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Side‐chain Cholesteric Liquid Crystalline Elastomers Derived from Nematic Bis‐olefinic Crosslinking Units
Author(s) -
Zhang BaoYan,
Hu JianShe,
Jia YingGang,
Du BingGuang
Publication year - 2003
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.200350072
Subject(s) - elastomer , differential scanning calorimetry , monomer , materials science , liquid crystal , polymer chemistry , side chain , fourier transform infrared spectroscopy , phase (matter) , glass transition , chemical engineering , crystallography , polymer , chemistry , composite material , organic chemistry , thermodynamics , physics , optoelectronics , engineering
The synthesis of the nematic crosslinking agent (4′‐allyloxy‐benzoyl)‐(4″‐undec‐10‐en‐1‐oyl‐benzoyl)‐ p ‐benzenediolate ( M ‐ 1 ), the cholesteric monomer cholesteryl undec‐10‐en‐1‐oate ( M ‐ 2 ) and side‐chain cholesteric liquid crystalline elastomers is described. The chemical structures of the obtained monomers and elastomers were confirmed by FTIR and 1 H NMR spectroscopy. Their mesomorphic properties and phase behavior were investigated by differential scanning calorimetry, polarizing optical microscopy, and X‐ray diffraction measurements. The influence of the crosslinking M ‐ 1 units on phase behavior of different elastomers prepared by a one‐step hydrosilation reaction was discussed. The elastomers containing less than 20 mol‐% of the crosslinking M ‐ 1 units showed elasticity, reversible phase transition and cholesteric texture. The experimental results demonstrated that the glass transition temperatures and isotropization temperatures of P ‐ 2 ∼ P ‐ 6 increased with increasing the concentration of crosslinking M ‐ 1 units.Synthesis and schematic representation of elastomers.