Ethylene vinyl acetate/low-density polyethylene/oyster shell powder composite films: Preparation, characterization, and antimicrobial properties for biomedical applications

Background: To maintain the biocompatibility, the addition of natural antimicrobial compounds to the conventional polymeric materials is being heavily investigated to serve antimicrobial single use products. Methods: This study focus on the fabrication of ethylene-vinyl acetate/low-density polyethylene/calcined oyster shell powder (OSP) composite films via blown film extrusion method and study of its physicochemical properties including antimicrobial properties for biomedical applications. To improve the miscibility, OSP dispersion, and mechanical properties of the composite films, polyethylene graft maleic anhydride (PEgMA) was further introduced as a compatibilizer. The prepared composites films were characterized by Fourier-transform infrared spectroscopy in attenuated total reflection mode (ATR-FTIR), solid-state ¹³C nuclear magnetic resonance (NMR), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), thermal properties (TGA and DSC), field emission scanning electron microscope (FESEM), energy-dispersive X-ray spectroscopy (EDS), transmission electron microscope (TEM), mechanical properties, and water resistance. Moreover, antimicrobial properties were evaluated for the selected samples. Significant findings: OSP imparts the composite films with antimicrobial activity against Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria, in addition to remarkably enhancing the thermal stability of the resulting material. From the FESEM analysis, the morphologies of the composite films showed homogenous in the case of PEgMA (1 wt%) and OSP (3 wt%) composite film due to the low interfacial tension and high chemical tendencies in the composite matrix.