Synthesis and properties of novel poly(amide-imide)s derived from 2,4-diaminotriphenylamine and imide ring-preformed dicarboxylic acids

2,4-diaminotriphenylamine (2) was synthesized via the cesium fluoride-mediated aromatic substitution reaction of 1-fluoro-2,4-dinitrobenzene with diphenylamine,. followed by palladium-catalyzed hydrazine reduction. A series of poly(amideimide)s (PAIs) with inherent viscosities of 0.38-0.46 dL/g were prepared by triphenyl phosphite-activated polycondensation from the diamine monomer 2 with various monoimide- and diimide-dicarboxylic acids. All of the PAIs were readily soluble in a variety of organic solvents and formed strong and tough films via solution casting. These PAIs have moderately high glass transition temperatures in the range of 168-274 degrees C and 10 % weight loss temperatures in excess of 447 degrees C in nitrogen or in air.