Synthesis and Characterization of Fluorinated Acrylate Emulsion with Core-Shell Structure

The fluorinated acrylate copolymer emulsion with core-shell structure was synthesized by a multi-step seed emulsion polymerization,in which methyl methacrylate(MMA),butyl acrylate(BA) and hexafluorobutyl methacrylate(HFMA) acted as main monomers and fluorine-containing monomer respectively.Fluorine-containing acrylate emulsion with soft core/hard shell was formed,in which the emulsion particle average size was 120 nm and the film water absorption was 7%,when m(MMA)∶m(BA)=45∶55,m(core monomer)∶m(shell monomer)=6∶4,and w(HFMA)=7% and w(compound emulsifiers)=3%～4%(based on total monomers).The emulsion and their films were characterized by FTIR,DSC and TG.The results show that HFMA is effectively involved in the copolymerization,the synthesized polymer emulsion has two glass transition temperatures(Tg1=-10.2 ℃ and Tg2=58.4 ℃),and the temperature of decomposition is increased by 59 ℃.The contact angle of emulsion film with water is 98.2°.Fluorine is concentrated on the surface of the shell,and the film thermal stability and water resistance are improved greatly.