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 degrees C for PLA to 334 degrees C for PLA-g-Cur, highlighting enhanced thermal stability. Migration values for PLA-g-Cur films were >160x 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.