Advertisement

Polyurethane Elastomers with Monodisperse Segments and their Model Precursors: Synthesis and Properties

  • Claus D. Eisenbach
  • Martin Baumgartner
  • Claudia Günter

Abstract

Uniform model compounds for the soft and hard segment of polyurethane (PU) elastomers and the corresponding tailormade elastomers with monodisperse segment length distribution were synthesized and characterized with the objective of getting a better understanding of the structure and morphology as well as the structure-property relationships of multiphase segmented PU elastomers from the study of such clearly defined model systems.

Monodisperse α-hydro-ω-hydroxypoly(oxytetramethylene) and hydroxy-terminated oligomers of 1,4-butanediol and 4,4’-diphenylmethanediisocyanate (soft and hard segment precursors) as well as their bis-(diphenylmethaneurethanes) (soft and hard segment model compounds) were obtained in a stepwise synthesis and in combination with chromatographic fractionation techniques, and in some cases (oligourethanes) by employing the tetrahydropyranyl protecting group. The hydroxy-terminated segment precursors were reacted to the PU elastomers with strictly mono-disperse hard segments and narrow soft segment length distribution by a modified prepolymer process which largely suppresses the pre-extension reaction; it was established that the pre-polymer formation in the melt doesn’t obey Flory statistics and that the deviations also vary with the molecular weight of the starting polyether.

The soft segment model compounds with terminal urethane groups exist in two crystalline modifications with different hydrogen bond strength between neighbouring urethane groups. Polymorphism is also observed in the case of the hydroxy-terminated hard segment precursors and is connected with deviations from the planar zig-zag conformation of the butanediol urethane part. There is no evidence for chain folding, and cocrystallization of oligourethanes of varying length only occurs between oligomers of successive length and not until a critical chain length of three repeat units is exceeded. Furthermore, the urethane group has been found to undergo a rapid transurethanization (urethane interchange) reaction already in the oligourethane melting temperature range and even without any catalyst, rendering monodisperse into polydisperse systems. Consequently, the hard segment length distribution and thus the hard domain morphology of segmented PU elastomers are affected by the thermal history in that the usual processing temperatures result in an equilibration of the segment length distribution and thus a reorganization of the hard segments.

PU elastomers with a narrow (monodisperse) hard segment length distribution show a better phase separation and higher degree of crystallinity in the hard domains as compared to elastomers with broad segment length distribution, even though the structure and morphology of the semicrystalline hard domaines is still complex and not yet fully understood. Concerning the differences in the mechanical properties between elastomers with narrow and broad segment length distributions it can be stated that monodisperse hard segments generally result in improved properties, e.g., a higher and flatter plateau modulus over a wider temperature range, and a higher softening temperature as compared to elastomers with polydisperse hard segment length distribution are characteristic for the dynamic mechanical behaviour; the soft segment length distribution has a comparatively minor effect and only the average soft segment length is of some importance in connection with the possibility of soft segment crystallization.

Keywords

High Pressure Liquid Chromatography Hard Segment Soft Segment Hard Segment Content Hard Domain 
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.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. 1).
    H. Oertel, Bayer Farben Revue, 11, 1 (1965); Chemiker Ztg., 98, 344 (1974).Google Scholar
  2. 2).
    G.M. Estes, R.W. Seymour, and S.L. Cooper, Macromolecules, 4, 452 (1971).ADSCrossRefGoogle Scholar
  3. 3).
    H. Hespe, E. Meisert, U. Eisele, L. Morbitzer,and W. Goyert Colloid Polym. Sci., 250, 797 (1972).Google Scholar
  4. 4).
    R. Bonart, Angew. Makromol. Chem., 58/59, 259 (1977).Google Scholar
  5. 5).
    J. Blackwell and K.H. Gardner, Polymer, 20, 13 (1979).CrossRefGoogle Scholar
  6. 6).
    L. Born, H. Hespe, J. Crone, and K.H. Wolf, Colloid Polym. Sci., 260, 819 (1982).CrossRefGoogle Scholar
  7. 7).
    Y. Camberlin, J.P. Pascault, M. Letoffe, and P. Claudy, J. Polym. Sci. Polym. Chem. Ed., 20, 1445 (1982).Google Scholar
  8. 8).
    Y. Camberlin and J.P. Pascault, J. Polym. Sci. Polym. Chem. Ed., 21, 415 (1983).Google Scholar
  9. 9).
    R.E. Camargo, C.W. Macosko, M. Tirrell, and S.T. Welling-hoff, Polym. Commun., 24, 314 (1983).CrossRefGoogle Scholar
  10. 10).
    C.D. Eisenbach and W. Gronski, Makromol. Chem. Rapid Commun., 4, 707 (1983).CrossRefGoogle Scholar
  11. 11).
    J.T. Kóberstein and R.S. Stein, J. Polym. Sci. Polym. Phys. Ed., 21, 1439 (1983).Google Scholar
  12. 12).
    J. Blackwell and C.D. Lee, J. Polym. Sci. Polym. Phys. Ed., 21, 2169 (1983).Google Scholar
  13. 13).
    R.M. Briber and E.L. Thomas, J. Macromol. Sci. Phys. Ed., B22, 509 (1983).Google Scholar
  14. 14).
    K.K.S. Hwang, D.J. Hemker, and S.L. Cooper, Macromolecules, 17, 307 (1984).ADSCrossRefGoogle Scholar
  15. 15).
    L.M. Leung and J. Koberstein, J. Polym. Sci. Polym. Phys. Ed., 23, 1883 (1985)Google Scholar
  16. 16).
    L. Born and H. Hespe, Colloid. Polym. Sci., 263, 335 (1985)CrossRefGoogle Scholar
  17. 17).
    R.M. Briber and E.L. Thomas, J. Polym. Sci. Polym. Phys. Ed., 23, 1915 (1985).Google Scholar
  18. 18).
    C.D. Eisenbach and Cl. Günter, Proc. Div. Polym. Mat. Sci. Eng., 49, 239 (1983).Google Scholar
  19. 19).
    W. Kern, K.J. Rauterkus, and H. Sutter, Makromol. Chem., 44, 78 (1961).CrossRefGoogle Scholar
  20. 20).
    L.L. Harrell, Jr., Macromolecules, 2, 607 (1969).ADSCrossRefGoogle Scholar
  21. 21).
    N.N. Ng, A.E. Allegrezza, R.W. Seymour, and S.L. Cooper, Polymer, 14, 255 (1973).CrossRefGoogle Scholar
  22. 22).
    H. Nefzger, Diploma thesis, University of Freiburg, 1984.Google Scholar
  23. 23).
    C.D. Eisenbach, in “35 Jahre Fonds der Chemischen Industrie”, Verband d. Chem. Indust., Ed., Frankfurt 1985, p. 77.Google Scholar
  24. 24).
    C.D. Eisenbach, H. Nefzger, M. Baumgartner, and Cl. Günter, Ber. Bunsenges. Phys. Chem., 89, 1190 (1985).CrossRefGoogle Scholar
  25. 25).
    Y. Camberlin and J.P. Pascault, J. Polym. Sci. Polym. Chem. Ed., 20, 383 (1982).Google Scholar
  26. 26).
    Z.Y. Qin, C.W. Macosko, and S.T. Wellinghoff, Proc. Div. Polym. Mater. Sci. Eng., 49, 475 (1983).Google Scholar
  27. 27).
    K.K.S. Hwang, G. Wu, S.B. Lin, And S.L. Cooper, J. Polym. Sci. Polym. Chem. Ed., 22, 1677 (1984).Google Scholar
  28. 28).
    Z.Y. Qin, C.W. Macosko, and S.T. Wellinghoff, Macromolecules, 18, 553 (1985).ADSCrossRefGoogle Scholar
  29. 29).
    J.A. Miller, S.B. Lin, K.K.S. Hwang, K.S. Wu, P.E. Gibson, and S.L. Cooper, Macromolecules, 18, 32 (1985).ADSCrossRefGoogle Scholar
  30. 30).
    Cl. Günter, Diploma thesis, University of Freiburg, 1982.Google Scholar
  31. 31).
    C.D. Eisenbach, M. Baumgartner, and Cl. Günter, Polym. Prepr., American Chemical Society, Div. Polym. Chem., 26 (2), 7 (1985).Google Scholar
  32. 32).
    C.D. Eisenbach, Cl. Günter, and U. Struth, Spez. Ber. KFA Jülich, 316, 107 (1985).Google Scholar
  33. 33).
    B. Fu, C. Feger, W.J. MacKnight, and N.S. Schneider, Polymer, 26, 889 (1985).CrossRefGoogle Scholar
  34. 34).
    B. Bengtson, C. Feger, W.J. MacKnight, and N.S. Schneider, Polymer, 26, 895 (1985).CrossRefGoogle Scholar
  35. 35).
    M. Baumgartner, Diploma thesis, University of Freiburg, 1983.Google Scholar
  36. 36).
    R. Bill, M. Dröscher, and G. Wegner, Makromol. Chem., 182, 1033 (1981).CrossRefGoogle Scholar
  37. 37).
    B. Böhmer, Dissertation, University of Mainz, 1968.Google Scholar
  38. 38).
    W. Kern and K.J. Rauterkus, Makromol. Chem., 28, 221 (1958).CrossRefGoogle Scholar
  39. 39).
    C.S. Schollenberger, U.S. Patent 2,871,218, filed Dec. 1, 1955, issued Jan. 27, 1959 (to BF Goodrich Company).Google Scholar
  40. 40).
    R.M. Carvey and D.E. Witenhafer, Brit. Patent 1,087,743, filed June 16, 1965, issued Oct. 18, 1967 (to BF Goodrich Company).Google Scholar
  41. 41).
    L.H. Peebles, Jr., Macromolecules, 9, 58 (1976).ADSCrossRefGoogle Scholar
  42. 42).
    L.H. Peebles, Jr., Macromolecules, 7, 872 (1974).ADSCrossRefGoogle Scholar
  43. 43).
    H. Suzuki, J. Polym. Sci., A-1, 9 (1971).Google Scholar
  44. 44).
    P.J. Flory, J. Amer. Chem. Soc., 58, 1877 (1936).CrossRefGoogle Scholar
  45. 45).
    R. Bonart and P. Demmer, Colloid Polym. Sci., 260, 518 (1982).CrossRefGoogle Scholar
  46. 46).
    P.J. Flory and A. Vrij, J. Amer. Chem. Soc., 85, 3548 (1963).CrossRefGoogle Scholar
  47. 47).
    H. Tadokoro, J. Polym. Sci. Polym. Symp., 15, 1 (1966).Google Scholar
  48. 48).
    P.G. Forcier and J. Blackwell, Acta Cryst. B37, 286 (1981).Google Scholar
  49. 49).
    L. Born, J. Crone, H. Hespe, E.H. Müller, and K.H. Wolf, J. Polym. Sci. Polym. Phys. Ed., 22, 163 (1984).Google Scholar
  50. 50).
    H. Nefzger and C.D. Eisenbach, to be published.Google Scholar
  51. 51).
    C.D. Eisenbach, Cl. Günter, M. Baumgartner, and U. Struth, Makromol. Kolloquium, Freiburg, February 1984.Google Scholar
  52. 52).
    Bayer, Das Diisocyanatpolyadditionsverfahren, Hanser, München, 1963, p. 14.Google Scholar
  53. 53).
    J.H. Saunders and K.C. Frisch, Polyurethanes, Chemistry and Technology, High Polymer Series Vol. XVI/1, Inter-science, New York, 1962, p. 103.Google Scholar
  54. 54).
    C.D. Eisenbach, Cl. Günter, and H. Hespe, to be published.Google Scholar
  55. 55).
    W.P. Yang, C.W. Macosko, and S.T. Wellinghof, Polym. Prepr. American Chemical Society, Div. Polym. Chem., 26 (2), 321 (1985).Google Scholar
  56. 56).
    C.S. Schollenberger and K. Dinbergs, J. Elastomers Plast., 11, 58 (1979); C.S.S. and K.D., Adv. Urethane Sci. Technol., 7, 1 (1979).Google Scholar
  57. 57).
    R.S. Seymour and S.L. Cooper, Macromolecules, 6, 48 (1973).ADSCrossRefGoogle Scholar
  58. 58).
    M. Baumgartner and C.D. Eisenbach, to be published.Google Scholar
  59. 59).
    C.G. Seefried, J.V. Koleske, and F.E. Critchfield, J. Appl. Polym. Sci., 19, 2493 (1975).CrossRefGoogle Scholar
  60. 60).
    J.L. Illinger, N.S. Schneider, and F.E. Karasz, Polym. Eng. Sci., 12, 25 (1972).CrossRefGoogle Scholar
  61. 61).
    D.S. Hüh and S.L. Cooper, Polym. Eng. Sci., 11, 369 (1971).CrossRefGoogle Scholar
  62. 62).
    C.G. Seefried, J.V. Koleske, and F.E. Critchfield, J. Appl. Polym. Sci., 19, 2503 (1975).CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media New York 1986

Authors and Affiliations

  • Claus D. Eisenbach
    • 1
  • Martin Baumgartner
    • 1
  • Claudia Günter
    • 1
  1. 1.Polymer-InstituteUniversity of KarlsruheKarlsruhe 1Germany

Personalised recommendations