Journal of Materials Science

, Volume 23, Issue 9, pp 3073–3082 | Cite as

Fracture toughness and molecular structure of unfilled epoxy adhesives

  • Jessica A. Schroeder


The cohesive, mode I (tensile cleavage) fracture energy (or fracture toughness), GIc, of bulk tapered double cantilevered beam (TDCB) samples of a series of three epoxy thermoset networks was determined using a linear elastic fracture mechanics (LEFM) analysis. Networks of different crosslink density were obtained by mixing various amounts of an aromatic epoxy novolac and an aliphatic epoxy and crosslinking with an imidazole catalyst. Brittle, stick-slip fracture was observed for all formulations, with GIc increasing as the amount of aliphatic epoxy increased. However, fracture surface morphologies exhibited evidence of increasing plastic deformation as GIc increased. In the investigation of structure-property relationships for this series of thermoset networks, GIc was found to be inversely related to both network crosslink density and glass transition temperature (Tg). It was also found that the room temperature frequency of the glassy state transition (β-transition) increased as fracture toughness increased.


Epoxy Fracture Toughness Glass Transition Temperature Cantilever Beam Crosslink Density 
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.
    A. A. Griffith, Phil. Trans. R. Soc. A221 (1920) 163.Google Scholar
  2. 2.
    E. Orowan, Rep. Prog. Phys. 12 (1948) 185.Google Scholar
  3. 3.
    G. R. Irwin, J. Appl. Mech. Trans. ASME 24 (1957) 361.Google Scholar
  4. 4.
    A. J. Kinloch and R. J. Young, “Fracture Behavior of Polymers” (Applied Science Publishers, New York, 1983) Chapter 3.Google Scholar
  5. 5.
    G. Pritchard and G. V. Rhoades, Mater. Sci. Eng. 26 (1976) 1, and references therein.Google Scholar
  6. 6.
    L. J. Broutman and F. J. McGarry, J. Appl. Polym. Sci. 9 (1965) 609.Google Scholar
  7. 7.
    R. P. Kambour, A. S. Holik and S. Miller, J. Polym. Sci., Polym. Phys. Edn 16 (1978) 91.Google Scholar
  8. 8.
    G. P. Marshall, L. E. Culver and J. G. Williams, Proc. R. Soc. Lond. A319 (1970) 165.Google Scholar
  9. 9.
    A. J. Kinloch and R. J. Young, “Fracture Behavior of Polymers” (Applied Science Publishers, New York, 1983) Chapter 7.Google Scholar
  10. 10.
    Idem, ibid. Chapter 8.Google Scholar
  11. 11.
    W. D. Bascom, R. L. Cottington, R. L. Jones and P. Peyser, J. Appl. Polym. Sci. 19 (1975) 2545.Google Scholar
  12. 12.
    R. A. Gledhill, A. J. Kinloch, S. Yamini and R. J. Young, Polymer 19 (1978) 574.Google Scholar
  13. 13.
    R. Y. Ting and R. L. Cottington, Adh. Age 24 (1981) 35.Google Scholar
  14. 14.
    R. A. Gledhill and A. J. Kinloch, Polym. Eng. Sci. 19 (1979) 82.Google Scholar
  15. 15.
    R. Griffiths and D. G. Holloway, J. Mater. Sci. 5 (1970) 302.Google Scholar
  16. 16.
    J. Mijović, J. Appl. Polym. Sci. 25 (1980) 1179.Google Scholar
  17. 17.
    S. Mostovoy and E. J. Ripling, ibid. 15 (1971) 661.Google Scholar
  18. 18.
    J. Mijović, ibid. 27 (1982) 2919.Google Scholar
  19. 19.
    D. L. Hunston, J. L. Bitner, J. L. Rushford, J. Oroshnik and W. S. Rose, J. Elast. Plast. 12 (1980) 133.Google Scholar
  20. 20.
    A. J. Kinloch, S. J. Shaw and D. L. Hunston, Polymer 24 (1983) 1355.Google Scholar
  21. 21.
    D. L. Hunston and W. D. Bascom, in “Rubber-Modified Thermoset Resins”, edited by C. K. Riew and J. K. Gillham (American Chemical Society, Washington, DC, 1984) p. 101.Google Scholar
  22. 22.
    S. Mostovoy and E. J. Ripling, J. Appl. Polym. Sci. 15 (1971) 611.Google Scholar
  23. 23.
    S. Yamini and R. J. Young, Polymer 18 (1977) 1075.Google Scholar
  24. 24.
    E. J. Ripling, J. S. Santner and P. B. Crosley, J. Mater. Sci. 18 (1983) 2274.Google Scholar
  25. 25.
    G. P. Anderson, K. L. Devries and M. L. Williams, Int. J. Frac. 10(5) (1974) 565.Google Scholar
  26. 26.
    E. J. Ripling, S. Mostovoy and H. T. Corten, J. Adhesion 3 (1971) 107.Google Scholar
  27. 27.
    A. F. Farkas and P. F. Strom, J. Appl. Polym. Sci. 12 (1968) 159.Google Scholar
  28. 28.
    SHELL CHEMICAL COMPANY, Epon® Resin Structural Reference Manual.Google Scholar
  29. 29.
    F. Ricciardi, W. A. Romanchick, M. M. Joullie, J. Polym. Sci., Polym. Chem. Edn 21 (1983) 1475.Google Scholar
  30. 30.
    J. A. Schroeder, P. A. Madsen and R. T. Foister, Polymer 28 (1987) 929.Google Scholar
  31. 31.
    J. M. Scott, G. M. Wells and D. C. Phillips, J. Mater. Sci. 15 (1980) 1436.Google Scholar
  32. 32.
    R. Y. Ting and R. L. Cottington, J. Appl. Polym. Sci. 25 (1980) 1815.Google Scholar
  33. 33.
    A. J. Kinloch, S. J. Shaw, D. A. Todd and D. L. Hunston, Polymer 24 (1983) 1341.Google Scholar
  34. 34.
    A. C. Moloney, H. H. Kausch and H. R. Stieger, J. Mater. Sci. Lett. 3 (1984) 776.Google Scholar
  35. 35.
    S. Mostovoy and E. J. Ripling, J. Appl. Polym. Sci. 10 (1966) 1351.Google Scholar
  36. 36.
    S. Mostovoy, E. J. Ripling and C. F. Bersch, J. Adhesion 3 (1971) 125.Google Scholar
  37. 37.
    S. Mostovoy, P. B. Crosley and E. J. Ripling, J. Mater. Sci. 2 (1967) 661.Google Scholar
  38. 38.
    S. Yamini and R. J. Young, ibid. 15 (1980) 1823.Google Scholar
  39. 39.
    R. L. Patrick, W. G. Gehman, L. Dunbar and J. A. Brown, J. Adhesion 3 (1971) 165.Google Scholar
  40. 40.
    B. W. Cherry and K. W. Thomson, J. Mater. Sci. 16 (1981) 1925.Google Scholar
  41. 41.
    D. C. Phillips, J. M. Scott and M. Jones, ibid. 13 (1978) 311.Google Scholar
  42. 42.
    A. J. Kinloch and J. G. Williams, ibid. 15 (1980) 987.Google Scholar
  43. 43.
    A. C. Moloney and H. H. Kausch, J. Mater. Sci. Lett. 4 (1985) 289.Google Scholar
  44. 44.
    D. C. Timm, A. J. Ayorinde and R. F. Foral, Brit. Polym. J. 17(2), (1985) 227.Google Scholar
  45. 45.
    E. Sacher, J. Appl. Polym. Sci. 19 (1975) 1421.Google Scholar
  46. 46.
    R. F. Boyer, Polymer. 17 (1976) 996.Google Scholar

Copyright information

© Chapman and Hall Ltd 1988

Authors and Affiliations

  • Jessica A. Schroeder
    • 1
  1. 1.Polymers DepartmentGeneral Motors Research LaboratoriesWarrenUSA

Personalised recommendations