Journal of Materials Science

, Volume 30, Issue 21, pp 5522–5530 | Cite as

Tensile dilatometry of injection-moulded HDPE/PA6 blends

  • S. Fellahi
  • B. D. Favis
  • B. Fisa


In order to understand the mechanism of deformation of injection-moulded HDPE/PA6 (25 vol% /75 vol%) blends both with and without compatibilizer, the volume change has been monitored using tensile dilatometry. Dog-bone specimens were either directly moulded or cut from rectangular plaques. Both neat materials and their blends were tested. For the directly moulded dog-bone specimen, a pure shear yielding mechanism was observed for all materials tested, i.e. PA6, HDPE, and their blends in the same proportion as above. In the case of a deformable minor phase (HDPE), the dispersed phase appeared to bear its share of stress and the flow-induced orientation mimics the effect of interfacial modification. This was not the case of a rigid minor phase (glass beads) at the same concentration; the effect of surface treatment changed the mechanism of deformation from mixed mode cavitation shear yielding (45%) to almost pure shear yielding (85%). Machined specimens made of neat PA6 and HDPE deformed through pure shear yielding. The addition of 25 vol% HDPE to PA6 resulted in a mixed mode cavitation (55%)/shear yielding mechanism of deformation in the transverse direction, while in the longitudinal case, the mechanism which prevailed was almost pure shear yielding (80%). This can be attributed to the flow-induced orientation as above. When adding 10% (based on the weight of the dispersed phase) of an ionomer as a compatibilizer, the blend deformed via shear yielding (85%) and in the longitudinal direction both compatibilized and non-compatibilized blends display similar behaviour. Varying the specimen thickness by changing the mould cavity, led to a significant variation in the dilatational behaviour. Dilatometric behaviour is shown to be closely related to the morphology generated as a result of flow-induced orientation. The skin/core ratio, which is an indication of the proportion of the oriented dispersed phase to the non-oriented one, plays a key role in influencing the mechanism of deformation involved.


Cavitation Disperse Phase Minor Phase HDPE Dilatometry 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    B. D. Favis, Can. J. Chem. Eng. 69 (1991) 619.CrossRefGoogle Scholar
  2. 2.
    L. A. Utracki, “Polymer blends and alloys: thermodynamics and rheology” (Hanser, Munich, 1989).Google Scholar
  3. 3.
    A. Plochocki, in “Polymer blends”, Vol. 1, edited by D. R. Paul and S. Newman (Academic Press, New York, 1978) Ch. 21, p. 319.CrossRefGoogle Scholar
  4. 4.
    T. M. Liu, H. Q. Xie, A. O'Callaghan, A. Rudinand W. E. Baker, J. Polym. Sci. B Polym. Phys. 31 (1993) 1347.CrossRefGoogle Scholar
  5. 5.
    B. Fisa and M. Rahmani, Polym. Eng. Sci. 31 (1991) 1330.CrossRefGoogle Scholar
  6. 6.
    B. Fisa and A. Meddad, ibid., in press.CrossRefGoogle Scholar
  7. 7.
    J. W. Coumans, D. Heikens and S. D. Sjoerdsma, Polymer 21 (1980) 103.CrossRefGoogle Scholar
  8. 8.
    M. E. J. Dekkers and D. Heikens, J. Appl. Polym. Sci. 30 (1985) 2389.CrossRefGoogle Scholar
  9. 9.
    R. W. Truss and G. A. Chadwick, J. Mater. Sci. 11 (1976) 111.CrossRefGoogle Scholar
  10. 10.
    L. G. Cessna, Polym. Eng. Sci. 14 (1974) 696.CrossRefGoogle Scholar
  11. 11.
    M. C. Schwarz, H. Keskulla, J. W. Barlow and D. R. Paul, J. Appl. Polym. Sci. 35 (1988) 653.CrossRefGoogle Scholar
  12. 12.
    C. B. Bucknall and D. Clayton, Nature 231 (1971) 107.CrossRefGoogle Scholar
  13. 13.
    R. J. M. Borggreve, R. J. Gaymans and H. M. Eichenwald, Polymer 30 (1989) 79.Google Scholar
  14. 14.
    D. S. Parker, H. J. Sue and A. F. Yee, ibid. 31 (1990) 2267.CrossRefGoogle Scholar
  15. 15.
    M. A. Maxwell, A. F. Yee, Polym. Eng. Sci. 21 (1981) 205.CrossRefGoogle Scholar
  16. 16.
    S. I. Naqui and I. M. Robinson, J. Mater. Sci. 28 (1993) 1421.CrossRefGoogle Scholar
  17. 17.
    S. Y. Hobbs and M. E. J. Dekkers, ibid. 24 (1989) 1316.CrossRefGoogle Scholar
  18. 18.
    I. T. Barrie, D. R. Moore and S. Turner, Plast. Rubb. Proc. Appl. 3 (1983) 365.Google Scholar
  19. 19.
    J. M. Powers and R. M. Caddel, Polym. Eng. Sci. 12 (1972) 432.CrossRefGoogle Scholar
  20. 20.
    D. C. Leach and D. R. Moore, Composites 16 (1985) 113.CrossRefGoogle Scholar
  21. 21.
    S. Y. Hobbs, M. E. J. Dekkers and V. H. Watkinson, J. Mater. Sci. 23 (1988) 1219.CrossRefGoogle Scholar
  22. 22.
    C. B. Bucknall and D. Clayton, ibid. 7 (1972) 202.CrossRefGoogle Scholar
  23. 23.
    A. F. Yee and R. A. Pearson, ibid. 21 (1986) 2462.CrossRefGoogle Scholar
  24. 24.
    E. A. A. van Hartigsveldt, PhD. thesis, University of Delft Holland (1987).Google Scholar
  25. 25.
    H. Bertilson, B. Franzen and J. Kubat, Plast. Rubb. Process. Appl. (1991).Google Scholar
  26. 26.
    S. Fellahi, B. D. Favis and B. Fisa, SPE Antec Tech. Papers 39 (1993) 211.Google Scholar
  27. 27.
    Idem, Polymer, in press.Google Scholar
  28. 28.
    A. Meddad, S. Fellahi, M. Pinard and B. Fisa, SPE Antec Tech. Papers 40 (1994) 2284.Google Scholar
  29. 29.
    R. Armat and A. Moet, Polymer 34 (1993) 977.CrossRefGoogle Scholar
  30. 30.
    D. W. Bartlett, J. W. Barlow and D. R. Paul, J. Appl. Polym. Sci. 27 (1982) 235.CrossRefGoogle Scholar
  31. 31.
    G. Menges, A. Troost, J. Koske, H. Ries and H. Stabrey, Kunstst. Germ. Plast. 78 (1988) 22.Google Scholar

Copyright information

© Chapman & Hall 1995

Authors and Affiliations

  • S. Fellahi
    • 1
  • B. D. Favis
    • 1
  • B. Fisa
    • 1
  1. 1.Centre de recherche appliquée sur les polymères(CRASP)Ecole Polytechnique de MontréalMontréalCanada

Personalised recommendations