Electrical properties of polytetrafluoroethylene with mineral fillers under high DC electric field

Electrical conduction properties of PTFE filled with 0.2 wt.% of MoS
₂
are investigated in view of its use in high voltage dc applications. Conduction currents were measured at temperatures from 25°C to 115°C and applied fields up to 60 kV/mm. Volume resistivity has been determined and the conduction mechanisms have been analyzed. After an “ohmic” behavior observed for fields lower than 20 to 30 kV/mm (depending on temperature), the current was found to be controlled by hopping and heterocharge-assisted Schottky injection.