Curing mechanisms and kinetic analysis of DGEBA cured with a novel imidazole derivative curing agent using DSC techniques

Abstract

AbstractA novel imidazole derivative, 2MI‐g‐CA, was obtained through the reaction of 2‐methylimidazole (2MI) and cyanuric acid (CA) and characterized by means of elemental analysis, FTIR spectroscopy, 1H NMR spectroscopy, and mass spectrometric analysis. The curing mechanisms and kinetics of diglycidyl ether of bisphenol A (DGEBA) using 2MI and 2MI‐g‐CA as curing agents were studied with differential scanning calorimetry (DSC) under dynamic and isothermal conditions. Both dynamic and isothermal DSC thermograms of DGEBA/2MI system showed two distinct exothermic peaks, whereas those of DGEBA/2MI‐g‐CA system showed only one distinct exothermic peak. These results indicated that the two systems have different initiation curing mechanisms. The apparent activation energies (Ea) obtained from DSC scanning runs using the Kissinger and Ozawa methods were 79.0, 83.0 kJ/mol and 84.2, 88.8 kJ/mol for DGEBA/2MI and DGEBA/2MI‐g‐CA systems, respectively. These values suggested the novel curing agent 2MI‐g‐CA exhibited greater levels of latency during cure or increased the pot life of epoxy resin system. In addition, under the same curing condition, the Tg values of DGEBA/2MI‐g‐CA system were about 25°C higher than those of DGEBA/2MI system, exhibiting a better thermal stability. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010