Enhanced Anti-Corrosion Protection of Carbon Steel with Silica-Polypyrrole-Dodecyl Sulfate Incorporated into Epoxy Coating
Nanocomposites based on silica, polypyrrole, and sodium dodecyl sulfate dopant (SiO2-PPy-DoS) were synthesized by an in situ polymerization method. The characterizations of the synthesized materials were analyzed using Fourier-transform infrared spectroscopy, energy dispersive x-ray analysis, scanning electron microscopy, thermal gravimetric analysis, and x-ray photoelectron spectroscopy. The results showed that the SiO2-PPy-DoS composite had spherical shape with size of around 250–500 nm. The electrical conductivity of the SiO2-PPy-DoS nanocomposite was measured to be around 0.287 S/cm, which was larger than that of SiO2-PPy (0.101 S/cm). An enhanced anti-corrosion protection of carbon steel substrate (CT3) using an epoxy coating containing SiO2-PPy-DoS was achieved with an impedance modulus value of 108 Ω cm−2 at 10 mHz after 840 h soaked in NaCl solution of 3%, indicating that DoS can be used as an additive to improve anti-corrosion capacity for carbon steel.