Rheological properties of nanocomposite-forming solutions and film based on montmorillonite and corn starch with different amylose content.

Nanoparticles (montmorillonite, MMT) can enhance biopolymer-based film properties. The structure-property relationship between polymers and nanoparticles may be explained by the rheological tests of nanocomposite forming solutions (NFS). The aim of this work was to study the effect of MMT concentration and amylose content on the rheological properties of NFS based on corn starch and glycerol following two preparation methods, through steady shear and dynamic tests. The organization level of NFS was influenced by the addition order of the components. Decreasing in flow index behavior when increasing amylose content was attributed to interactions between the starch components. In all NFS, G' was higher than G″ indicating a gel-like behavior and suggesting that the MMT reinforced the starch matrix as observed by the increase in the storage modulus of films with MMT. Films obtained from method 2 have better mechanical properties probably due to the starch-MMT interactions.