A RHEOLOGICAL STUDY OF SOLUTIONS OF NITROCELLULOSE

Abstract

By using a MacMichael viscometer the change in viscosity at various rates of shear was determined for solutions of various types of nitrocellulose in the solvents; acetone, n-butyl acetate, Hercules' mixed solvent, and dibutyl phthalate. It was found that all solutions of low intrinsic viscosity nitrocellulose were dilatant in dilute solution, while those of high intrinsic viscosity were thixotropic. Thixotropy also changed with concentration, the solutions studied going from dilatant to thixotropic through Newtonian types on increasing the concentration. Thixotropy and dilatancy were both found to decrease as the temperature increased. At a given concentration, both the viscosity and the structural viscosity of solutions varied with solvent, dibutyl phthalate giving both the highest viscosity figures and the greatest effect on structural viscosity.