Dielectric properties of a high molecular weight high fire point liquid dielectric

Dielectric properties of a high molecular weight high fire point liguid dielectric have been measured over the temperature range −50°C to 175°C. The properties of interest are the relative dielectric consant ε
r
, tanδ, the dielectric strength and the conduction current. At low freguencies ε
r
decreases steadily with increasing temperature over the entire temperature range. Tanδ remains constant at a very small value, 5 × 10
⁻⁶
up to 55°C and for higher temperatures increases rapidly reaching 3.8 × 10
⁻²
at 175°C. At room temperature the withstand voltage is 300 kV cm
⁻¹
for a 2 mm gap decreasing to 255 kV cm
⁻¹
at 100°C, and then increasing again to 275 kV cm
⁻¹
at 125°C.