Thermal Conductivity of Compositions Based on a Siloxane Binder With a High Filler Content of Aluminum Hydroxide Powder

Abstract

The use of aluminum hydroxide as a filler in composite materials makes them non-flammable. When the thermal conductivity of such compositions is above 1 W/(m-K), they can be used as heat-conducting insulating and non-flammable coatings in power electronics. Thermal conductivity of compositions based on dimethylsiloxane with a filler made from aluminum hydroxide powders of various dissipation is studied in the temperature range from 25 °C to 200 °C, depending on the volume content of the filler. With a volumetric content of filler up to 60%, no significant differences in the values of the thermal conductivity of samples with powders of the investigated fractional groups were detected. With volumetric content of the filler more than 40%, the thermal conductivity of the composition at room temperature exceeded 1 W/(m-K). It is shown that the Burger formula modified by the authors turned out to be sufficiently universal for the calculated estimates of the thermal conductivity of materials with different fillers in a wide range of their volume contents.