NOVEL POLYIMIDES CONTAINING ALICYCLIC UNITS. SYNTHESIS AND CHARACTERIZATION

A series of novel polyimides containing alicyclic moieties have been synthesized. These polyimides were prepared by high-temperature polycondensation of an alicyclic dianhydride, 5-(2,5-dioxotetrahydro-3-furanyl)-3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride (Epic Ion) with two diamines, 4,4'-methylenedianiline (DDM) and 1,6-hexamethylenediamine (HMDA). Polycondensation reactions proceeded at 185 degrees C and produced imide type polymers with high thermal stability. All the polymers had good solubility toward polar solvents, were stable up to 345 degrees C with 5% weight loss and had glass transition temperatures in the range of 122-235 degrees C. The polyimides formed flexible films and showed high transmission above 80% in the wavelength of 400 - 700nm. The correlation between the polymers structure and their properties has been discussed.