| Iron oxide as a widely used pigment can improve the performance of epoxy coating.However,the poor compatibility of inorganic iron oxide with organic resin and the bad dispersity of iron oxide in resin increase the defect of the coating,influencing the corrosion-resistance performance of the coating.In this work,the epoxy resin is chosen as the modification agent to modify iron oxide using the mothod of mechanical and thermal energy combination.Iron oxide modification powder is added into epoxy resin to manufacture coating.Corrosion-resistance property of the coating is studied and the influence of modified iron oxide on coating protective performance is discussed.The feasibility of epoxy resin modifies iron oxide is explored.The influence rule of ball milling condition to modification effect is explored by the study of grinding temperature,grinding time and rotate speed,and then,the optimal modification craft is obtained.Iron oxide powder by high-temperature ball milling is characterized.The crystal structure of iron oxide powder does not change after high-temperature ball milling.However,the hydrophilic of iron oxide decreases,the lipophilicity increases,and the dispersion stability of iron oxide particle in epoxy solution is improved.Iron oxide surface is modified by epoxy resin film coated around iron oxide particle.Iron oxide modification powder is added into epoxy resin to manufacture coating,and the coating is characterized.Compared with unmodified iron oxide coating,the dispersibility of modified iron oxide in epoxy resin is improved,the aggregate phenomenon is lessened,and the interfacial compatibility is improved,enhancing the interfacial bonding.EIS results indicate that the impedance modulus at low frequency for modified iron oxide coating still maintains above 1010?.cm2 which is four orders of magnitude higher than unmodified iron oxide coating after 3896 h immersion.The results of adhesion strength indicate that modified iron oxide coating has higher adhesive force with metallic matrix after 3000 h immersion.Tensile test results show that the tensile strength of modified iron oxide coating is improved.All the results manifest that modified iron oxide improves the corrosion-resistance performance of the coating.The restrain effects on water diffusion are different for the unmodified and modified iron oxide coatings with the addition of 5%,10%,20%and 30%.For the same addition,the modified iron oxide coatings have stronger restrain effects on water diffusion than those unmodified iron oxide coatings,and the coating with 10%addition of modified iron oxide is the best in restraining water diffusion.The results of EIS and adhesion strength manifest that the modified iron oxide coatings have better protective property for the same addition,and the coating with 10%addition has better protective property for the modified iron oxide coatings.The tensile strength of modified iron oxide coatings are higher than those unmodified iron oxide coatings,and the tensile strength of modified iron oxide coatings increase with the increasing of iron oxide content.All the results manifest that modified iron oxide coating with 10%addition has better corrosion-resistance performance.Graft quantity of epoxy resin on the surface of iron oxide is calculated using TG data of iron oxide powder under different ball milling temperatures.Graft quantity on iron oxide surface increases with the rise of the grinding temperature,the maximum graft quantity achieves at 120?,and then,the graft quantity decreases with grinding temperature increasing.The dispersibility of iron oxide in epoxy resin and the compatibility of iron oxide with epoxy resin are improved with the increase of graft quantity on the surface of iron oxides,resulting in the corrosion-resistance performances of the coatings are improved. |
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