Synthesis And Properties Of Green,Red And Purple Waterborne Polyurethane Dyes

As a new type of polyurethane chain extender,small-molecule colored monomers are embedded in the molecular chain of water-based polyurethane,and the polymer dyes we need are obtained through chemical synthesis.Traditional dyes often have shortcomings that are difficult to solve,such as poor heat resistance,cumbersome preparation processes,and environmental pollution by waste water.In order to meet the needs of the safe,efficient and green market and people,we synthesized waterborne polyurethane dyes of different colors through chemical bonding.Because of its excellent photochromic properties,it has been widely used in biology and medicine and other optical fields and has attr acted widespread attention.Photochromic polymer dyes can overcome a series of shortcomings of many traditional photochromic small molecule dyes,such as absorption rate,low fixation rate,too fast migration speed,poor color fastne ss,and poor affinity.In recent years,various polymer dyes including polyester,polystyrene,polyacrylonitrile and polymethyl methacrylate dyes have been pro duced.But they have a common disadvantage that most of them are solvent-b ased polymers,which can cause serious environmental problems when used.Ho wever,waterborne polyurethane is a versatile and environmentally friendly mate rial,which gradually meets the high demands of the market and people.Photo chromic waterborne polyurethane-based dyes have received enthusiastic attention due to their versatility,non-toxicity and environmental friendliness.Some phot ochromic waterborne polyurethane-based dyes have been reported.However,mo st of the research focuses on chemical synthesis and photochromism,while ignoring the dyeing properties.The global demand for polyurethanes(PUs)continue s to grow,which means that polymer materials occupy a major market.In fact,polyurethane is used to produce different forms of materials(adhesives,foams,elastomers,etc.)not only in the automotive industry,but also in the construction industry.This article mainly uses the active groups in the small molecule dyes to partially replace the traditional polyurethane chain extenders,and prepares water-based polyurethane emulsions with different luminescence properties,including aminofluorescein polyurethane materials that emit green fluorescence and alizarin that emits purple fluorescence Plain polyurethane materials and blue 60-emitti ng polyurethane materials,which polymerize and water-based small-molecule dyes,make them environmentally friendly materials.In addition,we used infrared spectroscopy,ultraviolet spectroscopy,hydrogen NMR spectroscopy,and other methods to characterize its structure,and studied the luminescence properties of blue waterborne polyurethane and purple fluorescent waterborne polyurethane,as well as the application possibilities in fabric dyeing.The main work of the thesis:(1)Firstly,the amino fluorescein is prepared by the traditional melt-reducti on method,and then the amino fluorescein is introduced into the polyurethane chain by the acetone method.The structure characterization of the infrared spectrum and the ultraviolet spectrum proves that the amino fluorescein polyurethane has been successfully synthesized,We found that when AF molecules are introduced into polyurethane,there is a certain increase in thermal stability at high temperatures.In some fluorescence tests,we have concluded that AF-WPU emits green fluorescence.And under the change of temperature and concentration,the fluorescence will change to a certain extent.When the temperature gradually increases,the fluorescence intensity decreases.When the concentration changes,the fluorescence intensity will first increase and then decrease.Meet our expectations.(2)Through the introduction of alizarin(AH)into the polyurethane chain,the red spectrum and ultraviolet spectrum and other structural characterizations proved that the alizarin polyurethane has been successfully synthesized,which proved that the AH small molecule monomer was successfully introduced into In the polyurethane chain,after passing the DSC and TGA thermodynam performance tests,we found that with the increase of the amount of AH,the modynamic properties of the polymer have been significantly improved,and in the results of the fluorescence test,it is found that AH-WPU emits Red fluorescence and the fluorescence will change to a certain extent under the change of temperature and concentration.When the temperature gradually increases,the fluorescence intensity decreases.When the concentration changes,the fluorescence intensity will first increase and then decrease.Meet our expectations.(3)A series of disperse blue polyurethane emulsions were prepared.Structural characterizations such as infrared spectroscopy,hydrogen nuclear magnetic spectroscopy and ultraviolet spectroscopy proved that the dispersion blue polyurethane emulsions had been successfully synthesized,which proved that the dispersed blue monomer was successfully introduced into the polyurethane.In the chain,dispersed blue polyurethane emulsions(DB)with different proportions were prepared.Compared with DB+WPU,the ultraviolet-visible spectrum of DB60-SWPU has an obvious low color shift of 61 nm fluorescence intensity,and the fluorescence intensity is obviously enhanced.In the fluorescence spectrum.DB-WPU and DB-WPU are only 8.2-9.2%,which is much lower than migr ation.Because DB is chemically fixed,the ratio of DB+WPU is 34.1%poly urethane chain.The thermal stability of DB-WPU has been significantly improv ed with the increase of the DB content in the polyurethane chain.DB-SWPU shows interesting shelf life stability.Among the three factors of concentration,temperature and time,and the concentration of DB-WPU have the greatest infl uence on K/S value and breaking strength retention(BSR).DB60-SWPU4 can reach 22%,while BSR is about120-130%.The air permeability of DB-WPU4 to dyed fibers is about 400-500 mm s-1,and the total crease recovery angle(warpage+weft)is increased to 155~0.In addition,DB-WPU is also a water solvent,which is particularly suitable for safe,green,and environmentally friendly architectural industrial coatings.