NEW POLY(AMIDE-IMIDE)S SYNTHESES .2. SOLUBLE POLY(AMIDE-IMIDE)S DERIVED FROM 2,5-BIS(4-AMINOPHENYL)-3,4-DIPHENYLTHIOPHENE AND VARIOUS N-(OMEGA-CARBOXYALKYL)-TRIMELLITIMIDES, N-(CARBOXYPHENYL)TRIMELLITIMIDES, OR N,N'-BIS(OMEGA-CARBOXYALKYL)PYROMELLITIMIDES

Various dicarboxylic acids with preformed imide rings were readily obtained by the condensation of omega-amino acids and aminobenzoic acids with trimellitic anhydride, and omega-amino acids with pyromellitic dianhydride. New tetraphenylthiophene-containing poly(amide-imide)s having inherent viscosities of 0.58-1.54 dL/g were prepared by the direct polycondensation reaction of 2,5-bis(4-aminophenyl)-3,4-diphenylthiophene with the imide-containing dicarboxylic acids using triphenyl phosphite and pyridine as condensing agents. These polymers were amorphous and readily soluble in a variety of solvents such as dimethylacetamide (DMAc), dimethylformamide (DMF), and N-methyl-2-pyrrolidone (NMP), and could be easily solution cast into transparent, flexible, and tough films. Most of the poly (amide-imide) s showed clear glass transition on the heating traces of differential scanning calorimetry (DSC) in the range of 146-244-degrees-C. Almost all the poly (amide-imide) s exhibited no appreciable decomposition below 400-degrees-C, with 10% weight loss being recorded above 420-degrees-C in nitrogen.