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

Abstract

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.

References

  1. J. Salamone, 'Polymetric Materials', ed. by C. D. Eisenbach, p.6957, Boca Raton, New York, 1996
  2. P. J. Collings, 'Liquid crystals', ed. by P. J. Collings, p.3, Princeton University Press, 1990
  3. P. J. Collings, M. Hird, 'Introduction to Liquid Crystals', Taylor & Francis Ltd, London, 1997
  4. 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)
  5. T. Uryu, and T. Kato, 'Solid-State Cross polarization/ Magic Angle Spinning $^{13}C$ NMR Study of Thermotropic Aromatic Polyester Containing a Flexible Spacer in The Main Chin', Macromolecules, 21, 378 (1988)
  6. H. S. Lee, W. H. Jung, W. N. Kim, and J. C. Hyun, 'Properties of Blends of Polycarbonate and Thermotropic Liquid Crystalline Polymer', Polymer (Korea), 29, 813 (1996)
  7. W. Mormann and M. Brahm, 'Polymers from Multfunctional Isocyanates', Macromolecules, 24, 1096 (1991)
  8. P. Penczek, K. C. Frisch, B. Szczepaniak, and E. Rudnik, 'Synthesis and Properties of Liquid Crystalline Polyurethanes', J. Polym. Sci., Part A: Polym. Chem., 31, 1211 (1993)
  9. C. H. Lin, J. F. Kuo, and C. Y. Chen, 'Synthesis and mesomorphism of thermotropic liquid crystalline polyurethanes based on meta-diisocyanates with 4,4 '-bis($\omega$-hydroxyalkoxy)biphenyls', European polymer journal, 36, 1183 (2000)
  10. K. Iimura, N. Koide, H. Tanabe, and M. Takeda, 'Syntheses of Thermotropic Liquid Crystalline Polymers', Makrmol. Chem., 182, 2569 (1981)
  11. M. Tanaka, and T. Nakaya, 'Liquid crystalline Polyurethanes', Makromol. Chem., 187, 2345 (1986)
  12. P. J. Stenhouse, E. M. Valles, S. W. Kantor, and W. J. MacKnight, 'Thermal and Rheological Properties of a Liquid-Crystalline polyurethane', Macromolecules, 22, 1467 (1989) https://doi.org/10.1021/ma00193a077
  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($\omega$-hydroxyalkoxy)biphenyls', Macromolecules, 26, 4989 (1993)
  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)
  15. D. J. Lee, J. B. Lee, N. Koide, E. Akiyama, and T. Uryu, 'Liquid Crystallinity of Thermotropic ParaType Home- and Copolyurethanes containing Biphenylene Mesogen and Their Blends', Macromolecules, 31, 975 (1998)
  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)
  17. J. B. Lee, 'Thermal Properties of Liquid-Crystalline Polyurethanes Containing Biphenylene Mesogenic Unit', J. Ind Eng. Chem., 6, 338 (2000)
  18. J. B. Lee, 'The Effect of Substituents on the Liquid Crystalline Behavior of Polyurethanes', J. Korean Ind Eng. Chem., 12, 649 (2001)
  19. J. B. Lee, 'Synthesis and Properties of Biphenylene Mesogen Containing 4,4' -bis($\omega$-hydroxyalkoxy)biphenyls', J. Korean Ind Eng. Chem., 13, 654 (2002)