Synthesis、Modification And The Application In Functional Building Coatings Of Waterborne Polyurethane

In recent years, with the strict control of volatile organic compounds(VOC) in various countries, the waterborne products has got rapid development. In the field of the paint, the waterborne paint has replaced the traditional oil paint increasingly. The water polyurethane(WPU) get much attention by various countries’ researcher due to its excellent performance.The paper used polyester of aliphatic dicarboxylic acids and the isophorone diisocyanate as main raw material to synthesize the WPU. The raw material components and the synthesis condition(like reaction temperature, reaction time, NCO/OH, the additive amount of dihydromethyl propionic acid, the additive amount of the ethidene diamine and stirring speed) were discussed, and so is the physical and chemical properties(like viscosity, NCO content, emulsion particle diameter and film property) of the WPU. The research results show that the best temperature for synthesizing the WPU is: 60-70℃, and the WPU prepolymer response time is 4h; the best NCO/OH(R value) is 2.0; the optimum additive amount of dihydromethyl propionic acid(DMPA) is 1.96wt%; the optimum additive amount of ethidene diamine is 4.0wt%; the optimum stirring speed is 400r/min. Furthermore, through the study of the high pressure microfluidization which can influence the emulsion particle diameter and mechanical property we ensured the feasibility of the improved technology.On the other side, by the base of the detailed studying of the preparation of waterborne polyurethane, the paper used graphene oxide(GOs) to modified the waterborne polyurethane, and by that we got the graphene oxide waterborne polyurethane. By the method of atomic force microscopy and transmission electron microscopy analysis, we found that the modified method was successful and the combination property of the emulsion and film were excellent, and the best GOs content was 1.0wt%. By coordinating the GOs-WPU emulsion with the diatomite and the phase change microcapsule we got the architectural coating. Paint pigments and fillers were determined by orthogonal design, and The addition of emulsion was determined by scanning electron microscope, and then confirm the formula of the coating. By the comprehensive comparison of WPU coating and GOs-WPU coating. Air purification standard test and thermodynamic test results showed that the properties of coating reach top quality goods, and the diatomite in the coating still have many holes which show preferably purifying effect. The potential heat value of GOs-WPU coating could reach 126.1J/g which can reach the result of “peak clipping and valley filling”.