Progress and Research of the Abnormal Viscosity Behavior of Polymer Solution at Extremely Dilute Concentration

To obtain the intrinsic viscosity of polymer solution, the reduced viscosity of polymer solution at dilute concentrations, should be extrapolated linearly to zero concentration. The reasonableness to determine the intrinsic viscosity according to this method depends on the assumption that the linear relationship between the reduced viscosity and concentration should be existed even in extremely dilute polymer solution. In this paper, the influence of the polymer layer adsorbed on the viscometer capillary wall, wall effect, the change of flow model of polymer solution or solvent, the interaction between polymer molecules and wall surface, and the construct limitation of the Ubbelohde viscometer upon the viscosity of polymer solution at extremely dilute concentrations was introduced. Peculiarly, the novel methods to determine the viscosity of polymer solution at extremely dilute concentrations were presented in detail.