Effect of Acrylic Resin on the Protection Performance of Epoxy Coating for Magnesium Alloy

Abstract

The low toughness of epoxy resin can influence its shielding performance against a corrosive medium and strength of adhesion to metal surfaces. Extensive efforts have been made to modify epoxy resin. In this research, acrylic resin was synthesized by the solution method, and 1 wt.%, 2.5 wt.%, and 5 wt.% were added to epoxy resin (E44 brand) to prepare coatings on the surface of AZ31B magnesium alloy. The effects of acrylic resin on the mechanical and protective properties of epoxy coatings were investigated via experiments measuring impact resistance, flexibility, and adhesion as well as the electrochemical impedance technique. Compared with the pure epoxy coating, the adhesion between the coating and the substrate increases by 1.37 MPa after the addition of 2.5 wt.% acrylic resin. Meanwhile, the pencil hardness has a slight change from 5B to 6B, and the flexibility significantly improves. Therefore, the epoxy coating exhibits enhanced anticorrosive properties after the addition of 2.5 wt.% acrylic resin.