Structural modification of carbon black for improving the dielectric performance of epoxy based composites

Abstract

To explore a feasible strategy for improving the dielectric properties of carbon black (CB)/epoxy composites, CB@TiO2 core-shell particles and CB-SiO2 hybrid particles were prepared and incorporated into epoxy. The microstructures of CB, CB@TiO2, and CB-SiO2 particles, as well as the dielectric properties of their epoxy-based composites were investigated. The results showed that the composites containing CB-SiO2 hybrid particles possessed a higher dielectric constant than the ones containing pristine CB. The dielectric constant of the composite with 20.0 vol% CB-SiO2 reached 52.68 (1 kHz), which was ca. 4 times greater than that of the one containing 20.0 vol% pristine CB. Meanwhile, the composites containing CB@TiO2 core-shell particles exhibited suppressed values of dielectric loss. The permittivity of the composite with 20.0 vol% CB@TiO2 reached 19.52 (1 kHz), while its dielectric loss remained low (0.047 at 1 kHz). These results indicated that the dielectric properties of epoxy composites could be enhanced with the introduction of modified fillers. Keywords: Carbon black, Epoxy, Composite, Dielectric performance