Fluorescent chain extender, fluorescent antifouling self-repairing polyurethane and preparation method of fluorescent antifouling self-repairing polyurethane

Abstract

The invention belongs to the technical field of fluorescent polymers, and particularly relates to a fluorescent chain extender, fluorescent antifouling self-repairing polyurethane and a preparation method of the fluorescent antifouling self-repairing polyurethane. The fluorescent chain extender is 4-N-perfluorobutyl sulfonyl ethanediamine-N-(2-hydroxyl-1-hydroxymethyl ethyl)-1, 8-naphthalene dicarboxamide, and the structural formula (1) of the fluorescent chain extender is as shown in the specification. The fluorescent chain extender provided by the invention has a rigid naphthalene ring and a low-surface-energy fluoroalkyl structure, and by modifying polyurethane, the hydrogen-bond interaction in a polyurethane molecular chain, the mechanical hinging effect of the rigid naphthalene ring, the fluorescent property and the hydrophobic property can be improved, so that the polyurethane is endowed with the properties of fluorescence, antifouling property, high mechanical strength and self-repairing. A rigid structure contained in a molecular chain structure of the synthesized multifunctional polyurethane is easy to form crystals through a mechanical hinging effect between molecules and a rigid center, so that the stability of a connected fluorine-containing chain segment on a two-phase interface can be ensured, and a structure rearrangement phenomenon is not easy to occur. And # imgabs0 #.

Description

Technical Field

[0001] The present invention belongs to the technical field of fluorescent polymers, and particularly relates to a fluorescent chain extender, a fluorescent antifouling self-repairing polyurethane, and a preparation method thereof. Background Art

[0002] Waterborne polyurethane is a new type of polymer material, which is an aqueous dispersion prepared by reacting polyurethane resin with an aqueous solvent or an aqueous emulsifier. Compared with traditional organic solvent-based polyurethanes, waterborne polyurethanes have the advantages of environmental protection, non-toxicity, odorlessness, easy processing, convenient use, and low cost, and thus have been widely used in recent years.

[0003] With the improvement of living standards, people's requirements for materials are no longer limited to single performance indicators, but more require materials to have multiple functions. Therefore, materials with multifunctionality have become a research hotspot. Fluorescent waterborne polyurethane has good water resistance, weather resistance, chemical corrosion resistance, and good flexibility. At the same time, it also has a fluorescent effect, which can improve the visibility of the material, making it easier to be discovered in a dim environment. It is of great significance to be applied in night construction or occasions where high visibility is required. Therefore, it is widely used in fields such as anti-counterfeiting materials, architectural coatings, fluorescent coatings, waterproof coatings, sealing materials, and ship coatings.

[0004] Currently, there are various ways to endow waterborne polyurethane with fluorescent properties and other properties, such as doping fluorescent substances in polyurethane emulsion by physical blending method or binding fluorescent substances to the polyurethane molecular chain by chemical bonding. For example, Chinese Patent CN115991854A, a polyurethane material with fluorescent and antibacterial properties and its preparation method, prepared product 1 and product 2, and then introduced the two products into the reaction of polyurethane to play a modification role, so that the polyurethane material has fluorescent and antibacterial properties. Chinese Patent CN116478366A, a fluorescent polyurethane material, its preparation method and application, prepared a borate compound M to modify polyurethane, so that the polyurethane has fluorescent and repairable functions. Chinese Patent CN117586471A, a self-repairing superhydrophobic polyurethane with fluorescent properties and its preparation method, reacted with aminophenylboronic acid to obtain a polyurethane emulsion, and then blended it with modified nano-silica, thereby having fluorescent and hydrophobic properties. Chinese Patent CN116622045A, a fluorescent polyurethane material containing curcumin, its preparation method and application, dissolved curcumin in a liquid containing a chain extender, and then reacted it with a polyurethane prepolymer to obtain a fluorescent polyurethane emulsion.

[0005] In the above research, the preparation of functional polyurethane is often obtained by modifying polyurethane with functional chain extenders. However, the introduced functional chain extenders can only endow polyurethane with fluorescence properties or / and self-healing properties. For multifunctional polyurethane, chain extenders or hydrophobic materials with multiple functions need to be introduced again. Therefore, it is of great significance to construct a multifunctional chain extender with fluorescence properties, hydrophobic properties, self-healing properties and good mechanical properties at the same time. Summary of the Invention

[0006] To solve the above problems, the present invention provides a fluorescent chain extender, a fluorescent antifouling self-healing polyurethane and a preparation method thereof. The fluorescent chain extender provided by the present invention has a rigid naphthalene ring and a low surface energy fluoroalkyl structure. By modifying polyurethane with it, the hydrogen bond interaction, the mechanical hinge action of the rigid naphthalene ring, the fluorescence properties and the hydrophobic properties in the polyurethane molecular chain can be increased, so as to endow polyurethane with properties in terms of fluorescence, antifouling, high mechanical strength and self-healing. The preparation method is simple, has few steps and mild reactions.

[0007] The present invention solves the above technical problems through the following technical solutions.

[0008] The first object of the present invention is to provide a fluorescent chain extender, and the fluorescent chain extender is 4-N-perfluorobutanesulfonyl ethylenediamine-N-(2-hydroxy-1-hydroxymethylethyl)-1,8-naphthalenedicarboxamide, and its structure is as shown in formula (1): .

[0009] The second object of the present invention is to provide a preparation method of the above fluorescent chain extender, including the following steps: S1. Using ethylenediamine and perfluorobutanesulfonyl fluoride as raw materials, carrying out a nucleophilic substitution reaction at 0 °C to 5 °C to obtain N-aminoethyl-perfluorobutanesulfonamide.

[0010] S2. Using 4-bromo-1,8-naphthalic anhydride and 2-amino-1,3-propanediol as raw materials, dissolving them in a first solvent, and carrying out an acylation reaction at 70 °C to 90 °C to obtain an intermediate product.

[0011] S3. Using N-aminoethyl-perfluorobutanesulfonamide and the intermediate product, dissolving them in a second solvent, and carrying out an alkylation reaction at 90 °C to 110 °C to obtain 4-N-perfluorobutanesulfonyl ethylenediamine-N-(2-hydroxy-1-hydroxymethylethyl)-1,8-naphthalenedicarboxamide.

[0012] Furthermore, the molar ratio of ethylenediamine to perfluorobutanesulfonyl fluoride is 3 to 7:1, and the time of the nucleophilic substitution reaction is 4 h to 6 h.

[0013] Further, the molar ratio of 4-bromo-1,8-naphthalic anhydride to 2-amino-1,3-propanediol is 1:2 to 5, the dosage of the first solvent is 20 times the total mass of 4-bromo-1,8-naphthalic anhydride and 2-amino-1,3-propanediol, the first solvent is ethanol, and the reaction time is 9 h.

[0014] Further, the molar ratio of the intermediate product to N-aminoethyl-perfluorobutylsulfonamide is 1:2 to 5, the dosage of the second solvent is 15 times the total mass of the intermediate product and N-aminoethyl-perfluorobutylsulfonamide, the second solvent is dimethyl sulfoxide, and the reaction time is 8 h.

[0015] The third object of the present invention is to provide a preparation method of a fluorescent antifouling self-repairing polyurethane, comprising the following steps: Using diisocyanate and oligomeric polyol as raw materials, under a catalyst system, a first polymerization reaction is carried out at 70°C to 90°C, and then a hydrophilic chain extender, 1,4-butanediol and the fluorescent chain extender described in claim 1 are sequentially added, and a second polymerization reaction is carried out at 70°C to 90°C to obtain an -NCO-terminated fluorescent polyurethane prepolymer; At 70°C to 90°C, perfluorohexyl ethanol is added to the -NCO-terminated fluorescent polyurethane prepolymer to perform unilateral capping on the polyurethane prepolymer, and then a crosslinking agent is added to carry out a crosslinking reaction to obtain a fluorescent multifunctional chain extender modified polyurethane system; The temperature of the system is lowered to 35°C to 45°C, and then a neutralizing agent is added for neutralization. Under stirring conditions, water is added for dispersion and emulsification. After removing the solvent, a fluorescent antifouling self-repairing polyurethane is obtained.

[0016] Further, the molar ratio of diisocyanate to oligomeric polyol is 1:0.2 to 0.4; the molar ratio of diisocyanate, hydrophilic chain extender and fluorescent chain extender is 1:0.2 to 0.3:0.1 to 0.2; the molar ratio of diisocyanate to 1,4-butanediol is 1:0.2 to 0.3; the molar ratio of diisocyanate, perfluorohexyl ethanol and crosslinking agent is 1:0.1 to 0.2:0.04 to 0.06; the dosage of the neutralizing agent is 0.2 to 0.3 times the molar amount of diisocyanate; the solid content of the fluorescent antifouling self-repairing polyurethane is 25% to 60%; the solid content of the fluorescent antifouling self-repairing polyurethane is 30%.

[0017] Further, the diisocyanate is one of isophorone diisocyanate or 2,4-toluene diisocyanate; the molecular weight of the oligomeric polyol is 1000-3000, and the oligomeric polyol is one of polyethylene glycol, polytetrahydrofuran diol, polybutylene adipate, or polycarbonate diol; the hydrophilic chain extender is dimethylolpropionic acid or dimethylolbutyric acid; the crosslinking agent is one of trimethylolpropane or pentaerythritol; the neutralizing agent is one of triethylamine, triethanolamine, or N-methyldiethanolamine.

[0018] Further, the dosage of the catalyst is 0.01% - 0.05%, the time of the first polymerization reaction is 0.5 h - 1 h, the time of the second polymerization reaction is 2 h - 3 h, the time of single-side capping is 2 h - 3 h, the time of the crosslinking reaction is 1 h - 1.5 h, and the time of neutralization is 1 h - 1.5 h; the conditions for removing the solvent are: rotary evaporation at 40°C - 60°C and -0.1 to -0.2 MPa for 0.5 h - 1 h.

[0019] The fourth object of the present invention is to provide a fluorescent antifouling self-healing polyurethane prepared by the above preparation method.

[0020] The present invention has the following beneficial effects compared with the prior art: The fluorescent chain extender provided by the present invention has a rigid naphthalene ring and a low surface energy fluoroalkyl structure. By modifying the polyurethane with it, the hydrogen bond interaction, the mechanical hinge effect of the rigid naphthalene ring, the fluorescent property, and the hydrophobic property in the polyurethane molecular chain can be increased, thereby endowing the polyurethane with the properties of fluorescence, antifouling, high mechanical strength, and self-healing.

[0021] The present invention uses perfluorobutanesulfonyl fluoride and ethylenediamine as raw materials to prepare the intermediate N-aminoethyl-perfluorobutanesulfonamide through an acylation reaction, and then uses 4-bromo-1,8-naphthalic anhydride and 2-amino-1,3-propanediol as raw materials to prepare another intermediate 4-bromo-N-(2-hydroxy-1-hydroxymethylethyl)-1,8-naphthalenedicarboxamide through an acylation reaction. Finally, the two intermediates are used to prepare a fluorescent chain extender containing a rigid naphthalene ring and a low surface energy fluoroalkyl group through an alkylation reaction, which has good application prospects in the field of fluorescent antifouling self-healing high-strength multifunctional polyurethanes.

[0022] In this invention, a prepolymer is prepared with diisocyanate as the hard segment and oligomeric polyol as the soft segment, and then it is modified with a hydrophilic chain extender and a fluorescent multifunctional chain extender. Perfluorohexyl ethanol is used to cap one side of the polyurethane macromolecular chain, and then a crosslinking agent is used for moderate crosslinking. Subsequently, it is neutralized with a neutralizing agent and dispersed by high-speed stirring with water to prepare a polyurethane emulsion. The rigid structure contained in the designed and synthesized multifunctional polyurethane molecular chain is prone to form crystals through intermolecular and mechanical hinge actions at the rigid centers, which can ensure the stability of the connected fluorine-containing chain segments at the two-phase interface, and is not prone to structural rearrangement, having excellent hydrophobic stability. The prepared multifunctional polyurethane material has strong fluorescence effects, hydrophobic properties, mechanical and self-healing properties. Therefore, the application fields of this invention are extensive, such as in anti-counterfeiting labels, fluorescent inks and coatings, anti-fouling, waterproof and anti-corrosion coatings or films, building materials, elastic materials and other fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 FIG. is the infrared spectra of reactant BA, intermediate product BAA, PFSF-E and fluorescent multifunctional chain extender BA-F prepared in Example 1 of the present invention.

[0024] Figure 2 FIG. is the optical photograph of the polyurethane emulsion prepared in Example 1 of the present invention at different concentrations. Figure 2 In (a), it is the optical photograph under visible light, and in (b), it is the optical photograph under ultraviolet light.

[0025] Figure 3 FIG. is the photograph of the water contact angle on the surface of the film formed from the polyurethane emulsion prepared in Example 1 of the present invention.

[0026] Figure 4 FIG. is the self-healing diagram of the polyurethane emulsion prepared in Example 1 of the invention. Figure 4 In (a), it is 0 h, in (b), it is 3 h, in (c), it is 6 h, and in (d), it is 9 h.

[0027] Figure 5 FIG. is the stress-strain curve diagram of the polyurethane films prepared in Examples 1 to 5 of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0028] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present invention.

[0029] It should be noted that the professional terms used in the present invention are only for the purpose of describing specific embodiments and are not intended to limit the protection scope of the present invention. In the present invention, certain terms are used to refer to specific components. Those skilled in the art should understand that technicians may use different nouns to refer to the same component. The present invention does not distinguish components by the difference in nouns, but by the difference in the functions of components. As mentioned throughout the specification and claims, "including" is an open-ended term and should be understood as "including but not limited to".

[0030] In the prior art, the preparation of functional polyurethane is often obtained by modifying polyurethane with a functional chain extender. However, the introduced functional chain extender can only endow polyurethane with fluorescence properties or / and self-healing properties. For multifunctional polyurethane, a chain extender or hydrophobic material with multiple functions needs to be introduced again. Therefore, it is of great significance to construct a multifunctional chain extender with fluorescence properties, hydrophobic properties, self-healing properties and good mechanical properties.

[0031] Based on the above problems, the present invention provides a fluorescent chain extender, and the fluorescent chain extender is 4-N-perfluorobutanesulfonyl ethylenediamine-N-(2-hydroxy-1-hydroxymethylethyl)-1,8-naphthalenedicarboxamide, and its structure is shown in formula (1): 。

[0032] The fluorescent chain extender provided by the present invention has a rigid naphthalene ring and a low surface energy fluoroalkyl structure. By modifying polyurethane with it, the hydrogen bond interaction, the mechanical hinge action of the rigid naphthalene ring, the fluorescence properties and the hydrophobic properties in the polyurethane molecular chain can be increased, so as to endow polyurethane with fluorescence, antifouling, high mechanical strength and self-healing properties at the same time.

[0033] The present invention also provides a preparation method of the above fluorescent chain extender, which includes the following steps: S1. Using ethylenediamine and perfluorobutanesulfonyl fluoride as raw materials, an amidation reaction is carried out at 0°C to 5°C to obtain N-aminoethyl-perfluorobutanesulfonamide. Its reaction route is as follows:

[0034] 。

[0035] S2. Using 4-bromo-1,8-naphthalic anhydride and 2-amino-1,3-propanediol as raw materials, dissolving them in a first solvent, and carrying out an acylation reaction at 70°C to 90°C to obtain an intermediate product. Its reaction route is as follows:

[0036] 。

[0037] S3. Dissolve N-aminoethyl-perfluorobutanesulfonamide and the intermediate product in a second solvent, and carry out an alkylation reaction at 90 °C to 110 °C to obtain 4-N-perfluorobutanesulfonyl ethylenediamine-N-(2-hydroxy-1-hydroxymethylethyl)-1,8-naphthalenedicarboxamide. The reaction route is as follows:

[0038] .

[0039] In the present invention, first, the intermediate product N-aminoethyl-perfluorobutanesulfonamide was prepared by an acylation reaction using perfluorobutanesulfonyl fluoride and ethylenediamine as raw materials. Then, another intermediate product 4-bromo-N-(2-hydroxy-1-hydroxymethylethyl)-1,8-naphthalenedicarboxamide was prepared by an acylation reaction using 4-bromo-1,8-naphthalic anhydride and 2-amino-1,3-propanediol as raw materials. Finally, a fluorescent chain extender containing a rigid naphthalene ring and a low surface energy fluoroalkyl group in the molecule was prepared by alkylation reaction of the two intermediate products, which has good application prospects in the field of fluorescent antifouling self-healing high-strength multifunctional polyurethane.

[0040] In some embodiments, the molar ratio of ethylenediamine to perfluorobutanesulfonyl fluoride is 3 to 7:1, and the amideification reaction time is 4 h to 8 h. In a preferred embodiment, the molar ratio of ethylenediamine to perfluorobutanesulfonyl fluoride is 5:1.

[0041] In some embodiments, the molar ratio of 4-bromo-1,8-naphthalic anhydride to 2-amino-1,3-propanediol is 1:2 to 5, the amount of the first solvent is 15 to 25 times the total mass of 4-bromo-1,8-naphthalic anhydride and 2-amino-1,3-propanediol, the first solvent is ethanol, and the acylation reaction time is 8 h to 10 h. In a preferred embodiment, the molar ratio of 4-bromo-1,8-naphthalic anhydride to 2-amino-1,3-propanediol is 1:3, and the amount of the first solvent is 20 times the total mass of 4-bromo-1,8-naphthalic anhydride and 2-amino-1,3-propanediol.

[0042] In some embodiments, the molar ratio of the intermediate product to N-aminoethyl-perfluorobutanesulfonamide is 1:2 to 5, the amount of the second solvent is 10 to 20 times the total mass of the intermediate product and N-aminoethyl-perfluorobutanesulfonamide, the second solvent is dimethyl sulfoxide, and the alkylation reaction time is 7 h to 9 h. In a preferred embodiment, the molar ratio of the intermediate product to N-aminoethyl-perfluorobutanesulfonamide is 1:3, and the amount of the second solvent is 15 times the total mass of the intermediate product and N-aminoethyl-perfluorobutanesulfonamide.

[0043] In addition, the present invention also provides a method for preparing the above-mentioned fluorescent antifouling self-healing polyurethane, comprising the following steps: Step 1: Using diisocyanate and oligomeric polyol (molecular weight 1000 - 3000) as raw materials, under a catalyst system, conduct the first polymerization reaction at 70°C - 90°C. Then, successively add a hydrophilic chain extender, 1,4-butanediol, and a fluorescent chain extender, and conduct the second polymerization reaction at 70°C - 90°C to obtain an -NCO-terminated fluorescent polyurethane prepolymer. The reaction route is as follows:

[0044] 。

[0045] Step 2: At 70°C - 90°C, add perfluorohexylethanol to the -NCO-terminated fluorescent polyurethane prepolymer to conduct single-side capping on the polyurethane prepolymer, and then add a crosslinking agent to conduct a crosslinking reaction to obtain a fluorescent multi-functional chain extender modified polyurethane system. The reaction route is as follows:

[0046] 。

[0047] Step 3: Lower the system temperature to 35°C - 45°C, then add a neutralizing agent for neutralization. Under stirring conditions, add water for dispersion and emulsification. After removing the solvent, obtain fluorescent antifouling self-healing polyurethane. The reaction route is as follows:

[0048] 。

[0049] It should be noted that in the present invention, prepolymerization is carried out through the polyaddition reaction between diisocyanate and oligomeric polyol, and then chain extension modification is carried out by a hydrophilic chain extender, a small molecule chain extender, and a fluorescent multi-functional chain extender. Single-side capping is carried out with perfluorohexylethanol, moderate crosslinking is carried out with a crosslinking agent, and then neutralization and high-speed stirring and dispersion with water are carried out to prepare a polyurethane emulsion. The prepared polyurethane emulsion can synergistically exert the "hinging" effect and fluorescence of the rigid naphthalene ring center in the molecular chain of the fluorescent multi-functional chain extender, the hydrophobic effect of low surface energy perfluorobutyl and perfluorohexyl, the crosslinking effect of the crosslinking agent, and the hydrogen bond effect between the hard and soft segments of the polyurethane, so that the polyurethane has multi-functions such as fluorescence performance, hydrophobic performance, self-healing, and high mechanical properties at the same time.

[0050] In some embodiments, the molar ratio of diisocyanate to oligomeric polyol is 1:0.2 - 0.4; the molar ratio of diisocyanate, hydrophilic chain extender, and fluorescent chain extender is 1:0.2 - 0.3:0.1 - 0.2; the molar ratio of diisocyanate to 1,4-butanediol is 1:0.2 - 0.3; the molar ratio of diisocyanate, perfluorohexylethanol, and crosslinking agent is 1:0.1 - 0.2:0.04 - 0.06; the dosage of the neutralizing agent is 0.2 - 0.3 times the molar amount of diisocyanate; the solid content of the fluorescent antifouling self-healing polyurethane is 25% - 60%.

[0051] In some embodiments, the diisocyanate is one of isophorone diisocyanate or 2,4-toluene diisocyanate. The molecular weight of the oligomeric polyol is 1000 - 3000, and the oligomeric polyol is one of polyethylene glycol, polytetrahydrofuran diol, polybutylene adipate, or polycarbonate diol. The hydrophilic chain extender is dimethylolpropionic acid or dimethylolbutyric acid. The crosslinking agent is one of trimethylolpropane or pentaerythritol. The neutralizing agent is one of triethylamine, triethanolamine, or N-methyldiethanolamine.

[0052] In some embodiments, the dosage of the catalyst is 0.01% - 0.05% of the total mass of the diisocyanate and the oligomeric polyol. The time for the first polymerization reaction is 0.5 h - 1 h, the time for the second polymerization reaction is 2 h - 3 h, the time for single-sided capping is 2 h - 3 h, the time for the crosslinking reaction is 1 h - 1.5 h, and the time for neutralization is 1 h - 1.5 h. Rotary evaporation is carried out at 40°C - 60°C and -0.1 MPa - -0.2 MPa for 0.5 h - 1 h.

[0053] The present invention also provides a fluorescent antifouling self-healing polyurethane, which is prepared by using the preparation method of the above-mentioned fluorescent antifouling self-healing polyurethane. It should be noted that in the present invention, the diisocyanate is used as the hard segment and the oligomeric polyol is used as the soft segment for prepolymerization, and then modified by a hydrophilic chain extender and a fluorescent multifunctional chain extender. Perfluorohexylethanol is used to cap one side of the polyurethane macromolecular chain, and then the crosslinking agent is used for moderate crosslinking, and then neutralized by a neutralizing agent and dispersed by high-speed stirring with water to prepare a polyurethane emulsion. The polyurethane emulsion prepared by this method can synergistically exert the "hinging" effect and fluorescence of the rigid naphthalene ring center in the molecular chain of the fluorescent multifunctional chain extender, the hydrophobic effect of the low surface energy perfluorobutyl and perfluorohexyl groups, the crosslinking effect of the crosslinking agent, and the hydrogen bond effect between the hard and soft segments of the polyurethane, thereby endowing the polyurethane with multifunctions such as fluorescence performance, hydrophobic performance, self-healing, and high mechanical properties.

[0054] The following is further illustrated by specific examples.

[0055] Example 1 A preparation method of a fluorescent antifouling self-healing polyurethane includes the following steps: S1. Preparation of the fluorescent multifunctional chain extender: Under ice bath conditions, first add 3.00 g (50 mmol) of ethylenediamine into a three-necked flask equipped with a stirring device, and then weigh 3.02 g (10 mmol) of perfluorobutanesulfonyl fluoride in a constant pressure funnel and slowly drop it into the above three-necked flask. After the dropping is completed, react for another 5 h. After the reaction is completed, use a rotary evaporator to remove the excessive ethylenediamine to obtain a small amount of yellow viscous liquid. Add a large amount of deionized water for washing and filtration, and finally obtain a white solid product N-aminoethyl-perfluorobutanesulfonamide, denoted as PFSF-E.

[0056] In a new three-necked flask equipped with a stir bar and a condenser, 2.77 g (10 mmol) of 4-bromo-1,8-naphthalic anhydride (BA) and 2.73 g (30 mmol) of 2-amino-1,3-propanediol were successively added. Then, 110 mL of ethanol was added and stirred until dissolved. The mixture was continuously stirred and reacted at 80 °C for 9 h. After the reaction was completed, the excess ethanol was removed using a rotary evaporator. The sample was washed repeatedly with deionized water three times and dried in vacuo at 50 °C for 12 h to obtain a light gray powder, denoted as intermediate product BAA.

[0057] In a new three-necked flask equipped with a stir bar and a condenser, 1.75 g (5 mmol) of BAA and 5.13 g (15 mmol) of PFSF-E were successively added. Then, 100 mL of dimethyl sulfoxide (DMSO) was added and stirred until dissolved. The three-necked flask was placed in an oil bath at 100 °C and heated under reflux for 8 h. After the reaction was completed, the solution was poured into 150 mL of deionized water and filtered. Then, it was washed repeatedly with deionized water three times and dried in vacuo at 50 °C for 12 h to obtain a yellow powder. Finally, the dried yellow powder was purified by silica gel chromatography to obtain a brown solid product, namely the fluorescent multifunctional chain extender BA-F.

[0058] S2. Preparation of fluorescent antifouling self-healing high-strength "four-in-one" functional polyurethane: In a three-necked flask equipped with a stirring device, 11.11 g of isophorone diisocyanate, 16.67 g of polybutylene adipate, and 8 mg of dibutyltin dilaurate as a catalyst were added. The reaction was carried out at 80 °C for 1 h. Subsequently, 1.68 g of dimethylolpropionic acid, 1.04 g of 1,4-butanediol, and the fluorescent multifunctional chain extender BA-F obtained from 0.7 g of S1 were added to the system, and the reaction was carried out for 2 h to obtain an -NCO-terminated fluorescent polyurethane prepolymer.

[0059] Under the condition of a temperature of 80 °C, 3.03 g of perfluorohexyl ethanol was slowly added dropwise to the above reaction system, and the mixture was heated and stirred for 3 h to perform single-side capping on the polyurethane prepolymer. Then, 0.37 g of trimethylolpropane was slowly added dropwise, and the reaction was carried out for 1 h to obtain a fluorescent multifunctional chain extender-modified polyurethane.

[0060] The temperature of the above system was lowered to 40 °C, 1.26 g of triethylamine was added to neutralize the reaction for 0.5 h. Then, under the condition of high-speed stirring, 84 g of deionized water was slowly added, and the mixture was dispersed and emulsified for 1 h. Then, the solvent was removed by rotary evaporation at 50 °C and -0.1 MPa for 0.5 h to obtain a fluorescent antifouling self-healing high-strength "four-in-one" functional polyurethane emulsion.

[0061] Example 2 A preparation method of a fluorescent antifouling self-healing polyurethane, comprising the following steps: S1. Preparation of Fluorescent Multifunctional Chain Extender: Under ice bath conditions, first add 3.00 g (50 mmol) of ethylenediamine into a three-necked flask equipped with a stirring device. Then weigh 3.02 g (10 mmol) of perfluorobutanesulfonyl fluoride into a constant pressure funnel and slowly add it dropwise to the above three-necked flask. After the addition is completed, react for another 5 h. After the reaction is completed, use a rotary evaporator to remove the excessive ethylenediamine to obtain a small amount of yellow viscous liquid. Add a large amount of deionized water for washing, filter, and finally obtain a white solid product N-aminoethyl-perfluorobutanesulfonamide, denoted as PFSF-E.

[0062] In a new three-necked flask equipped with a stirrer and a condenser, successively add 2.77 g (10 mmol) of 4-bromo-1,8-naphthalic anhydride and 2.73 g (30 mmol) of 2-amino-1,3-propanediol, then add 110 mL of ethanol and stir to dissolve. Stir and react at 80 °C for 9 h. After the reaction is completed, use a rotary evaporator to remove the excessive ethanol. Wash the sample with deionized water repeatedly for 3 times and dry it in vacuo at 50 °C for 12 h to obtain a light gray powder, denoted as intermediate product BAA.

[0063] In a new three-necked flask equipped with a stirrer and a condenser, successively add 1.75 g (5 mmol) of BAA and 5.13 g (15 mmol) of PFSF-E, then add 100 mL of DMSO and stir to dissolve. Place the three-necked flask in a heating reflux at 100 °C for 8 h. After the reaction is completed, pour the solution into 150 mL of deionized water and filter, then wash it with deionized water repeatedly for 3 times and dry it in vacuo at 50 °C for 12 h to obtain a yellow powder. Finally, purify the dried yellow powder by silica gel chromatography to obtain a brown solid product, which is the fluorescent multifunctional chain extender BA-F.

[0064] S2. Preparation of Fluorescent Antifouling Self-Healing High-Strength "Four-in-One" Functional Polyurethane: In a three-necked flask equipped with a stirring device, add 8.71 g of toluene diisocyanate, 33.33 g of polyethylene glycol and 8 mg of dibutyltin dilaurate as a catalyst, and react at 80 °C for 1 h; subsequently, add 1.85 g of dimethylolbutyric acid, 1.04 g of 1,4-butanediol and 0.99 g of the fluorescent multifunctional chain extender BA-F obtained in S1 into the system and react for 2 h to prepare an -NCO-terminated fluorescent polyurethane prepolymer.

[0065] Under the condition of a temperature of 80 °C, slowly add 3.03 g of perfluorohexyl ethanol dropwise to the above reaction system, heat and stir for 3 h to perform one-sided capping on the polyurethane prepolymer; then slowly add 0.28 g of pentaerythritol and react for 1 h to prepare a fluorescent multifunctional chain extender-modified polyurethane.

[0066] Lower the system temperature to 40 °C, add 1.26 g of triethylamine to neutralize the reaction for 0.5 h. Then, under the condition of high-speed stirring, slowly add 118 g of deionized water, disperse and emulsify for 1 h. After that, rotary evaporate for 0.5 h at 50 °C and -0.1 MPa to remove the solvent, and obtain a polyurethane emulsion with fluorescence anti-fouling self-healing high-strength "four-in-one" function.

[0067] Example 3 A preparation method of a fluorescence anti-fouling self-healing polyurethane, comprising the following steps: S1. Preparation of a fluorescence multifunctional chain extender: Under ice bath conditions, first add 3.00 g (50 mmol) of ethylenediamine to a three-necked flask equipped with a stirring device. Then weigh 3.02 g (10 mmol) of perfluorobutanesulfonyl fluoride in a constant pressure funnel and slowly drop it into the above three-necked flask. After the dropping is completed, react for another 5 h. After the reaction is completed, use a rotary evaporator to remove the excess ethylenediamine to obtain a small amount of yellow viscous liquid. Add a large amount of deionized water for washing, filter, and finally obtain a white solid product N-aminoethyl-perfluorobutanesulfonamide, denoted as PFSF-E.

[0068] In a new three-necked flask equipped with a stirrer and a condenser, successively add 2.77 g (10 mmol) of 4-bromo-1,8-naphthalic anhydride and 2.73 g (30 mmol) of 2-amino-1,3-propanediol, then add 110 mL of ethanol and stir to dissolve. Stir and react at 80 °C for 9 h. After the reaction is completed, use a rotary evaporator to remove the excess ethanol. Wash the sample with deionized water repeatedly 3 times and vacuum dry at 50 °C for 12 h to obtain a light gray powder, denoted as intermediate product BAA.

[0069] In a new three-necked flask equipped with a stirrer and a condenser, successively add 1.75 g (5 mmol) of BAA and 5.13 g (15 mmol) of PFSF-E, then add 100 mL of dimethyl sulfoxide (DMSO) and stir to dissolve. Place the three-necked flask in a heating reflux reaction at 100 °C for 8 h. After the reaction is completed, pour the solution into 150 mL of deionized water and filter, then wash with deionized water repeatedly 3 times and vacuum dry at 50 °C for 12 h to obtain a yellow powder. Finally, purify the dried yellow powder by silica gel chromatography to obtain a brown solid product, which is the fluorescence multifunctional chain extender BA-F.

[0070] S2. Preparation of a fluorescence anti-fouling self-healing high-strength "four-in-one" function polyurethane: In a three-necked flask equipped with a stirring device, 11.11 g of isophorone diisocyanate, 16.67 g of polytetrahydrofuran diol, and 8 mg of dibutyltin dilaurate were added as a catalyst, and the reaction was carried out at 80 °C for 1 h; subsequently, 1.68 g of dimethylolpropionic acid, 1.04 g of 1,4-butanediol, and 0.7 g of the fluorescent multifunctional chain extender BA-F obtained from S1 were added to the system, and the reaction was carried out for 2 h to obtain an -NCO-terminated fluorescent polyurethane prepolymer.

[0071] Under the condition of a temperature of 80 °C, 3.03 g of perfluorohexyl ethanol was slowly added dropwise to the above reaction system, and the mixture was heated and stirred for 3 h to perform one-sided capping on the polyurethane prepolymer; then, 0.37 g of trimethylolpropane was slowly added dropwise, and the reaction was carried out for 1 h to obtain a fluorescent multifunctional chain extender-modified polyurethane.

[0072] The temperature of the above system was lowered to 40 °C, 1.86 g of triethanolamine was added for neutralization reaction for 0.5 h, and then, under the condition of high-speed stirring, 85 g of deionized water was slowly added, and after dispersion and emulsification for 1 h, the solvent was removed by rotary evaporation at 50 °C and -0.1 MPa for 0.5 h to obtain a polyurethane emulsion with fluorescent anti-fouling, self-healing, and high-strength "four-in-one" functions.

[0073] Example 4 A preparation method of a fluorescent anti-fouling and self-healing polyurethane, comprising the following steps: S1. Preparation of a fluorescent multifunctional chain extender: Under ice bath conditions, 3.00 g (50 mmol) of ethylenediamine was first added to a three-necked flask equipped with a stirring device, and then 3.02 g (10 mmol) of perfluorobutylsulfonyl fluoride was weighed in a constant pressure funnel and slowly added dropwise to the above three-necked flask. After the addition was completed, the reaction was carried out for another 5 h. After the reaction was completed, the excess ethylenediamine was removed using a rotary evaporator to obtain a small amount of yellow viscous liquid, which was washed with a large amount of deionized water, filtered, and finally a white solid product N-aminoethyl-perfluorobutylsulfonamide was obtained, denoted as PFSF-E.

[0074] In a new three-necked flask equipped with a stirrer bar and a condenser, 2.77 g (10 mmol) of 4-bromo-1,8-naphthalic anhydride and 2.73 g (30 mmol) of 2-amino-1,3-propanediol were added successively, and then 110 mL of ethanol was added and stirred to dissolve. The reaction was continuously stirred at 80 °C for 9 h. After the reaction was completed, the excess ethanol was removed using a rotary evaporator, the sample was washed with deionized water repeatedly 3 times, and vacuum dried at 50 °C for 12 h to obtain a light gray powder, denoted as intermediate product BAA.

[0075] In a new three-necked flask equipped with a stir bar and a condenser, 1.75 g (5 mmol) of BAA and 5.13 g (15 mmol) of PFSF-E were successively added, and then 100 mL of DMSO was added and stirred to dissolve. The three-necked flask was placed in a heating reflux reaction at 100 °C for 8 h. After the reaction was completed, the solution was poured into 150 mL of deionized water and filtered, then washed repeatedly with deionized water 3 times, and vacuum dried at 50 °C for 12 h to obtain a yellow powder. Finally, the dried yellow powder was purified by silica gel chromatography to obtain a brown solid product, which is the fluorescent multifunctional chain extender BA-F.

[0076] S2. Preparation of fluorescent antifouling self-healing high-strength "four-in-one" functional polyurethane: In a three-necked flask equipped with a stirring device, 11.11 g of isophorone diisocyanate, 16.67 g of polybutylene adipate, and 8 mg of dibutyltin dilaurate were added as a catalyst, and the reaction was carried out at 80 °C for 1 h; subsequently, 1.68 g of dimethylolpropionic acid, 1.04 g of 1,4-butanediol, and the fluorescent multifunctional chain extender BA-F obtained from 0.7 g of S1 were added to the system, and the reaction was carried out for 2 h to prepare an -NCO-terminated fluorescent polyurethane prepolymer.

[0077] Under the condition of a temperature of 80 °C, 3.03 g of perfluorohexyl ethanol was slowly added dropwise to the above reaction system, and the mixture was heated and stirred for 3 h to perform one-sided capping on the polyurethane prepolymer; then 0.37 g of trimethylolpropane was slowly added dropwise, and the reaction was carried out for 1 h to prepare a fluorescent multifunctional chain extender-modified polyurethane.

[0078] The temperature of the above system was lowered to 40 °C, 1.49 g of N-methyldiethanolamine was added to carry out a neutralization reaction for 0.5 h, and then under the condition of high-speed stirring, 84 g of deionized water was slowly added, and after dispersion and emulsification for 1 h, the solvent was removed by rotary evaporation at 50 °C and -0.1 MPa for 0.5 h to prepare a fluorescent antifouling self-healing high-strength "four-in-one" functional polyurethane emulsion.

[0079] Example 5 A preparation method of a fluorescent antifouling self-healing polyurethane, comprising the following steps: S1. Preparation of a fluorescent multifunctional chain extender: Under ice bath conditions, 3.00 g (50 mmol) of ethylenediamine was first added to a three-necked flask equipped with a stirring device, and then 3.02 g (10 mmol) of perfluorobutanesulfonyl fluoride was weighed in a constant pressure funnel and slowly added dropwise to the above three-necked flask. After the addition was completed, the reaction was carried out for another 5 h. After the reaction was completed, an excess of ethylenediamine was removed using a rotary evaporator to obtain a small amount of yellow viscous liquid, which was washed with a large amount of deionized water, filtered, and finally a white solid product N-aminoethyl-perfluorobutanesulfonamide was obtained, denoted as PFSF-E.

[0080] In a new three-necked flask equipped with a stir bar and a condenser, 2.77 g (10 mmol) of 4-bromo-1,8-naphthalic anhydride and 2.73 g (30 mmol) of 2-amino-1,3-propanediol were successively added. Then, 110 mL of ethanol was added and stirred until dissolved. The mixture was continuously stirred and reacted at 80 °C for 9 h. After the reaction was completed, the excess ethanol was removed using a rotary evaporator. The sample was washed repeatedly with deionized water three times and dried in vacuo at 50 °C for 12 h to obtain a light gray powder, denoted as intermediate product BAA.

[0081] In a new three-necked flask equipped with a stir bar and a condenser, 1.75 g (5 mmol) of BAA and 5.13 g (15 mmol) of PFSF-E were successively added. Then, 100 mL of DMSO was added and stirred until dissolved. The three-necked flask was placed in a heating reflux at 100 °C and reacted for 8 h. After the reaction was completed, the solution was poured into 150 mL of deionized water and filtered. Then, it was washed repeatedly with deionized water three times and dried in vacuo at 50 °C for 12 h to obtain a yellow powder. Finally, the dried yellow powder was purified by silica gel chromatography to obtain a brown solid product, which was the fluorescent multifunctional chain extender BA-F.

[0082] S2. Preparation of fluorescent antifouling self-healing high-strength "four-in-one" functional polyurethane: In a three-necked flask equipped with a stirring device, 11.11 g of isophorone diisocyanate, 16.67 g of polycarbonate diol, and 8 mg of dibutyltin dilaurate as a catalyst were added. The reaction was carried out at 80 °C for 1 h. Subsequently, 1.68 g of dimethylolpropionic acid, 1.04 g of 1,4-butanediol, and the fluorescent multifunctional chain extender BA-F obtained from 0.7 g of S1 were added to the system, and the reaction was carried out for 2 h to prepare an -NCO-terminated fluorescent polyurethane prepolymer.

[0083] Under the condition of a temperature of 80 °C, 3.03 g of perfluorohexyl ethanol was slowly added dropwise to the above reaction system, and the mixture was heated and stirred for 3 h to perform unilateral capping on the polyurethane prepolymer. Then, 0.37 g of trimethylolpropane was slowly added dropwise, and the reaction was carried out for 1 h to prepare a fluorescent multifunctional chain extender-modified polyurethane.

[0084] The temperature of the above system was lowered to 40 °C, 1.26 g of triethylamine was added to neutralize the reaction for 0.5 h. Then, under the condition of high-speed stirring, 84 g of deionized water was slowly added, and after dispersion and emulsification for 1 h, the solvent was removed by rotary evaporation at 50 °C and -0.1 MPa for 0.5 h to prepare a fluorescent antifouling self-healing high-strength "four-in-one" functional polyurethane emulsion.

[0085] The structures and properties of the fluorescent multifunctional chain extenders and the prepared polyurethane emulsions prepared in Examples 1 to 5 were tested, and the results are as follows: Figure 1 This is the infrared spectrum of reactant 4-bromo-1,8-naphthalic anhydride and intermediate products BAA, PFSF-E, and fluorescent multifunctional chain extender BA-F prepared in Example 1 of the present invention. As Figure 1 shown, the absorption peaks of the reaction raw material 4-bromo-1,8-naphthalic anhydride (BA) at 1782 cm -1 , 1731 cm -1 , and 1020 cm -1 belong to the stretching vibration absorption peaks of C=O and C-O of the anhydride group. There are characteristic absorption peaks belonging to the aromatic ring at positions such as 1402 cm -1 , 1502 cm -1 , 1585 cm -1 , and 779 cm -1 . The absorption peak at 555 cm -1 belongs to the stretching vibration absorption peak of C-Br. In comparison, the characteristic peaks of C=O and C-O of the anhydride group of intermediate BAA disappear, and new stretching vibration absorption peaks belonging to amide C=O and C-N appear at 1697 cm -1 , 1649 cm -1 , and 1043 cm -1 . The new absorption peak at 3388 cm -1 is the stretching vibration absorption peak of -OH, and the new peak at 426 cm -1 is the characteristic peak of the cyclic amide structure. The absorption peak of intermediate PFAS-E at 3222 cm -1 belongs to the stretching vibration absorption peak of -NH2. The absorption peaks at 524 cm -1 , 580 cm -1 , 1083 cm -1 , and 1137 cm -1 belong to the bending vibration and stretching vibration absorption peaks of -C-F. The characteristic absorption peak of -SO2-NH- appears at 1353 cm -1 . The stretching vibration absorption peaks of C-H appear at 2991 cm -1 and 2891 cm -1 . Compared with BAA, the stretching vibration peak of C-Br of BA-F disappears at 555 cm -1 . Moreover, the new absorption peaks of BA-F at 524 cm -1 , 582 cm -1 , 1083 cm -1 , and 1137 cm -1 are the bending vibration and stretching vibration absorption peaks of -C-F. The new characteristic absorption peak of -SO2-NH- appears at 1355 cm -1 . In summary, it shows that the fluorescent multifunctional chain extender BA-F has been successfully synthesized.

[0086] Figure 2 Optical photographs of the polyurethane emulsion prepared in Example 1 of the present invention at different concentrations. Figure 2 In it, a is the optical photograph under visible light, and b is the optical photograph under ultraviolet light. As Figure 2 shown, the polyurethane emulsions with different concentrations prepared in Example 1 appear milky white, light yellow and yellow respectively under visible light; and their colors change to blue-green, green and dark green respectively under ultraviolet light irradiation, indicating that the synthesized polyurethane emulsion has fluorescence.

[0087] Figure 3 Photograph of the water contact angle on the surface of the film formed from the polyurethane emulsion prepared in Example 1 of the present invention. As Figure 3 shown, the size of the static water contact angle on the surface of the latex film is 115.7°, indicating that it has good hydrophobicity.

[0088] Figure 4 Self-healing diagram of the film formed from the polyurethane emulsion prepared in Example 1 of the invention. Figure 4 In it, (a) is 0 h, (b) is 3 h, (c) is 6 h, and (d) is 9 h. As Figure 4 shown, when the two films just come into contact with each other after being cut, it can be clearly observed that there is a large gap between the two; after 3 hours, the two films have obviously re-bonded together and the gap becomes smaller; after 6 hours, the two films are almost bonded together and only a light line can be observed; after 9 hours, the two films have become a whole and the repair is completed, indicating that the polyurethane film has good self-healing performance.

[0089] The polyurethane emulsions prepared in Examples 1 to 5 were poured into a polytetrafluoroethylene plate and dried to form a film at 50 °C to obtain a polyurethane film. The thickness of the polyurethane film was measured, and the mechanical properties of the polyurethane films prepared in Examples 1 to 5 were tested. Figure 5 Stress-strain curve diagrams of the polyurethane films prepared in Examples 1 to 5 of the present invention. As Figure 5 shown, the stress of the polyurethane film is about 30 MPa to 38 MPa, and the strain is 460% to 650%, having good mechanical properties.

[0090] It should be noted that when the present invention involves a numerical range, it should be understood that both endpoints of each numerical range and any value between the two endpoints can be selected. Since the steps and methods adopted are the same as those in the embodiments, in order to prevent repetition, the present invention describes preferred embodiments. Although the preferred embodiments of the present invention have been described, those skilled in the art can make additional changes and modifications to these embodiments once they know the basic creative concept. Therefore, the appended claims are intended to be construed as including the preferred embodiments and all changes and modifications falling within the scope of the present invention.

[0091] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention is also intended to include these modifications and variations.

Claims

1. A fluorescent chain extender, characterized in that, The fluorescent chain extender is 4-N-perfluorobutanesulfonyl ethylenediamine-N-(2-hydroxy-1-hydroxymethylethyl)-1,8-naphthalenedicarboxamide, and its structure is shown in Formula (1): 。 2. The preparation method of the fluorescent chain extender according to claim 1, characterized in that, It includes the following steps: Using ethylenediamine and perfluorobutanesulfonyl fluoride as raw materials, carrying out an amidation reaction at 0°C to 5°C to obtain N-aminoethyl-perfluorobutanesulfonamide; Using 4-bromo-1,8-naphthalic anhydride and 2-amino-1,3-propanediol as raw materials, dissolving them in a first solvent, and carrying out an acylation reaction at 70°C to 90°C to obtain an intermediate product; Using N-aminoethyl-perfluorobutanesulfonamide and the intermediate product, dissolving them in a second solvent, and carrying out an alkylation reaction at 90°C to 110°C to obtain 4-N-perfluorobutanesulfonyl ethylenediamine-N-(2-hydroxy-1-hydroxymethylethyl)-1,8-naphthalenedicarboxamide.

3. The preparation method of the fluorescent chain extender according to claim 2, characterized in that, The molar ratio of ethylenediamine to perfluorobutanesulfonyl fluoride is 3 to 7:1, and the time of the amidation reaction is 4h to 8h.

4. The preparation method of the fluorescent chain extender according to claim 2, wherein The molar ratio of 4-bromo-1,8-naphthalic anhydride to 2-amino-1,3-propanediol is 1:2 to 5, the dosage of the first solvent is 15 to 25 times the total mass of 4-bromo-1,8-naphthalic anhydride and 2-amino-1,3-propanediol, the first solvent is ethanol, and the time of the acylation reaction is 8h to 10h.

5. The preparation method of the fluorescent chain extender according to claim 2, characterized in that, The molar ratio of the intermediate product to N-aminoethyl-perfluorobutanesulfonamide is 1:2 to 5, the dosage of the second solvent is 10 to 20 times the total mass of the intermediate product and N-aminoethyl-perfluorobutanesulfonamide, the second solvent is dimethyl sulfoxide, and the time of the alkylation reaction is 7h to 9h.

6. A preparation method of a fluorescent antifouling self-healing polyurethane, characterized in that, It includes the following steps: Using diisocyanate and oligomeric polyol as raw materials, carrying out a first polymerization reaction at 70°C to 90°C under a catalyst system, then successively adding a hydrophilic chain extender, 1,4-butanediol and the fluorescent chain extender described in Claim 1, and carrying out a second polymerization reaction at 70°C to 90°C to obtain an -NCO-terminated fluorescent polyurethane prepolymer; At 70°C to 90°C, adding perfluorohexyl ethanol to the -NCO-terminated fluorescent polyurethane prepolymer to carry out one-sided capping of the polyurethane prepolymer, and then adding a crosslinking agent to carry out a crosslinking reaction to obtain a fluorescent multifunctional chain extender modified polyurethane system; Lower the temperature of the system to 35°C to 45°C, then add a neutralizing agent for neutralization, under stirring conditions, add water for dispersion and emulsification, and after removing the solvent, obtain a fluorescent antifouling self-repairing polyurethane.

7. The preparation method of the fluorescent antifouling self-healing polyurethane according to claim 6, characterized in that, The molar ratio of diisocyanate to oligomeric polyol is 1:0.2 to 0.4; the molar ratio of diisocyanate, hydrophilic chain extender and fluorescent chain extender is 1:0.2 to 0.3:0.1 to 0.2; the molar ratio of diisocyanate to 1,4-butanediol is 1:0.2 to 0.3; the molar ratio of diisocyanate, perfluorohexyl ethanol and crosslinking agent is 1:0.1 to 0.2:0.04 to 0.06; the dosage of the neutralizing agent is 0.2 to 0.3 times the molar amount of diisocyanate; the solid content of the fluorescent antifouling self-repairing polyurethane is 25% to 60%.

8. The preparation method of the fluorescent anti-fouling self-healing polyurethane according to claim 6, characterized in that, The diisocyanate is one of isophorone diisocyanate or 2,4-toluene diisocyanate; the molecular weight of the oligomeric polyol is 1000 - 3000, and the oligomeric polyol is one of polyethylene glycol, polytetrahydrofuran diol, polybutylene adipate, or polycarbonate diol; the hydrophilic chain extender is dimethylolpropionic acid or dimethylolbutyric acid; the crosslinking agent is one of trimethylolpropane or pentaerythritol; the neutralizing agent is one of triethylamine, triethanolamine, or N-methyldiethanolamine.

9. The preparation method of the fluorescent anti-fouling self-healing polyurethane according to claim 6, wherein, The dosage of the catalyst is 0.01% - 0.05% of the total mass of the diisocyanate and the oligomeric polyol. The time for the first polymerization reaction is 0.5 h - 1 h, the time for the second polymerization reaction is 2 h - 3 h, the time for single-sided capping is 2 h - 3 h, the time for the crosslinking reaction is 1 h - 1.5 h, the time for neutralization is 1 h - 1.5 h. The conditions for removing the solvent are: rotary evaporation at 40°C - 60°C and -0.1 MPa - -0.2 MPa for 0.5 h - 1 h.

10. A fluorescent anti-fouling self-healing polyurethane, characterized in that, It is prepared by using the preparation method according to Claims 6 - 9.

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