Physicochemical properties of starch–CMC–nanoclay biodegradable films

Novel citric acid (CA) modified starch–carboxymethyl cellulose (CMC)–montmorillonite (MMT) bionanocomposite films were prepared by casting method. X-ray diffraction (XRD) test showed that the 0 0 1 diffraction peak of nanoclay was shifted to lower angles in the bionanocomposites and it may be implied that the clay nanolayers formed an intercalated structure. However, completely exfoliated structure formed only in the pure starch–MMT nanocomposites (without CA and CMC). At the level of 7% MMT, the composite films showed the lowest solubility (7.21%). The MMT addition at content of 7% (w/w), caused to increase in ultimate tensile strength (UTS) by more than threefold in comparison to starch–CMC biocomposites.