Pujolle-Robic, C., Olmsted, P.D. and Noirez, L. (2002) Transient and stationary flow behaviour of side chain liquid-crystalline polymers: Evidence of a shear-induced isotropic-to-nematic phase transition. Europhysics Letters, 59 (3). pp. 364-369. ISSN 1286-4854Full text available as:
Available under licence : See the attached licence file.
This letter describes the non-linear rheology of the isotropic phase of a thermotropic side chain liquid-crystal polymer (SCLCP), from which we infer a flow-induced iso- tropic-to-nematic (IN) phase transition above a critical shear stress and construct non-equilib- rium phase diagrams. In contrast to the well-studied wormlike-micellar solutions and predictions for simple liquid-crystalline systems, the critical stress does not vanish as the equilibrium transition temperature is approached from the above. We postulate that this is due to: i) the coupling between mesogens and the polymer backbone, whose equilibrium oblate nematic backbone conformation contrasts with the prolate non-equilibrium conformation; and ii) the peculiar topological constraints in SCLCP melts, which have been previously postulated as leading to long-lived clusters.
|Copyright, Publisher and Additional Information:||© 2002 EDP Sciences. Reproduced in accordance with the publisher's self-archiving policy.|
|Institution:||The University of Leeds|
|Academic Units:||The University of Leeds > Faculty of Maths and Physical Sciences (Leeds) > School of Physics and Astronomy (Leeds)
The University of Leeds > University of Leeds Research Centres and Institutes > Interdisciplinary Research Centre in Polymer Science and Technology (Leeds)
|Depositing User:||Repository Officer|
|Date Deposited:||08 Feb 2007|
|Last Modified:||04 Jun 2014 23:26|