Oxidative copolymerization of aniline with o- and p-toluidine by ammonium per sulfate: Kinetic and pathway

The kinetic study on the oxidation of aniline with oand p-methylaniline by ammonium persulfate (APS) has been carried out. The course of copolymerization was investigated by UV-vis spectroscopic method. Structural characterization was studied by FT-IR spectral analysis. The electronic spectra of the copolymers poly(aniline-co-p-toluidine) and poly(aniline-co-o-toluidine) show hypsochromic shift. The shift has been observed in the bands corresponding to π→π* transition as well as in the exciton transition. The increase in absorbance recorded during the reaction for different concentration of aniline, oand ptoluidine at various times of intervals of polymerization reaction indicates a growth in the polymer formation. The degradation curve can be fitted reasonably well by an exponential decay of APS, suggesting first order kinetics. The resulting first-order rate constant was used to calculate the rate of copolymer formation using the rate equation –d[A]/dt =kcn.