Effect of the Ceramic Particle Size on the Microstructure and Dielectric Properties of Barium Titanate/Polystyrene Composites

Excellent dielectric properties are a key factor for the technology of capacitors. Some ceramics, such as barium titanate (BaTiO3 or BT), have high dielectric constants, although they are hard to process. Polymers that often display low dielectric permittivities are easy to fabricate into all kinds of shapes. So the preparation of one composite material consisting of polymer and ceramic particles may be an excellent solution for satisfying the processing requirements. In this Study, fresh polystyrene (PS) was synthesized and Subsequently used to prepare BT/PS composites with a ball-grinding mixture technology. The microstructure and dielectric properties of the BT/PS composites at different frequencies and different temperatures were studied. The results Show that the dielectric permittivities of the composites with BT with a particle diameter of approximately 700 nm (BT-07) were obviously higher than those of the composites with BT with a particle diameter of approximately 100 nm (BT-01) at the same concentration of BT. Moreover, the dielectric permittivities of the composites with BT-01 displayed better stabilization than those made with BT-07 at the different temperatures. (C) 2008 Wiley Periodicals, Inc. J Appl Polym Sci 110: 3473-3479, 2008