Self-healing hybrid nanocomposite was successfully prepared from epoxy resin containing self-healing microcapsules and organosilane modified nanosilica to enhance the anticorrosion performance of an epoxy coating. Nanosilica surface was modified with (3-glycidoxypropyl)trimethoxysilane (GPTMS) and (3-aminopropyl)trimethoxysilane (APTES) to accomplish well dispersion in the polymer matrix. Perfluorooctyl triethoxysilane (POT), ethanolamine (ETA), and diethanolamine (DEA) as self-healing agents were encapsulated by polymer shell and incorporated into the epoxy coating along with modified nanosilica to form anticorrosion barrier of organic and inorganic coating on a cold-rolled steel surface (CRS). The results revealed that the self-healing hybrid nanocomposite containing 3 wt% of GPTMS-modified silica (GMS) and 10 wt%POT microcapsules possessed the best corrosion performance with the corrosion rate of 0.09 mm/year (Icorr of 0.01 mA/cm2), corrosion rating number of 9 and oxygen permeability about 0.14 barrer. The addition of modified silica (GMS) and self-healing agent microcapsules (POT) effectively increased the length of the diffusion pathways, as well as decreased the O2 permeability of the nanocomposite film.
Volume 104, March 2017, Pages 173–179