A Study on the Dielectric Properties of EVA/Carbon Black Composites

EVA/카본블랙 복합체의 유전특성에 관한 연구

To measure electrical properties of semiconducting materials in power cable, we have investigated dielectric properties of EVA showed by changing the content of carbon black. The specimen was primarily kneaded in material samples of pellet form for 5 minutes on rollers ringing between $70[^{\circ}C]$ and $100[^{\circ}C]$. Then that was produced as sheets after pressing for 20 minutes at $180[^{\circ}C]$ with a pressure of 200[kg/cm]. The contents of conductive carbon black were 20, 30 and 40(wt%), respectively The dielectric properties of specimens were measured by dielectric thermal analyzer (CONCEPT 40, NOVOCONTROL). Measuring frequencies were 10, 60, 100, 1000, 10000, 100000, 1000000(Hz) and measuring temperatures were -40, -20, 20, $90[^{\circ}C]$. From above experimental result, permittivity was increased, while $tan{\delta}$ was decreased according to an increment of the content of carbon black.