Characterization of high molecular weight polyaniline synthesized at −40 °C using a 0.25:1 mole ratio of persulfate oxidant to aniline

Aniline dissolved in hydrochloric acid solution containing sufficient lithium chloride to ensure that the reaction mixture remained mobile was polymerized at temperatures of 0 and −40 °C using a 0.25:1 mole ratio of ammonium persulfate oxidant to aniline. Gel permeation chromatography (GPC), using both polystyrene and polyvinylpyridine molecular weight standards, was used to determine molecular weight values, and the structural quality of the polymer was determined by solution state 13C NMR spectroscopy. The results were compared to previous values obtained using different conditions for GPC, and structural data together with visual observations were used to propose different reaction mechanisms at the start of the reaction dependent upon the rate of oxidant addition.