Degradation of copolymers of aniline and metanilic acid

Abstract

The degradation of aniline-metanilic acid copolymer (PMA) by potentiostatic anodic polarisation was compared with the degradation of polyaniline (PAn) in order to understand the function of the pendant groups in polymer degradation. The degradation of PMA was believed to follow the same reaction pathway as the unmodified PAn, namely by attack of water molecules on oxidised polymer in the bipolaronic state. The presence of sulphonate curtailed the bipolaron production and increased the steric hindrance in degradative hydrolysis, so that the degradation of polymer was inhibited as a result. It is concluded that the pendant groups on the PAn backbone only moderated the electroactivity of the linear PAn chains in degree but not in kind.