Preparation And Properties Of The Corrosion Resistance Of The Polyphenylsulphone Coatings

Recently, as the development of industry, more and more attention is paid to the anti-corrosion of steel. Traditional anti-corrosive coatings are mainly composed of normal polymers which have several common weak points, such as thick film, short service time and low thermos stability. It is impossible to meet the needs of modern society for the performance of anti-corrosion coatings only by developing the formulation and modifying the normal polymers.Polyphenylsulphone(PPSU) is a kind of high performance special engineering plastic, especially its excellent toughness make it a proper polymer used for coatings. Polyetheretherketone(PEEK) is an excellent special engineering plastic with high compactness and stiffness; therefore the penetration resistance and anti-corrosion performance of PEEK are outstanding. However the PEEK has a poor processing property because it is almost can’t be dissolved by any solvents; on the other hand, the cost of PEEK is too high. Considering all these, it is clear that it is a hard work to make the PEEK widely used in coating industry.In this paper, the PEEK powder is used as coating filler and the PPSU is used as the main binders of the coating. The mix solvent system is composed of N-methylpyrrolidone(NMP), N,N-dimethylacetamide(DMAC), methylbenzene and butanone. In order to pursue excellent anti-corrosive performance of PEEK, the coating was cured at high temperature. The anti-corrosive performance was evaluated by conducting the immersion test, EIS(Electrochemical Impedance Spectroscopy) test and salt spray test. The morphology of the coating was studied by SEM to study the state of PEEK.In order to improve the performance further, Polytetrafluoroethylene(PTFE) is used to improve the hydrophobicity of coating to expand its application; the hydrophobicity was evaluated by testing the surface contact angel. The anti-corrosive performance was evaluated by conducting the immersion test, EIS(Electrochemical Impedance Spectroscopy) test and salt spray test. The morphology of the coating was studied by SEM to study the state of PTFE.The result showed that the compatibility between the PPSU and PEEK was very well. The PEEK:PPSU=12:8 was the best formula. The compatibility of the PTFE with PPSU and PEEK was not so well, the PPSU:PEEK:PTFE=7:3:4 was the best formula.