화학공학소재연구정보센터
Molecular Crystals and Liquid Crystals, Vol.625, No.1, 47-54, 2016
Mesomorphism dependence on molecular rigidity
A novel ester homologous series of thermotropic liquid crystal (LC) has been studied with a view to understanding and establishing the relation between LC property and the molecular structure. The series consists of 11 members, the C-1-C-5 and C-16 members of the series are nonliquid crystals. LC properties commence from the C-6 homolog and continue up to the C-14 homolog as enantiotropic nematic and smectic in addition to nematic. Transition temperatures of the homologs were determined by an optical polarizing microscope equipped with a heating stage. Textures of nematic phase are threaded or Schlieren and that of smectic is focal conic of the type-A. Analytical and spectral data confirm the structures of homologs. Thermal stability for nematic is 93 degrees C and 136 degrees C, respectively. The N-I and Sm-N transition curves of phase diagram do not exhibit odd-even effect. The N-I transition curve partly behaves in an abnormal manner. The Cr-I and Sm-N transition curves behave in normal manner. The LC behavior of the present series is compared with structurally similar known homologous series.