폴리[1-{4-{4'-시아노페닐아조)펜옥시알킬옥시}에틸렌]들의 열방성 액정 거동

Thermotropic Liquid Crystalline Behavior of Poly[1-{4-(4'-cyanophenylazo)phenoxyalkyloxy}ethylene]s

  • 정승용 (단국대학교 고분자공학과) ;
  • 이재윤 (단국대학교 고분자공학과) ;
  • 마영대 (단국대학교 고분자공학과)
  • Jeong, Seung-Yong (Department of Polymer Science and Engineering, Dankook University) ;
  • Lee, Jae-Yoon (Department of Polymer Science and Engineering, Dankook University) ;
  • Ma, Yung-Dae (Department of Polymer Science and Engineering, Dankook University)
  • 발행 : 2009.07.25

초록

폴리(비닐 알코올)과 1-{4-(4'-시아노페닐아조)펜옥시}알킬브롬들(CAFBn, n=$2{\sim}10$)을 이용하여 곁사슬형 액정 동족체들인 폴리 [1-(4-(4'-시아노페닐아조)펜옥시알킬옥시)에틸렌]들(CAFETn, n=$2{\sim}10$, 유연격자중의 메틸렌 단위들의 수)을 합성함과 동시에 이들의 열방성 액정 특성을 검토하였다. n=$2{\sim}5$인 CAPBn은 액정 상들을 형성하지 않는 반면 CAPB6 그리고 n=$7{\sim}10$인 CAPBn들은 각각 쌍방성 그리고 단방성 네마틱 상들을 형성 하였다. 이러한 사실과 판이하게, CAPETn 고분자들 중에서 CAPET5만이 쌍방성 네마틱 상을 형성하는 반면 나머지 고분자들은 단방성 네미틱 상들을 형성하였다. CAPETn들의 액체 상에서 네마틱 상으로의 전이온도들 그리고 CAPBn들에 비해 큰 값들을 갖는 CAPETn들의 상 전이시의 엔트로피 변화는 n의 함수로서 전형적인 홀수-짝수 효과를 나타냈다. 이러한 상 전이 거동들을 Imrie에 의한 'virtual trimer model'의 견지에서 검토하였다. CAPETn들의 액정 상의 특성들은 폴리아크릴레이트, 폴리메타크릴레이트 그리고 폴리스티렌에 (시아노페닐아조)펜옥시 그룹들을 플리메틸렌 유연격자들을 통하여 연결시켜 얻은 고분자들에 대해 보고된 결과와 크게 달랐다. 이러한 결과들은 주사슬과 곁사슬 그룹의 화학적 결합양식이 액정 상의 형성능, 안정성 그리고 구조에 중요한 역할을 함을 시사한다.

A homologous series of side chain liquid crystalline polymers, poly [1-{4-(4'-cyanophenylazo)phenoxyalkyloxy}ethylene]s(CAPETn, where n, the number of methylene units in the spacer, is $2{\sim}10$) were synthesized from poly(vinyl alcohol) and 1-{4-(4'-cyanophenylazo)phenoxy}alkylbromides(CAPBn, n=$2{\sim}10$), and their thermotropic liquid crystalline phase behaviors were investigated. The CAPBn with n of $2{\sim}5$ did not show any liquid crystalline behavior, while those with n of 6 and $7{\sim}10$ showed enantiotropic and monotropic nematic phases, respectively. In contrast, among the CAPETn polymers, only CAPET5 exhibited an enantiotropic nematic phase, while other polymers showed monotropic nematic phases. The isotropic-nematic transition temperatures of CAPETns and their entropy variation at the phase transition that were higher values than those of CAPBns, demonstrated a typical odd-even effect as a function of n. These phase transition behaviors were disscussed in terms of the 'virtual trimer model' by Imrie. The mesophase properties of CAPETns were largely different from those reported for the polymers in which the (cyanophenylazo) phenoxy groups are attached to polyacrylate, polymethacrylate, and polystyrene backbones through polymethylene spacers. The results indicate that the mode of chemical linkage of the side group with the main chain plays an important role in the formation, stabilization, and type of mesophase.

키워드

참고문헌

  1. H. Finkelmann, M. Happ, M. Portugall, and H. Ringsdorf, Makromol. Chem., 179, 2541 (1978) https://doi.org/10.1002/macp.1978.021791018
  2. V. Percee and C. Pugh, Side Chain Liquid Crystal Polymers, C. B. McArdle, Editor, Chapmann and Hall, New York, Chap. 3, p 30 (1989)
  3. V. P. Shibaev, Liquid-Crystal Polymers, N. A. Plate, Editor, Plenum Press, New York and London, Chap. 6, p 193 (1993)
  4. C. Pugh and A. L. Kiste, Handbook of Liquid Crystals, D. Demus, J. Goodby, G. W. Gray, H.-W. Spiess, and V. Vill, Editors, Wiley-VCH, Weinheim-New York, Vol 3, Chap. Ⅲ, p 123 (1998)
  5. V. Percee and D. M. Tomazos, Comprehensive Polymer Science, First Supplement, S. L. Aggarwal and R. Russo, Editors, Pergamon Press, Oxford, Chap. 14, p 229 (1992)
  6. V. Shibaev, A. Bobrovsky, and N. Boiko, Prog. Polym. Sci., 28, 729 (2003) https://doi.org/10.1016/S0079-6700(02)00086-2
  7. S. K. Tesodha, C. K. Sadashiva Pillai, and N. Tsutsumi, Prog. Polym. Sci., 29, 45 (2004) https://doi.org/10.1016/j.progpolymsci.2003.07.002
  8. S.-Y. Jeong and Y.-D. Ma, Polymer(Korea), 30, 35 (2006)
  9. S.-Y. Jeong and Y.-D. Ma, Polymer(Korea), 33, 144 (2009)
  10. S.-Y. Jeong and Y.-D. Ma, Polymer(Korea), 32, 169 (2008)
  11. S.-Y. Jeong and Y.-D. Ma, Polymer(Korea), 32, 489 (2008)
  12. S.-Y. Jeong and Y.-D. Ma, Polymer(Korea), 33, 58 (2009)
  13. V. P. Shibaev and Ya. S. Fridzon, Side Chain Liquid Crystal Polymers, C. B. McArdle, Editor, Chapmann and Hall, New York, Chap. 9, p 260 (1989)
  14. H. Hattori and T. Uryu, J. Polym. Sci. Part A: Polym. Chem., 38, 337 (2000) https://doi.org/10.1002/(SICI)1099-0518(20000115)38:2<337::AID-POLA8>3.0.CO;2-3
  15. T. Kaneko, H. Nagasawa, J. P. Gong, and Y. Osada, Macromolecules, 37, 187 (2004) https://doi.org/10.1021/ma035272b
  16. T. Yamaguchi, T. Asada, H. Hayashi, and N. Nakamura, Macromolecules, 22, 1141 (1989) https://doi.org/10.1021/ma00193a024
  17. M. Li, E. Zhou, J. Xu, and X. Chen, J. Appl. Polym. Sci., 60, 2185 (1996) https://doi.org/10.1002/(SICI)1097-4628(19960620)60:12<2185::AID-APP16>3.0.CO;2-6
  18. C. T. Imrie, F. E. Karasz, and G. S. Attard, Macromolecules, 26, 545 (1993) https://doi.org/10.1021/ma00055a021
  19. T. Ikeda, J. Mater. Chem., 13, 2037 (2003) https://doi.org/10.1039/b306216n
  20. A. Natanshon and P. Rochon, Chem. Rev., 102, 4139 (2002) https://doi.org/10.1021/cr970155y
  21. K. Ichimura, Chem. Rev., 100, 1847 (2000) https://doi.org/10.1021/cr980079e
  22. J. Liu, K. Sun, Z. Li, J. Gao, W. Su, J. Yang, J. Zhang, P. Wang, and Q. Zhang, Polymer, 45, 4331 (2004) https://doi.org/10.1016/j.polymer.2004.04.003
  23. P. Forcen, L. Oriol, C. Sanchez, R. Alcala, S. Hvilsted, K. Jankova, and J. Loos, J. Polym. Sci. Part A: Polym. Chem., 45, 1899 (2007) https://doi.org/10.1002/pola.21954
  24. K. Rameshbabu and P. Kannan, J. Appl. Polym. Sci., 104, 2760 (2007) https://doi.org/10.1002/app.25926
  25. F. J. Rodriguez, C. Sanchez, B. Villacampa, R. Alcala, R. Cases, M. Millaruelo, L. Oriol, and E. Lorincz, Opt. Mater., 28, 480 (2006) https://doi.org/10.1016/j.optmat.2005.02.005
  26. M. Ratloh, J. Stumpe, L. Stachanov, S. Kostromin, and V. Shibaev, Mol. Cryst. Liq. Cryst., 352, 149 (2000) https://doi.org/10.1080/10587250008023172
  27. O. Tsutumi, T. Kitsunai, A. Kanazawa, T. Shiono, and T. Ikeda, Macromolecules, 31, 355 (1998) https://doi.org/10.1021/ma971344l
  28. N. A. Nikonorova, T. I. Borisova, and V. P. Shibaev, Macromol. Chem. Phys., 201, 226 (2000) https://doi.org/10.1002/(SICI)1521-3935(20000201)201:2<226::AID-MACP226>3.0.CO;2-M
  29. C. T. Imrie, T. Schleeh, F. E. Karasz, and G. S. Attard, Macromolecules, 26, 539 (1993) https://doi.org/10.1021/ma00055a020
  30. H. Ringsdorf and H.-W. Schmidt, Makromol. Chem., 185, 1327 (1984) https://doi.org/10.1002/macp.1984.021850706
  31. A. A. Craig, I. Winchester, P. C. Madden, P. Larcey, I. W. Hamley, and C. T. Imrie, Polymer, 39, 1197 (1998) https://doi.org/10.1016/S0032-3861(97)00394-7
  32. H.-K. Lee, A. Kanazawa, T. Schiono, T. Ikeda, T. Fujisawa, M. Aizawa, and B. Lee, J. Appl. Phys., 86, 5927 (1999) https://doi.org/10.1063/1.371717
  33. L. Andruzzi, A. Altomare, F. Ciardelli, R. Solaro, S. Hvilsted, and P. S. Ramanujam, Macromolecules, 32, 448 (1999) https://doi.org/10.1021/ma980160j
  34. J. Liu, K. Sun, Z. Li, J. Gao, W. Su, J. Yang, J. Zhang, P. Wang, and Q. Zhang, Polymer, 45, 4331 (2004) https://doi.org/10.1016/j.polymer.2004.04.003
  35. R. Rahmann, Polym. Inter., 43, 103 (1997) https://doi.org/10.1002/(SICI)1097-0126(199706)43:2<103::AID-PI706>3.0.CO;2-1
  36. M. Han, M. Kidowaki, K. Ichimura, P. S. Ramanujam, and S. Hvilsted, Macromolecules, 34, 4256 (2001) https://doi.org/10.1021/ma001640p
  37. A. Altomare, L. Andruzzi, F. Ciardelli, M. Mader, N. Tirelli, and R. Solaro, Macromol. Symp., 137, 33 (1999) https://doi.org/10.1002/masy.19991370105
  38. A. A. Craig and C. T. Imrie, Macromolecules, 32, 6215 (1999) https://doi.org/10.1021/ma990525f
  39. C. T. Imrie, F. E. Karasz, and G. S. Attard, Macromolecules, 26, 545 (1993) https://doi.org/10.1021/ma00055a021
  40. T. Takada, T. Fukuda, J. Watanabe, and T. Miyamoto, Macromolecules, 28, 3394 (1995) https://doi.org/10.1021/ma00113a045
  41. J.-W. Lee, J.-I, Jin, B.-W. Jo, J.-S. Kim, W.-C. Zin, and Y.-S. Kang, Acta Polym., 50, 399 (1999) https://doi.org/10.1002/(SICI)1521-4044(19991201)50:11/12<399::AID-APOL399>3.0.CO;2-7
  42. G. W. Gray, The Molecular Physics of Liquid Crystals, G. R. Luckhurst and G. W. Gray, Editors, Academic Press, New York, Chap. 1, p 1 (1979)
  43. S.-Y. Jeong and Y.-D. Ma, J. Korean Ind. Eng. Chem., 19, 504 (2008)
  44. P. A. Henderson, A. G. Cook, and C. T. Imrie, Liq. Cryst., 31, 1427 (2004) https://doi.org/10.1080/02678290412331298067
  45. F. Dowell and D. E. Martire, J. Chem. Phys., 68, 1094 (1979) https://doi.org/10.1063/1.435787
  46. Z. Komiya and R. R. Schrock, Macromolecules, 26, 1393 (1993) https://doi.org/10.1021/ma00058a031
  47. R. Zentel, Handbook of Liquid Crystals, D. Demus, J. Goodby, G. W. Gray, H.-W. Spiess, and V. Vill, Editors, Wiley-VCH, Weinheim-New York, Vol 3, Chap. 3, p 52 (1998)
  48. A. A. Craig and C. T. Imrie, Macromolecules, 28, 3617 (1995) https://doi.org/10.1021/ma00114a015
  49. C. T. Imrie, F. E. Karasz, and G. S. Attard, Macromolecules, 26, 3803 (1993) https://doi.org/10.1021/ma00067a013
  50. T. Imrie and G. R. Luckhurst, Handbook of Liquid Crystals, D. Demus, J. Goodby, G. W. Gray, H.-W. Spiess, and V. Vill, Editors, Wiley-VCH, Weinheim-New York, Vol 2B, Chap. Ⅹ, p 801 (1998)
  51. P. J. Collings and M. Hird, Introduction to Liquid Crystals, G. W. Gray, G. W. Goodby, and A. Fukuda, Editors, Tayler and Francis Ltd., London, Chap. 3, p 43 (1997)
  52. S.-Y. Jeong and Y.-D. Ma, Chemical Materials(Dankook University), 4, 19 (2007)
  53. E. M. Barrall Ⅱ and J. F. Johnson, Liquid Crystals and Plastic Crystals, G. W. Gray and P. A. Winsor, Editors, Ellis Harwood, Chichester, England, Vol 2, Chap. 10, p 254 (1974)
  54. A. A. Craig and C. T. Imrie, J. Mater. Chem., 4, 1705 (1994) https://doi.org/10.1039/jm9940401705
  55. E. Chiellini and M. Laus, Handbook of Liquid Crystals, D. Demus, J. Goodby, G. W. Gray, H.-W. Spiess, and V. Vill, Editors, Wiley-VCH, Weinheim-New York, Vol 3, Chap. 2, p 26 (1998)