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Breakdown of Layering in Frustrated Smectic‐A Elastomers
Author(s) -
Kramer Dominic,
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.200700557
Subject(s) - materials science , elastomer , perpendicular , layering , rubber elasticity , deformation (meteorology) , composite material , elasticity (physics) , small angle x ray scattering , phase (matter) , liquid crystal , condensed matter physics , polymer , optics , scattering , geometry , chemistry , physics , botany , mathematics , optoelectronics , biology , organic chemistry
Smectic‐A elastomers combine the positional long‐range order of mesogenic molecules in one dimension with the rubber elasticity of a polymer network. Upon mechanical deformation, completely different responses of the phase structure have been reported. We present a highly distorted system which shows a breakdown of smectic layering but no reorientation under deformation along the layer normal, while the phase structure stays unaffected under uniaxial stress in the perpendicular direction. The thermoelastic properties, macroscopic dimensions and stress–strain behaviour are investigated parallel and perpendicular to the layer normal. SAXS measurements supply evidence for a breakdown of the macroscopically ordered layer structure indicated by the small angle intensities and correlation length, whereas the orientational order is preserved. We propose defects in the smectic layer structure to be the origin of the different responses of different smectic elastomers.