Synthesis and Characterization of New Thermotropic Liquid Crystalline Polyurethanes

새로운 형태의 액정폴리우레탄의 합성 및 특성

  • Published : 2006.06.30

Abstract

A series of thermotropic polyurethanes containing biphenyl units was synthesized by polyaddition reaction of diisocyanates such as 2,6-tolylene diisocyanate, 2,5-tolylene diisocyanate, 2,4-tolylene diisocyanate, 1,4-phenylene diisocyanate, and hexamethylene diisocyanate with 4,4'-Bis(9-hydroxynonoxy)biphenyl (BP9). 4,4'-bis(9-hydroxynonoxy)biphenyl exhibited a smectic type mesophase. Mesophase was found for all synthesized liquid crystalline polyurethanes except 1,4-PDI/BP9 based polyurethane. Structures of the monomer and the corresponding polymers were identified using FT-IR and $^1H-NMR$ spectroscopies. Their phase transition temperatures and thermal stability were also investigated by differential scanning calorimetry and optical polarizing microscopy.

비페닐기를 함유하는 새로운 형태의 액정성 폴리우레탄을 신규로 합성한 4,4'-Bis(9-hydroxynonoxy)biphenyl (BP9)와 2,6-tolylene diisocyanate, 2,5-tolylene diisocyanate, 2,4-tolylene diisocyanate, 1,4-phenylene diisocyanate 및 hexamethylene diisocyanate의 중부가 반응에 의해 합성하였다. 단량체 BP9은 스멕틱상을 형성하였으며 1,4-PDI/BP9을 제외한 나머지 폴리우레탄에서는 모두 액정성을 나타내었다. 합성된 단량체와 중합체들의 구조는 적외선분광분석기 및 핵자기공명분석기를 사용하여 확인하였으며, 그들의 열적 상전이 온도 및 안정성들은 시차주사 열량분석기와 편광현미경으로 조사하였다.

Keywords

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) https://doi.org/10.1021/ma00180a015
  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) https://doi.org/10.1021/ma00005a019
  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) https://doi.org/10.1002/pola.1993.080310517
  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', Eur. Polym. J., 36, 1183 (2000) https://doi.org/10.1016/S0014-3057(99)00164-0
  10. K. limura, N. Koide, H. Tanabe, and M. Takeda, 'Syntheses of Thermotropic Liquid Crystalline Polymers', Makrmol. Chem., 182, 2569 (1981) https://doi.org/10.1002/macp.1981.021821005
  11. M. Tanaka and T. Nakaya, 'Liquid crystalline Polyurethanes', Makromol. Chem., 187, 2345 (1986) https://doi.org/10.1002/macp.1986.021871005
  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) https://doi.org/10.1021/ma00071a001
  14. J. B. Lee, T. Kato, S. Ujiie, K. limura, 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 Mat. Sci., 35, 279 (2000) https://doi.org/10.1023/A:1004728814128
  17. J. B. Lee, 'Thermal Properties of Liquid-Crystalline Polyurethanes Containing Biphenylene Mesogenic Unit', J. Ind Eng. Chem., 6, 338 (2000) https://doi.org/10.1021/ie50064a028
  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 Msogen Containing 4,4' -bis($\omega$-hydroxyalkoxy)biphenyls', J. Korean Ind Eng. Chem, 13, 654 (2002)