Synthesis and Characterization of PVA/Modified Starch/Acrylic Acid–Based Biocomposite Films

In this study, polymer films based on polyvinyl alcohol (PVA), modified starch, and acrylic acid (AA) were synthesized and characterized. For the first time, this work investigates the synergistic effect of incorporating AA into films based on PVA and preirradiated starch. Unlike conventional approaches that rely on simple blending of PVA and starch, the use of AA as a functional monomer enables the formation of a chemically cross‐linked structure, where the carboxyl groups of AA establish additional hydrogen and covalent bonds with the hydroxyl groups of PVA and starch, as confirmed by FTIR spectroscopy. Furthermore, this study employs starch that has been pretreated with electron beam irradiation, which enhances component compatibility and improves the mechanical and thermal properties of the films. A comprehensive analysis of the main physicochemical properties of the films showed that increasing the AA content led to a rise in gel fraction yield from 67.4% to 86.2%, indicating a denser cross‐linked polymer network. Thermogravimetric analysis demonstrated improved thermal stability with increasing AA content, with the decomposition temperature reaching up to 450°C and total mass loss reduced to 50%. Mechanical testing revealed a significant enhancement in strength and elasticity: The tensile strength increased from 300 to 500 kPa, and the Young’s modulus increased from 0.3897 to 0.5514 kPa. The obtained results suggest that PVA/starch/AA films hold great potential as a promising material for biodegradable packaging applications.