Absorption Properties of Polyimide Films with Various Macromolecular Rigidity

This work focuses on the effect of macromolecular rigidity on the absorption characteristics of polyimide (PI) films. The absorption currents were measured for 4 hours in a broad temperature range (from 25 to 175 °C). The temperature dependences and activation energies of conductivity for PI films with different macromolecular rigidity were achieved. The experimental data were analyzed to determine Voigt equivalent circuits’ parameters. Using these parameters, dielectric permittivity, dielectric loss factor and absorption coefficient were calculated and compared for PI films in a low frequency range.