Electropolymerization of m‐Toluidin on Platinum Electrode from Aqueous Acidic Solution and Character of the Obtained Polymer

The electrochemical anodic electropolymerization of m-toluidin on a Pt electrode from a deoxygenated aqueous acid medium is carried out using the cyclic voltammetry technique. The effects of different parameters on the electrochemical polymerization such as the monomer, sulfuric acid, sodium sulfate concentrations, scan rate, and temperature are investigated using a conventional three-electrode cell. The results show the presence of an oxidation peak (anodic current peak) at approximately +1110 mV vs. saturated calomel electrode in all cases of the investigated parameters. A gradual increase in the anodic current peak density (Ip) is observed with a repeating number of cycles accompanied with the appearance of a new peak at low positive potential from the second repeating cycle. In addition, the effects of m-toluidin, sulfuric acid, sodium sulfate concentrations, scan rate, and temperature values have the same behavior on Ip values, in which there is an increase in Ip values till certain values (different for each parameter) and then decrease. The experimentally obtained kinetic equation is deduced from values of Ip, and a simplified mechanism for the electrochemical anodic polymerization of m-toluidin is proposed. Moreover, the diffusion coefficient, activation energy (Ea), and thermokinetic parameters such as entropy (ΔS*), enthalpy of reaction (ΔH*), and free energy change (ΔG*) are calculated. The prepared polymer is characterized by elemental analysis, UV–visible, IR, 1H NMR, X-ray diffraction, SEM, and TGA.