How is it possible to model it? I know there are a lot of different epoxy resins but is there a macromodel available?
A lot of work hasbeen done on water uptake by epoxy composites and on the hydrothermal aging of epoxy composites, but these are fairly complex systems and the hydrothermal degradation phnomena are influenced as much by the interface as by the matrix resin. (Including hydrolytic effects of the coupling agents). In principle neither the ether nor the amine bond is sensitive to hydrolysis, only the ester bond. I do not remember to have read articles on the mechanism of water induced degradation of epoxies.
A lot of work hasbeen done on water uptake by epoxy composites and on the hydrothermal aging of epoxy composites, but these are fairly complex systems and the hydrothermal degradation phnomena are influenced as much by the interface as by the matrix resin. (Including hydrolytic effects of the coupling agents). In principle neither the ether nor the amine bond is sensitive to hydrolysis, only the ester bond. I do not remember to have read articles on the mechanism of water induced degradation of epoxies.
Dear Bahman
As stated in the previous response, this can be quite complex, but macroscopic models are available to represent the global sorption/desorption mechanisms. This can also depends stromgly on the curing agent you are using, and of the curing level. I refer you to this paper in which we introduced a macroscopic diffusion/reaction model that is also validated from a physical point of view. Don't hesitate to contact if more questions:
J. El Yagoubi, G. Lubineau and F. Roger (2012). A fully coupled diffusion-reaction scheme for moisture absorption-desorption in an anhydride-cured epoxy resin. Polymers, v. 39, pp. 33-41.
Thanks a lot for your prompt answers. It was really helpful. I will read the article and send you my feedback.
I have searched a lot. But as correctly stated in your answers, the phenomenon is complex and depends on a lot of variables such as curing, the epoxy resin,... I have dome some moisture absorption tests on my epoxy resin and I have measured the tensile strength degradation with time. However, I dont know if its possible to model this degradation mathematically considering the water-epoxy chemical reactions, hydrolysis, plasticization, ..etc.
Hi Bahman. That's exactly what we tried to do in this paper. You can use the phenomenological model as a starting point. New papers will come soon with the relations to moduli especially during extreme temperature cycling. Best
Batman,
See for instance references corresponding to the topic in my researchgate page.
Best regards
Thanks Frederic. I see many interesting publications in your page. Thanks a lot. I will send you my feedback.
Kind regards.
Thanks also because it also helped me a lot. However just to mention a mistake in the reference to your article, Mr Lubineau. It's in the volume 53 in the journal Polymer (without s at the end) :-).
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