Low-Cost Preparation of High-k Expanded Graphite/Carbon Nanotube/Cyanate Ester Composites with Low Dielectric Loss and Low Percolation Threshold
Lei Cao , Wei Zhang , Xinhua Zhang , Li Yuan , Guozheng Liang *(梁国正), and Aijuan Gu *（顾嫒娟）
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, Jiangsu 215123, China
Ind. Eng. Chem. Res. 2014, 53, 2661–2672
Expanded graphites (EGs) or modified EGs (eEGs) were blended with multiwalled carbon nanotubes (MWCNTs) in a big weight ratio to prepare low-cost composites, coded as (EG-MWCNT)/cyanate ester (CE) or (eEG-MWCNT)/CE. The structures and properties of the composites are closely related to the loading of total conductors (f). When f < 0.75 wt %, EGs are beneficial for preparing high-k composites with low dielectric loss; however, when f ≥ 1.05 wt %, eEGs have superior advantages. When f = 1.5 wt %, the dielectric constant and loss of (eEG-MWCNT)1.5/CE composite are about 1.6 and 0.6 times that of the (EG-MWCNT)1.5/CE composite, respectively. The origin behind these interesting results was intensively discussed. Attractively, (EG-MWCNT)/CE and (eEG-MWCNT)/CE composites have similar percolation thresholds, so the surface modification of EGs does not increase the percolation threshold; moreover, ternary composites prepared herein have much better dielectric properties than both traditional EG/CE and MWCNT/CE composites.
链接： //pubs.acs.org/doi/abs/10.1021/ie402832u
