Uniformly dispersed submicrometric BaTiO3 particles in HDPE based composites morphology, structure and dielectric properties

The use of nanofillers to induce certain changes in electrical properties of polymeric materials, show great interest for electronic and electrical engineering applications. In this paper, composites of HDPE filled with submicrometric particles of tetragonal BaTiO₃ have been prepared. An extraordinary uniform dispersion of the particles was achieved from a first process of mixing by high energy ball milling and subsequent hot pressing. Some electric measurements such as dielectric strength and resistivity were carried out to evaluate the final electrical properties as a function of the processing and the amount of BaTiO₃ particles. It was observed how the resistivity decreases when the amount of BaTiO₃ increases. Besides, the dielectric strength decreases as the amount of BaTiO₃ particles increases. Finally it was observed that as the BaTiO₃ content increases the cylindrical-like “conducting channel”, in which the dielectric failure happens, disappears, occurring a dielectric breakdown with a less regular shape.