Polylactic Acid/ Poly(Butylene Adipate-Co-Terephthalate) Packing Films Doped with Novel Antimicrobial Agent CuO@γ-CD-MOFs

Graphical The novel antibacterial agent CuO@γ-CD-MOFs was synthesized and then incorporated into the PLA/PBAT composite films for food packing materials. The films exhibited superior antibacterial activity and strong UV-blocking ability and water vapor barrier property. Besides, the complementary PLA and PBAT endowed the composite films with enhanced elongation at break compared with that of brittle PLA, and higher tensile strength than PBAT. The biosafe and reusable γ-CD-MOFs were employed as the copper oxide (CuO) carriers to counter the agglomeration of CuO nanoparticles (NPs); and such a novel antibacterial agent CuO@γ-CD-MOFs was synthesized by a facile and eco-friendly direct calcination approach, and then incorporated into the polylactic acid (PLA)/poly(butylene adipate-co-terephthalate) (PBAT) composite films for food packing materials. The effect of the CuO@γ-CD-MOFs nanoparticles on the antibacterial and physical properties was investigated, and the films with 5% CuO@γ-CD-MOFs NPs content displayed the optimal comprehensive performance. Specifically, the composite films PPM-5 exhibited superior antibacterial activity with the inhibition rates against Staphylococcus aureus and Escherichia coli exceeding 95%, which attributed to the uniformly dispersed CuO nanoparticles by metal organic frameworks (MOFs) carrier. Besides, the films provided strong UV-blocking ability and water vapor barrier property. Furthermore, the complementary PLA and PBAT endowed the composite films with enhanced elongation at break compared with that of brittle PLA, and higher tensile strength than PBAT. MTT assay confirmed the satisfactory biocompatibility. The composite films are expected to find great applications in the field of biodegradable food packing.