The effect of silanes on paint adhesion and sites of failure

✍ Scribed by P. Walker

• Publisher: John Wiley and Sons
• Year: 1991
• Tongue: English
• Weight: 502 KB
• Volume: 17
• Category: Article
• ISSN: 0142-2421
• DOI: 10.1002/sia.740170709

✦ Synopsis

Abstract

It is shown that the exposure of organic coatings to high humidity or water immersion causes a rapid loss of adhesion. The use of organofunctional silanes of the general formula R^1^—Si(OR)~3~, where R^1^ is an amino, epoxide, mercapto, methacryloxy or vinyl group, can materially improve the initial, wet and recovered adhesion of epoxide, urethane and alkyd coatings to mild steel and aluminium substrates when used as pretreatment primers and additives.

XPS work on the locus of failure of surface coatings on aluminium substrates indicated that although some local loss of adhesion to the substrate may occur, the predominant mode of failure is cohesive within the paint film. These findings are discussed in the light of current theories.