Study of dielectric behavior of aromatic polyimide films

Aromatic polyimide films were prepared and their dielectric constant and relaxation behavior were studied. Polyimide films have good insulating properties with dielectric constant values in the range of 2.88 - 3.48 at 1Hz and room temperature. Three relaxation processes (γ, β
₁
and β
₂
) at sub-glass temperatures were observed and investigated. The cooperativity of the molecular motions associated with the relaxation processes was discussed.