Light Absorption And Emission Of Colorful Waterborne Polyurethane Based On Diol Dyes

Waterborne polyurethane dyes use small molecule dyes as raw materials to synthesize colorful waterborne polyurethane.It can efficiently solve the problem of bad compatibility,weak binding force and poor safety,deriving from traditional system of blending dyes and other materials.However,the types of waterborne polyurethane dyes are not abundant to meet all the requirement due to limiting of synthetic methods and dyes reactive groups.On the other hand,the study of waterborne polyurethane dyes focuses on the application in color,while the systemic research of light absorption,luminescence mechanism of fluorescence and phosphorescence,special luminescent properties and color mechanism are absent.Herein,we synthesize small molecule diol or diamine dye by chemically modifying commen dyes with reactive groups and used them as chain extender to prepare a series of colorful waterborne polyurethane with diferent optical properties.This method can efficiently transfer traditional dyes to polymeric and waterborne matetials.Phosphorescent waterborne polyurethane,white fluorescent waterborne polyurethane and black waterbore polyurethane are prepared and their optical properties are studied.The waterborne polyurethane can apply on surface of matrix to achieve prominent coatings.There are five parts in this research:1.Design and synthesis of small molecule dyes diols.A series of small molecular dyes diols or diamines with different absorbance aand luminescent properties were prepared by reasonable chemical modification including fluorescent small molecules KZ,NBP,GAF and RDB,small dyes SDB,EBT-BDiol and AB10B-BDiol,phosphorescent small molecule F1.NMR,IR or MS were tested to prove the successful synthesis of small molecules,which can be used to prepare waterborne polyurethane with different light absorption properties or light-emitting properties.2.Design and synthesis fluorescent waterborne polyurethane.The fluorescence properties of fluorescent waterborne polyurethane were studied with four kinds of fluorescent small molecules.The fluorescence properties were reserved and the fluorescence intensity was greatly enhanced.At the same time,these fluorescent molecules can be combined to prepare diferent fluorescent waterborne polyurethane.The fluorescence emission were obtained by the fluorescence emission superposition of the small molecules,but not the linear superposition.The fluorescence intensity of the long wavelength fluorescent group was significantly enhanced.3.The design and synthesis of white fluorescent waterborne polyurethane.Novel white fluorescent waterborne polyurethane is prepared by blending red,green and blue fluorescent dyes and using them as chain extender.This methods provide a meaningful white fluorescence from new single polymer system by combining three primary colors.Aggregation-caused quenching is weakened and fluorescent intensity is enhanced because polyurethane matrix can efficiently limit vibration and aggregation of fluorescent chromophore.This method can easily achieve white-luminescence dyes to polymeric and waterborne matetials.It can be directly applied in luminescent films and luminescent coatings4.The design and synthesis of Black Waterborne Polyurethane Dyes.A series of black waterborne polyurethane dyes with different ratios of black chromophore from a common black dye,Sudan Black B(SDB),are prepared by step-growth polymerization.The polyurethane latex can possess low particle size and remarkable stability.FT-IR,GPC analyse,UV-vis spectra,DLS,DSC,and TGA analysis indicate that SDB is successfully linked covalently into polyurethane chains to prepare polymeric dyes.When the dyes’ movability is limited seriously for the polyurethane chains,the products exhibit great stability,low migrated ratio in emulsion or film,prominent thermal property from polyurethane substrate and strongly black shining from SDB.Afterwards,different polymeric diols are used to prepare different WPUs with constant SDB to expand applicable range for various demand.The black waterborne polyurethane can be directly used in metal coatings and paints by spraying without complex dying process after simply mixing with coating additives and other waterborne resin,which exhibit excellent coating performance.5.The design and synthesis of phosphorescent waterborne polyurethane.Room-temperature phosphorescence(RTP)from purely organic systems is of practical importance in biological imaging,oxygen sensing and displaying technologies.The key step to obtaining RTP from organic molecules is efficient intersystem crossing(ISC),which is usually low compared to inorganic materials.Here we show that protonation of a dye molecule,a thioflavin derivative,in strongly polar polyurethane can be used to effectively harness RTP.Prior to protonation,the predominant transition is π-π*for the polymer,which has nearly undetectable RTP due to the large singlet-triplet energy splitting(0.87 eV);when Br(?)nsted acids are gradually added to the system,increasingly strong RTP is observed due to the presence of a new intramolecular charge-transfer state(ICT).The ICT state serves to bridge the 1(π-π*)and 3(π-π*)states and leads to a narrowed singlet-triplet energy gap(0.46 eV).The smaller gap results in more efficient ISC and thus strong RTP under deoxygenated conditions.The thioflavin-polyurethane system can be tuned via proton concentration and counterions and opens new doors for RTP-based polymeric sensors and stimuli-responsive materials.Herein,a series of waterborne polyurethane dyes were designed and synthesized,including phosphorescent polyurethane,black waterborne polyurethane and fluorescent waterborne polyurethane.The absorption and luminescent properties of these waterborne polyurethane dyes and their application prospects were studied.This research provides new method for the application of waterborne polyurethane and basic support for the development of optically functionalized waterborne polyurethane,which lay a foundation for the further study of the optical properties of waterborne polyurethane dyes and the optically functional development of waterborne polyurethane.