Modeling of dielectric relaxation spectra of polymers in the condensed phase

Discusses models and their possible implication in the interpretation of the relaxation spectra of polymers, particularly involving the concept of order/disorder systems. Furthermore, some examples of the application of the Dissado-Hill model have been provided in this work to explain quasi-dc (QDC) conduction processes, which have been observed in crosslinked polyethylene (XLPE) and low density polyethylene (LDPE), showing an ageing behavior with continuing use with an ac field in a humid environment. It is also shown in this paper how a measurement of dielectric relaxation properties on a wide frequency range may be used as a tool to investigate the ageing of polymeric power distribution cables with an ac field in a humid environment. Equivalent electrical analog circuits of dielectric relaxation spectra are also shown.