Synthesis and Properties of New Aromatic Polyamides with Redox-Active

ABSTRACT: A new triphenylamine-based diamine monomer, 4,40-diamino-200,400-dimethoxytriphenylamine (2), was synthesized from readily available reagents and was reacted with various aro-matic dicarboxylic acids to produce a series of aromatic poly-amides (4a–h) containing the redox-active 2,4-dimethoxy-substituted triphenylamine (dimethoxyTPA) unit. All the resulting polyamides were readily soluble in polar organic solvents and could be solution cast into tough and flexible films. These poly-mers exhibited good thermal stability with glass transition temper-atures of 243–289 C and softening temperatures of 238–280 C, 10 % weight loss temperatures in excess of 470 C in nitrogen, and char yields higher than 60 % at 800 C in nitrogen. The redox behav-iors of the polymers were examined using cyclic voltammetry (CV). All these polyamides showed two reversible oxidation pro-cesses in the first CV scan. The polymers also displayed low ioniza-tion potentials as a result of their dimethoxyTPA moieties. In addition, the polymers displayed excellent stability of electrochro-mic characteristics with coloration change from a colorless neutral state to green and blue-purple oxidized states. These anodically coloring polyamides showed high green coloration efficiency (CE 329 cm2/C), high contrast of optical transmittance change (DT % 84 % at 829 nm), and long-term redox reversibility. VC 201