Corrosion, Wettability, and Adhesion of Acrylic Coatings Containing Silane-Treated Mineral Fillers on Carbon Steel

Acrylic coatings were modified by adding 0.5 and 1.0% (v/v) of epoxysilane-treated (aluminosilicate, muscovite, nepheline syenite, and wollastonite) and alkoxysilane-treated (aluminosilicate) mineral fillers. Corrosion behavior of coated carbon steel specimens was studied using polarization method. Wetting behavior and adhesion of specimens were evaluated by static contact angle and cross-cut tape test. Addition of silane-treated mineral fillers dramatically improved the corrosion resistance of acrylic coating, with composite coating filled with alkoxysilane-treated aluminosilicate at 0.5% concentration showing significantly low corrosion tendency and rate in 2 M HCl solution. Contact angle also increased with the addition of fillers, with composite coating containing alkoxysilane-treated aluminosilicate at 0.5% yielding the highest mean value. Adhesion of acrylic coatings was enhanced after addition of fillers at 0.5%, with composite coatings filled with wollastonite and alkoxysilane-treated aluminosilicate giving the lowest percent area removed after application of adhesive tape. Alkoxysilane-treated aluminosilicate was found consistent in improving the anti-corrosion characteristics, water resistance, and adhesion to carbon steel of acrylic coatings.