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A New Type of Macroscopically Oriented Smectic‐ A Liquid Crystal Elastomer
Author(s) -
Komp Ansgar,
Finkelmann Heino
Publication year - 2007
Publication title -
macromolecular rapid communications
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.348
H-Index - 154
eISSN - 1521-3927
pISSN - 1022-1336
DOI - 10.1002/marc.200600640
Subject(s) - lamellar structure , perpendicular , elastomer , materials science , liquid crystal , rubber elasticity , deformation (meteorology) , elasticity (physics) , crystallography , composite material , thermoelastic damping , condensed matter physics , mesogen , natural rubber , polymer , physics , geometry , liquid crystalline , chemistry , thermodynamics , mathematics , optoelectronics , thermal
Smectic‐ A liquid single crystal elastomers (S A ‐LSCE) are materials where the rubber elasticity of the polymer network is combined with the one‐dimensional positional long‐range order of mesogenic groups which are covalently attached to the network. In the systems investigated so far, a mechanical deformation of the network causes significant reorientation processes of the layered structure. We present a new type of S A ‐LSCE in which this structure remains unaffected on mechanical deformation both parallel and perpendicular to the director. The thermoelastic behavior, macroscopic dimensions, and stress–strain measurements parallel as well as perpendicular to the director are investigated. X‐ray studies confirm that a deformation parallel and perpendicular to the layer normal does not alter the macroscopically ordered lamellar structure with respect to the order parameter and the layer correlation length. We propose a simple picture where defects within the lamellar structure might account for these findings.