Epoxy-based high-k composites with low dielectric loss caused by reactive core-shell-structured carbon nanotube hybrids

Polymer composites with a high dielectric constant (high-k) and low dielectric loss represent an important research topic for the rapid development of electronic industries. This paper reports on a type of high-k composite with low dielectric loss (dielectric constant is approximately 152, and dielectric loss is only 0.06 at 10 kHz) through a compounded epoxy resin with homemade core-shell-structured carbon nanotube (CNT) hybrids. The composite is prepared by in situ controlled free-radical copolymerization of divinylbenzene and glycidyl methacrylate on the surface of CNTs. The reactive shell contained epoxy groups that play a dual role in keeping the low dielectric loss of the composites and high dispersibility of the coated CNTs. The coated CNTs with proper thickness (about 30 nm) and epoxy value (0.011 mol/g) were selected to prepare the composites.