Hostname: page-component-669899f699-7tmb6 Total loading time: 0 Render date: 2025-04-25T22:05:14.915Z Has data issue: false hasContentIssue false
  • English
  • Français

The Effect of Masked Isocyanates on the Mechanical Properties of My720/dds Epoxy Resin

Published online by Cambridge University Press:  22 February 2011

N. Rungsimuntakul ,
S.V. Lonikar ,
R. E. Fornes  and
R.D. Gilbert
N. Rungsimuntakul
Affiliation:
North Carolina State University, Fiber and Polymer Science Program, P. O. Box 8202, Raleigh, NC 27695-8202
S.V. Lonikar
Affiliation:
North Carolina State University, Fiber and Polymer Science Program, P. O. Box 8202, Raleigh, NC 27695-8202
R. E. Fornes
Affiliation:
Physics Department, P. O. Box 8202, Raleigh, NC 27695-8202
R.D. Gilbert
Affiliation:
North Carolina State University, Fiber and Polymer Science Program, P. O. Box 8202, Raleigh, NC 27695-8202
Get access

Abstract

The mechanical properties of epoxy resins and epoxy resin/graphite fiber composites are adversely affected by moisture absorption. Incorporation of masked isocyanates that unmask to release isocyanates in situ at the cure temperatures (150-177ºC) reduce the equilibrium absorption up to ∼70%. Dynamic mechanical analyses and stress-strain properties of epoxy resins containing masked isocyanates were examined to determine their effect on mechanical properties. The ultimate Tg of the epoxy is reduced by incorporation of masked isocyanate, but the actual Tg is comparable to the “as cured” Tg of the epoxy. The dynamic moduli up to the Tg are relatively unaffected. Ina number of cases, the initial modulus, elongation at break and peak stress are equal or better than the unmodified resins.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 171: Symposium O – Polymer Based Molecular Composites , 1989 , 371
Copyright
Copyright © Materials Research Society 1990

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

Article purchase

Temporarily unavailable

References

REFERENCES

1. Fisher, C.M., Gilbert, R.D., Fomes, R. E., and Memory, J. D., J. Polym. Sci.: Polym. Chem. Ed., 23, 2931 (1985).Google Scholar
2. Hu, H.P., Gilbert, R. D., and Fornes, R. E., J. Polym. Sci., Part A, Polym. Chem. Ed., 25 (5), 1235 (1987).Google Scholar
3. Lonikar, S. V., Rungsimuntakul, N., Gilbert, R. D. and Fomes, R. E., J. Polym. Sci., Polym. Chem. Ed., accepted for publication.Google Scholar
4. Wilson, T. W., Fomes, R. E., Gilbert, R. D., and Memory, J. D., J. Polym. Sci.: Part B: Polym. Phys., 26, 2029 (1988).Google Scholar
5. Keenan, J. D., Master Thesis, University of Washington, Seattle, 1979.Google Scholar
6. Nielsen, L. E., Mechanical Properties of Polymers and Composites, Vol. 2, Marcel Dekker Inc., New York, 1974.Google Scholar
7. Murayama, T. and Bell, J. P., J. Polym. Sci., Part A-2, 8, 437 (1970).Google Scholar
8. Hata, N., Yamauchi, R. and Kumanotani, J., J. Appl. Polym. Sci., 17, 2173 (1973).Google Scholar
9. Hata, N. and Kumanotani, J., J. Appl. Polym. Sci., 21, 1257 (1977).Google Scholar
10. Sauer, J. A., J. Polym. Sci., Part C: Polym. Symp., 32, 69 (1971).Google Scholar
11. Morgan, R. J., in “Advances in Polymer Science No. 72”, Dusek, K., Ed., Springer-Verlag, New York, 1985, p.1.Google Scholar