Synthesis And Characterization Of Fluorined Acrylate Copolymer Emulsion

Emulsion polymerization is a reaction system which has good-heat-transference, high-rate of polymerization, big-molecular weight, low-viscosity and at the same time environmental friendly. Therefore, its product is widely used in adhesive, painting, rubber, drug carrier etc.Fluorinated acrylic polymer emulsion combines excellent film forming properties, mechanical properties of acrylic polymer emulsion and high weather resistance, high stability, and water/oil repellent properties of fluoropolymers. Thus, it has gained increasingly interest in textile treating, antifouling coatings, leather, architecture, fiber optics and other fields.Fluorinated acrylate copolymer is composed of long perfluorinated side chains, main chain of the polymers and other groups. Researches show that when n^8, the fluorinated alkyl(CnF2n+i) in the perfluorinated chains can easily generate to perfluorinated octyl sulfonyl compounds and perfluorinated octylic acid compounds in natural environment, which have potentially carcinogenic effect after long-term accumulating in human or animals’ bodies. So we pay more and more attention on developping the fabric finishing agent which has a short fluorocarbon chain and is easily biodegraded. In this work, there are three main contents:Firstly, we synthesized a functional monomer2-[(2-hydroxyethyl) sulfonyl] ethyl acrylate and2-(perfluorohexyl) ethyl acrylate. In the emulsion polymerization, we used PFHEA、SA and functional monomer as polymerization monomers, a compound emulsifier, using persulfate as initiator, together with moderate amount cosurfactants、chain transfer agent and deionized water. To get a stabilized pre-emulsion, we first carried out1h high-speed stirring and30min ultrasonic emulsification. We took out part of the pre-emulsion and heated it to50-90℃, kept the temperature for0.5-1h to get a blue-fluorescence emulsion. Then added the remaining pre-emulsion and the remaining initiator, kept the temperature for3-6h. Afterwards, lower the temperature and adjusted the pH to get a ternary copolymer emulsion. Secondly, to get a stabilized pre-emulsion, using PFHEA、SA、BA and HEA as raw material, a compound emulsifier, together with moderate amount cosurfactants、 chain transfer agent and deionized water, we carried out high-speed stirring and20-60min ultrasonic emulsification.Put the initiator APS soluble in water, used as a solution.Bubbled N2into the three-round bottom flask which equipped with a reflux condensing tube、 a thermometer、 a constant voltage dropping funnel. Added1/2pre-emulsion and1/3initiator solution, heated to80℃. Drop the remaining pre-emulsion and the remaining initiator to the bottom when blue fluorescence appeared. Finish the dropping in2-3h and keep the temperature for4h. Low the temperature to40℃and adjust pH to7. Then we got ivory aqueous fluorinated acrylate quaternary copolymer emulsion with blue fluorescence.Thirdly, we got a reasonable reaction condition by testing the polymerization temperature、reaction time and feed methods. We characterized the polymer structure by FT-IR、1HNMR、19FNMR. The polymer thermal properties and molecular weight were characterized by TGA、DSC、GPC. We determined emulsion particle diameter、 morphology、stability and the contact angle of film-forming.