Tribological and Anticorrosion Behavior of Coating Systems Based on Polyurethane and Organic Silicon Compounds

Coating systems based on polyurethane (PU) coatings and coatings of oligomethylsiloxane resin (OMES) or oligomers of hydrolyzed heptadecafluorotetrahydrodecyltrimethoxysilane (HFS) were applied on carbon steel by the spin coating method. Wettability and tribologicalproperties of coating systems were determined by contact angle measurement and tribotechnical test. Corrosion resistance of coated carbon steels was investigated by electrochemical impedance spectroscopy. It was noted that the modification of the PU layer with silicon organic compounds increased its hydrophobicity and wear resistance. The water contact angles were 63.1 degrees for PU coating alone, 81.2 degrees for PU/OMES system and 115.8 degrees for PU/HFS system. The modification of polyurethane coating with OMES reduced its friction coefficient from 0.14 to 0.04. Corrosion resistance of PU coatings was not improved with presence of OMES layer but significantly enhanced with presence of HFS layer.