Study On The Preparation And Properties Of Nano-particles/Polyurethane Emulsion Modified By Fluoride And Siloxane

With the improvement of environment protection awareness, the green paint with low surface energy has been an important trend of coating development. Polyurethane-polyacrylate(PUA) emulsion has both the advantages in herited from polyrethane(PU) materials such as regards toughness, mar-resistance, elongation and excellent adesion. But the properties inherited from polyacrylate(PA) materials such as hardness and corrosion-resistance, the properties of both materials all determine the poor water resistance of PUA. A kind of fluorinated PUA emulsion with low surface energy and good water resistance can be prepared by adhibiting fluorine with high bond energy and low surface energy. Carbon nanotube(CNT), as a novel material in twenty-first century, was considered to be the most promising candidate as ideal filler owing to its unique structure and particular physical properties.In this experiment, using siloxane-modified WPU as the seeds emulsions, adding three acrylate monomer (fluoride butyl acrrylate, butyl acrrylate, butyl methacrylate) to the seeds emulsions, the composite emulsions were synthesized with core-shell structure. Stability, particle size, water contact angle and water absorption of film coatings of the emulsion are tested. It was studied systemly that the effect of factors such as the reaction temperature, the content of acrylate monomer, the content of initiator, the ratio and content of emulsifier on the properties of emulsion. At the same time, the chemical structure and surface morphology of the film coatings was characted. The research indicates that the properties of emulsion is excellent and the water resistance can be improved with fluoride monomer.On the base of FSiWPUA emulsion, the emulsion of FSiWPUA complexed with nanoparticles was prepared in-situ/polycondensation and blended in solution respectively. It was studied systemly that the effect of factors such as ability of disperse, species and content of the nano-particles on the properties of the emulsions and its film coatings. In order to obtain the compatibility of nanoparticles in the polyrethane and force of interaction, the carbon nanotube functionalezed with poly(lactic acid) and dispersant were used in experiment. The prepared emulsion's properties and water resistance of film coatings are better. At the same time, the chemical structure and surface morphology of the film coatings was characted. The results indicates that the roughness and surface energy of film coating can be improved with catbon nanotubes.