Peculiarities of viscometric studies of enzymatic hydrolysis of chitosan

Abstract

Enzymatic hydrolysis of chitosan (CTS) is studied by viscosity measurements, velocity sedimentation, and diffusion. It is found that the incubation of CTS in acetic acid solution is always accompanied by a decrease in the relative and intrinsic viscosity of CTS, but the chains are not destroyed in the process, as evidenced by the coincidence of the sedimentation constant and diffusion coefficient values with the values obtained for the initial CTS samples. The addition of enzymatic agents to the CTS solution results in a significant decrease in the sedimentation constant and an increase in the diffusion coefficient, indicating a decrease in molecular weight and the proceeding of enzymatic hydrolysis. Thus, the pattern of changes in the solution viscosity indexes, which can be affected by supramolecular structures of the polymer solution, has to be taken into account when using viscosity measurements.