Preparation And Properties Of Bonded Rare Earth Polymer Luminescent Materials

Rare earth europium and terbium fluorescent polymers not only have the excellent light-emitting properties of small-molecule fluorescent complexes,but also have the flexibility of polymer materials,moldability,and good compatibility and stability with other polymers.Hence,rare earth europium and terbium fluorescent polymers have received widespread attention.In this paper,europium and terbium ions were used as the luminescence centers,and appropriate ligands were selected to synthesize functional monomers containing hydroxyl groups.Through the addition reaction of functional monomer and diisocyanate,it was introduced into the polyurethane polymer chain to form the bonded rare earth polymer.Then,the bonded rare earth polymer was used as a fluorescent agent to be doped into the waterborne polyurethane to obtain a bonded rare earth polymer fluorescent agent/waterborne polyurethane composite system.The primary contents and results are summarized as follows:1?The hydroxyl-containing europium functional monomers were prepared by using the rare earth europium ion as the luminescence center and the ligands of thenoyltrifluoroacetone,1,10-anhydrous phenanthroline,and dimethylolpropionic acid.The elemental analysis shows that the composition of Eu(TTA)₂DMPAphen is basically consistent with the chemical formula.The stretching vibration absorption peak of the infrared hydroxyl group at 3381 cm^-1proves the fact that DMPA participated in the coordination and formed the hydroxyl-containing complex.The complex has good thermal stability,and its initial decomposition temperature is 206.4?,when the weight loss is 4.7%,the temperature is 206.4-303.7?.The fluorescence analysis showed that the excitation peak wavelength of the complex was at 395 nm,and the strongest emission peak was at 614 nm,which shows Eu³⁺red fluorescence characteristics.2?The hydroxyl-containing terbium functional monomers were prepared by using the rare earth terbium ion as the luminescence center and the ligands of benzoic acid,1,10-anhydrous phenanthroline,and dimethylolpropionic acid.The elemental analysis shows that its composition is basically consistent with the chemical formula Tb(BA)₂DMPAphen,and its hydroxyl absorption peak at 3381 cm^-1proves that DMPA participates in the coordination and forms a hydroxyl-containing complex.This complex has good thermal stability.The initial decomposition temperature is 139?.When the weight loss is5%,the decomposition temperature is 291.10?.The fluorescence analysis shows that the complex has an excitation wavelength of 255 nm and an emission wavelength of 550 nm,which shows the characteristic green fluorescence of terbium ion.3?Through the addition reaction with diisocyanate,Eu(TTA)₂DMPAphen and Tb(BA)₂DMPAphen functional monomers were introduced into the polyurethane molecular chain.A series of bonded rare earth europium and terbium polymer fluorescent agents Eu(TTA)₂DMPAphen-WPUs,Tb(BA)₂DMPAphen-WPUs were prepared.The analysis of TG,DSC,XRD,and fluorescence spectra show that Eu(TTA)₂DMPAphen-WPUs and Tb(BA)₂DMPAphen-WPUs fluorescent agents have good thermal stability,and their initial decomposition temperatures are about 230?and 225?,respectively.The chemical transition temperatures are around-32.1°C and-31.8°C,respectively.Eu(TTA)₂DMPAphen-WPUs and Tb(BA)₂DMPAphen-WPUs have a diffraction peak at the diffraction angle 2?of 19.89°and 19.96°,respectively,showing an amorphous state.In the range of 0%-1%of the mass fraction of the complex,the emission intensity of the luminescent materials increases with the increase of rare earth ions,and there is no fluorescence quenching.4?Eu(TTA)₂DMPAphen-WPUs,Tb(BA)₂DMPAphen-WPUs were doped into waterborne polyurethane to prepare composite system of Eu(TTA)₂DMPAphen-WPUs/WPUs,Tb(BA)₂DMPAphen-WPUs/WPUs.At the same time,Eu(TTA)₂DMPAphen was directly doped into waterborne polyurethane to prepare Eu(TTA)₂DMPAphen/WPUs.The TG,DSC,rheological behavior,and fluorescence spectrum analysis of the sample show that their thermal stability is not much different,the initial decomposition temperature is 124?,the glass transition temperature is around-33.3?,and the rheological behavior is typical.The fluorescence intensity of Eu(TTA)₂DMPAphen-WPUs/WPUs was significantly lower than that of Eu(TTA)₂DMPAphen-WPUs/WPUs,which indicated that the high energy vibration of the hydroxyl group reduced the luminescence intensity of Eu(TTA)₂DMPAphen-WPUs/WPUs,and further supported the formation of bonding polymer.