Poly(amine-amide-imide)s bearing pendent N-carbazolylphenyl moieties: Synthesis and electrochromic properties

[[abstract]]A series of novel poly(amine-amide-imide)s with I pendent N-carbazolylphenyl units that have inherent viscosities of 0.45-0.66 dL.g(-1) are prepared from various aromatic bis(trimellitimide)s and the new carbazole-based aromatic diamine, 4,4-diamino-4 ''-N-carbazolyltriphenylamine, by direct polycondensation. All the polymers are readily soluble in polar organic solvents. Flexible, amorphous, and deep reddish films of poly(amine-amide-imide)s can be obtained by solution casting, and have useful levels of thermal stability associated with high glass transition temperatures (307-343 degrees C), 10% weight-loss temperatures in excess of 500 degrees C, and char yields at 800 degrees C in nitrogen higher than 65%. These polymers exhibit a maximum UV-vis absorption at 300 Inn with a fluorescence emission maxima around 449-454 nm in N-methyl-2-pyrrolidinone solution. The hole-transporting and electrochromic properties are examined by electrochemical and spectroelectrochemical methods. Cyclic voltammograms of the poly(amine-amidei-mide) films cast onto an indium tin oxide-coated glass substrate exhibit a reversible oxidation at 0.84 V and irreversible oxidation redox couples at 1.27 V versus Ag/AgCl in acetonitrile solution, and reveal good stability of electrochromic characteristics, with a color change from yellowish to green at applied potentials ranging from 0.00 to 0.95 V.[[note]]SC