Cooperative performance of chitin whisker and rectorite fillers on chitosan films

We prepared chitosan/chitin whisker/rectorite ternary films and studied the cooperative effects of nanofibril whisker and layered organic rectorite on the properties of chitosan matrix. The ternary film exhibited higher thermal stability and smoother surface than the whisker or rectorite reinforced binary films due to the intercalation of chitosan chains into the layered rectorite and the impregnation between the clay and rod-like whisker. With increasing the ratio of mixed fillers from 0 to 229 mg/g, the break elongation first increased to a maximum value (144%) with the mixed fillers of 114.5 mg/g and then decreased. Antimicrobial assay against Escherichia coli and Staphylococcus aureus showed that the ternary films had higher antimicrobial effect than the pure or binary films because of the significant adsorption capacities of the enlarged interlayer of rectorite. Overall, the chitosan-based ternary film with chitin whisker and rectorite proves to be a suitable material for food-packaging applications. (C) 2011 Elsevier Ltd. All rights reserved.