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Mechanics of Homeotropically Ordered Smectic‐A Elastomers with Global Oblate Chain Conformation
Author(s) -
Kramer Dominic,
Finkelmann Heino
Publication year - 2011
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.201100259
Subject(s) - elastomer , materials science , rubber elasticity , lamellar structure , isotropy , polymer , anisotropy , elasticity (physics) , molar mass , liquid crystal , composite material , modulus , phase (matter) , polybutadiene , natural rubber , copolymer , physics , optics , optoelectronics , quantum mechanics
Smectic‐A elastomers combine one‐dimensional translational order of rod‐like segments with the rubber elasticity of a polymer network. In recent years, detailed investigations were carried out on elastomers showing a global prolate chain conformation. In this communication, the first experiments on fluorinated S A elastomers exhibiting a global oblate chain conformation are presented, where the polymer chains are on average compressed along the layer normal of the lamellar phase structure. The mechanical anisotropy is studied by means of thermoelastic experiments and stress–strain measurements. For the first time, the layer compression modulus B of smectic elastomers is directly measured. B is significantly larger as compared to conventional low molar mass liquid crystals and decreases significantly with increasing local disorder introduced by the isotropic crosslinker.