Enhanced physical properties and water resistance of films using modified starch blend with poly(vinyl alcohol)

Abstract

Research into sustainable biopolymer films is increasingly focused on finding viable alternatives to petroleum-based plastics. This study aims to address these challenges by examining the performance of a series of films prepared using polyvinyl alcohol (PVA) with varying degrees of saponification (DS) and polymerization (DP), combined with two modified starch: hydroxypropyl starch (HPS) and sodium octenylsuccinate starch (OctS). The findings demonstrate that increased PVA saponification and polymerization levels greatly improved the physical properties of the PVA/Starch blends because of the interactions and intermolecular entanglement between the PVA and starch chains. By altering the PVA and starch formulations, the blend films' tensile qualities and water resistance were greatly improved; at a 7:3 ratio, the highest tensile strength (TS) is ∼17.4 MPa, and elongation at break (EAB) is ∼476.8 %. The tensile properties and water resistance of the blend films were significantly enhanced by varying the PVA and starch formulations, achieving the highest tensile strength (17.4 MPa) and elongation at break (476.8 %) at a 7:3 ratio. Moreover, the PVA/OctS-7 blend exhibited superior water durability, and high transparency, with the lowest swelling (∼108.6 %) and certain wet strength, as well as varied solubility behaviors in different pH solutions, rendering it appropriate for use in packaging applications. As a result, PVA/Starch blend films' functional qualities can be significantly improved, making them appear as viable substitutes for petrochemical plastic packaging.