Journal of Materials Science

, Volume 26, Issue 16, pp 4281–4284 | Cite as

Characterization of molecular orientation by differential scanning calorimetry

Part 1 Tg-TLL region for amorphous polymers
  • M. G. Rogers


Differential scanning calorimetry was used to study relaxations occurring above the glass transition, Tg for a number of characterized and fabricated polystyrenes. Part 1 of this study examines the liquid-liquid relaxation temperature, TLL; Part 2 the effects of injection moulding and biaxial orientation of polystyrene; and Part 3 deals with the effects of injection blow moulding.

The rubbery plateau region was found to be bounded by the glass transition, Tg, and a weak transition or relaxation, TLL, found above Tg as an endothermic slope change in the base line. In some cases, this transition could be enhanced as a step change when molten samples were quenched in liquid nitrogen.

The effect of molecular weight on Tg and TLL was similar, and had the relationships TLL/Tg=1.07+0.03 forMinw/Mn ≃1, and TLL/Tg=1.15 ± 0.01 for ¯MwMn > 1.


Differential Scanning Calorimetry Polystyrene Glass Transition Calorimetry Base Line 
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  1. 1.
    R. F. Boyer, J. Polym. Sci. B14 (1966) 267.Google Scholar
  2. 2.
    S. J. Stadnicki, J. K. Gillham and R. F. Boyer, J. Appl. Polym. Sci. B20 (1976) 1245.CrossRefGoogle Scholar
  3. 3.
    J. B. Enns, R. F. Boyer and J. K. Gillham, Polym. Prepr., Amer. Chem. Soc. B18 (1977) 475.Google Scholar
  4. 4.
    C. A. Glandt, H. K. Toh, J. K. Gillham and R. F. Boyer, J. Appl. Polym. Sci. B20 (1976) 1277.CrossRefGoogle Scholar
  5. 5.
    J. K. Gillham, J. A. Benci and R. F. Boyer, Polym. Engng Sci B16 (1976) 357.CrossRefGoogle Scholar
  6. 6.
    Idem, ibid. B16 (1976) 357.CrossRefGoogle Scholar
  7. 7.
    R. F. Boyer, J. Appl. Polym. Sci. B33 (1987) 955.CrossRefGoogle Scholar
  8. 8.
    J. K. Gillham and R. F. Boyer in “Thermal Methods in Polymer Analysis” edited by S. W. Shalaby (Franklin Inst. Press, Philadelphia, Pennsylvania, 1978) p. 5.Google Scholar
  9. 9.
    E. A. Sidorovich, A. I. Marci and N. S. Gashtoe'd, Rubber Chem. Tech. B44 (1971) 166.CrossRefGoogle Scholar
  10. 10.
    J. K. Gillham, AICHE J. B20 (1974) 1066.CrossRefGoogle Scholar
  11. 11.
    C. A. Glandt, H. K. Toh, J. K. Gillham and R. F. Boyer, J. Appl. Polym. Sci B20 (1976) 1277, 2009.CrossRefGoogle Scholar
  12. 12.
    J. K. Gillham, Polym Engng Sci. B19 (1979) 749.CrossRefGoogle Scholar
  13. 13.
    L. E. Nielsen, ibid. B17 (1977) 413.Google Scholar
  14. 14.
    J. Chen, C. Kow, L. J. Fetters and D. J. Plasek, J. Polym. Sci. Polym. Phys. Edn B20 (1982) 1565.CrossRefGoogle Scholar
  15. 15.
    R. F. Boyer, ibid. B23 (1985) 1.Google Scholar
  16. 16.
    S. W. Shalaby in “Thermal Characterization of Polymer Materials” edited by E. A. Turi (Academic Press, London, 1981) p. 337.Google Scholar
  17. 17.
    R. F. Boyer in “Polymer Yearbook 2” edited by R. A. Pethrick (Harwood Academic, 1985) p. 233.Google Scholar
  18. 18.
    T. G. Fox and P. J. Flury, J. Polym. J. B14 (1954) 315.Google Scholar
  19. 19.
    L. R. Denny, R. F. Boyer and H. G. Elias, J. Macromolec. Sci Phys. B25 (1986) 277.Google Scholar
  20. 20.
    S. S. Chang, Polym. Commun. 29 (1988) 33.Google Scholar
  21. 21.
    E. Janckel and V. Ueberreiter, Z. Physik. Chemie BA182 (1938) 361.Google Scholar
  22. 22.
    T. G. Fox and P. J. Flury, J. Appl. Phys. B21 (1950) 581.CrossRefGoogle Scholar
  23. 23.
    J. M. G. Cowie, Engng Polym. J. B11 (1975) 297.Google Scholar
  24. 24.
    R. V. Kokta, J. L. Valade, V. Hornof and K. N. Law, in Proceedings of the fifth meeting of the North N. Americal Thermal Analysis Society, Canada, June 1975.Google Scholar
  25. 25.
    M. G. Rogers, J. Mater. Sci. 26 (1991) 335–340.CrossRefGoogle Scholar
  26. 26.
    Idem, ibid. 26 (1991) 4285.CrossRefGoogle Scholar

Copyright information

© Chapman & Hall 1991

Authors and Affiliations

  • M. G. Rogers
    • 1
  1. 1.Research and DevelopmentDow Chemical Canada Inc.SarniaCanada

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