Extremely adherent and protective polymeric coating based on polydiphenylamine electrodeposited on steel in an organic electrolytic medium

• Published in: Journal of polymer research Vol. 29; no. 8
• Main Authors: Bouabdallaoui, Mimouna, El Guerraf, Abdelqader, Aouzal, Zaynab, Bazzaoui, Mohammed, Wang, Rongguang, Bazzaoui, El Arbi
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01-08-2022; Springer; Springer Nature B.V
• Subjects: Analysis; Characterization and Evaluation of Materials; Chemical synthesis; Chemistry; Chemistry and Materials Science; Coatings; Corrosion and anti-corrosives; Corrosion tests; Dichloromethane; Dissolution; Electric properties; Electrochemical impedance spectroscopy; Electrode polarization; Electrodes; Electrolytes; Fourier transforms; Homogeneity; Industrial Chemistry/Chemical Engineering; Infrared analysis; Infrared spectroscopy; Linear polarization; Molecular structure; Open circuit voltage; Original Paper; Photoelectrons; Polymer coatings; Polymer Sciences; Polymers; Protective coatings; Spectrum analysis; Steel; X ray photoelectron spectroscopy; X-ray spectroscopy; Electrodeposition; Polydiphenylamine coating; Corrosion; Spectroscopic and microscopic characterization
• ISSN: 1022-9760; 1572-8935
• DOI: 10.1007/s10965-022-03215-y

The present work fits into the efforts deployed to minimize the huge problems related to corrosion phenomena. As several industries are affected by the deterioration of metallic materials, new solutions need to be offered by the scientific community. In this context, we describe, in this paper, the electrochemical synthesis of polydiphenylamine coating (PDPA) on steel in an organic solution consisting of CH
2
Cl
2
as solvent and N(Bu)
4
PF
6
as supporting electrolyte. The electrolytic medium has been retained after a preliminary electrogravimetric study has shown that it can inhibit the working electrode dissolution without preventing the PDPA film formation. Spectroscopic and microscopic analyses were then achieved for the elaborated coatings. Analyses by X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR) have allowed a detailed characterization of the polymer (molecular structure, doping rate, chain length, …). In addition, morphological characterization by scanning electron microscope (SEM) confirmed that the value of the applied current density has a direct influence on the properties of the obtained polymer. The homogeneity and high adherence of the prepared PDPA film allow its use as a protective coating against steel dissolution. For this, corrosion tests were performed by studying the open-circuit potential (OCP), linear polarization curve (Tafel) as well as electrochemical impedance spectroscopy (EIS). The studies achieved in 3% NaCl solution have confirmed that the potential of the steel electrode shifts towards its passivation domain with the presence of PDPA coating. The latter is stable over time in contact with an aggressive solution and the inhibitory efficiency reached 97.2%.