Effects of nanoparticles on the corrosion resistance of fluoropolymer coatings on mild steel

The surfaces of nanoparticles of SiO 2 , TiO 2 and Al 2 O 3 have been modified by γ-(2,3-epoxypropoxy)propyltrimethoxysilane (KH-560) in order to achieve proper dispersion of nanoparticles and possible chemical interactions between nanoparticles and polymeric coatings, and then the homogeneous fluoropolymer coatings containing nanoparticles of SiO 2 , TiO 2 and Al 2 O 3 have been successfully prepared on mild steel substrates. The surface morphologies of the coatings were characterised by field emission scanning electron microscopy. The effects of incorporating various nanoparticles on the corrosion resistance of fluoropolymer-coated steel were investigated by potentiodynamic polarisation curve, electrochemical impedance spectroscopy and salt spray tests. The results showed that KH560-modified nanoparticles can decrease agglomeration effectively, and the nanoparticles play a beneficial role in improving the corrosion resistance of the coated steel significantly. In addition, SiO 2 nanoparticles are of the best effect among three kinds of nanoparticles.