Preliminary study on phase separation mechanism of PAEK/BMI blends and laminated system with morphology

The phase separation mechanism of PAEK/BMI blend was studied by AFM and phase morphology structure of the PAEK/BMI laminated system was also investigated. The AFM images clearly showed the phase separation mechanism of PAEK/BMI blend, with low content of PAEK, the phase separation progresses according to the Nucleation and Growth mechanism, which leads to the typical phase morphology-sea-island structure. With the content of PAEK increasing, the Spinodal Decomposition mechanism happens and the typical co-continuous phase structure was observed. The content of PAEK further increasing, inverted phase morphology occurred in the blend. The phase separation mechanism observed by AFM was verified by SEM. The impact strength of the blend reached peak value with the 20 phr PAEK, approximately increasing 2 times than the neat BMI matrix. The laminated PAEK/BMI system has the similar phase morphology structure like the blend system. In the region of two matrices, three typical phase structure were observed. This typical phase morphology structure between PAEK and BMI phase was good for improving the toughness of BMI resin and the composite based on the BMI matrix. Sequentially, the above study makes good foundation for using the typical phase morphology structure to improve the toughness of the composites based on BMI matrix by ex-situ concept.