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Preparation and Properties of Cholesteric Network Polymers Based on Liquid Crystalline Epoxides
Author(s) -
Hartwig Andreas,
Mahato Tapan Kumar,
Kaese Torsten,
Wöhrle Dieter
Publication year - 2005
Publication title -
macromolecular chemistry and physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.57
H-Index - 112
eISSN - 1521-3935
pISSN - 1022-1352
DOI - 10.1002/macp.200500198
Subject(s) - superstructure , polymer , cationic polymerization , liquid crystal , materials science , absorption spectroscopy , crystallography , polymer chemistry , absorption (acoustics) , chemistry , photochemistry , optics , composite material , physics , thermodynamics , optoelectronics
Summary: Polyether network polymers with cholesteric superstructure are formed by the photochemically induced cationic copolymerisation of a nematic diepoxide with chiral epoxides. If a cholesteric superstructure is formed or not, depends on the temperature at which the photopolymerisation is carried out. The storage modulus is higher above T G in samples with cholesteric superstructure. Optical rotations and vibrational circular dichroism spectra (VCD) depend strongly on the surface state of the substrates. From the VCD spectra it is concluded that the copolymerisation leads to different superstructures depending on the rub directions of the substrates.IR absorption spectrum and VCD spectrum of the cholesterol derivative 4 .