Water-triggered adhesive as well as preparation method and application thereof

Abstract

The invention provides a water-triggered adhesive as well as a preparation method and application thereof. The adhesive comprises a mixture and / or a reaction product of a substituted glyceryl ether compound, a nitrogen heterocyclic compound and optional nano silicon dioxide. The adhesive adopts a water triggering mechanism, can be quickly activated after being in contact with water, realizes strong bonding, shows excellent underwater performance, and is particularly suitable for multiple application scenes such as underwater repair, ocean engineering and ship repair. The preparation method of the adhesive is simple to operate, environment-friendly and suitable for large-scale production. A test result shows that the adhesive can be continuously polymerized in an underwater environment, the cohesion is enhanced, a long-term stable repairing effect is provided, and the wide application prospect is shown.

Description

Technical Field

[0001] The invention belongs to the technical field of adhesives, and in particular relates to a water-triggered adhesive and a preparation method and application thereof. Background Art

[0002] With the development of marine engineering, subsea equipment maintenance, ship repair and other fields, the demand for underwater operations is increasing, especially in underwater structure repair, equipment connection, sealing and underwater construction. The demand for underwater adhesives is growing. Traditional underwater adhesives face many challenges in practical applications, mainly including insufficient adhesion, poor water resistance, and difficulty in maintaining long-term stability in underwater environments. Especially in dynamic water environments (such as water flow, waves, salinity and temperature changes, etc.), the performance of traditional underwater adhesives is relatively limited and often cannot meet the requirements of high strength, long life and resistance to environmental stress.

[0003] Most existing underwater adhesives rely on curing agents or chemical cross-linking reactions, but these adhesives usually require a long reaction time or are sensitive to environmental conditions, which limits their application scope. In addition, many underwater adhesives are difficult to quickly activate their bonding properties when exposed to water, which makes them less effective in emergency repairs or quick repairs. Therefore, there is an urgent need for an underwater adhesive that can be quickly activated in an underwater environment and has strong bonding strength to adapt to the complex and changing underwater environment. Summary of the invention

[0004] The present invention provides a water-triggered adhesive, which can be quickly activated and achieve strong bonding after contacting water by adopting a water-triggered mechanism. The adhesive combines the synergistic effect of non-covalent interaction and covalent bond, and has strong bonding performance that is adaptive in an underwater environment.

[0005] One of the objects of the present invention is to provide a water-triggered adhesive comprising a mixture and / or a reaction product of a substituted glycerol ether compound, a nitrogen heterocyclic compound and optional nano-silica, wherein the substituent group in the substituted glycerol ether compound is selected from at least one of a siloxane group and an alkoxysilane group.

[0006] According to the present invention, in the water-triggered adhesive:

[0007] The substituted glyceryl ether compound is selected from at least one of 3-(2,3-epoxypropyloxy)propyltrimethoxysilane, 3-glycidyloxypropyltriethoxysilane, (3-glycidyloxypropyl)-1,1,3,3-tetramethyldisiloxane, tert-butyldimethylsilyl glycidyl ether (such as tert-butyldimethylsilyl|S|-(+)-glycidyl ether, tert-butyldimethylsilyl (R)-(-)-glycidyl ether), 2,4,6,8-tetramethyl-2,4,6,8-tetra(propyl glycidyl ether)cyclotetrasiloxane, and poly(dimethylsiloxane) diglycidyl ether;

[0008] The nitrogen heterocyclic compound is selected from at least one of nitrogen heterocyclic compounds with amino and / or thiol groups, preferably at least one of imidazole derivatives, pyrimidine derivatives, pyridine derivatives, indole derivatives, triazole derivatives, thiophene derivatives, thiazole derivatives, thiadiazole derivatives, and pyrazole derivatives with amino and / or thiol groups, and more preferably 2,4-dimercaptoimidazole, 1,2-diaminoimidazole, 2-amino-4-mercaptoimidazole, 1-amino-3-mercaptoimidazole, 2,4-diamino-6-mercaptopyrimidine, 2,4,6-trimercaptopyrimidine, 2-amino-4-mercaptopyrimidine, 2-mercapto 4-aminopyrimidine, 4-amino-2-mercaptopyrimidine, 6-amino-2-mercaptopyrimidine, 5-amino-2-mercaptopyrimidine, 2,4-dimercaptopyridine, 2,4-diaminopyridine, 2-amino-5-mercaptopyridine, 3-amino-2-mercaptopyridine, 6-amino-3-mercaptopyridine, 3,5-diaminopyrazole, 3,5-dimercaptopyrazole, 4-amino-3-mercaptopyrazole, 1-amino-3-mercaptopyrazole, 2-amino-3-mercaptoindole, 3-amino-6-mercaptoindole, 1-mercapto-3-phenyl-1,2,4-triazole, 1-amino-3-mercapto-1,2,3-triazole, At least one of 3-amino-5-mercapto-1,2,3-triazole, 5-amino-1-mercapto-1,2,3-triazole, 4-amino-2-mercaptothiophene, 2-amino-5-mercaptothiophene, 2-amino-1-mercaptothiazole, 2-amino-5-mercaptothiazole, 3-amino-2-mercaptothiazole, 3-mercapto-4-aminothiazole, 3-amino-1,2-mercaptothiadiazole, 2-amino-1,3-mercaptothiadiazole, 2-mercapto-4-aminothiazole, and 2-amino-5-mercapto-1,3,4-thiadiazole; further, considering the cost and reactivity of the nitrogen heterocyclic compound, the nitrogen The heterocyclic compound is preferably selected from at least one of nitrogen heterocyclic compounds having an amino group and a thiol group, and the nitrogen heterocyclic compound is preferably selected from at least one of 2-amino-5-thiopyridine, 3-amino-2-thiopyridine, 4-amino-3-thiopyrazole, 1-thio-3-phenyl-1,2,4-triazole, 5-amino-1-thio-1,2,3-triazole, 2-amino-5-thiothiophene, 2-amino-5-thiothiazole, 3-amino-2-thiothiazole, 2-amino-1,3-thiothiadiazole, 2-thio-4-aminothiadiazole, and 2-amino-5-thio-1,3,4-thiadiazole;

[0009] The nano silicon dioxide can be a commonly used nano silicon dioxide product, or can be prepared by a commonly used preparation method (sol-gel method, vapor deposition method, hydrothermal method, microemulsion method, spray pyrolysis method, mechanical ball milling method, liquid phase deposition method, reverse microemulsion method, direct combustion method, pyrolysis method, etc.); preferably, the particle size of the nano silicon dioxide is 1 to 100 nm, for example, it can be 1, 5, 10, 15, 20, 25, 30, 40, 50, 60, 70, 80, 90, 100 nm or a particle size range between any two of the above values; preferably, the particle size of the nano silicon dioxide is 15 to 30 nm;

[0010] Based on 1 part by weight of the nitrogen heterocyclic compound, the substituted glycerol ether compound is 1.5 to 5 parts by weight (for example, it can be 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5 parts by weight or a weight value between any two of the above numerical ranges), and the nano-silicon dioxide is 0 to 1 part by weight (for example, it can be 0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1 part by weight or a weight value between any two of the above numerical ranges); preferably, based on 1 part by weight of the nitrogen heterocyclic compound, the substituted glycerol ether compound is 3 to 4.5 parts by weight, and the nano-silicon dioxide is 0 to 0.5 part by weight.

[0011] The second object of the present invention is to provide a method for preparing the water-triggered adhesive, comprising the steps of mixing and reacting components including the substituted glycerol ether compound, the nitrogen heterocyclic compound and the optionally added nano-silicon dioxide to obtain the water-triggered adhesive.

[0012] According to the present invention, the preparation method specifically comprises:

[0013] (1) mixing the substituted glycerol ether compound and the nitrogen heterocyclic compound, and stirring to react;

[0014] (2) optionally adding nano-silicon dioxide to the product obtained in step (1) and continuing to stir the reaction to obtain the water-triggered adhesive.

[0015] Wherein, the stirring reaction conditions in step (1) are: 15-25° C., 400-1000 rpm, and reaction for 12-36 hours;

[0016] In the step (2), the nano silicon dioxide is added to the reaction system at least twice;

[0017] The stirring reaction conditions in step (2) are: 15-25° C., 400-1200 rpm, and 12-24 h.

[0018] As a preferred embodiment of the present invention, the preparation method of the water-triggered adhesive specifically includes: mixing the substituted glycerol ether compound and the nitrogen heterocyclic compound, stirring and reacting at 15-25° C. for 12-36 hours, optionally adding nano-silicon dioxide to the obtained product at least twice (for example, twice, three times, etc.), and continuing to stir and react at 15-25° C. for 12-24 hours to obtain the water-triggered adhesive.

[0019] The third object of the present invention is to provide a water-triggered adhesive prepared by the above preparation method.

[0020] A fourth object of the present invention is to provide a water-triggered adhesive for use in underwater repair operations, preferably for use in underwater repairs of wood, metal, glass, and resin.

[0021] The present invention realizes the synthesis of water-triggered adhesive by coupling reaction of substituted glycerol ether compounds, nitrogen heterocyclic compounds and optionally added nano-silicon dioxide. The obtained water-triggered adhesive has the following characteristics:

[0022] (1) Water-triggered activation mechanism: The adhesive is designed with components that can be triggered by water (such as hydrolyzable groups, hydrophilic groups, etc.). Among them, substituted glycerol ether compounds are used as water-triggered active functional groups. When the adhesive comes into contact with water, water molecules can activate the silane groups (siloxane groups, alkoxysilane groups, etc.) in it, promoting the chemical reaction or physical change of the adhesive, thereby achieving a rapid bonding effect.

[0023] (2) Network structure combining non-covalent and covalent forces: The underwater adhesive of the present invention forms a three-dimensional network structure with adaptive polymerization properties through the combined action of non-covalent interactions (such as hydrogen bonds, electrostatic attraction, van der Waals forces, etc.) and covalent cross-linking (chemical cross-linking). This network structure can quickly self-assemble after being triggered by water, and achieve unlimited polymerization over time, thereby providing strong cohesion and adhesion. Specifically, the multiple bonding action enables the adhesive to adhere quickly when it initially contacts the substrate (wood, metal, glass, resin) underwater, while the covalent cross-linking stabilizes the bonding layer through chemical reactions in the later stage, thereby improving the strength, durability and water resistance of the adhesive. Over time, the polymerization process of the network structure further enhances the cohesion of the adhesive, ensuring its long-term stability and toughness in complex underwater environments.

[0024] (3) Excellent underwater performance: The adhesive of the present invention can maintain high mechanical strength and water resistance in an underwater environment, and can maintain a stable bonding effect for a long time even in complex underwater environments such as salt water, acidity, alkalinity, and high humidity. The adhesive also has good corrosion resistance and crack resistance, and can withstand large external forces or water flow impacts.

[0025] (4) Broad application prospects: The water-triggered adhesive of the present invention is suitable for various underwater operations, including marine engineering, underwater repair, deep-sea exploration equipment connection, ship repair and other fields, especially in rapid repair or emergency situations.

[0026] The present invention adopts nitrogen heterocyclic compounds, substituted glycerol ether compounds and optionally added nano-silicon dioxide. When the components are used in combination, the best performance balance and performance can be obtained, thereby improving the overall performance of the prepared water-triggered adhesive; and the water-triggered adhesive cures quickly during application, which is conducive to industrial application.

[0027] The beneficial effects of the present invention are at least:

[0028] 1) The present invention replaces the nucleophilic addition reaction of the silane group in the glycerol ether compound with the amino or thiol group in the nitrogen heterocyclic compound, and by stirring and mixing and optionally adding nano silicon dioxide in batches, the nano silicon dioxide is evenly distributed in the reaction system. This process can form a condensation reaction, further generate a multi-crosslinked network structure, and achieve the effect of stress balance. This means that the strength, toughness and stability of the final material will be significantly improved, especially in the stress concentration area, can effectively disperse stress and improve durability.

[0029] 2) The water-triggered adhesive produced by the present invention has a water-triggered function, that is, with the participation of water, the adhesive can react with water to perform a cohesive condensation reaction. The reaction can not only remove moisture from the surface of the substrate, but also promote unlimited polymerization inside the adhesive to form a multi-dimensional cross-linked network structure. This property enables the adhesive to work effectively in an underwater environment and provide continuous strong adhesion, which can adapt to the needs of underwater or wet environments, enhance the cohesive force of the adhesive, and thus improve its long-term performance and durability.

[0030] 3) The water-triggered adhesive provided by the present invention generates silicon-oxygen bonds when undergoing condensation reaction with the hydroxyl groups on the surface of the substrate, and can undergo chemical crosslinking reaction with the surfaces of different substrate materials (such as wood, metal, glass, and resin). This chemical crosslinking makes the adhesive have strong adhesion on the surface of the substrate. This feature is particularly important for the repair of the substrate, especially when repairing different materials such as wood, metal, glass, or resin, it can provide a good repair effect and enhance the strength and durability of the bond.

[0031] 4) The water-triggered adhesive provided by the present invention has high synthesis efficiency, no harmful substance release, high product reactivity, good processability, stable performance in each batch, low cost, and is conducive to industrial application.

[0032] Experiments have shown that the water-triggered adhesive provided by the present invention can solve the practical application problems of underwater adhesives. The prepared water-triggered adhesive has many excellent properties and is suitable for a variety of materials that require strong bonding and repair, especially in underwater and wet environments, and has significant application advantages. DETAILED DESCRIPTION

[0033] The preferred embodiments of the present invention will be described in detail below in conjunction with examples. It should be understood that the following examples are provided only for the purpose of illustration and are not intended to limit the scope of the present invention. Those skilled in the art may make various modifications and substitutions to the present invention without departing from the purpose and spirit of the present invention.

[0034] The experimental methods used in the following examples are conventional methods unless otherwise specified. The materials, reagents, etc. used in the following examples are all commercially available unless otherwise specified.

[0035] In the present invention, if the percentage sign "%" is involved, it refers to mass percentage unless otherwise specified; however, the percentage of a solution, unless otherwise specified, refers to the number of grams of solute contained in 100 mL of the solution; the percentage between liquids refers to the ratio of the volumes at 20°C.

[0036] The nitrogen heterocyclic compounds, substituted glycerol ether compounds and nano-silicon dioxide used in the examples of the present invention were purchased from Science Compass Co., Ltd.

[0037] Example 1

[0038] This embodiment provides a water-triggered adhesive of the present invention and a preparation method thereof. Specifically:

[0039] 1. Prepare materials: 45 kg of 3-(2,3-epoxypropoxy)propyltrimethoxysilane, 10 kg of nitrogen heterocyclic compound: 2-amino-5-mercapto-1,3,4-thiadiazole, and 5 kg of silicon dioxide with a particle size of 15 to 30 nanometers.

[0040] 2. Preparation of water-triggered adhesive:

[0041] 10 kg of 2-amino-5-mercapto-1,3,4-thiadiazole was added to 45 kg of 3-(2,3-epoxypropoxy)propyltrimethoxysilane and mechanically stirred at 800 rpm and 15°C for 36 hours. Then, 5 kg of nano-silicon dioxide was added in three times and mechanical stirring was continued for 24 hours until a uniform light yellow viscous material was obtained.

[0042] Example 2

[0043] This embodiment provides a water-triggered adhesive of the present invention and a preparation method thereof. The specific preparation method is the same as that of Example 1, except that when preparing the materials, the composition of the materials is changed and nano-silicon dioxide is not added. Specifically: 45 kg of 3-(2,3-epoxypropoxy)propyltrimethoxysilane and 10 kg of 2-amino-5-mercapto-1,3,4-thiadiazole.

[0044] Example 3

[0045] This embodiment provides a water-triggered adhesive of the present invention and a preparation method thereof. The specific preparation method is the same as that of Example 1, except that the composition of the prepared materials is changed during the preparation. Specifically: 45 kg of 3-(2,3-epoxypropoxy)propyltrimethoxysilane, 10 kg of 5-amino-1-mercapto-1,2,3-triazole, and 5 kg of nano-silicon dioxide.

[0046] Example 4

[0047] This embodiment provides a water-triggered adhesive of the present invention and a preparation method thereof. The specific preparation method is the same as that of Example 1, except that the composition of the prepared materials is changed during the preparation. Specifically: 45 kg of poly(dimethylsiloxane) diglycidyl ether, 10 kg of 2-amino-5-mercaptopyridine, and 5 kg of nano-silicon dioxide.

[0048] Test Example 1

[0049] The bonding strength was tested by overlapping the adhesive and applying the adhesive to the substrate underwater. The coating area was 25×25mm. 2 , glue the two substrates together and place them in water for curing for 24 hours, clamp them with a 32mm long-tail clamp, and after curing, use a universal mechanical testing machine to test the lap shear strength, i.e. the bonding strength, at a tensile rate of 20mm / s.

[0050] Table 1 shows the bonding strength of the adhesives of Examples 1-4 of the present invention to wood, stainless steel, and PVC at room temperature.

[0051] Table 1

[0052]

[0053] The results in Table 1 show that the adhesive of the present invention exhibits excellent underwater bonding performance for wood, stainless steel and PVC.

[0054] Table 2 shows the bonding strength of the adhesives of Examples 1-4 of the present invention to wood, stainless steel, and PVC at 78°C.

[0055] Table 2

[0056]

[0057] The results show that the adhesive of the present invention still exhibits strong bonding ability to the substrate under high temperature conditions, indicating that it has good environmental stability.

[0058] Test Example 2

[0059] The bonding strength of the adhesive prepared in Example 1 of the present invention for two substrates, wood and stainless steel, was compared with other currently reported underwater adhesives. The results are shown in Table 3-4.

[0060] Table 3 is a comparison of the bonding strength of the adhesive prepared in Example 1 of the present invention and other underwater adhesives to wood at room temperature (cured for 24 hours).

[0061] Table 3

[0062]

[0063] The adhesives in Table 3 were obtained by the following method:

[0064] Hexamethylene diisocyanate-bis(3-aminopropyl)-terminated polydimethylsiloxane adhesive: obtained by the preparation method disclosed by Ran, Q. et al. in "Using self-synthesized aminopropyl-terminated polydimethylsiloxane to toughen epoxy resin: The role of molecular weight of polydimethylsiloxane" (Journal of Vinyl and Additive Technology 2017, 23(4), 305-311);

[0065] Poly[(3,4-dihydroxystyrene)-costyrene adhesive: obtained by the preparation method disclosed by Meredith, HJ et al. in "Enhancing the Adhesion of a Biomimetic Polymer Yields Performance Rivaling Commercial Glues" (Adv. Funct. Mater. 2014, 24(21), 3259-3267);

[0066] Polyamide dihydrocaffeic acid-epichlorohydrin adhesive: obtained by the preparation method disclosed by Ma, C. et al. in "Facile strategy of mussel-inspired polymer as a high-performance dry / wet adhesive" (J.CleanProd.2021,308);

[0067] Mineral-reinforced hydrogels: prepared by the preparation method disclosed by Liu, J. et al. in "Amorphous biomineral-reinforced hydrogels with dramatically enhanced toughness for strain sensing" (Chem. Eng. J. 2023, 468);

[0068] 4 (Dibenzo-24-crown-8)-four-arm pentaerythritol adhesive: obtained by the preparation method disclosed by Ji, S. et al. in "Water-resistant conformal hybrid electrodes for aquatic endurable electrocardiographic monitoring" (Adv. Mater. 2020, 32 (26), 2001496);

[0069] Tannic acid-polycation adhesive: obtained by the preparation method disclosed by Wang, Z. et al. in "Facile biomimetic self-coacervation of tannic acid and polycation: Tough and wide pH range of underwater adhesives" (Chem. Eng. J. 2021, 404).

[0070] Table 4 is a comparison of the bonding strength of the adhesive prepared in Example 1 of the present invention and other underwater adhesives to metals at room temperature underwater (cured for 24 hours).

[0071] Table 4

[0072]

[0073] The adhesives in Table 4 were obtained by the following method:

[0074] Polyester catechol adhesive: obtained by the preparation method disclosed by Xu, Y. et al. in "Mussel-Inspired Polyesters with Aliphatic Pendant Groups Demonstrate the Importance of Hydrophobicity in Underwater Adhesion" (Advanced Materials Interfaces 2017, 4 (22), 1700506).

[0075] 2-(Methacryloyloxy)ethylphosphodopamine methacrylamide + poly(acrylamide-coaminopropyl methacrylamide) adhesive: obtained by the preparation method disclosed by Kaur, S. et al. in "Multiphase adhesive coatings inspired by the Sandcastle worm" (ACS Appl. Mater. Interfaces 2011, 3(4), 941-944).

[0076] Polyacrylic acid chain + amorphous CaCO3: obtained by the preparation method disclosed by Li, A. et al. in "Mineral-enhanced polyacrylicacid hydrogel as an oyster-inspired organic–inorganic hybrid adhesive" (ACS Appl. Mater. Interfaces 2018, 10 (12), 10471-10479).

[0077] PAE-TFSI coacervate adhesive: obtained by the preparation method disclosed by Zhu, X. et al. in "Arobust salty water adhesive by counterion exchange induced coacervate" (Macromol. Rapid Commun. 2019, 40(7), 1800758).

[0078] The results in Table 3-4 show that the underwater bonding strength of the adhesive of the present invention for wood and stainless steel is significantly better than that of the currently reported underwater adhesives.

[0079] Test Example 3

[0080] At room temperature, the adhesive prepared in Example 1 of the present invention was applied to different substrates (iron, stainless steel, copper, polyethylene terephthalate, acrylonitrile-butadiene-styrene copolymer, polyethylene) in different solutions (water, seawater, acidic solution, alkaline solution), cured under the pressure of a 32 mm binder clamp and left for 1 month. The bonding strength was tested according to the method of Test Example 1. The results are shown in Tables 5-8.

[0081] Table 5 shows the bonding strength of the adhesive prepared in Example 1 of the present invention to different substrates when placed underwater for 72 hours, 7 days, and 1 month.

[0082] Table 5

[0083]

[0084] Table 6 shows the bonding strength of the adhesive prepared in Example 1 of the present invention to different substrates when placed under seawater for 72 hours, 7 days, and 1 month.

[0085] Table 6

[0086]

[0087] Table 7 shows the bonding strength of the adhesive prepared in Example 1 of the present invention to different substrates when placed in an acidic solution (pH=3) for 72 hours, 7 days, and 1 month.

[0088] Table 7

[0089]

[0090] Table 8 shows the bonding strength of the adhesive prepared in Example 1 of the present invention to different substrates when placed in an alkaline solution (pH=10) for 72 hours, 7 days, and 1 month.

[0091] Table 8

[0092]

[0093] The results in Tables 5-8 show that the adhesive strength of the adhesive of the present invention to the substrate changes little under different aqueous solution environments. The adhesive of the present invention is placed in different solutions for 1 month, and for most substrates, its bonding strength is equivalent to that of the adhesive cured for 24 hours, showing excellent durability.

[0094] Although the present invention has been described in detail above with general descriptions and specific embodiments, it is obvious to those skilled in the art that some modifications or improvements may be made thereto based on the present invention. Therefore, these modifications or improvements made without departing from the spirit of the present invention all fall within the scope of protection claimed by the present invention.

Claims

1. A water-triggered adhesive comprising a mixture and / or a reaction product of a substituted glycerol ether compound, a nitrogen heterocyclic compound and optionally nano-silicon dioxide, wherein: The substituent group in the substituted glyceryl ether compound is selected from at least one of a siloxane group and an alkoxysilane group.

2. The water-triggered adhesive according to claim 1, characterized in that: The substituted glyceryl ether compound is selected from at least one of 3-(2,3-epoxypropyloxy)propyltrimethoxysilane, 3-glycidyloxypropyltriethoxysilane, (3-glycidyloxypropyl)-1,1,3,3-tetramethyldisiloxane, tert-butyldimethylsilyl glycidyl ether, 2,4,6,8-tetramethyl-2,4,6,8-tetra(propyl glycidyl ether)cyclotetrasiloxane, and poly(dimethylsiloxane) diglycidyl ether.

3. The water-triggered adhesive according to claim 1, characterized in that: The nitrogen heterocyclic compound is selected from at least one of nitrogen heterocyclic compounds with amino and / or thiol groups, preferably at least one of imidazole derivatives, pyrimidine derivatives, pyridine derivatives, indole derivatives, triazole derivatives, thiophene derivatives, thiazole derivatives, thiadiazole derivatives, and pyrazole derivatives with amino and / or thiol groups, more preferably 2,4-dimercaptoimidazole, 1,2-diaminoimidazole, 2-amino-4-mercaptoimidazole, 1-amino-3-mercaptoimidazole, 2,4-diamino-6-mercaptopyrimidine, 2,4,6-trimercaptopyrimidine , 2-amino-4-mercaptopyrimidine, 2-mercapto-4-aminopyrimidine, 4-amino-2-mercaptopyrimidine, 6-amino-2-mercaptopyrimidine, 5-amino-2-mercaptopyrimidine, 2,4-dimercaptopyridine, 2,4-diaminopyridine, 2-amino-5-mercaptopyridine, 3-amino-2-mercaptopyridine, 6-amino-3-mercaptopyridine, 3,5-diaminopyrazole, 3,5-dimercaptopyrazole, 4-amino-3-mercaptopyrazole, 1-amino-3-mercaptopyrazole, 2-amino-3-mercaptoindole, 3-amino-6-mercaptoindole, 1-mercapto-3 -phenyl-1,2,4-triazole, 1-amino-3-mercapto-1,2,3-triazole, 3-amino-5-mercapto-1,2,3-triazole, 5-amino-1-mercapto-1,2,3-triazole, 4-amino-2-mercaptothiophene, 2-amino-5-mercaptothiophene, 2-amino-1-mercaptothiazole, 2-amino-5-mercaptothiazole, 3-amino-2-mercaptothiazole, 3-mercapto-4-aminothiazole, 3-amino-1,2-mercaptothiadiazole, 2-amino-1,3-mercaptothiadiazole, 2-mercapto-4-aminothiadiazole, 2-amino- At least one of 5-mercapto-1,3,4-thiadiazoles, further preferably at least one of 2-amino-5-mercaptopyridine, 3-amino-2-mercaptopyridine, 4-amino-3-mercaptopyrazole, 1-mercapto-3-phenyl-1,2,4-triazole, 5-amino-1-mercapto-1,2,3-triazole, 2-amino-5-mercaptothiophene, 2-amino-5-mercaptothiazole, 3-amino-2-mercaptothiazole, 2-amino-1,3-mercaptothiadiazole, 2-mercapto-4-aminothiadiazole, and 2-amino-5-mercapto-1,3,4-thiadiazole.

4. The water-triggered adhesive according to claim 1, characterized in that: The particle size of the nano-silicon dioxide is 1 to 100 nm, preferably 15 to 30 nm.

5. The water-triggered adhesive according to claim 1, characterized in that: Based on 1 part by weight of the nitrogen heterocyclic compound, the substituted glycerol ether compound is 1.5 to 5 parts by weight, and the nano-silicon dioxide is 0 to 1 part by weight; preferably, based on 1 part by weight of the nitrogen heterocyclic compound, the substituted glycerol ether compound is 3 to 4.5 parts by weight, and the nano-silicon dioxide is 0 to 0.5 parts by weight.

6. A method for preparing the water-triggered adhesive according to any one of claims 1 to 5, comprising the step of mixing and reacting components including the substituted glycerol ether compound, the nitrogen heterocyclic compound and optionally added nano-silicon dioxide to obtain the water-triggered adhesive.

7. The preparation method according to claim 6, characterized in that: The preparation method specifically comprises: (1) mixing the substituted glycerol ether compound and the nitrogen heterocyclic compound, and stirring to react; (2) optionally adding nano-silicon dioxide to the product obtained in step (1) and continuing to stir the reaction to obtain the water-triggered adhesive.

8. The preparation method according to claim 7, characterized in that: The stirring reaction conditions in step (1) are: 15-25° C., 400-1000 rpm, and 12-36 hours; and / or, In the step (2), the nano-silicon dioxide is added to the reaction system at least twice; and / or, The stirring reaction conditions in step (2) are: 15-25° C., 400-1200 rpm, and 12-24 h.

9. A water-triggered adhesive prepared by the preparation method according to any one of claims 6 to 8.

10. Use of the water-triggered adhesive according to any one of claims 1 to 5 or the water-triggered adhesive according to claim 9 in underwater repair operations, preferably in underwater repairs of wood, metal, glass, and resin.

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