Preparation and performance of anti-corrosion coating for natural alkali brine colletion pipelines

To address the corrosion issue in the collection pipelines of natural alkali brine, a composite anticorrosion coating system (EP +PDMS@ SiO₂) was developed using epoxy resin (EP) and polydimethylsiloxane (PDMS) as matrix materials, with octadecyltrichlorosilane (OTS)-modified nano-silica (n-SiO₂) particles as filler materials. The corrosion resistance of the coating was evaluated through Tafel polarization analysis, electrochemical impedance spectroscopy (EIS), and weight loss method. Results showed that the addition amount of n-SiO₂ particles and modifier OTS were the key influencing factors, and the optimal addition amount was 2.1 g and 0.5 ~ 1.0 mL, respectively. When applied to N80 steel coupons, the optimized EP +PDMS@ SiO₂ coating reduced the self-corrosion current by three orders of magnitude and increased charge transfer resistance by three orders of magnitude. The corrosion rate decreased from 2.004 4% to 0.029 2%. This advancement holds the anti-corrosion coating with n-SiO₂ particles modified by OTS (EP + PDMS @ SiO₂) had a significant effect on inhibiting the corrosion of natural alkali brine collection and transportation pipelines.