Stability studies of polyaniline

Abstract

The stability of conductive polyaniline has been assessed at elevated temperatures, under high current density and in organic solvents. A decrease in electrical conductivity (ρ) occurs when the protonated polyaniline is subjected to temperatures above 60°C. However, at temperatures below 100°C, the decrease in ρ is reversible. The polymer can sustain a current density of 2A/cm2 over a 24 h period with no adverse effect but breaks down rapidly with a current density over 10A/cm2. Although the protonated polyaniline shows very limited solubility in organic solvents, its electrical conductivity can be significantly affected by the solvent. X-ray photoelectron spectroscopy results support the postulate that the degradation of protonated polyaniline in solvents is due to the loss of chlorine anions and/or the conversion of some of the anions to covalently bonded chlorine. Polyaniline-tetracyanoethylene complex appears to have better electrical stability than the conventional protonated polyaniline. © 1989.