Preparation And Characterization Of Sulfonated Waterborne Polyurethane

Waterborne polyurethane(WPU), dispersed with water instead of organic solvent, has attracted increasingly attention due to its excellent performance, as more strict requirements of environental protection and enhanced environment protecting consciousness. Over the20years, as extended and used, a great variety of waterborne polyurethane products have been successfully applied in the area of light textile, printing and dyeing, leather, wood processing, building, papermaking and so on. At present, waterborne polyurethane of high performance, low cost and wide field is researching and developing. But it is very hard to obtain carboxylic waterborne polyurethanc of high solid content and high performance, as the weak acidity and the defective hydrophilic ability of carboxyl group. By contrast, it is appropriate for preparing sulfonated waterborne polyurethane of high solid content and high performance by adding a little sulfonate, as its better hydrophilic ability.Also, white preparing sulfonated waterborne polyurethane, no neutralizer is added, which has volatility and irritant smell of samine. Moreover, sulfonated waterborne polyurethane has become a hot issue in this area due to its good drying and film formation, coating and process ability,, water disperse and stability.In the first chapter, the technique of sulfonated waterborne polyurethane application and research process are introduced, respectively, with preparing the sulfonated waterborne polyurethane dispersion as the main cluess. Research process of air-dry waterborne polyurethane and waterborne polyurethane modified with organic gilicon, together with modification mechanism and development tendency are also introduced.In the second chapter, The preparation of waterborne polyurethane with a soft segment containing sulfonic acid group was introduced, A waterborne polyol was prepared with the poly condensation of dimethy1-5-sulfoisophthalate sodium salt (SIPM)、hexanedioic acid(HA) and neopentyl glycol(NPG). And then, polyurethane prepolymer was prepared by react the obtained polyol with isophorone diisocyanate (IPDI). Finally The prepolymer was dispersed under vigorous agitation by adding water and by chain extension with1,4-butanediol(BDO) and Tri--methylol propane (TMP). The results indicated that the high content of the waterborne polyurethane dispersions up to50%、average particle size of24.83nm and high crystallinity was obtained. Infrared spectroscopy (IR), proton nuclear magnetic resonance spectroscopy (’H-NMR) were characterized by the structure of the polyester polyol and water-based polyurethane, The result consistent with the theoretical structure synthesis, A waterborne polyol having a Number-average Molecular Weight of980and Weight-average Molecular Weight of1248was characterized by Gel Permeation Chromatography (GPC), particle size analyzer measured the average particle size of the water-based polyurethane was24.83nm, The results show that the synthesis of Sulfonated waterborne polyurethane was a stable emulsion dispersion, Thermal gravimetric analysis(TG) and wide-angle X-ray diffraction (XRD) characterization results indicate that the preparation of sulfonated waterborne polyurethane has a high heat resistance and crystalline.In the third chapter, The method of preparation of an air-dry Waterborne Polyurethane Dispersions was introduced, that is used linolic acid containing active methylene group to modified sulfonated waterborne polyurethane. A prepolymer was prepared by reacting the obtained polyester polyol with isophorone diisocyanate and a mixture of linolic acid ester polyol synthesized by esterification reaction of trimethylolpropane (TMP) and linolic acid as the raw material. An air-dry waterborne polyurethane dispersions was preparation with a mixture of linolic acid ester polyol containing dry oils group as a chain extender to lead into polyurethane prepolymer and then Cross-linked disperse in water. The structures of the result polymer were characterized by Fourier transform-infrared (FT-IR) spectroscopy; the properties of cast film were measured by thermal gravimetric analysis (TGA), tensile tests and water resistance tests. Finally The results indicated that The cast film exhibits good mechanical properties、thermal stability and good water resistance.This air-dry waterborne polyurethane could cross linked at room temperature, and the drying rate has been markedly improved.In the fourth chapter, A prepolymer was prepared by reacting the obtained sulfonated polyester polyol with isophorone diisocyanate (IPDI) and tri methylolpropane (TMP). The seed emulsion containing vinyl and silicone prepared by method of end capping with bi-functional monomer (3-hydroxyethyl methacrylate (HEMA) and modification by silicone coupling agent y-amino-propyl triethoxysilane (KH550). The silicone modified sulfonated polyurethane/poly acrylic composite emulsion was obtained with copolymerization by mixture monomers Methyl methacrylate (MMA) and butyl acrylate (BA). The performance of the composite emulsion and film analysis and characterized by means of infrared spectrum (IR), transmission electron microscopic (TEM), thermo gravimetric analysis (TGA), and X-ray diffraction analysis (XRD). The Results Showed That core-shell structure had formed between polyurethane and acrylate. After modified by silicone and acrylate, the thermal stability, water resistance, mechanical properties of polyurethane was improved obviously.