Dielectric Characteristics of Thermoplastic Polyimide R-BAPS and R-BAPB Films in the Low Frequency Range

The results of the investigation dielectric characteristics of thermoplastic polyimide R-BAPB and R-BAPS films are presented. The absorption charging currents Ich(t) of R-BAPB & R-BAPS TPI films ranging the temperature in between 20 °C- 200 °C for 5 hours in constant electric field 2·105 V/m. The experimental data were analyzed to correspond to Voigt equivalent and Maxwell's circuits. Main dielectric characteristics [permittivity ε'(ω), dielectric loss(tan δ), dielectric loss factor ε"(ω), active Za(ω) and reactive Zc(ω) resistances] were computed and compared in the range of frequencies from 10-4 to 10-1 Hz according to the parameters of Voigt's and Maxwell's equivalent scheme. The mechanisms of charge accumulation of R-BAPB and R-BAPS films within constant electric field were analyzed.