Studying morphological and moisture barrier properties of Starch - CMC - nanoclay biodegradable bionanocomposite film

In order to improve the properties of the starch biodegradable films, three components were manipulated: citric acid, carboxy methyl cellulose (CMC) and nanoclay, and the effect of each of these ingredients on the morphological properties and roughness values of the films, as well as their homogeneity were investigated. Afterwards, the effect of nanoclay concentration on the moisture permeability of these films was investigated. AFM results indicated that the starch – CMC biocomposites and starch – CMC – nanoclay bionanocomposites had the lowest and highest roughness values, respectively. Results of the moisture adsorption test indicated that by increasing the nanoclay contents, moisture absorption of the films decreased. The films containing 7% nanoclay showed the lowest moisture absorption value (14.78%). However, according to the results of contact angle test, surface hydrophobisity of the films decreased by an increase in nanoclay contents.