Exploitation of natural gum exudates as green fillers in self-healing corrosion-resistant epoxy coatings

• Published in: Journal of polymer research 2020, Vol.27 (3), Article 80
• Main Authors: Arukalam, Innocent O., Ishidi, Edith Y., Obasi, Henry C., Madu, Izuchukwu O., Ezeani, Obumneme E., Owen, Macauly M.
• Format: Article
• Language: English
• Subjects: Biopolymers; Characterization and Evaluation of Materials; Chemistry; Chemistry and Materials Science; Corrosion; Corrosion prevention; Corrosion resistance; Electrochemical impedance spectroscopy; Epoxy coatings; Exudation; Fillers; Industrial Chemistry/Chemical Engineering; Killed steels; Original Paper; Polymer coatings; Polymer matrix composites; Polymer Sciences; Protective coatings; Renewable resources; Seawater; Self healing materials; Structural steels; Substrates; X ray photoelectron spectroscopy
• ISSN: 1022-9760; 1572-8935
• DOI: 10.1007/s10965-020-02055-y

Recently, interest in developing green polymer coatings which provide self-healing and corrosion protection functions using bio-based renewable materials has significantly increased. In this study, microcapsules containing biopolymers from cashew gum and gum Arabic have been prepared by interfacial polymerization. The prepared microcapsules were individually and combinatorially embedded into epoxy coatings and the resulting composite coatings were then applied on Q235 steel substrates. The performance of the composite coatings was evaluated by immersing both scribed and unscribed coatings in simulated seawater. Surface analytical (SEM), physico-chemical (FTIR, XRD, XPS), and electrochemical impedance spectroscopy (EIS) techniques were used to investigate self-healing and corrosion resistance effectiveness of the polymer composite coatings. The obtained results revealed that cashew gum and gum Arabic could heal the scribed coating surface and subsequently suppressed corrosion reaction, without the aid of any catalyst or co-reactant. The performance was observed to be higher when the two gum exudates were combined. Thus, cashew gum and gum Arabic have demonstrated that they possess properties required for potential utilization in the formulation of marine anticorrosion and self-healing epoxy coatings.