Preparation And Properties Of Epoxy/Basalt Flakes Anticorrosion Coatings

Metal corrosion has brought serious loss to human society.Among various anticorrosion treatment methods,the organic coating which can isolate the corrosion factors from the metal base is the most economical and convenient one.Adding flakes of metals or glasses into coatings can extend the transmission path of corrosion factors and improve the protective performance of coatings effectively.Epoxy is the most commonly used organic coating,and it has advantages over others due to its excellent adhesion,low curing shrinkage,good mechanical properties,and chemical inertness.However,the volatilization of solvents will cause environmental pollution and pose potential safety hazards.Glass flakes have poor acid/alkali-resistance due to high alkaline oxide content.In this paper a new high performance environment-friendly anticorrosive coating is prepared using solvent-free epoxy resin as film-forming agent and basalt flakes as main antirust fillers,respectively.The best coating is formed when adding 15g of thinner（622）,1g defoamer（BYK-A530）and 50g curing agent（T-31）in 100g epoxy（E-51）.A dispersant（BYK-163）,with 20 wt%of the basalt flakes,is required to disperse the flakes in epoxy.Basalt flakes,with glass flakes as a reference material,were soaked in H₂SO₄（1 mol/L）and NaOH（1 mol/L）,and the results obviously indicated a better acid/alkali-resistance of the basalt flakes.The EIS test,water absorption test and salt spray experimental results demonstrated that the optimum content of basalt flakes in the anticorrosion coating is 10 wt%.In the long term,the undesirable interface between inorganic basalt flake and organic epoxy may deteriorate the anticorrosive properties of the coatings.Therefore,in order to improve the interface and thus the coating performance,the surfaces of basalt flakes were modified by KH-560.Infrared spectroscopy and SEM were used to evaluate the modification effect.Through EIS test and water absorption test,it was found that the surface modification effectively improved the coating performance.