ABSTRACT
Solid insulating materials are encountered in every electric and electronic device and piece of equipment, both large and small. They are vital for isolating conductors and for their proper performance. This chapter discusses the important electrical, physical, and chemical properties common for solid insulating materials. It briefly describes the theories of their electrical breakdown, some of the most widely used. These electrical properties are essentially the dielectric constant, electrical resistivity, and dielectric strength of the material. The dielectric constant is determined by the phenomenon of polarization that takes place inside the material when under an electric field. The effect of temperature on the permittivity and polarization of nonpolar dielectrics is negligible. The process of breakdown of solid dielectrics is much more complex than that of gases, for example. Intrinsic breakdown occurs purely due to the electronic behavior of the dielectric, with no effect of ambient or temperature rise.
