Antimicrobial film based on polylactic acid and carbon nanotube for controlled cinnamaldehyde release

A controlled-release antibacterial active food packaging film was prepared from polylactic acid (PLA), poly (ε-caprolactone) (PCL), carbon nanotubes (CNTs), and cinnamaldehyde (CIN) by solvent evaporation method. The properties and antibacterial activities of CIN loaded PLA/CNTs/CIN film was characterized. Furthermore, the release behavior of CIN from PLA-based antibacterial film was quantified. The introduction of CNT and CIN would not significantly affect the barrier properties of PLA-based film, but would significantly enhance the UV resistance of the film. The co-action of CNTs and CIN led to the decrease of the glass transition temperature of the film and enhanced the elongation at break of the film. The PLA/CNTs/CIN film could continuously release CIN for 21 days in ambient storage, and antibacterial effect of the film on Staphylococcus aureus and Escherichia coli could be maintained for 21 days, during which the antibacterial effect gradually reduced and maintained for 7 days longer than the film without CNTs. According to the research results, The PLA/CNTs/CIN composites have great application potential in antibacterial active food packaging film.