Corrosion resistance of steel treated with different silane/paint systems

Abstract

This article reports on a comparative study on the corrosion resistance of low-carbon steel substrates pretreated with different silane solutions and painted. The pure silanes used to pretreat the steel panels were 3-aminopropyltriethoxysilane (c-APS), 3-glycidoxypropyltrimethoxysilane (c-GPS), and bis(3-triethoxysilylpropyl)amine. The study also considered other silane solutions with ureido, amino, and epoxy organofunctional groups, and two bis-functional silanes: bis(c-trimethoxysilylpropyl)amine (BAS) and 1,2-bis(triethoxysilyl)ethane (BTSE). A conventional phosphate-type pretreatment was also applied for reference purposes. The pretreated panels were then finished with an alkyd/polyester aminoplast base paint. As a branch test, an acrylic/urethane paint was also applied. Different tests were conducted to evaluate the anticorrosive ability of the different silane/paint systems: outdoor exposure in an atmosphere of moderate aggressivity; accelerated corrosion test (salt fog test); and electrochemical impedance spectroscopy (EIS). The results show that the steel pretreated with certain silanes, especially c-APS, yields similar results to steel subjected to conventional phosphate pretreatment.

The influence of organophosphonic acid and conducting polymer on the adhesion and protection of epoxy coating on aluminium alloy

“…Therefore, in the panels treated with sol-gel nanocoatings as intermediate layer, we only appreciate one time constant due to a high resistance to corrosive species diffusion across the coating film, i.e., it not possible detected separately the relaxation process of sol-gel film. This result is in agreement with some works that evaluated the sol-gel films deposited as pretreatment for organic coatings depositions [15,18,40,41]. In these works the thickness of organic coating layer varied from 40 to 140 μm.…”

“…The behavior of sol-gel films based on silica precursors as adhesion promoters and its anticorrosion action has been dependent on parameters such as, concentration of silane in the starting solution [15,17,18], silica precursor nature [17,18], pH of the starting solution [16,17], immersion time in the starting solution [15], nature of organic coatings [18] and the nature of the metal substrate [19].…”

Silane-incorporated epoxy coatings on aluminum alloy (AA2024). Part 1: Improved corrosion performance

“…8). Nevertheless, amino silanes are still one of the most frequently used silanes in silane films/organic coating system [63,64] or silane-doped organic coatings [29], due to their high reactivity toward the coupling reactions with organic resins. The latter ensures better adhesion of c-APS-incorporated epoxy coating than BTSE containing superprimers (Table 1).…”

Degradation Processes in Anticorrosive Coatings for Machinery Designed for Fertiliser Application

“…However, the aging of the coating leads to its internal degeneration and loss of ability to isolate the steel substrate. It is thus necessary to choose an appropriate combination of additives and pigments to preserve the toughness of the coating -and not just in alkyd and acrylic paint systems (Johnson, 1994, Chico et al, 2008, Chico, 2012. The quality of the anticorrosion systems is then checked via tests assessing not only the elastic parameters of the new coating but also the decrease in elasticity at a given corrosive stress.…”