SHEAR RHEOLOGY AND SHEAR-INDUCED TEXTURES OF A THERMOTROPIC COPOLYESTERAMIDE

The textures and the rheological behavior of a thermotropic copolyeste ramide are characterized over five decades of shear rate. Three textur es are observed, one thread-like, one worm-like characterized by a lar ge density of defects and third, an ordered one characterized by a hig h flow orientation. The transitions from one texture to another depend on both shear rate and shear strain. Each texture corresponds to a gi ven flow mechanism, similar to the ones found for lyotropics, and in q ualitative agreement with the numerical predictions obtained from the rodlike solution model of Doi.