Microcapsule-modified bismaleimide (BMI) resins

Poly(urea–formaldehyde) microcapsules filled with epoxy resins (MCEs) were added into 4,4′-bismaleimidodiphenylmethane/O,O′-diallylbisphenol A (BMI/BA) system to develop a novel BMI/BA/MCEs resin system. The effects of MCEs on the reactivity of BMI/BA system were investigated by Fourier-transform infrared (FTIR) spectra and differential scanning calorimetry (DSC). The mechanical properties of systems such as flexural strength and impact resistance were evaluated. The morphologies of systems were characterized using scanning electronic microscope (SEM). The thermal stability of systems was investigated using thermogravimetric analysis (TGA). Results show that the addition of MCEs has no significant influence on the reactivity of BMI/BA system. The size and content of MCEs have significant effects on the mechanical properties of BMI/BA system. Comparing with BMI/BA resin, BMI/BA/MCEs system with appropriate content of MCEs have improved flexural strength, the impact resistance and water resistance but slightly weakened initial thermal decomposition temperature (Td).