Biobased self-healing polyurethane coating with Zn micro-flakes for corrosion protection of AA7475

Author(s)

Nardeli, Jessica V. ^{[1, 2]} ; Fugivara, Cecilio S. ^[1] ; Taryba, Maryna ^[2] ; Montemor, M. F. ^[2] ; Benedetti, Assis V. ^[1]

Affiliation

^[1] Univ Estadual Paulista UNESP, Inst Quim, BR-14800060 Araraquara, SP - Brazil

^[2] Univ Lisbon, Ctr Quim Estrutural, DEQ, Inst Super Tecn, Av Rovisco Pais, P-1049001 Lisbon - Portugal

• Document type: Journal article
• Source: CHEMICAL ENGINEERING JOURNAL; v. 404, JAN 15 2021.
• Web of Science Citations: 5

Abstract

AA7475 is a modern and competitive high strength alloy of relevance to the aerospace industry. In this work biobased organic polyurethane coatings were prepared from vegetable oils (crambe oil and castor oil) without (blank coating) and with incorporation of Zn micro-flakes to impart corrosion inhibition. Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy (FTIR-ATR) confirmed the incorporation of zinc in the polymeric matrix and atomic force microscopy (AFM) confirmed the coating homogeneity. The barrier properties of the coatings were studied by electrochemical impedance spectroscopy (EIS) and indicated better corrosion resistance for the sample with the highest content of Zn micro-flakes. Localized electrochemical techniques, namely the scanning vibrating electrode technique (SVET), pH micro-potentiometry (or scanning ionselective electrode technique - SIET) and localized electrochemical impedance spectroscopy (LEIS) permitted to discriminate the details of the corrosion inhibition process. The results demonstrated that the Zn-containing coatings provide effective corrosion protection of the AA7475 and the protective ability improved significantly in the presence of 7.5 wt% Zn micro-flakes in the coating. (AU)

• FAPESP's process: 18/09040-9 - Evaluation of the self-healing properties of polyurethane coatings derived from vegetable oils with and without addition of corrosion inhibitors using localized electrochemical techniques and the study of chemical and structural properties.
• Grantee: Jéssica Verger Nardeli
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate
• FAPESP's process: 15/10554-9 - Polyurethanes Coatings derived from vegetable oil with and without addition of corrosion inhibitors: chemical, structural and corrosion resistance.
• Grantee: Jéssica Verger Nardeli
• Support Opportunities: Scholarships in Brazil - Doctorate