Thermal and Dielectric Properties of the Aluminum Particle/Epoxy Resin Composites

Microsized aluminum/epoxy resin composites were prepared, and the thermal and dielectric properties of the composites were investigated in terms of composition, aluminum particle sizes, frequency, and temperature. The results showed that the introduction of aluminum particles to the composites hardly influenced the thermal stability behavior, and decreased T of the epoxy resin; moreover, the size, concentration, and surface modification of aluminum particles had an effect on their thermal conductivity and dielectric properties. The dielectric permittivity increased smoothly with a rise of aluminum particle content, as well as with a decrease in frequency at high loading with aluminum particles. While the dissipation factor value increased slightly with an increase in frequency, it still remained at a low level. The dielectric permittivity and loss increased with temperature, owing to the segmental mobility of the polymer molecules. We found that the aluminum/epoxy composite containing 48 vol % aluminum-particle content possessed a high thermal conductivity and a high dielectric permittivity, but a low loss factor, a low electric conductivity, and a higher breakdown voltage. (C) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 118: 3156-3166, 2010