Thermally stimulated discharge of polymer electrets: A study on nonisothermal dielectric relaxation phenomena

It is a well-established truth that an action causes a reaction. The reaction, however, need not occur instantaneously. Examples of delayed responses to stimuli are numerous in several fields of human experience. The best known, in the field of physics, are mechanical and dielectric relaxation phenomena. This thesis is devoted to a study of the nonisothermal dielectric relaxation behaviour of polymers. These exhibit a spectacular relaxation phenomenon, since they can be permanently charged by exposing them to a field-temperature treatment. Polymers or rather dielectrics, bearing a persistent charge are called electrets. Carrying opposite charges on two sides, electrets are the analogues of magnets. It has been our aim to clarify, theoretically and experimentally, the mechanisms responsible for the decay of their frozen-in charge.