Research Of Preparation Of Super Hydrophbic Self-cleaning Fluorocarbon Coating With Organic Fluorine Resin

1. A fluorinated polyacrylate （DLHM） emulsion was prepared bycopolymerization of dodecafluoroheptyl methacrylate （DFMA）, laurylacrylate （LA）,2-hydroxypropyl methacrylate（HPMA） and3-（methylacryloxyl）propyltri-methoxy silane （MPMS） in the presenceof anionic/nonionic surfactants. The structure and physicochemicalproperties of DLHM were characterized by Infrared spectrum （IR）,1H-nuclear magnetic resonance （1H-NMR） and Transition electronmicroscopy （TEM）. Then the DLHM emulsion was prepared to thefluorocarbon coating with acrylic resin and nano-TiO₂, then effects oftemperature and dosage of emulsion and nano-TiO₂on properties ofcoating were discussed. At last, surface microstructure of coating wascharacterized by Scanning Electron Microscope （SEM）. The experimentresults showed that:（1） DLHM emulsion is of blue appearance, good stability solidcontent of26.8%while the viscosity of0.005Pa·s. The zeta potential ofthe emulsion is-29.04mV and the average size of particles is131nm.（2） When the DLHM emulsion is analysed by TEM, we can seemost of emulsion particles smooth surface like round ball, and part ofthem existing reunion because of hydrolysis of MPMS.（3） The coating displays favorable properties when dosage ofemulsion and nano-TiO₂and curing temperature are45g,9g and160℃,respectively. In this conditions, the surface of coating is smooth, and water tolerance, acid and alkali resistance, pollution resistance are thebest, the contact angle is133°.（4） Fluorocarbon coating is characterized by SEM, find the surfaceof coating with micro-and nano-structures that constitute with irregularmicropore and nano-papilla.2. A core-shell fluorinated polyacrylate（BSL-D） emulsion wassynthesized by semi-continuous seeded emulsion copolymerization ofbutyl acrylate（BA）、 styrene（St） and lauryl acrylate （LA） as core anddodecafluoroheptyl methacrylate（DFMA） as shell in the presence of（NH4）2S2O8as initiator and anionic/nonionic surfactants as mixedemulsifier. Then the emulsion was employed with nano-TiO₂to preparethe hydrophobic self-cleaning fluorocarbon coating. The structure andphysicochemical properties of BSL-D were characterized by Infraredspectrum （IR） and Transition electron microscopy （TEM）, then effectsof temperature and dosage of emulsion and nano-TiO₂on properties ofcoating were discussed, and surface microstructure and ability ofself-cleaning of coating are studying. The experiment results showedthat:（1） BSL-D emulsion particles smooth surface like round ball, andthe latexes possess clear core-shell structures, and that the acrylic resinis white as core while organic fluorine resin is gray as shell.（2） The coating displays best properties and water contact angle onits surface is152°, water absorption is4.23%and favorableself-clearing effect when dosage of emulsion is55%, nano-TiO₂is12%,curing temperature and time is170℃and5min.（3） When characterized the coating with SEM, there is a film oforganic fluorine resin on it, and with clear micro-and nano-structuresand excellent self-cleaning. Its contact angle is better than no BSL-Demulsion and no nano-TiO₂coatings.3. A styreneacrylate emulsion containing fluorine was prepared bysoapfree emulsion polymerization of dodecafluoroheptyl methacrylate（DFMA）, butyl acrylate（BA）、 styrene（ST）、 acrylic acid（AA） and（MMA）in the （NH4）2S2O8（APS） as initiator. Then the emulsion was employed with nano-TiO2to prepare the fluorocarbon coating. Theneffects of temperature and dosage of sodium acrylate, APS and DFMAon properties of emulsion were discussed. The structure andphysicochemical properties of BSL-D were characterized by Infraredspectrum （IR） and Transition electron microscopy （TEM）, and researchthe effects of dosage of emulsion and nano-TiO2on properties ofcoating. The experiment results showed that:（1） The emulsion displays best properties and rate of gel is0.8%,percent conversion is97.1%, water tolerance is longer than168h whendosage of sodium acrylate is12%, APS is1%, reaction temperature is78℃, the emulsion is of blue appearance. The coating displays besthydrophobicity and water contact angle on its surface is113°, waterabsorption is6.4%when dosage of DFMA is25%.（2） Emulsion particles smooth surface like round ball when part ofthem existing reunion, and the latexes possess core-shell structures.（3） The coating displays best properties and water contact angleon its surface is142°when dosage of emulsion is55%and nano-TiO2is12%.