Optical Absorption Properties And Fluorescence Enhancment Effects Of Waterborne Polyurethane-based Polymeric Dyes

Polymeric dyes have received attention recently,due to their unique physical and chemical properties,and potential applications in a wide variety of fields.However,most of them are polymeric dyes that are only soluble in organic solvents,and have caused severe pollution problems.Absorption characteristics of polymeric dyes determine the depth and undertint of color and energy conversion efficiency.The fluorescence properties of polymeric dyes determine bright and beautiful degree of color.The present research on fluorescence characteristics and optical absorption properties of polymeric dyes is not perfect,which restricts development of polymeric dyes.Polyurethane dyes are unique luminescent material with the important application value theory and application,due to their unique physical and chemical properties,and potential applications in environmental protection,biopharmaceuticals,water treatment and so on.The development of water-borne polymeric dyes is the demanding trend in the future.Waterborne polyurethane possesses optical absorption characteristics,fluorescence enhancement properties and environmental advantages.Therefore the research of waterborne polyurethane-based polymeric dyes has aroused much interest at present.Due to the problems of small molecular dyes in optical absorption,fluorescence emission,utilization rate,migration resistance,heat resistance,environmental protection and other properties,the polymeric dyes can effectively solve the above a series of problems.This dissertation mainly focuses on synthesis and optical properties of waterborne polyurethane-based polymeric dyes.A series of waterborne polyurethane-based dyes were designed and synthesized such as four-primary colors,purple,black and brightener.The properties and structures of the polymeric dyes were investigated.Moreover,Absorption and emission spectra were researched.The main findings are can be further categorized into five main parts as follows:1.A red waterborne polyurethane-based dye was designed.A polymeric dye,aqueous disperse red 5B-based polyurethane dispersion(WPU-DV17),was synthesized depending on a modified acetone process.Structure and properties of WPU-DV17 are characterized.The fluorescence intensity of WPU-DV17 was prominently enhanced comparing with that of DV17.Due to the fluorescence quantum yield increased in WPU-DV17,the intensity of the emitted light outnumbers the intensity of reflected light.The dyeing effects of polymeric dye are more bright and beautiful.The fluorescence intensity was decreased along with increasing temperature between 20 ? and 40 ? and was increased along with increasing temperature between 50 ? and 80 ?,which was an abnormal phenomenon against the general fluorescent materials.WPU-DV17 formed emulsion with electrical double surface layers due to the ionization of acidic groups.The DV17 segments of WPU-DV17 were inside electrical double layer,thus the mobility of DV17 was decreased and DV17 was shielded from possible quenchers.The fluorescence is very stable,and not sensitive to quenchers.2.A yellow waterborne polyurethane-based dye was designed.A waterborne polyurethane-based fluorescent dye WPU-ACN was synthesized by attaching ACN into polyurethane chains depending on the prepolymer-ionomer process.Structure and properties of WPU-ACN are characterized.The fluorescence intensity of WPU-ACN was dramatically enhanced comparing with that of ACN,which could be ascribed mainly to two factors of the stereohindrance effect on exciplex formation and the augmented light absorption area for the emulsion particle.Due to the fluorescence quantum yield increased in WPU-ACN,the intensity of the emitted light outnumbers the intensity of reflected light.The dyeing effects of polymeric dye are more bright and beautiful.WPU-ACN presents a significant hypsochromic shift of the emission maximum about 14 nm for ACN.It was found that the fluorescence intensity of WPU-ACN was increased with increasing temperature,and the fluorescence spectra of WPU-ACN showed positive solvatochromic effect.WPU-ACN formed emulsion with electrical double surface layers due to the ionization of acidic groups.The ACN segments of WPU-ACN were inside electrical double layer,thus the mobility of ACN was decreased and ACN was shielded from possible quenchers.The fluorescence of WPU-ACN emulsion was very stable not only for long-term storage but also for fluorescence quenchers.3.A blue waterborne polyurethane-based dye was designed.A polymeric dye,waterborne polyurethane-based solve blue 78(WPU-SB78)was synthesized by attachment of SB78 to polyurethane chains depending on a modified acetone process.Structure and properties of WPU-SB78 is characterized.WPU-SB78 engendered new peaks at about 520 nm and 760 nm with contrast to SB78 in UV-Vis spectra.The 760 nm peak showed hypsochromic shift with the decrease of molecular weight of polymer.However,the new absorption maxima of 520 nm did not change with enlarged average particle sizes.WPU-SB78 demonstrated both hypsochromic and bathochromic effects when varying with temperature.The fluorescence intensity of the polymer was much higher than that of SB78 in same concentration,which could be ascribed mainly to two factors of the stereohindrance effect on exciplex formation and the augmented light absorption area for the emulsion particle.Due to the fluorescence quantum yield increased in WPU-SB78,the intensity of the emitted light outnumbers the intensity of reflected light.The dyeing effects of polymeric dye are more bright and beautiful.It is found that the fluorescence intensity of the polymer would enhance along with increasing temperature between 20 ? and 40 ?,and decline along with increasing temperature between 40 ? and 90 ?,which was an abnormal phenomenon against the general fluorescent materials.WPU-SB78 formed emulsion with electrical double surface layers due to the ionization of acidic groups.The SB78 segments of WPU-SB78 were inside electrical double layer,thus the mobility of SB78 was decreased and SB78 was shielded from possible quenchers.The fluorescence polymer was not sensitive to quenchers.4.A novel anionic waterborne polyurethane-based fluorescent dye WPU-DV26 was synthesized by incorporating the molecular structure of disperse violet 26(DV26)into the polyurethane chain according to the prepolymer-ionomer process.Structure and properties of WPU-DV26 are characterized.Comparing to the UV-Vis spectrum of DV26,WPU-DV26 showed a hypsochromic shift.The fluorescence intensity of WPU-DV26 was much higher than that of DV26.WPU-DV26 presents a significant hypsochromic shift of the emission maximum about 10 nm for DV26.The fluorescence intensity of WPU-DV26 fluorescent emulsion was enhanced greatly comparing with that of DV26,which could be ascribed mainly to two factors of the stereohindrance effect on exciplex formation and the augmented light absorption area for the emulsion particle.Due to the fluorescence quantum yield increased in WPU-DV26,the intensity of the emitted light outnumbers the intensity of reflected light.The dyeing effects of polymeric dye are more bright and beautiful.WPU-DV26 formed emulsion with electrical double surface layers due to the ionization of acidic groups.The DV26 segments of WPU-DV26 were inside electrical double layer,thus the mobility of DV26 was decreased and DV26 was shielded from possible quenchers.The fluorescence of WPU-DV26 emulsion was very stable not only for the long term storage but also for the fluorescence quenchers.5.A black waterborne polyurethane-based dye was designed.A waterborne polyurethane dye EBT-PU and a reference BDO-PU were synthesized by self-emulsification method.Although the soft and hard segments in chains of EBT-PU and BDO-PU are incompatible,the conjugate structure of EBT has a big effect on the incompatibility comparing to the aliphatic chain of BDO.The experimental result shows that EBT-PU is an amorphous polymer,and the conjugate structure of EBT can introduce a distinct improve for the thermal stability of EBT-PU.EBT-PU was found that the maximum absorption of 528 nm in UV-Visible spectrum appeared a bathochromic shift of 44 nm for EBT because of the disappearance of auxochrome-OH and the change of conjugate system for EBT during the reaction between EBT and-NCO group.Based on Lambert-Beer Law,weight percentage of 12.8%for EBT segments in EBT-PU can be determined by comparison of extinction coefficient of EBT-PU with that of EBT.Waterborne stilbene-based polyurethane fluorescent brightener dispersion(WPU-VBL)was synthesized by incorporating chemically VBL into the waterborne polyurethane chain.Structure and properties of WPU-VBL are characterized.WPU-VBL presents a hysoochromic shift of the absorption maximum about 16 nm for VBL.WPU-VBL presents a hysoochromic shift of the absorption maximum about 16 nm for VBL.The fluorescence intensity of the polymer was prominently enhanced comparing with VBL because of the changes of micro-circumstance of VBL.Due to the fluorescence quantum yield increased in VBL,the intensity of the emitted light outnumbers the intensity of reflected light.The dyeing effects of polymeric dye are more bright and beautiful.WPU-SB78 formed emulsion with electrical double surface layers due to the ionization of acidic groups.The VBL segments of WPU-VBL were inside electrical double layer,thus the mobility of VBL was decreased and VBL was shielded from possible quenchers.Furthermore,the fluorescence of WPU-VBL was not sensitive to hydroquinone quenchers.A series of waterborne polyurethane-based dyes were designed and synthesized Compared with that of the small molecular dyes,the color of polymeric dyes has some changes,and the dyeing effects of polymeric dye are more bright and beautiful.The optical properties and structures of the polymeric dyes were investigated.The waterborne polyurethane-based dyes have fluorescence enhancement,fluorescence response to temperature,fluorescence stability to quenching agents and so on.Provide support for the development and application of aqueous polyurethane dyes.Develop new ideas for the preparation of fluorescent polymers with special purpose.Eastablish the foundation for study the optical properties of polymeric dye further.