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Rheo-Optics of an Augned Thermotropic Liquid Crystalline Polymer

Published online by Cambridge University Press:  25 February 2011

Mohan Srinivasarao
Affiliation:
Department of Polymer Science and Engineering University of Massachusetts, Amherst, MA 01003
Raul O. Garay
Affiliation:
Department of Polymer Science and Engineering University of Massachusetts, Amherst, MA 01003
H. Henning Winter
Affiliation:
Department of Polymer Science and Engineering University of Massachusetts, Amherst, MA 01003
Richard S. Stein
Affiliation:
Department of Polymer Science and Engineering University of Massachusetts, Amherst, MA 01003
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Abstract

Rheo-optical studies on aligned and unaligned melts of a main chain thermotropic polyester with flexible spacers are discussed in terms of the predictions of the Ericksen-Leslie equations. It is shown, using conoscopy, that the director is flowaligning at temperatures close to TNI and nonflow-aligning close to a smectic to nematic (TSN) phase transition. The implications of these results are discussed in terms of the change in sign of one of the Leslie viscosity coefficients and interpreted in the framework of the Ericksen-Leslie Theory.

Type
Research Article
Copyright
Copyright © Materials Research Society 1992

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