Phase structure and thermal properties of bismaleimide/polyethersulfone multi-phase resin system

Abstract

The effect of micro phase morphology of bismaleimide (BMI)/polyethersulfone (PES) multi-phase system on the thermal properties was studied by SEM, DMA and TGA. The SEM results suggest that the phase separation exists in the multi-phase BMI/PES resin. Phase inversion happens with the addition of PES up to 15 phr. SEM shows that the subtle micro structure with fine BMI-rich particulate phases is surrounded by continuous PES-rich phase. The glass transition temperature (Tg) belonging to BMI-rich phase of BMI/PES resin is higher than neat BMI resin. BMI/PES-5 resin system exhibits only one Tg and the temperature corresponding to the decrease of initial modulus increased. The high-temperature plastic behavior of BMI/PES resin system is enhanced with the increase of PES. The peak thermal decomposition temperature and char yield of BMI/PES resin are enhanced owing to the excellent interface interaction between BMI and PES as well as the thermal protection effect of PES. The heat resistance of resin systems under N2 atmosphere are superior to the systems under air atmosphere.

Keywords

• polyethersulfone (PES)
• bismaleimide (BMI)
• phase structure
• glass transition
• dynamic thermomechanical analysis (DMA)
• thermogravimetric analysis (TGA)