Preparation And Properties Evaluation Of Water Repellent And Inflaming Retarding Waterborne Polyurethane

Water repellent waterborne polyurethane was prepared by self-emulsification method and bulkpolymerization, the main research discussed the influence factors on properties of anionicwaterborne polyurethane which included the kinds of soft monomer and hard monomer, theproportion of n-NCO/n-OHof prepolymerization, the isocyanate index, the blocking degree, theanion content, the neutralization degree, the dosage of cross linking monomers, the dosage oforganic silicon, the dosage of hydroxyl-terminated polybutadiene and the introduction of organicfluorine. The various performance of water repellent waterborne polyurethane emulsion(including dilution stability, electrolyte-resistant stability, centrifugal stability and the resistance toacid and alkali stability and so on), and the properties of water repellent waterborne polyurethanefilm were tested. The synthetic products were analyzed and characterized through the laserparticle size test, the Fourier transform infrared spectroscopy (FT-IR), the static contact angle andso on. Then using the prepared water repellent waterborne polyurethane blended with flameretardant, and testedthe flame retardant property.The results showed that the kinds of soft monomer and hard monomer, the proportion ofn-NCO/n-OHof prepolymerization, the isocyanate index, the blocking degree, the anion content, theneutralization degree, the dosage of cross linking monomers, the dosage of organic silicon, thedosage of hydroxyl-terminated polybutadiene and the introduction of organic fluorine hadsignificantly influence on properties of waterborne polyurethane emulsion and film. Using mixedpolyether could improve the water resistance of waterborne polyurethane, elasticity and handle.Introduction of cross-linking monomer could improve the mechanical properties of thewaterborne polyurethane film. The hydrophilic chain extender dihydroxy methyl butyric acid hadgood effect in the synthesis of waterborne polyurethane which compared with dihydroxy methylpropionate. The proportion of n-NCO/n-OHof prepolymerization, the isocyanate index, the blockingdegree, the anion content, the neutralization degree, the dosage of organic silicon, and the dosageof hydroxyl-terminated polybutadiene should be not exorbitant, otherwise it would influence onthe performance of the waterborne polyurethane emulsion and film. The introduction ofhydroxyl-terminated polybutadiene, organic silicon, and organic fluorine could greatly improvethe waterproofperformance ofthe waterborne polyurethane.The main research results are as follows: Using the Fourier transform infrared spectroscopy(FT-IR) analysis shows that successful synthesis of waterproof waterborne polyurethane. By thelaser particle size analysis, the average particle size of water repellent waterborne polyurethaneemulsion is about540nm, and has narrow particle size distribution. Through the propertiesevaluation of water repellent waterborne polyurethane emulsion and film, finding the optimumsynthesis process of water repellent waterborne polyurethane is: the proportion of n-NCO/n-OHofprepolymerization is5.15, the isocyanate index is1.09, the blocking degree is60%, the anion content is5.56%, the neutralization degree is110%, the dosage of cross linking monomers is10.22%, the dosage of hydroxyl-terminated polybutadiene is8.75%, the dosage oforganic siliconis17.95%. The burning-resistance coating finish is applied on the fabric with waterproofwaterborne polyurethane and flame retardant blended compound, which can improve the flameretardant propertyof fabric well.