Effect of addition of cellulose powder on the viscometric behavior of liquid crystalline solutions of ethyl cellulose in m-cresol

Steady-state shear viscosity for the liquid crystalline ethyl cellulose solution filled with cellulose powders was determined using a cone-plate-type viscometer and the effects of cellulose powder content, powder aspect ratio and temperature on the viscometric behavior and phase transformation were discussed. The addition of powder increased the viscosity and decreased the activation energy (E_a) for flow, but did not affect the phase transformation. The viscosity and E_a depended on the aspect ratio; with greater aspect ratio, the viscosity enhancement was accelerated and E_a as well as the decrease in E_a with powder content increased. The phase transformation did not depend on the aspect ratio, the dependences of viscosity and of E_a on powder content depended on the solution phase; the dependences for the anisotropic phase were smaller than those for the isotropic one. The findings appeared to originate from the alignments of powders and rod-like molecules.