A high-strength yellow fluorescent polyurethane elastomer and its preparation method

Abstract

The present invention discloses a high-strength yellow fluorescent polyurethane elastomer and a preparation method thereof. Using 3,3'-diaminobenzidine and 3,3',4,4'-benzophenone tetracarboxylic dianhydride as raw materials, an oligomer containing an aromatic ring and a hybrid structure with multiple amino groups is synthesized, which reacts with an isocyanate compound to form an -NCO-functionalized oligomer system, and then further reacts with a polyol compound to form a high-strength yellow fluorescent polyurethane elastomer. Compared with existing similar fluorescent polyurethane elastomers, the polyurethane elastomer prepared by the present invention not only has a high glass transition temperature and tensile strength, but also has yellow fluorescence performance and high-temperature fluorescence stability, which is beneficial to its 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 fluorescence performance and poor safety, which will severely inhibit their applications; blending fluorescent molecular substances with polymers will cause uneven dispersion of fluorescent substances and deterioration of fluorescence performance and polymer performance; 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 fluorescence performance will be modified due to the change in the electron transition mode, resulting in the modification of the fluorescence performance of the constructed system. Therefore, it is of great significance to prepare polymer materials with stable fluorescence performance. 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. Currently, in the fluorescent polyurethane elastomer system, the polyurethane polymer system mainly features blue fluorescence, and its fluorescence performance is easily affected by factors such as force and temperature, showing low environmental fluorescence resistance, which further restricts the application of fluorescent polyurethane polymers in harsh environments. Although there are reports in the literature on other fluorescence properties, especially the fluorescence polyurethane system 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 have 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 in existing fluorescent polyurethane elastomers and the lack of a long-wave direction fluorescent polyurethane elastomer system, the present invention introduces an aromatic 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:

[0006] (1) Using 3,3'-diaminobenzidine and 3,3',4,4'-benzophenone tetracarboxylic dianhydride as raw materials, react to prepare oligomers;

[0007] (2) Using the oligomers and diisocyanate compounds as raw materials, react to prepare isocyanate-functionalized oligomers;

[0008] (3) Using the isocyanate-functionalized oligomers and polyols as raw materials, react in the presence of a catalyst to prepare a prepolymer; then cure the prepolymer to obtain a high-strength yellow fluorescent polyurethane elastomer.

[0009] A method for preparing a prepolymer for high-strength yellow fluorescent polyurethane elastomers, comprising the following steps:

[0010] (1) Using 3,3'-diaminobenzidine and 3,3',4,4'-benzophenone tetracarboxylic dianhydride as raw materials, prepare oligomers;

[0011] (2) Using the oligomers and diisocyanate compounds as raw materials, prepare isocyanate-functionalized oligomers;

[0012] (3) Using the isocyanate-functionalized oligomers and polyols as raw materials, prepare a prepolymer for high-strength yellow fluorescent polyurethane elastomers in the presence of a catalyst.

[0013] In the present invention, the molar ratio of 3,3'-diaminobenzidine, 3,3',4,4'-benzophenone tetracarboxylic dianhydride, diisocyanate compounds, polyols, and catalyst is 2:(0.8 - 1.2):(50 - 65):(5 - 10):(0.01 - 0.06).

[0014] In the present invention, the diisocyanate compounds include one or more of isophorone diisocyanate, toluene diisocyanate, diphenylmethane diisocyanate, dicyclohexylmethane diisocyanate, hexamethylene diisocyanate, and lysine diisocyanate; the polyols include one or more of polyether polyols and polyester polyols; the catalysts include one or more of organotin and organolead.

[0015] 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.

[0016] 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 hours.

[0017] The present invention discloses a high-strength yellow fluorescent polyurethane elastomer prepared according to the above preparation method or a prepolymer for a high-strength yellow fluorescent polyurethane elastomer. Preferably, the glass transition temperature of the high-strength yellow fluorescent polyurethane elastomer is greater than 190 °C, even greater than 220 °C, and the tensile strength is not less than 20 MPa.

[0018] The present invention discloses the application of the above high-strength yellow fluorescent polyurethane elastomer or the prepolymer for a high-strength yellow fluorescent polyurethane elastomer in being or preparing a high-strength yellow fluorescent material.

[0019] The present invention discloses a high-strength yellow fluorescent material, and its preparation raw materials include the above high-strength yellow fluorescent polyurethane elastomer or the prepolymer for a high-strength yellow fluorescent polyurethane elastomer.

[0020] 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; subsequently, 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. The molar ratio of 3,3'-diaminobenzidine, 3,3',4,4'-benzophenone tetracarboxylic dianhydride, the diisocyanate compound, the polyol compound, the 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).

[0021] 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 properties and high-temperature fluorescence stability.

[0022] 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 properties, but also has a longer emission wavelength. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is the infrared spectra of 3,3'-diaminobenzidine, 3,3',4,4'-benzophenone tetracarboxylic dianhydride and DTA.

[0024] Figure 2 Infrared spectra and fluorescence (PL) spectra (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.

[0025] Figure 3 Photographs of the samples of Example 1, Comparative Example 1-1, DMF solution of DTA, DTA powder, Comparative Example 1-2 and Comparative Example 1-3 under daylight illumination at 25 °C and ultraviolet lamp radiation at 365 nm 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.

[0026] Figure 4 Photographs of the control sample under daylight illumination at 25 °C and ultraviolet lamp radiation at 365 nm.

[0027] Figure 5 Photographs of the samples of Example 2 and Comparative Example 2 under daylight illumination at 25 °C and ultraviolet lamp radiation at 365 nm 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.

[0028] Figure 6 Photographs of the samples of Example 3 and Comparative Example 3 under daylight illumination at 25 °C and ultraviolet lamp radiation at 365 nm 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.

[0029] Figure 7 Photographs of the samples of Example 4 and Comparative Example 4 under daylight illumination at 25 °C and ultraviolet lamp radiation at 365 nm 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.

[0030] Figure 8Photographs of the samples of Example 5 and Comparative Example 5 under daylight lamp irradiation at 25°C and under 365 nm ultraviolet lamp radiation at 25°C and 150°C, where (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 mode

[0031] 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.

[0032] 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).

[0033] In the above technical solution, the polyol includes one or more of polyether polyol and polyester polyol.

[0034] 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), and lysine diisocyanate.

[0035] 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, and ethanol.

[0036] In the above technical solution, the catalyst is an organotin (such as dibutyltin dilaurate DBTDL, stannous octoate, etc.) or an organolead (such as tetraethyllead, triethyllead, etc.).

[0037] 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.

[0038] The following specific experiments illustrate the technical progress of the present invention. The raw materials used are all existing products, and the specific preparation operations and performance tests are all conventional technologies. Poly(tetramethylene ether) glycol (with a molecular weight of 2000, such as the brand PTMEG-2000), polyether polyol (with a molecular weight of 2800, such as the brand JX230).

[0039] 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, 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.

[0040] Example 1

[0041] 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 drop 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), poly(tetramethylene ether) glycol 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.

[0042] Comparative Example 1-1

[0043] HDI (59 mmol), DMF (260 mmol), PTMEG-2000 (8 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 conventional casting mold and heat-treated at 50 °C / 12 h + 80 °C / 6 h to obtain a polyurethane elastomer film.

[0044] Comparative Example 1-2

[0045] 3,3',4,4'-Benzophenone tetracarboxylic dianhydride (1 mmol) was dissolved in DMF (60 mmol) solvent, and then DMF (130 mmol) and HDI (59 mmol) were added dropwise. The reaction was carried out at 100 °C for 1.5 h; then at room temperature, DMF (260 mmol), polytetrahydrofuran PTMEG-2000 (8 mmol) and DBTDL (0.04 mmol) were added, 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 casting mold and heat-treated at 50 °C / 12 h + 80 °C / 6 h to obtain a polymer film.

[0046] Comparative Example 1-3

[0047] 3,3'-Diaminobenzidine (2 mmol) was dissolved in DMF (60 mmol) solvent, and then DMF (130 mmol) and HDI (59 mmol) were added dropwise. The reaction was carried out at 100 °C for 1.5 h; then at room temperature, DMF (260 mmol), polytetrahydrofuran PTMEG-2000 (8 mmol) and DBTDL (0.04 mmol) were added, 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 casting mold and heat-treated at 50 °C / 12 h + 80 °C / 6 h to obtain a polymer film.

[0048] Figure 1 It is the infrared spectra of 3,3'-diaminobenzidine, 3,3',4,4'-benzophenone tetracarboxylic dianhydride and DTA. Figure 2 It is the infrared spectra and fluorescence spectra at different temperatures of the samples of Example 1 and Comparative Example 1-1. Figure 3 It is the photos of the samples of Example 1, Comparative Example 1-1, DMF solution of DTA, DTA powder, Comparative Example 1-2 and Comparative Example 1-3 under daylight irradiation at 25 °C, and under 365 nm ultraviolet lamp irradiation at 25 °C and 160 °C.

[0049] Table 1 shows the tensile properties of the samples of Example 1 and Comparative Example 1-1, Comparative Example 1-2, Comparative Example 1-3, the maximum fluorescence intensity emission wavelength at different temperatures under an excitation wavelength of 365 nm, and the fluorescence intensity retention rate at high temperature. See Figure 2, when 3,3'-diaminobenzidine reacts with 3,3',4,4'-benzophenone tetracarboxylic dianhydride, obviously, there is no characteristic absorption peak of anhydride (1850 cm -1 and 1770 cm -1 ) in the product DTA, and the characteristic peak of -NH2 (3100 - 3700 cm -1 ) is retained. There is a characteristic absorption peak of the benzene ring at 1500 cm -1 , and obvious C=O characteristic absorption peaks of imide (-CONCO-) appear at 1650 cm -1 and 1720 cm -1 . A C-N stretching vibration peak on the imide ring appears at 1384 cm -1 . 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 at 2260 cm -1 in the product PUE-DTA of Example 1, and there is no characteristic peak of -OH at 3459 cm -1 . The characteristic absorption peak of the benzene ring is at 1560 cm -1 . 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 broader -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)). 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)), corresponding to the blue light wavelength range, which is completely consistent with the photos of the samples of Example 1 and Comparative Example 1-1 showing yellow and blue fluorescence respectively under 365 nm ultraviolet lamp irradiation 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. From Figure 3It can also be seen that the DTA powder and solution do not have fluorescence properties. In contrast, the samples of Comparative Examples 1-2 show blue-green fluorescence under ultraviolet lamp irradiation, and the samples of Comparative Examples 1-3 show light pink fluorescence under ultraviolet lamp irradiation. This further indicates that the sample of Example 1 is a fluorescent polymer obtained through a polymerization reaction. In addition, as can be seen from Table 1, the sample of Example 1 has both a low-temperature T g and a high-temperature T g , while Comparative Example 1-1 only has a low-temperature T g . Moreover, the tensile strength of the sample of Example 1 is significantly higher than that of the samples of Comparative Examples 1-1, Comparative Examples 1-2, and Comparative Examples 1-3. It can be seen that the sample of Example 1 has a broader application field. In all systems, the mechanical properties of the samples of Comparative Examples 1-2 and 1-3 are poor, so other properties are not further given in Table 1.

[0050] Table 1 Tensile properties of the samples of Example 1 and Comparative Examples and the maximum emission wavelength at different temperatures under an excitation wavelength of 365 nm

[0051]

[0052] Control Example

[0053] Dissolve 3,3'-diaminobenzidine DAB (2 mmol) and 3,3',4,4'-benzophenone tetracarboxylic dianhydride BDTA (1 mmol) in 60 mmol of DMF respectively. Then, drop the BDTA solution into the DAB solution and react at 90 °C for 1.5 h to obtain a DTA solution; subsequently, drop hexamethylene diisocyanate HDI (16 mmol) into the DTA solution and react at 100 °C for 0.5 h to obtain a DTA-NCO solution; then, add DMF (130 mmol), polytetrahydrofuran PTMEG-2000 with a molecular weight of 2000 (1.25 mmol), and dibutyltin dilaurate DBTDL (0.04 mmol) at room temperature, and react at 80 °C for 2 h under nitrogen protection. Then, pour the solution into a mold (conventional method) and heat-treat it at 50 °C / 12 h + 80 °C / 6 h to obtain a polyurethane elastomer film; the molar ratio of DAB:BDTA:diisocyanate compound:polyol compound is 2:1:16:1.25. Figure 4 Pictures of the control example sample under daylight irradiation and 365 nm ultraviolet lamp irradiation at 25 °C are given. As can be seen from Figure 4 , the control example sample does not produce yellow fluorescence under ultraviolet lamp irradiation.

[0054] Example 2

[0055] 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.

[0056] Comparative Example 2

[0057] 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.

[0058] Figure 5 are photos of the samples of Example 2 and Comparative Example 2 under daylight irradiation at 25 °C and under 365 nm UV lamp radiation 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 wavelengths 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 sample of Example 2 are 587 nm and 589 nm, respectively, corresponding to the yellow light wavelength range; the λem of the sample of Comparative Example 2 at 25 °C and 150 °C are 453 nm and 475 nm, respectively, corresponding to the blue light wavelength range, which is completely consistent with Figure 5 the photos of the samples of Example 2 and Comparative Example 2 showing yellow and blue fluorescence under 365 nm UV lamp radiation, respectively. The fluorescence intensity retention rate of the sample of Example 2 at 160 °C is 97%, and the fluorescence intensity retention rate of the sample of Comparative Example 2 is 39% (Table 2), which further shows that the sample of Example 2 has excellent temperature-resistant fluorescence stability. In addition, as can be seen from Table 2, the sample of Example 2 has both a low-temperature T g and a high-temperature T g , while Comparative Example 2 only has a low-temperature T gMoreover, the tensile strength of the sample of Example 2 is significantly higher than that of the sample of Comparative Example 2. It can be seen that the sample of Example 2 has a broader application field.

[0059] Table 2 Tensile properties of the samples of Example 2 and Comparative Example 2 and the maximum emission wavelengths at different temperatures under the excitation wavelength of 365 nm

[0060]

[0061] Example 3

[0062] Dissolve 3,3'-diaminobenzidine (2 mmol) and 3,3',4,4'-benzophenone tetracarboxylic dianhydride (1 mmol) in DMF (60 mmol each) solvent respectively. 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) dropwise 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.

[0063] Comparative Example 3

[0064] 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.

[0065] Figure 6 are photos of the samples of Example 3 and Comparative Example 3 under daylight irradiation at 25 °C and under 365 nm ultraviolet 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 the 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 sample of Example 3 are 578 nm and 580 nm respectively, corresponding to the yellow light wavelength range; the λem of the sample 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 radiation 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.

[0066] 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

[0067]

[0068] Example 4

[0069] Dissolve 3,3'-diaminobenzidine (2 mmol) and 3,3',4,4'-benzophenone tetracarboxylic dianhydride (1 mmol) separately in DMF (70 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 2 h to obtain an oligomer solution; then add HDI (59 mmol) dropwise and react at 100 °C for 2 h to obtain an -NCO-functionalized DTA solution; then add PTMEG-2000 (5 mmol) and DBTDL (0.06 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. 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 2:1:59:5:0.06:140:0:0.

[0070] Comparative Example 4

[0071] Add HDI (59 mmol), PTMEG-2000 (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.

[0072] Figure 7These are 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 showing yellow and blue fluorescence respectively under 365 nm ultraviolet lamp radiation in Example 4 and Comparative Example 4 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, as can be seen from Table 4, the sample of Example 4 has both a low-temperature T g and a high-temperature T g , while Comparative Example 4 only has a low-temperature T

[0073] Table 4 Tensile properties of the samples of Example 4 and Comparative Example 4 and maximum emission wavelengths at different temperatures under a 365 nm excitation wavelength

[0074]

[0075] Example 5

[0076] Dissolve 3,3'-diaminobenzidine (2 mmol) and 3,3',4,4'-benzophenone tetracarboxylic dianhydride (1 mmol) in DMF (50 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 0.5 h to obtain an oligomer solution; then add IPDI (59 mmol) dropwise and react at 100°C for 0.5 h to obtain an -NCO-functionalized DTA solution; then add DMF (100 mmol), acetone (30 mmol), polyether polyol JX230 with a molecular weight of 2800 (5 mmol), and stannous octoate (0.01 mmol) at room temperature, and react at 80°C for 0.5 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 + 100°C / 4 h to obtain a polyurethane elastomer film.

[0077] Comparative Example 5

[0078] 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.

[0079] Figure 8 are the photos of the samples of Example 5 and Comparative Example 5 under daylight irradiation at 25 °C and under 365 nm ultraviolet lamp irradiation at 25 °C and 150 °C. 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 are 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 are 486 nm and 452 nm, respectively, corresponding to the blue light wavelength range, which is Figure 8 completely consistent with the photos of the samples of Example 5 and Comparative Example 5 showing yellow and blue fluorescence samples under 365 nm ultraviolet lamp irradiation. The fluorescence intensity retention rate of the sample of Example 5 at 150 °C is 99%. The sample of Comparative Example 5 melts after being treated at 150 °C for 2 h, and its fluorescence intensity retention rate is 42% (Table 5), which further shows 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 broader application field.

[0080] 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

[0081]

[0082] The fluorescent polyurethane elastomers in the long-wave direction reported in the current literature mainly add fluorescent powders, and their tensile strength is mostly lower than 10 MPa, and the fluorescence properties change with tensile deformation. The polyurethane elastomer prepared in the present invention not only has a high glass transition temperature (~229 °C) and tensile strength, but also has yellow fluorescence properties and high-temperature fluorescence stability. Compared with the prior art, the beneficial effects achieved 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 existing fluorescent polyurethane elastomer material system, it not only has good stability of temperature-resistant fluorescence properties, but also has a longer emission wavelength.

Claims

1. A method for preparing a high-intensity yellow fluorescent polyurethane elastomer, comprising the following steps: (1) Using 3,3'-diaminobenzidine and 3,3',4,4'-benzophenonetetracarboxylic dianhydride as raw materials, the oligomer is prepared by reaction; (2) using the oligomer and diisocyanate compound as raw materials to react and prepare an isocyanate functionalized oligomer; (3) Using isocyanate functionalized oligomers and polyols as raw materials, a prepolymer is prepared by reaction in the presence of a catalyst; the prepolymer is then cured to obtain a high-intensity yellow fluorescent polyurethane elastomer; The molar ratio of 3,3'-diaminobenzidine, 3,3',4,4'-benzophenonetetracarboxylic 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 Curing is 40-60℃ for 10-15 hours, then 80-100℃ for 4-6 hours.

3. A method for preparing a prepolymer for a high-intensity yellow fluorescent polyurethane elastomer, comprising the following steps: (1) Using 3,3'-diaminobenzidine and 3,3',4,4'-benzophenonetetracarboxylic dianhydride as raw materials, oligomers were prepared; (2) preparing an isocyanate functionalized oligomer using the oligomer and diisocyanate compound as raw materials; (3) Using isocyanate functionalized oligomers and polyols as raw materials, in the presence of a catalyst, a high-intensity yellow fluorescent polyurethane elastomer prepolymer was prepared; The molar ratio of 3,3'-diaminobenzidine, 3,3',4,4'-benzophenonetetracarboxylic 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 organic tin and organic lead.

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 reaction time is 0.5-2 hours; in step (2), the reaction temperature is 90-110°C and the reaction time is 0.5-2 hours; in step (3), the reaction temperature is 70-90°C and the reaction time is 0.5-2 hours, and the reaction is carried out under a protective atmosphere.

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

8. The high-intensity yellow fluorescent polyurethane elastomer according to claim 7, characterized in that: The high-intensity yellow fluorescent polyurethane elastomer has a glass transition temperature greater than 190° C. and a tensile strength not less than 20 MPa.

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

10. A high-intensity yellow fluorescent material, characterized in that: The raw materials for preparing the high-intensity yellow fluorescent material include the high-intensity yellow fluorescent polyurethane elastomer or the prepolymer for high-intensity yellow fluorescent polyurethane elastomer as claimed in claim 7.

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