Curing kinetics of phenolphthalein-aniline-based benzoxazine investigated by non-isothermal differential scanning calorimetry

To understand the curing processes of phenolphthalein-aniline-based benzoxazine (BP-a), the curing kinetics of bisphenol A-aniline-based benzoxazine and BP-a were investigated using non-isothermal differential scanning calorimetry (DSC) at different heating rates. Kissinger, Ozawa, Friedman and Flynn-Wall-Ozawa methods were used to determine the kinetic parameters and built the kinetic models. According to the results, BP-a displays two dominant curing processes, namely the autocatalytic curing process at low-temperature curing (reaction (1)) with the average activation energy of 95.0-98.5 and nth-order curing process at elevated temperature curing (reaction (2)) with the average activation energy of 124.0-126.2 kJ mol(-1). Moreover, the predicted curves from the kinetic models fit well with the non-isothermal DSC curve. Non-isothermal differential scanning calorimetry is a promising method to help researchers explore the application of BP-a and other arylamine Mannich bridge structures containing polybenzoxazines.