PALLADIUM CATALYZED ROUTES TO POLYIMIDES

Several polyimides were prepared by the palladium catalyzed carbonylation and condensation of tetraiodoaromatic compounds and diamines. This new reaction for preparing polyimides was found in model compound work to be an efficient, high yield route to cyclic imides. Since fully imidized groups are formed during the polymerization, it was necessary to limit the diamines to those that would impart solubility to the polymer. In contrast to the model compound work, the polymerization reaction yielded an appreciable concentration of amide functional groups due to incomplete cyclization and/or branching reactions. Mixed haloaromatic compounds were also examined as monomers in this reaction. Model reactions between omicron-bromoiodobenzene and aniline indicated that amide formation through the iodide was preferred and that imide formation through the bromide occurred later. Extension of this chemistry to dibromodiiodobenzene and diaminophenylindane DPI, gave low molecular weight oligomers at low phosphine levels and branched material at higher levels.