| In this paper, organ-inorganic composite hydrophobic coating was prepared by mechanical blending method. A certain amount of modified Si O2 particles were evenly dispersed in the fluorinated polystyrene solution, and composite hydrophobic coating on glass and silicon were prepared through dipping pulling method. To make the composite surface achieve mass of fluoride group, a coarse surface structure like lotus leaf as well, the proper amount of fluorine monomer and composite proportion of fluorinated polystyrene resin to Si O2 particles were emphatically discussed. This paper can be divided into three parts as follows:Firstly, with styrene(St), butyl methacrylate(BMA), acrylic acid(AA), and fluorine heptyl-meth-acrylate(DFMA) as monomers, AIBN as initiator, toluene as solvent, fluorine modified polystyrene resin were synthesized through solution polymerization. Effect of quality ratio of St to BMA and content of DFMA on water contact angle, hardness, adhesion of fluoride polystyrene resin coating were discussed. Visible light transmittance was characterized by ultraviolet visible spectrophotometer(UV-Vis). Relevant groups were characterized using Fourier transform infrared spectroscopy(FTIR). Thermal gravimetric analysis(TG) was used to characterize the heat resistant properties.Results show that, at 75 ℃, when quality ratio of St to BMA is 3/2, mass content of AA in total monomer is 1.5%, DFMA is 7%, the fluoride polystyrene resin solution coating with a water contact angle of 106.26° on glass substrate can be obtained by impregnating pulling method. Hardness and adhesion are H and 0, respectively. Calculated by the empirical formula, its surface energy is 26.49 m N/m, reducing by 31.28% compare to the coating without modification by DFMA. Using infrared characterization, participating of DFMA in the polymerization reaction was verified. UV-Vis characterization shows that transmittance of coatings are about 87%. Coating remains good thermal stability below 240℃.Secondly, silane coupling agent KH570 was used to modify Si O2 to improve its dispersibility in organic resin. Under the alkaline condition, after hydrolysis and condensation of tetraethyl orthosilicate(TEOS) together with KH570, modified Si O2 were prepared. The effect the amount of KH570 on modification results was discussed. Related groups were characterized by FTIR. Oil-wet coefficient was tested to evaluate the modified results. Modified Si O2 were also characterized using SEM and TG.Results show that, by surface grafting modification with KH570, when the mass content of KH570 is 2%, stablely dispersed Si O2 can be prepared. The oil-wet coefficient was 46.54%. Size analysis of Si O2 particles after modification indicates that the particle size distribution is narrow. Results of FT-IR show that the captain chain groups have been connected to Si O2 surface. SEM images show that, the dispersity of Si O2 was greatly improved. Thermal stability results of TG show that the ideal thermal stability was kept after modification.Finally, adding a certain amount of modified Si O2 to fluoride polystyrene solution, composite hydrophobic coatings on glass were prepared. The influence of mass proportion between fluoride polystyrene resin and Si O2 on water contact angle, hardness, adhesion, and water absorption rate of the coatings were discussed. Effect of water immersion time on water contact angle of composite coating was discussed. The coatings were also characterized by SEM, UV-Vis and TG.Results show that, when the mass fraction of Si O2 particle adding to fluorinated polystyrene solution is 7.41%, water contact angle of the composite coating is 151.21°, rolling angle is about 3°. Hardness and adhesion are HB and 1, respectively. Water absorption rate is 2.53%. After 24 h, water contact angle is 139.85°, falling by 7.51%. SEM images show that the surface has a coarse structure. Transmittance of composite coating C4 is about 70%, and it can keep its shape and properties below 240℃. |
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