Kinetic Study of Infrared Heat Curing of Thermosetting Polymers

Infrared (IR) radiation curing technology has a high potential to improve the curing process of thermosetting polymers. To investigate the IR curing reaction mechanism, the present study explores the curing kinetics of glycidyl methacrylate (GMA)/dodecanedioic acid (DDDA) powder coatings subjected to IR radiation. Fourier-transformed infrared (FT-IR) spectroscopy is employed to record the concentration of epoxide groups with respect to time under different temperature conditions, with the reaction conducted under IR radiation. The resulting data are then fitted by the Levenberg–Marquardt algorithm using MATLAB software to obtain the kinetic parameters, namely the rate constant (k), catalytic constants (n, m), manifestation activation energy (E), and the pre-exponential factor (A) of the curing reaction. Additionally, this study proposes a new concept: the ‘photo-thermal synergistic effect’ of infrared curing and its evaluation criteria using a dimensionless quantity. Incredibly, this index integrates the impact of IR curing technology on two aspects: the curing process and the properties of the cured product. Overall, this study deepens our understanding of the IR curing reaction mechanism and provides a reference for the application of this technology in practical engineering.