Synthesis and characterization of new azobenzenesulfonic acids doped conducting polyaniline

New azobenzene sulfonic acid dopants were synthesized by diazotized coupling reaction of sulphanilic acid diazonium salt with commercially available raw materials such as phenol, m-cresol and 4-phenylphenol. The structures of the dopants are confirmed by NMR and FT-IR. Polyaniline emeraldine base was doped by these new azobenzenesulfonic acid dopants in two different solvent medium such as methanol and N-methylpyrrolidinone to produce green emeraldine salt. The doping process was confirmed by FT-IR and UV-vis spectroscopy. The effect of composition of dopant on the conductivity of the polyaniline was investigated and the results suggest that the conductivity increases with the increase in the dopant concentration and attained maxima for more than 38% in the feed. The conductivity measurements reveal that all the dopants equally effective in producing in high conductivity in the range of 0.02 S/cm and the conductivity of the doped samples are insignificant to the structural difference in the dopant. WXRD and SEM analysis indicate that the doped samples are highly amorphous and porous in nature. The thermal analysis by TGA indicate that all the doped materials were highly stable up to 300 degrees C for high temperature applications. (c) 2006 Elsevier Ltd. All rights reserved.