Sunlight-driven rapid self-repairing high-toughness polyurethane as well as preparation method and application thereof

Abstract

The invention provides sunlight-driven rapid self-repairing high-toughness polyurethane as well as a preparation method and application thereof, and relates to the technical field of ecological polymer materials. According to the sunlight-driven rapid self-repairing high-toughness polyurethane provided by the invention, diisocyanate, a chain extender, an organic solvent, a catalyst, dimethylglyoxime and heterojunction nanocrystals are taken as preparation raw materials, wherein the heterojunction nanocrystals comprise one or more of TiO2-CuS, CuO-CuS, TiO2-CuO and ZnS-CuS. Specific heterojunction nanocrystals are selected, the light absorption range of self-repairing polyurethane is widened, the light absorption efficiency is enhanced, excellent antibacterial performance is given, and efficient self-repairing of damage under driving of natural light such as sunlight is achieved in combination with a specific dynamic structure of self-repairing polyurethane. Meanwhile, the heterojunction nanocrystals and oxime bonds generate a coordination effect, so that the polyurethane material has the mechanical properties of high strength, high toughness and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of ecological polymer materials, and in particular to a high-strength and tough polyurethane with rapid self-repairing properties driven by sunlight, and a preparation method and application thereof. Background Art

[0002] Self-healing polyurethane materials are a key research area in materials science. Their ability to mimic the self-repairing properties of living organisms offers significant advantages in extending material lifespan and reducing maintenance costs. However, research into self-healing polyurethane materials remains plagued by key bottlenecks: First, most self-healing polyurethanes rely on artificial excitation conditions (such as heating or exposure to ultraviolet or near-infrared light of a specific wavelength) to trigger the repair process, resulting in limited repair efficiency and restricting their application in natural environments such as sunlight or in unmanned environments. Second, it is difficult to balance mechanical properties with self-healing performance. In recent years, light-driven self-healing materials have attracted attention due to their high controllability and low energy consumption. Traditional photoresponsive systems typically rely on single-component photothermal agents (such as carbon-based materials or precious metal nanoparticles) or photosensitizing groups, which have a narrow light absorption range (concentrated in the ultraviolet or near-infrared bands) and significantly limit their repair efficiency due to illumination conditions. Furthermore, the photoresponsiveness of such materials is not compatible with the substrate, which can lead to a decrease in mechanical properties. This makes it difficult to achieve both high strength and toughness and high self-healing efficiency, hindering practical applications. Therefore, it is of great significance to study self-healing polyurethane materials that have both high strength and toughness and high self-healing efficiency. Summary of the Invention

[0003] In view of this, the object of the present invention is to provide a high-strength and tough polyurethane with rapid self-repairing properties driven by sunlight, as well as a preparation method and application thereof. The high-strength and tough polyurethane with rapid self-repairing properties driven by sunlight provided by the present invention has both excellent mechanical properties and self-repairing capabilities.

[0004] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0005] The present invention provides a high-strength and tough polyurethane with rapid self-repairing properties driven by sunlight. The polyurethane comprises the following raw materials in parts by weight: 7 to 16 parts of diisocyanate, 20 to 40 parts of a chain extender, 23 to 46 parts of an organic solvent, 0.06 to 0.2 parts of a catalyst, 2.9 to 6 parts of dimethylglyoxime, and 0.02 to 1 parts of heterojunction nanocrystals; the chain extender comprises one or more of a polyether chain extender and a polyester chain extender; and the heterojunction nanocrystals comprise one or more of TiO2-CuS, CuO-CuS, TiO2-CuO, and ZnS-CuS.

[0006] Preferably, the diisocyanate includes one or more of isophorone diisocyanate, diphenylmethane diisocyanate, toluene diisocyanate, 4,4'-dicyclohexylmethane diisocyanate and hexamethylene diisocyanate.

[0007] Preferably, the chain extender includes one or more of polytetramethylene glycol, polypropylene glycol, polycaprolactone glycol, polyethylene glycol and polycarbonate glycol.

[0008] Preferably, the mass content of TiO2 in the TiO2-CuS is 20-60%;

[0009] The mass content of CuO in the CuO-CuS is 20-60%;

[0010] The mass content of TiO2 in the TiO2-CuO is 10-50%;

[0011] The mass content of ZnS in the ZnS-CuS is 30-60%;

[0012] The particle size of the heterojunction nanocrystal is 20-50 nm.

[0013] Preferably, the organic solvent includes one or more of an amide organic solvent, a ketone organic solvent and an ether organic solvent;

[0014] The catalyst includes one or more of dibutyltin dilaurate, stannous octoate, dibutyltin diacetate and dibutyltin didodecylsulfide.

[0015] The present invention also provides a method for preparing the high-toughness polyurethane with rapid self-repairing properties driven by sunlight as described in the above technical solution, comprising the following steps:

[0016] Mixing diisocyanate, chain extender, organic solvent and catalyst to carry out polymerization reaction to obtain polyurethane prepolymer;

[0017] The polyurethane prepolymer is subjected to an addition reaction with dimethylglyoxime to obtain a self-repairing polyurethane;

[0018] The self-repairing polyurethane is compounded with heterojunction nanocrystals to obtain the high-strength and tough polyurethane that is driven by sunlight and can quickly self-repair.

[0019] Preferably, the polymerization reaction temperature is 60-90° C., and the time is 0.5-5 h.

[0020] Preferably, the temperature of the addition reaction is 60-90° C., and the time is 3-5 hours.

[0021] Preferably, the compounding temperature is 60-90° C. and the compounding time is 6-14 hours.

[0022] The present invention also provides the use of the high-toughness polyurethane with rapid self-repairing driven by sunlight as described in the above technical solution or the high-toughness polyurethane with rapid self-repairing driven by sunlight as prepared by the preparation method described in the above technical solution in solar self-repairing materials.

[0023] The present invention uses specific heterojunction nanocrystals to form a built-in electric field at the heterojunction interface, promotes the separation of photogenerated electron-hole pairs, broadens the light absorption range, enhances the light absorption efficiency, and realizes efficient self-repair of damage driven by natural light such as sunlight. The oxime bond (C=N-OH) formed by the diacetyl oxime added in the present invention can produce a coordination effect with the metal ions of the heterojunction nanocrystal, enhance the cross-linking density of the material, and improve the mechanical properties of the high-toughness polyurethane that can quickly self-repair driven by sunlight, so as to achieve efficient self-repair under sunlight excitation while having both high strength and high toughness, which can solve the problem that the light absorption range is narrow in the current light-responsive materials and the mechanical properties and self-repair efficiency cannot be achieved at the same time. In addition, the heterojunction nanocrystals produce a coordination effect with the oxime bond, ensuring that the material has both efficient self-repair efficiency and antibacterial properties under the premise of excellent mechanical properties.

[0024] As shown in the test results of the embodiment, the tensile strength of the solar-driven rapid self-repairing high-toughness polyurethane provided by the present invention is above 25.27 MPa, the elongation at break is above 1458%, and the toughness is above 220.6 MJ / m 3 As shown above, the single repair efficiency is above 95.5%; after three self-repairs, the tensile strength of the high-toughness polyurethane driven by sunlight and quickly self-repaired prepared in Example 1 is still maintained at 95.5%, the elongation at break is still maintained at 91.9%, and the toughness is still maintained at 86.2%; the high-toughness polyurethane driven by sunlight and quickly self-repaired can achieve sunlight-driven rapid self-repair 30 minutes after fracture; the antibacterial rate of the high-toughness polyurethane driven by sunlight and quickly self-repaired against Escherichia coli and Staphylococcus aureus is more than 99%. This shows that the high-toughness polyurethane driven by sunlight and quickly self-repaired provided by the present invention has excellent strength, toughness and sunlight-driven rapid self-repair performance, and has a high repair rate, and also has excellent antibacterial properties. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 The infrared spectra of the self-healing polyurethane (PUO) prepared in Example 1 and the high-strength and tough polyurethane (PUO-TiO2 / CuS) driven by sunlight for rapid self-healing;

[0026] Figure 2 Light absorption graphs of self-healing polyurethane (PUO), heterojunction nanocrystalline TiO2-CuS, and sunlight-driven fast self-healing high-toughness polyurethane (PUO-TiO2 / CuS) prepared in Example 1;

[0027] Figure 3 The photos of the sunlight-stimulated self-healing polyurethane prepared in Example 1 before and after crack repair, where 1) is before self-repair and 2) is after self-repair;

[0028] Figure 4 This is a graph showing the antibacterial test results of the sunlight-driven fast self-repairing high-toughness polyurethane prepared in Example 1 against Escherichia coli and Staphylococcus aureus. DETAILED DESCRIPTION

[0029] The present invention provides a high-strength and tough polyurethane with rapid self-repairing properties driven by sunlight. The polyurethane comprises the following raw materials in parts by weight: 7 to 16 parts of diisocyanate, 20 to 40 parts of a chain extender, 23 to 46 parts of an organic solvent, 0.06 to 0.2 parts of a catalyst, 2.9 to 6 parts of dimethylglyoxime, and 0.02 to 1 parts of heterojunction nanocrystals; the chain extender comprises one or more of a polyether chain extender and a polyester chain extender; and the heterojunction nanocrystals comprise one or more of TiO2-CuS, CuO-CuS, TiO2-CuO, and ZnS-CuS.

[0030] Unless otherwise specified, the materials and equipment used in the present invention are all commercially available products in the art.

[0031] The raw materials for preparing the sunlight-driven, fast-self-repairing, high-toughness polyurethane provided by the present invention include 7 to 16 parts by mass of diisocyanate, preferably 7.78 to 15.56 parts, and specifically 7 parts, 7.78 parts, 8 parts, 9 parts, 10 parts, 11 parts, 12 parts, 13 parts, 14 parts, 15 parts, 15.56 parts, or 16 parts. In the present invention, the diisocyanate preferably includes one or more of isophorone diisocyanate, diphenylmethane diisocyanate, toluene diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, and hexamethylene diisocyanate.

[0032] The raw materials for preparing the sunlight-driven rapid self-repairing high-toughness polyurethane provided by the present invention include 20 to 40 parts of a chain extender, specifically 20 parts, 22 parts, 25 parts, 28 parts, 30 parts, 32 parts, 35 parts, 38 parts or 40 parts, based on the mass fraction of the diisocyanate. In the present invention, the chain extender includes one or more of a polyether chain extender and a polyester chain extender, preferably including one or more of polytetramethylene ether glycol (PTMEG), polypropylene glycol (PPG), polycaprolactone glycol (PCL), polyethylene glycol and polycarbonate diol.

[0033] The raw materials for preparing the sunlight-driven, fast-self-repairing, high-toughness polyurethane provided by the present invention include 23 to 46 parts of an organic solvent, specifically 23 parts, 25 parts, 28 parts, 30 parts, 32 parts, 35 parts, 38 parts, 40 parts, 42 parts, 44 parts, or 46 parts, based on the mass of the diisocyanate. In the present invention, the organic solvent preferably includes one or more of an amide organic solvent, a ketone organic solvent, and an ether organic solvent, and more preferably includes one or more of N,N-dimethylformamide, acetone, and tetrahydrofuran.

[0034] The raw materials for preparing the sunlight-driven rapid self-repairing high-toughness polyurethane provided by the present invention include 0.06 to 0.2 parts of a catalyst, specifically 0.06 parts, 0.08 parts, 0.1 parts, 0.12 parts, 0.14 parts, 0.142 parts, 0.146 parts, 0.15 parts, 0.16 parts, 0.18 parts or 0.2 parts, based on the mass fraction of the diisocyanate. In the present invention, the catalyst preferably includes one or more of dibutyltin dilaurate, stannous octoate, dibutyltin diacetate and di(dodecylsulfide)dibutyltin.

[0035] The raw materials for preparing the high-toughness polyurethane driven by sunlight for rapid self-repair provided by the present invention include 2.9 to 6 parts of dimethylglyoxime, which can be specifically 2.9 parts, 3 parts, 3.2 parts, 3.5 parts, 3.8 parts, 4 parts, 4.2 parts, 4.5 parts, 4.8 parts, 5 parts, 5.2 parts, 5.5 parts, 5.8 parts or 6 parts, based on the mass fraction of the diisocyanate. The oxime bond (C=N-OH) formed by the dimethylglyoxime added in the present invention can produce a coordination effect with the metal ions of the heterojunction nanocrystals, enhance the crosslinking density of the material, and improve the mechanical properties of the high-toughness polyurethane driven by sunlight for rapid self-repair, so as to achieve high strength and high toughness while having high efficiency of self-repair.

[0036] The raw materials for preparing the sunlight-driven fast self-repairing high-toughness polyurethane provided by the present invention include 0.02 to 1 parts of heterojunction nanocrystals, specifically 0.02 parts, 0.05 parts, 0.08 parts, 0.1 parts, 0.2 parts, 0.3 parts, 0.4 parts, 0.5 parts, 0.6 parts, 0.7 parts, 0.8 parts, 0.9 parts or 1 parts, based on the mass fraction of the diisocyanate. In the present invention, the heterojunction nanocrystals include one or more of TiO2-CuS, CuO-CuS, TiO2-CuO and ZnS-CuS. In the present invention, the mass content of TiO2 in the TiO2-CuS is preferably 20 to 60%, specifically 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55% or 60%. In the present invention, the mass content of CuO in the CuO-CuS is preferably 20-60%, and can be specifically 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55% or 60%. In the present invention, the mass content of TiO2 in the TiO2-CuO is preferably 10-50%, and can be specifically 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45% or 50%. In the present invention, the mass content of ZnS in the ZnS-CuS is 30-60%, and can be specifically 30%, 35%, 40%, 45%, 50%, 55% or 60%. In the present invention, the particle size of the heterojunction nanocrystal is preferably 20-50nm, and can be specifically 20nm, 25nm, 27nm, 28nm, 30nm, 35nm, 40nm, 45nm or 50nm. The present invention utilizes specific heterojunction nanocrystals to broaden the light absorption range of the self-healing polyurethane, enhancing its light absorption efficiency and imparting excellent antibacterial properties. Combined with the self-healing polyurethane's unique dynamic structure, it achieves efficient self-repair of damage driven by sunlight and other natural light. Furthermore, the coordination between the heterojunction nanocrystals and oxime bonds imparts to the polyurethane material a combination of high strength and toughness.

[0037] In the present invention, the preparation method of TiO2-CuS preferably includes the following steps: mixing TiO2, copper salt, Na2S and water, and performing a hydrothermal reaction to obtain TiO2-CuS.

[0038] In the present invention, the mixing is preferably: ultrasonically mixing TiO2 and a copper salt aqueous solution, and stirring the resulting mixture with a Na2S aqueous solution.

[0039] In the present invention, the copper salt preferably includes one or both of Cu(NO3)2 and CuSO4; the concentration of the copper salt aqueous solution is preferably 0.4 to 0.6 mol / L, specifically 0.4 mol / L, 0.45 mol / L, 0.5 mol / L, 0.55 mol / L, or 0.6 mol / L. The mass ratio of the TiO2 to the copper salt is not particularly limited, as long as the mass content of TiO2 in the TiO2-CuS is 20 to 60%.

[0040] In the present invention, the temperature of the ultrasonic mixing is preferably room temperature (18-30°C); the power of the ultrasonic mixing is preferably 400-600W, and can be specifically 400W, 450W, 500W, 550W or 600W; the time of the ultrasonic mixing is preferably 20-40min, and can be specifically 20min, 25min, 30min, 35min or 40min.

[0041] In the present invention, the concentration of the Na2S aqueous solution is preferably 0.4 to 0.6 mol / L, specifically 0.4 mol / L, 0.45 mol / L, 0.5 mol / L, 0.55 mol / L or 0.6 mol / L. In the present invention, the molar ratio of copper to Na2S in the copper salt is preferably 1:1 to 6, specifically 1:1, 1:2, 1:3, 1:4, 1:5 or 1:6.

[0042] In the present invention, the stirring and mixing temperature is preferably room temperature (18-30° C.); the stirring and mixing time is preferably 0.5-2 h, specifically 0.5 h, 1 h, 1.5 h or 2 h.

[0043] In the present invention, the temperature of the hydrothermal reaction is preferably 170-180°C, specifically 170°C, 172°C, 175°C, 178°C or 180°C; the time of the hydrothermal reaction is preferably 13-16h, specifically 13h, 14h, 15h or 16h.

[0044] After completing the hydrothermal reaction, the present invention preferably further comprises: subjecting the reaction solution obtained by the hydrothermal reaction to solid-liquid separation, washing the obtained solid component and then drying it to obtain TiO2-CuS. The present invention has no special limitation on the solid-liquid separation, and can adopt a solid-liquid separation method well known to those skilled in the art, such as filtration, suction filtration or centrifugal separation. In the present invention, the washing preferably includes one or both of water washing and anhydrous ethanol washing; the water used for washing preferably includes distilled water, deionized water or ultrapure water. In the present invention, the drying temperature is preferably 50 to 80°C, and can be specifically 50°C, 60°C, 70°C or 80°C; the present invention has no special limitation on the drying time, and can be dried to constant weight.

[0045] In the present invention, the difference between the preparation method of CuO-CuS and the preparation method of TiO2-CuS is that TiO2 is replaced by CuO, and the preparation method of CuO-CuS is not described in detail here.

[0046] In the present invention, the difference between the preparation method of TiO2-CuO and the preparation method of TiO2-CuS is only that: Na2S is replaced by alkali metal hydroxide, and the alkali metal hydroxide preferably includes at least one of NaOH and KOH; the amount of the alkali metal hydroxide is based on adjusting the pH value of the system to 11-12 (specifically 11, 11.2, 11.5, 11.8 or 12). The preparation method of TiO2-CuO is not described in detail here.

[0047] In the present invention, the difference between the preparation method of ZnS-CuS and the preparation method of TiO2-CuS is that TiO2 is replaced by ZnS, and the preparation method of ZnS-CuS is not described in detail here.

[0048] The present invention also provides a method for preparing the high-toughness polyurethane with rapid self-repairing properties driven by sunlight as described in the above technical solution, comprising the following steps:

[0049] Mixing diisocyanate, chain extender, organic solvent and catalyst to carry out polymerization reaction to obtain polyurethane prepolymer;

[0050] The polyurethane prepolymer is subjected to an addition reaction with dimethylglyoxime to obtain a self-repairing polyurethane;

[0051] The self-repairing polyurethane is compounded with heterojunction nanocrystals to obtain the high-strength and tough polyurethane that is driven by sunlight and can quickly self-repair.

[0052] The present invention mixes a diisocyanate, a chain extender, an organic solvent, and a catalyst, and conducts a polymerization reaction to obtain a polyurethane prepolymer. In the present invention, the mixing is preferably performed by premixing the diisocyanate, chain extender, and organic solvent, and then adding the catalyst and mixing. In the present invention, the mixing temperature is preferably 60-90°C, specifically 60°C, 65°C, 70°C, 75°C, 80°C, 85°C, or 90°C; the premixing time is preferably 0.5-1.5 hours, specifically 0.5 hours, 1 hour, or 1.5 hours. In the present invention, the polymerization reaction temperature is preferably 60-90°C, specifically 60°C, 65°C, 70°C, 75°C, 80°C, 85°C, or 90°C; the polymerization reaction time is preferably 0.5-5 hours, more preferably 3-5 hours, specifically 0.5 hours, 1 hour, 2 hours, 3 hours, 4 hours, or 5 hours; and the polymerization reaction is preferably carried out under stirring conditions.

[0053] After obtaining the polyurethane prepolymer, the present invention performs an addition reaction on the polyurethane prepolymer and dimethylglyoxime to obtain a self-healing polyurethane. In the present invention, the temperature of the addition reaction is preferably 60 to 90°C, specifically 60°C, 65°C, 70°C, 75°C, 80°C, 85°C, or 90°C; the time of the addition reaction is preferably 3 to 5 hours, specifically 3 hours, 3.5 hours, 4 hours, 4.5 hours, or 5 hours; and the addition reaction is preferably carried out under stirring conditions.

[0054] After obtaining the self-healing polyurethane, the present invention composites the self-healing high-toughness polyurethane with heterojunction nanocrystals to obtain the sunlight-driven rapid self-healing high-toughness polyurethane. In the present invention, the composite temperature is preferably 60 to 90°C, specifically 60°C, 65°C, 70°C, 75°C, 80°C, 85°C, or 90°C; the composite time is preferably 6 to 14 hours, specifically 6 hours, 7 hours, 8 hours, 9 hours, 10 hours, 11 hours, 12 hours, 13 hours, or 14 hours; the composite is preferably blended, and the composite is preferably carried out under stirring conditions.

[0055] The present invention also provides the use of the high-toughness polyurethane with rapid self-repairing driven by sunlight as described in the above technical solution or the high-toughness polyurethane with rapid self-repairing driven by sunlight as prepared by the preparation method described in the above technical solution in solar self-repairing materials.

[0056] The present invention uses specific heterojunction nanocrystals to form a built-in electric field at the heterojunction interface, promotes the separation of photogenerated electron-hole pairs, broadens the light absorption range, enhances the light absorption efficiency, and realizes efficient self-repair of damage driven by natural light such as sunlight. The oxime bond (C=N-OH) formed by the dimethylglyoxime added in the present invention can produce a coordination effect with the metal ions of the heterojunction nanocrystals, enhance the cross-linking density of the material, and improve the mechanical properties of the high-strength and tough polyurethane with rapid self-repair driven by sunlight, so as to achieve high-efficiency self-repair under the premise of high-strength and high toughness under the excitation of sunlight, and solve the problem that the light absorption range is narrow and the mechanical properties and self-repair efficiency cannot be achieved at the same time in the current light-responsive materials. In addition, the heterojunction nanocrystals added in the present invention also have antibacterial ions, which can interfere with the activity of bacterial metabolic enzymes and destroy cell membranes, giving the high-strength and tough polyurethane with rapid self-repair driven by sunlight excellent antibacterial properties. The high-strength and tough polyurethane with rapid self-repair driven by sunlight provided by the present invention has a good application prospect in solar self-repairing materials.

[0057] To further illustrate the present invention, the sunlight-driven rapid self-repairing high-toughness polyurethane provided by the present invention, its preparation method and application are described in detail below in conjunction with the examples, but they should not be understood as limiting the scope of protection of the present invention.

[0058] Example 1

[0059] Synthesis of heterojunction nanocrystalline TiO2-CuS: 0.6 g TiO2 was ultrasonically mixed with 25 mL of 0.5 mol / L Cu(NO3)2 aqueous solution at room temperature and 400 W for 30 min, followed by addition of 25 mL of 0.5 mol / L Na2S aqueous solution, stirred for 1 h, and hydrothermally reacted at 180 ° C for 14 h. The mixture was filtered, washed with anhydrous ethanol, and dried at 80 ° C for 5 h to obtain TiO2-CuS with a particle size of 27 nm.

[0060] Preparation of high-strength and tough polyurethane with rapid self-repair driven by sunlight: Add 20g of polytetramethylene ether glycol (PTMEG), 7.78g of isophorone diisocyanate and 20mL of N,N-dimethylformamide, mix at 60°C for 1h, then add 0.08g of dibutyltin dilaurate, keep the temperature constant and continue stirring and reacting for 4h to obtain a polyurethane prepolymer. Add 2.9g of dimethylglyoxime to the above polyurethane prepolymer and react at 60°C for 4h to obtain a self-repairing polyurethane (denoted as PUO). Add 0.2g of TiO2-CuS (or denoted as TiO2 / CuS) to the above self-repairing high-strength and tough polyurethane and stir at 60°C for 6h to obtain a high-strength and tough polyurethane with rapid self-repair driven by sunlight (denoted as PUO-TiO2 / CuS).

[0061] Figure 1 The infrared spectra of PUO and PUO-TiO2 / CuS prepared in Example 1 show that the isocyanate groups in the raw materials have completely reacted with the hydroxyl groups to generate carbamate groups and form oxime carbamate bonds and metal coordination bonds.

[0062] The absorbance of PUO, TiO2-CuS and PUO-TiO2 / CuS prepared in Example 1 was detected by UV-spectrophotometer. Figure 2 As shown, it is shown that the heterojunction nanocrystals of high-strength and tough polyurethane with rapid self-repair driven by sunlight and the high-strength and tough self-repairing polyurethane both have absorption in the range of 200 to 2500 nm.

[0063] Example 2

[0064] Synthesis of heterojunction nanocrystalline CuO-CuS: 0.6 g of CuO was ultrasonically mixed with 25 mL of 0.5 mol / L Cu(NO3)2 aqueous solution at room temperature and 600 W for 30 min, followed by the addition of 25 mL of 0.5 mol / L Na2S aqueous solution, stirred for 1 h, and hydrothermally reacted at 180 ° C for 14 h. The mixture was filtered, washed with anhydrous ethanol, and dried at 80 ° C for 5 h to obtain CuO-CuS with a particle size of 28 nm.

[0065] Preparation of a high-strength, sunlight-driven, fast-self-healing polyurethane: 40g of polytetramethylene ether glycol (PTMEG), 15.56g of 4,4'-dicyclohexylmethane diisocyanate, and 40mL of tetrahydrofuran were added and mixed at 90°C for 1 hour. Then, 0.14g of dibutyltin dilaurate was added and the mixture was stirred at the same temperature for 4 hours to obtain a polyurethane prepolymer. 6g of dimethylglyoxime was added to the prepolymer and the mixture was reacted at 60°C for 4 hours to obtain a self-healing polyurethane. 0.4g of CuO-CuS was added to the self-healing polyurethane and stirred at 60°C for 6 hours to obtain a high-strength, sunlight-driven, fast-self-healing polyurethane.

[0066] Example 3

[0067] Synthesis of heterojunction nanocrystalline TiO2-CuO: 0.6 g TiO2 was ultrasonically mixed with 25 mL of 0.5 mol / L Cu(NO3)2 aqueous solution at room temperature and 400 W for 30 min, and then 0.5 mol / L NaOH aqueous solution was added and stirred for 1 h to obtain a mixture with a pH value of 12. The mixture was hydrothermally reacted at 180°C for 14 h, filtered, washed with ultrapure water and anhydrous ethanol, and dried at 80°C for 5 h to obtain TiO2-CuO with a particle size of 28 nm.

[0068] Preparation of high-strength and tough polyurethane with rapid self-repair driven by sunlight: 40g of polypropylene glycol (PPG), 15.56g of diphenylmethane diisocyanate and 40mL of acetone were mixed at 90°C for 1h, followed by the addition of 0.146g of dibutyltin dilaurate and the reaction was stirred at the same temperature for 4h to obtain a polyurethane prepolymer. 6g of dimethylglyoxime was added to the above polyurethane prepolymer and the mixture was reacted at 60°C for 4h to obtain a self-repairing polyurethane. 0.8g of TiO2-CuO was added to the above self-repairing high-strength and tough polyurethane and stirred at 60°C for 6h to obtain a high-strength and tough polyurethane with rapid self-repair driven by sunlight.

[0069] Example 4

[0070] Synthesis of heterojunction nanocrystalline ZnS-CuS: 0.6 g ZnS was ultrasonically mixed with 25 mL of 0.5 mol / L Cu(NO3)2 aqueous solution at room temperature and 500 W for 30 min, followed by the addition of 25 mL of 0.5 mol / L Na2S aqueous solution, stirred for 1 h, and hydrothermally reacted at 180 ° C for 14 h. The mixture was filtered, washed with ultrapure water, and dried at 80 ° C for 5 h to obtain ZnS-CuS with a particle size of 30 nm.

[0071] Preparation of high-strength and tough polyurethane with rapid self-repair driven by sunlight: 40g of polycaprolactone diol (PCL), 15.56g of hexamethylene diisocyanate, and 40mL of tetrahydrofuran were mixed at 70°C for 1h, followed by the addition of 0.142g of dibutyltin dilaurate and the reaction was stirred at the same temperature for 4h to obtain a polyurethane prepolymer. 6g of dimethylglyoxime was added to the above polyurethane prepolymer and the mixture was reacted at 60°C for 4h to obtain a self-repairing polyurethane. 0.8g of ZnS-CuS was added to the above self-repairing high-strength and tough polyurethane and stirred at 60°C for 6h to obtain a high-strength and tough polyurethane with rapid self-repair driven by sunlight.

[0072] Test Example 1

[0073] According to GB / T 528-2009, dumbbell-shaped standard specimens of the sunlight-driven rapid self-repairing high-toughness polyurethane prepared in Examples 1 to 4 were prepared to perform mechanical property and self-repair tests.

[0074] Self-repair test: Cut the dumbbell-shaped standard specimen from the middle to a thickness of 0.5 mm, then join the sections together and test the tensile strength of the material after irradiating it under sunlight for 30 minutes. Repeat the cutting and repairing, and the repair rate is defined as the tensile strength of the repaired specimen (σ healed ) and the tensile strength of the original specimen (σ original ) ratio, the repair rate calculation formula is η=(σ healed / σ original )×100%, and the test results are shown in Tables 1 and 2.

[0075] The scratch repair evaluation material repair time stimulated by sunlight is used, such as Figure 3 As shown in the figure, 1) is the original sample with a crack depth of 0.5 mm, and 2) is the sample after 30 minutes of self-repair.

[0076] Table 1 Mechanical properties and multiple repair test results of the high-toughness polyurethane driven by sunlight for rapid self-repair prepared in Example 1

[0077] Example 1 Tensile strength (MPa) Elongation at break (%) <![CDATA[Toughness (MJ / m 3 )]]> Repair rate (%) Original Materials 28.43 1775 261.7 / Materials after self-repair 1 time 28.03 1727 244.2 98.6 Materials after self-repair 2 times 27.52 1667 232.4 96.8 Material after self-repair 3 times 27.15 1631 225.5 95.5

[0078] Table 2 Mechanical properties and single repair test results of high-toughness polyurethane driven by sunlight for rapid self-repair in the examples of this application

[0079] Examples Tensile strength (MPa) Elongation at break (%) <![CDATA[Toughness (MJ / m 3 )]]> Single repair rate (%) Example 2 28.25 1720 255.4 98.3 Example 3 25.27 1458 220.6 97.6 Example 4 30.16 1548 247.6 96.2

[0080] From Tables 1 to 2 and Figure 3It can be seen that the tensile strength of the high-toughness polyurethane with rapid self-repair driven by sunlight provided by the present invention is above 25.27MPa, the elongation at break is above 1458%, the toughness is above 220.6MJ / m3, and the single repair efficiency is above 95.5%; after three self-repairs, the tensile strength of the high-toughness polyurethane with rapid self-repair driven by sunlight prepared in Example 1 is still maintained at 95.5%, the elongation at break is still maintained at 91.9%, and the toughness is still maintained at 86.2%; the high-toughness polyurethane with rapid self-repair driven by sunlight can achieve rapid self-repair driven by sunlight 30 minutes after fracture. This shows that the high-toughness polyurethane with rapid self-repair driven by sunlight provided by the present invention has excellent strength, toughness and rapid self-repairing performance driven by sunlight, and has a high repair rate.

[0081] The antibacterial properties of the solar-driven rapid self-repairing high-strength polyurethane prepared in Example 1 were tested using Staphylococcus aureus (S. aureus., ATCC29213) and Escherichia coli (E. coli., ATCC25922). Figure 4 As shown, the antibacterial rate of the sunlight-driven fast self-repairing high-toughness polyurethane prepared by the present invention against Escherichia coli and Staphylococcus aureus reached more than 99%, and the antibacterial activity was excellent.

[0082] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A sunlight-driven, fast-self-repairing, high-strength polyurethane comprising the following raw materials in parts by weight: 7 to 16 parts of diisocyanate, 20 to 40 parts of a chain extender, 23 to 46 parts of an organic solvent, 0.06 to 0.2 parts of a catalyst, 2.9 to 6 parts of dimethylglyoxime, and 0.02 to 1 part of heterojunction nanocrystals; the chain extender comprising one or more of a polyether chain extender and a polyester chain extender; and the heterojunction nanocrystals comprising one or more of TiO2-CuS, CuO-CuS, TiO2-CuO, and ZnS-CuS.

2. The sunlight-driven rapid self-repairing high-toughness polyurethane according to claim 1, characterized in that: The diisocyanate includes one or more of isophorone diisocyanate, diphenylmethane diisocyanate, toluene diisocyanate, 4,4'-dicyclohexylmethane diisocyanate and hexamethylene diisocyanate.

3. The sunlight-driven rapid self-repairing high-toughness polyurethane according to claim 1, characterized in that: The chain extender includes one or more of polytetramethylene glycol, polypropylene glycol, polycaprolactone glycol, polyethylene glycol and polycarbonate glycol.

4. The sunlight-driven rapid self-repairing high-toughness polyurethane according to claim 1, characterized in that: The mass content of TiO2 in the TiO2-CuS is 20-60%; The mass content of CuO in the CuO-CuS is 20-60%; The mass content of TiO2 in the TiO2-CuO is 10-50%; The mass content of ZnS in the ZnS-CuS is 30-60%; The particle size of the heterojunction nanocrystal is 20-50 nm.

5. The sunlight-driven rapid self-repairing high-toughness polyurethane according to claim 1, characterized in that: The organic solvent includes one or more of an amide organic solvent, a ketone organic solvent and an ether organic solvent; The catalyst includes one or more of dibutyltin dilaurate, stannous octoate, dibutyltin diacetate and dibutyltin didodecylsulfide.

6. The method for preparing the sunlight-driven rapid self-repairing high-toughness polyurethane according to any one of claims 1 to 5, comprising the following steps: Mixing diisocyanate, chain extender, organic solvent and catalyst to carry out polymerization reaction to obtain polyurethane prepolymer; The polyurethane prepolymer is subjected to an addition reaction with dimethylglyoxime to obtain a self-repairing polyurethane; The self-repairing polyurethane is compounded with heterojunction nanocrystals to obtain the high-strength and tough polyurethane that is driven by sunlight and can quickly self-repair.

7. The preparation method according to claim 6, characterized in that The polymerization reaction temperature is 60-90° C., and the reaction time is 0.5-5 h.

8. The preparation method according to claim 6, characterized in that The temperature of the addition reaction is 60-90° C., and the time is 3-5 hours.

9. The preparation method according to claim 6, characterized in that The compounding temperature is 60-90° C. and the compounding time is 6-14 hours.

10. Use of the high-toughness polyurethane driven by sunlight for rapid self-repairing according to any one of claims 1 to 5 or the high-toughness polyurethane driven by sunlight for rapid self-repairing obtained by the preparation method according to any one of claims 6 to 9 in solar self-repairing materials.

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