proceedings article

Abstract

The pressure profile of the thermotropic LCP Vectra A900 measured in a slit die rheometer is not linear. The non-linearity can not be explained by a model in which the orientation of the LCP imposed by the entry flow is reduced by the tumbling of the molecules in the subsequent shear flow. The combination of a concave shape Bagley plot and an idem shaped pressure profile indicates an effect of the pressure on the viscosity. When this pressure dependence is taken into account the viscosity measured in the slit rheometer coincides with the one measured in the capillary.

Progress and Trends in Rheology, IV, 494, 1994

Rheology of thermotropic liquid crystalline polymers: slit rheometer measurements