Starch Maleate/Epoxidized Soybean Oil/Polylactic Acid Films with Improved Ductility and Biodegradation Potential for Packaging Fatty Foods

The commercial marketability of polylactic acid (PLA) food packaging films is limited by their poor ductility and biodegradation ability. To address these challenges, a high-DS amylose-rich corn starch maleate (SM)/epoxidized soybean oil (ESO)/PLA composite film was developed. The film demonstrated significant ductility improvement (elongation at break increased from ≈3.63 to 36.75% while the tensile toughness improved 15-fold compared to the neat PLA film) because of improved interfacial interactions and mobility of ESO-plasticized PLA chains. Furthermore, due to absence of voids, the SM/ESO/PLA film also outperformed the ESO/PLA film in terms of oxygen (23,140 cm3 μm m–2 day–1 Pa–1) and water vapor (0.03 × 10–5 g m–1 day–1 Pa–1) barrier performances. These characteristics, together with findings that the SM/ESO/PLA film could rapidly breakdown in saline water (2.92 wt % per day) and compost (the C/N ratio increased from 20.4 to 22.69), as well as absence of ESO migration in fatty food simulants, make the SM/ESO/PLA film a promising material for food packaging.