Solid-liquid dual-modified epoxy resin-based anti-collapse plugging agent and preparation method thereof

Abstract

The invention discloses a preparation method of a solid-liquid dual-modified epoxy resin-based anti-collapse plugging agent, which is characterized in that a liquid thiourea modified polyamine epoxy hardener and a solid amine modified super absorbent resin are synchronously prepared through a one-step reaction, so that the liquid thiourea modified polyamine epoxy hardener and the solid amine modified super absorbent resin are flexibly compounded for use; the specific preparation method comprises the following steps: mixing thiourea, a polyamine curing agent and super absorbent resin in proportion, carrying out condensation reflux reaction at 100-130 DEG C, and separating to obtain a liquid thiourea modified polyamine epoxy curing agent and a solid amine modified super absorbent resin; and mixing the liquid thiourea modified polyamine epoxy curing agent and the solid amine modified super absorbent resin with epoxy resin, a flexibilizer, an active diluent and an accelerant to obtain the solid-liquid double modified epoxy resin-based anti-collapse plugging agent. The preparation process is simple, the raw materials are easy to obtain, and the prepared solid-liquid dual-modified epoxy resin-based anti-collapse plugging agent has fast curing property and excellent compression resistance, and is especially suitable for underwater repair of earth and rockfill dam microcracks.

Description

Technical Field

[0001] The invention belongs to the field of earth dam leakage, and particularly relates to a solid-liquid dual-modified epoxy resin-based anti-collapse plugging agent and a preparation method thereof. Background Art

[0002] Most earth-rock dams in my country were built in the 20th century, primarily for flood control, irrigation, water supply, and power generation. Limited by the economic conditions and construction techniques of the time, these dams now experience varying degrees of leakage. Therefore, addressing these leaks has become a crucial issue for the national economy and security. However, existing research has focused on addressing macroscopic leakage pathways, with insufficient attention paid to the hidden hazards of microcracks. These cracks initially leak little and are difficult to detect using conventional monitoring methods, but they continue to expand through mechanisms such as seepage and erosion, ultimately leading to catastrophic consequences.

[0003] Epoxy resin is a polymer material containing two or more epoxy groups within its molecule. It has attracted much attention due to its advantages such as low cost, good chemical stability, and high strength. It is often used as a resin matrix for adhesives, coatings, and composite materials, and has been widely used in fields such as construction and water conservancy. However, traditional epoxy resin plugging materials have a long curing time and easily collapse in a flowing water environment, resulting in plugging failure. Therefore, accelerating the curing rate of epoxy resin-based plugging materials and being able to withstand a certain water pressure before they are fully cured is an effective method to solve the above problems. To solve the problem of the slow underwater curing speed of epoxy resin, a Chinese patent (publication number: CN 119528852A) combines the curing properties of amides and phenalkamines to prepare an epoxy resin material with a suitable curing speed, which is particularly suitable for high humidity environments and underwater environments. However, its preparation method involves a multi-step reaction and harsh process conditions. A Chinese patent (publication number: CN107216609A) proposes a rapid leak-proof epoxy resin grouting material with moderate viscosity, fast curing speed, and a large number of hydrophobic groups, allowing it to cure underwater at room temperature. Similarly, a Chinese patent (publication number: CN116769282 A) discloses a high-performance epoxy grouting material that can be used for water-stopping, leak-proofing, and reinforcement. This material relies on a reaction accelerator to rapidly increase viscosity and solidify as quickly as possible to withstand water pressure. However, simply increasing the curing reaction speed of the epoxy to prevent underwater collapse reduces its fluidity and diffusion capacity. Li et al. prepared a collapse-resistant leak-proof material by adding quartz sand, calcium carbonate, and graphite powder to the epoxy system. Among them, quartz sand is used as aggregate, calcium carbonate and graphite powder can improve the density of the material, and the hydrophobicity of graphite powder reduces water penetration (Investigation on the working performance of anon-dispersible grouting material for the crack repair of underwater structures[J].Construction and Building Materials,2023,407,133558). However, the filler particles in this material are large and are not suitable for plugging microleakage. Therefore, it is very important to develop an epoxy-based microleakage plugging agent with a simple preparation method, good plugging and water pressure resistance. Summary of the Invention

[0004] To address the problems of the existing technology, the present invention proposes a method for preparing a solid-liquid dual-modified epoxy resin-based anti-collapse plugging agent. This method simultaneously produces a liquid thiourea-modified polyamine epoxy curing agent and a solid amine-modified superabsorbent resin through a one-step reaction. This allows for easy separation of the two components, facilitating the regulation of their dosage in the epoxy resin-based plugging agent. The thiourea-modified polyamine epoxy curing agent accelerates the curing rate of the epoxy resin, while the amine-modified superabsorbent resin resists water pressure by expanding itself and covalently bonds with the epoxy resin, preventing the water-blocking material from collapsing before curing.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] A method for preparing a solid-liquid dual-modified epoxy resin-based anti-collapse plugging agent is specifically implemented according to the following steps:

[0007] Step 1: uniformly mix thiourea, a polyamine curing agent, and a super absorbent resin, and react under condensation reflux at 100 to 130° C. for 30 to 60 minutes to obtain a modified mixture;

[0008] Step 2: The modified mixture obtained in step 1 is naturally precipitated. The upper liquid is the thiourea-modified polyamine epoxy curing agent, which is recorded as component A. The precipitate is the amine-modified super absorbent resin. The two are separated by filtration, and the precipitate is washed with ethanol, dried, and ground to obtain a solid amine-modified super absorbent resin, which is recorded as component B.

[0009] Step 3: Add component A and component B obtained in step 2 to the epoxy resin system, which includes epoxy resin, toughening agent, active diluent, and accelerator, and stir the mixture evenly to obtain a solid-liquid dual-modified epoxy resin-based anti-collapse plugging agent.

[0010] Furthermore, the polyamine curing agent in step 1 is a phenalkamine curing agent, a fatty amine curing agent or an aromatic amine curing agent.

[0011] Furthermore, the super absorbent resin in step 1 is polyacrylate, and the particle size is 100-300 mesh.

[0012] Furthermore, the mass ratio of thiourea, polyamine curing agent and super absorbent resin in step 1 is 1.0:6.0-9.0:3.5-5.0.

[0013] Furthermore, the amount of ethanol used in step 2 is 1 to 3 times the mass of the precipitate, the drying temperature is 60 to 80° C., and the drying time is 10 hours.

[0014] Furthermore, the epoxy resin molecule in step 3 contains two or more epoxy groups, and the epoxy resin is any one of bisphenol A epoxy resin, novolac epoxy resin, and glycidylamine epoxy resin; the toughening agent is any one of polyurethane toughening resin and carboxyl-terminated nitrile rubber; the reactive diluent is a glycidyl ether, including any one of benzyl glycidyl ether and butanediol diglycidyl ether; the accelerator is any one of triethylbenzyl ammonium chloride and 2,4,6-tris(dimethylaminomethyl)phenol.

[0015] Furthermore, in step 3, the components A are 20 to 30 parts, component B is 15 to 55 parts, epoxy resin is 100 parts, toughening agent is 60 to 80 parts, active diluent is 10 to 20 parts, and accelerator is 3 to 7 parts.

[0016] The solid-liquid double-modified epoxy resin-based anti-collapse plugging agent prepared according to the preparation method of the above-mentioned solid-liquid double-modified epoxy resin-based anti-collapse plugging agent needs to be prepared and used immediately and within 10 minutes.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] The present invention proposes a method for preparing a solid-liquid dual-modified epoxy resin-based anti-collapse plugging agent. Through a one-step reaction, a liquid thiourea-modified polyamine epoxy curing agent (component A) and a solid amine-modified superabsorbent resin (component B) are simultaneously prepared, achieving the purpose of separate use and flexible ratio control. When the epoxy resin-based plugging material is injected into microcracks, the surface-modified superabsorbent resin swells upon contact with water to seal the leaks. It also has good pressure-bearing capacity, ensuring that the plugging material is not disintegrated by water impact before solidification. After the material solidifies, the surface-modified superabsorbent resin and the epoxy resin have strong interfacial bonding, improving the plugging effect and plugging stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a flow chart of a method for preparing a solid-liquid dual-modified epoxy resin-based anti-collapse plugging agent of the present invention;

[0020] Figure 2 This is a diagram of the laboratory self-assembled plugging agent anti-collapse performance test device. DETAILED DESCRIPTION

[0021] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0022] A method for preparing a solid-liquid dual-modified epoxy resin-based anti-collapse plugging agent is specifically implemented according to the following steps:

[0023] Step 1: uniformly mix thiourea, a polyamine curing agent, and a super absorbent resin in a mass ratio of 1.0:6.0-9.0:3.5-5.0, and condense and reflux for 30-60 minutes at 100-130° C. to obtain a modified mixture; the polyamine curing agent is a phenalkamine curing agent, a fatty amine curing agent, or an aromatic amine curing agent; and the super absorbent resin is a polyacrylate having a particle size of 100-300 meshes;

[0024] Step 2: The modified mixture obtained in step 1 is naturally precipitated. The upper liquid is a thiourea-modified polyamine epoxy curing agent, which is recorded as component A. The precipitate is an amine-modified super absorbent resin. The two are separated by filtration, and the precipitate is washed with ethanol in an amount of 1 to 3 times the mass of the precipitate. The precipitate is dried at a temperature of 60 to 80° C. for 10 hours and ground to obtain a solid amine-modified super absorbent resin, which is recorded as component B.

[0025] Step 3: Add 20 to 30 parts of component A and 15 to 55 parts of component B obtained in step 2 to the epoxy resin system, wherein the epoxy resin system includes 100 parts of epoxy resin, 60 to 80 parts of toughening agent, 10 to 20 parts of active diluent, and 3 to 7 parts of accelerator, and stir the mixture evenly to obtain a solid-liquid double-modified epoxy resin-based anti-collapse plugging agent. The solid-liquid double-modified epoxy resin-based anti-collapse plugging agent needs to be ready for use and used within 10 minutes.

[0026] The epoxy resin molecule contains two or more epoxy groups, and the epoxy resin is any one of bisphenol A epoxy resin, novolac epoxy resin, and glycidylamine epoxy resin; the toughening agent is any one of polyurethane toughening resin and carboxyl-terminated nitrile rubber; the active diluent is glycidyl ether, including any one of benzyl glycidyl ether and butanediol diglycidyl ether; and the accelerator is any one of triethylbenzyl ammonium chloride and 2,4,6-tris(dimethylaminomethyl)phenol.

[0027] Example 1

[0028] First, 10 g of thiourea, 60 g of aliphatic amine curing agent (polyetheramine, D230) and 35 g of highly absorbent resin sodium polyacrylate (100 mesh) were mixed evenly, and refluxed at 100° C. for 30 min to obtain a modified mixture;

[0029] After cooling to room temperature, the modified mixture was allowed to naturally precipitate. The upper liquid layer was the thiourea-modified polyamine epoxy curing agent (Component A), and the precipitate was the amine-modified superabsorbent resin. The two were separated by filtration and the precipitate was washed with ethanol (1:1 ethanol weight) and dried at 60°C for 10 hours to obtain the solid amine-modified superabsorbent resin sodium polyacrylate (Component B).

[0030] Add 20 parts of thiourea-modified polyamine epoxy curing agent (component A) and 15 parts of solid amine-modified highly absorbent resin sodium polyacrylate (component B) to an epoxy resin system containing 100 parts of epoxy resin E51, 60 parts of carboxyl-terminated nitrile rubber, 10 parts of butanediol diglycidyl ether, and 3 parts of 2,4,6-tris(dimethylaminomethyl)phenol, and stir evenly at room temperature to obtain a solid-liquid dual-modified epoxy resin-based anti-collapse plugging agent.

[0031] Example 2

[0032] First, 10 g of thiourea, 80 g of phenalkamine T31 and 45 g of highly absorbent resin sodium polyacrylate (200 mesh) were mixed evenly, and refluxed at 120° C. for 40 min to obtain a modified mixture;

[0033] After cooling to room temperature, the modified mixture was allowed to naturally precipitate. The upper liquid layer was the thiourea-modified polyamine epoxy curing agent (Component A), and the precipitate was the amine-modified superabsorbent resin. The two were separated by filtration and the precipitate was washed with ethanol (the amount of ethanol was twice the weight of the precipitate). The precipitate was dried at 70°C for 10 hours to obtain the solid amine-modified superabsorbent resin sodium polyacrylate (Component B).

[0034] Add 25 parts of thiourea-modified polyamine epoxy curing agent (component A) and 55 parts of solid amine-modified highly absorbent resin sodium polyacrylate (component B) to an epoxy resin system containing 100 parts of epoxy resin E51, 70 parts of carboxyl-terminated nitrile rubber, 15 parts of butanediol diglycidyl ether, and 5 parts of 2,4,6-tris(dimethylaminomethyl)phenol, and stir evenly at room temperature to obtain a solid-liquid dual-modified epoxy resin-based anti-collapse plugging agent.

[0035] Example 3

[0036] First, 10 g of thiourea, 90 g of aromatic amine curing agent (diaminodiphenylmethane, DDM) and 50 g of highly absorbent resin sodium polyacrylate (300 mesh) were mixed evenly, and refluxed at 130° C. for 60 min to obtain a modified mixture;

[0037] After cooling to room temperature, the modified mixture was allowed to naturally precipitate. The upper liquid layer was the thiourea-modified polyamine epoxy curing agent (Component A), and the precipitate was the amine-modified superabsorbent resin. The two were separated by filtration and the precipitate was washed with ethanol (3 times the amount of ethanol) and dried at 80°C for 10 hours to obtain the solid amine-modified superabsorbent resin sodium polyacrylate (Component B).

[0038] 30 parts of thiourea-modified polyamine epoxy curing agent (component A) and 35 parts of solid amine-modified highly absorbent resin sodium polyacrylate (component B) are added to an epoxy resin system containing 100 parts of epoxy resin E51, 80 parts of carboxyl-terminated nitrile rubber, 20 parts of butanediol diglycidyl ether, and 7 parts of 2,4,6-tris(dimethylaminomethyl)phenol, and stirred evenly at room temperature to obtain a solid-liquid dual-modified epoxy resin-based anti-collapse plugging agent.

[0039] Comparative Example 1

[0040] First, 10g of thiourea and 80g of phenalkamine (T31) were mixed evenly and refluxed at 120°C for 40 minutes to obtain a thiourea-modified polyamine epoxy curing agent. 25 parts of the thiourea-modified polyamine epoxy curing agent were added to an epoxy resin system containing 100 parts of epoxy resin E51, 70 parts of carboxyl-terminated nitrile rubber, 15 parts of butanediol diglycidyl ether, and 5 parts of 2,4,6-tris(dimethylaminomethyl)phenol, and stirred evenly at room temperature to obtain an epoxy resin plugging agent.

[0041] The present invention utilizes a laboratory self-assembled plugging agent anti-collapse performance testing device (such as Figure 2 (as shown) the pressure-bearing and leak-proofing ability of the material was evaluated: first, a plastic tube with an opening at one end and a diameter of 10 mm was opened, and three drainage holes with a diameter of 1.5 mm were opened at the bottom. The leak-proof agent and sand were filled in the lower part of the pipe in a mass ratio of 1:3, and the sand column height was 5 cm. Finally, water was injected into the top of the pipe (the water column height was 3 cm). The plastic tube was connected to a pressure pump and pressurized. The changes in the system pressure were observed in real time, and the degree of collapse of the leak-proof agent below the pipe was observed in time, and the maximum pressure-bearing value of the leak-proof agent was recorded. As shown in Table 1, in Comparative Example 1 (amine-modified superabsorbent resin without solidification), the maximum pressure-bearing value of the sample was 0.0125 MPa. When a solid-liquid dual-modified epoxy resin-based leak-proof agent was used, the pressure-bearing value of the sample in Examples 1 to 3 could be increased to 2-24 times that of Comparative Example 1. It should be noted that the anti-collapse pressure value measured in this experiment is limited by the scale of the experimental model, and the pressure-bearing performance in actual application may be greater.

[0042] Table 1 Maximum pressure bearing value of epoxy resin-based plugging agent in anti-collapse test

[0043] Comparative Example 1 Example 1 Example 2 Example 3 0.0125MPa 0.025MPa 0.3MPa 0.2MPa

[0044] The above-described embodiments merely represent specific implementations of the present invention. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art would be able to make various modifications and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the appended claims.

Claims

1. A method for preparing a solid-liquid dual-modified epoxy resin-based anti-collapse plugging agent, characterized in that: Please follow the steps below to implement it: Step 1: uniformly mix thiourea, a polyamine curing agent, and a super absorbent resin, and react under condensation reflux at 100 to 130° C. for 30 to 60 minutes to obtain a modified mixture; Step 2: The modified mixture obtained in step 1 is naturally precipitated. The upper liquid is the thiourea-modified polyamine epoxy curing agent, which is recorded as component A. The precipitate is the amine-modified super absorbent resin. The two are separated by filtration, and the precipitate is washed with ethanol, dried, and ground to obtain a solid amine-modified super absorbent resin, which is recorded as component B. Step 3: Add component A and component B obtained in step 2 to the epoxy resin system, which includes epoxy resin, toughening agent, active diluent, and accelerator, and stir the mixture evenly to obtain a solid-liquid dual-modified epoxy resin-based anti-collapse plugging agent.

2. The method for preparing a solid-liquid dual-modified epoxy resin-based anti-collapse plugging agent according to claim 1, characterized in that: The polyamine curing agent in step 1 is a phenalkamine curing agent, a fatty amine curing agent or an aromatic amine curing agent.

3. The method for preparing a solid-liquid dual-modified epoxy resin-based anti-collapse plugging agent according to claim 1, characterized in that: The super absorbent resin in step 1 is polyacrylate, and the particle size is 100-300 mesh.

4. The method for preparing a solid-liquid dual-modified epoxy resin-based anti-collapse plugging agent according to claim 1, characterized in that: The mass ratio of thiourea, polyamine curing agent and super absorbent resin in step 1 is 1.0:6.0-9.0:3.5-5.

0.

5. The method for preparing a solid-liquid dual-modified epoxy resin-based anti-collapse plugging agent according to claim 1, characterized in that: The amount of ethanol used in step 2 is 1 to 3 times the mass of the precipitate, the drying temperature is 60 to 80° C., and the drying time is 10 h.

6. The method for preparing a solid-liquid dual-modified epoxy resin-based anti-collapse plugging agent according to claim 1, characterized in that: The epoxy resin molecule in step 3 contains two or more epoxy groups, and the epoxy resin is any one of bisphenol A epoxy resin, novolac epoxy resin, and glycidylamine epoxy resin; the toughening agent is any one of polyurethane toughening resin and carboxyl-terminated nitrile rubber; the reactive diluent is a glycidyl ether, including any one of benzyl glycidyl ether and butanediol diglycidyl ether; the accelerator is any one of triethylbenzyl ammonium chloride and 2,4,6-tris(dimethylaminomethyl)phenol.

7. The method for preparing a solid-liquid dual-modified epoxy resin-based anti-collapse plugging agent according to claim 1, characterized in that: In step 3, the components A are 20 to 30 parts, the components B are 15 to 55 parts, the epoxy resin is 100 parts, the toughening agent is 60 to 80 parts, the reactive diluent is 10 to 20 parts, and the accelerator is 3 to 7 parts.

8. A solid-liquid double-modified epoxy resin-based anti-collapse plugging agent prepared according to the method for preparing a solid-liquid double-modified epoxy resin-based anti-collapse plugging agent according to any one of claims 1 to 7.

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