Rotational Viscosities of Polymer Solutions in a Low Molecular Weight Nematic Liquid Crystal

Abstract

Abstract Polystyrene polymers (M.W. - 2700) were dissolved in a low molecular weight nematic mixture E63 (E. Merck) in different concentrations, and studied over a broad temperature range. The rotational viscosities, γb of the mixtures were measured by using the rotating magnetic field method. Contrary to the theoretical indications and some earlier experimental results, it was found that the rotational viscosity is practically not influenced due to the polymers, which suggests that the polymer conformation is rather spherical in the anisotropic fluid. Preliminary investigations of the flow properties (capillary flow) show that the effective shear viscosity increase due to the added polymer is similar to that of isotropic solutions.