Performance of bis-[triethoxysilylpropyl] tetrasulfide silane coatings for improved corrosion resistance of carbon steel
Abstract
This work was aimed at evaluation of the effect of sol–gel coating of bis-[triethoxysilylpropyl] tetrasulfide (BTESPT) on improved corrosion resistance of carbon steel samples in a 0.5 M NaCl solution. The samples of carbon steel and phosphated carbon steel without/with cerium conversion films coated with BTESPT or BTESPT doped with cerium, as a corrosion inhibitor, were investigated. The composition and structure of the samples were characterised by the scanning electron microscope (SEM) and the X-ray photoelectron spectroscopy (XPS) techniques, while their corrosion behaviour was investigated applying voltametric and electrochemical impedance spectroscopy (EIS) measurements. The data obtained have shown that all phosphated carbon steel samples (without/with cerium conversion films) with the sol–gel coatings exhibited better protective abilities with respect to those of carbon steel. The results of EIS measurements revealed that the cerium conversion coatings or the addition of cerium nitrate, as an inhibiting agent, to BTESPT can certainly help in corrosion protection of carbon steel substrates. The film of BTESPT doped with Ce is more protective than that of non-modified ones.