Abstract
It is well known that the viscosity of polymer solutions is strongly dependent on the polymer molecular weight and concentration, as well as chain stiffness. Experimental zero-shear viscosity data for five polymer solution systems with different chain stiffness over wide ranges of polymer molecular weight and concentration are compared with a viscosity equation formulated on the basis of wormlike-cylinder and fuzzy-cylinder models. The viscosity equation contains adjustable parameters representing the strength of intermolecular hydrodynamic interaction, which cannot be calculated by molecular theory. When suitable values are chosen for these adjustable parameters, the results of the viscosity equation are favorably compared with the experimental data of the five polymer solution systems.