A photocurable self-healing fluorosilicon superhydrophobic coating and its preparation method and application

Abstract

The present invention belongs to the technical field of the preparation of fluorosilicon materials, and particularly relates to a photocurable self-healing fluorosilicon superhydrophobic coating, a preparation method thereof and an application. A self-healing fluorosilicon superhydrophobic coating is synthesized by the step-by-step polymerization of a fluorinated polyol, an isocyanate, a silicon-containing small molecule monomer, a small molecule monomer containing a disulfide bond and a compound containing an adjacent double bond structure with an electron-withdrawing group. Meanwhile, a nano filler and a silane coupling agent are introduced into the system to enable the nano filler to be uniformly dispersed in the self-healing fluorosilicon superhydrophobic coating, increasing the surface roughness of the coating, thereby further improving the hydrophobicity of the self-healing fluorosilicon superhydrophobic coating. The self-healing fluorosilicon superhydrophobic coating not only has anti-fouling, self-cleaning, anti-fogging and defrosting properties, but also has a remarkable and efficient repair effect, and is mainly applicable to industries such as aerospace anti-icing.

Description

Technical Field

[0001] The present invention belongs to the technical field of fluorosilicon material preparation, and particularly relates to a photocurable self-healing fluorosilicon superhydrophobic coating, a preparation method thereof and an application thereof. Background Art

[0002] A fluorosilicon superhydrophobic coating refers to a synthetic polymer with fluorine atoms and silicon-oxygen bond units in the polymer main chain, and has excellent hydrophobicity, anti-fouling, self-cleaning, anti-fogging and anti-frosting properties. Due to the designability of the molecular structure and unique properties such as hydrophobicity, superhydrophobic materials play an irreplaceable role not only in traditional fields such as traditional fabrics, metal materials, mechanical engineering, and pipeline transportation, but also in emerging high-tech fields such as electronic instruments, multi-functional fabrics, special metals, and aerospace. Among them, in the aerospace field, with the rapid development of China's space technology in recent years, the design of aircraft has been developing towards high reliability and long life. During operation, the windward surface of the aircraft will quickly freeze and form ice accumulation. If it cannot be effectively solved, it will greatly reduce the service life of the aircraft and seriously endanger the safe flight of the aircraft. Therefore, the current demand for superhydrophobic materials is becoming more and more urgent.

[0003] Most traditional anti-icing methods choose to use physical heating, which brings certain potential risks to the aircraft itself, does not meet the requirements of high reliability and long life of the aircraft, and has a large mass, increasing the flight resistance of the aircraft. The superhydrophobic coating has excellent hydrophobicity, anti-fouling, self-cleaning and other advantages, which can ensure the reliability and safety of the aircraft while meeting its lightweight requirements. Although the superhydrophobic material has many advantages when applied to aircraft, during the use of the aircraft, it is inevitably affected by environmental factors such as light, high temperature, acid-base, and physical damage, which may cause the service life of the superhydrophobic coating to be greatly reduced or the material to break, lose its function, and even bring serious safety hazards. Therefore, certain physical and chemical modifications must be carried out on the superhydrophobic coating to improve its service life.

[0004] The concept of self - healing originated from the self - healing phenomenon in biology. Inspired by bionics, many polymer materials with self - healing properties have been designed and synthesized. They can detect cracks by themselves and fill and repair the cracks through certain mechanisms, thus effectively improving the service life and safety of materials and reducing waste. Self - healing materials can be divided into intrinsic type and extrinsic type according to the repair principle. The extrinsic type is to encapsulate the repair agent in hollow structures such as microcapsules and liquid - core fibers. When the material is damaged, the repair agent can be released to repair the cracks. Although this method has a simple mechanism and a wide range of application fields, some limitations have been found in practical applications. For example, when the repair agent is consumed, the material loses its self - healing ability, and the voids left by microcapsules or liquid - core fibers may also cause new defects in the material. Therefore, intrinsic self - healing materials that are not restricted by the supply of repair agents are now more favored by researchers.

[0005] Intrinsic self - healing can be divided into self - healing of reversible non - covalent bonds such as reversible hydrogen bonds, reversible ionic bonds, reversible coordination bonds, and self - healing of reversible covalent bonds such as reversible Diels - Alder reactions and reversible disulfide bonds. Among them, self - healing materials prepared by using reversible covalent bond interactions have received increasing attention due to their excellent properties. Because these materials contain reversible dynamic bonds, that is, when the material breaks, these bonds can re - form bonding interactions with each other, thus achieving self - repair macroscopically. However, this type of repair method often requires specific conditions such as light, heat, electromagnetic fields, and humidity to trigger. Most of the existing self - healing coatings can only achieve self - healing at high temperatures, with too long repair time and too low efficiency. Summary of the Invention

[0006] The present invention provides a photocurable self - healing fluorosilicon super - hydrophobic coating and its preparation method. Through the synergistic effect of nano - fillers, silane coupling agents, and fluorinated polyols, the nano - fillers are evenly dispersed inside the polyurethane coating, which is beneficial to changing the microstructure of the polyurethane coating to increase its surface roughness and contact angle, greatly improving the hydrophobic performance of the polyurethane coating, and solving the problem that most self - healing super - hydrophobic coatings can only achieve self - healing at high temperatures, with too long repair time and too low efficiency. The self - healing fluorosilicon super - hydrophobic coating of the present invention is applied to the anti - icing field of aircraft in aerospace. This coating can achieve self - healing under heating conditions, greatly improving the service life of the super - hydrophobic coating, and then improving the service life of the aircraft and ensuring the safe use of the aircraft, with extremely high application value.

[0007] The present invention adopts the following technical solutions:

[0008] The self-healing fluorosilicon superhydrophobic coating is prepared by the stepwise polymerization of fluorinated polyols, isocyanates, silicon-containing small molecule monomers, small molecule monomers containing disulfide bonds, and compounds containing acrylate structures, and then adding nano-fillers and silane coupling agents. The reaction equation is as follows (where -NHCOO- can be replaced by -NHCONH-):

[0009]

[0010] The specific preparation method steps of the self-healing fluorosilicon superhydrophobic coating are as follows:

[0011] (1) Add a certain proportion of polyol to the bifunctional fluorinated carboxylic acid monomer, pass nitrogen for 10 min to remove the air in the system, and then heat and stir under nitrogen protection to obtain a colorless and transparent fluorinated polyol;

[0012] Among them, the bifunctional fluorinated carboxylic acid monomer is one of 2,2-bis(4-carboxyphenyl)hexafluoropropane, hexafluoroglutaric acid, perfluorodecanedioic acid, perfluorooctanedioic acid, or 2,2-difluoropentanedioic acid;

[0013] The polyol is one of polytetrahydrofuran ether diol, polypropylene glycol, polyethylene glycol, polylactic acid, or polycaprolactone diol.

[0014] The molar ratio of polyol to bifunctional fluorinated carboxylic acid monomer is 2:1.

[0015] (2) Place the polyol in a vacuum drying oven and dry it under vacuum at 120 °C for 2 h. Add isocyanate and an organotin catalyst to the obtained fluorinated polyol, dissolve it with an organic solvent, and stir at 30 - 40 °C for 2 h to obtain a viscous and transparent fluorinated polyisocyanate prepolymer SFPU-1;

[0016] Among them, the isocyanate is one of isophorone diisocyanate, 2,4-toluene diisocyanate, diphenylmethane diisocyanate, dicyclohexylmethane diisocyanate, or hexamethylene diisocyanate;

[0017] The organotin catalyst is one of dibutyltin dilaurate, stannous octoate, dodecyloxydimethyltin (DOS), tetrabutyloxytin (TBOT), or tributyloxymethyltin (TBTM).

[0018] The molar ratio of isocyanate to bifunctional fluorinated polyol is 3:1.

[0019] The addition amount of the organotin catalyst is 0.5% of the isocyanate.

[0020] (3) Sequentially add a small molecule chain extender containing silicon and having a dihydroxy or amino structure and a small molecule chain extender containing a disulfide bond and having a dihydroxy or amino structure, both dissolved in an organic solvent, to the prepolymer SFPU-1. The system undergoes a chain extension reaction at 30 - 40 °C for 1 h to obtain a viscous and transparent prepolymer SFPU-2;

[0021] Among them, the small molecule chain extender containing silicon and having a dihydroxy or amino structure is 4,4'-bis(dimethylhydroxysilyl)diphenyl ether, diphenylsilanediol, bis(tert-butylamino)silane, 3-[2-(2-aminoethylamino)ethylamino]propyl-trimethoxysilane, aminoethylaminoisobutylmethyldimethoxysilane;

[0022] The small molecule chain extender containing a disulfide bond and having a dihydroxy or amino structure is one of cystine, 4,4'-diaminodiphenyl disulfide, 4,4'-dihydroxydiphenyl disulfide;

[0023] The molar ratio of the small molecule chain extender containing silicon and having a dihydroxy or amino structure, the small molecule chain extender containing a disulfide bond and having a dihydroxy or amino structure, and the bifunctional fluorinated polyisocyanate prepolymer is 1∶1∶1.

[0024] (4) Add a capping agent containing an electron-withdrawing group adjacent to a double bond structure and having an amino or hydroxy group, dissolved in an organic solvent, to SFPU-2. The system undergoes a capping reaction at 30 - 40 °C for 1 h to obtain a viscous, transparent, and light yellow fluorosilicone polyurethane SFPU-3;

[0025] Among them, the capping agent containing an electron-withdrawing group adjacent to a double bond structure and having an amino or hydroxy group is 4-methylumbelliferone, 3-(acryloyloxy)-2-hydroxypropyl methacrylate, hydroxypropyl methacrylate, 2-(tert-butylamino)ethyl methacrylate, or 2-aminoethyl methacrylate. The molar ratio of the capping agent containing an acrylate structure and having an amino or hydroxy group to the bifunctional fluorinated polyisocyanate prepolymer is 2∶1.

[0026] The organic solvent used in each of the above steps is one of N,N-dimethylformamide, acetone, ethyl acetate, butyl acetate, toluene, xylene, dichloromethane, and tetrahydrofuran.

[0027] (5) Add the nano filler to absolute ethanol, stir well for dispersion, and perform ultrasonic treatment for 1 - 2 h. Then add it to SFPU-3 together with the silane coupling agent. The system is stirred at 30 - 40 °C for 2 h to obtain a viscous self-healing fluorosilicone polyurethane SFPU-4 containing nano filler;

[0028] Among them, the nano filler is one of nano silica, nano zinc oxide, nano titanium dioxide, and nano aluminum oxide. The dosage of the nano filler is 0.5 - 2 times the mass of the fluorosilicone polyurethane.

[0029] The silane coupling agent is one or more of γ-aminopropyltriethoxysilane, γ-(2,3-epoxypropoxy)propyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, γ-mercaptopropyltrimethoxysilane, N-(β-aminoethyl)-γ-aminopropylmethyldimethoxysilane, n-octyltriethoxysilane, 3-(trimethoxysilyl)-1-propylamine, vinyltriethoxysilane, vinyltriethoxysilane, vinylsilane, vinyltris(β-methoxyethoxy)silane, and the addition amount is 0.5-2 wt% of the mass of the nano filler.

[0030] (6) Slowly pour the viscous nano filler-containing self-healing fluorinated polyurethane SFPU-4 into the mold and irradiate it with UV light for 10 min to obtain the self-healing fluorosilicon superhydrophobic coating material.

[0031] Beneficial effects:

[0032] Through the synergistic effect of the nano filler, silane coupling agent, silicon-containing chain extender, and fluorinated polyol, the nano filler is evenly dispersed inside the polyurethane, which is beneficial to changing the micro-structure of the polyurethane coating to increase its surface roughness and contact angle, and greatly improves the hydrophobic performance of the polyurethane coating; on the basis of realizing the superhydrophobicity of the coating, through the action of reversible disulfide bonds, the superhydrophobic coating is endowed with efficient self-healing performance, and solves the problem that most self-healing superhydrophobic coatings can only achieve self-healing under high temperature or UV light irradiation and have too long repair time and too low efficiency. Description of the drawings

[0033] Figure 1 Infrared spectrum of the photocurable self-healing fluorosilicon superhydrophobic coating prepared in Example 1 using hexafluoroglutaric acid to prepare polyol and using 4,4'-bis(dimethylhydroxysilyl)diphenyl ether and L-cysteine as chain extenders.

[0034] Figure 2 Self-healing process diagram of the photocurable self-healing fluorosilicon superhydrophobic coating prepared in Example 1 using hexafluoroglutaric acid to prepare polyol and using 4,4'-bis(dimethylhydroxysilyl)diphenyl ether and L-cysteine as chain extenders when heated at 60 °C for 55 min.

[0035] Figure 3 Thermogravimetric analysis diagram of the photocurable self-healing fluorosilicon superhydrophobic coating prepared in Example 1 using hexafluoroglutaric acid to prepare polyol and using 4,4'-bis(dimethylhydroxysilyl)diphenyl ether and L-cysteine as chain extenders.

[0036] Figure 4Thermogravimetric rate graph of the photocurable self-healing fluorosilicon superhydrophobic coating prepared by using hexafluoroglutaric acid to prepare polyol in Example 1, with 4,4'-bis(dimethylhydroxysilyl)diphenyl ether and L-cysteine as chain extenders.

[0037] Figure 5 Comparison graph of water contact angles for Examples 1-15 and Comparative Examples 1-3. Detailed implementation manners

[0038] The technical solutions in the embodiments of the present invention will be clearly and completely described below. 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 implementation manners obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present invention.

[0039] Example 1

[0040] 1.2 g of bifunctional hexafluoroglutaric acid was added to 20 g of polycaprolactone diol (Mn = 2000). Nitrogen was passed for 10 min to remove the air in the system, and then it was heated and stirred under nitrogen protection to obtain a colorless and transparent fluorinated polyol. 20 g was taken and placed in a vacuum drying oven at 120 °C for vacuum drying for 2 h. The hydroxyl-terminated fluorinated polyol dissolved in 30 ml of N,N-dimethylformamide was added to a 100 ml three-necked flask dried in a blast drying oven and treated with nitrogen. 5.5 g of hexamethylene diisocyanate was added, and 0.028 g of dibutyltin dilaurate catalyst was added. The reaction was carried out with stirring at 40 °C for 2 h to obtain a viscous and transparent fluorinated polyisocyanate prepolymer SFPU-1. 4,4'-bis(dimethylhydroxysilyl)diphenyl ether (3.19 g) dissolved in 9.0 ml of N,N-dimethylformamide and L-cysteine (2.40 g) dissolved in 6.5 ml of N,N-dimethylformamide were successively added, and the reaction was carried out at 40 °C for 1 h to obtain a viscous and transparent prepolymer SFPU-2. Then 4-methylumbelliferone (3.52 g) dissolved in 5.0 ml of N,N-dimethylformamide was added, and the reaction was carried out at 40 °C for 1 h to obtain a viscous, transparent and light yellow fluorosilicon polyurethane SFPU-3. 25 g of hydrophobic nano-silica powder was weighed. The silica was added to 30 ml of anhydrous ethanol with a purity ≥ 99.7%, and magnetically stirred for 1 h. Then it was ultrasonically dispersed in an ultrasonic cleaner with a frequency of 40 KHz at room temperature for 30 min. Finally, it was dried and ground at 100 °C. The treated silica (20 g) and silane coupling agent KH550 (0.4 g) were simultaneously added to the reaction system, and the reaction was carried out with stirring at 40 °C for 2 h to obtain a viscous self-healing fluorosilicon polyurethane SFPU-4 containing nano-fillers. The viscous self-healing fluorosilicon polyurethane SFPU-4 containing nano-fillers was slowly poured into a mold and irradiated with UV light for 10 min to obtain a self-healing fluorosilicon superhydrophobic coating material.

[0041] To verify the self-healing performance of the self-healing superhydrophobic coating, after fixing the scratch length, it was placed under heating or different light conditions. The experiment found that the self-healing superhydrophobic coating could complete self-healing in 55 min under heating at 60 °C; the self-healing superhydrophobic coating could complete self-healing in 192 min under ultraviolet light irradiation. The water contact angle of the coating was tested using a JC2000D1 type contact angle measuring instrument, and the results are shown in Table 1.

[0042] Example 2

[0043] To 20 g of polycaprolactone diol (Mn = 2000), 2.0 g of bifunctional 2,2-bis(4-carboxyphenyl)hexafluoropropane was added. Nitrogen was passed through for 10 min to remove the air in the system, and then it was heated and stirred under nitrogen protection to obtain a colorless and transparent fluorinated polyol. The subsequent preparation of the self-healing fluorosilicon superhydrophobic coating material was the same as that in Example 1.

[0044] To verify the self-healing performance of the self-healing superhydrophobic coating, after fixing the scratch length, it was placed under heating or different light conditions. The experiment found that the self-healing superhydrophobic coating could complete self-healing in 59 min under heating at 60 °C; the self-healing superhydrophobic coating could not achieve self-healing under ultraviolet light irradiation. The water contact angle of the coating was tested using a JC2000D1 type contact angle measuring instrument, and the results are shown in Table 1.

[0045] Example 3

[0046] To 20 g of polycaprolactone diol (Mn = 2000), 1.5 g of bifunctional hexafluoroglutaric acid was added. Nitrogen was passed through for 10 min to remove the air in the system, and then it was heated and stirred under nitrogen protection to obtain a colorless and transparent fluorinated polyol. 20 g of the fluorinated polyol with a hydroxyl end group, which was placed in a vacuum drying oven at 120 °C for vacuum drying for 2 h and dissolved in 30 ml of N,N-dimethylformamide, was added to a 100 ml three-necked flask that had been dried in a blast drying oven and treated with nitrogen. 6.7 g of isophorone diisocyanate was added, and 0.034 g of dibutyltin dilaurate catalyst was added. The reaction was carried out under stirring at 40 °C for 2 h to obtain a viscous and transparent fluorinated polyisocyanate prepolymer SFPU-1. The subsequent preparation of the self-healing fluorosilicon superhydrophobic coating material was the same as that in Example 1.

[0047] To verify the self-healing performance of the self-healing superhydrophobic coating, after fixing the scratch length, it was placed under heating or different light conditions. The experiment found that the self-healing superhydrophobic coating could complete self-healing in 57 min under heating at 60 °C; the self-healing superhydrophobic coating could not achieve self-healing under ultraviolet light irradiation. The water contact angle of the coating was tested using a JC2000D1 type contact angle measuring instrument, and the results are shown in Table 1.

[0048] Example 4

[0049] 1.2 g of difunctional hexafluoroglutaric acid was added to 20 g of polycaprolactone diol (Mn = 2000). Nitrogen was passed through for 10 min to remove the air in the system. Then, it was heated and stirred under nitrogen protection to obtain a colorless and transparent fluorinated polyol. 20 g of the hydroxyl-terminated fluorinated polyol, which was placed in a vacuum drying oven at 120 °C for vacuum drying for 2 h and dissolved in 30 ml of N,N-dimethylformamide, was added to a 100 ml three-necked flask that had been dried in a blast drying oven and treated with nitrogen. 5.2 g of 2,4-toluene diisocyanate was added, and 0.026 g of dibutyltin dilaurate catalyst was added. The reaction was carried out with stirring at 40 °C for 2 h to obtain a viscous and transparent fluorinated polyisocyanate prepolymer SFPU-1. The preparation of the subsequent self-healing fluorosilicon superhydrophobic coating material was the same as in Example 1.

[0050] To verify the self-healing performance of the self-healing superhydrophobic coating, after fixing the scratch length, it was placed under heating or different light conditions. The experiment found that the self-healing superhydrophobic coating could complete self-healing in 62 min under heating at 60 °C; under ultraviolet light irradiation, the self-healing superhydrophobic coating could not achieve self-healing; the water contact angle of the coating was tested using a JC2000D1 type contact angle measuring instrument, and the results are shown in Table 1.

[0051] Example 5

[0052] 1.2 g of difunctional hexafluoroglutaric acid was added to 20 g of polycaprolactone diol (Mn = 2000). Nitrogen was passed through for 10 min to remove the air in the system. Then, it was heated and stirred under nitrogen protection to obtain a colorless and transparent fluorinated polyol. 20 g of the hydroxyl-terminated fluorinated polyol, which was placed in a vacuum drying oven at 120 °C for vacuum drying for 2 h and dissolved in 30 ml of N,N-dimethylformamide, was added to a 100 ml three-necked flask that had been dried in a blast drying oven and treated with nitrogen. 5.5 g of hexamethylene diisocyanate was added, and 0.028 g of dibutyltin dilaurate catalyst was added. The reaction was carried out with stirring at 40 °C for 2 h to obtain a viscous and transparent fluorinated polyisocyanate prepolymer SFPU-1. 2.16 g of diphenylsilanediol dissolved in 9.0 ml of N,N-dimethylformamide and 2.40 g of L-cysteine dissolved in 6.5 ml of N,N-dimethylformamide were added in sequence, and the reaction was carried out at 40 °C for 1 h to obtain a viscous and transparent prepolymer SFPU-2. The preparation of the subsequent self-healing fluorosilicon superhydrophobic coating material was the same as in Example 1.

[0053] To verify the self-healing performance of the self-healing superhydrophobic coating, after fixing the scratch length, it was placed under heating or different lighting conditions. The experiment found that the self-healing superhydrophobic coating could complete self-healing in 68 min under heating at 60 °C; the self-healing superhydrophobic coating could not achieve self-healing under ultraviolet light illumination; the water contact angle of the coating was tested using a JC2000D1 type contact angle measuring instrument, and the results are shown in Table 1.

[0054] Example 6

[0055] 1.2 g of bifunctional hexafluoroglutaric acid was added to 20 g of polycaprolactone diol (Mn = 2000), and nitrogen was passed through for 10 min to remove the air in the system. Then, it was heated and stirred under nitrogen protection to obtain a colorless and transparent fluorinated polyol; 20 g was taken and placed in a vacuum drying oven at 120 °C for vacuum drying for 2 h. The hydroxyl-terminated fluorinated polyol dissolved in 30 ml of N,N-dimethylformamide was added to a 100 ml three-necked flask dried in a blast drying oven and treated with nitrogen. 5.5 g of hexamethylene diisocyanate was added, and 0.028 g of dibutyltin dilaurate catalyst was added. The reaction was carried out with stirring at 40 °C for 2 h to obtain a viscous and transparent fluorinated polyisocyanate prepolymer SFPU-1; successively added aminoethylaminoisobutylmethyldimethoxysilane (2.21 g) dissolved in 9.0 ml of N,N-dimethylformamide and L-cysteine (2.40 g) dissolved in 6.5 ml of N,N-dimethylformamide, and the reaction was carried out at 40 °C for 1 h to obtain a viscous and transparent prepolymer SFPU-2; the preparation of the subsequent self-healing fluorosilicon superhydrophobic coating material was the same as in Example 1.

[0056] To verify the self-healing performance of the self-healing superhydrophobic coating, after fixing the scratch length, it was placed under heating or different lighting conditions. The experiment found that the self-healing superhydrophobic coating could complete self-healing in 63 min under heating at 60 °C; the self-healing superhydrophobic coating could not achieve self-healing under ultraviolet light illumination; the water contact angle of the coating was tested using a JC2000D1 type contact angle measuring instrument, and the results are shown in Table 1.

[0057] Example 7

[0058] 1.2 g of bifunctional hexafluoroglutaric acid was added to 20 g of polycaprolactone diol (Mn = 2000). Nitrogen was passed through for 10 min to remove the air in the system, and then it was heated and stirred under nitrogen protection to obtain a colorless and transparent fluorinated polyol. 20 g of the fluorinated polyol with hydroxyl end groups, which was placed in a vacuum drying oven at 120 °C for vacuum drying for 2 h and dissolved in 30 ml of N,N-dimethylformamide, was added to a 100 ml three-necked flask that had been dried in a blast drying oven and treated with nitrogen. 5.5 g of hexamethylene diisocyanate was added, and 0.028 g of dibutyltin dilaurate catalyst was added. The reaction was carried out with stirring at 40 °C for 2 h to obtain a viscous and transparent fluorinated polyisocyanate prepolymer SFPU-1. 4,4'-Bis(dimethylhydroxysilyl)diphenyl ether (3.19 g) dissolved in 9.0 ml of N,N-dimethylformamide and 4,4'-diaminodiphenyl disulfide (2.53 g) dissolved in 6.5 ml of N,N-dimethylformamide were added successively, and the reaction was carried out at 40 °C for 1 h to obtain a viscous and transparent prepolymer SFPU-2. Then 4-methylumbelliferone (3.52 g) dissolved in 5.0 ml of N,N-dimethylformamide was added, and the reaction was carried out at 40 °C for 1 h to obtain a viscous, transparent and light yellow fluorosilicon polyurethane SFPU-3. The preparation of the subsequent self-healing fluorosilicon superhydrophobic coating material was the same as in Example 1.

[0059] To verify the self-healing performance of the self-healing superhydrophobic coating, after fixing the scratch length, it was placed under heating or different light conditions. The experiment found that the self-healing superhydrophobic coating could complete self-healing in 66 min under heating at 60 °C; the self-healing superhydrophobic coating could not achieve self-healing under ultraviolet light illumination. The water contact angle of the coating was measured using a JC2000D1 type contact angle measuring instrument, and the results are shown in Table 1.

[0060] Example 8

[0061] 1.2 g of difunctional hexafluoroglutaric acid was added to 20 g of polycaprolactone diol (Mn = 2000). Nitrogen was passed through for 10 min to remove the air in the system, and then it was heated and stirred under nitrogen protection to obtain a colorless and transparent fluorinated polyol. 20 g of the hydroxyl-terminated fluorinated polyol, which was placed in a vacuum drying oven at 120 °C for vacuum drying for 2 h and dissolved in 30 ml of N,N-dimethylformamide, was added to a 100 ml three-necked flask that had been dried in a blast drying oven and treated with nitrogen. 5.5 g of hexamethylene diisocyanate was added, and 0.028 g of dibutyltin dilaurate catalyst was added. The reaction was carried out under stirring at 40 °C for 2 h to obtain a viscous and transparent fluorinated polyisocyanate prepolymer SFPU-1. 4,4'-Bis(dimethylhydroxysilyl)diphenyl ether (3.19 g) dissolved in 9.0 ml of N,N-dimethylformamide and 4,4'-dihydroxydiphenyl disulfide (2.19 g) dissolved in 6.5 ml of N,N-dimethylformamide were added in sequence, and the reaction was carried out at 40 °C for 1 h to obtain a viscous and transparent prepolymer SFPU-2. The preparation of the subsequent self-healing fluorosilicon superhydrophobic coating material was the same as that in Example 1.

[0062] To verify the self-healing performance of the self-healing superhydrophobic coating, after fixing the scratch length, it was placed under heating or different light conditions. The experiment found that the self-healing superhydrophobic coating layer could complete self-healing in 63 min under heating at 60 °C; the self-healing superhydrophobic coating could not achieve self-healing under ultraviolet light illumination. The water contact angle of the coating was measured using a JC2000D1 type contact angle measuring instrument, and the results are shown in Table 1.

[0063] Example 9

[0064] 1.2 g of difunctional hexafluoroglutaric acid was added to 20 g of polycaprolactone diol (Mn = 2000). Nitrogen was passed through for 10 min to remove the air in the system. Then, it was heated and stirred under nitrogen protection to obtain a colorless and transparent fluorinated polyol. 20 g of the hydroxyl-terminated fluorinated polyol, which was placed in a vacuum drying oven at 120 °C for vacuum drying for 2 h and dissolved in 30 ml of N,N-dimethylformamide, was added to a 100 ml three-necked flask that had been dried in a blast drying oven and treated with nitrogen. 5.5 g of hexamethylene diisocyanate was added, and 0.028 g of dibutyltin dilaurate catalyst was added. The reaction was carried out with stirring at 40 °C for 2 h to obtain a viscous and transparent fluorinated polyisocyanate prepolymer SFPU-1. 4,4'-Bis(dimethylhydroxysilyl)diphenyl ether (3.19 g) dissolved in 9.0 ml of N,N-dimethylformamide and L-cysteine (2.40 g) dissolved in 6.5 ml of N,N-dimethylformamide were added in sequence. The reaction was carried out at 40 °C for 1 h to obtain a viscous and transparent prepolymer SFPU-2. Then, 3-(acryloyloxy)-2-hydroxypropyl methacrylate (4.29 g) dissolved in 5.0 ml of N,N-dimethylformamide was added, and the reaction was carried out at 40 °C for 1 h to obtain a viscous, transparent, and light yellow fluorosilicon polyurethane SFPU-3. The preparation of the subsequent self-healing fluorosilicon superhydrophobic coating material was the same as that in Example 1.

[0065] To verify the self-healing performance of the self-healing superhydrophobic coating, after fixing the scratch length, it was placed under heating or different light conditions. The experiment found that the self-healing superhydrophobic coating could complete self-healing in 67 min under heating at 60 °C; under ultraviolet light irradiation, the self-healing superhydrophobic coating could not achieve self-healing; the water contact angle of the coating was tested using a JC2000D1 type contact angle measuring instrument, and the results are shown in Table 1.

[0066] Example 10

[0067] 1.2 g of difunctional hexafluoroglutaric acid was added to 20 g of polycaprolactone diol (Mn = 2000). Nitrogen was passed through for 10 min to remove the air in the system, and then it was heated and stirred under nitrogen protection to obtain a colorless and transparent fluorinated polyol. 20 g of the hydroxyl-terminated fluorinated polyol, which was placed in a vacuum drying oven at 120 °C for vacuum drying for 2 h and dissolved in 30 ml of N,N-dimethylformamide, was added to a 100 ml three-necked flask dried in a blast drying oven and treated with nitrogen. 5.5 g of hexamethylene diisocyanate was added, and 0.028 g of dibutyltin dilaurate catalyst was added. The reaction was carried out with stirring at 40 °C for 2 h to obtain a viscous and transparent fluorinated polyisocyanate prepolymer SFPU-1. 4,4'-Bis(dimethylhydroxysilyl)diphenyl ether (3.19 g) dissolved in 9.0 ml of N,N-dimethylformamide and L-cysteine (2.40 g) dissolved in 6.5 ml of N,N-dimethylformamide were added successively, and the reaction was carried out at 40 °C for 1 h to obtain a viscous and transparent prepolymer SFPU-2. Then, 2-hydroxypropyl methacrylate (2.89 g) dissolved in 5.0 ml of N,N-dimethylformamide was added, and the reaction was carried out at 40 °C for 1 h to obtain a viscous, transparent and light yellow fluorosilicone polyurethane SFPU-3. The preparation of the subsequent self-healing fluorosilicone superhydrophobic coating material was the same as that in Example 1.

[0068] To verify the self-healing performance of the self-healing superhydrophobic coating, after fixing the scratch length, it was placed under heating or different light conditions. The experiment found that the self-healing superhydrophobic coating could complete self-healing in 69 min under heating at 60 °C; the self-healing superhydrophobic coating could not achieve self-healing under ultraviolet light irradiation; the water contact angle of the coating was measured using a JC2000D1 type contact angle measuring instrument, and the results are shown in Table 1.

[0069] Example 11

[0070] 1.2 g of bifunctional hexafluoroglutaric acid was added to 20 g of polycaprolactone diol (Mn = 2000). Nitrogen was passed through for 10 min to remove the air in the system, and then it was heated and stirred under nitrogen protection to obtain a colorless and transparent fluorinated polyol. 20 g of the hydroxyl-terminated fluorinated polyol, which was placed in a vacuum drying oven at 120 °C for vacuum drying for 2 h and dissolved in 30 ml of N,N-dimethylformamide, was added to a 100 ml three-necked flask that had been dried in a blast drying oven and treated with nitrogen. 5.5 g of hexamethylene diisocyanate was added, and 0.028 g of dibutyltin dilaurate catalyst was added. The reaction was carried out with stirring at 40 °C for 2 h to obtain a viscous and transparent fluorinated polyisocyanate prepolymer SFPU-1. 4,4'-Bis(dimethylhydroxysilyl)diphenyl ether (3.19 g) dissolved in 9.0 ml of N,N-dimethylformamide and L-cysteine (2.40 g) dissolved in 6.5 ml of N,N-dimethylformamide were added in sequence, and the reaction was carried out at 40 °C for 1 h to obtain a viscous and transparent prepolymer SFPU-2. Then 2-aminoethyl methacrylate (3.32 g) dissolved in 5.0 ml of N,N-dimethylformamide was added, and the reaction was carried out at 40 °C for 1 h to obtain a viscous, transparent and light yellow fluorosilicon polyurethane SFPU-3. The preparation of the subsequent self-healing fluorosilicon superhydrophobic coating material was the same as in Example 1.

[0071] To verify the self-healing performance of the self-healing superhydrophobic coating, after fixing the scratch length, it was placed under heating or different light conditions. The experiment found that the self-healing superhydrophobic coating could complete self-healing in 61 min under heating at 60 °C; under ultraviolet light illumination, the self-healing superhydrophobic coating could not achieve self-healing; the water contact angle of the coating was tested using a JC2000D1 type contact angle measuring instrument, and the results are shown in Table 1.

[0072] Example 12

[0073] 1.2 g of difunctional hexafluoroglutaric acid was added to 20 g of polycaprolactone diol (Mn = 2000). Nitrogen was passed through for 10 min to remove the air in the system, and then it was heated and stirred under nitrogen protection to obtain a colorless and transparent fluorinated polyol. 20 g of the hydroxyl-terminated fluorinated polyol, which was placed in a vacuum drying oven at 120 °C for 2 h and dissolved in 30 ml of N,N-dimethylformamide, was added to a 100 ml three-necked flask that had been dried in a blast drying oven and treated with nitrogen. 5.5 g of hexamethylene diisocyanate was added, and 0.028 g of dibutyltin dilaurate catalyst was added. The reaction was carried out with stirring at 40 °C for 2 h to obtain a viscous and transparent fluorinated polyisocyanate prepolymer SFPU-1. 4,4'-Bis(dimethylhydroxysilyl)diphenyl ether (3.19 g) dissolved in 9.0 ml of N,N-dimethylformamide and L-cysteine (2.40 g) dissolved in 6.5 ml of N,N-dimethylformamide were added in sequence, and the reaction was carried out at 40 °C for 1 h to obtain a viscous and transparent prepolymer SFPU-2. Then 4-methylumbelliferone (3.52 g) dissolved in 5.0 ml of N,N-dimethylformamide was added, and the reaction was carried out at 40 °C for 1 h to obtain a viscous, transparent and light yellow fluorosilicon polyurethane SFPU-3. 25 g of hydrophobic nano-zinc oxide powder was weighed. The zinc oxide was added to 30 ml of anhydrous ethanol with a purity ≥99.7%, and magnetic stirring was carried out for 1 h. Then it was ultrasonically dispersed in an ultrasonic cleaner with a frequency of 40 KHz at room temperature for 30 min. Finally, it was dried and ground at 100 °C. The treated zinc oxide (20 g) and silane coupling agent KH550 (0.4 g) were added to the reaction system at the same time, and the reaction was carried out with stirring at 40 °C for 2 h to obtain a viscous self-healing fluorosilicon polyurethane SFPU-4 containing nano-fillers. The viscous self-healing fluorosilicon polyurethane SFPU-4 containing nano-fillers was slowly poured into a mold and irradiated with UV light for 10 min to obtain a self-healing fluorosilicon superhydrophobic coating material.

[0074] To verify the self-healing performance of the self-healing superhydrophobic coating, after fixing the scratch length, it was placed under heating or different light conditions. The experiment found that the self-healing superhydrophobic coating could complete self-healing in 62 min under heating at 60 °C; under ultraviolet light irradiation, the self-healing superhydrophobic coating could not achieve self-healing; the water contact angle of the coating was tested using a JC2000D1 type contact angle measuring instrument, and the results are shown in Table 1.

[0075] Example 13

[0076] 1.2 g of difunctional hexafluoroglutaric acid was added to 20 g of polycaprolactone diol (Mn = 2000). Nitrogen was passed through for 10 min to remove the air in the system. Then, it was heated and stirred under nitrogen protection to obtain a colorless and transparent fluorinated polyol. 20 g of the hydroxyl-terminated fluorinated polyol, which was placed in a vacuum drying oven at 120 °C for vacuum drying for 2 h and dissolved in 30 ml of N,N-dimethylformamide, was added to a 100 ml three-necked flask that had been dried in a blast drying oven and treated with nitrogen. 5.5 g of hexamethylene diisocyanate was added, and 0.028 g of dibutyltin dilaurate catalyst was added. The reaction was carried out with stirring at 40 °C for 2 h to obtain a viscous and transparent fluorinated polyisocyanate prepolymer SFPU-1. 4,4'-Bis(dimethylhydroxysilyl)diphenyl ether (3.19 g) dissolved in 9.0 ml of N,N-dimethylformamide and L-cysteine (2.40 g) dissolved in 6.5 ml of N,N-dimethylformamide were added in sequence, and the reaction was carried out at 40 °C for 1 h to obtain a viscous and transparent prepolymer SFPU-2. Then, 4-methylumbelliferone (3.52 g) dissolved in 5.0 ml of N,N-dimethylformamide was added, and the reaction was carried out at 40 °C for 1 h to obtain a viscous, transparent, and light yellow fluorosilicon polyurethane SFPU-3. 25 g of hydrophobic nano-titanium dioxide powder was weighed. The titanium dioxide was added to 30 ml of anhydrous ethanol with a purity of ≥99.7%, and magnetic stirring was carried out for 1 h. Then, it was ultrasonically dispersed in an ultrasonic cleaner at a frequency of 40 KHz at room temperature for 30 min. Finally, it was dried and ground at 100 °C. The treated titanium dioxide (20 g) and silane coupling agent KH550 (0.4 g) were simultaneously added to the reaction system, and the stirring was carried out at 40 °C for 2 h to obtain a viscous self-healing fluorosilicon polyurethane SFPU-4 containing nano-fillers. The viscous self-healing fluorosilicon polyurethane SFPU-4 containing nano-fillers was slowly poured into a mold, and UV light was irradiated for 10 min to obtain a self-healing fluorosilicon superhydrophobic coating material.

[0077] To verify the self-healing performance of the self-healing superhydrophobic coating, after fixing the scratch length, it was placed under heating or different light conditions. The experiment found that the self-healing superhydrophobic coating could complete self-healing in 68 min under heating at 60 °C; the self-healing superhydrophobic coating could not achieve self-healing under ultraviolet light irradiation. The water contact angle of the coating was tested using a JC2000D1 type contact angle measuring instrument, and the results are shown in Table 1.

[0078] Example 14

[0079] 1.2 g of bifunctional hexafluoroglutaric acid was added to 20 g of polycaprolactone diol (Mn = 2000). Nitrogen was passed through for 10 min to remove the air in the system. Then, it was heated and stirred under nitrogen protection to obtain a colorless and transparent fluorinated polyol. 20 g of the hydroxyl-terminated fluorinated polyol, which was placed in a vacuum drying oven at 120 °C for vacuum drying for 2 h and dissolved in 30 ml of N,N-dimethylformamide, was added to a 100 ml three-necked flask that had been dried in a blast drying oven and treated with nitrogen. 5.5 g of hexamethylene diisocyanate was added, and 0.028 g of dibutyltin dilaurate catalyst was added. The reaction was carried out with stirring at 40 °C for 2 h to obtain a viscous and transparent fluorinated polyisocyanate prepolymer SFPU-1. 4,4'-Bis(dimethylhydroxysilyl)diphenyl ether (3.19 g) dissolved in 9.0 ml of N,N-dimethylformamide and L-cysteine (2.40 g) dissolved in 6.5 ml of N,N-dimethylformamide were added successively, and the reaction was carried out at 40 °C for 1 h to obtain a viscous and transparent prepolymer SFPU-2. Then, 4-methylumbelliferone (3.52 g) dissolved in 5.0 ml of N,N-dimethylformamide was added, and the reaction was carried out at 40 °C for 1 h to obtain a viscous, transparent, and light yellow fluorosilicon polyurethane SFPU-3. 25 g of hydrophobic nano-aluminum oxide powder was weighed. The aluminum oxide was added to 30 ml of anhydrous ethanol with a purity ≥99.7%, and magnetic stirring was carried out for 1 h. Then, it was ultrasonically dispersed in an ultrasonic cleaner at a frequency of 40 KHz at room temperature for 30 min. Finally, it was dried and ground at 100 °C. 20 g of the treated aluminum oxide and 0.4 g of silane coupling agent KH550 were added to the reaction system simultaneously, and the reaction was carried out with stirring at 40 °C for 2 h to obtain a viscous self-healing fluorosilicon polyurethane SFPU-4 containing nano-fillers. The viscous self-healing fluorosilicon polyurethane SFPU-4 containing nano-fillers was slowly poured into a mold, and UV light was irradiated for 10 min to obtain a self-healing fluorosilicon superhydrophobic coating material.

[0080] To verify the self-healing performance of the self-healing superhydrophobic coating, after fixing the scratch length, it was placed under heating or different light conditions. The experiment found that the self-healing superhydrophobic coating could complete self-healing in 64 min under heating at 60 °C; the self-healing superhydrophobic coating could not achieve self-healing under ultraviolet light irradiation; the water contact angle of the coating was tested using a JC2000D1 type contact angle measuring instrument, and the results are shown in Table 1.

[0081] Example 15

[0082] 1.2 g of bifunctional hexafluoroglutaric acid was added to 20 g of polycaprolactone diol (Mn = 2000). Nitrogen was passed through for 10 min to remove the air in the system. Then, it was heated and stirred under nitrogen protection to obtain a colorless and transparent fluorinated polyol. 20 g of the hydroxyl-terminated fluorinated polyol, which was placed in a vacuum drying oven at 120 °C for vacuum drying for 2 h and dissolved in 30 ml of N,N-dimethylformamide, was added to a 100 ml three-necked flask that had been dried in a blast drying oven and treated with nitrogen. 5.5 g of hexamethylene diisocyanate and 0.028 g of dibutyltin dilaurate catalyst were added. The reaction was carried out with stirring at 40 °C for 2 h to obtain a viscous and transparent fluorinated polyisocyanate prepolymer SFPU-1. 4,4'-Bis(dimethylhydroxysilyl)diphenyl ether (3.19 g) dissolved in 9.0 ml of N,N-dimethylformamide and L-cysteine (2.40 g) dissolved in 6.5 ml of N,N-dimethylformamide were added successively. The reaction was carried out at 40 °C for 1 h to obtain a viscous and transparent prepolymer SFPU-2. Then, 4-methylumbelliferone (3.52 g) dissolved in 5.0 ml of N,N-dimethylformamide was added, and the reaction was carried out at 40 °C for 1 h to obtain a viscous, transparent, and light yellow fluorosilicon polyurethane SFPU-3. 25 g of hydrophobic nano-silica powder was weighed. The silica was added to 30 ml of anhydrous ethanol with a purity ≥99.7%. It was magnetically stirred for 1 h, then ultrasonically dispersed in an ultrasonic cleaner at a frequency of 40 KHz at room temperature for 30 min. Finally, it was dried and ground at 100 °C. The treated silica (20 g) and silane coupling agent A151 (0.4 g) were simultaneously added to the reaction system, and the mixture was stirred at 40 °C for 2 h to obtain a viscous self-healing fluorosilicon polyurethane SFPU-4 containing nano-fillers. The viscous self-healing fluorosilicon polyurethane SFPU-4 containing nano-fillers was slowly poured into a mold and irradiated with UV light for 10 min to obtain a self-healing fluorosilicon superhydrophobic coating material.

[0083] To verify the self-healing performance of the self-healing superhydrophobic coating, after fixing the scratch length, it was placed under heating or different lighting conditions. The experiment found that the self-healing superhydrophobic coating could complete self-healing in 67 min under heating at 60 °C; under ultraviolet light irradiation, the self-healing superhydrophobic coating could not achieve self-healing; the water contact angle of the coating was tested using a JC2000D1 type contact angle measuring instrument, and the results are shown in Table 1.

[0084] Control Example 1

[0085] 1.2 g of difunctional hexafluoroglutaric acid was added to 20 g of polycaprolactone diol (Mn = 2000). Nitrogen was passed through for 10 min to remove the air in the system, and then it was heated and stirred under nitrogen protection to obtain a colorless and transparent fluorinated polyol. 20 g of the hydroxyl-terminated fluorinated polyol, which was placed in a vacuum drying oven at 120 °C for vacuum drying for 2 h and dissolved in 30 ml of N,N-dimethylformamide, was added to a 100 ml three-necked flask that had been dried in a blast drying oven and treated with nitrogen. 5.5 g of hexamethylene diisocyanate was added, and 0.028 g of dibutyltin dilaurate catalyst was added. The reaction was carried out with stirring at 40 °C for 2 h to obtain a viscous and transparent fluorinated polyisocyanate prepolymer SFPU-1. 4,4'-Bis(dimethylhydroxysilyl)diphenyl ether (3.19 g) dissolved in 9.0 ml of N,N-dimethylformamide and L-cysteine (2.40 g) dissolved in 6.5 ml of N,N-dimethylformamide were added successively, and the reaction was carried out at 40 °C for 1 h to obtain a viscous and transparent prepolymer SFPU-2. 25 g of hydrophobic nano-silica powder was weighed. The silica was added to 30 ml of anhydrous ethanol with a purity ≥99.7%, and magnetically stirred for 1 h. Then it was ultrasonically dispersed in an ultrasonic cleaner at a frequency of 40 KHz at room temperature for 30 min. Finally, it was dried and ground at 100 °C. 20 g of the treated silica and 0.4 g of silane coupling agent KH550 were added to the reaction system simultaneously, and the reaction was carried out with stirring at 40 °C for 2 h to obtain a viscous self-healing fluorosilicone polyurethane SFPU-4 containing nano-fillers. The viscous self-healing fluorosilicone polyurethane SFPU-4 containing nano-fillers was slowly poured into a mold and irradiated with UV light for 10 min, and a self-healing fluorosilicone superhydrophobic coating material could not be obtained.

[0086] Comparative Example 2

[0087] 1.2 g of bifunctional hexafluoroglutaric acid was added to 20 g of polycaprolactone diol (Mn = 2000). Nitrogen was passed through for 10 min to remove the air in the system, and then it was heated and stirred under nitrogen protection to obtain a colorless and transparent fluorinated polyol. 20 g of the hydroxyl-terminated fluorinated polyol, which was placed in a vacuum drying oven at 120 °C for vacuum drying for 2 h and dissolved in 30 ml of N,N-dimethylformamide, was added to a 100 ml three-necked flask that had been dried in a blast drying oven and treated with nitrogen. 5.5 g of hexamethylene diisocyanate was added, and 0.028 g of dibutyltin dilaurate catalyst was added. The reaction was carried out with stirring at 40 °C for 2 h to obtain a viscous and transparent fluorinated polyisocyanate prepolymer SFPU-1. L-cysteine (2.40 g) dissolved in 6.5 ml of N,N-dimethylformamide was added, and the reaction was carried out at 40 °C for 1 h to obtain a viscous and transparent prepolymer SFPU-2. Then, 4-methylumbelliferone (3.52 g) dissolved in 5.0 ml of N,N-dimethylformamide was added, and the reaction was carried out at 40 °C for 1 h to obtain a viscous, transparent and light yellow fluorosilicon polyurethane SFPU-3. 25 g of hydrophobic nano-silica powder was weighed. The silica was added to 30 ml of anhydrous ethanol with a purity ≥99.7%, and magnetic stirring was carried out for 1 h. Then, it was ultrasonically dispersed in a ultrasonic cleaner with a frequency of 40 KHz at room temperature for 30 min. Finally, it was dried and ground at 100 °C. 20 g of the treated silica and 0.4 g of silane coupling agent KH550 were added to the reaction system simultaneously, and the stirring was carried out at 40 °C for 2 h to obtain a viscous self-healing fluorosilicon polyurethane SFPU-4 containing nano-fillers. The viscous self-healing fluorosilicon polyurethane SFPU-4 containing nano-fillers was slowly poured into a mold and irradiated with UV light for 10 min to obtain a self-healing fluorosilicon superhydrophobic coating material.

[0088] To verify the self-healing performance of the self-healing superhydrophobic coating, after fixing the scratch length, it was placed under heating or different light conditions. The experiment found that the self-healing superhydrophobic coating could not self-heal within 90 min under heating at 60 °C; the self-healing superhydrophobic coating could not achieve self-healing under ultraviolet light irradiation. The water contact angle of the coating was tested using a JC2000D1 type contact angle measuring instrument, and the results are shown in Table 1.

[0089] Control Example 3

[0090] 1.2 g of bifunctional hexafluoroglutaric acid was added to 20 g of polycaprolactone diol (Mn = 2000). Nitrogen was passed through for 10 min to remove the air in the system, and then it was heated and stirred under nitrogen protection to obtain a colorless and transparent fluorinated polyol. 20 g of the hydroxyl-terminated fluorinated polyol, which was placed in a vacuum drying oven at 120 °C for vacuum drying for 2 h and dissolved in 30 ml of N,N-dimethylformamide, was added to a 100 ml three-necked flask that had been dried in a blast drying oven and treated with nitrogen. 5.5 g of hexamethylene diisocyanate was added, and 0.028 g of dibutyltin dilaurate catalyst was added. The reaction was carried out with stirring at 40 °C for 2 h to obtain a viscous and transparent fluorinated polyisocyanate prepolymer SFPU-1. 4,4'-Bis(dimethylhydroxysilyl)diphenyl ether (3.19 g) dissolved in 9.0 ml of N,N-dimethylformamide and L-cysteine (2.40 g) dissolved in 6.5 ml of N,N-dimethylformamide were added in sequence, and the reaction was carried out at 40 °C for 1 h to obtain a viscous and transparent prepolymer SFPU-2. Then, 4-methylumbelliferone (3.52 g) dissolved in 5.0 ml of N,N-dimethylformamide was added, and the reaction was carried out at 40 °C for 1 h to obtain a viscous, transparent, and light yellow fluorosilicon polyurethane SFPU-3. The viscous, transparent, and light yellow fluorosilicon polyurethane SFPU-3 was slowly poured into a mold and irradiated with UV light for 10 min to obtain a self-healing fluorosilicon superhydrophobic coating material.

[0091] To verify the self-healing performance of the self-healing superhydrophobic coating, after fixing the scratch length, it was placed under heating or different light conditions. The experiment found that the self-healing superhydrophobic coating could complete self-healing in 55 min under heating at 60 °C; the self-healing superhydrophobic coating could not achieve self-healing under ultraviolet light irradiation; the water contact angle of the coating was measured using a JC2000D1 type contact angle measuring instrument, and the results are shown in Table 1.

[0092] Table 1 shows the comparison of the water contact angles of the coating in different environments

[0093]

[0094]

Claims

1. A photocurable self-healing fluorosilicon superhydrophobic coating, characterized in that: The structural general formula of the coating material is as follows: R 5 -OOCHN-R 4 -OOCHN-R 3 -OOCHN-R 2 -OOCHN-R 1 —OOC-R-COO-R 1 -NHCOO-R 2 -NHCOO-R 3 -NHCOO-R 4 -NHCOO-R 5 Among them, -NHCOO- can be replaced by -NHCONH-.

2. A preparation method of the photocurable self-healing fluorosilicon superhydrophobic coating according to claim 1, characterized in that: The preparation method steps are as follows: (1) Add polyol to the bifunctional fluorinated carboxylic acid monomer, pass nitrogen for 10 min to remove the air in the system, and then heat and stir under nitrogen protection to obtain a colorless and transparent fluorinated polyol; The bifunctional fluorinated carboxylic acid monomer is one of 2,2-bis(4-carboxyphenyl)hexafluoropropane, hexafluoroglutaric acid, perfluorosebacic acid, perfluorooctanedioic acid or 2,2-difluoroglutaric acid; The polyol is one of polytetrahydrofuran ether diol, polypropylene glycol, polyethylene glycol, polylactic acid or polycaprolactone diol; The molar ratio of polyol to bifunctional fluorinated carboxylic acid monomer is 2:1; (2) Place the fluorinated polyol in a vacuum drying oven, vacuum dry at 120 °C for 2 h, add isocyanate and organotin catalyst to it, fully dissolve with an organic solvent, and stir at 30-40 °C for 2 h to obtain a viscous and transparent fluorinated polyisocyanate prepolymer SFPU-1; The isocyanate is one of isophorone diisocyanate, 2,4-toluene diisocyanate, diphenylmethane diisocyanate, dicyclohexylmethane diisocyanate or hexamethylene diisocyanate; The molar ratio of isocyanate to bifunctional fluorinated polyol is 3∶1; (3) Sequentially add a small molecule chain extender containing silicon and having a dihydroxy or amino structure and a small molecule chain extender containing a disulfide bond and having a dihydroxy or amino structure dissolved in an organic solvent to the prepolymer SFPU-1, and keep the system at 30-40 °C for a chain extension reaction for 1 h to obtain a viscous and transparent prepolymer SFPU-2; The small molecule chain extender containing silicon and having a dihydroxy or amino structure is 4,4'-bis(dimethylhydroxysilyl)diphenyl ether, diphenylsilanediol, bis(tert-butylamino)silane, 3-[2-(2-aminoethylamino)ethylamino]propyl-trimethoxysilane, aminoethylaminoisobutylmethyldimethoxysilane; The small molecule chain extender containing a disulfide bond and having a dihydroxy or amino structure is one of cystine, 4,4'-diaminodiphenyl disulfide, 4,4'-dihydroxydiphenyl disulfide; The molar ratio of the small molecule chain extender containing silicon and having a dihydroxy or amino structure and the small molecule chain extender containing a disulfide bond and having a dihydroxy or amino structure to the bifunctional fluorinated polyisocyanate prepolymer is 1∶1∶1; (4) Add a capping agent containing an electron-withdrawing group adjacent to a double bond structure and having an amino or hydroxy group dissolved in an organic solvent to SFPU-2, and the system undergoes a capping reaction at 30-40 °C for 1 h to obtain a viscous, transparent and light yellow fluorosilicon polyurethane SFPU-3; The end-capping agent containing an electron-withdrawing group adjacent to a double bond structure and having an amino group or a hydroxyl group is 4-methylumbelliferone, 3-(acryloyloxy)-2-hydroxypropyl methacrylate, hydroxypropyl methacrylate, 2-(tert-butylamino)ethyl methacrylate or 2-aminoethyl methacrylate. The molar ratio of the end-capping agent containing an acrylate structure and having an amino group or a hydroxyl group to the bifunctional fluorinated polyisocyanate prepolymer is 2:1; (5) Add the nano filler to absolute ethanol, stir well for dispersion, and perform ultrasonic treatment for 1-2 h. Then add it to SFPU-3 together with the silane coupling agent. The system is stirred at 30-40 °C for 2 h to obtain a viscous self-healing fluorosilicone polyurethane SFPU-4 containing nano fillers; The addition amount of the silane coupling agent is 0.5-2 wt% of the mass of the nano filler, and the dosage of the nano filler is 0.5-2 times the mass of the fluorosilicone polyurethane; (6) Pour the viscous self-healing fluorinated polyurethane SFPU-4 containing nano fillers into a mold and irradiate it with UV light for 10 min to obtain a self-healing fluorosilicone superhydrophobic coating material.

3. The preparation method of the photocurable self-healing fluorosilicone superhydrophobic coating according to claim 2: The organic solvent described in steps (2)-(4) is one of N,N-dimethylformamide, acetone, ethyl acetate, butyl acetate, toluene, xylene, dichloromethane or tetrahydrofuran.

4. The preparation method of the photocurable self-healing fluorosilicone superhydrophobic coating according to claim 2, characterized in that: The silane coupling agent described in step (5) is one or more of γ-aminopropyltriethoxysilane, γ-(2,3-epoxypropoxy)propyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, γ-mercaptopropyltrimethoxysilane, N-(β-aminoethyl)-γ-aminopropylmethyldimethoxysilane, n-octyltriethoxysilane, 3-(trimethoxysilyl)-1-propylamine, vinyltriethoxysilane, vinyltriethoxysilane, vinylsilane, vinyltris(β-methoxyethoxy)silane; The nano filler is one of nano silica, nano zinc oxide, nano titanium dioxide, nano aluminum oxide.

5. The application of a photocurable self-healing fluorosilicone superhydrophobic coating according to claim 1, characterized in that: The coating is applied to the field of anti-icing of aircraft in aerospace.

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