Hygrothermal Effects on Painted and Unpainted Glass/Epoxy Composites—Part A: Moisture Absorption Characteristics

Abstract

Moisture diffusion behaviour of glass/epoxy composites coated with a polyurethane base paint and those without the paint were studied on immersion in water at 323 K. Neat resin castings of the epoxy resin system were also studied for comparison. The composite specimens with paint showed lower moisture absorption values than those of the unpainted specimens subjected to the same immersion conditions. The diffusion parameters obtained from the experiment conducted up to saturation limits agreed well with the data computed using moisture absorption programme (M8 gain) proposed by G. S. Springer. The mixture rule for moisture absorption was also verified for the weight fraction studied. Further, Fickian correlation was found to exist in all the cases.

Keywords

glass/epoxy composites maximum moisture content Fickian diffusion diffusion coefficient

Get full access to this article

View all access options for this article.

References

1. Loos A. and G. S. Springer , 1979, “Moisture absorption of graphite epoxy composites immersed in liquids and in humd air,” J. of Composite Materials, 13:131–147.

2. “Transactions of the workshop on the effects of relative humidity and elevated temperature on composite structures,” Report AFSOR TR-77-0030, University of Delaware, Newark, Delaware, March 1976.

3. Springer G. S. , 1998, Environmental Effects on Composite Materials, Vol. 3, G. S. Springer , ed., Lancaster, PA: Technomic Pub. Co., Inc., pp. 1–34.

4. Blikstad M. , P. O. W. Sjoblom and T. R. Johannesson , 1984, J. of Composite Materials, 18:32–46.

5. Srihari S. and R. M. V. G. K. Rao , “Hygrothermal characterisation and diffusion studies on carbon/epoxy composites,” J. of Reinforced Plastics and Composites, 18:921–927.

6. Srihari S. and R. M. G. V. K. Rao , “Hygrothermal characterisation and diffusion studies on glass/epoxy composites,” J. of Reinforced Plastics and Composites, 18:942–953.

7. Bonniau P. and A. F. Bunsell , 1981, “A comparative study of water absorption theories applied to glass epoxy composites,” J. of Composite Materials, 15:272–293.

8. Rao R. M. V. G. K. , N. Balasubramanium and M. Chanda , 1984, J. of Reinforced Plastics and Composites, 3(3):232–245.

9. Rao R. M. V. G.. K. , N. Balasubramanium and M. Chanda , 1984, J. of Reinforced Plastics and Composites, 3(3):246–253.

10.

10. Shen C. H. and G. S. Springer , 1976, J. of Composite Material, 10:2–20.

11.

11. Crank J. , 1975, The Mathematics of Diffusion, Second Edition. Oxford, U.K. Clarendon Press.

12.

12. Springer G. S. , 1981, Environmental Effects on Composite Materials, Technomic Publishing Co., Inc., Lancaster, PA.

13.

13. Springer G. S. , Environmental Effects on Composite Materials, Vol. 2, pp. 151–161.

14.

14. Jost W. , 1960, Diffusion in Solids, Liquids, Gases. Academic Press, Inc., Publishers Netword and London.