Degradation behavior of polyanilines with different modes of doping

Abstract

The degradation behavior of three different types of polyaniline salts: (i) polyaniline externally protonated by HClO4 or metanilic acid, (ii) self-doped polyaniline by sulfonation of emeraldine base, and (iii) co-polymers of metanilic acid and aniline possessing simultaneous self-doping and external doping by either HClO4 or metanilic acid, are compared under heat and water treatment. X-ray photoelectron spectroscopy has been used to follow the changes in the doping level and the chemical states of the nitrogen and dopant in the salts. The HClO4-protonated polyaniline undergoes deprotonation most easily upon thermal and water treatment. The SO3 - groups in the metanilic acid protonated polyaniline and the self-doped polyanilines possess different degrees of thermal stability. The SO3 - groups covalently bonded to polyaniline via sulfonation are the least stable. © 1994.