ABSTRACT
The surfaces of SiO2 ultra-fine particles with different sizes have been modified by γ-(2, 3-epoxypropoxy)propytrimethoxysilane (KH-560) silane coupling agent. Then the homogeneous fluoropolymer/SiO2 composite coatings have been successfully prepared on mild steel substrates. The surface grafting of KH-560 on SiO2 particles was detected by means of Fourier transform infrared spectroscopy, thermo gravimetric analysis and transmission electron microscopy. The surface morphologies and corrosion resistance of fluoropolymer/SiO2 composite coatings were characterised by field emission scanning electron microscopy, potentiodynamic polarisation as well as electrochemical impedance. The results showed that KH-560-modified SiO2 particles can decrease agglomeration effectively, and the particles play a beneficial role in improving the corrosion resistance of the coated steel significantly. There exists an obvious effect of SiO2 particles size on the corrosion resistance of fluoropolymer/SiO2 composite coatings. Also, the SiO2 particles with diameter of 150 nm are of the best effect among all particle sizes.
Disclosure statement
No potential conflict of interest was reported by the authors.