Bioactive Polypropylene/Poly(butylene adipate- co -terephthalate) Composite Films Loaded with Essential Oil for Active Food Packaging

The demand for advanced food packaging materials that enhance product quality and reduce food waste is rapidly increasing. To address this need, polypropylene (PP)-based composite films were prepared by incorporating poly(butylene adipate- co -terephthalate) (PBAT) and citronella essential oil (CEO) through melt mixing and cast extrusion, yielding functional packaging with improved performance and bioactivity. PBAT was incorporated into PP at various ratios (5–20 wt %) using melt mixing and cast extrusion with the 90/10 (PP/PBAT) composition exhibiting optimal processability, structural uniformity, and mechanical performance. Rheological analysis revealed shear-thinning behavior and an enhanced storage modulus, indicating improved melt elasticity and structural homogeneity. Mechanical testing showed a 17% increase in elongation at break and a 6.57% rise in elastic modulus compared to neat PP, attributed to partial interfacial compatibility and stress transfer across polymer phases. FT-IR and XRD results indicated weak interfacial interactions between PP and PBAT along with enhanced crystallinity, contributing to reduced water vapor permeability and melt flow index. CEO was successfully incorporated into the optimized blend, imparting strong antibacterial activity against Escherichia coli and Staphylococcus aureus (inhibition zones >10 mm). In vitro cytotoxicity assays using L929 fibroblast and HEK293 epithelial cells confirmed (>90%) the nontoxic nature of the CEO-infused films. The incorporation of biodegradable PBAT and biobased CEO not only extended the shelf life of cherry tomatoes but also supported Sustainable Development Goal-12 (Responsible Consumption and Production) by reducing fossil dependence, minimizing food loss, and advancing responsible packaging practices.