Design, Synthesis And Application Of Waterborne Polymer Antifouling Coatings

Anti-smudge coating,one kind of new-emerging functional coating,developed in recent years,becomes compromising for its low surface energy to repel smudge and to keep the substrates surface clean.As a consequence,its extensive use would maintain environment so clean as to save more time and cost.Noticeably,the waterborne paint features environmental-friendliness and safety,which makes the development of waterborne anti-smudge coating more urgent and significant.Polyacrylate,famous for the advantage of anti-weathering,high decorativity and excellent mechanical robustness,if fluorine-containing segments were introduced,would outstandingly provide coating with excellent water-and-oil repellency due to its low surface energy.For the reasons above,two kinds of waterborne plolyacrylate,anionic one and cationic one,were synthesized and then modified with poly(perfluoropropylene oxide)glycol derivatives(PFPG)to investigate its anti-smudge properties and respective advantages inherent in two systems,which would finally provide basic grounds for its further application.Waterborne anionic polyacrylate was prepared via free radical polymerization by the use of methyl methacrylate(MMA),butyl acrylate(BA),acrylic acid(AA)and hydroxypropyl methacrylate(HPMA)as basic monomers.HDIT was used as crosslinker.Suitable particle size of dispersion and resultant coatings with excellent properties,that 3H hardness,0 level adhesion,1 mm level bending,50/50 kg.cm impact resistance,were obtained from the experimental condition that glass transition temperature(Tg)was 10℃,with HPMA contents of 20 wt%,and AA contents of 7wt%.On the conditions above,different weight ratios of PFPG(with respect to polyacrylate)were added for modification.When 1.0 wt% PFPG was added,the contact angles of water,diiodomethane and hexadecane were 107.0°,89.0 ° and 65.0°,and the rolling angles were 57.5°,9.1° and 13.5°,respectively.After being immersed in soy oil and pump oil,the coating retained extreme oil repellency,and the oil used slid away from coating without leaving noticeable traces,showing its excellent anti-smudge and self-cleaning ability.Applied on different substrates such as tin plate,wood,paper and glass,the coating demonstrated excellent anti-smudge performance as well,showing its wild applications on various substrates and suggesting that it could be further used to the protection of precious paintings,anti-fingerprint screens and other decorativity-oriented commercial products.In addition,other tests such as bending,impact,adhesion,anti-wearing,corrosion resistance and anti-weathering were investigated and both of them shown good results.However,because the crosslinker HDIT has multiple-NCO groups,groups that easily react with OH-containing polymer,thus the resultant mixed aggregate is limited by time to use.Waterborne cationic polyacrylate,which was used for electrophoresis deposition stratedge,was prepared via free radical polymerization by using methyl methacrylate(MMA),butyl acrylate(BA),dimethylaminoethyl methacrylate(DMAEMA)and hydroxypropyl methacrylate(HPMA)as basic monomers.BHDIT was used as crosslinker.Good storage stability of dispersion were obtained under certain condition that Tg was 10℃,with HPMA contents of 15 wt%,DMAEMA of 12 wt%.When the applied time was 50 s and the applied voltage was 30 V,the uniform transparent coating with 2H hardness,0 level adhesion and 1 mm level bending was obtained.On the conditions above,different weight proportions of PFPG(with respect to polyacrylate)were added for modification.When 1.0 wt% PFPG was added,the contact angles of water,diiodomethane and hexadecane were 112.5°,91.9° and 69.8°,and the rolling angles were 45.2°,8.1° and 12.0°,respectively.After being immersed in soy oil and pump oil,the coating retained extreme oil repellency,and the oil used slid away from coating without leaving noticeable traces,showing its excellent anti-smudge and self-cleaning properties.In addition,other tests such as bending,impact,adhesion,anti-corrosion and anti-weathering on anti-smudge coating were investigated and both of them shown good results.Cathodic electrodeposition paint features its environmental-friendliness,safeness,high utilization rate,controllable thickness,good coating efficiency,and it could be applied for conductive substrates with complicated shapes but not for non-conductive ones.