Preparation and Properties of Inorganic and Organ Silane Composite Hybrid Membrane on Surface of Aluminum Plates

Abstract

To replace traditional phosphating and hexavalent chromium passivation technologies， which cause serious environmental pollution，a silane passivation solution was prepared.This solution was composed of amino silicone resin， polyurethane resin and inorganic metal.It was then coated on the degreased aluminum plate surface to form an organic-inorganic hybrid film.The study investigated the effects of various factors on the corrosion resistance of the hybrid membrane: the pH value of the passivation solution， the mass fractions of amino silicone resin and polyurethane resin and the types of inorganic metal ions (Zn2＋， Mn2＋， Ni3＋and Ce3＋).The morphology and structure of the hybrid membrane were characterized by infrared spectrum (IR)， scanning electron microscopy (SEM) and thermogravimetric analysis (TGA).Characterizing the corrosion resistance of hybrid membrane by measuring the open circuit potential， EIS spectrum and Tafel polarization curve of aluminum plates coated with hybrid membrane under different conditions through electrochemical experiments.Results showed that the hybrid membrane exhibited good corrosion resistance when the pH value was around 4.5， the mass fraction of amino silicone resin was 15.0%， the mass fraction of polyurethane resin was 10.0%， and the metal ion was 1.5%Zn2＋.

Keywords

• silane passivation solution|hybrid membrane|amino silicone resin|polyurethane resin|corrosion resistance