A building anti-leakage repair material and a preparation method thereof

Abstract

The application discloses a kind of building anti-leakage repair material and preparation method thereof, it is related to building material technical field.The application is prepared when building anti-leakage repair material, 1-vinyl imidazole and 3-mercapto-1,2-propanediol addition reaction, then with 3-chloropropyl trimethoxysilane quaternization reaction, antibacterial monomer is prepared;Polyurethane prepolymer is chain-extended with dimethylol propionic acid and antibacterial monomer, then deionized water is emulsified, and water-based polyurethane emulsion is prepared;Self-repairing crosslinking agent and water-based polyurethane emulsion are reacted to prepare functional water-based polyurethane emulsion;Water, functional water-based polyurethane emulsion, water-reducing agent, defoaming agent are mixed, mixed dry material is added and stirred to prepare building anti-leakage repair material.The building anti-leakage repair material prepared by the application has excellent anti-seepage, antibacterial and mildew-proof, self-repairing performance.

Description

Technical Field

[0001] This invention relates to the field of building materials technology, specifically to a building waterproofing and repair material and its preparation method. Background Technology

[0002] Building leakage is a long-standing and common quality problem in the field of civil engineering. Currently, commonly used building waterproofing materials mainly include traditional cement-based waterproofing materials, asphalt-based waterproof membranes, and synthetic polymer waterproofing coatings such as acrylic esters. Among them, traditional cement-based materials are the most widely used in waterproofing and repair projects due to their advantages such as good compatibility with the substrate, low cost, and convenient construction. However, they also have problems such as insufficient toughness, poor crack resistance, susceptibility to drying shrinkage cracks, and long-term degradation of water resistance and impermeability.

[0003] Waterborne polyurethane, as an environmentally friendly polymer material, possesses excellent flexibility, water resistance, adhesion, and film-forming properties, effectively compensating for the brittleness of traditional cement-based materials. When waterborne polyurethane is compounded with cement-based materials, the polyurethane emulsion can form a continuous polymer network structure within the cement hydration system, filling the pores inside the cement paste, blocking seepage channels, and significantly improving the material's impermeability.

[0004] However, existing research still faces challenges such as insufficient control over the compatibility of polyurethane with cement, complex dynamic cross-linking network construction processes, and the need to improve long-term service performance stability. Therefore, developing high-performance, long-life, and self-healing waterborne polyurethane-modified cement-based waterproofing and repair materials is of significant theoretical and engineering value for solving building leakage problems and promoting the upgrading and iteration of building waterproofing materials. Summary of the Invention

[0005] The purpose of this invention is to provide a building waterproofing repair material and its preparation method to solve the problems existing in the prior art.

[0006] To solve the above-mentioned technical problems, the present invention provides the following solution: A building waterproofing and repair material is prepared by adding 1-vinylimidazol and 3-mercapto-1,2-propanediol, followed by quaternization with 3-chloropropyltrimethoxysilane to obtain an antibacterial monomer; chain-extending a polyurethane prepolymer with dimethylolpropionic acid and the antibacterial monomer, followed by emulsification with deionized water to obtain an aqueous polyurethane emulsion; reacting a self-healing crosslinking agent with the aqueous polyurethane emulsion to obtain a functionalized aqueous polyurethane emulsion; and mixing water, the functionalized aqueous polyurethane emulsion, a water-reducing agent, and an antifoaming agent, then adding the dry mixture and stirring to obtain the final product. The polyurethane prepolymer is prepared by reacting polybutylene adipate diol and isophorone diisocyanate. The self-healing crosslinking agent is prepared by self-condensation of 4-carboxyphenylboronic acid in thionyl chloride. The mixed dry material is prepared by mixing cement, fly ash, and river sand.

[0007] A method for preparing a building waterproofing and repair material, the method comprising the following preparation steps: (1) Mix 3-mercapto-1,2-propanediol, tetrahydrofuran, and azobisisobutyronitrile in a mass ratio of 1:(9~11):(0.008~0.01) until homogeneous. Stir at room temperature for 10~20 min. Add 1-vinylimidazole in equimolar amounts of 3-mercapto-1,2-propanediol. Heat to 55~65℃ and stir for 7~9 h. Add 3-chloropropyltrimethoxysilane and continue stirring for 46~50 h. Remove tetrahydrofuran by rotary evaporation. Pour in 5~7 times the mass of the antibacterial precursor in ethyl acetate to precipitate and filter. Repeat 2~4 times. Dry at 55~65℃ for 22~26 h to obtain the antibacterial monomer. (2) Polybutylene adipate diol and isophorone diisocyanate were prepared into a polyurethane prepolymer; antibacterial monomers were prepared into an antibacterial monomer solution; dimethylolpropionic acid and antibacterial monomer solution were added to the polyurethane prepolymer, the temperature was lowered to 60~70℃, the reaction was stirred for 1.5~2.5h, triethylamine of equimolar amount of dimethylolpropionic acid was added, the temperature was cooled to 30~40℃, the mixture was stirred for 40~50min, deionized water was added to make the solid content 20~30%, the mixture was subjected to high-speed shearing at room temperature for 50~70min, and acetone was removed by rotary evaporation to obtain an aqueous polyurethane emulsion; (3) Mix the self-healing crosslinking agent and the waterborne polyurethane emulsion at a mass ratio of 1:(150~250), and stir and react at 30~40℃ for 50~70 min under nitrogen protection to obtain the functionalized waterborne polyurethane emulsion. (4) By mass, mix 30-40 parts water, 2.5-3.5 parts functionalized waterborne polyurethane emulsion, 0.9-1.1 parts water-reducing agent, and 0.1-0.3 parts defoamer evenly, stir at room temperature for 1-3 minutes, add the mixed dry material, stir for 5-15 minutes, and obtain the building waterproof repair material.

[0008] As an optimization, the amount of 3-chloropropyltrimethoxysilane added in step (1) is 1 to 1.2 times the molar amount of 3-mercapto-1,2-propanediol.

[0009] As an optimization, the molar ratio of polybutylene adipate diol, isophorone diisocyanate, dimethylolpropionic acid and antibacterial monomer in step (2) is 1:(2.1~2.5):(0.8~1):(0.4~0.6).

[0010] As an optimization, the preparation method of the polyurethane prepolymer in step (2) is as follows: polybutylene adipate diol and isophorone diisocyanate are mixed evenly in a molar ratio of 1:(2.1~2.5), and 0.01~0.02 times the mass of polybutylene adipate diol diol dibutyltin dilaurate is added. Under nitrogen protection, the temperature is raised to 75~85℃ and the mixture is stirred for 1~2 hours to obtain the polyurethane prepolymer.

[0011] As an optimization, the method for preparing the antibacterial monomer solution in step (2) is as follows: mix the antibacterial monomer and acetone at a mass ratio of 1:(1.6~2) evenly, stir at room temperature for 5~15 min, and obtain the antibacterial monomer solution.

[0012] As an optimization, the preparation method of the self-healing crosslinking agent in step (3) is as follows: 4-carboxyphenylboronic acid and thionyl chloride are mixed evenly at a mass ratio of 1:(15~17), and under nitrogen protection, the mixture is refluxed and stirred at 75~85℃ for 10~12h. The thionyl chloride is removed by rotary evaporation to obtain the self-healing crosslinking agent.

[0013] As an optimization, the type of water-reducing agent in step (4) is: polycarboxylate water-reducing agent, purchased from Jinan Jianhui Chemical Co., Ltd.; the defoamer is TCX-1 organosilicon defoamer, purchased from Shandong Taide New Materials Co., Ltd.

[0014] As an optimization, the preparation method of the mixed dry material in step (4) is as follows: 80-100 parts of cement, 9-11 parts of fly ash and 140-160 parts of river sand are mixed evenly by mass, and then dry-mixed at room temperature for 2-4 minutes to obtain the mixed dry material.

[0015] As an optimization, the cement is P·O 42.5 grade ordinary Portland cement, purchased from Hunan Xindingli New Material Technology Co., Ltd.; the fly ash is grade I fly ash with a particle size of 400 mesh, purchased from Lingshou County Laipeng Mineral Products Business Department; and the river sand has a particle size of 30 mesh, purchased from Lingshou County Pengxia Furnace Lining Material Processing Plant.

[0016] Compared with the prior art, the beneficial effects achieved by the present invention are: First, 1-vinylimidazolium and 3-mercapto-1,2-propanediol are added together and then quaternized with 3-chloropropyltrimethoxysilane to prepare an antibacterial monomer. The tertiary amine nitrogen atom on the imidazole ring is used to quaternize with 3-chloropropyltrimethoxysilane, introducing a quaternary ammonium salt antibacterial group, thus endowing the building waterproofing and repair material with excellent broad-spectrum antibacterial and antifungal properties. The introduction of the trimethoxysilyl group achieves chemical anchoring with the cement matrix, thereby giving the building waterproofing and repair material excellent interfacial adhesion and waterproofing properties.

[0017] Secondly, a waterborne polyurethane prepolymer is prepared by reacting polybutylene adipate diol and isophorone diisocyanate; the waterborne polyurethane prepolymer is then chain-extended with dimethylolpropionic acid and antibacterial monomers, and then emulsified with deionized water to obtain a waterborne polyurethane emulsion; hydrophilic carboxyl groups are introduced into the polyurethane main chain to give it self-emulsifying ability, which can be stably dispersed in cement-based systems. After film formation, it can fill the pores of the matrix and block the seepage channels, giving the building waterproofing and repair material excellent waterproofing and antibacterial properties.

[0018] Finally, a trifunctional self-healing crosslinking agent with a dynamic triboroxane structure was prepared by self-condensation of 4-carboxyphenylboronic acid in thionyl chloride. The self-healing crosslinking agent was reacted with an aqueous polyurethane emulsion to prepare a functionalized aqueous polyurethane emulsion. Dynamic borate ester bonds were covalently grafted into the polyurethane molecular chain to construct a three-dimensional dynamic crosslinking network. Self-healing of cracks was achieved through reversible breakage and reconstruction of borate ester bonds, which improved the mechanical strength and water resistance of the polyurethane cement-based material after compounding, thereby further improving the seepage prevention performance of the building waterproofing and repair material. Detailed Implementation

[0019] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0020] Example 1: A method for preparing a building waterproofing and repair material, the method comprising the following steps: (1) Mix 3-mercapto-1,2-propanediol, tetrahydrofuran, and azobisisobutyronitrile in a mass ratio of 1:9:0.008 until homogeneous. Stir at room temperature for 20 min. Add 1-vinylimidazole in equimolar amounts of 3-mercapto-1,2-propanediol. Heat to 55 °C and stir for 9 h. Add 3-chloropropyltrimethoxysilane in several molar amounts of 3-mercapto-1,2-propanediol. Continue stirring for 50 h. Remove tetrahydrofuran by rotary evaporation. Pour in ethyl acetate in 5 times the mass of the antibacterial precursor to precipitate. Filter. Repeat twice. Dry at 55 °C for 26 h to obtain the antibacterial monomer. (2) Weigh out polybutylene adipate diol, isophorone diisocyanate, dimethylolpropionic acid and antibacterial monomer in a molar ratio of 1:2.1:0.8:0.4; mix the antibacterial monomer and acetone in a mass ratio of 1:1.6 and stir for 15 min at room temperature to obtain an antibacterial monomer solution; mix polybutylene adipate diol and isophorone diisocyanate evenly, and add 0.01 times the mass of polybutylene adipate diol dibutyl dilaurate. Tin was heated to 75°C under nitrogen protection and stirred for 2 hours to obtain a polyurethane prepolymer. Dimethylolpropionic acid and an antibacterial monomer solution were added to the polyurethane prepolymer, the temperature was lowered to 60°C, and the mixture was stirred for 2.5 hours. An equimolar amount of triethylamine was added to the polyurethane prepolymer, the mixture was cooled to 30°C, stirred for 50 minutes, and deionized water was added to make the solid content 20%. The mixture was subjected to high-speed shearing at room temperature for 70 minutes, and acetone was removed by rotary evaporation to obtain an aqueous polyurethane emulsion. (3) Mix 4-carboxyphenylboronic acid and thionyl chloride at a mass ratio of 1:15, and reflux and stir at 75°C for 12 h under nitrogen protection. Remove thionyl chloride by rotary evaporation to obtain a self-healing crosslinking agent. Mix the self-healing crosslinking agent and waterborne polyurethane emulsion at a mass ratio of 1:150, and stir and react at 30°C for 70 min under nitrogen protection to obtain a functionalized waterborne polyurethane emulsion. (4) Mix 80 parts cement, 9 parts fly ash and 140 parts river sand evenly by weight, and dry mix at room temperature for 4 minutes to obtain a mixed dry material; mix 30 parts water, 2.5 parts functionalized waterborne polyurethane emulsion, 0.9 parts water-reducing agent and 0.1 parts defoamer evenly, stir at room temperature for 3 minutes, add the mixed dry material, and stir for 15 minutes to obtain a building waterproof repair material.

[0021] Example 2: A method for preparing a building waterproofing and repair material, the method comprising the following steps: (1) Mix 3-mercapto-1,2-propanediol, tetrahydrofuran, and azobisisobutyronitrile in a mass ratio of 1:10:0.009 until homogeneous. Stir at room temperature for 15 min. Add 1-vinylimidazole in equimolar amounts of 3-mercapto-1,2-propanediol. Heat to 60 °C and stir for 8 h. Add 3-chloropropyltrimethoxysilane in 1.1 times the molar amount of 3-mercapto-1,2-propanediol. Continue stirring for 48 h. Remove tetrahydrofuran by rotary evaporation. Pour in ethyl acetate in 6 times the mass of the antibacterial precursor to precipitate. Filter. Repeat 3 times. Dry at 60 °C for 24 h to obtain the antibacterial monomer. (2) Weigh out polybutylene adipate diol, isophorone diisocyanate, dimethylolpropionic acid and antibacterial monomer in a molar ratio of 1:2.3:0.9:0.5; mix the antibacterial monomer and acetone in a mass ratio of 1:1.8 and stir for 10 min at room temperature to obtain an antibacterial monomer solution; mix polybutylene adipate diol and isophorone diisocyanate evenly, and add 0.015 times the mass of polybutylene adipate diol dibutyl dilaurate. Tin was heated to 80°C under nitrogen protection and stirred for 1.5 h to obtain a polyurethane prepolymer. Dimethylolpropionic acid and an antibacterial monomer solution were added to the polyurethane prepolymer, the temperature was lowered to 65°C, and the reaction was stirred for 2 h. An equimolar amount of triethylamine was added to dimethylolpropionic acid, the mixture was cooled to 35°C, stirred for 45 min, and deionized water was added to make the solid content 25%. The mixture was subjected to high-speed shearing at room temperature for 60 min, and acetone was removed by rotary evaporation to obtain an aqueous polyurethane emulsion. (3) 4-Carboxyphenylboronic acid and thionyl chloride are mixed evenly at a mass ratio of 1:16. Under nitrogen protection, the mixture is refluxed and stirred at 80°C for 11 h. The thionyl chloride is removed by rotary evaporation to obtain a self-healing crosslinking agent. The self-healing crosslinking agent and waterborne polyurethane emulsion are mixed evenly at a mass ratio of 1:200. Under nitrogen protection, the mixture is stirred and stirred at 35°C for 60 min to obtain a functionalized waterborne polyurethane emulsion. (4) Mix 90 parts cement, 10 parts fly ash and 150 parts river sand evenly by weight, and dry mix at room temperature for 3 minutes to obtain mixed dry material; mix 35 parts water, 3 parts functionalized waterborne polyurethane emulsion, 1 part water-reducing agent and 0.2 parts defoamer evenly, stir at room temperature for 2 minutes, add mixed dry material, stir for 10 minutes to obtain building waterproof repair material.

[0022] Example 3: A method for preparing a building waterproofing and repair material, the method comprising the following steps: (1) Mix 3-mercapto-1,2-propanediol, tetrahydrofuran, and azobisisobutyronitrile in a mass ratio of 1:11:0.01 until homogeneous. Stir at room temperature for 10 min. Add 1-vinylimidazole in equimolar amounts of 3-mercapto-1,2-propanediol. Heat to 65 °C and stir for 7 h. Add 3-chloropropyltrimethoxysilane in 1.2 times the molar amount of 3-mercapto-1,2-propanediol. Continue stirring for 46 h. Remove tetrahydrofuran by rotary evaporation. Pour in ethyl acetate in 7 times the mass of the antibacterial precursor to precipitate. Filter. Repeat 4 times. Dry at 65 °C for 22 h to obtain the antibacterial monomer. (2) Weigh out polybutylene adipate diol, isophorone diisocyanate, dimethylolpropionic acid and antibacterial monomer in a molar ratio of 1:2.5:1:0.6; mix the antibacterial monomer and acetone in a mass ratio of 1:2 and stir for 5 min at room temperature to obtain an antibacterial monomer solution; mix polybutylene adipate diol and isophorone diisocyanate in a homogeneous manner, add dibutyltin dilaurate at a mass ratio of 0.02 times that of polybutylene adipate diol, heat to 85°C under nitrogen protection, stir for 1 h to obtain a polyurethane prepolymer; add dimethylolpropionic acid and antibacterial monomer solution to the polyurethane prepolymer, cool to 70°C, stir for 1.5 h, add triethylamine equimolar of dimethylolpropionic acid, cool to 40°C, stir for 40 min, add deionized water to make the solid content 30%, shear at high speed for 500 min at room temperature, remove acetone by rotary evaporation to obtain an aqueous polyurethane emulsion; (3) Mix 4-carboxyphenylboronic acid and thionyl chloride at a mass ratio of 1:17, and reflux and stir at 85°C for 10 h under nitrogen protection. Remove thionyl chloride by rotary evaporation to obtain a self-healing crosslinking agent. Mix the self-healing crosslinking agent and waterborne polyurethane emulsion at a mass ratio of 1:250, and stir and react at 40°C for 50 min under nitrogen protection to obtain a functionalized waterborne polyurethane emulsion. (4) Mix 100 parts cement, 11 parts fly ash and 160 parts river sand evenly by weight, and dry mix at room temperature for 2 minutes to obtain a mixed dry material; mix 40 parts water, 3.5 parts functionalized waterborne polyurethane emulsion, 1.1 parts water-reducing agent and 0.3 parts defoamer evenly, stir at room temperature for 1 minute, add the mixed dry material, stir for 5 minutes to obtain a building waterproof repair material.

[0023] Comparative Example 1: The difference between the preparation method of the building waterproofing repair material of Comparative Example 1 and Example 2 is that step (1) is omitted, and step (2) is changed to: weighing polybutylene adipate diol, isophorone diisocyanate, and dimethylolpropionic acid in a molar ratio of 1.5:2.3:0.9:0.5; mixing polybutylene adipate diol and isophorone diisocyanate evenly, adding dibutyltin dilaurate at 0.015 times the mass of polybutylene adipate diol, heating to 80°C under nitrogen protection, stirring and reacting for 1.5 h to obtain a polyurethane prepolymer; adding dimethylolpropionic acid to the polyurethane prepolymer, cooling to 65°C, stirring and reacting for 2 h, adding triethylamine equimolar of dimethylolpropionic acid, cooling to 35°C, stirring for 45 min, adding deionized water to make the solid content 25%, and high-speed shearing at room temperature for 60 min to obtain an aqueous polyurethane emulsion. The remaining steps are the same as in Example 2.

[0024] Comparative Example 2: The difference between the preparation method of the building waterproofing repair material of Comparative Example 2 and Example 2 is that step (3) is omitted, and the "3 parts functionalized waterborne polyurethane emulsion" in step (4) is changed to 3 parts waterborne polyurethane emulsion. The remaining steps are the same as in Example 2.

[0025] Test Example 1 Antibacterial and antifungal performance test Test methods: The waterproofing and repair materials for buildings used in the examples and comparative examples were prepared into specimens of 50×50×2mm. After standard curing for 28 days, the antibacterial rate of the specimens against Escherichia coli was tested according to GB / T 21866-2008, using ordinary cement board as a control sample. The growth of Aspergillus niger on the specimens was tested using the petri dish method according to GB / T 1741-2020. The results are shown in Table 1.

[0026] Table 1 ; A comparison of the experimental data from Examples 1-3 and Comparative Examples 1-2 in Table 1 reveals that the building waterproofing repair material prepared by the present invention has good antibacterial and antifungal properties.

[0027] By comparison, the antibacterial rate and Aspergillus niger growth of Examples 1-3 were better than those of Comparative Example 1, indicating that the antibacterial monomer was prepared by adding 1-vinylimidazolium and 3-mercapto-1,2-propanediol and then quaternizing it with 3-chloropropyltrimethoxysilane; by using the tertiary amine nitrogen atom on the imidazole ring to quaternize with 3-chloropropyltrimethoxysilane, a quaternary ammonium salt antibacterial group was introduced, giving the building waterproofing and repair material excellent broad-spectrum antibacterial and antifungal properties.

[0028] Test Example 2 Interfacial adhesion performance test Test method: According to JC / T 984-2011 and JC / T 907-2002, the 28-day bond strength of the waterproofing repair materials for buildings in the examples and comparative examples to the cement interface was tested. The results are shown in Table 2.

[0029] Table 2 ; A comparison of the experimental data from Examples 1-3 and Comparative Examples 1-2 in Table 2 reveals that the building waterproofing repair material prepared by the present invention has good interfacial bonding performance.

[0030] By comparison, the bonding strength of Examples 1-3 is greater than that of Comparative Example 1, indicating that the antibacterial monomer is prepared by adding 1-vinylimidazolium and 3-mercapto-1,2-propanediol and then quaternizing it with 3-chloropropyltrimethoxysilane; the introduction of trimethoxysilane groups achieves chemical anchoring with the cement matrix, thereby giving the building waterproofing and repair material excellent interfacial bonding performance.

[0031] Test Example 3 Waterproofing performance test Test method: According to GB / T 18445-2025, the initial seepage resistance pressure at 28 days and the secondary seepage resistance pressure at 56 days of the test examples and comparative examples of the building waterproofing repair materials were used to evaluate the seepage resistance performance of the building waterproofing repair materials. The results are shown in Table 3.

[0032] Table 3 ; A comparison of the experimental data from Examples 1-3 and Comparative Examples 1-2 in Table 3 reveals that the building waterproofing repair material prepared by the present invention has good waterproofing performance.

[0033] By comparison, the initial anti-seepage pressure of Examples 1-3 was greater than that of Comparative Example 1, indicating that the addition reaction of 1-vinylimidazolium and 3-mercapto-1,2-propanediol, followed by the quaternization reaction with 3-chloropropyltrimethoxysilane, produces an antibacterial monomer. The introduction of the trimethoxysilane group achieves chemical anchoring with the cement matrix, enabling the waterborne polyurethane material to fill the matrix pores and block seepage channels after film formation, thus giving the building waterproofing and repair material excellent anti-seepage performance.

[0034] By comparison, the secondary seepage resistance pressure of Examples 1-3 was greater than that of Comparative Example 2, indicating that the self-condensation of 4-carboxyphenylboronic acid in thionyl chloride yielded a trifunctional self-healing crosslinking agent with a dynamic triboroxane structure. The self-healing crosslinking agent was reacted with an aqueous polyurethane emulsion to prepare a functionalized aqueous polyurethane emulsion. Dynamic borate ester bonds were covalently grafted into the polyurethane molecular chain to construct a three-dimensional dynamic crosslinking network. The self-healing of cracks was achieved through the reversible breakage and reconstruction of borate ester bonds, which improved the mechanical strength and water resistance of the polyurethane cement-based material after compounding, thereby further improving the seepage resistance performance of the building waterproofing and repair material.

[0035] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A building waterproofing and repair material, characterized in that, The building waterproofing and repair material is prepared by adding 1-vinylimidazol and 3-mercapto-1,2-propanediol, followed by quaternization with 3-chloropropyltrimethoxysilane to obtain an antibacterial monomer; extending the chain of a polyurethane prepolymer with dimethylolpropionic acid and the antibacterial monomer, then emulsifying with deionized water to obtain an aqueous polyurethane emulsion; reacting a self-healing crosslinking agent with the aqueous polyurethane emulsion to obtain a functionalized aqueous polyurethane emulsion; and mixing water, the functionalized aqueous polyurethane emulsion, a water-reducing agent, and a defoamer, then adding the mixed dry materials and stirring to obtain the final product. The polyurethane prepolymer is prepared by reacting polybutylene adipate diol and isophorone diisocyanate. The self-healing crosslinking agent is prepared by self-condensation of 4-carboxyphenylboronic acid in thionyl chloride. The mixed dry material is prepared by mixing cement, fly ash, and river sand.

2. A method for preparing a building waterproofing and repair material, characterized in that, The preparation method of the building waterproofing and repair material includes the following preparation steps: (1) Mix 3-mercapto-1,2-propanediol, tetrahydrofuran, and azobisisobutyronitrile in a mass ratio of 1:(9~11):(0.008~0.01) until homogeneous. Stir at room temperature for 10~20 min. Add 1-vinylimidazole in equimolar amounts of 3-mercapto-1,2-propanediol. Heat to 55~65℃ and stir for 7~9 h. Add 3-chloropropyltrimethoxysilane and continue stirring for 46~50 h. Remove tetrahydrofuran by rotary evaporation. Pour in 5~7 times the mass of the antibacterial precursor in ethyl acetate to precipitate and filter. Repeat 2~4 times. Dry at 55~65℃ for 22~26 h to obtain the antibacterial monomer. (2) Polybutylene adipate diol and isophorone diisocyanate were prepared into a polyurethane prepolymer; antibacterial monomers were prepared into an antibacterial monomer solution; dimethylolpropionic acid and antibacterial monomer solution were added to the polyurethane prepolymer, the temperature was lowered to 60~70℃, the reaction was stirred for 1.5~2.5h, triethylamine of equimolar amount of dimethylolpropionic acid was added, the temperature was cooled to 30~40℃, the mixture was stirred for 40~50min, deionized water was added to make the solid content 20~30%, the mixture was subjected to high-speed shearing at room temperature for 50~70min, and acetone was removed by rotary evaporation to obtain an aqueous polyurethane emulsion; (3) Mix the self-healing crosslinking agent and the waterborne polyurethane emulsion at a mass ratio of 1:(150~250), and stir and react at 30~40℃ for 50~70 min under nitrogen protection to obtain the functionalized waterborne polyurethane emulsion. (4) By mass, mix 30-40 parts water, 2.5-3.5 parts functionalized waterborne polyurethane emulsion, 0.9-1.1 parts water-reducing agent, and 0.1-0.3 parts defoamer evenly, stir at room temperature for 1-3 minutes, add the mixed dry material, stir for 5-15 minutes, and obtain the building waterproof repair material.

3. The method for preparing the building waterproofing and repair material according to claim 2, characterized in that, The amount of 3-chloropropyltrimethoxysilane added in step (1) is 1 to 1.2 times the molar amount of 3-mercapto-1,2-propanediol.

4. The method for preparing the building waterproofing and repair material according to claim 2, characterized in that, The molar ratio of polybutylene adipate diol, isophorone diisocyanate, dimethylolpropionic acid and antibacterial monomer in step (2) is 1:(2.1~2.5):(0.8~1):(0.4~0.6).

5. The method for preparing the building waterproofing and repair material according to claim 2, characterized in that, The preparation method of the polyurethane prepolymer in step (2) is as follows: polybutylene adipate diol and isophorone diisocyanate are mixed evenly in a molar ratio of 1:(2.1~2.5), and 0.01~0.02 times the mass of polybutylene adipate diol diol dibutyltin dilaurate is added. Under nitrogen protection, the temperature is raised to 75~85℃ and stirred for 1~2 hours to obtain the polyurethane prepolymer.

6. The method for preparing the building waterproofing and repair material according to claim 2, characterized in that, The method for preparing the antimicrobial monomer solution in step (2) is as follows: mix the antimicrobial monomer and acetone at a mass ratio of 1:(1.6~2) evenly, stir at room temperature for 5~15 minutes to obtain the antimicrobial monomer solution.

7. The method for preparing the building waterproofing and repair material according to claim 2, characterized in that, The preparation method of the self-healing crosslinking agent in step (3) is as follows: 4-carboxyphenylboronic acid and thionyl chloride are mixed evenly at a mass ratio of 1:(15~17), and under nitrogen protection, the mixture is refluxed and stirred at 75~85℃ for 10~12h. The thionyl chloride is removed by rotary evaporation to obtain the self-healing crosslinking agent.

8. The method for preparing the building waterproofing and repair material according to claim 2, characterized in that, The type of water-reducing agent mentioned in step (4) is: polycarboxylate water-reducing agent; the type of defoamer is TCX-1 silicone defoamer.

9. The method for preparing the building waterproofing and repair material according to claim 2, characterized in that, The preparation method of the mixed dry material in step (4) is as follows: 80-100 parts of cement, 9-11 parts of fly ash and 140-160 parts of river sand are mixed evenly by mass and dry-mixed at room temperature for 2-4 minutes to obtain the mixed dry material.

10. The method for preparing the building waterproofing and repair material according to claim 9, characterized in that, The cement is P·O 42.5 grade ordinary Portland cement; the fly ash is grade 1 fly ash with a particle size of 400 mesh; the river sand has a particle size of 30 mesh.