Curing Behavior and Adhesion Performance of a One‐Component Epoxy Resin Based on a Dual‐Locked Thermal Latent Curing Agent

ABSTRACT

Thermally latent curing agents are essential for improving the storage stability of one‐component epoxy resins. In this study, the curing behavior of a one‐component epoxy resin based on a diglycidyl ether of bisphenol A (DGEBA)/dual‐locked curing agent (DCA) system was quantitatively investigated using isothermal and nonisothermal differential scanning calorimetry (DSC) and Fourier transform near‐infrared spectroscopy (FT‐NIR). Analysis of the T _g –conversion relationship using the DiBenedetto equation yielded a maximum glass transition temperature ( T _g∞ ) of 155°C. The apparent activation energy as a function of conversion was determined using the Friedman method, and a time–temperature–transformation (TTT) diagram was constructed. Tensile shear tests on iron substrates demonstrated high bond strength under optimized curing conditions. These results indicate that the DCA‐based one‐component epoxy resin is a promising adhesive with both excellent storage stability and curing performance.