Kinetic study of Diels–Alder reaction involving in maleimide–furan compounds and linear polyurethane

Linear polyurethane was synthesized by Diels–Alder (DA) reaction between a polyurethane prepolymer end-capped with furan rings (MPF) and bismaleimide (BMI). The polymerization kinetics were studied following a preliminary kinetic study of the DA reaction between furfuryl alcohol (FA) and BMI compounds by attenuated total reflection infrared, ultraviolet–visible and in situ 1H NMR spectroscopies, where in situ 1H NMR spectroscopy was selected as the analytical method of choice to study the DA reaction between MPF and BMI. The results showed that the reaction followed second-order kinetics, and the most beneficial experimental conditions to maximize conversion were identified.