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Synthesis and Properties of Unsymmetric Dimesogenic Liquid Crystal Compounds Containing Lateral Substituent

측면에 치환기를 포함하고 있는 비대칭 이메소젠 액정화합물의 합성 및 성질

  • Park, Jong-Ryul (Division of Advanced Materials Science and Engineering, Kongju National University) ;
  • Cho, Kuk Young (Division of Advanced Materials Science and Engineering, Kongju National University) ;
  • Bang, Moon-Soo (Division of Advanced Materials Science and Engineering, Kongju National University)
  • 박종률 (공주대학교 신소재공학부) ;
  • 조국영 (공주대학교 신소재공학부) ;
  • 방문수 (공주대학교 신소재공학부)
  • Received : 2015.02.28
  • Accepted : 2015.04.08
  • Published : 2015.06.10

Abstract

Two series of unsymmetric dimesogenic compounds containing a butylene or pentamethylene group as the flexible spacer were synthesized and their thermal and mesomorphic properties were studied. Mesogenic groups of the synthesized compounds consisted of a cholesteryl and an azobenzene group with lateral substituent. Chemical structures and mesomorphic properties of the synthesized compounds were investigated by FT-IR, $^1H$-NMR, differential scanning calorimeter (DSC), and polarizing optical microscope (POM). All synthesized compounds, apart from $D5-OCH_3$, showed enantiotropic liquid crystal phases. Compounds having an even number of carbon atoms in the flexible spacer exhibited wide mesophase temperature ranges and high isotropic transition temperatures. Regarding the effect of lateral substituents, compounds with bulky substituents exhibited decreased mesophase temperature ranges and isotropic transition temperatures, while those with polar substituents showed the increased thermal stability of the smectic phase.

Keywords

azobenzene;cholesteryl;dimesogenic liquid crystal;lateral substituents;unsymmetric

Acknowledgement

Grant : 리튬이차전지 산화물 코팅 분리막(두께 < 18 um)을 위한 고접착 수계바인더, 슬러리(접착강도 > 100 gf/cm) 및 코팅기술 개발

Supported by : 한국산업기술평가관리원

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