通过原位聚合的方法合成了表面包覆钛酸钡的聚苯胺复合纳米颗粒(BT@PANI),并将该复合纳米颗粒作为填料制备了具有特殊结构的BT@PANI/EP三相复合材料。实验发现由于导电聚苯胺增强了界面极化,因此随着BT@PANI中PANI质量的增加(即BT在复合材料中的质量分数减少),该复合材料的介电常数也随之增加。当PANI的质量分数从0%增加至26%时,其介电常数也从17提高到了53,并且当BT@PANI中PANI的质量分数达到26%时,该复合材料并没有出现明显的渗流效应,且其导电率保持在1.64×10^-6 S/m这一较低值。此外,当测量温度范围在60℃到100℃之间时,该复合材料的介电常数发生了明显的上升,这一现象可以说明随着温度的上升,导电聚苯胺、环氧分子链在Tg温度(90℃)下运动增强及钛酸钡在居里温度(120℃)下的相变共同产生了强烈的界面极化。
Polyaniline deposited BaTiO3 hybrid nanoparticles (BT@PANI) were synthesized via in-situ polymerization process and then used as ifllers to fabricate the BT@PANI/epoxy composites. The dielectric constant of the composites increased with the increment of PANI in BT@PANI(while the fraction of BT decreased in the composite), which was attributed to the enhanced interfacial polarization induced by the conducting PANI. The value of k increased from 17 for 0 wt%PANI to 53 for 26 wt%PANI. No typical percolation effect was observed in the composite and when the content of PANI in the BT@PANIreached 26 wt%, the conductivity maintained a low value of 1.64×10^-6 S/m. Besides, the dielectric constant of the composites jumped remarkably inthe measured temperature range from 60℃to 100℃as anevidenceof the stronger interfacial polarization generated by conducting PANI with temperature increasing, theenhanced motion of epoxy molecule chains around Tg (90℃)and the phase transition of BT near the curie point 120℃.