Influence of aging on electrical properties of polyethylene naphthalate-2,6 dicarboxylate films

Poly(ethylene naphthalate 2,6 dicarboxylate), thanks to its heat resistance, may be used as insulating material in motors and laminated chip capacitors. In these specific applications the occurrence of partial or corona discharges leads to insulation aging and possible breakdown. An experimental investigation has been carried out to determine the changes in dielectric properties as function of the aging conditions, e.g. the temperature of irradiation. Dielectric loss values have been determined in the 10/sup 2/ to 10/sup 6/ Hz frequency range from 150 to 200/spl deg/C. Three relaxation peaks were found /spl alpha/,/spl beta/*,/spl beta/, in the order of decreasing temperature.