Curing Kinetics of Waterborne Blocked Polyisocyanate/Hydroxyl Polyacrylic System

TGA/DSC simultaneous thermal analyzer was used to study the curing kinetics of the waterborne blocked polyisocyanate and hydroxyl polyacrylic system. TG and DSC curves were obtained at four different heating rates including 5 ℃/min, 10 ℃/min, 15 ℃/min and 20 ℃/min. After abnormal TG curve occurred at 20 ℃/min, the curing kinetics with and without according DSC data were calculated for comparison. The results show that because of the great influence of the abnormal TG data on the curing kinetics, the DSC data according to the abnormal TG data cannot be used to calculate the curing kinetics. The apparent activation energy is 47.88 kJ·mol-1, the apparent frequency factor is 5.82×107 s-1, and the evaluated reaction order is 0.90.