Effect of arrangement of nano and micro barium titanate (BaTiO₃) particles on the enhanced dielectric constant of high-density polyethylene (HDPE)/BaTiO₃

The aim of this study is to improve the dielectric and mechanical properties of HDPE/BaTiO₃ composites by binary BaTiO₃ particles, when the volume fraction of BaTiO₃ is constant. In this study, it was found that the pack density of binary BaTiO₃ particles in HDPE/BaTiO₃ composite relies on particle ratio and volume fraction of small particles. It is found that the addition of 50 vol % 1600 nm BaTiO₃ particles can boost the dielectric constant of HDPE control from 2 to 30 (14 times higher) at 40 Hz and 19 (8.5 times higher) at 40 MHz, respectively. When the particle ratio was 4, the substitution of 10 vol % 1600 nm BaTiO₃ particles by 10 vol % 400 nm BaTiO₃ particles can further enhance the dielectric constant of HDPE/L-BT (10/10) from 30 to 50 (67% increase) at 40 Hz and from 19 to 42 (121% increase) at 40 MHz, respectively, without greatly influencing the volume resistivity of HDPE composites. In addition, the thermal conductivity of HDPE with binary BaTiO₃ particles were all above 2.0 W/(m•K).