Abstract:

 Chitosan-Brazil sweet orange oil composite films were prepared with chitosan (CS) and Brazil sweet orange oil
(BSOO) by a casting-evaporation-alkali leaching method. Microstructural properties of the films were characterized by
Fourier transform infrared reflectance spectroscopy (FTIR) and X-ray diffraction (XRD). The effect of BSOO content on
film thickness, tensile strength (TS), elongation at break (E), contact angle (CA), water vapor permeability (WVA), total
soluble matter content (TSMC) and swelling index (SI) were investigated. The results indicated that the locations of partial
functional groups of CS matrix were occupied by BSOO. The regularity of CS matrix was decreased by the incorporation of
BSOO, resulting in the increasing content of chitosan-acetate in films. When BSOO content was 2%, E reached the minimum
value, 10.07%. CA and TSMC of films increased with increasing BSOO content, and maximum CA and TSMC were
81.15 ° and 4.24%, respectively. When BSOO content was 6%, WVP attained the maximum level of
313.32 mg·mm/(kPa·h·m2). Minimum SI (0.49) was achieved for 8% CS-BSOO film. The incorporated BSOO improved the
physical and mechanical properties of chitosan-based composite films prepared by casting-evaporation-alkali leaching
method. The research results could provide a technical basis for the production and application of CS-BSOO composite films.

Key words: chitosan, films, essential oils, physical properties, mechanical properties