The aim of this study was to evaluate the use of gamma-methacriloxypropyltrimethoxysilane (MPS) to promote the adhesion of electrogalvanized steel sheets and threaded joints when an anaerobic adhesive is selected. The influence of the pH of the silane solution on the coupling agent properties of MPS coatings was evaluated preparing two silane aqueous solutions at 1% volume of silane and two different values of pH (4 and 6). Those coatings were characterized in terms of infrared spectroscopy (FTIR), scanning electronic microscopy (SEM), contact angle and surface energy. The influence of pretreatment conditions on the adhesive performance of steels was then evaluated both by shear tests from single lap adhesive joints and screw-nut bonds. Results show that the use of coatings hydrolyzed at pH 4 exhibit better adhesion behavior than those hydrolyzed at pH 6. The shear strength of anaerobic adhesive joints dramatically increases, showing a cohesive failure. This is related to the hydrolysis and condensation rates of silane solution and the stability of the metallic surface in contact with silane solution at the studied pH values.
surface treatment by chemical solutions; silane treatment; sealants; adhesion by chemical bonding; threaded joints; gamma-methacryloxypropyltrimethoxysilane; aluminum-alloy; corrosion-resistance; hydrolysis process; galvanized steel; films; surface; strength; aminopropyltriethoxysilane; durability