Sunlight response high-strength self-repairing polyurethane material and preparation method thereof

Abstract

The invention discloses a sunlight response high-strength self-repairing polyurethane material and a preparation method thereof, and belongs to the technical field of self-repairing materials, the sunlight response high-strength self-repairing polyurethane material is obtained by coordinating polyurethane containing an azothiazole structure and metal ions according to a certain proportion, the polyurethane containing the azothiazole structure is prepared by stirring diisocyanate, diol containing the azothiazole structure, long-chain diol and aminophenylboronic acid according to a certain proportion in N, N-dimethylformamide at room temperature to react for 5 hours. According to the invention, a photoactive azothiazole structure is introduced into polyurethane, and reversible metal coordination bonds are formed by the azothiazole structure and metal ions, so that rapid sunlight response self-repairing of the polyurethane material is realized. The self-repairing efficiency of the prepared photoresponse self-repairing polyurethane material is 95.1% after the photoresponse self-repairing polyurethane material is irradiated by sunlight for 2 h, and the photoresponse self-repairing polyurethane material has rapid photoresponse self-repairing performance and has wide application prospects in the fields of self-repairing coatings, intelligent coatings and anti-corrosion coatings.

Description

Technical Field

[0001] The present invention relates to the technical field of self - healing materials, and particularly to a sunlight - responsive high - strength self - healing polyurethane material and a preparation method thereof. Background Art

[0002] During the use of polymer materials, it is inevitable that the materials are damaged due to friction, collision, etc., which reduces the use performance of the materials and shortens their service life. Self - healing materials can undergo reversible cleavage and formation of covalent or non - covalent bonds under the stimulation of heat, light, humidity, pH, chemical reagents, etc., to achieve the repair of damaged positions, improve the use safety of the materials, and extend their service life. Photo - responsive self - healing materials have the characteristics of instantaneous switching, remote control, and precise positioning, and have received more and more attention from researchers. The reported photo - responsive self - healing materials generally have the disadvantages of low repair efficiency, low mechanical strength, the need for light irradiation with a specific wavelength, and high surface temperature of the materials, which limit the application of photo - responsive self - healing materials.

[0003] The present invention introduces an azothiazole structure into polyurethane, adds appropriate metal ions to form metal coordination bonds with the azothiazole structure, and prepares a sunlight - responsive high - strength self - healing polyurethane material. Under sunlight irradiation, the reversible cleavage and formation of metal coordination bonds endow the polyurethane material with excellent self - healing performance. Summary of the Invention

[0004] In order to solve the problems of low repair efficiency, the need for light irradiation with a specific wavelength, and low mechanical strength of existing photo - responsive self - healing materials, the present invention proposes a sunlight - responsive high - strength self - healing polyurethane material and a preparation method thereof.

[0005] To achieve the above object, the present invention adopts the following technical solutions: A sunlight - responsive high - strength self - healing polyurethane material and a preparation method thereof, characterized in that the polyurethane material is obtained by coordinating a polyurethane containing an azothiazole structure with metal ions, and the molar ratio of the azothiazole structure to the metal ions in the polyurethane containing the azothiazole structure is 1:0.15 - 0.5. The polyurethane containing the azothiazole structure is obtained by reacting a diisocyanate, a diol containing an azothiazole structure, a long - chain diol, and aminophenylboronic acid in a molar ratio of 1:0.5 - 0.8:0.2 - 0.5:0.03 - 0.15. The structural general formula of the polyurethane is:

[0006] In the formula, the value range of m is 1 - 6, and the value range of n is 3 - 40; In the formula, R1 is one or more of the following structural formulas;

[0007] In the formula, R2 is one or more of the following structural formulas;

[0008] In the formula, the value range of x is 1 to 30; Further, for the sunlight-responsive high-strength self-healing polyurethane material and its preparation method, it is characterized in that the metal ions are selected from one or more of ferric trichloride, zinc chloride, copper chloride, ferric nitrate, zinc nitrate, copper nitrate, terbium trifluoromethanesulfonate, zinc trifluoromethanesulfonate, europium trifluoromethanesulfonate; Further, for the sunlight-responsive high-strength self-healing polyurethane material and its preparation method, it is characterized in that the aminophenylboronic acid is one or more of 2-aminophenylboronic acid, 3-aminophenylboronic acid, and 4-aminophenylboronic acid; For the sunlight-responsive high-strength self-healing polyurethane material and its preparation method, it is characterized in that the general structural formula of the diol containing an azothiazole structure is as follows:

[0009] In the formula, the value range of m is 1 to 6; Further, for the sunlight-responsive high-strength self-healing polyurethane material and its preparation method, it is characterized by including the following steps: S1. Preparation of diol containing an azothiazole structure: Add diphenol containing an azothiazole structure, chloro-substituted alkyl alcohol, potassium carbonate, and potassium iodide into a round-bottom flask according to a molar ratio of 1:2.2:2.4:0.4, dissolve with N, N-dimethylformamide, and stir and react at 80 °C for 10 hours. After the reaction ends, the diol containing an azothiazole structure is obtained through extraction, washing, and drying; S2. Preparation of polyurethane containing an azothiazole structure: Under nitrogen protection, dissolve diisocyanate, diol containing an azothiazole structure, and long-chain diol with N, N-dimethylformamide, add the catalyst dibutyltin dilaurate, react at room temperature for 3 to 4 hours, add aminophenylboronic acid and continue to react for 1 to 2 hours to obtain polyurethane containing an azothiazole structure. The molar ratio of diisocyanate, diol containing an azothiazole structure, long-chain diol, and aminophenylboronic acid is 1:0.5 to 0.8:0.2 to 0.5:0.03 to 0.15; S3. Preparation of sunlight-responsive high-strength self-healing polyurethane material: Dissolve the polyurethane containing an azothiazole structure in tetrahydrofuran, then add a methanol solution of metal salt, and stir overnight at room temperature. The molar ratio of the azothiazole group in the polyurethane to the metal ion is 1:0.15 to 0.5. After the reaction ends, pour the mixed solution into a mold and dry the solvent in an oven to obtain the sunlight-responsive high-strength self-healing polyurethane material.

[0010] Compared with the prior art, the beneficial effects of the present invention are as follows: First, by introducing an azothiazole structure into the polyurethane, the reversible cleavage and formation of the metal coordination bond formed by azothiazole and metal ions under sunlight irradiation endow the polyurethane material with excellent self-healing performance, and the self-healing efficiency reaches 95.1%. The self-healing material prepared by the present invention uses sunlight as the stimulation source, solving the problem that the existing light-responsive self-healing materials need to be irradiated with light of a specific wavelength to achieve self-healing of the material, and the self-healing operation is simpler.

[0011] Second, the present invention uses a bifunctional diol containing an azothiazole structure as the functional monomer and aminophenylboronic acid as the crosslinking agent to prepare a crosslinked polyurethane containing an azothiazole structure on the main chain, significantly improving the mechanical properties of the polyurethane and overcoming the problem of poor mechanical properties of the existing light-responsive self-healing materials, realizing that the light-responsive self-healing materials have high mechanical properties while maintaining high repair efficiency.

[0012] Other advantages, objectives and features of the present invention will be partially reflected by the following description and partially understood by those skilled in the art through the research and practice of the present invention. Description of the Drawings

[0013] Figure 1 is the 1H NMR spectrum of the diol containing an azothiazole structure.

[0014] Figure 2 is the infrared spectrum of the diol containing an azothiazole structure.

[0015] Figure 3 is the infrared spectrum of polyurethane PMHA-1.

[0016] Figure 4 is the UV-Vis absorption spectrum of polyurethane PMHA-1.

[0017] Figure 5 is the differential scanning calorimetry chart of polyurethane PMHA-1.

[0018] Figure 6 is the tensile curve of polyurethane PMHA-1 before and after visible light-responsive repair.

[0019] Figure 7 is the tensile curve of polyurethane PMHA-1 before and after sunlight-responsive repair.

[0020] Figure 8 is the infrared spectrum of polyurethane PMHA-2.

[0021] Figure 9 is the differential scanning calorimetry chart of polyurethane PMHA-2.

[0022] Figure 10 It is the tensile curve graph of polyurethane PMHA-2 before and after visible light response repair. Specific implementation manners

[0023] The following is an illustration of the preferred implementation cases of the present invention in conjunction with the attached drawings. It should be understood that the preferred implementation cases described herein are only used to illustrate and explain the present invention and are not used to limit the present invention.

[0024] Example 1

[0025] (1) Preparation of diol containing azothiazole structure: 3 g (10.66 mmol) of diphenol containing azothiazole structure, 3.2 g (23.42 mmol) of chlorohexanol, 3.53 g (25.57 mmol) of potassium carbonate, and 0.71 g (4.27 mmol) of potassium iodide were added to a 100 mL single-necked flask and dissolved with N,N-dimethylformamide. The reaction was carried out under reflux condensation at 80 °C for 10 hours with a rotation speed of 350 r / min. Subsequently, it was extracted with ethyl acetate, washed three times with 1 mol / L sodium hydroxide aqueous solution, washed three times with water, and washed three times with saturated brine. The organic layer was dried with anhydrous sodium sulfate for 2 h and then rotary evaporated to obtain diol containing azothiazole structure. The reaction equation is as follows:

[0026] Figure 1 It is the nuclear magnetic resonance hydrogen spectrum of diol containing azothiazole structure 1 H NMR (400 MHz, Chloroform-d) δ 8.05-7.99 (Ar-H), 7.29 (Ar-H), 7.09 (Ar-H), 7.04-7.00 (Ar-H), 4.07 (HO-C-H), 3.71-3.63 (-O-C-H), 1.91-1.80 (-CH2), 1.68-1.42 (-CH2), which proves its successful preparation.

[0027] Figure 2 It is the infrared spectrum of diol containing azothiazole structure. The infrared absorption peaks are respectively 3282 cm -1 (-OH), 2936 cm -1 , 2862 cm -1 (-CH2), 1593 cm -1 , 1494 cm -1 , 1465 cm -1 (Ar), 1388 cm -1 (C-N), 1136cm-1 (C-O-C), proving its successful preparation.

[0028] (2) Preparation of polyurethane containing azothiazole structure: At room temperature, 1 g (2.5 mmol) of PEG400 after water removal was added to a 50 mL round-bottom flask. Subsequently, 2 mL of a DMF solution containing 0.855 g (3.4 mmol) of MDI was added. After stirring at 350 r / min at room temperature for 5 min, DBTDL was added. After 20 min, the viscosity increased sharply. 1 mL of DMF from a wash bottle was added, and 3 mL of DMF was added again for dilution. After 10 min, 2 mL of a DMF solution containing 0.3925 g (0.83 mmol) of diol with azothiazole structure was added. After reacting for 4 h, 0.0228 g (0.16 mmol) of 2-aminophenylboronic acid was added and reacted for 1 h. After the reaction, it was poured into a mold to form a film.

[0029] (3) Preparation of a high-strength self-healing polyurethane material with sunlight response: The polyurethane containing azothiazole structure was dissolved in N, N-dimethylformamide, and then a methanol solution of zinc trifluoromethanesulfonate was added. It was stirred overnight at room temperature. The molar ratio of the azothiazole group in the polyurethane to zinc trifluoromethanesulfonate was 1:0.5. After the reaction, the mixture was poured into a mold and the solvent was dried in an oven to obtain the high-strength self-healing polyurethane material PMHA-1 with sunlight response.

[0030] Figure 3 is the infrared spectrum of polyurethane PMHA-1. The infrared absorption peaks are 3302 cm -1 (-NH-), 2924 cm -1 、2862 cm -1 (-CH2), 1723 cm -1 (-C=O), 1598 cm -1 、1535 cm -1 (Ar), 1310 cm -1 (C-N), 1136cm -1 (C-O-C), proving the successful preparation of polyurethane PMHA-1.

[0031] Figure 4It is the ultraviolet-visible absorption spectrum of polyurethane PMHA-1. There is a trans absorption peak of the azobenzothiazole structure at around 430 nm, and a cis absorption peak of the azobenzothiazole structure at around 550 nm. After 60 s of blue light irradiation at 450 nm, since the trans structure changes to the cis structure, the peak at 430 nm decreases and the peak at 550 nm increases. Subsequently, after 10 s of green light irradiation at 550 nm, the cis changes to the trans, the peak at 430 nm increases, and the peak at 550 nm decreases, proving the visible light response behavior of this polyurethane.

[0032] Figure 5 It is the differential scanning calorimetry chart of polyurethane PMHA-1. It can be seen that the glass transition temperature of PMHA-1 is 18.48 °C.

[0033] Figure 6 It is the tensile curve graph of polyurethane PMHA-1 before and after visible light response repair. As can be seen from the figure, the tensile stress of the initial spline is 7.34 MPa, and the elongation at break is 645%. After 10 min of visible light irradiation at 450 nm and 10 min of visible light irradiation at 550 nm, the tensile stress of the repaired PMHA-1 is 7.26 MPa, and the elongation at break is 641%. Its strength self-healing efficiency is 98.9%, and its strain self-healing efficiency is 99.3%.

[0034] Figure 7 It is the tensile curve graph of polyurethane PMHA-1 before and after sunlight response repair. As can be seen from the figure, the initial tensile strength of the spline is 7.34 MPa, and the elongation at break is 645%. After 5 h of sunlight repair, its tensile stress is 6.94 MPa, and the elongation at break is 634%. Its strength self-healing efficiency is 95.1%, and its strain self-healing efficiency is 98.2%.

[0035] Example 2

[0036] The method for preparing the diol containing azothiazole structure is the same as step (1) in Example 1. (2) Preparation of polyurethane containing azothiazole structure: At room temperature, 0.4 g (1 mmol) of water-free PEG400 was added to a 50 mL round-bottom flask, and then 2 mL of a DMF solution containing 0.3878 g (1.55 mmol) of MDI was added. After stirring at 350 r / min at room temperature for 5 min, DBTDL was added. The viscosity increased sharply 20 min after addition. 1 mL of DMF from a wash bottle was added, and then 3 mL of DMF was added again for dilution. 10 min later, 2 mL of a DMF solution containing 0.2355 g (0.5 mmol) of a diol with an azothiazole structure was added. After reacting for 4 h, 0.0137 g (0.1 mmol) of 2-aminophenylboronic acid was added and reacted for 1 h. After the reaction was completed, it was poured into a mold to form a film.

[0037] (3) Preparation of a sunlight-responsive high-strength self-healing polyurethane material: The polyurethane containing an azothiazole structure was dissolved in N,N-dimethylformamide, and then a methanol solution of zinc trifluoromethanesulfonate was added, and it was stirred overnight at room temperature. The molar ratio of the azothiazole group in the polyurethane to zinc trifluoromethanesulfonate was 1:0.5. After the reaction was completed, the mixture was poured into a mold and the solvent was dried in an oven to obtain the sunlight-responsive high-strength self-healing polyurethane material PMHA-2.

[0038] Figure 8 is the infrared spectrum of the sunlight-responsive high-strength self-healing polyurethane PMHA-2. The infrared absorption peaks are respectively 3307 cm -1 (-NH-), 2920 cm -1 、2854 cm -1 (-CH2), 1727 cm -1 (-C=O), 1598 cm -1 、1535 cm -1 (Ar), 1307 cm -1 (C-N), 1136 cm -1 (C-O-C), which proves the successful preparation of the polyurethane PMHA-1.

[0039] Figure 9 is the differential scanning calorimetry chart of the polyurethane PMHA-2. It can be seen that the glass transition temperature of PMHA-1 is 36.17 °C.

[0040] Figure 10It is the tensile curve of the sunlight-responsive high-strength self-healing polyurethane before and after light-responsive repair. As can be seen from the figure, the tensile stress of the initial spline is 3.08 MPa, and the elongation at break is 292%. After irradiating with 450 nm visible light for 40 min and 550 nm visible light for 40 min, the tensile strength of PMHA-2 after repair is 2.76 MPa, the elongation at break is 285%, the self-healing efficiency of strength is 89.6%, and the self-healing efficiency of strain is 97.6%.

[0041] Example 3

[0042] The method for preparing the diol containing an azothiazole structure is the same as step (1) in Example 1 (2) Preparation of polyurethane containing an azothiazole structure: At room temperature, add 0.4 g (1 mmol) of PCL400 dehydrated to a 50 mL round-bottom flask, and then add 2 mL of a DMF solution containing 0.5255 g (2.1 mmol) of MDI. Stir at room temperature at a speed of 350 r / min for 5 min, then add DBTDL. After 20 min, the viscosity increases sharply. Add 1 mL of DMF from a wash bottle and add another 3 mL of DMF for dilution. After 10 min, add 0.471 g (1 mmol) of a 2 mL DMF solution of the diol containing an azothiazole structure. After reacting for 4 h, add 0.0273 g (0.2 mmol) of 3-aminophenylboronic acid and react for 1 h. After the reaction is completed, pour it into a mold to form a film.

[0043] (3) Preparation of sunlight-responsive high-strength self-healing polyurethane material: Dissolve the polyurethane containing an azothiazole structure in N,N-dimethylformamide, then add a methanol solution of terbium trifluoromethanesulfonate and stir overnight at room temperature. The molar ratio of the azothiazole group in the polyurethane to terbium trifluoromethanesulfonate is 1:0.5. After the reaction is completed, pour the mixture into a mold and dry the solvent in an oven to obtain the sunlight-responsive high-strength self-healing polyurethane material.

[0044] Example 4

[0045] The method for preparing the diol containing an azothiazole structure is the same as step (1) in Example 1 (2) Preparation of polyurethane containing an azothiazole structure: At room temperature, 0.4 g (1 mmol) of water-free PEG400 was added to a 50 mL round-bottom flask. Subsequently, 2 mL of a DMF solution containing 0.3532 g (2.1 mmol) of HDI was added. After stirring at 350 r / min at room temperature for 5 min, DBTDL was added. The viscosity increased sharply 20 min after addition. 1 mL of DMF from a wash bottle was added, and the mixture was diluted again with 3 mL of DMF. 10 min later, 2 mL of a DMF solution containing 0.471 g (1 mmol) of the diol with an azothiazole structure was added. After reacting for 4 h, 0.0273 g (0.2 mmol) of 4-aminophenylboronic acid was added and the reaction continued for 1 h. After the reaction ended, the mixture was poured into a mold to form a film.

[0046] (3) Preparation of a sunlight-responsive high-strength self-healing polyurethane material: The polyurethane containing an azothiazole structure was dissolved in N, N-dimethylformamide, and then a methanol solution of europium trifluoromethanesulfonate was added. The mixture was stirred overnight at room temperature. The molar ratio of the azothiazole group in the polyurethane to europium trifluoromethanesulfonate was 1:0.5. After the reaction ended, the mixture was poured into a mold and the solvent was dried in an oven to obtain the sunlight-responsive high-strength self-healing polyurethane material.

[0047] Example 5

[0048] The method for preparing the diol with an azothiazole structure was the same as that in step (1) of Example 1. (2) Preparation of a polyurethane containing an azothiazole structure: At room temperature, 0.4 g (1 mmol) of water-free PEG400 was added to a 50 mL round-bottom flask. Subsequently, 2 mL of a DMF solution containing 0.4668 g (2.1 mmol) of IPDI was added. After stirring at 350 r / min at room temperature for 5 min, DBTDL was added. The viscosity increased sharply 20 min after addition. 1 mL of DMF from a wash bottle was added, and the mixture was diluted again with 3 mL of DMF. 10 min later, 2 mL of a DMF solution containing 0.471 g (1 mmol) of the diol with an azothiazole structure was added. After reacting for 4 h, 0.0273 g (0.2 mmol) of 3-aminophenylboronic acid was added and the reaction continued for 1 h. After the reaction ended, the mixture was poured into a mold to form a film.

[0049] (3) Preparation of a sunlight-responsive high-strength self-healing polyurethane material: Dissolve the polyurethane containing azothiazole structure in N, N-dimethylformamide, then add a methanol solution of iron nitrate, and stir overnight at room temperature. The molar ratio of the azothiazole group in the polyurethane to iron nitrate is 1:0.15. After the reaction, pour the mixture into a mold and dry the solvent in an oven to obtain a sunlight-responsive high-strength self-healing polyurethane material.

[0050] Example 6

[0051] The method for preparing the diol containing azothiazole structure is the same as step (1) in Example 1. (2) Preparation of polyurethane containing azothiazole structure: Add 0.4 g (1 mmol) of PEG400 free of water to a 50 mL round-bottom flask at room temperature, then add 2 mL of a DMF solution containing 0.4668 g (2.1 mmol) of HDI. Stir at 350 r / min at room temperature for 5 min, then add DBTDL. After 20 min, the viscosity increases sharply. Add 1 mL of DMF from a wash bottle and add another 3 mL of DMF for dilution. After 10 min, add 2 mL of a DMF solution containing 0.471 g (1 mmol) of the diol containing azothiazole structure. After reacting for 4 h, add 0.0273 g (0.2 mmol) of 3-aminophenylboronic acid and react for 1 h. After the reaction, pour it into a mold to form a film.

[0052] (3) Preparation of sunlight-responsive high-strength self-healing polyurethane material: Dissolve the polyurethane containing azothiazole structure in N, N-dimethylformamide, then add a methanol solution of zinc trifluoromethanesulfonate, and stir overnight at room temperature. The molar ratio of the azothiazole group in the polyurethane to zinc trifluoromethanesulfonate is 1:0.5. After the reaction, pour the mixture into a mold and dry the solvent in an oven to obtain a sunlight-responsive high-strength self-healing polyurethane material.

[0053] Example 7

[0054] The method for preparing the diol containing azothiazole structure is the same as step (1) in Example 1. (2) Preparation of polyurethane containing azothiazole structure: At room temperature, 1 g (2.5 mmol) of water-free PEG400 was added to a 50 mL round-bottom flask, and then 2 mL of a DMF solution containing 0.855 g (2.1 mmol) of MDI was added. After stirring at 350 r / min at room temperature for 5 min, DBTDL was added. The viscosity increased sharply 20 min after the addition. 1 mL of DMF from a wash bottle was added, and then 3 mL of DMF was added again for dilution. 10 min later, 2 mL of a DMF solution containing 0.3925 g (0.83 mmol) of a diol with an azothiazole structure was added. After reacting for 4 h, 0.0228 g (0.16 mmol) of 4-aminophenylboronic acid was added and the reaction continued for 1 h. After the reaction was completed, the mixture was poured into a mold to form a film.

[0055] (3) Preparation of a sunlight-responsive high-strength self-healing polyurethane material: The polyurethane containing an azothiazole structure was dissolved in N,N-dimethylformamide, and then a methanol solution of zinc trifluoromethanesulfonate was added. The mixture was stirred overnight at room temperature. The molar ratio of the azothiazole group in the polyurethane to zinc trifluoromethanesulfonate was 1:0.5. After the reaction was completed, the mixture was poured into a mold and the solvent was dried in an oven to obtain a sunlight-responsive high-strength self-healing polyurethane material.

[0056] In summary, by introducing a photoactive azobenzothiazole structure into the polyurethane, the present invention realizes the sunlight-responsive self-healing of a high-strength polyurethane material through reversible metal coordination bonds responsive to sunlight, solving the problem that existing photo-responsive self-healing materials require irradiation with light of a specific wavelength.

[0057] The above are only preferred embodiments of the present invention and do not impose any form of limitation on the present invention. Although the present invention has been disclosed above with preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some changes or modifications to the above-disclosed technical content to obtain equivalent embodiments with equivalent changes within the scope of the technical solution of the present invention. However, any simple modification, equivalent change, and modification made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A sunlight-responsive high-strength self-healing polyurethane material, characterized in that, The polyurethane material is obtained by coordinating polyurethane containing an azothiazole structure with metal ions. The molar ratio of the azothiazole structure to the metal ions in the polyurethane containing an azothiazole structure is 1:0.15 - 0.

5. The polyurethane containing an azothiazole structure is obtained by reacting a diisocyanate, a diol containing an azothiazole structure, a long-chain diol, and aminophenylboronic acid in a molar ratio of 1:0.5 - 0.8:0.2 - 0.5:0.03 - 0.

15. The general structural formula of the polyurethane is as follows: ； In the formula, the value range of m is 1 - 6, and the value range of n is 3 - 40; In the formula, R1 is one or more of the following structural formulas; ； In the formula, R2 is one or more of the following structural formulas; ； In the formula, the value range of x is 1 - 30.

2. The sunlight-responsive high-strength self-healing polyurethane material according to claim 1, characterized in that The metal ions are selected from one or more of ferric trichloride, zinc chloride, copper chloride, ferric nitrate, zinc nitrate, copper nitrate, terbium trifluoromethanesulfonate, zinc trifluoromethanesulfonate, and europium trifluoromethanesulfonate.

3. The sunlight-responsive high-strength self-healing polyurethane material according to claim 1, characterized in that The aminophenylboronic acid is one or more of 2-aminophenylboronic acid, 3-aminophenylboronic acid, and 4-aminophenylboronic acid.

4. The sunlight-responsive high-strength self-healing polyurethane material according to claim 1, wherein The general structural formula of the diol containing an azothiazole structure is as follows: ； In the formula, the value range of m is 1 - 6.

5. The preparation method of a sunlight-responsive high-strength self-healing polyurethane material according to any one of claims 1 to 4, characterized in that, It includes the following steps: S1. Preparation of the diol containing an azothiazole structure: Add a diphenol containing an azothiazole structure, a chloro-substituted alkyl alcohol, potassium carbonate, and potassium iodide into a round-bottom flask in a molar ratio of 1:2.2:2.4:0.4, dissolve with N, N-dimethylformamide, and stir and react at 80 °C for 10 hours; after the reaction is completed, the diol containing an azothiazole structure is obtained through extraction, washing, and drying. S2. Preparation of the polyurethane containing an azothiazole structure: Under nitrogen protection, dissolve the diisocyanate, the diol containing an azothiazole structure, and the long-chain diol with N, N-dimethylformamide, add the catalyst dibutyltin dilaurate, react at room temperature for 3 - 4 hours, add aminophenylboronic acid and continue to react for 1 - 2 hours to obtain the polyurethane containing an azothiazole structure; the molar ratio of the diisocyanate, the diol containing an azothiazole structure, the long-chain diol, and aminophenylboronic acid is 1:0.5 - 0.8:0.2 - 0.5:0.03 - 0.

15. S3. Preparation of the sunlight-responsive high-strength self-healing polyurethane material: Dissolve the polyurethane containing an azothiazole structure in tetrahydrofuran, then add a methanol solution of a metal salt, and stir overnight at room temperature; the molar ratio of the azothiazole group to the metal ions in the polyurethane is 1:0.15 - 0.5; after the reaction is completed, pour the mixed solution into a mold and dry the solvent in an oven to obtain the sunlight-responsive high-strength self-healing polyurethane material.

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