SYNTHESIS AND CHARACTERIZATION OF ORGANO-SOLUBLE, THERMALLY-CURABLE, PHENYLATED AROMATIC POLYIMIDES.

Abstract

High-molecular-weight polyimides that are soluble in common organic solvents can be prepared by the polymerization of phenylated bis(phthalic anhydrides) with aromatic diamines. These phenylated polymers display excellent thermal stability and can be cast into thin flexible films. Their Tg's can be varied from 238 to 466 degree C by using different diamine and dianhydride combinations. Thermal crosslinkability can be built into these systems through the use of diamines containing ethynyl and phenylethynyl moieties. Material costs can be reduced by replacing up to 50 mole percent of the phenylated dianhydride with PMDA.