Effect of acrylic copolymer dispersants bearing epoxy groups on rheological and dielectric properties of carbon black-filled epoxy system

In this article, the use of copolymeric dispersants with an acrylic backbone and epoxy side groups for formulating carbon black (CB)-epoxy composites are described. Six epoxy-containing acrylic copolymer dispersants were prepared from hexyl methacrylate (HMA), poly(ethylene glycol) ethyl ether methacrylate (PEGMA), and glycidyl methacrylate via a group transfer polymerization technique. The epoxy-containing acrylic copolymer of the highest concentration of PEGMA showed a desirable passivation effect on CB, and was found to lower the viscosity of the CB-epoxy paste, leading to the well-cured composite after heat treatment. The thick composite film prepared by employing the [CB/acrylic dispersant/epoxy] paste was built up on a Cu plate by a screen printing process followed by thermal curing. The dielectric properties of the 3.1 vol % CB-filled epoxy film showed us high dielectric constant (Dk 4900) and rather low dissipation factor (Df 29%) at 1 MHz. (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012