Restore State And Doped Polyaniline Preparation And Corrosion Resistance Can Study

Among many conducting polymers, as Polyaniline has lots of excellent characteristics superior to those of others, it was chosen to be the objective of the corrosion research.At first, Polyaniline was synthesized by the improved chemical oxidation technique, then, PANI/HCl, PANI/TSA and PANI/DBSA were obtained by doping emeraldine (EB) with HCl, 4-methyl benzene sulfonic acid(TSA) and dodecylbenzene sulfonate acid (DBSA), separately. Leucoemeraldine was obtained in the N-dimethylformamide by using phenylhydrazine deoxidizing emeraldine in N₂ atmosphere. The resulting polymers were characterized by SEM, element analysis, UV-visible and FT-IR, investigated the conductivity and the solubility in the organic solvent in the room temperature. The result indicated that deoxidizing emeraldine destroyed of quinone diamide conjugate structure, both of the conductivity and solubility were reduced. The charge was delocalized along the molecular chains after protonic acid doped, which was beneficial to the electric conductivity. The solubility of samples increased by the organic protonic acid doped Polyaniline because the counter-ions hanged on the aniline side chain which could reduce the force between chains. Doped Polyaniline by DBSA which had bigger anion had the best conductivity and solubility.The anticorrosion coatings of Leucoemeraldine/epoxy resin were prepared according to certain formula and spreaded on stainless steel surface by circumgyrating. The appearace and thickness of the films were observed by SEM, and the anticorrosion property in the presence of 3.5% NaCl aqueous solution was investigated by the relationship of open circuit potential and time, Tafel polarization curves and EIS. The result indicated that, the corrosion potential of the Leucoemeraldine coating on stainless steel raised 142 mV, and the corrosion current was reduced 10 times. Leucoemeraldine could form passivation film on the surface of stainless steel, affording persistent protection. Leucoemeraldine had the better anticorrosion property than emeraldine. The anticorrosion coatings of doped PANI/ hydroxyl acrylic resin were prepared and spreaded on magnesium surface by circumgyrating. The appearace and thickness of films were observed by SEM, and the anticorrosion property in the presence of 3.5% NaCl aqueous solution was investigated by the relationship of open circuit potential and time, Tafel polarization curves and EIS. The result indicated that the films had large impedance and could make corrosion potential was higher and the corrosion current was lower. PANI/DBSA coating had the best anticorrosion property compared with emeraldine and PANI/TSA.