Polyaniline alloys with poly(3-sulfonato-4-hydroxystyrene)

Oxidation of aniline with ammonium peroxodisuffate in aqueous solutions containing poly(3-sutfonato-4-hydroxystyrene) gave polymer alloys (or polymer blends) with a general composition of {(—C6H4NH—)[—CH2—CH(C6H3·OH·SO3–)—]x(H2SO4)y·zH2O}n. Their electrical conductivities depended on the composition and varied between 10–5 and 0.5 S cm–1 at 300 K. The polyaniline salts were soluble in water and exhibited an electronic absorption band characteristic of emeraldine salts at 800 nm. The corresponding alkaline solutions showed a band due to emeraldine bases at 600 nm. These bands showed a pH dependence that is a consequence of an interchain interaction between two kinds of polymer chains. A polymer with x= 04, y= 1.2 and z= 3.6 was soluble enough to observe EPR spectra, whose pH dependence showed that, with increasing pH, deprotonation occurs at polarons prior to deprotonation at bipolarons.