Morphological, Mechanical, and Antimicrobial Properties of PBAT/Poly(methyl methacrylate-co-maleic anhydride)–SiO Composite Films for Food Packaging Applications

A poly(methyl methacrylate-co-maleic anhydride) P(MMA-co-MA) copolymer was synthesized via radical polymerization. The synthesized P(MMA-co-MA) copolymer was identified by H- and C-nuclear magnetic resonance spectroscopy (H-NMR), (C-NMR), Fourier-transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The poly(butylene adipate-co-terephthalate) (PBAT)/P(MMA-co-MA)–SiO composites were developed using a solution-casting method. The PBAT to P(MMA-co-MA) weight ratio was kept at 70:30, while the weight percentage of SiO nanoparticles (NPs) was varied from 0.0 to 5.0 wt.%. SiO was used for PBAT/P(MMA-co-MA) to solve the compatibility between PBAT and the P(MMA-co-MA) matrix. The PBAT/P(MMA-co-MA)–SiO composites were characterized by studied FTIR spectroscopy, XRD, SEM, and TEM. A comparison of the composite film PBAT/P(MMA-co-MA)–SiO (PBMS-3) with the virgin PBAT and P(MMA-co-MA) film revealed its good tensile strength (19.81 MPa). The WVTR and OTR for the PBAT/P(MMA-co-MA)–SiO composites were much smaller than for PBAT/P(MMA-co-MA). The PBAT/P(MMA-co-MA)–SiO WVTR and OTR values of the composites were 318.9 ± 2.0 (cc m per 24 h) and 26.3 ± 2.5 (g m per 24 h). The hydrophobicity of the PBAT/P(MMA-co-MA) blend and PBAT/P(MMA-co-MA)–SiO composites was strengthened by the introduction of SiO, as measured by the water contact angle. The PBAT/P(MMA-co-MA)–SiO composite films showed excellent antimicrobial activity against the food-pathogenic bacteria E. coli and S. aureus from the area of inhibition. Overall, the improved packaging characteristics, such as flexibility, tensile strength, low O and HO transmission rate, and good antimicrobial activities, give the PBAT/P(MMA-co-MA)–SiO composite film potential for use in food packaging applications.