Kinetic dissolution measurement of polymers by solution viscosity recording

Abstract

A laboratory device for continuous dissolution measurement of polymers by solution viscosity recording is described. The nonlinear viscosity dependence on the polymer content in the solution is utilized to measure the dissolution by recording the driving motor power of the discs rotating within the solution. A short theoretical background of the diffusion process of dissolution is introduced, with comments. The diffusion coefficient of the solvent into the polymer, velocity of dissolution, thickness of the surface swollen layer and other kinetic and activation parameters can be calculated by treating the recalibrated viscosity data. Some results of the dissolution in water of carboxymethylcellulose and some dissolution tests of the degree of fixation of textile materials are given together with suggestions for possible alternative applications.