Journal of Materials Science

, Volume 34, Issue 18, pp 4489–4500 | Cite as

Effect of crystalline phase, orientation and temperature on the dielectric properties of poly (vinylidene fluoride) (PVDF)



The effect of crystalline phase, uniaxial drawing and temperature on the real (ε′) and imaginary (ε″) parts of the relative complex permittivity of poly (vinylidene fluoride) (PVDF) was studied in the frequency range between 102 and 106 Hz. Samples containing predominantly α and β phases, or a mixture of these, were obtained by crystallization from a DMF solution at different temperatures. α phase samples were also obtained from melt crystallization and from commercial films supplied by Bemberg Folien. Different molecular orientations were obtained by uniaxial drawing of α and β phase samples. The results showed that the crystalline phase exerts strong influence on the values of ε′ and ε″, indicating that the αa relaxation process, associated with the glass transition of PVDF, is not exclsively related to the amorphous region of the polymer. An interphase region, which maintains the conformational characteristics of the crystalline regions, should influence the process decisively. The molecular orientation increased the values of ε′ for both PVDF phases and modified its dependence with temperature over the whole frequency range studied. The influence of the crystallization and molecular orientation conditions on the dc electric conductivity (σdc) were also verified. The value of σdc was slightly higher for samples crystallized from solution at the lowest temperature and decreased with draw ratio.


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  1. 1.
    K. Kobayashi and T. Yamada, Ferroelectrics 32 (1981) 181.Google Scholar
  2. 2.
    A. Dereggi, ibid. 60 (1984) 83.Google Scholar
  3. 3.
    T. T. Wang, J. M. Herbert and A. M. Glass, “The Applications of Ferroelectric Polymers” (Chapman and Hall, New York, 1988).Google Scholar
  4. 4.
    S. Hurmila, H. Stubb, J. Pitkanen, K. Lahdenpera and A. Penttinen, Ferroelectrics 115 (1991) 267.Google Scholar
  5. 5.
    H. Meixner, ibid. 115 (1991) 279.Google Scholar
  6. 6.
    Q. X. Chen and P. A. Payne, Meas. Sci. Techonol. 6 (1995) 249.Google Scholar
  7. 7.
    R. Gregorio, JR. and M. Cestari, J. Polym. Sci.:B: Polym. Phys. 32 (1994) 857.Google Scholar
  8. 8.
    T. C. Hsu and P. H. Geil, J. Mater. Sci. 24 (1989) 1219.Google Scholar
  9. 9.
    J. C. Magrath and I. M. Ward, Polymer 21 (1980) 855.Google Scholar
  10. 10.
    R. Gregorio, JR., R. Cestari, N. C. P. S. Nociti, J. A. MendonÇa and A. A. Lucas, “The Polymeric Materials Encyclupedia: Synthesis, Properties and Applications” (CRC Press, USA, 1996) p. 2286.Google Scholar
  11. 11.
    R. Gregorio, JR. and J. A. MendonÇa, in Proceedings of the 2nd Brazilian Polymer Congress, São Paulo, Brazil, October 1993, p. 535 (in Portuguese).Google Scholar
  12. 12.
    H. Sasabe, S. Saito, M. Asahina and H. Kakutani, J. Polym. Sci. A2(7) (1969) 1405.Google Scholar
  13. 13.
    S. J. Yano, Polym. Sci. A2(8) (1970) 1057.Google Scholar
  14. 14.
    K. Nakagawa and Y. Ishida, J. Polym. Sci: Polym. Phys. Ed. 11 (1973) 1503.Google Scholar
  15. 15.
    V. J. Mcbrierty, D.C. Douglass and T. A. Werber, ibid. 14 (1976) 1271.Google Scholar
  16. 16.
    B. Hahn, J. Wendorff and D. Y. Yoon, Macromol. 18 (1985) 718.Google Scholar
  17. 17.
    Y. Ando, T. Hanada and K. saitoh, J. Poly. Sci.:B:Poly. Phys. 32 (1994) 179.Google Scholar
  18. 18.
    T. FurukawÀ, M. Ohuchi, A. Chiba and M. Date, Macromol. 17 (1984) 1384.Google Scholar
  19. 19.
    H. J. Kestenbach, R. Gregorio, JR., J. Loos and J. Petermann, Polímeros: Ciêcia e Tecnologia 1 (January/ March, 1997) 58 ( in Portuguese).Google Scholar
  20. 20.
    N. F. Mott and R. W. Gurney, “Electroinc Processes in Ionic Crystals” ( Oxford University Press, London, 1940) p. 43.Google Scholar
  21. 21.
    R. Gregorio, JR and M. Cestari, in Proceedings of the. X CBECIMAT, Águas de Lindóia-SP, Brazil, December 1992, p. 262 (in Portuguese).Google Scholar

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© Kluwer Academic Publishers 1999

Authors and Affiliations

  1. 1.Department of Materials EngineeringFederal University of São CarlosSão Carlos, São PauloBrazil
  2. 2.Department of Materials EngineeringState University of Ponta Grossa, CEPPonta Grossa-ParanáBrazil

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