I would like to know if it is possible to cure them at less than 80°C in particular.
Please see the link below. The company provides dozen of anhydrides for curing epoxy resins & offers information about applications.
I must say that thanks to your good question, I would have been still thinking that curing epoxy resins requires more than 100 oC but the company talked about curing at 70 oC !
http://www.broadview-tech.com/products/specialtyanhydrides.aspx
You can play with the quantity of amine, which is the catalyst or test anyother catalyst. However, at 80ºC you will vitrify and the crosslinking degree achieved will be not the highest you can reach at higher temperature. It also depends on the anhydride and the resin.
Dear all;
I have to look for a good and recent documents which in fact resumes both answers of Dr. Nizar and Dr. Serra. The conclusion of this document states that it is possible to lower the curing temperature using amine activators but not to the point where viscosity is sufficiently high so that the factor "diffusion controlled kinetics" becomes important, here the system curing process falls in the the problem quoted by Dr. Serra. In fact a compromise must be achieved in order to balance between the curing conditions and the final product properties. Regards
I agree with all and I want to add also molecular weights of the ingredients important and effects your viscosity. You should choose your ingredients accordingly not to have diffusion problems
The problem is not only choosing ingredients with low viscosity but that the viscosity increases very much in gelation when the curing proceeds. If you are curing below Tg the reaction stops because you reach vitrification. If you want to continue the curing process the tempearturre should be increased to surpass vitrification. I recommend to learn about TTT diagrams published for epoxy curing and you can realize that the conversion achieved can be quite low if the curing temperature does not surpasses the Tg of the final thermoset.
Dear all;
these documents shed some light on the question. Regards
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