Synthesis and properties of new aromatic noncyclic poly(imide-amide)s fromN,N-bis(aminobenzoyl)anilines and aromatic dicarboxylic acids

Two dianilines containing the noncyclic N-phenylimide group, 4,4′- and 3,4′-diamino-(N,N-dibenzoylaniline), were synthesized as new diamine monomers. The low-temperature solution polycondensation of the diamines with aromatic dicarboxylic acid chlorides afforded poly(imide-amide)s with inherent viscosities of 0.14–0.44 dL/g. The noncyclic N-phenylimide unit in the diamines could be cleaved by nucleophilic attack at the amine function at high temperature. The noncyclic poly(imide-amide)s are soluble in polar solvents such as N,N-dimethylacetamide, N-methyl-2-pyrrolidone, and dimethyl sulfoxide. The polymers have glass transition temperatures and temperatures of 10% weight loss in air in the range of 195–265°C and 405–430°C, respectively.