Polymeric Organo‐Silane Coatings for Aluminum Alloy Corrosion Protection by Self‐Assembled Metho

The protective performances of coating formed by organo‐silane with a linear alkyl chain for promoting aluminum alloy corrosion protection were evaluated by electrochemical techniques. The coatings were self‐assembled in the hydrolyzed hydroalcoholic bath of n ‐octyltriethoxysilane (OS) and cured at hot air oven by different time. The coatings prepared by the less self‐assembled number and shorter cured time, were always porous and scarcely protective. On the contrary, those built by the more self‐assembled number and the longer cured time had higher coverage on aluminum surface and favorable corrosion resistant property. The best results were obtained when n ‐octyltri‐ethoxysilane (OS) was hydrolyzed 25 h, self‐assembling of OS was conducted for five times and the multi‐layers were cured at 120 for 1∼2 hours. In this case, the thicker, high cross‐linked and more scarcely defective layer was formed on aluminum alloy surface.