Effect of BaTiO₃ Size on Dielectric Performance of Ultraviolet-Cured Epoxy Acrylic Composites with BaTiO₃

It has been reported that the size of barium titanate (BaTiO₃, BT) fillers plays an important part in the dielectric properties of the dielectric composites using polymer as a matrix and BT ceramics powders as fillers. However, BT nanoparticles are usually used as fillers. In addition, compared with conventional hot-pressing technology, UV-curing technology has many advantages, such as high efficiency, energy saving and environmental protection. In this paper, composites containing epoxy acrylic (EA) as a matrix and BT powders with various diameters of 3 μm, 0.5 μm and 60 nm as fillers are manufactured by using the UV-curing technique. The influence of BT size on the dielectric performance of BT/EA composites is investigated. BT(0.5 μm)/EA composites show the highest dielectric permittivity, which is 24.10 with a BT fraction of 25% at 50 Hz. BT(3 μm)/EA composites show the lowest dielectric loss tangent, which is 0.114 with a BT fraction of 25% at 50 Hz. BT(0.5 μm)/EA composites possess the highest breakdown strength, the α value of which is 147 when the BT fraction is 25%. In conclusion, by adjusting the BT size and filling degree, BT/EA composites can be prepared with the expected dielectric parameters.