Multivariate Curve Resolution—Alternating Least Squares and Kinetic Modeling Applied to Near-Infrared Data from Curing Reactions of Epoxy Resins: Mechanistic Approach and Estimation of Kinetic Rate Constants

This study describes the combination of multivariate curve resolution–alternating least squares with a kinetic modeling strategy for obtaining the kinetic rate constants of a curing reaction of epoxy resins. The reaction between phenyl glycidyl ether and aniline is monitored by near-infrared spectroscopy under isothermal conditions for several initial molar ratios of the reagents. The data for all experiments, arranged in a column-wise augmented data matrix, are analyzed using multivariate curve resolution–alternating least squares. The concentration profiles recovered are fitted to a chemical model proposed for the reaction. The selection of the kinetic model is assisted by the information contained in the recovered concentration profiles. The nonlinear fitting provides the kinetic rate constants. The optimized rate constants are in agreement with values reported in the literature.