Preparation of End-Capped Hyperbranched Polyaniline@Carbon Nanotube Hybrids for High-k Composites with Extremely Low Percolation Threshold and Dielectric Loss
Zhixiang Qiang , Guozheng Liang *(梁国正), Aijuan Gu *（顾嫒娟）, and Li Yuan
Jiangsu Key Laboratory of Advanced Functional Polymer Design and Application, Department of Materials Science and Engineering, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, China
Ind. Eng. Chem. Res. 2014, 53, 4726–4731
How to greatly decrease the dielectric loss while maintaining extremely low percolation threshold (fc) is the main target of developing high-k conductor/polymer composites. Here, novel hybridized multiwalled carbon nanotubes (MWCNTs) with coated end-capped hyperbranched polyaniline (EHSiPA), EHSiPA@MWCNT, were developed and embodied into epoxy (EP) resin to produce new high-k composites. Systematic investigations of the structure and dielectric properties showed that the fc of EHSiPA@MWCNT/EP composites is as low as 0.41 wt %; in addition, EHSiPA@MWCNT/EP composites with suitable loadings of EHSiPA have much higher dielectric constants and lower dielectric losses than the MWCNT/EP composite. Specifically, the dielectric constant and loss at 100 Hz for EHSiPA3@MWCNT0.4/EP are 1.4 and 6.8 × 10–3 times the values for the MWCNT0.4/EP composite, respectively. To reveal the origin of this, the distributions of space charges of EHSiPA@MWCNT/EP composites are discussed. This investigation suggests that designing and preparing new conductors with unique structures may provide a way to fabricate high-k composites.
链接：//pubs.acs.org/doi/abs/10.1021/ie404419p
