films. Conversely, starch-rich films displayed faster biodegradation, with up to 67% mass loss in soil after 30 days, whereas the mass loss rates were 42% for balanced films and 28% for IA-rich formulations. All the films fragmented in water within 24 h without complete dissolution due to the presence of a crosslinked three-dimensional network. These findings demonstrate that formulation ratios markedly influence mechanical performance, solubility behavior, and degradation kinetics. Overall, the tunability of PVA/S/IA films highlights their potential as biodegradable alternatives to petroleum-based single-use packaging materials.