Studies on the Gelation of Epoxy Resin with Amines by Viscosity Determination

Abstract

At the reaction of Epon 828 with n-butylamine and ethylenediamine in mixed benzeneethylalcohol solution the increase of viscosity with reaction time was well represented by equation ηγ=1+αt-At² (n-butylamine) and ηγ= 1/(1-αt+Bt²)(ethylenediamine), where ηγ is (solution viscosity at time t)/(solution viscosity at time 0):α, A, , β and B are constants. a and β was proportioned to the product of the initial concentration of reagents (amine and epoxide), and increased with the temperature and the content of ethylalcohol in solvent. The apparent activation energy of reaction calulated from the temperature dependence of a and β were 11.6-11.8 kcal/mol and 13.2 kcal/mol, respectively.
From the relationship between β and the extent of reactionit was found that course of the reaction could be pursued by viscosity measurement.