Study On Preparation And Corrosion Resistance Of The Polyethersulfone Coatings

Traditional anti-corrosion coating, which has high film thickness, high surfaceenergy, low temperate resistant levels, complicated coating process and feature ofscarifying other properties for corrosion resistance, to prevent metals, such as oilpressure sensors, chemical instruments and medical sterilization equipments, fromcorrosion is relatively tough. Because these metals are usually required to work withaccurate dimension and in harsh environments with high temperature, strong acid andalkali and organic solvent.In this paper, static contact angle test would be used to analyze and select thesurface energy from different formulas. DSC and TGA tests would be generally usedfor comparing different formula’s temperature resistance. A series of adhesion,hardness, and impact resistance tests would be used to compare mechanical propertyamong different formulas. Electrochemical impedance spectroscopy (EIS) andelectrochemical polarization curve would be used for comparing anti-corrosionperformance of different formulas and clarifying mechanism of corrosion resistance.These are powerful evidences for developing a new anti-corrosion coating, which haslow film thickness, low surface energy, high temperature resistance, good mechanicalproperty, and simple coating process.PES is selected as a matrix resin because it has strong adhesion, high temperatureresistance, high corrosion resistance, and good mechanical property. In order toreduce the surface energy and improve corrosion resistance of coating, three kinds offluororesin are chosen as modified resin: PFA, PTFE, and FEP. After comparing theimpacts of these three kinds of fluororesin on PES coatings, PTFE is chosen as thebest comprehensive property for further research. Different PTFE content of PEScoatings has different corrosion resistance. By using contact angle and EIS tests, itshows that the40-component PTFE of PES coating which has the best property. Atthe later period of the test, coating’s corrosion was controlled by electrolyte diffusion,and this result is different than the one when the pure PES coating’s corrosion wascontrolled by electrolyte activation and diffusion of corrosion products. In order toimprove the anti-corrosion property of PES/PTFE coating, three scale materials werechosen for further study: glass flake, mica flake, and basalt flake. After a series ofcomprehensive tests, it shows that mica flake of PES/PTFE coating has bettertemperature resistance and mechanical property than glass flake and basalt flake do.Because of the direct impact of scale volume on coating property, the coating propertywas compared among different amount of mica component. The result shows that the5-component mica scale coating has the best mechanical property: the contact anglereached to110degree, Tg was increased by6.6℃, coating has excellent mechanicalproperties, and the best corrosion resistance, and the corrosion was controlled byelectrolyte’s diffusion process.