High yield preparation of a soluble polyaniline derivative

The effect of pH, temperature, monomer/oxidant molar ratio, catalysts and ionic strength on the reaction yield and electrical conductivity of chemically synthesized poly (o-methoxyaniline) was studied. Based on this, poly (o-methoxyaniline) was prepared in the presence of p-toluene-sulfonic, dodecyl-benzene-sulfonic and dodecyl-sulfuric acids. Poly(o-methoxyaniline) was obtained with 90% yield and a conductivity of 0.1 S cm−1 when p-toluene-sulfonic acid was used. The use of functionalized acids increased the thermal stability of the polymer in relation to HCl with no changes in the electric conductivity. The polymer is soluble in common organic solvents, enabling the preparation of films by casting. We also discuss the polymerization kinetics of o-methoxyaniline in the presence of HCl and of the functionahzed acids as a function of monomer/oxidant ratio.