Preparation And Modification Of Sulfonated Waterborne Polyurethane

Waterborne polyurethane is a binary colloidal system in which polyurethane is dissolved or dispersed in water. In contrast to traditional waterborne polyurethane system, environment friendly water has replaced poisonous organic solvent. It not only has the original outstanding properties of the waterborne polyurethane, but also meets people’s needs for protecting environment. So waterborne polyurethane has became the main tendency of polyurethane.In this paper, a series of sulfonated waterborne polyurethane were prepared by prepolymer-acetone method with toluene diisocyanate(TDI), polyester diols(CAPA),1,4-butanediol (BDO) and ethylenediamine sodium sulphonate(A95) as main raw materials. The main contents are as follows:(1) A series of sulfonated waterborne polyurethane were prepared by prepolymer-acetone-method, the effects of the content of A95, molar ratio of-NCO/-OH and the time of chain extend on the WPU emulsion and film were discussed. Experimental results showed that excellent sulfonated WPU were prepared when R value was1.4, the content of A95was4%, chain extension time of A95was20min.(2) Graphene oxide/waterborne polyurethane composites were prepared by mechanical blending. The results showed that graphene oxide/waterbome polyurethane were better with ultrasonic dispersion, the mechanical properties of the composites were improved; the tensile strength of the composites increased first and then decreased, while the elongation at break and water absorption gradually reduced with the addition of GOs contents; the thermal stability of GOs/WPU composites was significantly improved by addition of GOs.(3) Nano-silica were prepared by the sol-gel method, then they were modified by KH-550. The results showed that the dispersion of the modified nano-SiO2was better, water resistance of WPU films was improved with modified SiO2. When the addition of modified SiO2was2%, the comprehensive properties of the composites were better.