不同偶联剂对聚酰亚胺/六方氮化硼复合薄膜的性能影响

Effects of Coupling Agents on Properties of Polyimide/h-BN Composite Films

采用两种偶联剂对六方氮化硼(h-BN)进行表面改性,并采用原位聚合法制备了一系列聚酰亚胺/六方氮化硼(PI/h-BN)复合薄膜。利用红外光谱仪和激光粒度仪对改性氮化硼(f-BN)的结构和粒度进行测定,使用X-射线衍射仪、扫描电镜、热重分析仪、耐压测试仪及宽频介电谱测试仪等对复合薄膜的结构、热性能及电性能进行了表征。结果表明:加入偶联剂后可改善h-BN在聚合物基体中的分散性,h-BN的加入可以提高复合薄膜的耐热性能和介电常数,但一定程度地降低了复合薄膜的电气强度,从总体改性效果看,硅烷偶联剂的改性效果优于钛酸酯偶联剂。

Hexagonal boron nitride （h-BN） was surface modified by two kinds of coupling agents, and then a series of polyimide/h-BN composite films were prepared by in situ polymerization method. The structure and particle size of the modified BN （f-BN） were measured via infrared spectrometer and laser particle＂ analyzer. The structure, thermal properties and electrical properties were characterized by X-ray diffractometer （XRD）, scanning electron microscope （SEM）, thermogravimetric analyzer, dielectric strength tester, and broadband dielectric spectrometer. The results show that the dispersity of h-BN in the polymer matrix can be improved by coupling agent treatment. The introduction of h-BN improves the heat resistance and dielectric constant of the composite films, but decreases the electric strength of the films. The modified effect of silane coupling agent is better than that of titanate coupling agent.