STRUCTURE-PROPERTY RELATIONSHIPS IN POLYANILINE DERIVATIVES

Different alkyl and alkoxy-substituted polyanilines were electropolymerized in acidic conditions. The steric and electronic effects of the substituents on the electrical and optical properties of the resulting polymers, were principally investigated. It has been found that alkyl-substituted anilines give less planar polymers than the alkoxy derivatives. However, alkoxy mono-substituted anilines exhibit lower conductivities than those obtained with the alkyl derivatives, because the selectivity of the head-to-tail couplings is reduced by the incorporation of a methoxy group at the ortho position. Nevertheless, more regular and processable materials have been obtained with poly(2,5-dialkoxyanilines): for instance, poly(2,5-dimethoxyaniline) exhibits a high conjugation length and a good conductivity (ca. 0.3 S/cm).