Synthesis Of Fluorinated Polyacrylate Copolymer Emulsion With Different Particle Size And Characterization Of Surface Hydrophobic Properties

In this dissertation, the fluorinated polyacrylate copolymer emulsion of different particle sizes about 30nm,75nm and 210nm were prepared by semi-continuous seed emulsion polymerization method, and methyl methylacrylate(MMA), fluoromonomer and butyl acrylate(BA) were used as monomers. Through the design of core-shell structure and mechanical blending of copolymer emulsion which containing different latex particle sizes, the good surface hydrophobic properties was achieved with lower amount of fluorinated monomer. The influence of the various factors on emulsion particle size of copolymer latex emulsion was also discussed.In the emulsion polymerization of polyacrylate copolymer, the catalytic oxidation-reduction initiation method was used. And it is found that copper sulfate as a catalyst could accelerate the growth rate of free radicals, increasing the number of latex particles and reducing the size of the latex particles, it is an effective way of preparing emulsion of small particle size. By now, there were little reports found focusing on the preparation of small particle size fluorinated copolymer emulsion using catalytic oxidation-reduction initiation method. This paper tried the method to get smaller particle size in the emulsion polymerization of MMA, BA and fluorinated monomer, and the result showed that the expected copolymer emulsion particle size of 30nm could be obtained by this way.Seed latex swelling is the major way to synthesize large particle size emulsion. In this paper, the seed emulsion was prepared by using MMA, BA as monomers, and then the seed emulsion was swelled in the same monomers by multiple times, then reacted with fluorinated acrylate monomers to get larger particle size emulsion. And after each swelling, the size and size distribution was investigated, it's got the result that with 10 times amount of the seed monomer and 3 times swelling, the particle size of more than 200nm was reached, while the particle size distribution coefficient was 0.076, representing nearly monodispersity.XPS and CA were used to characterize the hydrophobic properties of the copolymer surface and the fluorinated acrylic emulsion particle size and distribution was determined by DLS.Through the method of blending different particle sizes of the fluorinated acrylic emulsion with different volume ratio, the effect of the surface roughness on hydrophobic properties of latex film was studied. By changing the latex diameter and the quantity of the two blended emulsions, the latex film with the contact angle of 93°was successfully obtained. The prepared emulsion has good stability and film forming property, and the formed film surface has good lotus effect.