Corrosion Protection Performance and Spectroscopic Investigations of Soluble Conducting Polyaniline-Dodecylbenzenesulfonate Synthesized via Inverse Emulsion Procedure

Abstract

Corrosion protection performance of a completely soluble polyaniline-dodecylbenzenesulfonic acid salt (PANI-DBSA) on C45 steel has been studied with electrochemical impedance and potentiodynamic measurements. Chloroform is the most suitable solvent to process the pristine PANI-DBSA because of negligible interaction of the solvent with the polyaniline (PANI) backbone. An anodic shift in the corrosion potential (E = ~70 mV), a decrease in the corrosion current and a significant increase in the charge transfer resistance indicate a significant anti-corrosion performance of the soluble PANI deposited on the protected steel surface.Corrosion protection follows the mechanism of formation of a passive oxide layer on the surface of C45 steel. In situ UV-Vis spectroscopy was used to investigate the differences in permeability of aqueous anions into PANI-DBSA. Preliminary results of electron diffraction studies show that PANI-DBSA possesses an orthorhombic type of crystal structure. An increase in the feed ratio of DBSA to aniline increases the tendency of aggregation of spherical particles of PANI obvious in transmission electron microscopy. PANI-DBSA slowly loses its electrochemical activity in acid free electrolyte without undergoing degradation.2

Benzoyl‐Peroxide‐Initiated Inverse Emulsion Copolymerization of Aniline and o‐Toluidine: Effect of Dodecylbenzenesulfonic Acid on the Physicochemical Properties of the Copolymers

“…[25] In a 2:1 mixture of toluene and 2-propanol, with a gradual increase of the amount of PANI dissolved, this band is blue shifted by more than 50 nm, such a blue shift was not observed for POT. The shift with PANI (at lower concentration) is attributed to the rearrangement of the compact coil conformation to an extended coil conformation.…”

“…[23] As in the case of PANI, copolymers dissolved in chloroform possess higher absorbance ratios (A % 800 / A % 350 ) indicating that when dissolved in chloroform, copolymers retain the protonation. [25] In a 2:1 mixture of toluene and 2-propanol, absorbance ratios depend on the amount of polymer dissolved, indicating interaction between the -NH group of polymer and -OH group of the solvent. However, the absorbance ratios of POT depend neither on the nature of the solvent nor on the amount of the polymer dissolved, which, as mentioned earlier, confirms the absence of conformational rearrangements in this polymer.…”

Investigations of chemically synthesized poly(aniline‐co‐o‐toluidine)s doped with dodecylbenzenesulfonic acid

“…DBSA, being a large molecule, facilitates the solubility of the resulting PANI. Electrochemical and spectroelectrochemical investigations of soluble PANI–DBSA have already been reported 8, 9…”

Electrochemical synthesis of polyaniline from aniline/cyclodextrin solutions

“…For such purpose different counter-ions were used during synthesis [1][2][3], polymer backbone was functionalised [4][5][6], different working electrode templates were used [7,8] or conductive polymer was mixed with carbon nanotubes [9]. In addition, there were attempts to modify conductive polymers by cyclodextrin incorporation onto polymer chains or within conductive polymer layer [10][11][12][13][14][15][16][17][18][19][20][21][22][23][24] in order to achieve molecular assemblies with subsequent applications in a supramolecular chemistry.…”