Miscibility and physical properties of chitosan and silk fibroin mixtures

Miscibility investigations of chitosan (Ch) with silk fibroin (SF) mixtures with different weight percentage compositions (100/0, 80/20, 50/50, 20/80, 0/100) were studied using viscometric method. The viscosity interaction parameter of each polymer in 0.1 mol.dm(-3) solution as well as the ternary systems (polymer A, polymer B/solvent) has been determined. By comparing the experimental and ideal viscosity data it was clearly seen that the investigated system are miscible at the weight fraction of chitosan in the mixtures W-Ch <= 0.5. Ch, SF and their mixture films were prepared by casting technique. The effect of mixture composition on mechanical and thermal properties was also investigated in this study. The mechanical properties such as ultimate tensile strength, Young modulus and tensile strain at break depend on the weight fraction of chitosan and were changed irregularly. The thermal properties of the film made of Ch/SF mixtures were similar to those of chitosan film. (C) 2014 Elsevier B.V. All rights reserved.