Polypyrrole and polyaniline prepared with cerium(IV) sulfate oxidant

The conducting polymers, polypyrrole and polyaniline, were synthesized by chemical oxidative polymerization of the corresponding monomers in 0.1 M sulfuric acid using cerium(IV) sulfate as the oxidant at mole ratios of oxidant-to-monomer ranging from 0.5 to 3. The yields of the oxidation products were determined, and the samples were characterized with respect to their elemental composition, molecular structure, and morphology. The conductivity of polypyrrole prepared in 0.1 M sulfuric acid, 10−1 to 100 S cm−1, was higher compared with the conductivity of polyaniline prepared under the same conditions, 10−3 to 10−1 S cm−1. The loss of mass after deprotonation with ammonium hydroxide is reported, and discussed in terms of the type of protonation as also reflected by FTIR spectroscopy. The conductivity of polypyrrole bases remained at relatively high level, 10−5 to 10−3 S cm−1, while PANI bases became non-conducting, 10−12 to 10−10 S cm−1. The polymers had a granular morphology in all cases.