Preparation And Corrosion Resistance Property Of Fluoroacrylate Coatings Modified By Triazine Or POSS

Energy sources,information and materials were known as the three pillars of human social development.The electronic components in the material acted as the carrier of the information dissemination,which were the bridge connecting the material and the information.Electronic components contained a great many metal elements,which were prone to chemical or electrochemical reactions with perspiration,moisture in the surrounding environment.Because of corroded metal,the efficiency of electronic components was greatly reduced,and the instrument would even produce potential safety hazards.In term of metal in electronic products,coating is the most convenient and effective method to protect electronic products from corrosion in the industry.The research of anticorrosive coatings with excellent corrosion resistance had important practical application value.The main chain of fluorinated acrylate which had good hydrophobicity and high insulation was polymerized by carbon carbon double bond in acrylate,and the perfluorocarbon chain was side chain,which possess good moisture-proof and corrosion-resistant on the substrate.In this thesis,we added melamine with triazine or polyhedral Oligomeric Silsesqioxane(POSS).Effects of adding amount and kinds of POSS on corrosion resistance of coatings were investigated.The main content consists of three parts as follows:(1)The acrylated melamine(AM)was prepared from melamine,paraformaldehyde and hydroxyethyl acrylate.The polyfluoroacrylate melamine(PFM)modified by triazine ring copolymerization was prepared by free radical polymerization.The PFM coatings with a thickness of about 2.3?m was obtained after coating heat curing.The effect of AM addition on the corrosion resistance of the coatings was investigated.The Tafel polarization curve and electrochemical alternating current impedance(EIS)test results showed that the corrosion resistance of the coating after adding AM was improved.The PFM182 coating possessed best corrosion resistance,which the self-corrosion potential was-189 m V,and the self-corrosion current density was reduced from 5.52×10^-7A·cm^-2to 1.49×10^-7A·cm^-2compared with the polyfluoroacrylate(PF)coating.The charge transfer impedance of the PFM182 coating was increased by 4 orders of magnitude compared with the PF coating,which was greatly improved.Improved the corrosion resistance of the fluorinated coating,the addition of AM might enhance the crosslinking density and compactness of the coating.(2)The octisobutyl POSS(T₈^i-Bus-POSS)was prepared from isobutyltriethoxysilane.By direct mixing,the T₈^i-Bus-POSS was added to the solution of PF,and the T₈^i-Bus-POSS/PF composite coating was obtained after coating and heat curing.The effect of T₈^i-Bus-POSS addition on the surface properties and corrosion resistance of the composite coatings was investigated.Tafel polarization curves and electrochemical ac impedance spectroscopy(EIS)showed that the addition of a small amount of T₈^i-Bus-POSS could greatly improve the electrochemical corrosion resistance of PF coatings.The composite coatings were characterized by ATR-FTIR?¹H NMR?SEM and so on.The results showed that the addition of T₈^i-Bus-POSS could produce a splendid barrier effect and reduced the corrosion rate of the metal substrate.(3)The nisobutylmethacryloyloxypropyl POSS(T₁₂^{MA/11-i Bus}-POSS)were prepared from isobutyl triethoxysilane and 3-(trimethoxysilyl)propyl methacrylate(KH-570).Through free radical polymerization,the T₁₂^{MA/11-i Bus}-POSS copolymerization modified fluoroacrylate was obtained by radical polymerization,and the PFP coating was obtained after coating heat curing.The results of ATR-FTIR and¹H NMR results showed that we had successfully prepared the T₁₂^{MA/11-i Bus}-POSS,and obtained the copolymerization products.The effect of T₁₂^{MA/11-i Bus}-POSS addition on the surface properties and corrosion resistance of the composite coatings was investigated.The test results of Tafel polarization curves and electrochemical alternating current impedance(EIS)showed that PFP coatings had excellent corrosion resistance,which the self-corrosion current density of PFP2coating was 7.36×10^-9A·cm^-2,which is 2 orders of magnitude higher than that of PF coating.The results showed that the addition of T₁₂^{MA/11-i Bus}-POSS might produced a good barrier effect,and improved the compactness of the coating,which enhanced the corrosion resistance of the fluorine-containing coating and delayed the corrosion of the metal substrate.