Effect of corona discharge on the stability of the adhesion of thin silicone-organic coating to polyamide fiber surface made by the sol–gel method

This paper presents the effect of pretreatment of polyamide (PA6) nonwoven with corona discharge on the stability of the adhesion of thin hydrophobic silicone-organic coating based on vinyltriethoxysilane, made by the sol–gel method. This pretreatment with corona discharge causes a change in the physicochemical properties of the PA6 fiber surface. These changes include, among others, an increase in the fiber surface roughness, wettability, and surface free energy. At the same time, XPS and EDS investigations have shown an increase in the degree of oxidation and the formation of functional polar groups on the fiber surface (C–O–, C–OH, and O=C–O–). As a result of the changes in the surface properties of pretreated PA6 fibers, a higher degree of the sol deposition was obtained compared with that for untreated nonwoven surface. The assessment of the stability of the adhesion of thin hydrophobic coating to the fiber surface was carried out on the basis of changes in the content of silica deposited on fibers and the kinetics of water contact angle after washing and abrasion processes. In the end, the PA6 nonwoven, pretreated with corona discharge, shows a higher stability of the adherence of the thin silicone-organic coating and a higher degree of hydrophobicity than the untreated nonwoven.