Development of Eco-Friendly and Durable Composites: Polypropylene Carbonate (PPC)–Polylactic Acid (PLA)/ZIF‑8 for Packaging Applications

The rising level of food waste has exacerbated climate change, and this issue is further intensified by the harmful environmental impact of the conventional plastics used in food packaging. In response, we have set out to address these concerns by developing nanocomposite films made of polypropylene carbonate (PPC) and polylactic acid (PLA) with different wt % (0.5, 1, 1.5, and 2 wt %) of the zeolite imidazole framework (ZIF-8), by using the solution casting method. ZIF-8 was prepared by using an eco-friendly solvothermal method. The structural insights of the prepared ZIF-8 and its nanocomposites were evaluated by using the FTIR, XRD, EDX, FE-SEM, mechanical and thermal analyses. The incorporation of ZIF-8 enhanced the tensile strength, with the nanocomposite containing 1.5 wt % ZIF-8 showing the highest tensile strength at 23 ± 0.9 MPa, significantly higher than the 7.17 ± 0.4 MPa of the neat PPC. Additionally, the thermal properties improved with the addition of ZIF-8, as the maximum degradation temperature for the 1.5 wt % ZIF-8 composite was found to be 276.70 °C, higher than that of the neat PPC. The nanocomposites demonstrated promising antimicrobial properties against Bacillus subtilis, by showing a maximum inhibition zone of radii of 20 mm for the nanocomposite with the highest wt % of ZIF-8. Moreover, the nanocomposites exhibited no toxicity towards the HEK293 cells and they demonstrated remarkable activity in preserving the shelf life of black grapes. Thus, the overall results suggest that the developed nanocomposite holds significant promise for applications in food packaging sectors.