Poly (Lactic Acid)/Starch Biodegradable Blend With Antioxidant Activity: A Sustainable Alternative for Single‐Use Active Plastic Packaging

ABSTRACT A novel bio‐based and biodegradable plastic based on poly(lactic acid) (PLA) and corn starch (CS) was developed as a single‐use rigid packaging material. Chitosan (Q) and eucalyptus essential oil (EEO) were incorporated as antimicrobial and antioxidant agents. The effects of these additives were evaluated using a three‐factor, two‐level factorial design, assessing the melt flow index (MFI) and tensile properties. The optimized formulation, containing 5 wt% of EEO and 3 wt% of Q, increased the thermal stability of CS due to the PLA matrix with two degradation steps: 145°C and 318°C. It also demonstrated low water interaction, with a solubility of approximately 0.6% and a moisture content of 5%, attributed to the absence of plasticizers. Additionally, the material achieved nearly 70% antioxidant activity through the synergistic effect of EEO and Q. Successful thermoforming trials confirmed the processability of the optimized formulation. Comparative analysis with polypropylene revealed that the bio‐based material exhibited higher tensile strength while offering the critical advantage of biodegradability. These findings highlight the potential of this active, thermoformable bio‐based material as a sustainable alternative to conventional non‐biodegradable plastics.