Grouting material for blocking fluid with strong osmotic pressure and preparation method of grouting material

Abstract

The invention relates to the field of grouting materials, in particular to a grouting material for blocking fluid with strong osmotic pressure and a preparation method of the grouting material, and the grouting material comprises the following raw materials: 20-40 parts of a component A, 30-50 parts of a component B and 20-40 parts of a component C, the component A is modified resin microspheres; the component B comprises the following components in parts by weight: 50-70 parts of epoxy resin, 10-20 parts of a reactive diluent and 5-10 parts of an anti-dispersing agent; and the component C comprises the following components in parts by weight: 40-60 parts of an amine curing agent, 2-5 parts of an accelerant and 10-20 parts of a toughening agent. According to the grouting material, the modified resin microspheres with the three-layer structure serve as core components, and multi-scale plugging of cracks is achieved through function division and cooperation of different layers.

Description

Technical Field

[0001] This invention relates to the field of grouting materials, and more specifically, to a grouting material for blocking fluids with strong osmotic pressure and its preparation method. Background Technology

[0002] As underground engineering projects such as transportation tunnels, mining operations, and hydropower dam foundations in my country expand to deeper levels, the hydrogeological conditions faced by these projects are becoming increasingly complex. Sudden water inrushes with high osmotic pressure (>2MPa), large flow rates (>100m³ / h), and high flow velocities (>1m / s) have become a key challenge restricting the safe construction and operation of these projects.

[0003] Currently, grouting and sealing materials used in high-osmotic-pressure environments are mainly divided into three categories: cement-based materials, chemical grouts, and expanding polymer materials. However, all three types of materials have insurmountable technical defects and cannot fully meet the sealing requirements in complex dynamic water environments.

[0004] Cement-based materials (such as the dynamic water anti-dispersion grouting material disclosed in patent CN119797865A) are based on ordinary Portland cement, with anti-dispersion agents added to improve their retention rate in dynamic water. Although these materials are inexpensive and widely available, they are essentially granular grouts with relatively large particle sizes, making them difficult to inject into micro-cracks with a width of less than 0.1 mm, severely limiting their injectability. Furthermore, their strength development is slow (28-day compressive strength > 15 MPa), making them prone to secondary damage under high-pressure dynamic water erosion, thus hindering long-term sealing.

[0005] Chemical grouting materials (represented by low-viscosity polymers such as epoxy resin, polyurethane, and acrylates) are widely used for sealing micro-cracks due to their excellent injectability and permeability. For example, low-viscosity epoxy resin has an injectability permeability coefficient K ≥ 10⁻ 6 Micro-cracks at cm / s result in high mechanical strength and good adhesion after curing. However, existing chemical grouting materials have significant drawbacks in high-osmotic-pressure dynamic water environments: First, most chemical grouts are hydrophobic systems, easily diluted, emulsified, or washed away by water, exhibiting poor anti-dispersion properties, with a retention rate often below 50% under dynamic water scouring; second, they have high curing shrinkage rates (especially polyurethanes), easily forming seepage channels at the interface between the sealing material and the rock wall; third, they lack toughness, becoming brittle after curing, making it difficult to adapt to the minute deformations of the surrounding rock under high osmotic pressure, and prone to secondary cracking; fourth, some chemical grouts (such as traditional epoxy resins) have high viscosity, requiring the addition of large amounts of organic diluents, which not only affects environmental friendliness but also increases construction safety risks.

[0006] Expandable polymer materials (such as the ultra-high expansion grouting material disclosed in patent CN110835449B) achieve physical sealing by expanding upon contact with water, with an expansion ratio of over 200 times, demonstrating significant advantages in sealing wide fissures. However, these materials have three inherent drawbacks: First, their expansion performance is significantly affected by water quality. In complex environments such as acidic mine water and highly mineralized groundwater, the expansion ratio can fluctuate by more than 50%, making the sealing effect unpredictable. Second, the expansion rate is uncontrollable; the instantaneous and violent expansion upon contact with water can easily clog the grouting pipeline, leading to construction failure. Third, the curing trigger mechanism is singular, relying solely on time control or water reaction, and cannot intelligently adjust the reinforcement timing according to fissure development and stress changes, resulting in insufficient integrity and durability of the sealed body.

[0007] In summary, existing grouting materials are mostly designed with a static, single-mode structure, lacking the ability to dynamically respond to environmental parameters such as groundwater pressure, flow velocity, water quality, and temperature. This makes it difficult to achieve stable, controllable, and long-lasting sealing effects in complex and variable high-permeability environments. Overcoming the performance bottlenecks of existing materials and developing an intelligent grouting material that can actively adapt to environmental changes and achieve multi-scale collaborative sealing has become a pressing technical challenge in this field. Summary of the Invention

[0008] The purpose of this invention is to provide a grouting material for blocking fluids with strong permeability pressure. It uses modified resin microspheres with a three-layer structure as the core component and achieves multi-scale sealing of cracks through the functional division and synergy of different layers.

[0009] The technical problem solved by this invention is achieved by the following technical solution.

[0010] On one hand, embodiments of the present invention provide a grouting material for blocking fluids under strong permeability pressure; by weight, it comprises the following raw materials:

[0011] Component A: 20-40 parts; Component B: 30-50 parts; Component C: 20-40 parts;

[0012] Component A is a modified resin microsphere;

[0013] Component B, by weight, comprises 50-70 parts epoxy resin, 10-20 parts reactive diluent, and 5-10 parts anti-dispersant;

[0014] The C component, by weight, includes 40-60 parts of amine curing agent, 2-5 parts of accelerator, and 10-20 parts of toughening agent.

[0015] In some embodiments of the present invention, the modified resin microspheres include a core material, an intermediate layer, and an outer shell layer;

[0016] The core material is prepared from the following raw materials: acrylic acid, acrylamide, N,N'-methylenebisacrylamide, potassium persulfate, liquid paraffin and sorbitan oleate;

[0017] The intermediate layer is prepared from the following raw materials: acrylic acid, dimethylaminoethyl methacrylate, N,N'-methylenebisacrylamide, ammonium persulfate, aqueous ethanol solution and sodium dodecyl sulfate;

[0018] The outer shell is made from the following raw materials: dibutyltin dilaurate, triethylenediamine, polyvinyl alcohol, nano-silica, ethanol, isophorone diamine, toluene diisocyanate, and diethylenetriamine.

[0019] In some embodiments of the present invention, the modified resin microspheres are prepared by the following steps:

[0020] (1) Add sodium hydroxide solution to acrylic acid, then add acrylamide and N,N'-methylenebisacrylamide, stir to dissolve, and obtain an aqueous solution; mix liquid paraffin and sorbitan oleate to obtain an oil solution; under nitrogen protection, drop the aqueous solution into the oil solution, disperse for 30 min, add potassium persulfate, and react at 60-65℃ for 3-4 h; after the reaction is completed, cool to room temperature, filter, wash until neutral, and vacuum dry to obtain core layer microspheres;

[0021] (2) Disperse the core layer microspheres in an ethanol aqueous solution containing sodium dodecyl sulfate, stir at room temperature for 30 min, then add a well mixed mixture of acrylic acid, dimethylaminoethyl methacrylate and N,N'-methylenebisacrylamide, and stir for 2 h; raise the temperature to 50-60℃, purge with nitrogen for 30 min, add ammonium persulfate, and react for 3-4 h; after the reaction is complete, filter, wash, and vacuum dry to obtain microspheres with an intermediate layer;

[0022] (3) Add ethanol, dibutyltin dilaurate, triethylenediamine and nano silica to the polyvinyl alcohol solution, and disperse by ultrasonication to obtain a catalyst solution; react isophorone diamine with ketone compounds to prepare ketiminated isophorone diamine; use a coaxial microfluidic chip, with ketiminated isophorone diamine as the inner phase, toluene diisocyanate dissolved in an organic solvent as the intermediate phase, and an aqueous solution containing emulsifier as the outer phase, the three fluids form a coaxial jet at the microchannel outlet, shearing to form droplets; wash and dry to obtain microcapsules; place the microspheres with the intermediate layer in a fluidized bed, spray the catalyst solution into the fluidized bed, and continue fluidized drying after spraying; transport the dry powder of the microcapsules to the fluidized bed, mix with the microspheres, spray with a dilute solution of glutaraldehyde, and dry to obtain modified resin microspheres.

[0023] By employing a microfluidic chip to precisely control the size of aqueous droplets and combining it with ultrasound-assisted polymerization, the particle size distribution (CV) of the core layer microspheres is reduced to <5% (compared to >20% for conventional methods), with particle sizes concentrated within the target range of 80-120 μm. The monodisperse microspheres pack more densely and are arranged more orderly within the cracks, significantly reducing the porosity and permeability of the sealing layer. Simultaneously, the ultrasonic field enhances mass and heat transfer, ensuring uniform polymerization and avoiding uneven molecular weight distribution caused by localized overheating.

[0024] In some embodiments of the present invention, in step (1), by weight, it includes,

[0025] Acrylic acid 60-80 parts, acrylamide 20-40 parts, N,N'-methylenebisacrylamide 0.3-0.8 parts, potassium persulfate 0.2-0.5 parts, liquid paraffin 200-300 parts, sorbitan anhydride oleate 5-10 parts.

[0026] In some embodiments of the present invention, in step (2), based on the number of parts by weight of 100 parts of core layer microspheres, the product includes:

[0027] 10-20 parts acrylic acid, 10-20 parts dimethylaminoethyl methacrylate, 0.1-0.3 parts N,N'-methylenebisacrylamide, 0.1-0.2 parts ammonium persulfate, 200-220 parts aqueous ethanol solution, and 0.1-0.5 parts sodium dodecyl sulfate.

[0028] In some embodiments of the present invention, in step (3), the ratio of the amount of microspheres with intermediate layer, catalyst solution and microcapsules is 100g: (50-100)mL: (10-20)g.

[0029] In some embodiments of the present invention, the epoxy resin is a bisphenol F type epoxy resin or an alicyclic epoxy resin.

[0030] The active diluent is benzyl glycidyl ether or 1,4-butanediol diglycidyl ether.

[0031] The anti-dispersant is copolymerized from acrylamide, a hydrophobic monomer (such as hexadecylallyldimethylammonium chloride), and 2-acrylamido-2-methylpropanesulfonic acid.

[0032] Component B uses bisphenol F type epoxy resin or alicyclic epoxy resin as the main body, combined with benzyl glycidyl ether or 1,4-butanediol diglycidyl ether as an active diluent. The viscosity at 25℃ is controlled below 50 mPa·s, and the injection penetration coefficient K ≥ 10⁻ 5The material exhibits micro-cracks at a flow rate of cm / s. Simultaneously, the reactive diluent participates in the curing reaction, avoiding the volatilization losses and environmental pollution problems associated with traditional solvent-based diluents. The anti-dispersant is copolymerized from acrylamide, hydrophobic monomers, and 2-acrylamido-2-methylpropanesulfonic acid. Upon contact with water, the hydrophobic groups on its molecular chain rapidly form a dense hydrophobic film at the slurry-water interface, effectively resisting erosion by flowing water. The sulfonic acid groups promote the compatibility between the epoxy resin and the curing agent. Experiments show that at a flow rate of 1.5 m / s, the retention rate of the material of this invention is >85%, significantly superior to existing cement-based materials (80% retention rate at 0.6 m / s) and ordinary chemical slurries (<50%).

[0033] In some embodiments of the present invention, the amine curing agent is a polyether amine or a modified fatty amine; the accelerator is salicylic acid or dimethylaminomethylphenol; and the toughening agent is an amino-terminated liquid nitrile rubber or polypropylene glycol diglycidyl ether.

[0034] Component C uses water-soluble polyetheramine or modified fatty amine as a curing agent, combined with salicylic acid or dimethylaminomethylphenol as an accelerator, and amino-terminated liquid nitrile rubber or polypropylene glycol diglycidyl ether as a toughening agent, forming a fully water-based curing system. The entire formula does not contain organic solvents such as acetone or toluene, and there are no VOC emissions during the construction process, meeting green environmental protection requirements.

[0035] In some embodiments of the present invention, component B is prepared by the following steps: stirring epoxy resin, reactive diluent and anti-dispersant at 40-50°C for 1-2 hours to obtain component B;

[0036] The C component is prepared by the following steps: stirring an amine curing agent, an accelerator, a toughening agent and water at room temperature for 0.5-1 h to obtain the C component.

[0037] On the other hand, embodiments of the present invention provide a method for preparing a grouting material for blocking highly osmotic pressure fluids, comprising the following steps: mixing component A, component B and component C, stirring evenly, to obtain the grouting material.

[0038] Compared with the prior art, the embodiments of the present invention have at least the following advantages or beneficial effects:

[0039] The grouting material provided by this invention uses modified resin microspheres with a three-layer structure as its core component. Through the functional division and synergy of different layers, it achieves multi-scale sealing of cracks.

[0040] The core layer is made of ultra-high expansion rate resin, which expands rapidly upon contact with water, physically filling and squeezing out large cracks (width > 1 mm) to achieve rapid flow interception; the middle layer is a pH / ionic strength dual-sensitive hydrogel, which can dynamically adjust the rate at which water enters the core material according to the environmental water quality, avoiding premature or slow expansion of the core material and ensuring adaptability under different geological conditions; the outer shell layer is embedded with catalysts and microcapsules, which trigger the release of curing agent from the microcapsules when the microspheres expand to a certain stress threshold, forming a secondary chemical reinforcement network in synergy with components B and C.

[0041] This grouting material possesses advantages such as high expansion, high permeability, anti-dispersion, environmental adaptability, and construction friendliness. It can actively adapt to complex and variable high-permeability hydrodynamic environments, achieving multi-scale synergistic sealing of both wide and micro-fractures. It exhibits excellent sealing effects and long-term durability under extreme conditions such as karst water inrush and high-pressure water inrush in fault fracture zones, demonstrating significant technological advancements and broad engineering application prospects. Detailed Implementation

[0042] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.

[0043] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other. The present invention will now be described in detail with reference to specific embodiments.

[0044] Example 1

[0045] 1. Preparation of modified resin microspheres of component A

[0046] (1) Core layer

[0047] Raw material composition (based on the preparation of 100g core layer microspheres):

[0048] Acrylic acid: 70g (neutralization degree 60-80%, adjusted with sodium hydroxide solution),

[0049] Acrylamide: 30g

[0050] Crosslinking agent: N,N'-methylenebisacrylamide, 0.5g (0.3-0.8% of the total monomer mass).

[0051] Initiator: Potassium persulfate, 0.3g (0.2-0.5% of the total monomer mass).

[0052] Oil phase: liquid paraffin, 250 mL

[0053] Dispersant stabilizer: Span 80 (sorbitan oleate), 8g.

[0054] Preparation steps:

[0055] Aqueous phase preparation: Dilute 70g of acrylic acid with deionized water to a mass fraction of 35%. Slowly add a 30% sodium hydroxide solution under ice-water bath cooling to adjust the neutralization degree to 70±5%. Add acrylamide and N,N'-methylenebisacrylamide, stir to dissolve, and obtain an aqueous monomer solution.

[0056] Oil phase preparation: Add liquid paraffin and Span 80 to a three-necked flask equipped with a stirrer, thermometer and nitrogen inlet, heat to 60°C and purge with nitrogen for 30 min to remove oxygen.

[0057] Suspension polymerization: Under nitrogen protection, the aqueous monomer solution was slowly added dropwise to the oil phase, and the stirring speed was adjusted to control the droplet size at 100 μm (which can be observed through a sampling microscope). After stable dispersion for 30 min, potassium persulfate (pre-dissolved in a small amount of water) was added as the initiator, and the reaction was continued at 60 °C for 3.5 h.

[0058] Post-processing: After the reaction is complete, cool to room temperature, filter, wash three times with acetone or ethanol to remove the oil phase, wash with deionized water until neutral, and dry under vacuum at 50-60℃ to constant weight to obtain core layer microspheres.

[0059] (2) Intermediate layer

[0060] Raw material composition (based on 100g of core layer microspheres):

[0061] Acrylic acid: 15g

[0062] Dimethylaminoethyl methacrylate (DMAEMA): 15g

[0063] Crosslinking agent: N,N'-methylenebisacrylamide, 0.2g,

[0064] Initiator: Ammonium persulfate, 0.15g

[0065] Solvent: ethanol / water mixture (1:1 by volume), 200 mL

[0066] Surfactant: Sodium dodecyl sulfate (SDS), 0.3g.

[0067] Preparation steps:

[0068] The core layer microspheres were dispersed in an ethanol / water mixture containing SDS and stirred at room temperature for 30 min to allow the surface of the microspheres to swell and adsorb some monomers, thus obtaining the dispersion system.

[0069] Acrylic acid, DMAEMA, and N,N'-methylenebisacrylamide were mixed evenly and added to the above dispersion system. Stirring was continued for 2 hours to allow the monomers and crosslinking agents to fully penetrate into the surface of the microspheres.

[0070] Heat to 50-60℃, purge with nitrogen for 30 min, add ammonium persulfate (dissolved in a small amount of water) as initiator, and react for 4 h. During this period, add an appropriate amount of ethanol / water to maintain dispersion.

[0071] After the reaction was completed, the mixture was filtered, washed three times with ethanol to remove unreacted monomers, washed with deionized water, and dried under vacuum at 40°C to obtain microspheres with an intermediate layer.

[0072] (3) Outer shell layer

[0073] Preparation of catalyst solution

[0074] Organotin catalyst: Dibutyltin dilaurate, 8 g

[0075] Tertiary amine catalyst: Triethylenediamine, 4g

[0076] Film-forming agent: Polyvinyl alcohol (PVA, type 1788), 3 g,

[0077] Nano silica: particle size 20-50 nm, 8g (used to increase surface roughness and embedding firmness).

[0078] Solvent: Ethanol, 100 mL.

[0079] PVA was dissolved in 80℃ hot water to prepare a 5% solution. After cooling, ethanol was added for dilution. Then, dibutyltin dilaurate, triethylenediamine, and nano-silica were added in sequence and ultrasonically dispersed for 30 min to obtain the catalyst solution.

[0080] Add 100g of IPDA to a dry three-necked flask, add 180g of methyl isobutyl ketone (MIBK), and stir until homogeneous. Heat to 110-120℃ and reflux for 5 hours, followed by azeotropic dehydration until the amount of water separated reaches the theoretical value (approximately 18-22g). Remove excess MIBK and the water generated in the reaction by vacuum distillation (vacuum degree -0.09MPa, temperature 80-90℃) to obtain a light yellow transparent liquid ketiminated IPDA.

[0081] Microcapsules prepared by microfluidic interfacial polymerization

[0082] Chip material: glass;

[0083] Channel dimensions: inner phase channel 150μm, intermediate phase channel 250μm, outer phase channel 400μm; outlet nozzle diameter: 300μm;

[0084] Internal phase: Ketoiminated IPDA 100g (use directly, viscosity approximately 50-100 mPa·s; if viscosity is too low, add 1-3% ethyl cellulose to thicken).

[0085] Mesophase: 60g TDI + 120g cyclohexane + 0.8g DBTDL, mixed thoroughly;

[0086] External phase: 600g deionized water + 4g PVA-1788 + 0.2g SDS, stir to dissolve;

[0087] The three fluids were injected into the microfluidic chip through a precision injection pump, with the inner phase flow rate being 3 mL / h, the intermediate phase flow rate being 6 mL / h, and the outer phase flow rate being 30 mL / h.

[0088] The droplets fall into a collecting bath (external phase with the same formulation, temperature 25-30℃), where TDI polymerizes with the internal phase at the interface to form a polyurea capsule wall. The reaction is continued with stirring for 3 hours to allow the capsule wall to fully solidify. The mixture is then filtered or centrifuged, and washed three times sequentially with deionized water and ethanol to remove unreacted substances and solvent. Finally, it is dried under low-temperature vacuum (30-40℃, -0.08MPa, 4-6 hours) to obtain microcapsules.

[0089] (4) Composite coating of outer shell layer

[0090] Microspheres with an encapsulated middle layer: 100 g

[0091] Catalyst solution: 80 mL

[0092] Microcapsules: 15g

[0093] Dilute glutaraldehyde solution (0.5wt%): 10mL.

[0094] The microspheres coated with the intermediate layer were placed in a fluidized bed at a fluidized air temperature of 45°C. The catalyst embedding solution was uniformly sprayed into the fluidized bed using a spray device, wetting the surface of the microspheres and adhering the catalyst and nano-silica. After spraying, fluidized drying continued for 30 min. The microcapsule powder was then mixed with the microspheres via an airflow, utilizing the residual viscosity of the microsphere surface (or by additionally spraying a small amount of adhesive such as PVA solution) to adhere the microcapsules to the microsphere surface. A small amount of crosslinking agent (dilute glutaraldehyde solution) was sprayed again to slightly crosslink and fix the surface catalyst layer, and then dried at 50°C for 1 h to obtain the final component A microspheres.

[0095] 2. Preparation of component B

[0096] 60g of bisphenol F type epoxy resin, 15g of benzyl glycidyl ether, and 8g of anti-dispersant were stirred at 40-50℃ for 1-2 hours to obtain component B. The anti-dispersant was a copolymer of acrylamide, AMPS, and hexadecyl allyl dimethyl ammonium chloride with a molecular weight of 800,000.

[0097] 3. Preparation of component C

[0098] Component C is obtained by stirring 45g of polyetheramine D230, 3g of salicylic acid, 15g of amino-terminated liquid nitrile rubber, and 37g of water at room temperature for 0.5-1h.

[0099] 4. Preparation of grouting materials

[0100] Mix 30g of component A, 40g of component B, and 30g of component C, and stir until homogeneous to obtain the grouting material.

[0101] Example 2

[0102] The difference from the example is that the amounts of each raw material are as follows:

[0103] Component A:

[0104] Core layer: 60g acrylic acid, 20g acrylamide, 0.3g MBA, 0.2g potassium persulfate, 200mL liquid paraffin, 5g Span80.

[0105] Intermediate layer: Acrylic acid 10g, DMAEMA 10g, MBA 0.1g, ammonium persulfate 0.1g, ethanol / water 200mL, SDS 0.1g.

[0106] Outer shell: 50 mL catalyst solution (DBTDL 5 g, TEDA 2 g, PVA 2 g, nano-SiO2 5 g, ethanol 80 mL), 10 g microcapsules.

[0107] Component B: 50g epoxy resin, 10g reactive diluent, 5g anti-dispersant (total 65g).

[0108] Component C: 40g polyetheramine, 2g salicylic acid, 10g toughening agent, 30g water (total 82g).

[0109] Grouting material ratio: Component A 20g, Component B 30g, Component C 20g.

[0110] The preparation method is the same as in Example 1.

[0111] Example 3

[0112] The difference from Example 1 is that the amounts of each raw material are as follows:

[0113] Preparation of component A

[0114] Core layer: 80g acrylic acid, 40g acrylamide, 0.8g MBA, 0.5g potassium persulfate, 300mL liquid paraffin, 10g Span80;

[0115] Intermediate layer: 20g acrylic acid, 20g DMAEMA, 0.3g MBA, 0.2g ammonium persulfate, 220mL ethanol / water, 0.5g SDS;

[0116] Outer shell: 100mL catalyst solution (DBTDL 10g, TEDA 5g, PVA 5g, nano SiO2 10g, ethanol 120mL), 20g microcapsules;

[0117] Component B: 70g epoxy resin, 20g reactive diluent, 10g anti-dispersant (total 100g).

[0118] Component C: 60g polyetheramine, 5g salicylic acid, 20g toughening agent, 45g water (total 130g).

[0119] Grouting material ratio: 40g of component A, 50g of component B, and 40g of component C.

[0120] The preparation method is the same as in Example 1.

[0121] Example 4

[0122] The difference from Example 1 is that the amounts of each raw material are as follows:

[0123] Component A, core layer: 65g acrylic acid, 25g acrylamide, 0.4g MBA, 0.3g potassium persulfate, 220mL liquid paraffin, 6g Span80;

[0124] Intermediate layer: 12g acrylic acid, 12g DMAEMA, 0.15g MBA, 0.12g ammonium persulfate, 200mL ethanol / water, 0.2g SDS;

[0125] Outer shell: 60 mL catalyst solution, 12 g microcapsules;

[0126] Component B: 55g epoxy resin, 12g reactive diluent, 6g anti-dispersant (total 73g).

[0127] Component C: 45g polyetheramine, 3g salicylic acid, 12g toughening agent, 32g water (total 92g).

[0128] Grouting material ratio: Component A 25g, Component B 35g, Component C 25g.

[0129] The preparation method is the same as in Example 1.

[0130] Example 5

[0131] The difference from Example 1 is that the amounts of each raw material are as follows:

[0132] Component A, core layer: acrylic acid 75g, acrylamide 35g, MBA 0.6g, potassium persulfate 0.4g, liquid paraffin 280mL, Span80 9g;

[0133] Intermediate layer: 18g acrylic acid, 18g DMAEMA, 0.25g MBA, 0.18g ammonium persulfate, 210mL ethanol / water, 0.4g SDS;

[0134] Outer shell: 80 mL catalyst solution, 18 g microcapsules;

[0135] Component B: 65g epoxy resin, 18g reactive diluent, 9g anti-dispersant (total 92g)

[0136] Component C: 55g polyetheramine, 4g salicylic acid, 18g toughening agent, 40g water (total 117g)

[0137] Grouting material mix ratio: 35g of component A, 45g of component B, and 35g of component C.

[0138] The preparation method is the same as in Example 1.

[0139] Example 6

[0140] The difference from Example 1 is that the amounts of each raw material are as follows:

[0141] Core layer: 72g acrylic acid, 32g acrylamide, 0.5g MBA, 0.4g potassium persulfate, 260mL liquid paraffin, 8g Span80;

[0142] Intermediate layer: 16g acrylic acid, 16g DMAEMA, 0.2g MBA, 0.15g ammonium persulfate, 200mL ethanol / water, 0.3g SDS;

[0143] Outer shell: 75 mL catalyst solution, 15 g microcapsules;

[0144] Component B: 62g alicyclic epoxy resin, 16g 1,4-butanediol diglycidyl ether, 8g anti-dispersant (total 86g).

[0145] Component C: 50g modified fatty amine, 3.5g dimethylaminomethylphenol, 16g polypropylene glycol diglycidyl ether, 35g water (total 104.5g).

[0146] Grouting material mix ratio: Component A 30g, Component B 42g, Component C 28g.

[0147] Comparative Example 1

[0148] The difference from Example 1 is that, in preparing the modified resin microspheres of component A, the intermediate layer coating step is omitted, and the core layer microspheres are directly assembled into the outer shell layer. The remaining raw material amounts and preparation methods are the same as in Example 1.

[0149] Comparative Example 2

[0150] The difference from Example 1 is that, in preparing the modified resin microspheres of component A, no microcapsules were added to the outer shell layer; only the catalyst was embedded. The remaining raw material amounts and preparation methods are the same as in Example 1.

[0151] Comparative Example 3

[0152] The difference from Example 1 is that no anti-dispersant is added to component B. The remaining raw material amounts and preparation methods are the same as in Example 1.

[0153] Comparative Example 4

[0154] The difference from Example 1 is that conventional suspension polymerization (mechanical stirring) was used to prepare the modified resin microspheres of component A, without microfluidic control. The remaining raw material amounts and preparation methods are the same as in Example 1.

[0155] Experimental Example

[0156] 1. Numerical Performance Testing of Component A Microspheres

[0157] (1) Expansion ratio test: Weigh the mass of the dried microspheres, soak them in excess liquid until they are fully expanded, filter out the excess liquid, weigh them, and calculate the mass expansion ratio.

[0158] Test Procedure: Take approximately 0.5g of dried microspheres (accurate to 0.001g), denoted as m0, and place them in a 400-mesh nylon mesh bag, then seal it. Immerse the mesh bag in sufficient test liquid (pure water, pH=3 hydrochloric acid solution, pH=11 sodium hydroxide solution, or 50,000 ppm NaCl solution) at a temperature of 25±1℃. Soak for 24 hours (preliminary experiments show that the microspheres of this invention reach equilibrium within 2 hours; for safety, 24 hours is used). Remove the mesh bag and gently blot off excess liquid from the surface with filter paper. Weigh the total mass of the microspheres and mesh bag after water absorption, denoted as m1. The mass of the mesh bag after unloaded wetting is denoted as m_w.

[0159] The expansion ratio was calculated using the formula: Sw = (m1 - m_w - m0) / m0. Three parallel samples were tested in each group, and the average value was taken. The results are shown in Table 1.

[0160] (2) Microsphere size distribution test

[0161] The test was conducted using a laser particle size analyzer (Malvern Mastersizer 3000).

[0162] Test Procedure: Take approximately 0.5 g of dried microspheres and add them to the dispersion medium (anhydrous ethanol). Disperse ultrasonically for 30 seconds. Set the instrument parameters: refractive index 1.53, absorptivity 0.01, measurement range 0.1-1000 μm. Perform cyclic injection, and begin measurement when the occlusion stabilizes at 10-15%. Record the D10, D50, and D90 values, and calculate the particle size distribution CV: CV = (D90 - D10) / (2 × D50) × 100%.

[0163] (3) Grouting material slurry performance test

[0164] A. Viscosity test

[0165] The rotational viscometer method was adopted, referring to GB / T 2794-2013.

[0166] Test Procedure: Immediately inject the freshly prepared slurry (example and comparative examples) into the test container. Use a Brookfield DV2T viscometer with a suitable rotor (rotor #62) at 25±0.5℃ and a rotation speed of 60 rpm. After the reading stabilizes (approximately 30 seconds), record the viscosity value. Perform three tests per group and take the average value.

[0167] B. Initial setting time test

[0168] The Vicat method was adopted, referring to GB / T 1346-2011.

[0169] Test Procedure: Pour 100 mL of slurry into a cylindrical mold (φ50 mm × 50 mm). Place the mold in a water bath at 25 ± 1 °C (simulating underwater setting) or in air (simulating above-water setting). Test every 1 minute using a Vicat probe (1.1 mm diameter, 300 g) until the probe penetrates no more than 1 mm into the mold. Record this time as the initial setting time. Perform three parallel tests per group and take the average value.

[0170] C. Expansion Time Test

[0171] Take 50 mL of the slurry and slowly pour it into a transparent container containing 200 mL of water at 25°C. Immediately start timing and record the data continuously. Observe the change in slurry volume and record the time when the volume begins to increase significantly (T_start) and the time when the volume stops changing (T_end). Expansion time = T_end - T_start.

[0172] D. Flow retention rate test

[0173] The simulated water flushing system consists of a water pump, flow meter, valves, test pipe section (φ50mm×500mm transparent plexiglass tube with a built-in replaceable standard sand filling section), and screen collector.

[0174] Test Procedure: Fill the test pipe section with standard sand (particle size 1-2mm, simulating fractured media), and fix both ends with a 100-mesh sieve. Adjust the water flow rate to the set value (0.5, 1.0, 1.5m / s) and stabilize for 5 minutes. Take 100g of slurry and inject it uniformly into the upstream of the test pipe section through the grouting port within 30 seconds. Continuously flush for 10 minutes, collecting the slurry solidification intercepted by the downstream sieve, as well as the slurry solidification remaining in the test pipe section. Dry the collected material at 60℃ to constant weight, and record the weight as m_retained. Take another 100g of slurry and dry it directly to constant weight, and record the weight as m_total. Dynamic water retention rate = m_retained / m_total × 100%. Each group is tested 3 times, and the average value is taken.

[0175] E. Compressive strength test

[0176] Refer to GB / T 17671-2021 "Test Method for Strength of Cement Mortar".

[0177] Sample preparation: The slurry was poured into a 40mm×40mm×40mm triple mold. After curing under standard curing conditions (20±2℃, RH≥95%) for 24 hours, the sample was demolded. Curing continued until the specified age (3d, 7d, 14d, 28d).

[0178] Test Procedure: Use a universal testing machine (e.g., Instron 5982) with a loading rate of 2.4 kN / s. Place the specimen in the center of the pressure plate and start the testing machine until failure. Record the maximum load F (N) and calculate the compressive strength using the formula: Rc = F / (40×40) = F / 1600 (MPa). Test 3 specimens per group and take the average value.

[0179] F. Rock bond strength test

[0180] Test method: Refer to the splitting tensile test method in DL / T 5150-2017 "Test Procedure for Hydraulic Concrete".

[0181] Specimen preparation (split tensile test): Prepare cylindrical rock specimens (granite) with a diameter of φ50mm × 50mm, and split them into two halves along the axial direction. Apply grout to the split surface, re-bond the two halves of the specimen, and fix them with clamps. Standard curing for 28 days.

[0182] Test Procedure: Place the bonded specimen in the splitting fixture, ensuring the bond joint is parallel to the loading direction. Load at a rate of 0.5 mm / min until the specimen splits and fails. Record the maximum load P (N) and calculate the bond strength using the formula: σ = 2P / (π × 50 × 50) = P / 3927 (MPa). Test 5 specimens per group and take the average value.

[0183] G. Elongation at break test

[0184] Refer to GB / T 528-2009 "Determination of tensile stress-strain properties of vulcanized rubber or thermoplastic rubber".

[0185] Sample preparation: Pour the slurry into a dumbbell-shaped mold (total length 75mm, narrow section width 4mm, thickness 2mm). Standard curing for 28 days.

[0186] Test procedure: A universal testing machine was used with a clamp spacing of 25 mm and a tensile rate of 50 mm / min. The elongation at fracture ΔL was recorded, and the elongation at fracture was calculated as: ε = ΔL / 25 × 100%. Five specimens were tested in each group, and the average value was taken.

[0187] H. Blocking performance test

[0188] Refer to the variable head permeability test in GB / T 50123-2019 "Standard for Geotechnical Testing Methods".

[0189] Specimens: Artificial fracture specimens were prepared using the rock drilling and splitting method. A standard 100mm × 100mm × 100mm rock block (granite or sandstone) was split along its center. A release agent was evenly applied to both sides of the split surface. The two halves of the block were then reassembled and fixed with clamps, controlling the fracture width to 2mm. Grouting material was injected into the fracture through the grouting hole at a pressure of 0.5MPa for 5 minutes. After grouting, the specimens were cured under standard curing conditions for 28 days for permeability and bond strength testing.

[0190] Test Procedure: Place the specimen into the permeameter and seal the sidewalls. Apply a water pressure of 0.5 MPa and stabilize for 30 minutes. Record the water flow rate Q (cm³ / s), specimen cross-sectional area A (cm²), and hydraulic gradient i per unit time. Calculate the permeability coefficient using Darcy's Law: K = Q / (A × i) (cm / s). Test three specimens per group and take the average value.

[0191] I. Microcapsule Performance Testing

[0192] The single-particle compression method was used to measure the force when the microcapsules ruptured using a nanoindenter, and the force was converted into stress.

[0193] Test Procedure: Microcapsules were dispersed on a glass slide, and individual microcapsules were positioned under a microscope. A nanoindenter (Hysitron TI 950) equipped with a flat-head indenter (50 μm in diameter) was used. The microcapsules were compressed at a rate of 0.1 μm / s, and the force-displacement curve was recorded. The force corresponding to the first significant drop point on the curve is the fracture force F_b (μN). The microcapsule diameter d (μm) was measured using a microscope, and the fracture stress was calculated as: σ_b = F_b / (π×(d / 2)²) (MPa). Twenty microcapsules were randomly measured, and the average value was taken as the stress response threshold.

[0194] Table 1

[0195]

[0196] Table 2

[0197]

[0198] From Tables 1 and 2, it can be concluded that Example 1 has the best overall performance, Example 3 has the highest expansion ratio and strength but slightly reduced toughness, Example 2 has the lowest cost but slightly sacrifices performance, and the intermediate combination of Examples 4-6 has stable performance.

[0199] Comparative Example 1 showed a slightly higher expansion ratio in pure water than the Example, but its expansion performance decreased significantly in acidic, alkaline, and saline environments (retention rate was only 55-62%), demonstrating the crucial role of the intermediate layer in water quality adaptability.

[0200] Comparative Example 2 showed a shortened initial setting time and acceptable early strength, but significantly deteriorated long-term durability: after 30 days of dynamic water flushing, the permeability increased by 3 orders of magnitude and the mass loss rate reached as high as 8.5%, demonstrating the importance of stress-responsive microcapsules for secondary reinforcement and long-term stability.

[0201] Comparative Example 3 showed a catastrophic decline in performance in a dynamic water environment, with a retention rate of only 28% at a flow rate of 1.5 m / s and no normal solidification at flow rates above 1.0 m / s, demonstrating the necessity of anti-dispersants in dynamic water environments.

[0202] The resin microspheres of component A in the grouting material provided in the above embodiments have an intermediate layer made of a dual-sensitive hydrogel formed by copolymerization of acrylic acid and dimethylaminoethyl methacrylate. Its swelling behavior can be dynamically adjusted according to changes in environmental pH and ionic strength. When encountering acidic mine water (pH=2-4), alkaline limestone water (pH=8-10), or highly mineralized groundwater (total mineralization >50000ppm), the intermediate layer intelligently regulates the rate at which water molecules enter the core material through changes in molecular chain conformation, keeping the core material's expansion rate relatively stable under different water quality conditions. Experiments show that the expansion ratio fluctuation of the material of this invention in water with pH=3 and pH=11 is <10%, while that of conventional expansion materials is >50%, significantly improving the material's adaptability to complex water qualities.

[0203] The stress-responsive microcapsules attached to the outer shell contain a delayed-curing agent. The capsule walls rupture and release their contents only when subjected to a certain stress threshold (0.3-1.0 MPa) under pressure from the surrounding rock mass or the expanded core material. This allows secondary reinforcement and fracture development to occur simultaneously: when the stress generated by the core material expansion reaches the threshold, the microcapsules rupture, releasing the curing agent, which reacts with the epoxy resin in component B to form a high-strength three-dimensional network penetrating the microspheres and the rock wall. This differs from existing technologies that rely solely on time-controlled curing mechanisms.

[0204] In this embodiment of the invention, components A, B, and C are compounded in a specific ratio, resulting in complementary functions and synergistic effects among the three components:

[0205] Component A acts as a framework and trigger, filling the crack space through volume expansion and releasing the catalyst to trigger subsequent reactions;

[0206] Component B, acting as both a carrier liquid and a penetrant, possesses low viscosity (≤50 mPa·s), ensuring the smooth delivery of the microspheres from component A. Simultaneously, it can penetrate deep into micro-cracks (<0.1 mm) to form the first layer of chemical reinforcement.

[0207] Component C, acting as a delayed reinforcement agent, is released upon triggering by component A and reacts with component B to form a second reinforcement network. The synergistic effect of the three components produces a cumulative effect: component A alone can only physically seal the surface, but its strength is insufficient; components B and C alone can chemically solidify the surface, but they are difficult to resist the erosion of flowing water; when the three components are combined, physical expansion and chemical cross-linking complement each other, significantly improving both sealing efficiency and durability.

[0208] The embodiments described above are some, but not all, embodiments of the present invention. The detailed description of the embodiments of the present invention is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

Claims

1. A grouting material for blocking fluids with high osmotic pressure, characterized in that, By weight, it includes the following ingredients: Component A: 20-40 parts; Component B: 30-50 parts; Component C: 20-40 parts; Component A is a modified resin microsphere; Component B, by weight, comprises 50-70 parts epoxy resin, 10-20 parts reactive diluent, and 5-10 parts anti-dispersant; The C component, by weight, includes 40-60 parts of amine curing agent, 2-5 parts of accelerator, and 10-20 parts of toughening agent.

2. The grouting material for blocking high-permeability fluids according to claim 1, characterized in that, The modified resin microspheres include a core material, an intermediate layer, and an outer shell layer; The core material is prepared from the following raw materials: acrylic acid, acrylamide, N,N'-methylenebisacrylamide, potassium persulfate, liquid paraffin and sorbitan oleate; The intermediate layer is prepared from the following raw materials: acrylic acid, dimethylaminoethyl methacrylate, N,N'-methylenebisacrylamide, ammonium persulfate, aqueous ethanol solution and sodium dodecyl sulfate; The outer shell is made from the following raw materials: dibutyltin dilaurate, triethylenediamine, polyvinyl alcohol, nano-silica, ethanol, isophorone diamine, toluene diisocyanate, and diethylenetriamine.

3. The grouting material for blocking high-permeability pressure fluids according to claim 2, characterized in that, The modified resin microspheres are prepared by the following steps: (1) Add sodium hydroxide solution to acrylic acid, then add acrylamide and N,N'-methylenebisacrylamide, stir to dissolve, and obtain an aqueous solution; mix liquid paraffin and sorbitan oleate to obtain an oil solution; Under nitrogen protection, the aqueous phase solution was dropped into the oil phase solution and dispersed for 30 min. Then, potassium persulfate was added and the reaction was carried out at 60-65℃ for 3-4 h. After the reaction was completed, the solution was cooled to room temperature, filtered, washed until neutral, and vacuum dried to obtain core layer microspheres. (2) Disperse the core layer microspheres in an ethanol aqueous solution containing sodium dodecyl sulfate, stir at room temperature for 30 min, then add a well mixed mixture of acrylic acid, dimethylaminoethyl methacrylate and N,N'-methylenebisacrylamide, and stir for 2 h; raise the temperature to 50-60℃, purge with nitrogen for 30 min, add ammonium persulfate, and react for 3-4 h; after the reaction is complete, filter, wash, and vacuum dry to obtain microspheres with an intermediate layer; (3) Add ethanol, dibutyltin dilaurate, triethylenediamine and nano silica to the polyvinyl alcohol solution, and disperse by ultrasonication to obtain a catalyst solution; react isophorone diamine with ketone compounds to prepare ketiminated isophorone diamine; use a coaxial microfluidic chip, with ketiminated isophorone diamine as the inner phase, toluene diisocyanate dissolved in an organic solvent as the intermediate phase, and an aqueous solution containing emulsifier as the outer phase, the three fluids form a coaxial jet at the microchannel outlet, shearing to form droplets; wash and dry to obtain microcapsules; place the microspheres with the intermediate layer in a fluidized bed, spray the catalyst solution into the fluidized bed, and continue fluidized drying after spraying; transport the dry powder of the microcapsules to the fluidized bed, mix with the microspheres, spray with a dilute solution of glutaraldehyde, and dry to obtain modified resin microspheres.

4. The grouting material for blocking high-permeability fluids according to claim 3, characterized in that, In step (1), by weight, it includes, Acrylic acid 60-80 parts, acrylamide 20-40 parts, N,N'-methylenebisacrylamide 0.3-0.8 parts, potassium persulfate 0.2-0.5 parts, liquid paraffin 200-300 parts, sorbitan anhydride oleate 5-10 parts.

5. The grouting material for blocking high-permeability fluids according to claim 3, characterized in that, In step (2), based on the number of parts by weight of 100 core layer microspheres, the product includes: 10-20 parts acrylic acid, 10-20 parts dimethylaminoethyl methacrylate, 0.1-0.3 parts N,N'-methylenebisacrylamide, 0.1-0.2 parts ammonium persulfate, 200-220 parts aqueous ethanol solution, and 0.1-0.5 parts sodium dodecyl sulfate.

6. The grouting material for blocking high-permeability fluids according to claim 3, characterized in that, In step (3), the ratio of the amount of microspheres with intermediate layer, catalyst solution and microcapsules is 100g: (50-100)mL: (10-20)g.

7. The grouting material for blocking high-permeability fluids according to claim 1, characterized in that, The epoxy resin is a bisphenol F type epoxy resin or an alicyclic epoxy resin; The active diluent is benzyl glycidyl ether or 1,4-butanediol diglycidyl ether. The anti-dispersant is copolymerized from acrylamide, a hydrophobic monomer (such as hexadecylallyldimethylammonium chloride), and 2-acrylamido-2-methylpropanesulfonic acid.

8. The grouting material for blocking high-permeability fluids according to claim 1, characterized in that, The amine curing agent is a polyether amine or a modified aliphatic amine; The accelerator is salicylic acid or dimethylaminomethylphenol; The toughening agent is an amino-terminated liquid nitrile rubber or polypropylene glycol diglycidyl ether.

9. The grouting material for blocking high-permeability fluids according to claim 1, characterized in that, Component B is prepared by the following steps: stirring epoxy resin, reactive diluent and anti-dispersant at 40-50℃ for 1-2 hours to obtain component B; The C component is prepared by the following steps: stirring an amine curing agent, an accelerator, a toughening agent and water at room temperature for 0.5-1 h to obtain the C component.

10. A method for preparing a grouting material for blocking high-permeability fluids as described in any one of claims 1-9, characterized in that, Includes the following steps: Mix components A, B, and C thoroughly to obtain the grouting material.

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