Polymerization kinetics of reactive N,N′-bismaleimide-4,4′-diphenylmethane/barbituric acid based microgel particles

• Non-isothermal polymerization kinetics of reactive BMI/BTA microgel particles studied.
• Kinetic parameters for polymerizations of reactive BMI/BTA MPs determined.
• Polymerization processes adequately described by a contracting cylinder model.
• Free radical polymerization plays a crucial role in the temperature range 70–95 °C.
• Michael addition polymerization becomes significant at T higher than 120 °C.

Non-isothermal polymerization kinetics of reactive N,N′-bismaleimide-4,4′-diphenylmethane/barbituric acid microgel particles (BMI/BTA MPs) and BMI/BTA/hydroquinone (HQ) MPs in N-methyl-2-pyrrolidone (NMP) solution studied. The model-fitting method in combination with the model-free method was used to determine the kinetic parameters for the polymerizations of reactive BMI/BTA MPs and BMI/BTA/HQ MPs. The results show that Michael addition polymerization predominates in BMI/BTA/HQ MPs in the temperature range 95–140 °C. For BMI/BTA MPs, free radical polymerization plays a crucial role in the temperature range 70–95 °C, whereas Michael addition polymerization becomes significant when the temperature is higher than 120 °C. The non-isothermal polymerization processes were satisfactorily predicted by the same contracting cylinder model for both the BMI/BTA MPs and BMI/BTA/HQ MPs.