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Thermodynamic properties of high polymers as a function of their pretreatment as determined by specific heat measurements

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Summary

  1. 1.

    The absolute value of the specific heats of polyethylene, isotactic polypropylene, polyvinyl chloride, poly(tetrafluorethylene), poly(ethylene sebacate), polyethylene terephthalate), copolymers of the latter two, and 6 and 6-6 Nylon are discussed from the standpoint of the number of vibrating units per chain atom. Qualitative agreement is obtained on the assumption that each chain atom has two classical degrees of vibrational freedom.

  2. 2.

    The glass transition temperatures and the increase inc p /T at the glass transition temperature are shown to be functions of the composition of the amorphous regions, magnitude and type of crystallinity and chain orientation.T g is increased andΔ c p /T decreased by fiber orientation whileT g may be increased, decreased or unchanged by crystallization. As the concentration ofB-units in the amorphous regions of anA-B copolymer increases on crystallization,T g decreases, butΔ c p /T per mole of residual melt remains about constant. It is concluded thatT g is more conveniently determined from a cp/T versusT plot than fromH-T curves.

  3. 3.

    Crystallinity is shown to be of two types, that which is produced under equilibrium conditions,Type I crystallinity, and that which results from random crystallization in the frozen amorphous regions many degrees below the melting point,Type II or “cold” crystallinity. BothType I andType II crystallization can be observed and studied in the 80/20 copolymer of poly(ethylene terephthalate-sebacate).T g is lowered in the case ofType I crystallization, but unchanged in the case ofType II. The melting point ofType II crystals is lowered 30 or 40° from the equilibrium melting point because of the small size of the crystals produced.

  4. 4.

    Cold drawing or chain orientation produces no significant change in the heat content of the polymer provided that no changes in crystallinity occur. The observed values ofΔH for the cold drawing process are thought to be due to changes in crystallinity.

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References

  1. Smith, C. W. andM. Dole, J. Polymer Sci.20, 37 (1956).

    Google Scholar 

  2. Wunderlich, B. andM. Dole, J. Polymer Sci.24, 201 (1957).

    Google Scholar 

  3. Dole, M. andW. P. Hettinger, Jr., N. R. Larson, andJ. A. Wethington, Jr., J. Chem. Phys.20, 781 (1952).

    Google Scholar 

  4. Marx, P. andM. Dole, J. Amer. Chem. Soc.77, 4771 (1955).

    Google Scholar 

  5. Alford, S. andM. Dole, J. Amer. Chem. Soc.77, 4774 (1955).

    Google Scholar 

  6. Dole, M. andR. M. Hammaker (Unpublished).

  7. Wunderlich, B. andM. Dole, J. Polymer Sci. (In Press.).

  8. Marx, P. andC. W. Smith, A. E. Worthington andM. Dole, J. Phys. Chem.59, 1015 (1955).

    Google Scholar 

  9. Wilhoit, R. C. andM. Dole, J. Phys. Chem.57, 14 (1953).

    Google Scholar 

  10. Pitzer, K. S., J. Chem. Phys.8, 711 (1940).

    Google Scholar 

  11. Edgar, O. B., J. Chem. Soc.1952, 2638.

  12. Raff, R. A. V. andJ. B. Allison, High Polymers-Vol. XI. Polyethylene (New York 1956).

  13. Weir, C. E., J. Res. Nat'l. Bureau of Standards46, 207 (1951).

    Google Scholar 

  14. Parks, W. andR. B. Richards, Trans. Faraday Soc.45, 203 (1949).

    Google Scholar 

  15. Müller, A., Proc. Roy. Soc.178A, 227 (1941).

    Google Scholar 

  16. Stuart, H. A., Die Physik der Hochpolymeren, Bd. III (Berlin-Göttingen-Heidelberg 1955).

  17. Wunderlich, B., Doctoral Dissertation, North-western University (Evanston, Illinois 1957).

    Google Scholar 

  18. Edgar, O. B., J. Chem. Soc.1952, 2638 andE. Ellery, J. Chem. Soc.1952, 2633.

  19. Hoffman, J. D. andJ. J. Weeks (to be published).

  20. Boyer, R. F. andR. S. Spencer, J. Applied Phys.15, 398 (1944).

    Google Scholar 

  21. Ref. (16), p. 648.

  22. Flory, P. J., Trans. Faraday Soc.51, 848 (1955).

    Google Scholar 

  23. See, for example,Flory, P. J. andL. Mandel-kern, J. Polymer Sci.21, 345 (1956).

    Google Scholar 

  24. Flory, P. J., Principles of Polymer Chemistry, p. 570 (Ithaca, N.Y. 1953).

  25. Dole, M., S. Polymer Sci.19, 347 (1956).

    Google Scholar 

  26. See, for example,Epstein, P. S., Textbook of Thermodynamics (New York 1937) p. 216.

  27. Daubeny, R. deP., C. W. Bunn andC. J. Brown, Proc. Roy. Soc.A 226, 531 (1954).

    Google Scholar 

  28. Evans, R. D., H. R. Mighton andP. J. Flory, J. Am. Chem. Soc.72, 2018 (1950).

    Google Scholar 

  29. Dole, M. andB. Wunderlich, J. Polymer Sci.24, 139 (1957).

    Google Scholar 

  30. Müller, F. H. andK. Jäckel, Kolloid-Z.129, 145 (1952).

    Google Scholar 

  31. Müller, F. H. andA. Engelter, Kolloid-Z.149, 126 (1956).

    Google Scholar 

  32. Kolb, H. J. andE. F. Izard, J. Applied Phys.20, 564 (1949).

    Google Scholar 

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Authors and Affiliations

  1. Chemical Laboratory of Northwestern University, Evanston, Illinois, USA

    Malcolm Dole

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  1. Malcolm Dole
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Dole, M. Thermodynamic properties of high polymers as a function of their pretreatment as determined by specific heat measurements. Kolloid-Zeitschrift 165, 40–57 (1959). https://doi.org/10.1007/BF01797347

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  • DOI: https://doi.org/10.1007/BF01797347

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