Characterization of cyclic olefin copolymer‐coated chitosan bilayer films containing nanocellulose and grape seed extract

Abstract

This study evaluated the effect of applying cyclic olefin copolymer (COC) on the physico‐mechanical properties of chitosan (CH) film. Grape seed extract (GSE) (15%, w/w) was added to the CH film solutions to develop an active bilayer, while also adding nanocellulose (NC) (0% to 2%, w/w) to obtain better mechanical properties for CH. Characterization was carried out by contact angle measurements, scanning electron microscopy (SEM), optical analysis, and tensile and water permeability tests. SEM images showed that there was a functional adhesion layer between the CH and the COC, while a detachment occurred for bilayer films with GSE. The formation of a COC layer on the CH surface with the addition of NC improved the water vapor permeability, while the addition of GSE had an adverse effect on the water vapor permeability. The addition of NC into the CH films reduced their water uptake and solubility. The CH film surface showed lower contact angle values, whereas higher contact angle values were observed for CH film surfaces with GSE and NC. The inclusion of NC resulted in an increased elastic modulus and a decrease in TS and ε (%) values. All film samples showed antimicrobial activity against Escherichia coli and Listeria monocytogenes. Moreover, film samples with added GSE showed antioxidant properties with 2,2‐Diphenyl‐1‐picrylhydrazyl scavenging activity ranging from 14.33 ± 0.24 to 20.45 ± 0.07%. The bilayer films will have a potential use in transferring functional compounds as an active packaging material layer along with conventional polymers.