Abstract:

To improve the antibacterial effect of chitosan film, cinnamaldehyde was added into it. As a result, we obtained
an antibacterial composite film. The effects of cinnamaldehyde concentrations on the mechanical properties, physical
properties, water vapor permeability, functional group structure, degree of crystallinity, microstructure, and antimicrobial
properties of the composite film were studied. The results indicated that the color aberration, water vapor permeability
and elongation at break of the film were decreased whereas the thickness of the film was increased significantly with
increasing concentration of cinnamaldehyde (P < 0.05). When the cinnamaldehyde concentration was 2%, the lowest tensile
strength (15.77 ± 1.13) MPa was obtained. Fourier transform infrared spectroscopic analysis revealed a better compatibility
with chitosan and cinnamaldehyde. Increasing the concentration of cinnamaldehyde led to an increases in crystallinity,
crack and roughness of the composite film surface. The antibacterial efficiency of the film was increased with increasing
cinnamaldehyde concentration. The results obtained in this study can provide a new reference for the application of
chitosancinnamaldehyde antimicrobial biodegradable composite films.

Key words: chitosan film, cinnamaldehyde, structure characterization, antimicrobial activity