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An acrylate emulsion was modified by adding vinyltriisopropoxy silane(trade name C-1706). By adding the multiple emulsifier which consists of an anionic emulsifier,sodium dodecyl benzene sulfonate (SDBS)and nonionic emulsifier,octyl phenolic divinyl oxide(OP-10),the acrylosilane microemulsion was synthesized by seeded emulsion polymerization.The influential factors including the kind and the adding amount of emulsifiers and the monomer variety of alkoxy silane and the added methods which influence on the properties of the microemulsion were investigated.It is found that SDBS and OP-10 as multiple emulsifiers with mass ratio of 1:1 and the adding amount of 2.5%-3.5% can act on co-effect for emulsion polymerization.The C-1706 possesses bulky isopropoxy substituent that can reduce hydrolysis reactivity during the polymerization process,so as to not only make the process smoothly but also advance the store stability of the emulsion. Moreover,the latter-addition mode of C-1706 can restrain its hydrolysis activity and polycondensation reaction during the polymerization process of the emulsion.The structure,the film cross section,the particle size and its distribution of the microemulsion were analyzed by the Fourier Transform Infrared Ray Spectrum(FT- IR),Scanning Electron Microscopy(SEM)and a particle size analyzer,respectively.The results show that the particle diameter of the modified microernulsion can be controlled between 50 and 70 nm and its film hardness is 7.3.Only adding 1.5% of C-1706 into the system of emulsion polymerization can apparently improve the weathering resistance of the microemulsion,which undergo degradation with chromatism(ΔE)is 1.6 after 3 600 hours of QUV-aging.