Microencapsulation of quinoline as a corrosion inhibitor in polyurea microcapsules for application in anticorrosive PU coatings

The use of reservoirs containing corrosion inhibitors as active substances for corrosion protection is an issue of great interest in the scientific literature. The aim of the present study is to encapsulate quinoline, a corrosion inhibitor, into a micro-reservoir to overcome disadvantages caused by its direct addition into a coating layer. Quinoline incorporated microcapsules with different core solvents were synthesized at room temperature by an interfacial polymerization method. The morphologies, wall structures, particle size and thermal properties of the synthesized microcapsules were investigated. The release study of core material was carried out by loss on drying and UV spectrophotometric methods. The prepared quinoline based microcapsules were incorporated in polyurethane (PU) coatings to study their effect on corrosion of substrate. The anticorrosive performance of coatings loaded with different weight % of microcapsules containing quinoline was tested by immersion of the PU coated mild steel specimens in 5 wt% HCl solution by visual observation and weight loss measurements.