Preparation and properties of silane coupling agent modified steel slag as functional filler for anti-corrosion coating

The chemical composition and high wear resistance of steel slag (SS) make it a potential alternative to traditional inorganic fillers. 3-Aminopropyltriethoxysilane (KH550) modified steel slag (MSS) was successfully prepared, and its application in epoxy (EP) anti-corrosion coating was introduced. Due to the grafting of silane coupling agent functional groups onto the surface of SS, MSS exhibited improved solubility in xylene organic solvent and reduced agglomeration. When the MSS content was 15 wt.%, the contact angle of the MSS/EP composite coating was 101 degrees, and the abrasion was only 0.07 g, compared with 56.2 degrees and 0.13 g, respectively, for the pure EP coating. The corrosion resistance of coatings was investigated by performing the electrochemical test (impedance) after immersion in a 3.5 wt.% NaCl solution. The electrochemical test results showed that the impedance modulus of the 15 wt.% MSS/EP composite coating at low frequency (Z(f) = 0.01 Hz) was approximately 1.08 x 10(7) omega cm(2), which was two orders of magnitude higher than that of the pure EP coating.