以聚苯胺表面包覆钛酸钡作为填料的环氧复合材料的微观结构与介电性能(英文)

Microstructure and Dielectric Properties of Epoxy Composites with Polyaniline-Deposited Ba TiO_3 as Fillers

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＆amp;nbsp;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℃.