Journal of Materials Science

, Volume 35, Issue 20, pp 5215–5223 | Cite as

Phase structures, transition behavior and surface alignment in polymers containing rigid-rod backbones with flexible side chains Part VI Novel band structures in a combined main-chain/side-chain liquid crystalline polyester: From liquid crystal to crystalline states

  • J. J. Ge
  • J. Z. Zhang
  • Wensheng Zhou
  • C. Y. Li
  • Shi Jin
  • B. H. Calhoun
  • Shy-Yeu Wang
  • F. W. Harris
  • S. Z. D. Cheng
Article

Abstract

Physical origins of banded structures appearing on different length scales have been investigated using polarized light and atomic force microscopies (PLM and AFM), polarized Fourier Transform infrared spectroscopy (FT-IR) and wide angle X-ray diffraction (WAXD) in a combined main-chain/side-chain liquid crystalline (LC) polyester, PEFBP(n). This series of PEFBP(n) polymers was synthesized from the polycondensation of 2,2′-bis(trifluoromethyl)-4,4′-biphenyldicarbonyl chloride with 2,2′-bis{ω-[4-(4-cyanophenyl)-phenyoxy]-n-alkoxycarbonyl]}-4,4′-biphenyl diol. In this paper, we focus on one polymer [PEFBP(n = 11)] of this series to illustrate the band structural formation on different length scales during the evolution from liquid crystal to crystalline states. Alternating bands of the films mechanically-sheared at 190 °C are formed with a spacing of 3 ± 0.5 μm in PLM, and recognized to be primary bands. PLM and AFM results show that these bands are seen due to the change of optical birefringence constructed mainly by alternating film thickness (and thus, retardation). Based on polarized FT-IR results, both the backbones and side chains of the polymers are orientated parallel to the shear direction. Secondary fibrillar bands develop within the primary bands after the sample is subsequently crystallized at 105 °C. These bands show a zigzag arrangement and possess a lateral size of 250 ± 50 nm determined by AFM. High resolution AFM observations illustrate that these bands consist of aggregated edge-on crystal lamellae having a thickness of approximately 20 nm. The lamellar crystals are assembled together and lie across the film thickness direction. The mechanism for the formation of these secondary zigzag bands originates from the expansion of the lattice dimension along the chain direction on a molecular scale during the nematic to crystalline phase transition and crystallization in the partially confined LC primary bands, which form macroscopic zigzag buckling.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. 1.
    K. Kerkam, C. Viney, D. L. Kaplan and S. J. Lombadrdi,Nature 349 (1991) 596.Google Scholar
  2. 2.
    M. G. Dobb, D. J. Johnson and B. P. Saville,J. Polym. Sci. Phys. 15 (1977) 2201.Google Scholar
  3. 3.
    G. Kiss and R. S. Porter,Mol. Cryst. Liq. Cryst. 60 (1980) 267.Google Scholar
  4. 4.
    T. Takebe, T. Hashimoto, B. Ernst, P. Navard and R. S. Stein,J. Chem. Phys. 92 (1990) 1386.Google Scholar
  5. 5.
    B. E. Ernest and P. Navard,Macromolecules 22 (1989) 1419.Google Scholar
  6. 6.
    S. C. Simmens and J. W. S. Hearle,J. Polym. Sci. Phys. 18 (1980) 871.Google Scholar
  7. 7.
    C. Viney, A. M. Donald and A. H. Windle,J. Mater. Sci. 18 (1983) 1136.Google Scholar
  8. 8.
    A. M. DONALD and A. H. WINDLE Idem.},Polymer 24 (1983) 155.Google Scholar
  9. 9.
    M. Hoff, A. Keller, J. A. Odell and V. Percec,Mol. Cryst. Liq. Cryst 241 (1994) 221.Google Scholar
  10. 10.
    A. KELLER, J. A. ODELL and V. PERCEC Idem.},Polymer 34 (1993) 1800.Google Scholar
  11. 11.
    M. Hoff, A. Keller and A. H. Windle,J. Non-Newtonian Fluid Mech. 67 (1996) 241.Google Scholar
  12. 12.
    C. Viney and W. Putnam,Polymer 36 (1995) 1731.Google Scholar
  13. 13.
    C. Viney and A. H. Windle,J. Mater. Sci. 18 (1983) 1143.Google Scholar
  14. 14.
    C. Viney, A. M. Donald and A. H. Windle,Polymer 26 (1985) 870.Google Scholar
  15. 15.
    S. E. Bedford and A. H. Windle,ibid. 31 (1990) 616.Google Scholar
  16. 16.
    Macromol K. Shimamura,Chem. Rapid. Commun. 4 (1983) 107.Google Scholar
  17. 17.
    C. Viney and A. H. Windle,Polymer 27 (1986) 1325.Google Scholar
  18. 18.
    S. N. Magonov and D. H. Reneker,Annu. Rev. Mater. Sci. 27 (1997) 175.Google Scholar
  19. 19.
    H. Fisher, M. Miles and J. A. Odell,Macromol. Rapid. Commun. 15 (1994) 815.Google Scholar
  20. 20.
    S.-Y. Wang, Ph.D. dissertation, Department of Polymer Science, Akron, Ohio 44325-3909, 1995.Google Scholar
  21. 21.
    J. J. Ge, A. Zhang, K. W. Mccreight, R.-M. Ho, S.-Y. Wang, X. Jin, F. W. Harris and S. Z. D. Cheng,Macromolecules 30 (1997) 6498.Google Scholar
  22. 22.
    J. J. Ge, A. Zhang, K. W. Mccreight, S.-Y. Wang, F. W. Harris and S. Z. D. Cheng,ibid. 31 (1998) 4093.Google Scholar
  23. 23.
    J. J. Ge, P. S. Honigfort, R.-M. Ho, S.-Y. Wang, F. W. Harris and S. Z. D. Cheng,Macromol. Chem. Phys. 200 (1999) 31.Google Scholar
  24. 24.
    T. Seki, M. Sakuragi, Y. Kawanishi, Y. Suzuki, T. Tamaki, R. Fukuda and K. Ichimura,Langmuir 9 (1993) 211.Google Scholar
  25. 25.
    C. S. Kang, H. J. Winklehahn, M. Schulz, D. Neher and G. Wegner,Chem. Mater. 6 (1994) 2159.Google Scholar
  26. 26.
    J. J. Ge, G. Xue, F. Li, K. W. Mccreight, S.-Y. Wang, F. W. Harris, S. Z. D. Cheng, X. Zhuang, S.-C. Hong and Y. R. Shen,Macromol. Rapid Commun. 19 (1998) 619.Google Scholar
  27. 27.
    O. Herrmann-schonherr, J. H. Wendorff, H. Ringsdorf, P. Tschirner,ibid. 7 (1986) 791.Google Scholar
  28. 28.
    M. Ballauff and G. F. Schmidt,ibid. 8 (1987) 93.Google Scholar
  29. 29.
    A. Adam and W. Spiess,ibid. 11 (1990) 249.Google Scholar
  30. 30.
    H. R. Kricheldorf and A. Domschke,Macromolecules 29 (1996) 1337.Google Scholar
  31. 31.
    G. Scrates, “Infrared Characteristics Group Frequencies” (John Wiley & Sons: Chichester, UK, 1980).Google Scholar
  32. 32.
    J. J. Ge, M. Guo, J. Z. Zhang, P. S. Honigfort, I. K. Mann, S.-Y. Wang, F. W. Harris and S. Z. D. Cheng,Macromolecules 33 (2000) 3983.Google Scholar
  33. 33.
    Y. Yoon, A. Zhang, R.-M. Ho, S. Z. D. Cheng, V. Percec and P. Chu,ibid. 29 (1996) 294.Google Scholar
  34. 34.
    J. C. Wittmann and P. Smith,Nature 352 (1990) 414.Google Scholar
  35. 35.
    P. Damman, M. Dosiere, P. Smith and J. C. Wittmann,J. Am. Chem. Soc. 117 (1995) 1120.Google Scholar
  36. 36.
    P. Damman, M. Dosire, M. Brunel and J. C. Wittmann,ibid. 119 (1997) 4333.Google Scholar

Copyright information

© Kluwer Academic Publishers 2000

Authors and Affiliations

  • J. J. Ge
    • 1
  • J. Z. Zhang
    • 1
  • Wensheng Zhou
    • 1
  • C. Y. Li
    • 1
  • Shi Jin
    • 1
  • B. H. Calhoun
    • 1
  • Shy-Yeu Wang
    • 1
  • F. W. Harris
    • 1
  • S. Z. D. Cheng
    • 2
  1. 1.The Maurice Morton Institute and Department of Polymer ScienceThe University of AkronAkronUSA
  2. 2.The Maurice Morton Institute and Department of Polymer ScienceThe University of AkronAkronUSA

Personalised recommendations