J. Phys. II France
Volume 4, Numéro 8, August 1994
Page(s) 1363 - 1373
DOI: 10.1051/jp2:1994204
J. Phys. II France 4 (1994) 1363-1373

Chain conformation in nematic elastomers

H. Finkelmann1, W. Kaufhold1, L. Noirez2, A. ten Bosch3 and P. Sixou3

1  Institut für Makromolekulare Chemie, Universität Freiburg, 7800 Freiburg, Germany
2  Laboratoire Léon Brillouin, CEN Saclay, 91191 Gif-sur-Yvette Cedex, France
3  Laboratoire de Physique de la Matière Condensée, Parc Valrose, 06034 Nice Cedex, France

(Received 24 March 1993, revised 12 April 1994, accepted 4 May 1994)

The anisotropy of the main chain conformation of a side-on fixed liquid crystal elastorner on application of a mechanical stress has been measured in the isotropic and nematic phases by small angle neutron scattering. The radii of gyration parallel and perpendicular to the stress field have been determined on elongation and as a function of temperature. A weak anisotropy of the main chain conformation is found only in the nematic phase at sufficiently high values of elongation. A comparison to a theory based on a Landau de Gennes expansion of the free energy for oriented monodomain samples which includes coupling between elastic deformation and nematic strain is made.

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