Thermal oxidation of diallylbisphenol A - bismaleimide networks. Comonomer effect and kinetic modelling

Pure BMI resin based on 4,4′-bismaleimidodiphenylmethane (BMI) and its copolymers with various quantities of 2,2′-diallylbisphenol A (BMI-DABPA 2–1, BMI-DABPA 1–1, BMI-DABPA 1–2) were thermally aged. Ageing at 160 °C was monitored by FTIR and showed the greatest reactivity of diallyl groups which accelerate the degradation of BMI-DABPA copolymers. It was confirmed by a gravimetric study of ageing under nitrogen or oxygen at 350 and 375 °C. A co-oxidation kinetic model was proposed for describing the oxidation of BMI and BMI-DABPA systems. The effect of the main kinetic parameters was discussed from a parametric study. The main rate constants were estimated from the fitting of experimental curves and comparable gravimetric data from literature.