Engineering of corrosion product-polymer hybrid layers for enhanced CO2 corrosion protection of carbon steel part one: Corrosion study and mechanical property investigation

The role of Poly (allylamine hydrochloride) (PAH) is investigated when applied in-situ during different stages of evolution of an iron carbonate (FeCO3) corrosion product on X65 carbon steel surfaces in a CO2 corrosion environment. We show that PAH adsorbs onto both FeCO3 and the bare carbon steel surface, producing a FeCO3-PAH hybrid structure that reduces both localised and general corrosion. The thickness and mechanical properties of naturally formed FeCO3 and FeCO3-PAH hybrid layers are characterised. The hybrid layers are shown to offer superior adhesion, as well as increased elasticity and delamination resistance compared with the naturally formed FeCO3 layer.