STRUCTURE-PROPERTY RELATIONSHIPS IN POLYANILINE DERIVATIVES

Different alkyl and alkoxy-substituted polyanilines were electropolyme rized in acidic conditions. The steric and electronic effects of the s ubstituents 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 derivat ives. However, alkoxy mono-substituted anilines exhibit lower conducti vities than those obtained with the alkyl derivatives, because the sel ectivity 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-dialkoxyani lines): for instance, poly(2,5-dimethoxyaniline) exhibits a high conju gation length and a good conductivity (ca. 0.3 S/cm).