Dielectric properties of PI/BaTiO3 with disparate inorganic content

Polymer-ceramic dielectric composites have been interesting because they combine the processability of polymers with the desired dielectric properties of the ceramics. Barium titanate/polyimide (BaTiO₃/PI) nanocomposite films with high permittivity are prepared by an in-situ polymerization process in this paper. While the mixture contained 70wt% nanosized BT fillers, permittivity of composite film was up to 15.1. In the meantime, the composite possessed the high AC breakdown strength (41MV/m). To be accompanied by the increasing of permittivity, however, other electrical properties of composite materials degenerated slightly, such as dielectric loss and breakdown field strength. The structure of nanoparticles and composites were investigated by means of SEM. The results indicated that barium titanate particles can homogeneously disperse in the PI matrix. A series of composite with high dielectric constant and insulating property were discussed for various filler mass contents.