標題: Effect of a lateral substituent on the mesomorphic properties of ferroelectric side chain liquid crystalline polysiloxanes
作者: Hsu, CS
Tsai, CH
交大名義發表
應用化學系
National Chiao Tung University
Department of Applied Chemistry
公開日期: 1-六月-1997
摘要: The synthesis of side chain liquid crystalline polysiloxanes containing oligooxyethylene spacers and (S)-2-methylbutyl 4-[(4-oxybiphenyl-4'-yl)carbonyloxyl-3-fluorobenzoate mesogenic side groups is presented. Differential scanning calorimetry, optical polarizing microscopy and X-ray diffraction measurements reveal liquid crystalline properties for all synthesized monomers and polymers. All three precursor olefinic monomers reveal cholesteric and smectic A phases. The olefinic monomer which contains two oligooxyethylene units in the spacer is the only one which reveals a twist grain boundary A phase and a blue phase, besides the cholesteric and smectic A phases. All three polysiloxanes present enantiotropic smectic A and chiral smectic C phases. The mesomorphic behaviours of the monomers and polymers are compared with those of the corresponding monomers and polymers without the lateral fluoro substituent. The results seem to demonstrate that incorporating a lateral fluoro substituent in the mesogenic cores of the monomers affects not only the mesophase thermal stability, but also the nature of the mesophases formed. However, incorporating a lateral fluoro substituent in the mesogenic cores of the polymers affects only the thermal stability of the mesophases formed. The lateral fluoro substituent has a more profound effect on the mesomorphic behaviour for the monomers than that for the polymers.
URI: http://hdl.handle.net/11536/526
ISSN: 0267-8292
期刊: LIQUID CRYSTALS
Volume: 22
Issue: 6
起始頁: 669
結束頁: 677
顯示於類別:期刊論文


文件中的檔案:

  1. A1997XB94700001.pdf