Electrochemical examining behavior of epoxy coating incorporating zinc-free phosphate-based anticorrosion pigment

Protective performance of the epoxy primer containing strontium aluminum polyphosphate (SAPP) as a zinc-free phosphate-based anticorrosion pigment is aimed to assess in this work through taking advantage of electrochemical impedance spectroscopy (EIS) and electrochemical noise method (ENM). The absence of zinc offers an excellent environmentally friendly profile to the class of inhibiting compound. In the pigment extracts, the electrochemical techniques revealed superiority of SAPP compared to the conventional zinc phosphate (ZP). The behavior was connected to precipitation of a protective layer on the surface exposed to SAPP. In comparison with ZP, the most effective SAPP content in the protective primer was then determined using EIS.

► Try to find a proper alternative for zinc phosphate revealing undesirable performance.
► Coating formulation using SAPP as zinc-free phosphate based anticorrosion pigment.
► Studying corrosion inhibition of SAPP in solution phase with the use of EIS and ENM.
► EIS examining the behavior of coatings with complete formulation including SAPP.
► Determining the most effective SAPP pigment content in the protective epoxy primer.