Elastomers and Composites

The Rubber Society of Korea (한국고무학회)
권호 표지

Synthesis and Characterization of New Main Chain Liquid Crystalline Coumarin Compound with Ester Moiety

Ester기를 갖는 새로운 주쇄형 액정 coumarin 화합물의 합성 및 특성분석

  • Lee, Jong-Back (Department of Chemical Engineering, Dongeui University) ;
  • Kang, Byung-Chul (Department of Chemical Engineering, Dongeui University) ;
  • Lee, Gang-Choon (Department of Chemical Engineering, Dongeui University) ;
  • Lee, Dong-Jin (Korea Institute of Ceramic Engineering & Technology) ;
  • Hideyuki, Kihara (Nanotechnology Research Institute, National Institute of Advanced Industrial Science and Technology (AIST))
  • Published : 2009.12.31
Download PDF
⟨ Previous Next ⟩

Abstract

4-(6-bromohexyloxy)benzoic acid was synthesized from benzyl 4-Hydroxybenzoate and 1,6-dibromohexane. It was reacted with hydroquinone to obtain a new mesogenic ester having an bromine group. One kind of new photoresponsive coumarin compound was prepared by the reaction of mesogenic ester with coumarin sensitive to the ultraviolet. Structures of the compound were identified by FT-IR and $^1H$-NMR spectroscopies. Their phase transition temperatures and thermal stability were also investigated by differential scanning calorimetry (DSC), polarized optical microscopy (POM) and x-ray diffraction analysis. From optical polarizing microscopy, the prepared compound was found to show enantiotropic liquid crystallinity with smectic and nematic textures.

Benzyl 4-Hydroxybenzoate와 1,6-Dibromohexane을 반응시켜 4-(6-bromohexyloxy)benzoic acid를 합성하였다. 이것을 하이드로퀴논과 반응시켜 브롬 그룹을 갖는 새로운 mesogenic ester를 합성하였다. Mesogenic ester를 자외선에 민감한 coumarin과 반응시켜 새로운 형태의 광응답성 coumarin 화합물을 합성 하였다. 합성된 화합물의 구조는 FT-IR 및 $^1H$-NMR에 의해 확인 하였으며, 그들의 열적 상전이온도 및 안정성들은 DSC, 편광현미경 및 X-선 회절에 의해 조사 하였다. 한편 합성된 새로운 화합물은 광학 편광 현미경 관찰에 의해 스멕틱 및 네마틱 구조를 갖는 쌍방성 액정성을 보였다.

Keywords

References

  1. 이신두, '액정' 전파과학사, 1994
  2. 최이준, 진정일 '액정고분자' 문운당, 2001
  3. J. Salamone, 'Polymetric Materials', ed. by C. D. Eisenbach, p. 6957, Boca Raton, New York, 1996
  4. P. J. Collings, 'Liquid crystals', ed. by P. J. Collings, p. 3, Princeton University Press, 1990
  5. P. J. Collings, M. Hird, 'Introduction to Liquid crystals', Taylor & Francis Ltd, London, 1997
  6. J. I. Jin, S. Antoun, C. Ober, and R. W. Lenz, 'Thermotropic Liquid Crystalline Polyesters with Rigid or Flexible Spacer Groups', Polym. J., 12, 132 (1980) https://doi.org/10.1002/pi.4980120403
  7. H. Kihara, and N. Tamaoki, 'In situ Photochemical Conversion from Cinnamoyl-functionalized Liquid -Crystalline Monomers to Liquid-Crystalline Dimers', Liquid Crystals, 34, 1337 (2007) https://doi.org/10.1080/02678290701697454
  8. R. S. Trenor, A. R. Shultz, B. J. Love, and T. E. Long, 'Coumarins in Polymers: From Light Harvesting to Photo- Cross-Linkable Tissue Scaffolds', Chem. Rev., 104, 3059 (2004) https://doi.org/10.1021/cr030037c
  9. X. YU, D. Scheller, O. Rademacher, and T. Wolff, 'Selectivity in the Photodimerization of 6-Alkylcoumarins', J. Org. Chem., 68, 7386 (2003) https://doi.org/10.1021/jo034627m
  10. N. K. Mal, M. Fujiwara, and Y. Tanaka, 'Photocontrolled Reversible Release of Gust Molecules from Coumarin-modified Mesoporous Silica', Nature, 421, 350 (2003) https://doi.org/10.1038/nature01362
  11. Y. Tian, E. Akiyama, Y. Nagase, A. Kanazawa, O. Tsutsumi, and T. Ikeda, 'Liquid Crystalline Coumarin Polymers', Macromol. Chem. Phys., 201, 1640 (2000) https://doi.org/10.1002/1521-3935(20000901)201:14<1640::AID-MACP1640>3.0.CO;2-Z
  12. P. O. Jackson and M. O'Neill, 'An Investigation of the Role of Cross-Linking and Photodegradation of side-Chain Coumarin Polymers in the Photoalignment of Liquid Crystals', Chem. Mater., 13, 694 (2001) https://doi.org/10.1021/cm0011413
  13. J. B. Lee, T. Kato, T. Yoshida, and T. Uryu, 'Synthesis and Liquid Crystalline Properties of Thermotropic Polyurethanes Prepared from 1,4-Diisocyanates and 4,4´-Bis(ω-hydroxyalkoxy) biphenyls', Macromolecules, 26, 4989 (1993) https://doi.org/10.1021/ma00071a001
  14. J. B. Lee, T. Kato, S. Ujiie, K. Iimura, and T. Uryu, 'Thermotropic Polyurethanes Prepared from 2,5-Tolylene Diisocyanates and 1,4-Bis($\omega$-hydroxyalkoxy)benzenes Containing No Mesogenic Unit', Macromolecules, 28, 2165 (1995) https://doi.org/10.1021/ma00111a010
  15. D. J. Lee, J. B. Lee, N. Koide, E. Akiyama, and T. Uryu, 'Liquid Crystallinity of Thermotropic Para-Type Home- and Copolyurethanes containing Biphenylene Mesogen and Their Blends', Macromolecules, 31, 975 (1998) https://doi.org/10.1021/ma970866y
  16. H. M. Jeong, J. B. Lee, S. Y. Lee, and B. K. Kim, 'Shape Memory Polyurethane Containing Mesogenic Moiety', J. of Materials Sci., 35, 279 (2000) https://doi.org/10.1023/A:1004728814128
  17. J. B. Lee, 'Thermal Properties of Liquid-Crystalline Polyurethanes Containing Biphenylene Mesogen', Key Engin. Mater., 321, 1385 (2006) https://doi.org/10.4028/www.scientific.net/KEM.321-323.1385
  18. J. B. Lee, K. H. Lee, and B. C. Kang, 'Synthesis and Characterization of Thermotropic Liquid Crystalline Polyurethanes', Elastomer, 41, 108 (2006)