The phase state and rheological properties of chitosan-acetic acid-water systems

The phase state and rheological properties of the chitosan-acetic acid-water ternary system were studied over a wide composition range. The proportion of acetic acid was shown to affect the solvent power, viscosity, viscous-flow activation energy E a , and stability of dilute and concentrated chitosan solutions in a non-monotonic manner. The maximum intrinsic viscosity was observed for solutions in 10% acetic acid, but the relative and the dynamic viscosity of semidilute (1-3%) solutions show maximum values for acetic acid concentrations of 2 and 70-77%. Reasons for the observed behavior are discussed.