NEW POLY(AMIDE-IMIDE) SYNTHESES .3. PREPARATION AND PROPERTIES OF CARDO POLY(AMIDE-IMIDE)S DERIVED FROM 9,9-BIS(4-AMINOPHENYL)FLUORENE, TRIMELLITIC ANHYDRIDE, AND VARIOUS AROMATIC DIAMINES

An imide-ring-containing dicarboxylic acid, N,N'-(9-fluorenylidenedi-1,4-phenylene)diphthalimide-4-carboxylic acid (1), was prepared by condensation of trimellitic anhydride and 9,9-bis(4-aminophenyl)fluorene. A series of new aromatic cardo poly(amide-imide)s having inherent viscosities of 0,59-1,13 dL/g were prepared by the direct polycondensation of this diimide-diacid with various aromatic diamines using triphenyl phosphite and pyridine as condensing agents in 1-methyl-2-pyrrolidone (NMP) in the presence of calcium chloride. The polymers are amorphous and readily soluble in highly polar solvents such as N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, NMP, and m-cresol. Transparent and tough films can be easily cast from the polymer solutions. The glass transition temperatures of these poly(amide-imide)s are above 320-degrees-C. Thermal analyses indicated that these polymers are fairly stable, and the 10% weight loss temperatures were recorded in the range of 532-622-degrees-C in nitrogen atmosphere.