Electrical resistivity or conductivity measures how strongly it resists to electric current.
The electrical properties of polyurethane elastomers most commonly measured are as follows:
Resistivity
Dielectric Strength
Dielectric Constant
Power Factor
Materials suitable for electrical insulators have high dielectric strength and resistivity and low dielectric constant and power factor. Such a combination is rarely obtained since companion physical and chemical properties are also required. There is no single best overall material however polyurethane offers a favorable combination of properties.
Direct Current Resistivity
Direct current resistivity, or volume resistivity, is similar to insulation resistance in that both indicate the magnitude of electrical current expected to pass through the sample located between two electrodes. This test may be used to check the suitability of an elastomeric composition for electrical insulation.
Resistivity or specific resistance to electric current is usually considered to be a DC property and is measured as such. It can be defined as the resistance between opposite faces of a unit cube where precautions have been taken to allow no current flow along the other four faces of the cube.
Conductivity
Elastomeric compositions are considered electrically conductive when they possess a direct current resistivity of less than 10^5 to 10^7 ohm-cm. Conductive compounds find their principal application where the dissipation of static electricity is desired.
