SHEAR RHEOLOGY AND SHEAR-INDUCED TEXTURES OF A THERMOTROPIC COPOLYESTERAMIDE

The textures and the rheological behavior of a thermotropic copolyesteramide are characterized over five decades of shear rate. Three textures are observed, one thread-like, one worm-like characterized by a large density of defects and third, an ordered one characterized by a high flow orientation. The transitions from one texture to another depend on both shear rate and shear strain. Each texture corresponds to a given flow mechanism, similar to the ones found for lyotropics, and in qualitative agreement with the numerical predictions obtained from the rodlike solution model of Doi.