Dielectric relaxation in polymers with particular reference to two‐phase systems

Dielectric relaxation is introduced as the response of charged species to a change in the electric field applied to a sample. In the case of polymeric materials two important processes are orientation of segment dipoles and limited migration of charge carriers. Two areas where new advances of technical importance are being made are discussed: dielectric processes at very high frequencies which might be encountered when plastic materials are used in communication and dielectric waveguides, and interfacial polarizations encountered in two phase systems. These latter may be used to create devices of high permittivity and are also responsible for deterioration in the performance of many electrical‐grade laminates.