| The polymer contained repetitive carbamate was called polyurethane. It was produced by the reaction of polyisocyanate and polyol (compound containing an active hydrogen). Waterborne polyurethane means that polyurethane particles are dispersed in a binary colloidal system in water. It has the advantage of eco-friendly, nontoxic, energy saving. It was used in the field of coating, textile finishing, foam, adhesive and so on. But its applications were restricted because of its poor thermal stability and water resistance, and low solid concentration. So there are many researchers modified polyurethane to improved its physical and chemical properties.The highest electronegativity and the smaller atomic radius endow the organic fluorine compound special physical and chemical properties. The fluorine atoms in the main chain of perfluorocarbon alkylation link spirally along the carbon chain. The organic fluorine compound has excellent thermal stability and chemical inertness because of the helical structure. The C-F bond is short, and it has an excellent stability. This property endow the organic fluorine compound low friction and viscosity and good water and oil resistance.Si-O-Si bond is length, bond angel is big. So the structure of the organic silicon compound is helical. The main chain is soft. The interaction force and surface tension are small. The organic silicon compound can be used between-50℃to200℃. The bond energy of Si-O was lager, so the organic silicon compound has the properties of thermal stability and insulativity.There are many substance used to modify polyurethane, including epoxy resin, organic fluorine, organic silicon, acrylate. There are many research about the polyurethane modified by organic fluorine or organic silicon, but there are little research modified the polyurethane by both compounds. So the research of polyurethane modified by fluorine and silicon has far-reaching significance. The experiment consisted of the following part:1.Perfluorinated Hexyl Diol was synthesized by 3-Perfluorohexyl-1,2-Propylene Oxide and methylamine. The optimum reaction conditions were determined by orthogonal test. The ratio of3-Perfluorohexyl-1,2-Propylene Oxide and methylamine is1:20; The temperature and time of two steps are25℃,8h and65℃,15h. Polyether polyurethane modified by organic fluorine and silicon of different fluorine and silicon content was synthesized by isophorone diisocyanate, perfluorinated hexyl diol, ethidene diamine as the hard segment, dimethylol propionic acid as the hydrophilic chain extender, triethylamine as the neutralizer, PTMG and hydroxyl silicone oil as the soft segment.2.The property of polyether polyurethane was characterized by FT-IR, TGA, DLS, GPC, EDS, contact test. The result showed that with the increase of fluorine content, the particle size and contact angle were increased, the thermal decomposition temperature was rose. The spectrogram of EDS showed that the content of fluorine and silicon in the polymer coating were greater than the theoretical content. This illustrated that fluorine and silicon were migrated to the surface in the film-forming process. The result showed that when the content of fluorine was8%, the silicon content was7%, the polymer coating had the best property.3. Polyethylene glycol ester of adipic acid was synthesized by adipic acid and glycol. The acid value and hydroxyl value were used to confirm the molecular of the polymer. Then polyester polyurethane modified by organic fluorine was synthesized by isophorone diisocyanate, perfluorinated hexyl diol, ethidene diamine as the hard segment, the polyester diol as the soft segment. The property of polyester polyurethane was characterized by FT-IR, TGA, DLS, GPC, EDS, contact test. The results showed that the polyurethane modified by organic fluorine had excellent hardness, water and heat repellency, and acid-base resistance property. |
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