Research Of Fluorinated Acrylate (Polyurethane) Copolymer Latex Under Microwave Radiation

Fluorinated copolymer emulsion, mainly prepared by emulsion polymerization of fluorine monomer and vinyl monomer, is the film-forming material and main components in water-based fuoropolymer coatings. And fluorinated acrylic polymer emulsion is one of the main categories. Fluorinated acrylic polymer emulsion combines the excellent film forming properties, mechanical properties of acrylic polymer emulsion and high weather resistance, high stability, and water/oil repellent properties of fluoropolymers. As a result, it has gained increasingly interest, applied in coatings, textile treating, leather, architecture, fiber optics, microelectronics and other fields.With the in-depth study of fluorinated acrylic polymer emulsion, it was found that the ordinary fluorinated acrylic polymer emulsion has some shortcomings like hot sticky cold crisp, and its mechanical properties cannot meet the requirements in many areas of application. By introducing the cross-linking reactions, we can make the membrane cross-linked to form three-dimensional network structure, and further improve the coating's chemical resistance, stain resistance and mechanical properties. In the emulsion polymerization process, the use of microwave irradiation has the several advantages over conventional heating, such as high conversion rate, low energy consumption, pollution-free and so on.In our work presented here, room temperature self-crosslinkable fluorine-containing acrylate polymer emulsion was prepared through emulsion polymerization with dodecafluoroheptyl methacrylate as the fuorine-containing monomer, diactone acylamide as functional monomer, SDS/OS-15 complex as emulsifier and KPS as the initiator. FT-IR and 'H-NMR spectra were used to determined the structure of the copolymer; the impact of the amount of emulsifier, the amount of crosslinking monomer and the amount of fluorinated monomer on the latex particle size were studied by laser light scattering particle size analyzer (PCS) of impact; the morphology of the latex particles were observed by transmission electron microscopy (TEM); and the stability of emulsion and water absorption of latex films were studied. FT-IR and'H-NMR spectrum showed that the fluorinated monomers, crosslinking monomers, acrylic monomers are involved in the copolymerization. The results showed that when the content of fluorinated monomer, crosslinking monomer and emulsifier is 25%,5%and 5%, respectively, the microwave irradiation condition is 700W and 72℃, the obtained emulsion is stable and the water absorption of the film is low.In addition, by combining the advantages of water-based polyurethane and fluorinated acrylate, we can obtain water-based resin materials with significant properties. In the second part of this work, anionic polyurethane emulsion was first obtained and applied as seed emulsion, and then fluorine-containing acrylate monomers and acrylic monomers were added to polymerize and obtained core-shell complex emulsion. When the concentration of the hydrophilic monomer and fluorine-containing monomer is 6% and 30%, respectively, the obtained emulsion owns high stability and the water absorption of the membrane decreased significantly, with the water and solvent resistance improved markedly.