Electret and dielectric properties of electrospun nonwoven polyimides

Electrospun polyimide nonwovens based on the polyamide acid salt of pyromellitic dianhydride (PMDA) and 4,4'-oxydianiline (ODA) with different molar masses were obtained. Their dielectric and electret properties have been studied. It has been established that these materials have a low dielectric constant ($\varepsilon'$ = 1.55–1.91). Charge relaxation of nonwoven polyimides was studied using the method of thermally stimulated depolarization currents. The activation energies of relaxation processes $W$ = 0.81–0.90 eV were calculated using computer simulation.