Studies On Waterborne Polyurethane Based On Sulfonate

As an environment-friendly of applied polymer materials, the waterborne polyurethane（WPU）, not only has wear-resistant, resistant in low temperature, good toughness like thegeneral resin, but also has other advantages like non-combustible, non-toxic, tasteless,energy-saving and so on. Among them, the sulfonated WPU with good stability, heatresistance and non-environmental pollution has quickly become the hot spot of the WPUfield. Therefore, in using homemade N-（2-aminoethyl）-2-aminoethane sulfonate （AAS）as sulfonic acid type hydrophilic chain extender, we prepared series of WPU latex andmodified WPU latex. Specific content includes:（1） The target product, ethylenediamine sodium sulfonate, is synthesized fromethylenediamine and sodium2-chloroethane sulfonate. The optimum time, temperature, pHvalue and feeding methods of the reaction was analysised in detail. The products arecharacterized by FT-IR,¹H NMR,¹³C NMR. Analysis of each element content in productsis the detection method to determine the optimum synthesis conditions of the article. XRDanalysis result shows that the product is a kind of good crystalline compounds. In addition,the solubility of the product is analyzed.（2） The sulfonated waterborne polyurethane with solid content at50%aresynthesized by using the prepolymerization process, with using PBA) as softsegment, HDI and IPDI as hard segment, self-made AAS as hydrophilic chainextender. The influence of nHDI/nIPDI and AAS content in WPU on the stability,viscosity, morphology, particle size distribution of WPU emulsion and the waterresistance, heat resistance, mechanical properties of WPU films are discussed indetail. The studies have shown that the best nHDI/nIPDI is2.0and the content ofAAS is at1.16%.（3） The single WPU is poor in water resistance and mechanical properties. Therefore,the epoxy resin （E-20） which has high mechanical strength, chemical stability and thermalstability is used to modify the single WPU in this article. The results show that the modifiedWPU has excellent appearance, latex viscosity, high mechanical properties, heat resistanceand water resistance when the content of E-20is3%. DSC curves show the compatibility inE-20and the hard segment molecular chain of the WPU is better.