Journal of Materials Science

, Volume 15, Issue 12, pp 2945–2949 | Cite as

Extrudate distortion studies of polystyrene using an extrusion rheometer

  • Anthony A. Collyer
  • Geoffrey H. France
Papers

Abstract

Uncorrected and corrected logarithmic flow-curves for a general purpose polystyrene (MW=261000 and MW/MN=4.4) obtained using a Davenport Extrusion Rheometer are shown for the range 160 to 200° C. The uncorrected flow curves show a change in slope, but at the lower extrusion temperatures this change occurs after the appearance of distorted extrudates. The onset of extrudate distortion obtained from observation does not coincide with the change in slope of the graph. The corrected logarithmic flow curves show no change in slope. Values of \(\dot \gamma _c\) and ηc from both sets of graphs show that \(\dot \gamma _c\) is inversely proportional to ηc, and for the higher melt temperatures the corrected τc values increase with temperature. The high value of critical wall stress at 160° C is attributed to the increase in melt elasticity with decreasing temperature being a greater effect than the decrease in elasticity due to a decrease in \(\dot \gamma _c\).

Keywords

Polymer Polystyrene General Purpose Flow Curve Wall Stress 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. 1.
    J. P. Tordella, J. Appl. Phys. 27 (1956) 454.Google Scholar
  2. 2.
    E. B. Bagley, J. Appl. Phys. 28 (1957) 624.Google Scholar
  3. 3.
    H. Schott and W. S. Kaghan, Ind. Eng. Chem. 51 (1959) 844.Google Scholar
  4. 4.
    A. B. Metzner, E. L. Carley and I. K. Park, Mod. Plast. 37 (1960) 133.Google Scholar
  5. 5.
    J. P. Tordella, J. Appl. Polym. Sci. 7 (1963) 215.Google Scholar
  6. 6.
    S. Y. Choi and N. Nakajima, Proceedings of the Fifth International Conference on Rheology, 4, edited by S. Onogi (University Park Press, University Park, PA, 1970) 287.Google Scholar
  7. 7.
    R. C. Penwell and R. S. Porter, J. Polym. Sci. A-2 (1971) 463.Google Scholar
  8. 8.
    N. Nakajima and E. A. Collins, J. Appl. Polym. Sci. 22 (1978) 2435.Google Scholar
  9. 9.
    J. L. Den Otter, Plast. Polym. 38 (1970) 155.Google Scholar
  10. 10.
    Idem, Rheol. Acta 10 (1971) 200.Google Scholar
  11. 11.
    O. Bartos, J. Appl. Phys. 35 (1964) 2767.Google Scholar
  12. 12.
    P. L. Clegg, Br. Plast. 39 (1966) 96.Google Scholar
  13. 13.
    G. A. Bialas and J. L. White, Rubber Chem. Technol. 42 (1969) 675.Google Scholar
  14. 14.
    A. V. Ramamurthy, Trans. Soc. Rheol. 18 (1974) 431.Google Scholar
  15. 15.
    A. B. Metzner, Ind. Eng. Chem. 50 (1958) 1577.Google Scholar
  16. 16.
    J. P. Tordella, Trans. Soc. Rheol. 1 (1957) 203.Google Scholar
  17. 17.
    Idem, Rheol. Acta 1 (1958) 216.Google Scholar
  18. 18.
    E. R. Howells and J. J. Benbow, Trans. J. Plast. Inst. 30 (1962) 240.Google Scholar
  19. 19.
    R. F. Westover, Polym. Eng. Sci. 6 (1966) 83.Google Scholar

Copyright information

© Chapman and Hall Ltd. 1980

Authors and Affiliations

  • Anthony A. Collyer
    • 1
  • Geoffrey H. France
    • 1
  1. 1.Department of Applied PhysicsSheffield City PolytechnicSheffieldUK

Personalised recommendations