Synthesis And Properties Of A Hard And Ambient Curable Environmental Self-cleaning Coating

The glass walls,automobiles and other outdoor surfaces are easy to be contaminated by pollutants and acid rain.Cleaning these outdoor surface need cost a lot,so the hydrophobic coating can be widely used in the fields of construction,transportation and national defense.Because of the strong corrosion resistance,weather ability and low surface energy,polysiloxane were often used as raw materials for preparing the hydrophobic coatings.In this paper,we studied a hydrophobic and hard coating which can be used for outdoor surfaces.The hydrophobic coatings had high surface hardness,good hydrophobicity,strong adhesion,anti-aging and corrosion resistance and room temperature curing.The effects of siloxane species and content,water content,and polymerization condition on the properties of coating were investigated.The hard and hydrophobic coating was prepared under the optimum conditions.The main conclusions are as follows:The sol-gel dipping process,using tetraethoxysilane,dimethoxydimethylsilane,glycidyloxypropyltrimethoxysilane,methyl trichlorosilane and methyltriethoxy silane as precursor,oligomer sols were formed under acidic conditions.The properties of hydrophobic coatings were affected by the content of water and dimethoxydimethylsilane,reaction temperature.The static contact angle of the prepared coating is 65°.The hardness of the coating reached 2H.The adhesion of the coating reached 1.The transmittance of the coating was close to the glass substrate.The coating can be cured at room temperature for a short time.Nano-SiO₂ was widely used as a reinforcing material to improve the properties of composite materials.Nano-SiO₂ was dispersed by ethanol,isopropanol and other solvents.The prepared polysiloxane sol was mixed with silica dispersion to prepare composite coatings.The prepared polysiloxane sol was mixed with SiO₂ dispersion to prepare composite coatings.The effect of the amount and concentration of dispersion on the properties of the coatings was studied.The static contact angle of the composite coating is96°.The hardness of the coating reached 8H.The adhesion of the coating reached 0.The transmittance of the coating was 78%.The coating can be cured at room temperature for a short time.Fluoro-siloxane possessed better properties of low surface energy,anti-aging and corrosion resistance.Fluoro-siloxane was widely used in coating,adhesives and other fields.Fluoro-siloxane was used as the reactant to improve the hydrophobicity of the coating by reducingthesurfaceenergyofthecoating.?Heptadecafluoro-1,1,2,2-tetradecyl?trimethoxysilane?FAS?and kinds of siloxane hydrolyzed used acidic conditions.A series of solvents were prepared by controlling the content of FAS.The static contact angle of the composite coating is 110°.The hardness of the coating reached 3H.The adhesion of the coating reached 0.The transmittance of the coating was 68%.The coating can be cured at room temperature for a short time.The prepared polyfluorosiloxane sol was mixed with Si O₂ dispersion to prepared composite coatings.The effect of the amount of dispersion on the properties of composite coatings was studied.The static contact angle of the composite coating is 115°.The hardness of the coating reached 9H.The adhesion of the coating reached 0.The transmittance of the coating was 79%.The coating can be cured at room temperature for a short time.Four kinds of coatings were tested for corrosion resistance.The prepared coatings had the properties of anti-corrosion.The aging process of the coatings accelerated by ultraviolet treatment.The anti-aging ability of the coatings was illustrated by comparing the properties of the coating after aging.