Preparation and characterization of nanoclays-incorporated polyethylene/thermoplastic starch composite films with antimicrobial activity

Polyethylene (PE) composite films incorporated with nanoclays, organically modified montmorillonite (OMMT) and silver-loaded montmorillonite (Ag-MMT), and thermoplastic starch (TPS) were prepared using an extrusion blowing method, and their properties such as optical, tensile, thermal, water vapor barrier, oxygen gas barrier, and antimicrobial activity were tested. The composite films were flexible, homogeneous, smooth but yellowish, and less transparent than the neat PE film. Increasing the composite additive content (OMMT + Ag-MMT with TPS) did not improve the composite film's optical, tensile, thermal, and barrier properties. However, no significant differences were observed between the control film and the composite film in water contact angle, XRD pattern, and microstructure. The composite films showed strong antibacterial activity against Listeria monocytogenes and E. coli O157:H7. The PE/clay/TPS composite films with 2.5 wt% of the compounded additives had desirable physical properties and efficient antimicrobial activity for active food packaging applications.