Synthesis, Characterization, and Investigation of Inhibitor Release of the Anticorrosion Sol–Gel Hybrid Nanocomposite Coatings

Abstract

Corrosion protective coatings were developed on 1050 aluminum alloy through the sol–gel process using 3-glycidoxypropyltrimethoxysilane (GPTMS) and tetramethoxysilane (TMOS), and diethylenetriamine (DETA) as the cross-linking agent. Two organic corrosion inhibitors (2-mercaptobenzothiazole and 2-mercaptobenzimidazole) were applied to induce inhibition properties. Salt spray method was employed to evaluate the corrosion protection performance. It was found that organic inhibitors improved the corrosion resistance of the coatings. Formation of silica networks from two precursors of GPTMS and TMOS in the presence of DETA curing agent was confirmed by FTIR. Distribution of silicon and sulfur, surface morphology and the presence of nanoparticles in the matrix were studied by SEM, EDX and TEM techniques. Physical and thermal properties of the coatings were investigated by water contact angle, Pull Off and DMTA tests, respectively. The results revealed that the presence of the organic inhibitors decreased the hydrophilicity and increased adhesion strength but has no significant effect on thermal properties. The controlled release of MBI was also investigated by UV-Vis spectrophotometry.