Preparation method and application of high-quantum-yield organic long-afterglow polyurethane elastic fiber

Abstract

The application provides a preparation method and application of high-quantum-yield organic long-afterglow polyurethane elastic fiber, and the preparation method comprises the following steps: (1) reacting an oligomer polyol and excess diisocyanate to form an NCO-terminated prepolymer solution, and then adding ethylenediamine dropwise into the prepolymer solution to perform chain extension reaction, so as to obtain a polyurethane spinning solution; (2) adding a fluorescent dye into the polyurethane spinning solution prepared in the step (1) and stirring uniformly at room temperature, so as to form a polyurethane-fluorescent dye spinning stock solution; and (3) performing wet spinning on the polyurethane-fluorescent dye spinning stock solution, so as to obtain the high-quantum-yield organic long-afterglow polyurethane elastic fiber. The application solves the problems of poor flexibility, low quantum yield, short service life, uneven light emission and unstable light emission of the existing long-afterglow light-emitting fiber, and provides a simple and effective preparation method for the preparation of high-quantum-yield organic long-afterglow elastic fiber and higher-end, more comprehensive and more extensive application scenarios.

Description

Technical Field

[0001] This invention relates to the field of functional fiber materials technology, and in particular to a method for preparing and applying a high quantum yield organic long afterglow polyurethane elastic fiber. Background Technology

[0002] With the advancement of technology, wearable clothing has become an emerging fashion trend, attracting increasing attention. Luminescent fiber materials, as an important element in wearable clothing, not only enhance the visual appeal of the garments but also improve their practicality and comfort. The most typical luminescent fibers mainly include fluorescent luminescent fibers and long-afterglow luminescent fibers.

[0003] Currently, fluorescent luminescent fibers are the dominant type on the market. Fluorescent fibers offer advantages such as high quantum yield, strong photostability, and tunable color; however, their need for continuous stimulation from an external light source limits their further application in daily life. Long-afterglow luminescent fibers are fibers incorporating long-afterglow materials, allowing them to continue emitting light even after the excitation source is removed. Existing long-afterglow luminescent fibers are relatively rare, with most being based on inorganic material doping. While inorganic material-doped long-afterglow fibers offer advantages such as long lifespan and high brightness, inorganic afterglow materials suffer from high energy consumption, complex processes, high toxicity, and high cost during synthesis. Furthermore, their luminescence color is difficult to control, and they exhibit poor flexibility during fiber synthesis. Organic long-afterglow materials offer advantages such as low toxicity, low cost, flexible molecular design, and ease of functionalization. Therefore, the research and application of organic long-afterglow luminescent fibers have greater appeal and potential. Summary of the Invention

[0004] To address the aforementioned problems in existing technologies, this invention provides a method for preparing and applying high-quantum-yield organic long-afterglow polyurethane elastic fibers. This invention involves doping polyurethane spinning solutions with fluorescein-based or rhodamine-based fluorescent dyes and utilizing the long-afterglow luminescence properties of tetraacetylethylenediamine (TEEDA) as a phosphorescent guest material. An aqueous solution of TEDA is used as a coagulation bath, and during wet spinning, TEDA is displaced into the polyurethane fibers containing the fluorescent dye to obtain high-quantum-yield organic long-afterglow polyurethane elastic fibers. This solves the problems of poor flexibility, low quantum yield, short lifetime, uneven luminescence, and unstable luminescence in existing long-afterglow luminescent fibers, providing a simple and effective preparation method and more advanced, comprehensive, and wider application scenarios for high-quantum-yield organic long-afterglow elastic fibers.

[0005] The technical solution of the present invention is as follows:

[0006] The first objective of this invention is to provide a method for preparing high quantum yield organic long afterglow polyurethane elastic fibers, the method comprising the following steps:

[0007] (1) React oligomeric polyols with excess diisocyanate to form NCO-terminated prepolymer solutions, then add ethylenediamine (EDA) dropwise to the prepolymer solutions to carry out chain extension reactions, monitor the viscosity of the system, and obtain polyurethane spinning solution;

[0008] (2) Add fluorescent dye to the polyurethane spinning solution obtained in step (1) and stir evenly at room temperature to form polyurethane-fluorescent dye spinning solution.

[0009] (3) The polyurethane-fluorescent dye spinning solution prepared in step (2) is used to prepare the high quantum yield organic long afterglow polyurethane elastic fiber by wet spinning.

[0010] In the wet spinning process, the spinning solution is extruded and then subjected to coagulation bath, drying, and heat setting treatment; the coagulation bath is an aqueous solution containing tetraacetylethylenediamine.

[0011] In one embodiment of the present invention, in step (1), the oligomeric polyol is one or more of polytetrahydrofuran ether diol, polyoxyethylene ether diol, polyoxypropylene ether diol, and polyadipate diol.

[0012] In one embodiment of the present invention, in step (1), the number average molecular weight of the oligomeric polyol is 1000-4000.

[0013] In one embodiment of the present invention, in step (1), the diisocyanate is one or a mixture of 4,4'-diphenylmethane diisocyanate (MDI), dicyclohexylmethane 4,4'-diisocyanate (HMDI).

[0014] In one embodiment of the present invention, in step (1), the molar ratio of the oligomeric polyol to the diisocyanate is 1:1.3-1.8.

[0015] In one embodiment of the present invention, in step (1), the amount of ethylenediamine used is 1-3 times the molar amount of the oligomeric polyol.

[0016] In one embodiment of the present invention, in step (1), the viscosity of the polyurethane spinning solution is 5000-10000 mPa·s, and the solid content is 25-40%.

[0017] In one embodiment of the present invention, in step (2), the fluorescent dye is an organic small molecule fluorescent dye;

[0018] Furthermore, the fluorescent dye is a fluorescein-type or rhodamine-type organic small molecule fluorescent dye;

[0019] Furthermore, one of the fluorescent dyes is rhodamine OH (RhOH), whose structure is shown in Formula 1:

[0020]

[0021] Rhodamine OH and phosphors have the highest energy transfer efficiency.

[0022] In one embodiment of the present invention, in step (2), the amount of the fluorescent dye used is 0.001-0.1 wt% of the polyurethane spinning solution.

[0023] In one embodiment of the present invention, in step (3), tetraacetylethylenediamine is an atypical long afterglow luminescent material, and its content in the coagulation bath is 1-10 wt%.

[0024] In one embodiment of the present invention, in step (3), the temperature of the coagulation bath is 50-80°C.

[0025] In one embodiment of the present invention, in step (3), after extrusion, the draw ratio during the forming process is 1.5-3.5.

[0026] In one embodiment of the present invention, in step (3), the drying temperature is 60-160°C; the heat setting temperature is 100-200°C, and the heat setting draw ratio is 1.2-2.

[0027] In one embodiment of the present invention, the high quantum yield organic long afterglow polyurethane elastic fiber has a phosphorescence quantum yield of 25-90% and a phosphorescence lifetime of more than 1 second.

[0028] The second objective of this invention is to provide an application of the high quantum yield organic long afterglow polyurethane elastic fiber for textile anti-counterfeiting, information encryption, and clothing safety warnings.

[0029] Furthermore, information encryption can be achieved in the form of QR codes or barcodes made of fibers.

[0030] In one embodiment of the present invention, the high quantum yield organic long afterglow polyurethane elastic fiber is used to prepare smart wearable clothing, wearable optoelectronic devices, and flexible displays.

[0031] The beneficial technical effects of this invention are as follows:

[0032] Based on the luminescent properties of the guest phosphorescent molecule tetraacetylethylenediamine, this invention designs rhodamine-based fluorescent dyes to maximize the energy transfer efficiency between the dye and tetraacetylethylenediamine, which serves as the energy donor, thereby maximizing the quantum yield and lifetime of the material.

[0033] This invention uses an aqueous solution of tetraacetylethylenediamine as a coagulation bath and employs wet spinning to replace tetraacetylethylenediamine in polyurethane fibers containing fluorescent dyes to obtain high quantum yield organic long afterglow polyurethane elastic fibers. The preparation method of this invention is simple and efficient, and the obtained polyurethane fibers have advantages such as high elasticity, high quantum yield, long life, uniform luminescence, and strong tensile stability. They have more advanced, comprehensive, and wider applications in fields such as clothing safety warnings, textile anti-counterfeiting, information encryption, smart wearables, wearable optoelectronic devices, and flexible displays. Attached Figure Description

[0034] Figure 1 The 1H NMR spectrum of Rhodamine OH (RhOH) is shown.

[0035] Figure 2 The images show the actual ultraviolet irradiation and long afterglow luminescence of the polyurethane elastic fibers obtained in Examples 1-3.

[0036] Figure 3 The anti-counterfeiting properties of the polyurethane elastic fibers obtained in Example 2 and Comparative Example 3 are shown. Detailed Implementation

[0037] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0038] The synthesis method of rhodamine OH (RhOH) includes the following steps:

[0039] (1) Dissolve 10 g (32 mmol) of 4-diethylaminoketo acid and 3.60 g (32.8 mmol) of resorcinol in 60 ml of trifluoroacetic acid, heat to 90 °C and reflux for 12 h. After the reaction is complete, remove trifluoroacetic acid by rotary evaporation to obtain crude product.

[0040] (2) The crude product obtained in step (1) was added to a mixed solvent containing dichloromethane, ethyl acetate and ethanol, heated under reflux at 55°C for 2 hours, filtered while hot, and the filter cake was dried. This process was repeated twice to obtain 8.85 g of dark red powder, namely Rhodamine OH (RhOH); its 1H NMR spectrum is shown below. Figure 1 As shown.

[0041] 1 HNMR(400MHz DMSO-d6)δ8.12(d,J=7.3Hz,1H),7.81(dt,J=28.6,7.3Hz,2H),7.39(d,J=7.4Hz, 1H), 6.84 (dd, J=40.0, 19.3Hz, 6H), 3.54 (d, J=2.9Hz, 4H), 1.16 (t, J=6.9Hz.6H).

[0042] This invention employs heating and reflux followed by hot filtration to separate and purify the target product, rather than using column chromatography for purification. This method is simple to operate, saves time and effort, and significantly reduces solvent usage, while being highly efficient and clean.

[0043] Example 1

[0044] A method for preparing high quantum yield organic long afterglow polyurethane elastic fiber includes the following steps:

[0045] (1) Polytetrahydrofuran glycol (0.02 mol) with a number average molecular weight of 2000 and 4,4'-diphenylmethane diisocyanate (0.034 mol) were reacted to form an NCO-terminated prepolymer solution. Then, 0.05 mol of ethylenediamine was added dropwise to the prepolymer solution to carry out a chain extension reaction. The viscosity of the system was monitored to be 7000 mPa·s, and a polyurethane spinning solution was obtained.

[0046] (2) Add fluorescent dye (CAS: 2321-07-5) (0.05% of the mass of polyurethane spinning solution) to the polyurethane spinning solution obtained in step (1) and stir evenly at room temperature to form polyurethane-fluorescent dye spinning solution.

[0047] (3) The polyurethane-fluorescent dye spinning solution prepared in step (2) is used to prepare the high quantum yield organic long afterglow polyurethane elastic fiber by wet spinning.

[0048] In the wet spinning process, the spinning solution is extruded and then subjected to coagulation bath, drying, and heat setting treatment. The coagulation bath is a 5% tetraacetylethylenediamine aqueous solution at a temperature of 70°C. After the polyurethane spinning solution is extruded from the spinneret, the draw ratio during the forming process is 2, the fiber drying temperature is 100°C, and the heat setting temperature is 120°C with a draw ratio of 2.

[0049] Example 2

[0050] A method for preparing high quantum yield organic long afterglow polyurethane elastic fiber includes the following steps:

[0051] (1) Polytetrahydrofuran diol (0.01 mol) with a number average molecular weight of 3000 and 4,4'-diphenylmethane diisocyanate (0.016 mol) were reacted to form an NCO-terminated prepolymer solution. Then, 0.02 mol of ethylenediamine was added dropwise to the prepolymer solution to carry out a chain extension reaction. The viscosity of the system was monitored to be 8000 mPa·s, and a polyurethane spinning solution was obtained.

[0052] (2) Add RhOH fluorescent dye (0.01% of the mass of polyurethane spinning solution) to the polyurethane spinning solution obtained in step (1) and stir evenly at room temperature to form polyurethane-fluorescent dye spinning solution.

[0053] (3) The polyurethane-fluorescent dye spinning solution prepared in step (2) is used to prepare the high quantum yield organic long afterglow polyurethane elastic fiber by wet spinning.

[0054] In the wet spinning process, the spinning solution is extruded and then subjected to coagulation bath, drying, and heat setting treatment. The coagulation bath is a 6% tetraacetylethylenediamine aqueous solution at a temperature of 70°C. After the polyurethane spinning solution is extruded from the spinneret, the draw ratio during the forming process is 1.6, the fiber drying temperature is 120°C, and the heat setting temperature is 140°C with a draw ratio of 1.8.

[0055] Example 3

[0056] A method for preparing high quantum yield organic long afterglow polyurethane elastic fiber includes the following steps:

[0057] (1) Polytetrahydrofuran diol (0.01 mol) with a number average molecular weight of 1500 and 4,4'-diphenylmethane diisocyanate (0.018 mol) were reacted to form an NCO-terminated prepolymer solution. Then, 0.01 mol of ethylenediamine was added dropwise to the prepolymer solution to carry out a chain extension reaction. The viscosity of the system was monitored to be 6000 mPa·s, and a polyurethane spinning solution was obtained.

[0058] (2) Add Rhodamine B fluorescent dye (0.02% of the mass of polyurethane spinning solution) to the polyurethane spinning solution obtained in step (1) and stir evenly at room temperature to form polyurethane-fluorescent dye spinning solution.

[0059] (3) The polyurethane-fluorescent dye spinning solution prepared in step (2) is used to prepare the high quantum yield organic long afterglow polyurethane elastic fiber by wet spinning.

[0060] In the wet spinning process, the spinning solution is extruded and then subjected to coagulation bath, drying, and heat setting treatment. The coagulation bath is an 8% tetraacetylethylenediamine aqueous solution at a temperature of 80°C. After the polyurethane spinning solution is extruded from the spinneret, the draw ratio during the forming process is 1.5, the fiber drying temperature is 110°C, and the heat setting temperature is 130°C with a draw ratio of 1.6.

[0061] Compare with Example 1

[0062] A method for preparing organic long-afterglow polyurethane elastic fiber includes the following steps:

[0063] (1) Polytetrahydrofuran diol (0.01 mol) with a number average molecular weight of 1500 and 4,4'-diphenylmethane diisocyanate (0.018 mol) were reacted to form an NCO-terminated prepolymer solution. Then, 0.01 mol of ethylenediamine was added dropwise to the prepolymer solution to carry out a chain extension reaction. The viscosity of the system was monitored to be 6000 mPa·s, and a polyurethane spinning solution was obtained.

[0064] (2) Add tetraacetylethylenediamine (8% of the mass of polyurethane spinning solution) to the polyurethane spinning solution obtained in step (1) and stir evenly at room temperature to form polyurethane-tetraacetylethylenediamine spinning solution.

[0065] (3) The polyurethane-tetraacetylethylenediamine spinning solution prepared in step (2) is used to prepare organic long afterglow polyurethane elastic fiber by wet spinning.

[0066] In the wet spinning process, the spinning solution is extruded and then subjected to coagulation bath, drying, and heat setting treatment. The coagulation bath contains 0.01% RhOH fluorescent dye at a temperature of 80℃. After the polyurethane spinning solution is extruded from the spinneret, the draw ratio during the forming process is 1.5, the fiber drying temperature is 110℃, and the heat setting temperature is 130℃ with a draw ratio of 1.6.

[0067] Compare with Example 2

[0068] A method for preparing organic long-afterglow polyurethane elastic fiber includes the following steps:

[0069] (1) Polytetrahydrofuran diol (0.01 mol) with a number average molecular weight of 1500 and 4,4'-diphenylmethane diisocyanate (0.018 mol) were reacted to form an NCO-terminated prepolymer solution. Then, 0.01 mol of ethylenediamine was added dropwise to the prepolymer solution to carry out a chain extension reaction. The viscosity of the system was monitored to be 6000 mPa·s, and a polyurethane spinning solution was obtained.

[0070] (2) Add tetraacetylethylenediamine and RhOH fluorescent dye to the polyurethane spinning solution obtained in step (1) (the amount of tetraacetylethylenediamine is 8% of the mass of the polyurethane spinning solution, and the amount of RhOH fluorescent dye is 0.01% of the mass of the polyurethane spinning solution), stir evenly at room temperature to form polyurethane-tetraacetylethylenediamine-fluorescent dye spinning solution.

[0071] (3) The polyurethane-tetraacetylethylenediamine-fluorescent dye spinning solution prepared in step (2) is used to prepare organic long afterglow polyurethane elastic fiber by wet spinning.

[0072] In the wet spinning process, the spinning solution is extruded and then subjected to coagulation bath, drying, and heat setting. The coagulation bath is pure water at a temperature of 80°C. After the polyurethane spinning solution is extruded from the spinneret, the draw ratio during the forming process is 1.5, the fiber drying temperature is 110°C, and the heat setting temperature is 130°C with a draw ratio of 1.6.

[0073] Compare with Example 3

[0074] A method for preparing organic long-afterglow polyurethane elastic fiber includes the following steps:

[0075] (1) Polytetrahydrofuran diol (0.01 mol) with a number average molecular weight of 3000 and 4,4'-diphenylmethane diisocyanate (0.016 mol) were reacted to form an NCO-terminated prepolymer solution. Then, 0.02 mol of ethylenediamine was added dropwise to the prepolymer solution to carry out a chain extension reaction. The viscosity of the system was monitored to be 8000 mPa·s, and a polyurethane spinning solution was obtained.

[0076] (2) Add RhOH fluorescent dye (0.01% of the mass of polyurethane spinning solution) to the polyurethane spinning solution obtained in step (1) and stir evenly at room temperature to form polyurethane-fluorescent dye spinning solution.

[0077] (3) The polyurethane-fluorescent dye spinning solution prepared in step (2) is used to prepare organic long afterglow polyurethane elastic fiber by wet spinning.

[0078] In the wet spinning process, the spinning solution is extruded and then subjected to coagulation bath, drying, and heat setting treatment. The coagulation bath is a 0.2% tetraacetylethylenediamine aqueous solution at a temperature of 70°C. After the polyurethane spinning solution is extruded from the spinneret, the draw ratio during the forming process is 1.6, the fiber drying temperature is 120°C, and the heat setting temperature is 140°C with a draw ratio of 1.8.

[0079] Test example:

[0080] (1) Luminous properties

[0081] The phosphorescence quantum yield was measured in an FLS 980 fluorescence spectrometer using a polytetrafluoroethylene-lined integrating sphere (F-M101, Edinburgh, diameter: 150 mm, weight: 2 kg) at a delay of 100 ns.

[0082] The phosphorescence lifetime was measured using a xenon lamp in an FLS 980 fluorescence spectrometer, and the lifetime value was obtained by fitting the data in software.

[0083] The quality factor, which is the product of quantum yield and lifetime, reflects the overall performance of long-afterglow luminescent materials.

[0084] Table 1 shows the phosphorescence quantum yield, phosphorescence lifetime, quality factor, and lifetime after stretching and stretching cycles of the polyurethane elastic fibers obtained in Examples 1-3 and Comparative Examples 1-3. When the polyurethane elastic fibers obtained in Examples 1-3 were irradiated with a UV lamp, after the UV lamp was turned off, there was a continuous luminescence time of 7-9 seconds. Figure 2 As shown.

[0085] Table 1

[0086]

[0087] (2) Anti-counterfeiting performance

[0088] The fibers obtained in Example 2 and Comparative Example 3 were used as the right and left wings of a butterfly, respectively, and sewn onto a black T-shirt as an anti-counterfeiting label. When the fibers were irradiated with ultraviolet light, a complete butterfly shape appeared. When the ultraviolet light was turned off, only the fiber obtained in Example 2, i.e., the right wing of the butterfly, continued to emit light, achieving a multi-layered, high-end anti-counterfeiting effect and purpose for the textile. The actual images of the ultraviolet irradiation and afterglow are shown below. Figure 3 As shown.

[0089] This invention provides a method for preparing high quantum yield organic long-afterglow polyurethane elastic fibers and their applications in clothing safety warnings, textile anti-counterfeiting, and flexible displays. Fluorescein-based or rhodamine-based fluorescent dyes are incorporated into the polyurethane spinning solution. Utilizing the long-afterglow, long-lasting luminescence characteristic of tetraacetylethylenediamine (TEED), a phosphorescent guest material, and using an aqueous solution of TEED as a coagulation bath, the TEED is replaced in the polyurethane fiber containing the fluorescent dye during wet spinning to obtain high quantum yield organic long-afterglow polyurethane elastic fibers. This method solves the problems of poor flexibility, low quantum yield, short lifespan, uneven luminescence, and unstable luminescence in existing long-afterglow luminescent fibers, providing a simple and effective preparation method and enabling more advanced, comprehensive, and wider applications for high quantum yield organic long-afterglow elastic fibers. If TEED is directly incorporated into the polyurethane spinning solution for spinning, it is difficult to obtain high-brightness long-afterglow luminescent fibers due to solubility issues, or even difficult to form fibers, and the resulting fibers have poor luminescence stability.

[0090] The embodiments provided above are not intended to limit the scope of the invention, nor are the described steps intended to limit the order of execution. Any obvious modifications made to the invention by those skilled in the art based on existing common knowledge also fall within the scope of protection defined by the claims.

Claims

1. A method for preparing high quantum yield organic long afterglow polyurethane elastomeric fibers, characterized by, The preparation method comprises the following steps: (1) reacting an oligomer polyol and an excess of diisocyanate to form an NCO-terminated prepolymer solution, then adding ethylenediamine dropwise to the prepolymer solution to perform chain extension, and monitoring the viscosity of the system to obtain a polyurethane spinning solution; (2) adding a fluorescent dye to the polyurethane spinning solution obtained in step (1) and stirring uniformly at room temperature to form a polyurethane-fluorescent dye spinning dope; the fluorescent dye is a fluorescein or rhodamine organic small-molecule fluorescent dye; (3) preparing the high-quantum-yield organic long-afterglow polyurethane elastic fiber by wet spinning of the polyurethane-fluorescent dye spinning dope prepared in step (2); the content of tetraacetyl ethylenediamine in the coagulation bath is 1-10 wt%; In the wet spinning process, the spinning dope is extruded and then subjected to a coagulation bath, drying and heat setting treatment; the coagulation bath is an aqueous solution containing tetraacetyl ethylenediamine.

2. The production method according to claim 1, characterized by, In step (1), the oligomer polyol is one or more of polytetrahydrofuran ether glycol, polyoxyethylene ether glycol, polyoxypropylene ether glycol and polyadipate glycol; the number average molecular weight of the oligomer polyol is 1000-4000.

3. The preparation method according to claim 1, characterized in that, In step (1), the diisocyanate is one or a mixture of two of 4,4'-diphenylmethane diisocyanate and dicyclohexylmethane 4,4'-diisocyanate.

4. The method of claim 1, wherein, In step (1), the molar ratio of the oligomer polyol to diisocyanate is 1:1.3-1.8; the amount of ethylenediamine is 1-3 times the molar amount of the oligomer polyol.

5. The production method according to claim 1, characterized by, In step (1), the viscosity of the polyurethane spinning solution is 5000-10000 mPa·s, and the solid content is 25%-40%.

6. The method of claim 1, wherein, In step (2), the fluorescent dye is an organic small-molecule fluorescent dye; the amount of the fluorescent dye is 0.001-0.1 wt% of the polyurethane spinning solution.

7. The preparation method according to claim 1, characterized in that, In step (3), the temperature of the coagulation bath is 50-80℃.

8. Use of the high quantum yield organic long afterglow polyurethane elastomeric fiber according to claim 1, characterized in that, For textile anti-counterfeiting, information encryption or clothing safety warning.

9. Use of the high quantum yield organic long afterglow polyurethane elastomeric fiber according to claim 1, characterized in that, For preparing smart wearable clothes, wearable optoelectronic devices or flexible displays.

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