Zero-Shear Viscosities of Polysaccharide Solutions

Abstract

Solution viscosities are strongly dependent on the molecular weight, the concentration, and the chain conformation of polymers added. We have formulated the intrinsic viscosity [η] at infinite dilution and the zero-shear viscosity η at finite concentrations using the molecular theory based on the wormlike chain and fuzzy cylinder models. In the theory, the solution viscosity at finite concentrations is affected by both hydrodynamic and entanglement interactions. The formulated viscosity equations quantitatively predict [η] and η as functions of the wormlike chain parameters and the strength of the hydrodynamic interaction and demonstrated that the relative importance of the hydrodynamic and entanglement interactions in the solution viscosity depends on the chain stiffness. We have compared the formulated viscosity equations with experimental results for solutions of three polysaccharides and two synthetic polymers covering a wide range of the chain stiffness.