ELECTROPHYSICAL PROPERTIES OF POLYIMIDE MATERIALS AND POLYIMIDE-BASED COMPOSITES

This work investigates the electrophysical properties of thermoplastic and thermosetting polyimides (PI): electrical conductivity, dielectric strength, dynamic mechanical characteristics. In order to increase the dielectric strength, composite materials based on polyimide matrices are synthesized. The glass transition temperatures Tg for PI are determined by the dynamic mechanical analysis. With an increase in Tg, an increase in the modulus of elasticity and a decrease in the tangent of the mechanical losses are observed. In the temperature range below the glass transition temperature, the conductivity of PI does not depend on the flexibility of the macromolecule chain. The dielectric strength of PI at alternating voltage of industrial frequency (50 Hz) is determined. Compared to the Ultem film, the breakdown voltage of the domestic R-BAPS film is higher by 24%. At the same time, the introduction of fillers (Aerosil, fluoroplast) into R-BAPS and PMDA-ODA did not lead to an increase in the dielectric strength.