Reactive Extrusion of Poly(lactic acid)-graft-Curcumin Antioxidant and Intelligent Packaging

Antioxidant and intelligent poly(lactic acid)- n (PLA- g -Cur) was synthesized by peroxide-initiated reactive extrusion as a low-cost, sustainable packaging material to reduce the economic and environmental burden of food and plastic waste. The superior mechanical properties of PLA- g -Cur compared to radically processed PLA without curcumin suggested antioxidant stabilization of PLA- g -Cur that inhibited the degradation of the polymer backbone. These results were supported by an increased onset decomposition temperature ( T 95 ) from 315 °C for PLA to 334 °C for PLA- g -Cur, highlighting enhanced thermal stability. Migration values for PLA- g -Cur films were >160× below the EU migratory limit for food contact polymers (0.1 mg/cm 2 ), supporting the use of PLA- g -Cur packaging in a wide range of food applications. Modified PLA blocked >93% of UV light while maintaining 89% visible light transmittance, demonstrating the potential to inhibit photooxidation while maintaining material transparency. Significant radical scavenging and spoilage indicating performance of PLA- g -Cur further supported this method as an industrially scalable technology to reduce food and plastic waste.