Decomposition behavior of epoxy-resin systems cured by diamines

The kinetic of decomposition of two epoxy-resin systems cured by diamines has been investigated through thermogravimetric analysis measurements. The activation energies, E, of the decomposition of both systems were evaluated by an isothermal method and five dynamic methods reported in the literature. A single method to determine the type of mechanisms of decomposition was applied. The values of the activation energies obtained by these six methods for each studied system agree well when the degradation behavior of the system based in diglycidyl ether of bisphenol A was assumed to be of sigmoidal rate type and for the system based in tetraglycidyl-4,4′-diaminodiphenylmethane was assumed a deceleratory rate type. The information about the kinetic parameters based only on thermal degradation data has been used for a quick estimation of half-life time and lifetime of these systems at different temperatures.