Corrosion inhibition performance of polyolefin smart self-healing composite coatings modified with ZnO@β-Cyclodextrin hybrid particles

Abstract

Corrosion is a global problem that results in substantial economic loss and is life-threatening as well. Currently, the utilization of self-healing coatings involving smart carriers encapsulated with the appropriate self-healing agents is a topic of great interest. Following this strategy, our work reports the synergistic corrosion inhibition performance of polyolefin-based smart coatings containing modified hybrid-based particles. The hybrid particles (ZnO@β-CD) comprising zinc oxide (ZnO) and β-Cyclodextrin (β-CD) were synthesized and modified with 2-mercaptobenzothiazole (2-MBT). The synthesized unmodified and modified hybrid particles were characterized by numerous techniques. TGA analysis confirmed that 2MBT was effectively loaded into ZnO@β-CD with almost 43% loading. UV-vis spectroscopic analysis results suggested that the self-release behavior of 2MBT is more pronounced in the acidic environment compared to the basic and neutral environment due to the dissociation of ZnO in the acidic environment. In the next stage, the synthesized unmodified (ZnO@β-CD) and modified (ZnO@β-CD-2MBT) hybrid particles were reinforced into a polyolefin matrix, followed by its application on steel substrate via dip-coating technique to formulate smart composite coatings. The Electrochemical impedance spectroscopy (EIS) results conducted on the developed smart composite coatings demonstrated that polyolefin coatings reinforced with modified hybrid particles (ZnO@β-CD-2MBT) displayed improved corrosion inhibition performance (98 GΩ cm2) as compared to the composite coatings (87 GΩ cm2) containing unmodified particles ((ZnO@β-CD) in 0.56 M NaCl solution after 20 days of immersion. This decent improvement in corrosion resistance behavior is attributed to the synergistic corrosion inhibition effect experienced due to the combined corrosion inhibition effect of ZnO and 2MBT.