聚醚砜增韧双马来酰亚胺树脂研究

选择韧性，耐热性不同的两种典型BMI树脂－－MBMI／DABPA和MBMI／DA／EP作为研究对象，尝试用PES、PES－C与其共混，以进一步提高韧性，结果表明，液体DABPA和EP在加上可溶解一定量的PES、PES－C树脂，在工艺上实现了用熔融共混法制备增韧BMI树脂，共混少量的PES，能大幅度提高MBI／DA／EP树脂的韧性，且不降低耐热性；而PES与MBMI／DABPA共混，树脂韧性提高，但耐热性有所下降，PES－C与MBMI／DABPA共混则不降低耐热性，共混树脂随热塑性树脂分子链刚性，相容性，分子量及含量的不同呈现不同的相态结构，在PES－C增韧树脂中发现了热固性球粒聚集在热塑性基体中的相反转结构。

Further Reduction of Undesirable Brittleness of Bismaleimide Resins

Abstract: Modified BMI (bismaleimide) resins are much less brittle than unmodified ones, but they are still too brittle for many applications. We now propose to further reduce their brittleness by toughening modified BMI resins with thermoplastics PES (polyethersulfone) and PES-C (polyarylethersulfone with cardo ). For further toughening we select two typical modified BMI systems: MBMI/DA/EP or 4,4'-bismaleimidodiphenylmethane (MBMD/diamine (DA)/epoxy resin (EP); MBMI/DABPA or MBMI/3,3'-diallylbisphenol A (DABPA). In experiments on toughening MBMI/DA/EP and MBMI/DABPA with thermoplastics PES and PES-C, we find that thermoplastics can dissolve in liquid DABPA or EP; so we, for the first time, use melt mixing method in resin preparation. The experimental results, as shown in Tables 1 through 5, show that: (1) addition of a few percent of PES or PES-C can further increase substantially the toughnesses of both MBMI/DA/EP and MBMI/DABPA without lowering their heat resistances; (2) PES of the type of low molecular weight is better than PES-C in toughening effect. The chain rigidity, compatibility, molecular weight and content of thermoplastic affect the morphological structure and phase separation mechanism of the resin and therefore affect the resin's properties. From SEM observations, of which the four photographs in Figs. 1, 2 and 3 are just examples, we discover two different kinds of microstructure and call them two-continuous-phasc structure. The two different kinds of microstructure are: (1) thermoplastic nodules smaller than 1u are dispersed in thermosetting matrix; (2) thermosetting spheres of about 2~10u are concentrated in low proportion thermoplastic continuous phase.