Synthesis and Characterization of New Thermotropic Liquid Crystalline Polyurethanes with Naphthalene Moiety

나프탈렌기를 갖는 새로운 액정폴리우레탄의 합성 및 특성

  • Lee, Jong-Baek (Department of Chemical Engineering, Dongeui University) ;
  • Lee, Kwang-Hyun (Department of Chemical Engineering, Dongeui University)
  • 이종백 (동의대학교 화학공학과) ;
  • 이광현 (동의대학교 화학공학과)
  • Published : 2005.03.31


Novel polyurethanes containing no mesogenic unit were synthesized by the polyaddition reaction of para-type diisocyanates such as 2,5-tolylene diisocyanate (2,5-TDI) or 1,4-phenylene diisocyanate (1,4-PDI) with 2,6-bis(${\omega}$-hydroxyalkoxy)naphthalene (BHNm; m= 5, 6, 8, 11). Intrinsic viscosities of the polymers were in the range of 0.28-0.43 dL/g. The thermal properties of these polymers were studied by differential scanning calorimetry and polarizing microscopy. Polyurethanes prepared from BHNm and 2,5-TDI haying methyl substituent on the phenylene unit exhibited monotropic liquid crystallinity. However, in the series of polyurethanes prepared from 1,4-PDI and BHNm, no explicit mesomorphic behavior was observed by differential scanning calorimetry and polarizing microscopy.


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