A soluble and electroactive polyaniline obtained by coupling of 4-sulfobenzenediazonium ion and poly (N-methylaniline)

A modified polyaniline was obtained by coupling of the 4-sulfobenzenediazonium ion with poly (N-methylaniline) (PNMANI) at temperatures below 5°C and in basic or neutral pH conditions. The FT-IR spectra of the product show all bands due to the poly(N-methylaniline). Additional bands at 1007, 1003 and 623 cm−1 are assigned to the vibrations of the sulfonate group, incorporated in the polymer matrix. A new band at 1485 cm−1 is also present, assigned to the stretching of the azo bond. The polymer is soluble in aqueous base. The results suggest the formation of an azo-substituted poly (N-methylaniline): poly(4-sulfobenzenazo-(N-methylaniline)) (p(4SBA-NMANI)). The solution spectra show absorption bands at 242, 310 and 595 nm. Thin films deposited on glassy carbon show clear electroactivity. The method could be used to produce electroactive films with bonded functionalities.