Title :
TSC study of the polar and free charge peaks of amorphous polymers
Author :
Belana, J. ; Mudarra, M. ; Calaf, J. ; Cañadas, J.C. ; Menéndez, E.
Author_Institution :
Dept. Fisica i Eng. Nucl., E.T.S. de Eng. Ind. de Terrassa, Barcelona, Spain
fDate :
4/1/1993 12:00:00 AM
Abstract :
Electrets of amorphous polyethylene-terephthalate were studied, using thermal windows to polarize and thermally stimulated depolarization current (TSDC) dielectric spectroscopy as an analysis technique. It was found that the polar peak (α) and the free charge peak (ρ) show a maximal area at polarization temperatures, Tp, called the temperature of optimal polarization, Tpo. The Tpo of α is ≈70°C, and for Tp, >Tpo the temperature at which the maximum intensity appears remains constant with Tp. For this range of temperature the intensity of the maximum decreases and the polarization is linear with 1/Tp. The second peak, ρ, which has a Tpo≈87°C, shows the maximum intensity at temperatures that are linear with Tp , Tp>Tpo. For this range of temperatures the intensity of the maximum decreases with T p and the polarization is not linear with 1/T p. These results are compared with those obtained from polyvinylchloride and polymethylmethacrylate
Keywords :
dielectric polarisation; dielectric relaxation; electrets; organic insulating materials; polymers; thermally stimulated currents; TSDC dielectric spectroscopy; amorphous polyethylene-terephthalate; amorphous polymers; dipolar relaxation; electrets; free charge peaks; polar peak; polymethylmethacrylate; polyvinylchloride; temperature of optimal polarization; thermal windows; thermally stimulated depolarization current; Amorphous materials; Dielectrics; Electrets; Electrochemical impedance spectroscopy; Helium; Isothermal processes; Optical polarization; Polymers; Temperature dependence; Temperature distribution;
Journal_Title :
Electrical Insulation, IEEE Transactions on
