High-strength yellow fluorescent polyurethane elastomer and preparation method thereof

Abstract

The invention discloses a high-strength yellow fluorescent polyurethane elastomer and a preparation method thereof. According to the method, 3, 3 '-diaminobenzidine and 3, 3', 4, 4 '-benzophenone tetracarboxylic dianhydride are used as raw materials to synthesize an oligomer containing a polyamino aromatic ring and a hybrid structure, the oligomer reacts with an isocyanate compound to form an-NCO functionalized oligomer system, and the-NCO functionalized oligomer system further reacts with a polyol compound to form the high-strength yellow fluorescent polyurethane elastomer. Compared with the existing similar fluorescent polyurethane elastomer, the polyurethane elastomer prepared by the invention not only has high glass transition temperature and tensile strength, but also has yellow fluorescence property and high-temperature fluorescence stability, and is beneficial to application in the fields of aerospace and the like.

Description

Technical Field

[0001] The present invention belongs to the field of polyurethane elastomers, and particularly relates to a high-strength yellow fluorescent polyurethane elastomer and a preparation method thereof. Background Art

[0002] Fluorescent substances have a wide range of applications in fields such as developers, luminescent materials, probes, bioimaging, and sensors. Small molecule fluorescent substances have problems such as unstable fluorescent properties and poor safety, which will seriously inhibit their applications; blending fluorescent molecular substances with polymers will cause uneven dispersion of fluorescent substances and deterioration of fluorescent properties and polymer properties; based on chemical methods to introduce fluorescent substances into polymers, although it can significantly improve the dispersion of fluorescent substances in polymers and is beneficial to maintaining the mechanical properties of polymers, due to the chemical reaction between the fluorescent substance and the polymer components, the fluorescent properties will be modified due to the change of the electron transition mode in the constructed system. Therefore, it is of great significance to prepare polymer materials with stable fluorescent properties. In the currently constructed fluorescent polymer system, the polyurethane elastomer system has become one of the main polymers for constructing the fluorescent polymer system due to its excellent mechanical properties, rich hydrogen bonds, and rapid mechanical response ability. At present, in the fluorescent polyurethane elastomer system, the polyurethane polymer system mostly uses blue fluorescence as the mainstream, and its fluorescent properties are easily affected by factors such as force and temperature, showing low environmental fluorescence resistance, which further limits the application of fluorescent polyurethane polymers in harsh environments. Although there are reports in the literature on other fluorescent properties, especially fluorescent polyurethane systems in the long-wave direction (or red-orange-yellow), most of them are achieved by adding fluorescent pigments or fluorescent quantum dots. It is rare to prepare a long-wave direction (or red-orange-yellow) fluorescent polyurethane elastomer system based on polymerization copolymerization. It can be seen that the research and development of high-heat-resistant long-wave direction fluorescent polyurethane elastomers with wide applicability has positive significance for promoting their applications in fields such as bioimaging, sensors, anti-counterfeiting materials, and aerospace. Summary of the Invention

[0003] Based on the problems of poor heat resistance and lack of long-wave direction fluorescent polyurethane elastomer systems in existing fluorescent polyurethane elastomers, the present invention introduces an aryl ring and hybrid structure oligomer system containing terminal amino groups into the polyurethane system to prepare a high-strength yellow fluorescent polyurethane elastomer. The prepared fluorescent polyurethane system not only has excellent mechanical properties, but also has high heat resistance and high-temperature yellow fluorescence stability.

[0004] To achieve the above object, the technical solution adopted by the present invention is as follows.

[0005] A preparation method of a high-strength yellow fluorescent polyurethane elastomer, comprising the following steps: (1) Using 3,3'-diaminobenzidine and 3,3',4,4'-benzophenone tetracarboxylic dianhydride as raw materials, reacting to prepare an oligomer; (2) Using the oligomer and the diisocyanate compound as raw materials, reacting to prepare an isocyanate-functionalized oligomer; (3) Using the isocyanate-functionalized oligomer and the polyol as raw materials, in the presence of a catalyst, reacting to prepare a prepolymer; then curing the prepolymer to obtain a high-strength yellow fluorescent polyurethane elastomer.

[0006] A preparation method of a prepolymer for a high-strength yellow fluorescent polyurethane elastomer, comprising the following steps, (1) Using 3,3'-diaminobenzidine and 3,3',4,4'-benzophenone tetracarboxylic dianhydride as raw materials, preparing an oligomer; (2) Using the oligomer and the diisocyanate compound as raw materials, preparing an isocyanate-functionalized oligomer; (3) Using the isocyanate-functionalized oligomer and the polyol as raw materials, in the presence of a catalyst, preparing a prepolymer for a high-strength yellow fluorescent polyurethane elastomer.

[0007] In the present invention, the molar ratio of 3,3'-diaminobenzidine, 3,3',4,4'-benzophenone tetracarboxylic dianhydride, diisocyanate compound, polyol, and catalyst is 2:(0.8 - 1.2):(50 - 65):(5 - 10):(0.01 - 0.06).

[0008] In the present invention, the diisocyanate compound includes one or more of isophorone diisocyanate, toluene diisocyanate, diphenylmethane diisocyanate, dicyclohexylmethane diisocyanate, hexamethylene diisocyanate, and lysine diisocyanate; the polyol includes one or more of polyether polyol and polyester polyol; the catalyst includes one or more of organotin and organolead.

[0009] In the present invention, in step (1), the reaction temperature is 80 - 100 °C and the time is 0.5 - 2 hours; in step (2), the reaction temperature is 90 - 110 °C and the time is 0.5 - 2 hours; in step (3), the reaction temperature is 70 - 90 °C and the time is 0.5 - 2 hours, and the reaction is carried out under a protective atmosphere.

[0010] In the present invention, the curing is carried out at 40 - 60 °C for 10 - 15 hours, and then at 80 - 100 °C for 4 - 6 h.

[0011] The present invention discloses a high-strength yellow fluorescent polyurethane elastomer or a prepolymer for a high-strength yellow fluorescent polyurethane elastomer prepared according to the above preparation method. Preferably, the glass transition temperature of the high-strength yellow fluorescent polyurethane elastomer is greater than 190 °C or even greater than 220 °C, and the tensile strength is not less than 20 MPa.

[0012] The present invention discloses the application of the above-mentioned high-strength yellow fluorescent polyurethane elastomer or the prepolymer for high-strength yellow fluorescent polyurethane elastomer in being used as or preparing high-strength yellow fluorescent materials.

[0013] The present invention discloses a high-strength yellow fluorescent material, and its preparation raw materials include the above-mentioned high-strength yellow fluorescent polyurethane elastomer or the prepolymer for high-strength yellow fluorescent polyurethane elastomer.

[0014] In the present invention, 3,3'-diaminobenzidine and 3,3',4,4'-benzophenone tetracarboxylic dianhydride are respectively dissolved in solvent A, and reacted at 90 °C for 0.5 - 2 h, preferably 1.5 - 2 h to obtain an oligomer solution; then solvent B and a diisocyanate compound are added, and reacted at 100 °C for 0.5 - 2 h, preferably 1.5 - 2 h to obtain an -NCO functionalized DTA solution, then solvent C, a polyol compound and a catalyst are added, and reacted at 80 °C for 1.5 - 2 h under nitrogen protection to obtain a prepolymer solution, and the solution is cast into a mold and heat-treated at 50 °C / 12 h + 80 - 100 °C / 4 - 6 h to obtain a polyurethane elastomer film. Among them, the molar ratio of 3,3'-diaminobenzidine, 3,3',4,4'-benzophenone tetracarboxylic dianhydride, diisocyanate compound, polyol compound, catalyst, solvent A, solvent B, and solvent C is 2:(0.8 - 1.2):(50 - 65):(5 - 10):(0.01 - 0.06):(100 - 140):(0 - 130):(130 - 300).

[0015] The polyurethane elastomer prepared by the present invention not only has a high glass transition temperature (~229 °C) and tensile strength, but also has yellow fluorescence performance and high-temperature fluorescence stability.

[0016] Compared with the prior art, the beneficial effects obtained by the present invention are: the fluorescent polyurethane elastomer of the present invention is a yellow fluorescent polyurethane elastomer constructed based on non-fluorescent pigment substances and fluorescent quantum dots. Compared with the fluorescent polyurethane elastomer material system prepared by the existing copolymerization method, it not only has good stability of temperature-resistant fluorescence performance, but also has a longer emission wavelength. Description of the Drawings

[0017] Figure 1 It is the infrared spectrum of 3,3'-diaminobenzidine, 3,3',4,4'-benzophenone tetracarboxylic dianhydride and DTA.

[0018] Figure 2 It is the infrared spectrum and fluorescence (PL) spectrum (excitation wavelength 365 nm) of the samples of Example 1 and Comparative Example 1-1 at different temperatures, where (a) is the infrared spectrum and (b) is the PL spectrum.

[0019] Figure 3Photographs of the samples of Example 1, Comparative Example 1-1, the DMF solution of DTA, DTA powder, Comparative Example 1-2, and Comparative Example 1-3 under daylight illumination at 25 °C and under 365 nm ultraviolet lamp irradiation at 25 °C and 160 °C. Among them, (a), (a'), and (a'') are the photographs of the sample of Example 1; (b), (b'), and (b'') are the photographs of the sample of Comparative Example 1-1; (c) and (c') are the photographs of the DTA solution sample; (d) and (d') are the photographs of the DTA powder sample; (e) and (e') are the photographs of the sample of Comparative Example 1-2; (f) and (f') are the photographs of the sample of Comparative Example 1-3. Figure 4 Photographs of the control example sample under daylight illumination at 25 °C and under 365 nm ultraviolet lamp irradiation.

[0020] Figure 5 Photographs of the samples of Example 2 and Comparative Example 2 under daylight illumination at 25 °C and under 365 nm ultraviolet lamp irradiation at 25 °C and 150 °C. Among them, (a), (a'), and (a'') are the photographs of the sample of Example 2; (b), (b'), and (b'') are the photographs of the sample of Comparative Example 2.

[0021] Figure 6 Photographs of the samples of Example 3 and Comparative Example 3 under daylight illumination at 25 °C and under 365 nm ultraviolet lamp irradiation at 25 °C and 160 °C. Among them, (a), (a'), and (a'') are the photographs of the sample of Example 3; (b), (b'), and (b'') are the photographs of the sample of Comparative Example 3.

[0022] Figure 7 Photographs of the samples of Example 4 and Comparative Example 4 under daylight illumination at 25 °C and under 365 nm ultraviolet lamp irradiation at 25 °C and 160 °C. Among them, (a), (a'), and (a'') are the photographs of the sample of Example 4; (b), (b'), and (b'') are the photographs of the sample of Comparative Example 4.

[0023] Figure 8 Photographs of the samples of Example 5 and Comparative Example 5 under daylight illumination at 25 °C and under 365 nm ultraviolet lamp irradiation at 25 °C and 150 °C. Among them, (a), (a'), and (a'') are the photographs of the sample of Example 5; (b), (b'), and (b'') are the photographs of the sample of Comparative Example 5. Detailed implementation manners

[0024] The present invention discloses a high-strength yellow fluorescent polyurethane elastomer and a preparation method thereof. The preparation process is as follows: 3,3'-diaminobenzidine and 3,3',4,4'-benzophenone tetracarboxylic dianhydride are respectively dissolved in solvent A, and then the solution of 3,3',4,4'-benzophenone tetracarboxylic dianhydride is dropped into the solution of 3,3'-diaminobenzidine, and reacted at 90 °C for 0.5 - 2 h to obtain an oligomer solution; subsequently, a diisocyanate compound and solvent B are dropped into the DTA solution, and reacted at 100 °C for 0.5 - 1 h to obtain an -NCO functionalized DTA solution; then, solvent C, a polyol compound and a catalyst are added at room temperature, and reacted at 80 °C for 0.5 - 2 h under nitrogen protection to obtain a prepolymer solution; then, the prepolymer solution is cast into a conventional mold, and heat-treated at 50 °C / 12 h + 80 - 100 °C / 4 - 6 h to obtain a polyurethane elastomer film.

[0025] In the above technical solution, the molar ratio of 3,3'-diaminobenzidine : 3,3',4,4'-benzophenone tetracarboxylic dianhydride : diisocyanate compound : polyol compound : catalyst : solvent A : solvent B : solvent C is 2 : 1 : (50 - 65) : (5 - 10) : (0.01 - 0.06) : (100 - 140) : (0 - 130) : (130 - 300).

[0026] In the above technical solution, the polyol includes one or more of polyether polyol and polyester polyol.

[0027] In the above technical solution, the diisocyanate compound includes one or more of isophorone diisocyanate (IPDI), toluene diisocyanate, diphenylmethane diisocyanate, dicyclohexylmethane diisocyanate, hexamethylene diisocyanate (HDI), lysine diisocyanate.

[0028] In the above technical solution, solvent A, solvent B and solvent C are independently selected from one or more of N,N-dimethylformamide (DMF), acetone, ethanol.

[0029] In the above technical solution, the catalyst is organotin (such as dibutyltin dilaurate DBTDL, stannous octoate, etc.), organolead (such as tetraethyllead, triethyllead, etc.).

[0030] In the above technical solution, the prepared polyurethane elastomer not only has a high glass transition temperature (~229 °C) and tensile strength, but also has yellow fluorescence performance and high-temperature fluorescence stability.

[0031] The following specific experiments illustrate the technological progress of the present invention. The raw materials used are all existing products, and the specific preparation operations and performance tests are all conventional techniques. Polytetrahydrofuran (molecular weight 2000, such as brand PTMEG-2000), polyether polyol (molecular weight 2800, such as brand JX230).

[0032] Sample performance test: Glass transition temperature T g Measured by a dynamic thermomechanical analyzer (DMA, Q850, TA Instruments, USA), using the thin film tensile mode, with a frequency of 1 Hz, a heating rate of 3 °C / min, and a sample size of 30 mm × 5 mm × 1 mm. Tensile properties were tested using an electronic universal mechanical testing machine (Z005-TH) on dumbbell-shaped samples with a sample size of 20 mm × 4 mm × 1 mm and a loading rate of 50 mm / min. The fluorescence intensity retention rate of the sample is the percentage of the fluorescence intensity of the sample after heat treatment at a certain temperature for 2 hours (h) to the fluorescence intensity of the untreated sample.

[0033] Example 1 Dissolve 3,3'-diaminobenzidine (2 mmol) and 3,3',4,4'-benzophenone tetracarboxylic dianhydride (1 mmol) in DMF (60 mmol each) solvent respectively, then drop the 3,3',4,4'-benzophenone tetracarboxylic dianhydride solution into the 3,3'-diaminobenzidine solution, and react at 90 °C for 1.5 h to obtain an oligomer (DTA) solution; then add DMF (130 mmol) and HDI (59 mmol), and react at 100 °C for 1.5 h to obtain an -NCO functionalized DTA solution; then add DMF (260 mmol), polytetrahydrofuran PTMEG-2000 (8 mmol) and DBTDL (0.04 mmol) at room temperature, and react at 80 °C for 2 h under nitrogen protection to obtain a prepolymer solution. Cast the solution into a conventional mold and heat-treat it at 50 °C / 12 h + 80 °C / 6 h to obtain a polyurethane elastomer (PUE-DTA) film. The molar ratio of 3,3'-diaminobenzidine: 3,3',4,4'-benzophenone tetracarboxylic dianhydride: diisocyanate compound: polyol compound: catalyst: solvent A: solvent B: solvent C is 2:1:59:8:0.04:120:130:260.

[0034] Comparative Example 1-1 React HDI (59 mmol), DMF (260 mmol), PTMEG-2000 (8 mmol) and DBTDL (0.04 mmol) at 80 °C for 2 h under nitrogen protection to obtain a prepolymer solution. Cast the solution into a conventional mold and heat-treat it at 50 °C / 12 h + 80 °C / 6 h to obtain a polyurethane elastomer film.

[0035] Comparative Example 1-2 Dissolve 3,3',4,4'-benzophenone tetracarboxylic dianhydride (1 mmol) in DMF (60 mmol) solvent, then dropwise add DMF (130 mmol) and HDI (59 mmol), and react at 100 °C for 1.5 h; then add DMF (260 mmol), polytetrahydrofuran PTMEG-2000 (8 mmol) and DBTDL (0.04 mmol) at room temperature, and react at 80 °C for 2 h under nitrogen protection to obtain a prepolymer solution. Cast the solution into a conventional casting mold and heat-treat it at 50 °C / 12 h + 80 °C / 6 h to obtain a polymer film.

[0036] Comparative Examples 1-3 Dissolve 3,3'-diaminobenzidine (2 mmol) in DMF (60 mmol) solvent, then dropwise add DMF (130 mmol) and HDI (59 mmol), and react at 100 °C for 1.5 h; then add DMF (260 mmol), polytetrahydrofuran PTMEG-2000 (8 mmol) and DBTDL (0.04 mmol) at room temperature, and react at 80 °C for 2 h under nitrogen protection to obtain a prepolymer solution. Cast the solution into a conventional casting mold and heat-treat it at 50 °C / 12 h + 80 °C / 6 h to obtain a polymer film.

[0037] Figure 1 are the infrared spectra of 3,3'-diaminobenzidine, 3,3',4,4'-benzophenone tetracarboxylic dianhydride and DTA. Figure 2 are the infrared spectra and fluorescence spectra at different temperatures of the samples of Example 1 and Comparative Examples 1-1. Figure 3 are the photos of the samples of Example 1, Comparative Examples 1-1, DTA's DMF solution, DTA powder, Comparative Example 1-2 and Comparative Example 1-3 under daylight irradiation at 25 °C and under 365 nm ultraviolet lamp radiation at 25 °C and 160 °C.

[0038] Table 1 shows the tensile properties of the samples of Example 1 and Comparative Examples 1-1, 1-2, 1-3, the maximum fluorescence intensity emission wavelengths at different temperatures under an excitation wavelength of 365 nm, and the fluorescence intensity retention rate at high temperatures. See Figure 2 , after the reaction of 3,3'-diaminobenzidine and 3,3',4,4'-benzophenone tetracarboxylic dianhydride, obviously, there is no characteristic absorption peak of acid anhydride (1850 cm -1 and 1770 cm -1 ) in the product DTA, and the characteristic peak of -NH2 (3100 - 3700 cm -1 ) is retained. The characteristic absorption peak of the benzene ring is at 1500 cm -1 , and at 1650 cm -1 and 1720 cm-1 An obvious characteristic absorption peak of C=O in imide (-CONCO-) appeared at 1384 cm -1 And a C-N stretching vibration peak on the imide ring appeared at this position. The above phenomena indicate that the DTA formed by the reaction of 3,3'-diaminobenzidine and 3,3',4,4'-benzophenone tetracarboxylic dianhydride is an oligomer of amino and imide groups. When DTA-NCO reacts with PTMEG, there is no characteristic absorption peak of -NCO in the product PUE-DTA of Example 1 at 2260 cm -1 And there is no characteristic peak of -OH at 3459 cm -1 The absorption peak at 1560 cm -1 Is the characteristic absorption peak of the benzene ring, and the stretching vibration peak of C=O at 1780~1600 cm -1 Is enhanced, indicating that -NCO reacts with -OH to form -NHCOO- groups. Obviously, at 1780~1600 cm -1 And 3330 cm -1 The sample of Example 1 has a stronger C=O bond absorption peak and a wider -NH- characteristic peak than the sample of Comparative Example 1-1, which indicates that the sample of Example 1 may form more -NHCO- groups ( Figure 2 (a) in). At 25°C and 160°C, the maximum fluorescence emission wavelengths (λem) of the sample of Example 1 are 586 nm and 590 nm respectively, corresponding to the yellow light wavelength range; the λem of the sample of Comparative Example 1-1 at 25°C and 160°C are 455 nm and 478 nm respectively ( Figure 2 (b) in), corresponding to the blue light wavelength range, which is completely consistent with the sample photos showing yellow and blue fluorescence respectively under 365 nm ultraviolet lamp irradiation in Example 1 and Comparative Example 1-1 in Figure 3 . The fluorescence intensity retention rate of the sample of Example 1 at 160°C is 95%, and the fluorescence intensity retention rate of the sample of Comparative Example 1-1 is 32% (Table 1), which further indicates that the sample of Example 1 has excellent temperature-resistant fluorescence stability. It can also be seen from Figure 3 That DTA powder and solution do not have fluorescence properties. The sample of Comparative Example 1-2 shows blue-green fluorescence under ultraviolet lamp irradiation, and the sample of Comparative Example 1-3 shows light pink fluorescence under ultraviolet lamp irradiation, which further indicates that the sample of Example 1 is a fluorescent polymer obtained by polymerization reaction. In addition, it can be seen from Table 1 that the sample of Example 1 has both low-temperature T g And high-temperature T g , while Comparative Example 1-1 only has a low-temperature T gMoreover, the tensile strength of the sample of Example 1 was significantly higher than that of the samples of Comparative Example 1-1, Comparative Example 1-2, and Comparative Example 1-3. It can be seen that the sample of Example 1 has a wider application field. In all systems, the mechanical properties of the samples of Comparative Example 1-2 and 1-3 were poor, so other properties were not further given in Table 1.

[0039] Table 1 Tensile properties of the samples of Example 1 and Comparative Examples and maximum emission wavelengths at different temperatures under an excitation wavelength of 365 nm

[0040] Control Example 3,3'-Diaminobenzidine DAB (2 mmol) and 3,3',4,4'-benzophenone tetracarboxylic dianhydride BDTA (1 mmol) were separately dissolved in 60 mmol of DMF. Then, the BDTA solution was dropped into the DAB solution, and the reaction was carried out at 90 °C for 1.5 h to obtain a DTA solution; subsequently, hexamethylene diisocyanate HDI (16 mmol) was dropped into the DTA solution, and the reaction was carried out at 100 °C for 0.5 h to obtain a DTA-NCO solution; then, DMF (130 mmol), polytetrahydrofuran PTMEG-2000 with a molecular weight of 2000 (1.25 mmol), and dibutyltin dilaurate DBTDL (0.04 mmol) were added at room temperature, and the reaction was carried out at 80 °C for 2 h under nitrogen protection. Then, the solution was cast into a mold (conventional method), and a polyurethane elastomer film was obtained by heat treatment at 50 °C / 12 h + 80 °C / 6 h; the molar ratio of DAB:BDTA:diisocyanate compound:polyol compound was 2:1:16:1.25. Figure 4 Photos of the control example sample under daylight irradiation and 365 nm ultraviolet lamp radiation at 25 °C were given. From Figure 4 it can be seen that the control example sample did not produce yellow fluorescence under ultraviolet lamp radiation.

[0041] Example 2 Dissolve 3,3'-diaminobenzidine (2 mmol) and 3,3',4,4'-benzophenone tetracarboxylic dianhydride (1 mmol) separately in DMF (60 mmol each). Then, add the solution of 3,3',4,4'-benzophenone tetracarboxylic dianhydride dropwise to the solution of 3,3'-diaminobenzidine and react at 90 °C for 1.5 h to obtain an oligomer solution. Then, add DMF (130 mmol) and HDI (59 mmol) dropwise and react at 100 °C for 1.5 h to obtain an -NCO functionalized DTA solution. Then, add DMF (300 mmol), polytetrahydrofuran PTMEG-2000 (10 mmol), and DBTDL (0.04 mmol) at room temperature and react at 80 °C for 2 h under nitrogen protection to obtain a prepolymer solution. Cast the solution into a conventional casting mold and heat-treat it at 50 °C / 12 h + 80 °C / 6 h to obtain a polyurethane elastomer film.

[0042] Comparative Example 2 React HDI (59 mmol), DMF (300 mmol), PTMEG-2000 (10 mmol), and DBTDL (0.04 mmol) at 80 °C for 2 h under nitrogen protection to obtain a prepolymer solution. Cast the solution into a mold and heat-treat it at 50 °C / 12 h + 80 °C / 6 h to obtain a polyurethane elastomer film.

[0043] Figure 5 are the photos of the samples of Example 2 and Comparative Example 2 under daylight irradiation at 25 °C and under 365 nm ultraviolet lamp irradiation at 25 °C and 150 °C. Table 2 shows the tensile properties of the samples of Example 2 and Comparative Example 2, the maximum fluorescence intensity emission wavelength at different temperatures under an excitation wavelength of 365 nm, and the fluorescence intensity retention rate at high temperatures. At 25 °C and 150 °C, the fluorescence maximum emission wavelengths (λem) of the samples of Example 2 are 587 nm and 589 nm, respectively, corresponding to the yellow light wavelength range; the λem of the samples of Comparative Example 2 are 453 nm and 475 nm, respectively, corresponding to the blue light wavelength range, which is Figure 5 completely consistent with the photos of the samples of Example 2 and Comparative Example 2 showing yellow and blue fluorescence under 365 nm ultraviolet lamp irradiation, respectively. The fluorescence intensity retention rate of the samples of Example 2 at 160 °C is 97%, and the fluorescence intensity retention rate of the samples of Comparative Example 2 is 39% (Table 2), which further indicates that the samples of Example 2 have excellent temperature-resistant fluorescence stability. In addition, as can be seen from Table 2, the samples of Example 2 have both a low temperature T g and a high temperature T g , while the samples of Comparative Example 2 only have a low temperature T g , and the tensile strength of the samples of Example 2 is significantly higher than that of the samples of Comparative Example 2. It can be seen that the samples of Example 2 have a wider application field.

[0044] Table 2 Tensile properties of the samples of Example 2 and Comparative Example 2 and the maximum emission wavelengths at different temperatures under an excitation wavelength of 365 nm

[0045] Example 3 Dissolve 3,3'-diaminobenzidine (2 mmol) and 3,3',4,4'-benzophenone tetracarboxylic dianhydride (1 mmol) separately in DMF (60 mmol each) solvent. Then, add the solution of 3,3',4,4'-benzophenone tetracarboxylic dianhydride dropwise to the solution of 3,3'-diaminobenzidine, and react at 90 °C for 1.5 h to obtain an oligomer solution; then add DMF (60 mmol) and HDI (59 mmol), and react at 100 °C for 2 h to obtain an -NCO functionalized DTA solution; then add DMF (180 mmol), PTMEG-2000 (7.5 mmol) and DBTDL (0.04 mmol) at room temperature, and react at 80 °C for 2 h under nitrogen protection to obtain a prepolymer solution. Cast the solution into a conventional casting mold, and heat-treat it at 50 °C / 12 h + 80 °C / 6 h to obtain a polyurethane elastomer film.

[0046] Comparative Example 3 Add HDI (59 mmol), DMF (180 mmol), PTMEG-2000 (7.5 mmol) and DBTDL (0.04 mmol), and react at 80 °C for 2 h under nitrogen protection to obtain a prepolymer solution. Cast the solution into a mold, and heat-treat it at 50 °C / 12 h + 80 °C / 6 h to obtain a polyurethane elastomer film.

[0047] Figure 6 are the photos of the samples of Example 3 and Comparative Example 3 under daylight irradiation at 25 °C and under 365 nm UV lamp irradiation at 25 °C and 160 °C. Table 3 shows the tensile properties of the samples of Example 3 and Comparative Example 3, the maximum fluorescence intensity emission wavelengths at different temperatures under an excitation wavelength of 365 nm, and the fluorescence intensity retention rate at high temperatures. At 25 °C and 160 °C, the maximum fluorescence emission wavelengths (λem) of the samples of Example 3 are 578 nm and 580 nm respectively, corresponding to the yellow light wavelength range; the λem of the samples of Comparative Example 3 at 25 °C and 160 °C are 487 nm and 474 nm respectively, corresponding to the blue light wavelength range, which is consistent with Figure 6The photos of the samples in Example 3 and Comparative Example 3 that showed yellow and blue fluorescence respectively under 365 nm UV lamp irradiation were completely consistent. The fluorescence intensity retention rate of the sample in Example 3 at 160 °C was 96%, and that of the sample in Comparative Example 3 was 39% (Table 3), which further demonstrated that the sample in Example 5 had excellent temperature-resistant fluorescence stability. In addition, as can be seen from Table 3, the sample in Example 3 had both low temperature T g and high temperature T g , while Comparative Example 3 only had one low temperature T g , and the tensile strength of the sample in Example 3 was significantly higher than that of the sample in Comparative Example 3. It can be seen that the sample in Example 3 had a broader application field.

[0048] Table 3 Tensile properties of the samples in Example 3 and Comparative Example 3 and the maximum emission wavelength at different temperatures under an excitation wavelength of 365 nm

[0049] Example 4 3,3'-Diaminobenzidine (2 mmol) and 3,3',4,4'-benzophenone tetracarboxylic dianhydride (1 mmol) were respectively dissolved in DMF (70 mmol each) solvent. Then the solution of 3,3',4,4'-benzophenone tetracarboxylic dianhydride was added dropwise to the solution of 3,3'-diaminobenzidine, and the reaction was carried out at 90 °C for 2 h to obtain an oligomer solution; then HDI (59 mmol) was added dropwise, and the reaction was carried out at 100 °C for 2 h to obtain an -NCO-functionalized DTA solution; then PTMEG-2000 (5 mmol) and DBTDL (0.06 mmol) were added at room temperature, and the reaction was carried out at 80 °C for 2 h under nitrogen protection to obtain a prepolymer solution. The solution was cast into a conventional mold and heat-treated at 50 °C / 12 h + 80 °C / 6 h to obtain a polyurethane elastomer film. The molar ratio of 3,3'-diaminobenzidine: 3,3',4,4'-benzophenone tetracarboxylic dianhydride: diisocyanate compound: polyol compound: catalyst: solvent A: solvent B: solvent C was 2:1:59:5:0.06:140:0:0.

[0050] Comparative Example 4 HDI (59 mmol), PTMEG-2000 (5 mmol) and DBTDL (0.04 mmol) were reacted at 80 °C for 2 h under nitrogen protection to obtain a prepolymer solution. The solution was cast into a mold and heat-treated at 50 °C / 12 h + 80 °C / 6 h to obtain a polyurethane elastomer film.

[0051] Figure 7These are the photos of the samples of Example 4 and Comparative Example 4 under daylight lamp irradiation at 25°C and under 365 nm ultraviolet lamp radiation at 25°C and 160°C. Table 4 shows the tensile properties of the samples of Example 4 and Comparative Example 4, the maximum fluorescence intensity emission wavelengths at different temperatures under a 365 nm excitation wavelength, and the fluorescence intensity retention rate at high temperatures. At 25°C and 160°C, the maximum fluorescence emission wavelengths (λem) of the sample of Example 4 are 582 nm and 587 nm respectively, corresponding to the yellow light wavelength range; the λem of the sample of Comparative Example 4 at 25°C and 160°C are 456 nm and 448 nm respectively, corresponding to the blue light wavelength range, which is completely consistent with Figure 7 the photos of the samples of Example 4 and Comparative Example 4 showing yellow and blue fluorescence respectively under 365 nm ultraviolet lamp radiation in g . The fluorescence intensity retention rate of the sample of Example 4 at 160°C is 98%, and the fluorescence intensity retention rate of the sample of Comparative Example 4 is 42% (Table 4), which further shows that the sample of Example 4 has excellent temperature-resistant fluorescence stability. In addition, it can be seen from Table 4 that the sample of Example 4 has both a low temperature T g and a high temperature T g , while the sample of Comparative Example 4 only has a low temperature T

[0052] Table 4 Tensile properties of the samples of Example 4 and Comparative Example 4 and the maximum emission wavelengths at different temperatures under a 365 nm excitation wavelength

[0053] Example 5 3,3'-Diaminobenzidine (2 mmol) and 3,3',4,4'-benzophenone tetracarboxylic dianhydride (1 mmol) were respectively dissolved in DMF (50 mmol each) solvent, and then the solution of 3,3',4,4'-benzophenone tetracarboxylic dianhydride was dropped into the solution of 3,3'-diaminobenzidine, and the reaction was carried out at 90°C for 0.5 h to obtain an oligomer solution; then IPDI (59 mmol) was added dropwise, and the reaction was carried out at 100°C for 0.5 h to obtain an -NCO-functionalized DTA solution; then at room temperature, DMF (100 mmol), acetone (30 mmol), polyether polyol JX230 with a molecular weight of 2800 (5 mmol), and stannous octoate (0.01 mmol) were added, and the reaction was carried out at 80°C for 0.5 h under nitrogen protection to obtain a prepolymer solution. The solution was cast into a conventional mold, and a polyurethane elastomer film was obtained by heat treatment at 50°C / 12 h + 100°C / 4 h.

[0054] Comparative Example 5 IPDI (59 mmol), DMF (100 mol), acetone (30 mmol), polyether polyol JX230 with a molecular weight of 2800 (5 mmol), and stannous octoate (0.01 mmol) were reacted at 80 °C for 0.5 h under nitrogen protection to obtain a prepolymer solution. The solution was cast into a mold and heat-treated at 50 °C / 12 h + 100 °C / 4 h to obtain a polyurethane elastomer film.

[0055] Figure 8 Photographs of the samples of Example 5 and Comparative Example 5 under daylight illumination at 25 °C and under 365 nm ultraviolet lamp radiation at 25 °C and 150 °C are shown. Table 5 shows the tensile properties of the samples of Example 5 and Comparative Example 5, the maximum fluorescence intensity emission wavelengths at different temperatures under a 365 nm excitation wavelength, and the fluorescence intensity retention rate at high temperatures. At 25 °C and 160 °C, the maximum fluorescence emission wavelengths (λem) of the sample of Example 5 were 578 nm and 580 nm, respectively, corresponding to the yellow light wavelength range; the λem of the sample of Comparative Example 5 at 25 °C and 160 °C were 486 nm and 452 nm, respectively, corresponding to the blue light wavelength range, which is in complete agreement with Figure 8 the photographs of the samples of Example 5 and Comparative Example 5 showing yellow and blue fluorescence under 365 nm ultraviolet lamp radiation. The fluorescence intensity retention rate of the sample of Example 5 at 150 °C was 99%. The sample of Comparative Example 5 melted after being treated at 150 °C for 2 h, and its fluorescence intensity retention rate was 42% (Table 5), which further indicates that the sample of Example 5 has excellent temperature-resistant fluorescence stability. In addition, as can be seen from Table 5, the sample of Example 5 has both a low temperature T g and a high temperature T g , while the sample of Comparative Example 5 has only one low temperature T g , and the tensile strength of the sample of Example 5 is significantly higher than that of the sample of Comparative Example 5. It can be seen that the sample of Example 5 has a wider application field.

[0056] Table 5 Tensile properties of the samples of Example 5 and Comparative Example 5 and the maximum emission wavelengths at different temperatures under a 365 nm excitation wavelength

[0057] The fluorescent polyurethane elastomers in the long-wave direction reported in the current literature are mainly prepared by adding fluorescent powders, and their tensile strength is mostly lower than 10 MPa, and the fluorescent properties change with tensile deformation. The polyurethane elastomer prepared by the present invention not only has a high glass transition temperature (~229 °C) and tensile strength, but also has yellow fluorescent properties and high-temperature fluorescent stability. Compared with the prior art, the beneficial effects achieved by the present invention are as follows: The fluorescent polyurethane elastomer of the present invention is a yellow fluorescent polyurethane elastomer constructed based on non-fluorescent pigment substances and fluorescent quantum dots. Compared with the existing fluorescent polyurethane elastomer material system, it not only has good temperature-resistant fluorescent property stability, but also has a longer emission wavelength.

Claims

1. A preparation method of a high-strength yellow fluorescent polyurethane elastomer, comprising the following steps: (1) Using 3,3'-diaminobenzidine and 3,3',4,4'-benzophenone tetracarboxylic dianhydride as raw materials to react and prepare an oligomer; (2) Using the oligomer and a diisocyanate compound as raw materials to react and prepare an isocyanate-functionalized oligomer; (3) Using the isocyanate-functionalized oligomer and a polyol as raw materials, in the presence of a catalyst, to react and prepare a prepolymer; and then curing the prepolymer to obtain a high-strength yellow fluorescent polyurethane elastomer; The molar ratio of 3,3'-diaminobenzidine, 3,3',4,4'-benzophenone tetracarboxylic dianhydride, diisocyanate compound, polyol, and catalyst is 2:(0.8 - 1.2):(50 - 65):(5 - 10):(0.01 - 0.06).

2. The preparation method according to claim 1, characterized in that, The curing is carried out at 40 - 60 °C for 10 - 15 hours, and then at 80 - 100 °C for 4 - 6 h.

3. A preparation method of a prepolymer for a high-strength yellow fluorescent polyurethane elastomer, comprising the following steps: (1) Using 3,3'-diaminobenzidine and 3,3',4,4'-benzophenone tetracarboxylic dianhydride as raw materials to prepare an oligomer; (2) Using the oligomer and a diisocyanate compound as raw materials to prepare an isocyanate-functionalized oligomer; (3) Using the isocyanate-functionalized oligomer and a polyol as raw materials, in the presence of a catalyst, to prepare a prepolymer for a high-strength yellow fluorescent polyurethane elastomer; The molar ratio of 3,3'-diaminobenzidine, 3,3',4,4'-benzophenone tetracarboxylic dianhydride, diisocyanate compound, polyol, and catalyst is 2:(0.8 - 1.2):(50 - 65):(5 - 10):(0.01 - 0.06).

4. The preparation method according to claim 1 or 3, characterized in that, The diisocyanate compound includes one or more of isophorone diisocyanate, toluene diisocyanate, diphenylmethane diisocyanate, dicyclohexylmethane diisocyanate, hexamethylene diisocyanate, and lysine diisocyanate; the polyol includes one or more of polyether polyol and polyester polyol.

5. The preparation method according to claim 1 or 3, characterized in that, The catalyst includes one or more of organotin and organolead.

6. The preparation method according to claim 1 or 3, characterized in that, In step (1), the reaction temperature is 80 - 100 °C and the time is 0.5 - 2 hours; in step (2), the reaction temperature is 90 - 110 °C and the time is 0.5 - 2 hours; in step (3), the reaction temperature is 70 - 90 °C and the time is 0.5 - 2 hours, and the reaction is carried out under a protective atmosphere.

7. A high-strength yellow fluorescent polyurethane elastomer or a prepolymer for a high-strength yellow fluorescent polyurethane elastomer prepared by the preparation method according to claim 1 or 3.

8. The high-strength yellow fluorescent polyurethane elastomer according to claim 7, wherein The glass transition temperature of the high-strength yellow fluorescent polyurethane elastomer is greater than 190 °C, and the tensile strength is not less than 20 MPa.

9. Use of the high-strength yellow fluorescent polyurethane elastomer or the prepolymer for a high-strength yellow fluorescent polyurethane elastomer according to claim 7 as or in the preparation of a high-strength yellow fluorescent material.

10. A high-strength yellow fluorescent material, characterized in that, The preparation raw materials of the high-strength yellow fluorescent material include the high-strength yellow fluorescent polyurethane elastomer or the prepolymer for a high-strength yellow fluorescent polyurethane elastomer according to claim 7.

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