Low dielectric constant polyimides containing alicyclic segments

New polyimides have been synthesized by reaction of 3,3´,4,4´-benzophenone tetracarboxylic dianhydride (BTDA) or/and 5-[2,5-(dioxotetrahydrofuryl)]-3-methyl-3-cyclohexen-1,2-dicarboxylic anhydride (DOCDA) with 4,4´-methylene dianiline (DDM). Polycondensation reactions were carried out in solution and resulting polyimides gave flexible free-standing films. The introduction of alicyclic moieties in the polyimide backbone improved their solubility, giving thermally stable films. The relative dielectric constant values was in range of 3.16-2.86 measured at 1kHz and room temperature, and decreased with increasing of the alicyclic units content.