Preparation And Properties Of New Polysiloxane Resin Anticorrosive Coatings

Corrosion is one of the most common cases in that metal materials are destroyed in the process of use,which usually affects its strength,toughness,and mechanical properties,reduces the service life of materials,and causes great losses to people’s economy.With these problems becoming more and more prominent,it is urgent to develop a simple,stable,and efficient anti-corrosion method.Surface coating technology has been widely used because of its simple equipment,forming process,and good corrosion resistance.In this study,a new type of polysiloxane resin with rigid and flexible chain segment interaction was designed from the molecular structure,and the physical and chemical properties of the resin were adjusted by changing the length of the flexible chain segment,to improve the performance of the anti-corrosion coating.The research content mainly consists of the following two aspects:（1）Williamson’s ether formation method and silhydrogen addition reaction were used to successfully prepare a new polysiloxane resin BP0 with rigid and flexible chain segment interaction.The flexible chain segment of tetramethyl-disiloxane was added to the structure of BP0,which improved molecular compliance.Epoxy resin（EP）was used as an adhesive and BP0 resin coating with good chemical stability was prepared by drip coating.With the addition of Si elements,the surface energy of the resin coating decreases and the hydrophobic Angle reaches 113.8±1.7°.Through the analysis of the Tafel polarization curve,the corrosion current of BP0 resin coating reaches 2×10^-13 A/cm²,and the anti-corrosion efficiency is as high as 99.7%.BP0 coating in the electrochemical impedance spectra|Z|_0.01 orders of magnitude in 10¹⁰,higher than that of EP coating|Z|_0.01Hz two orders of magnitude,with strong corrosion resistance.（2）To improve the defect that BP0 resin it difficult to form a stable coating on the surface of aluminum,a new type of polysiloxane resin BP1 and BP3 were prepared by silane addition reaction with longer flexible chain segments,hamethyltrisiloxane,and decamethyldihy dropentasiloxane.BP1 and BP3 resins can directly form dense resin coatings with good adhesion on metal surfaces by drip coating.Compared with BP3,BP1 has better thermal stability,and the hydrophobic angles of the two resin coatings reach 127.4±0.9°and135.9±2.1°,respectively.Tafel polarization curves show that the corrosion currents of BP1and BP3 coatings reach 1.78×10^-13 A/cm² and 1.8×10^-13 A/cm²,respectively,and the anti-corrosion efficiency of both coatings exceeds 99.6%.BP1 and BP3 resin coating of electrochemical impedance test|Z|_0.01Hz both orders of magnitude in 10¹⁰,two kinds of resin coating are showing strong corrosion resistance.BP1 coating has better chemical stability and better long-term corrosion resistance than BP3 coating.