Study On Structures And Properties Of Air Curing Feve Paints And Preparation Of High-Performance Feve Paints

In this dissertation, the properties of various FEVE paints were studied, and so the basic data of FEVE paints were accumulated; High-performance FEVE paints, and FEVE / CNTs paints were prepared, and the dirt resistance of FEVE paints were investigated; the design of FEVE coating systems and the strict control of construction quality were also studied.1. The weathering resistance, thermal stability, mechanical property and anti-corrosive performance were investigated by various test methods and means. 1) The excellent weathering resistance of FEVE paints, the type and district differences of weathering resistance, of different types of FEVE paints, were investigated by weather exposure test, weatherometer test, and ESEM analysis. The results show that The FEVE resins polymerizated by these ether or big vinyl monomers have more excellent weathering resistance; The FEVE paints are sensitive to humid tropical condition and salt fog, but are not sensitive to only ultraviolet light. 2) The thermal stability of FEVE fluorocarbon coatings was investigated, by air oven ageing, thermo-gravimetric analysis(TG), and tensile property after hot air ageing, the results show that The FEVE resins with TFE have better heat resistance than CTFE, and with vinyl ether than with vinyl esters. 3) The tensile stress-strain curve of various FEVE paints, and the compatibility of FEVE paint and epoxy primer were investigated, the results show that FEVE paints have good mechanical properties, and good matching with epoxy primer. 4) The different types of FEVE paints resistance to acid and alkali and resistance to organic solvent were compared and analyzed, the results show that all types of FEVE paints have good resistance to acid, the vinyl ether and big vinyl esther FEVE paints has good resistance to alkali, but the vinyl acetate FEVE paints has poorer resistance to alkali; All FEVE paints have very low degree of swelling in nonpolar solvent(trifluorochloroethylene vinyl acetate copolymer hardly resolves in nonpolar solvent), have high degree of swelling in weak polar solvent, and have lower degree of swelling in strong polar solvent. 5 ) Electrochemical Impedance Spectroscopy (EIS) was applied as a principal tool to appraise the corrosion resistance of FEVE paints, the results show that FEVE coating films (23μm) keep as an isolated layer with large resistance value and small capacitance value in 3.5% NaCl water solution in longer time (40d), indicating that FEVE coating films have good permeation resistance and anti-corrosion. 2. FEVE paints with excellent weathering resistance, good anti-corrosion, and good appearance of film, were prepared, with tetrafluoroethylene vinyl ether copolymer as film forming resin, by the choice of curing agents, solutions, and additives. The films of FEVE anti-corrosive coating systems have very slight discoloration and very slight blinding after 5000h weatherometer test (GB/T1865); The films have no abnormal after 5000h salt fog resistance test; The films have no discoloration and no blinding after four years weather exposure test in Beijing distract; The films have no discoloration and only slight blinding after two years weather exposure test in Hainan distract.3. The effects to improve the Dirt Resistance of Air Curing FEVE Paints with siloxane fluoride hydrophilic additive, modified organic silicon antigraffiti additive, or TiO₂ photocatalyst were analyzed, the results show that it is the most effective means with the proper hydrophilic additive to improve the self-cleanliness and dirt resistance of paint film. Surface elements and water contact angle of coating films were characterized by using XPS and measuring apparatus for contact angle. The results show that the hydrophilic additive evidently accumulates on the surface of paint films, and hydrolyzes rapidly to produce hydrophilic groups, so steady hydrophlicity of the surface is accomplished, and water contact angle keeps below 35°.4. Carbon nanotubes/FEVE fluorocarbon composite coatings were prepared. The dispersibility of carbon nanotubes in FEVE matrix, mechanical property, thermal stability and conductivity of composite coatings were investigated. The results show that carbon nanotubes were well dispersed in the fluorocarbon resin solution by adding the wetting and dispersing additive Disperbyk?-2050. Adding carbon nanotubes improves the tensile strength of the fluorocarbon resin coating films obviously, slightly improve heat resistance and endows conductive property of the fluorocarbon resin coating films.