Nanometer material for wall cable trench cavity water stop and preparation method thereof

Abstract

The application relates to the technical field of building materials, and particularly discloses a kind of nanometer materials for wall cable trench cavity water stop and a preparation method thereof, which comprises the following raw materials in parts by weight: sebacic acid 5-10 parts, acrylic acid 50-70 parts, olivine powder 10-20 parts, magnesium aluminum silicate 10-20 parts, calcium acrylate 20-30 parts, aluminate coupling agent 1-2 parts, curing agent 1-2 parts, coagulant 1-2 parts, water reducing agent 1-2 parts, modified additive 1-2 parts, deionized water 30-40 parts, ammonium persulfate 0.5-1 part. The modified additive has phosphorus, silicon, fluorine elements and long-chain alkyl on the molecular structure, and the modified additive and other raw materials significantly improve the flame retardance, compressive strength, chemical stability and waterproof performance of the nanometer material for wall cable trench cavity water stop through synergistic effect. Meanwhile, the modified additive also reduces the agglomeration phenomenon among raw materials, ensuring that the nanometer material has good strength and water plugging effect.

Description

Technical Field

[0001] This invention relates to the field of building materials technology, specifically to a nanomaterial for sealing the cavity of a cable trench in a wall and its preparation method. Background Technology

[0002] In recent years, with changes in climate change and geological conditions, power facilities such as cable trenches, cable wells, cable ducts, and ring main unit foundations face increasingly serious safety hazards in specific areas (such as areas with rising water levels and sandy soil). The environmental characteristics of these areas make it easy for cavities to form in the foundations of power facilities, leading to problems such as water accumulation, seepage, foundation subsidence, and collapse. These issues seriously threaten the safe and stable operation of power facilities and may even cause major safety accidents. Therefore, water-stopping materials that can effectively solve the above problems are receiving increasing attention, and the research and application of high-performance water-stopping materials have become a key measure to ensure the safety of power facilities.

[0003] Patent application CN201610206720.2 discloses a rapid-hardening, early-strength nanocomposite cement-based waterproofing and reinforcement material. Its components include: ordinary silicate cement, sulfoaluminate cement, nano-SiO2, lithium carbonate, sodium hydroxide, and a water-reducing agent; the remainder is water. The rapid-hardening, early-strength nanocomposite cement-based waterproofing and reinforcement material prepared by this invention has low admixture dosage, good initial fluidity, a final setting time of less than 10 minutes, an initial and final setting interval of no more than 3 minutes, and a 24-hour compressive strength exceeding 25 MPa. It has broad application prospects in drilling wall protection, shotcrete, leak sealing, dynamic water grouting, seepage prevention curtains, and large crack reinforcement in complex geological formations. However, although the sulfoaluminate cement used in this invention has advantages such as rapid hardening and early strength, its durability is poor, especially under high-temperature conditions where it is prone to decomposition, leading to a decrease in strength and expansion performance, affecting its effectiveness. Patent application number CN202110546932.6 discloses a polyurethane grouting material for foundation pit water sealing and its preparation method. The material is composed of the following components in parts by mass: 20-40 parts polyether polyol, 60-80 parts isocyanate, 0.3-2 parts catalyst, 4-8 parts foam stabilizer, 10-20 parts ethyl acetate, 0.5-1 parts nano-calcium carbonate, 0.5-1 parts nano-aluminum silicate, and 0.5-1.5 parts nano-zirconium carbide. First, the polyether polyol is heated to 100-130℃ and subjected to negative pressure dehydration and degassing treatment for 1.5-3.5 hours. After cooling to 20-40℃, isocyanate is added, and the mixture is reacted at 75-85℃ for 2-3 hours to obtain a prepolymer reaction liquid. Then, the temperature is lowered to 40-50℃, the foam stabilizer is added, and the mixture is further mixed. Ethyl acetate, the catalyst, and the nanomaterials are then added and thoroughly mixed to obtain the polyurethane grouting material. The polyurethane grouting material prepared by this invention for foundation pit water sealing exhibits good strength and water-stopping effect. This invention utilizes various nanomaterials such as nano-calcium carbonate, nano-aluminum silicate, and nano-zirconium carbide; however, a suitable dispersant was not used. Due to intermolecular forces and electrostatic interactions, the nanomaterials agglomerate, forming aggregates that result in uneven dispersion within the polyurethane matrix. This prevents the nanomaterials from fully exerting their reinforcing effects and negatively impacts the overall performance of the material.

[0004] Therefore, in order to meet the growing demand for waterproofing materials in modern building and engineering construction, it is still necessary to develop a new nanomaterial for waterproofing cable trench cavities in walls. Summary of the Invention

[0005] To address the aforementioned problems, this invention provides a weather-resistant cable insulation material and its preparation method. To ensure that the nanomaterials used for sealing cable trench cavities in walls can fully exert their waterproofing performance, it is necessary to reduce the agglomeration of inorganic raw materials and ensure that the nanomaterials maintain good performance even under harsh environments such as high temperatures.

[0006] The technical solution adopted by the present invention to achieve the above objectives is as follows:

[0007] A nanomaterial for sealing the cavity of a cable trench in a wall comprises the following raw materials in parts by weight: 5-10 parts sebacic acid, 50-70 parts acrylic acid, 10-20 parts olivine powder, 10-20 parts magnesium aluminum silicate, 20-30 parts calcium acrylate, 1-2 parts aluminate coupling agent, 1-2 parts curing agent, 1-2 parts accelerator, 1-2 parts water-reducing agent, 1-2 parts modifying agent, 30-40 parts deionized water, and 0.5-1 parts ammonium persulfate. The preparation method of the modifying agent is as follows:

[0008] Step S1: Under stirring conditions at 80-90℃, 2-(diethoxyphosphoryl)-2,2-difluoroacetic acid, 5,6-epoxyhexyltriethoxysilane, and triphenylphosphine were added to anhydrous ethanol. After reacting for 2-3 hours, the mixture was cooled to room temperature and purified to obtain intermediate 1. The structural formula of intermediate 1 is as follows: ;

[0009] Step S2: Under stirring conditions at 100-110℃, intermediates 1, 2-aminododecanoic acid, and p-toluenesulfonic acid are added to toluene. After reacting for 5.5-6.5 hours, the mixture is cooled to room temperature and purified to obtain intermediate 2. The structural formula of intermediate 2 is as follows:

[0010] ;

[0011] Step S3: Under acidic conditions at 50-60℃, intermediate 2, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide, and citric acid are added to N,N-dimethylformamide. After stirring and reacting for 6-7 hours, the mixture is cooled to room temperature and purified to obtain the modified additive.

[0012] The synthetic route for intermediate 2 is as follows:

[0013] .

[0014] Further, in step S1, the molar ratio of 2-(diethoxyphosphoryl)-2,2-difluoroacetic acid, 5,6-epoxyhexyltriethoxysilane, and triphenylphosphine is 1:0.9-1.1:0.01-0.02, and the amount of 2-(diethoxyphosphoryl)-2,2-difluoroacetic acid added to anhydrous ethanol is 0.06-0.08 g / mL.

[0015] Further, in step S2, the molar ratio of intermediate 1, 2-aminododecanoic acid and p-toluenesulfonic acid is 1:0.9-1:0.01-0.02, and the amount of 2-aminododecanoic acid added to toluene is 0.04-0.05 g / mL.

[0016] Further, in step S3, the molar ratio of intermediate 2, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide and citric acid is 3:0.85-1:6-6.5, and the amount of citric acid added to N,N-dimethylformamide is 0.05-0.06 g / mL.

[0017] Furthermore, the curing agent is selected from one or more of 2-butanone peroxide, m-phenylenediamine, and 4,4'-diaminodiphenyl sulfone.

[0018] Furthermore, the coagulant is water glass or aluminum sulfate.

[0019] Furthermore, the water-reducing agent is a polycarboxylate water-reducing agent.

[0020] Furthermore, the aluminate coupling agent is distearyloxyisopropyl aluminate.

[0021] This invention also provides a method for preparing nanomaterials for sealing the cavity of cable trenches in walls, comprising the following steps:

[0022] (1) Grind olivine powder, magnesium aluminum silicate and calcium acrylate into a ball mill, then add some deionized water and mix evenly to obtain a mixture;

[0023] (2) Sebacic acid, acrylic acid, aluminate coupling agent, curing agent, coagulant, water-reducing agent, modifier, ammonium persulfate and remaining deionized water are added to the mixture obtained in step (1) to react and obtain nanomaterials for sealing the cavity of the cable trench in the wall.

[0024] The present invention has the following beneficial effects:

[0025] This invention prepares a modifying agent through chemical modification. First, intermediate 1 is obtained by ring-opening reaction of the carboxyl group of 2-(diethoxyphosphoryl)-2,2-difluoroacetic acid with the epoxy group of 5,6-epoxyhexyltriethoxysilane. Then, intermediate 2 is obtained by esterification reaction of the hydroxyl group of intermediate 1 with the carboxyl group of 2-aminododecanoic acid. Finally, the modified agent is obtained by amidation reaction of the amino group of intermediate 2 with the carboxyl group of citric acid. The modified agent contains phosphorus, fluorine, silicon and long-chain alkyl elements in its molecular structure. The siloxy and carboxyl groups in the modified agent can react with active groups such as hydroxyl groups on the surface of materials such as magnesium aluminum silicate, thereby achieving connection with materials such as magnesium aluminum silicate. This makes the various components of the nanomaterial system for sealing the cavity of the cable trench in the wall more tightly connected and form a whole. The introduction of inorganic substances such as magnesium aluminum silicate can form a three-dimensional network skeleton in the nanomaterials used for sealing the cavity of cable trenches in walls, resisting external stress, reducing the risk of material shrinkage and cracking, and effectively enhancing the compressive strength of the nanomaterials used for sealing the cavity of cable trenches in walls.

[0026] The introduction of phosphorus into the molecular structure of modifying additives can improve the flame retardancy of materials. Under heating, phosphorus-containing compounds decompose to generate substances such as phosphoric acid and metaphosphoric acid. These substances have a strong dehydrating effect, forming a carbonized layer on the material surface. This carbonized layer is a poor conductor of heat, blocking heat transfer and thus achieving flame retardancy. This protects the safety of cables and other equipment in cable trenches and prevents the failure of water-stopping materials due to fire. The introduction of fluorine can improve the hydrophobicity and chemical stability of materials. Fluorides have high chemical bond energies and are not easily broken by other chemicals, allowing the material to maintain stable performance under different environmental conditions, such as acidic and alkaline environments, extending the material's service life. In addition, fluorine has extremely high electronegativity. Introducing it into modifying additives and then using the modified additives as raw materials significantly reduces the surface energy of nanomaterials for sealing cable trench cavities, thus achieving superhydrophobicity. This significantly enhances the material's anti-permeability performance and reduces the risk of moisture penetrating into the cable trench. The introduction of silicon can significantly enhance the mechanical strength, chemical stability, and flame retardancy of materials. Silicon atoms exist in the modifying agent in the form of silicon-oxygen bonds. These strong bonds provide a robust framework for the nanomaterials used in sealing cable trench cavities in walls. This structure enhances the material's hardness and compressive strength, allowing it to maintain structural integrity and sealing performance even under pressure and deformation from the cable trench. Furthermore, silicon-oxygen bonds possess high chemical stability, resisting the erosion of various chemicals. When silicon is present in the nanomaterial, the silicon-oxygen structure formed on its surface acts as a barrier, preventing corrosive substances such as acids and alkalis from reacting with the material's internal components. This ensures the sealing nanomaterials maintain stable performance and extend their service life when facing acidic or alkaline substances that may be present in the cable trench. In addition, silicon promotes the formation of a char layer during combustion. When heated, silicon atoms interact with other atoms in the material, altering the molecular chain breakage pattern and reaction pathway, resulting in more carbon remaining on the material surface to form a char layer. This char layer has excellent thermal insulation properties, further blocking heat transfer and slowing down the material's thermal degradation rate, thereby improving its flame-retardant properties. Furthermore, phosphorus and silicon can work synergistically to improve the flame retardant properties of materials, enabling them to maintain good performance in high-temperature environments. The introduction of long-chain alkyl groups can improve the dispersibility and hydrophobicity of materials. Due to their longer carbon chain structure, long-chain alkyl groups form a "barrier" around the particles when attached to the particle surface. This steric hindrance increases the distance between particles, thereby reducing their interaction and agglomeration tendency. This physical barrier helps improve particle dispersibility in the medium, preventing particle agglomeration and sedimentation, thus ensuring that material performance is not affected. Moreover, the presence of long-chain alkyl groups reduces the surface free energy of the material, increasing the contact angle of water on the material surface, thus achieving a hydrophobic effect and effectively preventing moisture from penetrating into the cable trench cavity.Therefore, the introduction of phosphorus, fluorine, silicon and long-chain alkyl elements can endow the modified additives with multifunctionality. Introducing the modified additives into the nanomaterials for sealing the cavity of cable trenches in walls can not only reduce the agglomeration and sedimentation of particles in the system, but also significantly enhance the flame retardancy, hydrophobicity, chemical stability and compressive strength of the nanomaterials.

[0027] This invention combines raw materials such as sebacic acid, acrylic acid, olivine powder, magnesium aluminum silicate, calcium acrylate, aluminate coupling agent, curing agent, accelerator, water-reducing agent, and modifying agent to obtain a nanomaterial for sealing the cavity of cable trench in walls. The modifying agent and raw materials such as magnesium aluminum silicate have a synergistic effect, which can not only improve the compressive strength, flame retardant properties, hydrophobic properties and chemical stability of the material, but also ensure the reliability and long-term durability of the water-sealing nanomaterial in complex environments, thereby effectively meeting the safety and service life requirements in practical applications. Detailed Implementation

[0028] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the embodiments of this application. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0029] All raw materials used in the following examples are commercially available products. The olivine powder is magnesium olivine powder, with an MgO content of 57%, a SiO2 content of 43%, and a particle size of 325 mesh, purchased from Lingshou County Erping Mineral Products Processing Plant; the magnesium aluminum silicate has a density of 2.3 g / cm³. 3 The particle size was 325 mesh, purchased from Shijiazhuang Hualang Mineral Products Trading Co., Ltd.; the calcium acrylate content was ≥99.5%, and the moisture content was ≤0.5%, purchased from Hubei Xinghengye Technology Co., Ltd.; the water glass effective component content was 99%, and the density was 1.362 g / mL, purchased from Jinan Huisheng Chemical Co., Ltd.; the polycarboxylate superplasticizer had a measured water reduction rate of 31.2% and a measured water bleeding rate of 52%, purchased from Jinan Yanglan New Material Technology Co., Ltd. Example 1

[0030] A nanomaterial for sealing the cavity of a cable trench in a wall comprises the following raw materials in parts by weight: 5 parts sebacic acid, 50 parts acrylic acid, 10 parts olivine powder, 10 parts magnesium aluminum silicate, 20 parts calcium acrylate, 1 part aluminate coupling agent, 1 part curing agent, 1 part accelerator, 1 part water-reducing agent, 1 part modifier, 30 parts deionized water, and 0.5 parts ammonium persulfate.

[0031] The curing agent is 2-butanone peroxide, the accelerator is water glass, the water-reducing agent is polycarboxylate water-reducing agent, and the aluminate coupling agent is distearyloxyisopropyl aluminate.

[0032] The preparation method of the modified additive is as follows:

[0033] Step S1: 2-(diethoxyphosphoryl)-2,2-difluoroacetic acid, 5,6-epoxyhexyltriethoxysilane, and triphenylphosphine were added to anhydrous ethanol at 80°C with stirring. After reacting for 3 hours, the mixture was cooled to room temperature and filtered to obtain a filtrate. Then, the anhydrous ethanol was removed by rotary evaporation of the filtrate at 40°C to obtain intermediate 1, wherein the molar ratio of 2-(diethoxyphosphoryl)-2,2-difluoroacetic acid, 5,6-epoxyhexyltriethoxysilane, and triphenylphosphine was 1:0.9:0.01, and the amount of 2-(diethoxyphosphoryl)-2,2-difluoroacetic acid added to the anhydrous ethanol was 0.06 g / mL.

[0034] Step S2: At 100℃ and under stirring, intermediates 1, 2-aminododecanoic acid and p-toluenesulfonic acid were added to toluene. After reacting for 6.5 h, the mixture was cooled to room temperature and filtered to obtain a filtrate. Then, the toluene was removed by rotary evaporation of the filtrate at 60℃ to obtain intermediate 2. The molar ratio of intermediates 1, 2-aminododecanoic acid and p-toluenesulfonic acid was 1:0.9:0.01, and the amount of 2-aminododecanoic acid added to toluene was 0.04 g / mL.

[0035] Step S3: At 50℃, intermediate 2, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide, and citric acid were added to N,N-dimethylformamide. The pH was adjusted to 4.5-6 with 0.1 M HCl solution. After stirring for 7 hours, the mixture was cooled to room temperature and then extracted sequentially with the same volume of deionized water as N,N-dimethylformamide and twice the volume of ethyl acetate. The organic phase was then distilled under reduced pressure to obtain the modified auxiliary agent. The molar ratio of intermediate 2, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide, and citric acid was 3:0.85:6, and the amount of citric acid added to N,N-dimethylformamide was 0.05 g / mL.

[0036] The synthetic route for intermediate 2 is as follows:

[0037] ;

[0038] .

[0039] The NMR results for intermediate 1 are as follows: 1H NMR (300MHz, acetone-d6) δ 5.37 (s, 1H), 4.08-4.36 (m, 7H), 3.79-3.88 (m, 6H), 1.20-1.41 (m, 21H), 0.51-0.60 (m, 2H).

[0040] The NMR results for intermediate 2 are as follows: 1H NMR (300MHz, acetone-d6) δ 8.76 (s, 2H), 5.16 (m, 1H), 4.16-4.42 (m, 6H), 3.76-3.85 (m, 6H), 3.36 (t, 1H), 1.88 (d, 2H), 1.49 (d, 2H), 1.21-1.36 (m, 35H), 0.88 (t, 3H), 0.56 (t, 2H).

[0041] This invention also provides a method for preparing nanomaterials for sealing the cavity of cable trenches in walls, comprising the following steps:

[0042] (1) Grind olivine powder, magnesium aluminum silicate and calcium acrylate into a ball mill, then add 20 parts of deionized water and mix evenly to obtain a mixture. The ball-to-material ratio during ball milling is 15:1, the rotation speed is 600 r / min, the ball milling time is 10 h, and zirconia balls are selected. The diameter of the small ball is 1 mm, the diameter of the medium ball is 3 mm, the diameter of the large ball is 5 mm, and the ratio of large, medium and small balls is 4:4:2.

[0043] (2) Sebacic acid, acrylic acid, aluminate coupling agent, curing agent, coagulant, water-reducing agent, modifying agent, ammonium persulfate and remaining deionized water are added to the mixture obtained in step (1). The pH value is adjusted to 3.5-4.5 with 0.1 M HCl solution and stirred and polymerized at 60℃ for 2 hours to obtain nanomaterials for sealing the cavity of cable trench in wall. The average particle size of the nanomaterials for sealing the cavity of cable trench in wall is measured to be 82.6 nm using a laser particle size analyzer. Example 2

[0044] A nanomaterial for sealing the cavity of a cable trench in a wall comprises the following raw materials in parts by weight: 10 parts sebacic acid, 70 parts acrylic acid, 20 parts olivine powder, 20 parts magnesium aluminum silicate, 30 parts calcium acrylate, 2 parts aluminate coupling agent, 2 parts curing agent, 2 parts accelerator, 2 parts water-reducing agent, 2 parts modifier, 40 parts deionized water, and 1 part ammonium persulfate.

[0045] The curing agent is m-phenylenediamine, the accelerator is aluminum sulfate, the water-reducing agent is polycarboxylate water-reducing agent, and the aluminate coupling agent is distearyloxyisopropyl aluminate.

[0046] The preparation method of the modified additive is as follows:

[0047] Step S1: 2-(diethoxyphosphoryl)-2,2-difluoroacetic acid, 5,6-epoxyhexyltriethoxysilane, and triphenylphosphine were added to anhydrous ethanol at 90°C with stirring. After reacting for 2 hours, the mixture was cooled to room temperature and filtered to obtain a filtrate. Then, the anhydrous ethanol was removed by rotary evaporation of the filtrate at 40°C to obtain intermediate 1, wherein the molar ratio of 2-(diethoxyphosphoryl)-2,2-difluoroacetic acid, 5,6-epoxyhexyltriethoxysilane, and triphenylphosphine was 1:1.1:0.02, and the amount of 2-(diethoxyphosphoryl)-2,2-difluoroacetic acid added to the anhydrous ethanol was 0.08 g / mL.

[0048] Step S2: At 110℃ and under stirring, intermediates 1, 2-aminododecanoic acid and p-toluenesulfonic acid were added to toluene. After reacting for 5.5 h, the mixture was cooled to room temperature and filtered to obtain a filtrate. Then, the toluene was removed by rotary evaporation of the filtrate at 60℃ to obtain intermediate 2. The molar ratio of intermediates 1, 2-aminododecanoic acid and p-toluenesulfonic acid was 1:1:0.02, and the amount of 2-aminododecanoic acid added to toluene was 0.05 g / mL.

[0049] Step S3: At 60℃, intermediate 2, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide, and citric acid were added to N,N-dimethylformamide. The pH was adjusted to 4.5-6 with 0.1 M HCl solution. After stirring for 6 hours, the mixture was cooled to room temperature and then extracted sequentially with the same volume of deionized water as N,N-dimethylformamide and twice the volume of ethyl acetate. The organic phase was then distilled under reduced pressure to obtain the modified auxiliary agent. The molar ratio of intermediate 2, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide, and citric acid was 3:1:6.5, and the amount of citric acid added to N,N-dimethylformamide was 0.06 g / mL.

[0050] This invention also provides a method for preparing nanomaterials for sealing the cavity of cable trenches in walls, comprising the following steps:

[0051] (1) Grind olivine powder, magnesium aluminum silicate and calcium acrylate into a ball mill, then add 25 parts of deionized water and mix evenly to obtain a mixture. The ball-to-material ratio during ball milling is 15:1, the rotation speed is 600 r / min, the ball milling time is 10 h, and zirconia balls are selected. The diameter of the small ball is 1 mm, the diameter of the medium ball is 3 mm, the diameter of the large ball is 5 mm, and the ratio of large, medium and small balls is 4:4:2.

[0052] (2) Sebacic acid, acrylic acid, aluminate coupling agent, curing agent, coagulant, water-reducing agent, modifying agent, ammonium persulfate and remaining deionized water are added to the mixture obtained in step (1). The pH value is adjusted to 3.5-4.5 with 0.1 M HCl solution and stirred and polymerized at 60℃ for 3 hours to obtain nanomaterials for sealing the cavity of cable trench in wall. The average particle size of the nanomaterials for sealing the cavity of cable trench in wall is measured to be 87.1 nm using a laser particle size analyzer. Example 3

[0053] A nanomaterial for sealing the cavity of a cable trench in a wall comprises the following raw materials in parts by weight: 8 parts sebacic acid, 60 parts acrylic acid, 15 parts olivine powder, 15 parts magnesium aluminum silicate, 25 parts calcium acrylate, 1.5 parts aluminate coupling agent, 1.5 parts curing agent, 1.5 parts accelerator, 1.5 parts water-reducing agent, 1.5 parts modifying agent, 35 parts deionized water, and 0.8 parts ammonium persulfate.

[0054] The curing agent is 4,4'-diaminodiphenyl sulfone, the coagulating agent is aluminum sulfate, the water-reducing agent is polycarboxylate water-reducing agent, and the aluminate coupling agent is distearyloxyisopropyl aluminate.

[0055] The preparation method of the modified additive is as follows:

[0056] Step S1: 2-(diethoxyphosphoryl)-2,2-difluoroacetic acid, 5,6-epoxyhexyltriethoxysilane, and triphenylphosphine were added to anhydrous ethanol at 85°C with stirring. After reacting for 2.5 h, the mixture was cooled to room temperature and filtered to obtain a filtrate. Then, the anhydrous ethanol was removed by rotary evaporation of the filtrate at 40°C to obtain intermediate 1, wherein the molar ratio of 2-(diethoxyphosphoryl)-2,2-difluoroacetic acid, 5,6-epoxyhexyltriethoxysilane, and triphenylphosphine was 1:1:0.015, and the amount of 2-(diethoxyphosphoryl)-2,2-difluoroacetic acid added to the anhydrous ethanol was 0.07 g / mL.

[0057] Step S2: At 105℃ and under stirring, intermediates 1, 2-aminododecanoic acid and p-toluenesulfonic acid were added to toluene. After reacting for 6 hours, the mixture was cooled to room temperature and filtered to obtain a filtrate. Then, the toluene was removed by rotary evaporation of the filtrate at 60℃ to obtain intermediate 2. The molar ratio of intermediates 1, 2-aminododecanoic acid and p-toluenesulfonic acid was 1:0.95:0.015, and the amount of 2-aminododecanoic acid added to toluene was 0.045 g / mL.

[0058] Step S3: At 55℃, intermediate 2, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide, and citric acid were added to N,N-dimethylformamide. The pH was adjusted to 4.5-6 with 0.1 M HCl solution. After stirring for 6.5 h, the mixture was cooled to room temperature and then extracted sequentially with the same volume of deionized water as N,N-dimethylformamide and twice the volume of ethyl acetate. The organic phase was then distilled under reduced pressure to obtain the modified auxiliary agent. The molar ratio of intermediate 2, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide, and citric acid was 3:0.9:6.2, and the amount of citric acid added to N,N-dimethylformamide was 0.055 g / mL.

[0059] This invention also provides a method for preparing nanomaterials for sealing the cavity of cable trenches in walls, comprising the following steps:

[0060] (1) Grind olivine powder, magnesium aluminum silicate and calcium acrylate into a ball mill, then add 23 parts of deionized water and mix evenly to obtain a mixture. The ball-to-material ratio during ball milling is 15:1, the rotation speed is 600 r / min, the ball milling time is 10 h, and zirconia balls are selected. The diameter of the small ball is 1 mm, the diameter of the medium ball is 3 mm, the diameter of the large ball is 5 mm, and the ratio of large, medium and small balls is 4:4:2.

[0061] (2) Sebacic acid, acrylic acid, aluminate coupling agent, curing agent, coagulant, water-reducing agent, modifying agent, ammonium persulfate and remaining deionized water are added to the mixture obtained in step (1). The pH value is adjusted to 3.5-4.5 with 0.1 M HCl solution and stirred and polymerized at 60℃ for 2.5h to obtain nanomaterials for sealing the cavity of cable trench in wall. The average particle size of the nanomaterials for sealing the cavity of cable trench in wall is measured to be 81.9nm using a laser particle size analyzer. Comparative Example 1

[0062] A nanomaterial for sealing the cavity of a cable trench in a wall comprises the following raw materials in parts by weight: 8 parts sebacic acid, 40 parts acrylic acid, 10 parts olivine powder, 10 parts magnesium aluminum silicate, 10 parts calcium acrylate, 0.5 parts aluminate coupling agent, 1.5 parts curing agent, 1.5 parts accelerator, 0.5 parts water-reducing agent, 0.5 parts modifying agent, 35 parts deionized water, and 0.8 parts ammonium persulfate;

[0063] The curing agent is 4,4'-diaminodiphenyl sulfone, the coagulating agent is aluminum sulfate, the water-reducing agent is polycarboxylate water-reducing agent, and the aluminate coupling agent is distearyloxyisopropyl aluminate.

[0064] The preparation method of the modified additive is as follows:

[0065] Step S1: 2-(diethoxyphosphoryl)-2,2-difluoroacetic acid, 5,6-epoxyhexyltriethoxysilane, and triphenylphosphine were added to anhydrous ethanol at 70°C with stirring. After reacting for 1 hour, the mixture was cooled to room temperature and filtered to obtain a filtrate. Then, the filtrate was rotary evaporated at 40°C to remove the anhydrous ethanol, yielding intermediate 1. The molar ratio of 2-(diethoxyphosphoryl)-2,2-difluoroacetic acid, 5,6-epoxyhexyltriethoxysilane, and triphenylphosphine was 1:0.5:0.005, and the amount of 2-(diethoxyphosphoryl)-2,2-difluoroacetic acid added to the anhydrous ethanol was 0.07 g / mL.

[0066] Step S2: At 80°C and under stirring, intermediates 1, 2-aminododecanoic acid and p-toluenesulfonic acid were added to toluene. After reacting for 6 hours, the mixture was cooled to room temperature and filtered to obtain a filtrate. Then, the toluene was removed by rotary evaporation of the filtrate at 60°C to obtain intermediate 2. The molar ratio of intermediates 1, 2-aminododecanoic acid and p-toluenesulfonic acid was 1:0.8:0.015, and the amount of 2-aminododecanoic acid added to the toluene was 0.045 g / mL.

[0067] Step S3: At 55℃, intermediate 2, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide, and citric acid were added to N,N-dimethylformamide. The pH was adjusted to 4.5-6 with 0.1 M HCl solution. After stirring for 6.5 h, the mixture was cooled to room temperature and then extracted sequentially with the same volume of deionized water as N,N-dimethylformamide and twice the volume of ethyl acetate. The organic phase was then distilled under reduced pressure to obtain the modified auxiliary agent. The molar ratio of intermediate 2, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide, and citric acid was 1:0.9:2, and the amount of citric acid added to N,N-dimethylformamide was 0.055 g / mL.

[0068] This invention also provides a method for preparing nanomaterials for sealing the cavity of cable trenches in walls, comprising the following steps:

[0069] (1) Grind olivine powder, magnesium aluminum silicate and calcium acrylate into a ball mill, then add 25 parts of deionized water and mix evenly to obtain a mixture. The ball-to-material ratio during ball milling is 15:1, the rotation speed is 600 r / min, the ball milling time is 7 h, and zirconia balls are selected. The diameter of the small ball is 1 mm, the diameter of the medium ball is 3 mm, the diameter of the large ball is 5 mm, and the ratio of large, medium and small balls is 4:4:2.

[0070] (2) Sebacic acid, acrylic acid, aluminate coupling agent, curing agent, coagulant, water-reducing agent, modifying agent, ammonium persulfate and remaining deionized water are added to the mixture obtained in step (1). The pH value is adjusted to 3.5-4.5 with 0.1 M HCl solution and stirred and polymerized at 60℃ for 2.5h to obtain nanomaterials for sealing the cavity of cable trench in wall. The average particle size of the nanomaterials for sealing the cavity of cable trench in wall is measured to be 101.5nm using a laser particle size analyzer. Comparative Example 2

[0071] A nanomaterial for sealing the cavity of a cable trench in a wall comprises the following raw materials in parts by weight: 8 parts sebacic acid, 60 parts acrylic acid, 15 parts olivine powder, 15 parts magnesium aluminum silicate, 25 parts calcium acrylate, 1.5 parts aluminate coupling agent, 1.5 parts curing agent, 1.5 parts accelerator, 1.5 parts water-reducing agent, 1.5 parts modifying agent, 35 parts deionized water, and 0.8 parts ammonium persulfate.

[0072] The curing agent is 4,4'-diaminodiphenyl sulfone, the coagulating agent is aluminum sulfate, the water-reducing agent is polycarboxylate water-reducing agent, and the aluminate coupling agent is distearyloxyisopropyl aluminate.

[0073] The preparation method of the modified additive is as follows:

[0074] Step S1: 2-(diethoxyphosphoryl)-2,2-difluoroacetic acid, 5,6-epoxyhexyltriethoxysilane, and triphenylphosphine were added to anhydrous ethanol at 85°C with stirring. After reacting for 2.5 h, the mixture was cooled to room temperature and filtered to obtain a filtrate. Then, the anhydrous ethanol was removed by rotary evaporation of the filtrate at 40°C to obtain an intermediate. The molar ratio of 2-(diethoxyphosphoryl)-2,2-difluoroacetic acid, 5,6-epoxyhexyltriethoxysilane, and triphenylphosphine was 1:1:0.015, and the amount of 2-(diethoxyphosphoryl)-2,2-difluoroacetic acid added to the anhydrous ethanol was 0.07 g / mL.

[0075] Step S2: At 105℃ and under stirring, the intermediate, 2-aminododecanoic acid and p-toluenesulfonic acid are added to toluene. After reacting for 6 hours, the mixture is cooled to room temperature and filtered to obtain a filtrate. Then, the toluene is removed by rotary evaporation of the filtrate at 60℃ to obtain the modified additive. The molar ratio of the intermediate, 2-aminododecanoic acid and p-toluenesulfonic acid is 1:0.95:0.015, and the amount of 2-aminododecanoic acid added to the toluene is 0.045 g / mL.

[0076] This invention also provides a method for preparing nanomaterials for sealing the cavity of cable trenches in walls, comprising the following steps:

[0077] (1) Grind olivine powder, magnesium aluminum silicate and calcium acrylate into a ball mill, then add 25 parts of deionized water and mix evenly to obtain a mixture. The ball-to-material ratio during ball milling is 15:1, the rotation speed is 600 r / min, the ball milling time is 7 h, and zirconia balls are selected. The diameter of the small ball is 1 mm, the diameter of the medium ball is 3 mm, the diameter of the large ball is 5 mm, and the ratio of large, medium and small balls is 4:4:2.

[0078] (2) Sebacic acid, acrylic acid, aluminate coupling agent, curing agent, coagulant, water-reducing agent, modifying agent, ammonium persulfate and remaining deionized water are added to the mixture obtained in step (1). The pH value is adjusted to 3.5-4.5 with 0.1 M HCl solution and stirred and polymerized at 60℃ for 2.5h to obtain nanomaterials for sealing the cavity of cable trench in wall. The average particle size of the nanomaterials for sealing the cavity of cable trench in wall is measured to be 110.7nm using a laser particle size analyzer. Comparative Example 3

[0079] A nanomaterial for sealing the cavity of a cable trench in a wall comprises the following raw materials in parts by weight: 8 parts sebacic acid, 60 parts acrylic acid, 15 parts olivine powder, 15 parts magnesium aluminum silicate, 25 parts calcium acrylate, 1.5 parts aluminate coupling agent, 1.5 parts curing agent, 1.5 parts accelerator, 1.5 parts water-reducing agent, 35 parts deionized water, and 0.8 parts ammonium persulfate.

[0080] The curing agent is 4,4'-diaminodiphenyl sulfone, the coagulating agent is aluminum sulfate, the water-reducing agent is polycarboxylate water-reducing agent, and the aluminate coupling agent is distearyloxyisopropyl aluminate.

[0081] This invention also provides a method for preparing nanomaterials for sealing the cavity of cable trenches in walls, comprising the following steps:

[0082] (1) Grind olivine powder, magnesium aluminum silicate and calcium acrylate into a ball mill, then add 25 parts of deionized water and mix evenly to obtain a mixture. The ball-to-material ratio during ball milling is 15:1, the rotation speed is 600 r / min, the ball milling time is 7 h, and zirconia balls are selected. The diameter of the small ball is 1 mm, the diameter of the medium ball is 3 mm, the diameter of the large ball is 5 mm, and the ratio of large, medium and small balls is 4:4:2.

[0083] (2) Sebacic acid, acrylic acid, aluminate coupling agent, curing agent, coagulant, water-reducing agent, ammonium persulfate and remaining deionized water are added to the mixture obtained in step (1). The pH value is adjusted to 3.5-4.5 with 0.1 M HCl solution. The mixture is stirred and polymerized at 60℃ for 2.5h to obtain nanomaterials for sealing the cavity of cable trench in wall. The average particle size of the nanomaterials for sealing the cavity of cable trench in wall is measured to be 111.2nm using a laser particle size analyzer.

[0084] Compressive strength test: The water-stopping material for the cable trench cavity in the wall was made into a cylindrical specimen with a diameter of 40 mm and a height of 100 mm using nanomaterials. The compressive strength test method of the solid sand body in JC / T 2037-2010 "Acrylic Grouting Materials" was used.

[0085] Permeability Coefficient Test: According to the requirements for permeability coefficient in JC / T 2037-2010 "Acrylic Grouting Materials", the permeability test method in GB / T 50123-1999 "Standard for Civil Engineering Testing Methods" was adopted. The permeability coefficient test consisted of six specimens per group. The prepared nanomaterial grout for sealing the cable trench cavity in the wall was poured into a ring cutter, allowing the grout to solidify within the ring cutter. After standing for 1 day, the ring cutter containing the solidified material was installed in a permeation container, and the permeability test was conducted according to the variable head permeability test method. Before conducting the permeability test, the ring cutter containing the solidified material should be wrapped with plastic wrap to prevent the solidified material from drying and shrinking.

[0086] Flame retardancy test: According to the requirements for combustion performance testing in GB 8624-2012 "Classification of Combustion Performance of Building Materials and Products", the combustion performance rating of the test specimens is evaluated using GB / T 5464-2010 "Test Method for Non-combustibility of Building Materials", GB / T 14402-2007 "Determination of Combustion Performance and Calorific Value of Building Materials and Products" and GB / T 20284-2006 "Single Combustion Test of Building Materials or Products".

[0087] Durability test: First, a cube with a side length of 40mm was made of nanomaterial to seal the water-stopping cavity of the cable trench in the wall. After standing for 1 day, the test specimens were obtained. Each specimen was then immersed in a 10% sodium hydroxide solution and a 1% hydrochloric acid solution for 72 hours, respectively. After that, the specimens were removed, and the appearance of powdering or cracks on their surface was observed and recorded.

[0088] The specific test data can be found in Table 1.

[0089] Table 1 Performance Test Results:

[0090]

[0091] According to the data in Table 1, the nanomaterials for sealing cable trench cavities in Examples 1-3 are superior to those in Comparative Examples 1-3 in terms of compressive strength and permeability coefficient. This indicates that adjusting the proportions of raw materials and introducing modifying agents can significantly improve the compressive strength and water resistance of the materials, thereby effectively preventing structural damage and electrical faults and ensuring long-term stability of the sealing effect. Regarding acid and alkali resistance, the nanomaterials for sealing cable trench cavities in Examples 1-3 are stable in acidic and alkaline environments, without powdering or cracking, while the materials in Comparative Examples 1-3 exhibit these changes. This shows that the introduction of modifying agents can enhance the environmental stability of the materials and extend their service life. In terms of combustion performance, the materials in Examples 1-3 achieve an A1 rating, effectively preventing the spread of fire in a fire. In contrast, the materials in Comparative Examples 1-3 have poorer combustion performance, increasing the fire risk. Therefore, the nanomaterials prepared by adjusting the proportions of raw materials and introducing modifying agents also demonstrate better safety.

[0092] Although embodiments of this application have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A nanomaterial for sealing a wall cable trench cavity, characterized by, The raw materials include the following components in parts by weight: sebacic acid 5-10 parts, acrylic acid 50-70 parts, olivine powder 10-20 parts, magnesium aluminum silicate 10-20 parts, calcium acrylate 20-30 parts, aluminum ester coupling agent 1-2 parts, curing agent 1-2 parts, coagulant 1-2 parts, water reducing agent 1-2 parts, modified additive 1-2 parts, deionized water 30-40 parts, ammonium persulfate 0.5-1 part, and the modified additive is prepared by the following method: Step S1, 2-(diethoxy phosphoryl)-2,2-difluoroacetic acid, 5,6-epoxyhexyl triethoxysilane and triphenylphosphine are added to anhydrous ethanol under stirring at 80-90℃, and after reaction for 2-3h, the mixture is cooled to room temperature, purified to obtain intermediate 1; Step S2, intermediate 1, 2-aminododecanoic acid and p-toluenesulfonic acid are added to toluene under stirring at 100-110℃, and after reaction for 5.5-6.5h, the mixture is cooled to room temperature, purified to obtain intermediate 2; Step S3, intermediate 2, 1-(3-dimethylaminopropyl)-3-ethyl carbodiimide and citric acid are added to N,N-dimethylformamide under stirring at 50-60℃, and after reaction for 6-7h, the mixture is cooled to room temperature, extracted with deionized water, N,N-dimethylformamide and ethyl acetate, and the organic phase is distilled under reduced pressure to obtain the modified additive; The synthetic route of intermediate 2 is as follows: ； ； In step S1, the molar ratio of 2-(diethoxy phosphoryl)-2,2-difluoroacetic acid, 5,6-epoxyhexyl triethoxysilane and triphenylphosphine is 1:0.9-1.1:0.01-0.02, and the addition amount of 2-(diethoxy phosphoryl)-2,2-difluoroacetic acid in anhydrous ethanol is 0.06-0.08g / mL; In step S2, the molar ratio of intermediate 1, 2-aminododecanoic acid and p-toluenesulfonic acid is 1:0.9-1:0.01-0.02, and the addition amount of 2-aminododecanoic acid in toluene is 0.04-0.05g / mL; In step S3, the molar ratio of intermediate 2, 1-(3-dimethylaminopropyl)-3-ethyl carbodiimide and citric acid is 3:0.85-1:6-6.5, and the addition amount of citric acid in N,N-dimethylformamide is 0.05-0.06g / mL.

2. The nanomaterial for sealing a wall cable trench cavity according to claim 1, characterized in that, The curing agent is selected from one or more of 2-peroxide butanone, m-phenylenediamine and 4,4'-diaminodiphenyl sulfone.

3. The nanomaterial for sealing a wall cable trench cavity according to claim 1, wherein, The coagulant is water glass or aluminum sulfate.

4. The nanomaterial for sealing a wall cable trench cavity according to claim 1, wherein, The water reducing agent is polycarboxylic acid water reducing agent.

5. The nanomaterial for sealing a wall cable trench cavity according to claim 1, wherein, The aluminum ester coupling agent is isopropyl di-stearoyl oxy aluminate.

6. The method for preparing nanomaterials for sealing cable trench cavities in walls according to any one of claims 1-5, characterized in that, The method comprises the following steps: (1) olivine powder, magnesium aluminum silicate and calcium acrylate are ball milled, and then mixed with part of deionized water to obtain a mixture; (2) sebacic acid, acrylic acid, aluminum ester coupling agent, curing agent, coagulant, water reducing agent, modified additive, ammonium persulfate and the remaining deionized water are added to the mixture obtained in step (1) and reacted for 2-3h to obtain a nanometer material for wall cable trench cavity water stop.

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