Fabrication and Characterization of a Modified Conjugated Molecule-Based Moderate-Temperature Curing Epoxy Resin System

Abstract

A 2-Methylimidazole derivative [ethyl glycidyl ether (EGE)–2-MI] was synthesized through the reaction of EGE with the conjugated molecule 2-MI. The structure was confirmed by Fourier transform infrared spectroscopy, 1H-nuclear magnetic resonance spectroscopy, and differential scanning calorimeter. The synthesized EGE–2-MI was applied in epoxy resin E-51 as a latent curing agent. Kinetics of the curing reaction were studied by a differential scanning calorimeter method, optimum curing process parameters were determined, storage life of the resin system at room temperature was evaluated, and mechanical properties of the moderate-temperature-cured products were also tested and analyzed. The results revealed that the epoxy resin system using EGE–2-MI as the curing agent can be efficiently cured at 110–120°C, with an activation energy of 86.34 kJ/mol. The storage period of the EGE–2-MI/cyanate resin system can reach 14 days under ambient temperature. In addition, the cured mixture with EGE–2-MI/cyanate resin has a tensile strength of 40 MPa and an Al–Al adhesion shear strength of 20.11 MPa.