Cure kinetics and thermal degradation characteristics of epoxy/polyetheramine systems

In this paper, we report detailed cure kinetics of epoxy and polyetheramine (Jeffamine) systems. Three cured epoxy networks were prepared by using three types of Jeffamines having different molecular masses and polyether segment in the chain. The effect of epoxy to Jeffamine stoichiometric and sub-stoichiometric ratios and molecular mass of Jeffamines on curing behaviour, mechanical properties and thermal behaviour of the resulting networks were investigated. The results were explained using Fourier transform infrared (FTIR) spectroscopic analysis. The epoxy systems with optimised epoxy/amine ratios were studied for their cure behaviour using temperature modulated differential scanning colorimetric (MDSC) analysis. Isoconversion kinetics was studied to find out activation energy, pre-exponential factor. The conversion function, f(a) was found to be fitting as Sestak-Berggren model. Thermal behaviour of the epoxy networks was determined by a non-isothermal thermogravimetric analysis (TGA) both in nitrogen and air envelop. The thermal stability of the rubbery epoxy systems is observed to be much better than the conventional rubbers having unsaturation.