Dependence of dielectric properties on BT particle size in EP/BT composites

摘要

The polymer-ceramic composites of epoxy resin (EP) and barium titanate (BT) were prepared. BT powders of different BT particle sizes from 100 nm to 1 μm were used in the preparation. The dielectric properties, such as dielectric constant, dielectric loss and electrical breakdown strength, of the EP/BT composites were studied. The morphology of the composites was characterized by the means of scanning electron microscopy (SEM) . The results show that the dielectric constant of the composites is much higher than the epoxy matrix at frequency range from 1 kHz to 10 MHz, and it is also obviously dependent on the size of BT particles . The electrical breakdown strength of the composites decreases with the increase of the BT content. The dependence of electrical breakdown strength on BT particle sizes was also discussed.