Non-Newtonian Flow of Structured Systems. XX. The Viscosity of Polymer Solutions

Abstract
Curves of viscosity and curves of polymer solutions’ flow (xanthan, nitrocellulose, λ-carrageenan, sodium carboxymethylcellulose, polyacrylamide) are considered. The article show that for some polymer solutions generalized flow equation is valid in a wide interval of shear rates (up to seven orders of magnitude), at very low shear rates (up to 10^–4 s^–1). It is shown that two regimes of flow can to be coexisted on a wide range of shear rate. It was found that the coefficient of aggregation τ_c^1/2 is almost independent of the temperature, the coefficient of viscosity of Casson η_c^1/2 is reduced, and coefficient of compactness χ increases with increasing of temperature. These results are consistent with the conclusions of the structural rheological model.

Keywords: polymer solutions, structural rheological model, flow regimes, the coefficients of generalized flow equation