Study on Curing Kinetics and Viscosity Modeling of High‐Performance Bismaleimide Resin

Bismaleimide (BMI) resin is widely used in high‐performance composites, and its curing and rheological behavior are crucial for process design. In this study, a three‐component BMI resin composed of diphenylmethane‐type bismaleimide resin, T‐type bismaleimide resin, and diallylbisphenol A was investigated by differential scanning calorimetry (DSC) and rotational rheometry. Non‐isothermal DSC results showed that the exothermic peak shifted to higher temperatures with increasing heating rate, and the characteristic curing temperatures obtained by T–β extrapolation were T i = 174.31°C, T p = 210.44°C, and T f = 252.54°C. The average apparent activation energy calculated within the conversion range of 0.2 ≤ α ≤ 0.8 was 78.36 kJ/mol. Based on Málek analysis, the curing reaction followed an autocatalytic kinetic model, with average kinetic parameters of m = 0.234, n = 1.029, and A = 3.59 × 10 5 . The viscosity evolution was well described by the Double Arrhenius viscosity model, with key model parameters of k 1 = 1.341 × 10 −6 , k 2 = 4538.4, k 3 = 1.509 × 10 4 , and k 4 = −5682.3, showing good agreement between the predicted and experimental results. These established models provide guidance for optimizing BMI curing schedule design, resin infusion temperature selection, and injection time window.