磷酸铝表面修饰及增强双马来酰亚胺复合材料性能

Surfacial modification of aluminum phosphate and reinforced bismaleimide resin composites

摘要:

界面行为是决定聚合物基复合材料性能的重要因素之一。首先采用硅烷偶联剂和顺丁烯二酸酐对层状磷酸铝（LAP）逐步修饰制备出表面修饰LAP（m-LAP）；其次利用2，2'-二烯丙基双酚A（DABPA）扩链改性4，4'-双马来酰亚胺基二苯甲烷（BDM）得到双马来酰亚胺（BMI）树脂预聚体；最终利用机械共混法和热固化工艺制备了m-LAP/BMI复合材料。研究发现，m-LAP与BMI基体之间形成了连续、紧密、低缺陷的界面结合。与纯BMI相比，m-LAP/BMI-3.5复合材料的常温弯曲强度为173.37MPa，提高了15.14%；经300℃热处理6h后，m-LAP/BMI-3.5复合材料弯曲强度仍能保持常温强度的71.22%，远高于热处理后的纯BMI树脂及LAP/BMI复合材料；m-LAP/BMI复合材料的玻璃化转变温度（Tg）提高至234~240℃；m-LAP/BMI-3.5复合材料的介电常数达到4.46，介电损耗为0.05。因此，两步表面修饰法能够显著改善LAP/BMI复合材料的综合性能。

Abstract:

Interfacial interaction is an important factor determining the properties of polymer composites. Firstly, ultilized two-step reactions of silane coupling agent and maleic anhydride, the surface modification of layered aluminum phosphate (LAP) was prepared; then chain extended bismaleimide (BMI) resin prepolymer was obtained by 4, 4' -bismaleimide diphenylmethane (BDM) and 2, 2' -diallylbisphenol A (DABPA) reaction; finally, LAP/BMI composites was successfully prepared by mechanical blending and thermal curing. It was found that continuous, tight and low-defect interface binding was formed between modified LAP (m-LAP) particles and BMI matrix. Compared with pure BMI, the bending and tensile strength of m-LAP/BMI-3.5% composites at room temperature are 173.37 MPa and 86.79 MPa, which are increased by 15.14 % and 30.6 %, respectively. After heat treatment at 300 ℃ for 6 h, the bending strength of m-LAP/BMI-3.5 composites can still maintain 71.22 % of the normal temperature strength, which is much higher than that of pure BMI resin after heat treatment. The glass transition temperature (Tg) of m-LAP/BMI composites was increased to 234~240 ℃. The dielectric constant and dielectric loss of m-LAP/BMI-3.5 composite are 4.46 and 0.05 respectively. Therefore, the two-step surface modification can significantly improve the overall properties of LAP/BMI composites.