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

Abstract

Abstract A 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, 1 H 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 ( E a ) 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 T g 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