Preparation and study of the thermal, barrier and antibacterial properties of Polylactic acid-Fluorphlogopite-Silver nanoparticles nanocomposite films

Nowadays, there is an increasing need to develop new green biodegradable materials for active antimicrobial food packaging applications. In this work, polylactic acid-2 % Fluorphlogopite-1.5%silver nanoparticles (AgNPs) composites were prepared using melt extrusion. Films were characterized using Scanning Electron Microscopy, Transmission Electron Microscopy, X-Ray Diffraction, Differential Scanning Calorimetry, and Water Contact Angle measurements. Results showed a good dispersion of both fluorphlogopite and AgNPs in PLA which increased the surface roughness and hydrophobicity of PLA. Subsequently, the thermal, mechanical, and barrier properties of PLA nanocomposites were assessed. PLA-2%Fluorphlogopite-1.5%AgNPs showed a higher thermal stability than neat PLA while the mechanical properties remained unchanged. Furthermore, the excellent barrier properties of PLA were also unaffected by the introduction of fluorphlogopite and AgNPs. Finally, the antibacterial activity of the nanocomposites was assessed against three bacteria, S. aureus, E. faecalis, and E. coli and PLA-2%Fluorphlogopite-1.5%AgNPs inhibited almost completely the bacterial adhesion on the surface of the films.

Automated summary

In this study, polylactic acid-based composites were prepared and characterized, showing improved surface properties and antibacterial performance without compromising thermal stability and barrier properties. The addition of fluorphlogopite and silver nanoparticles enhanced the surface roughness and hydrophobicity of polylactic acid, resulting in inhibiting bacterial adhesion on the film surface.