Dielectric properties of polymers

Traditional dielectric materials have long been inorganic insulating substances (silica, alumina, etc.), but organic polymers are increasingly used because of their processing possibilities (films, laminates, moldings, etc.), flexibility, low density and wide range of compositions, enabling them to be adapted to specific needs. Main applications include capacitor films, cable and connector insulation, supports and substrates for printed circuit boards and antennas, and encapsulation materials for electronic components.

The aim of this article is to present the advantages and limitations of polymeric dielectric materials and the various strategies for optimizing them for these specific applications.

This article presents some theoretical elements of the dielectric properties of materials (permittivity and loss factor) and details the polarization phenomena specific to macromolecular materials. It shows the role of their physico-chemical structure on these properties, as well as the influence of frequency and temperature on their variation. Other important parameters for electrical and electronic applications (resistivity, dielectric strength, environmental stability) are also covered.

Finally, the main applications are presented, along with the most widely used dielectric polymers for each of them.