Preparation And Property Of Polyurethane/Polyacrylate Composite Emulsion

Waterborne polyurethane has excellent cold endurance, flexibility, abrasion resistance, being ease of use, pollution-free, but has these disadvantages in water resistance, light resistance. Modified waterborne polyurethane can improve the performance of polyurethane. Polyacrylate has some advantages such as good water resistance, chemical resistance. The property of PU and PA are complementary, therefore a combination of polyurethane and polyacrylate play their respective advantages so that the film emulsion and the performance improved significantly. New latex combined with polyurethane and polyacrylate is the research focus home and abroad.In this paper, polyurethane/polyacrylate (PUA) composite emulsion was synthesized by method of core-shell polymerization. At first, we synthesize waterborne polyurethane, and then modify it with acrylate. At last, we get polyurethane/polyacrylate (PUA) composite emulsion with obvious core-shell structure.To synthesize stable PUA composite emulsion of good performance, the content of acrylate monomers, NCO/OH molar ratio (R), the content of DMPA, the content of composite emulsifier, the content of NMP which as thinners of the emulsion and other factors on emulsion and film performance were studied. We also compared the two methods and the effects of different feed modes on the preparation and properties of PUA emulsion were studied. The optimal raw material selection and reaction formulation and the optimal process conditions of preparation of PUA emulsion were obtained.Fourier transform infrared spectroscopy (FTIR), GPC were used to analyze structure and molecular weight, observation of the appearance and test of the storage stability were used to analyze the appearance of stability, laser tablets Analysis, transmission electron microscopy (TEM) were used to analyze particle size, particle size distribution and morphology, test of conversion, solid content, the contact angle and water absorption were used to analyze the emulsion and coating performance; The results indicate that: the method of in-situ emulsion polymerization is more stable and better, the emulsions synthesized by both were of core-shell structure.