Title :
Influence of physical aging processes on electrical properties of polymers
Author :
Yianakopoulos, G. ; Vanderschueren, J. ; Niezette, G.
Author_Institution :
Dept. of Macromolecular & Phys. Chem., Liege Univ., Belgium
Abstract :
The influence of aging temperature and time on the electrical properties of amorphous polydiancarbonate (PC) and poly(methyl methacrylate) (PMMA) was investigated using the techniques of thermally stimulated depolarization currents, transient currents, and AC dielectric losses. It is shown that in the temperature range located between the α relaxation (glass transition) and the secondary β relaxation, the polarization and loss properties of amorphous polymers undergo pronounced changes during physical aging. A progressive decrease in molecular mobility (and corresponding increase in relaxation times) leads to a marked decrease in polarization and dielectric losses as a function of aging time, showing that physical aging is a general phenomenon which should not be ignored in any testing of electrical properties of plastics
Keywords :
ageing; dielectric losses; dielectric polarisation; dielectric properties of solids; environmental degradation; insulation testing; organic insulating materials; polymers; thermally stimulated currents; transients; α relaxation; AC dielectric losses; ageing time; amorphous polymers; electrical properties; molecular mobility; physical ageing processes influence; polarization; poly(methyl methacrylate); polydiancarbonate; secondary β relaxation; thermally stimulated depolarization currents; transient currents; Aging; Control systems; Dielectric losses; Glass; Mechanical factors; Nitrogen; Polarization; Polymers; Temperature distribution; Vitrification;
Conference_Titel :
Conduction and Breakdown in Solid Dielectrics, 1989., Proceedings of the 3rd International Conference on
Conference_Location :
Trondheim
DOI :
10.1109/ICSD.1989.69188
