Study On The Properties Of Luminous Materials Recovered From Luminous Polyester Fiber

As a new type of functional fiber newly developed and applied in recent years,rare earth luminous fiber has unique luminous properties,and its wearability has reached the industry standard of textile and apparel.It has received more and more attention in the textile industry and is widely used in apparel and home textiles.With the continuous expansion of the application field of luminous fibers,the demand for luminous fiber textiles will continue to increase.The increase in output has caused a large number of waste luminous fibers in various industries,including scraps and unused defective products in the production process,as well as scrap products used in daily life,which contain a lot of high-performance luminous materials.The recycling of waste luminous fibers is not only a secondary use of raw materials,but also an inevitable requirement for the sustainable development of the environment and society.However,there are few reports on the recycling of luminescent materials in luminous fibers.Therefore,the research on the recycling and reuse of luminous fiber waste has certain scientific significance and research value.The specific research content is as follows:First,using waste rare earth strontium aluminate(Sr Al₂O₄:Eu²⁺,Dy³⁺)luminous polyester fiber as raw material,the alcoholysis recovery plan of luminous polyester fiber was initially explored.Scanning electron microscope,Fourier transform infrared spectrometer,Thermal gravimetric analyzer and Nuclear magnetic resonance spectrometer were used to characterize and analyze the alcoholysis products and recovered luminescent materials.The results showed that the melting point of the alcoholysis products was 112?,it can be seen that the alcoholysis product is mainly diethylene glycol terephthalate(BHET),indicating that the polyester in the waste luminous polyester fiber is completely alcoholyzed,and the product BHET with higher purity can be obtained,and the Sr Al₂O₄:Eu²⁺,Dy³⁺in the luminous fiber does not have an irreversible effect on the alcoholysis process;the recovered luminescent material and rare earth strontium aluminate powder were compared and analyzed by infrared spectroscopy.The result shows that the spectra basically overlapped,indicating that the alcoholysis process did not change the microstructure of the luminescent material.Based on the principle of thermal degradation and recovery,a reaction kinetic model of luminous polyester fiber under glycolysis was established.The results show that the alcoholysis of luminous polyester fiber belongs to the first-order kinetic reaction,and the kinetic equation is k=5.435×10⁸e^-75.821/RT.In order to optimize the parameters of alcoholysis and recovery,this paper uses the alcoholysis rate,the yield of BHET,and the purity of the recovered luminescent material as three indicators to study the effect of addition of catalyst,reaction temperature,and reaction time on the alcoholysis and recovery reaction.The appropriate alcoholysis process conditions was obtained:the addition of catalyst was 0.5%,the reaction temperature was 196?,and the reaction time was 3h,under which the alcoholysis of the luminous fibers can be relatively complete.The solution rate was 99.2%,the BHET yield was77.32%,and the purity of the recovered luminous materials reached 92%.In order to further study the applicability of the recycling scheme to a variety of luminous polyester fibers,under the same conditions,three luminous polyester fibers with different luminous powder content were alcoholyzed,and polyester fibers were selected as the reference material.From the perspective of structure and molecular weight,the influence of raw materials on the alcoholysis reaction and recovery efficiency was analyzed.The recovered samples 1#,2#,3#obtained by drying and grinding and Sr Al₂O₄:Eu²⁺,Dy³⁺raw materials were subjected to microscopic morphology(scanning electron microscope),fluorescence spectrum(excitation emission spectrum),phase analysis(X-ray diffraction),Afterglow performance and other tests are compared,and the performance difference between the recovered sample and the original powder is analyzed.The results show that:the surface of the recovered luminescent material is coated with a layer of oligomers.When the alcoholysis rate is higher,the fewer impurities on the surface and the better its luminescent performance.The XRD spectrum of the sample did not change obviously,indicating that alcoholysis process did not change the crystal structure of rare earth strontium aluminate,and its luminescence mechanism did not change.The luminescence intensity and afterglow brightness were reduced to a certain extent,but the initial afterglow brightness could reach 4.23cd/m²,and the afterglow can still reach 61.43mcd/m² after20 minutes,which shows the value of recycling and provides a test basis for the recycling and utilization of luminescent materials.