• Synthesis and Characterization of Wholly Aromatic Polyester Liquid Crystalline Thermosets
  • Moon HG, Jung MS, Chang JH
  • 전방향족 폴리에스터 열경화성 액정의 합성과 특성
  • 문현곤, 정명섭, 장진해
Abstract
We prepared a series of aromatic liquid crystals (LCs) based on wholly aromatic ester units with the reactive end group methyl maleimide by means of melt condensation method, and the resulting LCs were thermally crosslinked to produce liquid crystalline thermoset (LCT) films. The synthesized LCs and LCTs were characterized with Fourier transform infrared (FTIR) spectroscopy, wide angle X-ray diffraction (WAXD), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), thermomechanical analysis (TMA), and polarizing optical microscopy (POM) with a hot stage. The glass transition temperature (Tg) and coefficient of thermal expansion are strongly affected by the mesogen units in their main chain structures. The p-substituted biphenyl LC was found to have the highest thermal property value.

용융법을 이용해서 말단에 가교 반응이 가능한 메틸 말레이미드(methyl maleimide)기를 가진 전방향족 에스터 결합의 액정(liquid crystal, LC)을 합성하였고, 합성된 LC를 이용해서 적당한 열처리 과정을 통해 열경화성 액정(liquid crystalline thermoset, LCT) 필름을 제조하였다. 합성된 LC 및 LCT 필름은 FTIR(Fourier transform infrared) 분광기, WAXD(wide angle X-ray diffraction), DSC(differential scanning calorimetry), TGA(thermogravimetric analysis), TMA(thermomechanical analysis), 그리고 가열판이 장착된 편광 현미경으로 특성 분석을 하였다. 유리전이온도(Tg)와 열팽창 계수는 주사슬 구조의 메소겐에 의해 강한 영향을 받는 것으로 확인되었고, para-로 치환된 비페닐 구조를 가진 LCT 필름이 가장 좋은 열적 성질을 보여 주었다.

Keywords: liquid crystal; liquid crystalline thermoset; thermal property; coefficient of thermal expansion.

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This Article

  • 2012; 36(1): 9-15

    Published online Jan 25, 2012

  • Received on Apr 29, 2011
  • Accepted on Jul 4, 2011