The Non-Newtonian Viscosity of Dilute Aqueous Solution of Methylcellulose

Abstract

Abstract The viscometric behavior of a dilute aqueous solution of methylcellulose was studied by tilting capillary viscometers. The intrinsic viscosity was obtained by the extrapolation of Martin’s plots on the assumption that the plots were linear down to an infinite dilution. The intrinsic viscosity obtained increased with the rate of shear over the range of 200–1200 sec−1. Huggins’ constant, k′, the temperature coefficient of the intrinsic viscosity, d[η]/dT, and the energy of the activation of flow, Ev, decreased with the rate of shear. From the data of d[η]/dT and Ev thus obtained, it has seemed reasonable to assume that the methylcellulose chain has a relatively small flexibility and a strong tendency toward alignment with a flowing stream. This may be the main reason why the viscosity of the dilute aqueous solution of methylcellulose is non-Newtonian.