PAEK/BMI共混体系分相机理及其层状体系相形态的初步研究

采用原子力显微镜研究了PAEK/双马来酰亚胺共混体系的分相机理和层状体系固化后的相形态结构.通过AFM可以清楚地观察到,PAEK含量较低时,分相机理是成核-增长机理(Nucleation and Growth mechanism,简称NG),形成典型的海岛分相结构;随着PAEK含量的增加,分相机理变成旋节线相分离机理(Spinodal Decomposition,简称SD),形成了典型的双连续结构,随着PAEK的含量进一步增大,形成典型的相反转结构,SEM观察证实了AFM观察的相分离机理.同时共混物的冲击强度在PAEK含量为20phr时出现了一个峰值,此时共混体系的冲击强度提高了近2倍.通过SEM研究PAEK/双马来酰亚胺层状体系,发现PAEK膜与BMI相互接触的区域,由于相互扩散出现了类似共混体系的相形态结构,其中由于BMI的扩散能力较PAEK较强,发现在PAEK相出现大量BMI颗粒,这种结构对于提高双马来酰亚胺树脂的韧性非常有利,通过研究PAEK/双马来酰亚胺共混体系的分相机理及其层状结构的相形态结构,从而为PAEK膜"离位"增韧BMI树脂基复合材料打下基础.

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 structnre 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 20phr PAEK,approximately increasing 2 times than the neat BMI matrix.The laminated PAEK/BMI system has the similar phase morphology structnre like the blend system.In the region of two matrices,three typical phase structure were observed.This typical phase morphology structnre 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.