Extracted supercritical CO2 cinnamon oil functional properties enhancement in cellulose nanofibre reinforced Euchema cottoni biopolymer films

Abstract

The improved properties of Euchema cottoni biopolymer films are significant determinants as a functional material. In this study, cinnamon oil extract reinforced cellulose nanofibre biopolymer films were fabricated. The CNF isolated via supercritical CO2 was obtained from bamboo precursor to enhance the properties of the films at different concentrations of cinnamon essential oil obtained from cinnamon bark which were incorporated in the matrix networks. The physico-chemical, thermal and antimicrobial properties of the isolated CNF reinforced E. cottoni biopolymer films was obtained using scanning electron microscopy (SEM), Fourier transmission irradiation (FT-IR), Atomic forced microscopy (AFM), water contact angle measurement (WCA), thermogravimetric analysis (TGA) and antimicrobial properties. The characterization study was carried out for improved mechanical, thermal, morphological, wettability and antimicrobial properties. The result revealed that the morphology, mechanical, and wettability properties of the biopolymer films were significantly enhanced with the incorporation of 1, 2, 3 and 4% (w/w) of cinnamon essential oil in the matrix structure containing CNF. The hydrophobic property of the film was enhanced with the incorporation of cinnamon oil extract indicated decrease in surface roughness of the films which were exhibited by increased water contact angle compared to the neat film. The homogenous dispersion of CNF resulted to decreased surface roughness relative to the neat film by 314.96 to 48.30 Rq respectively. The hydrophobicity of the films increased as concentration of cinnamon oil in the matrix component was increased as the surface roughness decreased. Increased hydrophobic property of the film was noticed after the incorporation of 3% concentration of cinnamon oil with equivalent contact angle of 92.36○. The tensile properties of the biopolymer film was significantly improved as SW/CNF/C3 cinnamon oil was incorporated in the matrix. The optimum tensile strength was exhibited by the film by the addition of 3% concentration of essential oil, 75.2% cinnamaldehyde was contained in the oil extract. The E. cottoni derived biopolymer film demonstrated satisfactory mechanical and thermal stability including improved surface hydrophobicity. Furthermore, the biofilms exhibited good inhibition activity against Staphylococcus aureus and Escherichia coli bacteria with the incorporation of the cinnamon oil extract with inhibition zone diameter at 26.94 ± 9.4 and 30.28 ± 0.46 respectively indicating effective antimicrobial activities of the biofilm. The functional properties of the fabricated biopolymer film was enhanced with the addition of cinnamon oil.

Keywords

• Supercritical extraction
• Reinforcement
• Cellulose nanofibre
• Cinnamon oil
• Biopolymer film