Thermal conductivity of liquid crystalline epoxy/BN filler composites having ordered network structure

BN filler was added to a liquid crystalline (LC) epoxy resin to obtain a high thermal conductive material. The LC epoxy/BN composites, which were cured at different temperatures, formed an isotropic or LC polydomain phase structure. The relationship between the network orientation containing mesogenic groups and the dispersibility of the BN filler was discussed. As a result, the thermal conductivity of the LC polydomain system was drastically enhanced even at a relatively low volume fraction of BN (30 vol%), regardless of the fact that both the LC and isotropic phase systems consisted of the same resin and filler content combination. This result is due to the formation of thermal conductive paths by the BN filler by exclusion of the BN filler from the LC domain formed during the curing process in the composite having the LC polydomain matrix.