Dielectric Properties of Polyimide Film. I. Ac Properties

Dielectric properties have been measured, in the frequency range 100 to 100 kHz and in the temperature range -200 to +150°C, for as-received polyimide and for polyimide annealed at 240°C/24 hr. Three loss peaks were found. The structural motions which give rise to these peaks have been determined through a comparison with other data on polyimide, as well as with data on the structurally simi lar polyamides and polyurethanes.