Liquid Crystalline Thermoset Films Based on Wholly Aromatic Copolymers

전방향족 공중합체의 열경화성 액정필름

  • Moon, Hyun-Gon (Department of Polymer Sdence and Engineerjng, Kllmoh Nationallnstitllte of Technology) ;
  • Ahn, Yong-Ho (Department of Phsics, Korea Advanced Institute of Science and Technology) ;
  • Chang, Jin-Hae (Department of Polymer Sdence and Engineerjng, Kllmoh Nationallnstitllte of Technology)
  • 문현곤 (금오공과대학교 고분자공학과) ;
  • 안용호 (한국과학기술원 물리학과) ;
  • 장진해 (금오공과대학교 고분자공학과)
  • Received : 2010.03.07
  • Accepted : 2010.04.13
  • Published : 2010.07.25

Abstract

We used melt polymerization method to prepare a series of aromatic liquid crystals (LCs) based on aromatic ester and amide units with the reactive methyl-maleimide end group, and then the resulting thermally cross-linked LCs to produce LC thermoset films by means of solution casting and the followed heat treatment. The synthesized LCs and LCTs were characterized by Fourier transform infrared (FTIR) spectroscopy, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), thermomechanical analysis (TMA), X-ray diffractometry (XRD), and polarizing optical microscopy (POM) with a hot stage. All of the LCs prepared by melt polymerization method formed smectic mesophases. The thermal properties of the LC and LCT films were strongly affected by the mesogen units in the main chain structures. The thermal expansion coefficients of samples were in the range of 27.72~50.95 ppm/$^{\circ}C$.

용융 중합법을 이용하여 말단에 메틸 말레이미드(methyl maleimide) 반응성기를 가지며 방향족 에스터와 아 미드 결합을 포함하는 액정(liquid crystal, LC)을 합성하였다. 합성된 액정은 용액 캐스팅과 열처리를 거쳐 열경화 성 액정(liquid crystalline thermoset, LCT) 필름으로 제조되었다. 합성된 LC 및 LCT는 적외선 분광기(FTIR), 시차주사 열량계(DSC), 열중량 분석기(TGA), 열-기계 분석기(TMA), X-선 회절기(XRD) 및 가열판이 부착된 편광 현미경(POM) 등을 이용해서 각각 특성 분석을 하였다. 합성된 모든 액정은 스멕틱(smectic) 상을 보였으며 LC와 LCT들의 열적 성질은 주로 주사슬에 포함된 메소젠 구조에 영향을 받았다. 열팽창 계수(coefficients of thermal expansion, CTE)는 27.72~50.95 ppm/$^{\circ}C$ 사이의 값을 보였다.

Keywords

References

  1. S. L. Wunder and S. Ramachandran, Macromolecules, 19, 1969 (1986).
  2. W. J. Jackson, Jr., Polym. J., 212, 154 (1980).
  3. J.-I. Jin, J.-H. Chang, and H. K. Shim, Macromolecules, 19, 1969 (1986).
  4. J.-I. Jin and J.-H. Chang, Macromolecules, 22, 4402 (1989). https://doi.org/10.1021/ma00202a002
  5. T. Heitz, P. Rohrbach, and H. Hocker, Macromol. Chem., 190, 3295 (1985).
  6. J.-I. Jin and C. S. Kang, Prog. Polym. Sci., 22, 937 (1997). https://doi.org/10.1016/S0079-6700(97)00013-0
  7. D. Lincoln and E. Douglas, Polym. Eng. Sci., 39, 1903 (1999). https://doi.org/10.1002/pen.11583
  8. A. P. Melissaris and M. H. Litt, Macromolecules, 27, 2675 (1994). https://doi.org/10.1021/ma00088a005
  9. M. H. Litt, W. T. Whang, K. T. Yen, and X. J. Quin, J. Polym. Sci. Part A: Polym. Chem., 31, 183 (1993). https://doi.org/10.1002/pola.1993.080310122
  10. R. A. M. Hikmet and D. J. Broer, Polymer. 32, 1627 (1991). https://doi.org/10.1016/0032-3861(91)90398-3
  11. D. A. Langlois, B. C. Benicewicz, and E. P. Douglas. Chem. Mater., 10, 3393 (1998). https://doi.org/10.1021/cm980087b
  12. A. J. Gavrin and E. P. Douglas, Macromolecules, 34, 5876 (2001). https://doi.org/10.1021/ma001884+
  13. C. Carfagna, E. Amendola, and M. Giamberini, Compo. Struc., 27, 37 (1994) https://doi.org/10.1016/0263-8223(94)90064-7
  14. B. S. Rao, J. Polym. Sci. Part C: Polym. Lett., 26, 3 (1988). https://doi.org/10.1002/pol.1988.140260101
  15. A. E. Hoyt and B. C. Benicewicz, J. Polym. Sci. Part A: Polym. Chem., 28, 3403 (1990). https://doi.org/10.1002/pola.1990.080281218
  16. A. E. Hoyt and B. C. Benicewicz, J. Polym. Sci. Part A : Polym. Chem., 28, 3417 (1990) https://doi.org/10.1002/pola.1990.080281219
  17. H. Komer, A. Shiota, C. K. Ober, and M. Laus, Chem. Mater., 9, 1588 (1997). https://doi.org/10.1021/cm960642e
  18. W. Mormann and J. G. Zimmermann, Macromolecules, 29, 1105 (1996). https://doi.org/10.1021/ma950435k
  19. Z. D. Wang and S. Q. Jiang, Trans. Nonferrous Met. Soc. China, 16, 220 (2006). https://doi.org/10.1016/S1003-6326(06)60179-9
  20. H. Masatoshi and T. Azumi, J. Photopolym. Sci. Tech., 18. 307 (2005). https://doi.org/10.2494/photopolymer.18.307
  21. H. Masatoshi, T. Yuma, K. Kazunori, and T. Azumi, J. Photopolym. Sci. Tech., 19, 285 (2006). https://doi.org/10.2494/photopolymer.19.285
  22. D. A. Langlois, B. C. Benicewicz, and E. P. Douglas, Chem. Mater., 6, 1925 (1994). https://doi.org/10.1021/cm00047a007
  23. W.-F. A. Su, J. Polym. Sci. Part A: Polym. Chem., 31, 3251 (1993). https://doi.org/10.1002/pola.1993.080311312
  24. A. Shiota and C. K. Ober, Prog. Polym. Sci., 22, 975 (1997). https://doi.org/10.1016/S0079-6700(97)00014-2
  25. P. Gilli. V. Bertolasi, V. Ferretti, and G. Gilli, J. Am, Chem. Soc., 122, 10405 (2000). https://doi.org/10.1021/ja000921+
  26. Y. I. Tien and K. H. Wei, Polymer. 42, 3213 (2001). https://doi.org/10.1016/S0032-3861(00)00729-1
  27. G. G. Barclay and C. K. Ober, Prog. Polym. Sci., 18, 899 (1993) . https://doi.org/10.1016/0079-6700(93)90021-4
  28. Y.-H. Ahn, M.-S. Jung, and J.-H. Chang, Mater. Chem. Phys., in press.
  29. A. J. Gavrin, C. L. Curts, and E. P. Douglas, J. Polym. Sci. Part A: Polym. Chem., 37, 4184 (1999) https://doi.org/10.1002/(SICI)1099-0518(19991115)37:22<4184::AID-POLA18>3.0.CO;2-Q
  30. L. Jin, T. Agag, and H. Ishida, Eur. Polym. J., 46, 354 (2010). https://doi.org/10.1016/j.eurpolymj.2009.09.013