Study of the Cure of a Diglycidyl-Ether of Bisphenol-a (DGEBA) / Triethylenetetramine (TETA) Epoxy System by Non-Isothermal Differential Scanning Calorimetry (DSC)

A diglycidyl-ether of bisphenol-A (DGEBA)/Triethylenetetramine (TETA) system was studied by non-isothermal differential scanning calorimetry (DSC) to establish its kinetics of cure. The DGEBA resin was Araldite GZ 601 X75 used in the marine coatings formulations. Previously, the optimum resin/hardener ratio was determined by the reaction heat measuring (.Hc) calculated from the curing exothermic peak. Tests at different heating rates (10, 15, 20, 25 and 30°C/min) under inert atmosphere were carried out in order to study the reaction kinetics. The activation energy of the cure (Ea) was obtained from these tests data by Borchardt-Daniels, autocatalytic, Duswalt and isoconversional Ozawa methods. Once the activation energy was determined, the master curves method was applied to find the kinetic model which best describes the measured DSC data. The Sestak-Berggren model SB (m,n) was found to be the most adequate for the system studied.