Preparation And Properties Of Soybean Oil-Based Sulfonic Acid Waterborne Polyurethane

Polyurethane materials have been widely used in building materials,household goods,textiles,leather and medical fields due to their good mechanical properties,excellent weather resistance and elasticity.In recent years,with the emphasis on environmental protection and production safety,the research and development of polyurethane material water-based has become the focus of attention.However,a single water-based polyurethane is slightly insufficient in performance compared with a solvent-based water-based polyurethane due to limitations in the raw material itself and structure,thereby limiting its application.Therefore,in order to expand its application range,people try to modify it to improve its performance in some aspects.This paper mainly uses soybean oil as raw material to prepare soybean oil-based polyol,and then reacts with homemade sulfonic acid type hydrophilic chain extender and isocyanate to form soybean oil-based sulfonic acid type waterborne polyurethane,which is then modified and the properties of the modified waterborne polyurethane were studied.The main research content is divided into three parts:The first part is toluene diisocyanate(TDI)and homemade soybean oil based polyol(MESO),sulfonic acid type hydrophilic chain extender 2,2-dimethylolpropionyloxypropane sulfonate(DMPPS-Na)as the main raw material,the sulfonic acid type aqueous polyurethane emulsion was successfully prepared by acetone method and characterized by infrared spectroscopy.Then,by comparing the appearance of the emulsion and the stability of the centrifugal stability,the optimal synthesis conditions of the aqueous polyurethane were determined as follows: the prepolymerization reaction time was 4h,the reaction temperature was 80°C,the emulsification temperature was 25°C,and the chain extension was carried out post-chain extension.By investigating the influence of R value and DMPPS-Na content on the performance of waterborne polyurethane,the optimal R value was 1.2 and the DMPPS-Na content was 9.8%.At the same time,the properties of waterborne polyurethane emulsion and film were studied by viscosity test,particle size test,surface water contact angle test,mechanical property test and thermogravimetric analysis.The second part is the use of flame retardant FRC-6 modified waterborne polyurethane to improve the flame retardant properties of waterborne polyurethane,and the flame retardant modified waterborne polyurethane is synthesized by acetone method.The effect of the content of FRC-6 on the properties of modified waterborne polyurethane was discussed.The experimental results show that the thermal stability and flame retardancy of the modified waterborne polyurethane are obviously improved,and with the increase of FRC-6 content,the water absorption of the waterborne polyurethane film increases first and then decreases.The tensile strength decreases first and then increases.When the FRC-6 content is 20%,the limiting oxygen index is increased from 18% to 24.3% compared with the unmodified waterborne polyurethane.The amount of residual carbon after combustion increases from 7.96% to 9.68%,with a growth rate of 21.6%.The third part is to modify the waterborne polyurethane with fluorosiliconeoil(PTFPMS)to enhance the water resistance of the waterborne polyurethane.By blending PTFPMS with aqueous polyurethane prepolymer,the PTFPMS modified waterborne polyurethane was synthesized.The effect of the content of PTFPMS on the properties of waterborne polyurethane was discussed.The experimental results show that the water-resistance and surface water contact angle of the modified water-based polyurethane are significantly improved.When the PTFPMS content is 4%,the surface water of the film is compared with the unmodified waterbased polyurethane.The contact angle increased from 76° to 92.5°,and the water absorption decreased from 14% to 7.02%.And with the increase of PTFPMS content,the tensile strength of waterborne polyurethane film increases first and then decreases.When the content of PTFPMS is 4%,the maximum value is reached,tensile strength increased by 67.9% compared to unmodified film,while the elongation at break first decreases and then increases,and the thermal stability is also improved to some extent.