Anti-mud polycarboxylate water reducer and preparation method thereof

Abstract

The present invention discloses a mud-resistant polycarboxylate water-reducing agent and a preparation method thereof, belonging to the field of concrete. The raw materials for preparing the mud-resistant polycarboxylate water-reducing agent, calculated in molar percentage, include: 15% to 25% unsaturated polyether macromonomer, 60% to 80% acrylic acid, 1% to 10% unsaturated phosphite amphoteric monomer, 0.5% to 5% initiator, 0.01% to 0.5% chain transfer agent, and the balance being water. The mud-resistant polycarboxylate water-reducing agent provided by the present invention has good dispersibility and dispersion retention, thus possessing excellent mud resistance.

Description

Technical Field

[0001] The present invention relates to the field of concrete, and in particular to an anti-mud type polycarboxylate water reducer and a preparation method thereof. Background Art

[0002] In the actual production and application of concrete, it is found that with the sharp increase in domestic infrastructure projects, a large amount of high-quality concrete raw materials have been consumed. In addition, with the increasing pressure on environmental protection, the amount of raw materials mined has gradually decreased and the price has risen year by year. Therefore, more and more concrete construction projects are forced to use sand and gravel of poor quality and high mud content.

[0003] Polycarboxylate superplasticizers (PCEs) are highly sensitive to the mud content of sand and gravel in concrete, primarily affecting the workability of fresh concrete. When the sand and gravel contain no or low amounts of mud, PCEs exhibit excellent performance. However, once the mud content increases, their performance declines significantly. Not all mud components in sand and gravel have an inhibitory effect on PCEs. Numerous studies have shown that the primary factor affecting the effect of clay minerals in the mud is the clay. Clays are mostly layered silicate minerals, characterized by interlamellar domains between the layers that make up their unit structure. Upon absorbing water, these minerals expand and increase in size, drawing in water and polycarboxylate molecules. This further reduces the amount of water in the system and causes the clay to occupy the polycarboxylate superplasticizer molecules used to disperse cement particles, thus affecting the workability of the entire concrete system.

[0004] As the mud content in sand and gravel increases, polycarboxylate superplasticizers are adsorbed in large quantities during use, which reduces the dispersibility and dispersion retention of the polycarboxylate superplasticizers, resulting in a decrease in the workability of concrete. Therefore, there is a lack of polycarboxylate superplasticizers suitable for sand and gravel with high mud content. Summary of the Invention

[0005] In view of the above-mentioned deficiencies in the prior art, the present invention proposes a mud-resistant polycarboxylate water-reducing agent and a preparation method thereof to solve the current problem of lack of a polycarboxylate water-reducing agent suitable for sand and gravel with high mud content.

[0006] To achieve the above object, the present invention provides an anti-mud polycarboxylate water reducer. The raw materials for preparing the anti-mud polycarboxylate water reducer include, by mole percentage, 15% to 25% of an unsaturated polyether macromonomer, 60% to 80% of acrylic acid, 1% to 10% of an unsaturated phosphite amphoteric monomer, 0.5% to 5% of an initiator, 0.01% to 0.5% of a chain transfer agent, and the balance being water.

[0007] Optionally, the structure of the unsaturated phosphite amphoteric monomer is as shown in formula (I): (I).

[0008] Optionally, the molecular weight of the unsaturated polyether macromonomer is 1000-3000.

[0009] Optionally, the unsaturated polyether macromonomer includes at least one of allyl polyoxyethylene ether, isobutylene alcohol polyoxyethylene ether, and isopentyl polyoxyethylene ether.

[0010] Optionally, the initiator includes at least one of hydrogen peroxide, ammonium persulfate or potassium persulfate.

[0011] Optionally, the chain transfer agent is selected from at least one of mercaptopropionic acid, thioglycolic acid, sodium methyl propylene sulfonate or sodium propylene sulfonate.

[0012] Optionally, the chemical structural formula of the anti-mud polycarboxylate water-reducing agent is as shown in formula (II):

[0013] (II), wherein R1 is -H or -CH3; R2 is -CH2- or -CH2CH2-; y, z, m, and n are all non-zero integers.

[0014] To achieve the above object, the present invention further provides a method for preparing the above-mentioned anti-mud polycarboxylate water-reducing agent, comprising the following steps: S1: copolymerizing the unsaturated polyether macromonomer, acrylic acid, unsaturated phosphite amphoteric monomer, initiator and chain transfer agent with water to obtain a copolymer solution; S2: cooling the copolymer solution, and then adjusting the pH value with an alkaline substance to obtain a clear solution, which is the anti-mud polycarboxylate water-reducing agent.

[0015] Optionally, the copolymerization reaction is carried out at 50° C. to 70° C. for 3 hours to 5 hours.

[0016] Optionally, the cooling is to below 40°C.

[0017] The beneficial effects of the present invention are as follows: the anti-mud polycarboxylate water-reducer provided by the present invention contains both phosphite and quaternary ammonium salt groups on the molecular side chains, has stronger adsorption capacity than existing polycarboxylate water-reducers, can effectively resist sulfate in cement, and at the same time, the positively charged groups carried by the quaternary ammonium salt groups adsorb soil, reducing the influence of soil on cement particles, greatly improving the dispersibility and fluidity of the polycarboxylate water-reducer, and the phosphite structure can also change the crystal morphology of initially formed ettringite, thereby improving the slump retention performance; at the same time, the synergistic effect of the carboxyl, phosphite, hydroxyl and quaternary ammonium salt groups contained in the water-reducer molecular chain is beneficial to the wetting and adsorption of the cement and soil particle surfaces and the relative lubrication between aggregate particles, so that the anti-mud polycarboxylate water-reducer has good dispersibility and dispersion retention, and exhibits good mud resistance. DETAILED DESCRIPTION

[0018] In order to make the purpose, 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. It should be understood that the following embodiments are only used to explain the present invention and are not used to limit the present invention.

[0019] Unless defined otherwise, all technical and scientific terms used herein have the common meaning in the art to which the claimed subject matter belongs.

[0020] In the actual production and application of concrete, it is found that with the sharp increase in domestic infrastructure projects, a large amount of high-quality concrete raw materials have been consumed. In addition, with the increasing pressure on environmental protection, the amount of raw materials mined has gradually decreased and the price has risen year by year. Therefore, more and more concrete construction projects are forced to use sand and gravel of poor quality and high mud content.

[0021] Polycarboxylate superplasticizers (PCEs) are highly sensitive to the mud content of sand and gravel in concrete, primarily affecting the workability of fresh concrete. When the sand and gravel contain no or low amounts of mud, PCEs exhibit excellent performance. However, once the mud content increases, their performance declines significantly. Not all mud components in sand and gravel have an inhibitory effect on PCEs. Numerous studies have shown that the primary factor affecting the effect of clay minerals in the mud is the clay. Clays are mostly layered silicate minerals, characterized by interlamellar domains between the layers that make up their unit structure. Upon absorbing water, these minerals expand and increase in size, drawing in water and polycarboxylate molecules. This further reduces the amount of water in the system and causes the clay to occupy the polycarboxylate superplasticizer molecules used to disperse cement particles, thus affecting the workability of the entire concrete system.

[0022] As the mud content in sand and gravel increases, polycarboxylate superplasticizers are adsorbed in large quantities during use, which reduces the dispersibility and dispersion retention of the polycarboxylate superplasticizers, resulting in a decrease in the workability of concrete. Therefore, there is a lack of polycarboxylate superplasticizers suitable for sand and gravel with high mud content.

[0023] To solve the above problems, the present invention proposes an anti-mud polycarboxylate water reducer. The raw materials for preparing the anti-mud polycarboxylate water reducer include, by mole percentage, 15% to 25% of an unsaturated polyether macromonomer, 60% to 80% of acrylic acid, 1% to 10% of an unsaturated phosphite amphoteric monomer, 0.5% to 5% of an initiator, 0.01% to 0.5% of a chain transfer agent, and the balance being water.

[0024] The anti-mud polycarboxylate water-reducing agent of this scheme is a copolymer prepared by free radical copolymerization of unsaturated polyether macromonomer, unsaturated phosphite amphoteric monomer and acrylic acid as raw materials in the presence of an initiator and a chain transfer agent.

[0025] The unsaturated polyether macromonomer serves as the backbone of the copolymer, providing molecular stability and flexibility, which helps improve the adsorption capacity and dispersibility of the water reducer. The steric hindrance of the macromonomer helps disperse the water reducer between cement particles, preventing cement flocculation and thus improving the fluidity of the concrete.

[0026] Acrylic acid is the primary monomer. The carboxyl functional groups of acrylic acid form an adsorption layer on the surface of cement particles, enhancing the water-reducing effect. A high content of acrylic acid helps increase the acidity of the water-reducing agent, promotes cement hydration, and improves the early strength of concrete.

[0027] Unsaturated phosphite amphoteric monomers introduce phosphorus, providing zwitterionic properties and enhancing the water reducer's interaction with cement and soil. The amphoteric monomers may improve the water reducer's mud resistance and dispersion stability by forming more chemical adsorption and physical entanglement.

[0028] The initiator initiates the free radical copolymerization reaction, controls the initiation and rate of the polymerization reaction, and ensures the smooth progress of the reaction.

[0029] Chain transfer agents regulate the molecular weight and molecular weight distribution of polymers, preventing the loss of solubility and dispersibility caused by excessively high molecular weights. Chain transfer agents can control polymerization reactions, reduce overpolymerization, and ensure the stability and long-term storage performance of water reducers.

[0030] Through a rational raw material ratio and polymerization process, the resulting anti-mud polycarboxylate water reducer exhibits excellent mud resistance while maintaining high water-reducing performance. The polymer's molecular structure design helps improve its adsorption capacity on the surface of cement particles, reducing the impact of clay and other soils on the water-reducing effect. The high content of acrylic acid imparts strong acidity to the water reducer, promoting cement hydration and improving the early strength and workability of concrete. The introduction of an unsaturated phosphite amphoteric monomer enhances the water reducer's interaction with both cement and soil, improving its mud resistance and stability. Precise control of the initiator and chain transfer agent ensures the polymer's molecular weight and molecular weight distribution, thereby guaranteeing the water reducer's solubility, dispersibility, and storage stability.

[0031] Furthermore, the structure of the unsaturated phosphite amphoteric monomer is shown in formula (I): (I). The introduction of phosphate groups effectively weakens the adsorption of mud on carboxyl groups, thereby improving the water reducer's tolerance in materials with high mud content. This addresses the performance degradation of traditional polycarboxylate water reducers in the presence of mud. Furthermore, the phosphate groups have a stronger ability to complex with calcium ions in cement, which improves the water reducer's dispersibility and enhances the concrete's fluidity and workability. Furthermore, the phosphite structure of this solution also helps alter the initial crystal morphology of ettringite, thereby improving slump retention.

[0032] Furthermore, the molecular weight of the unsaturated polyether macromonomer is 1000 to 3000. Unsaturated polyether macromonomers within this molecular weight range have high polymerization reactivity. More preferably, the molecular weight of the unsaturated polyether macromonomer is 2200 to 2500. More preferably, the molecular weight of the unsaturated polyether macromonomer is 2400.

[0033] Furthermore, the unsaturated polyether macromonomer comprises at least one of allyl polyoxyethylene ether, isobutylene alcohol polyoxyethylene ether, and isopentyl polyoxyethylene ether. During the polymerization process, these unsaturated polyether macromonomers can affect the molecular weight, molecular weight distribution, and regularity of the molecular structure of the final polymer due to their different carbon chain lengths and structures. Different macromonomers can provide different steric hindrances and hydrophilic / hydrophobic balances, which are crucial for the adsorption and dispersion effects of the water reducer on cement particles. By rationally matching these macromonomers, a polycarboxylate water reducer with excellent comprehensive properties can be obtained, such as high water reduction rate, good cement adaptability, low shrinkage, high durability, etc., and these macromonomers have high double bond retention rates and good activity, making them suitable for preparing the polycarboxylate water reducer of this solution.

[0034] Furthermore, the initiator includes at least one of hydrogen peroxide, ammonium persulfate, or potassium persulfate. These initiators can effectively decompose and generate free radicals to initiate the polymerization reaction of the polycarboxylate water-reducing agent. They have a wide temperature range, good stability, and high safety. Furthermore, the decomposition rate and reaction conditions of these initiators are relatively easy to control, which helps to achieve the desired degree of polymerization and molecular weight distribution.

[0035] Furthermore, the chain transfer agent is selected from at least one of mercaptopropionic acid, thioglycolic acid, sodium methacrylic acid or sodium propylene sulfonate.

[0036] Furthermore, the chemical structural formula of the anti-mud polycarboxylate water-reducing agent is as shown in formula (II):

[0037] (II), wherein R1 is -H or -CH3; R2 is -CH2- or -CH2CH2-; and y, z, m, and n are all non-zero integers. This solution contains both phosphite and quaternary ammonium salt groups on its molecular side chains, resulting in a stronger adsorption capacity than existing polycarboxylate water reducers and effective resistance to sulfate in cement. The positively charged groups carried by the quaternary ammonium salt groups adsorb soil, reducing the impact of soil on cement particles and significantly improving the dispersibility and fluidity of the polycarboxylate water reducer. The phosphite structure can also alter the initial crystal morphology of ettringite, thereby improving its slump retention performance. Furthermore, the synergistic effect of the carboxyl, phosphite, hydroxyl, and quaternary ammonium salt groups on the water reducer's molecular chain facilitates wetting and adsorption on the surfaces of cement and soil particles, as well as relative lubrication between aggregate particles. This results in the anti-mud polycarboxylate water reducer exhibiting excellent dispersibility and dispersion retention, demonstrating superior mud resistance.

[0038] In some embodiments, R1 is -CH3 and R2 is -CH2CH2-.

[0039] To solve the above problems, the present invention further proposes a method for preparing the above-mentioned anti-mud polycarboxylate water-reducing agent, comprising the following steps:

[0040] S1: copolymerizing the unsaturated polyether macromonomer, acrylic acid, unsaturated phosphite amphoteric monomer, initiator and chain transfer agent with water to obtain a copolymer solution;

[0041] S2: Cooling the copolymer solution and then adjusting the pH with an alkaline substance to obtain a clear solution, which is the anti-mud polycarboxylate water-reducing agent. In some embodiments, the pH is adjusted to a range of 6.0-7.0.

[0042] Furthermore, the copolymerization reaction is carried out at 50°C to 70°C for 3 to 5 hours. In a further preferred embodiment, the copolymerization reaction temperature in S1 is 57 to 60°C.

[0043] Furthermore, the cooling is to below 40°C.

[0044] The present invention's method for preparing a mud-resistant polycarboxylate water-reducing agent achieves high performance and improved stability through precise control of copolymerization reaction conditions and pH adjustment. The method involves conducting the copolymerization reaction at 50°C to 70°C for 3 to 5 hours, ensuring polymer uniformity and activity. Subsequently, the solution is cooled to below 40°C and the pH adjusted to 6.0-7.0 to obtain a clear and stable water-reducing agent solution. This water-reducing agent exhibits excellent mud-resistant properties and enhanced interaction with cement and soil, while maintaining environmental friendliness and ease of operation.

[0045] The present invention will be further described in detail below with reference to specific embodiments.

[0046] Example 1:

[0047] In a 1000mL four-necked round-bottom flask equipped with a thermometer, an electric stirrer, a constant temperature electric heating mantle, and a peristaltic pump, 250g of water and 300g of a polyether macromonomer APEG (the molecular weight of the APEG used is 2400) were added, stirred and heated to 58°C. After uniform dissolution, a mixed solution of 3.9g of hydrogen peroxide and 16g of water was directly added and stirred for 10 minutes to fully dissolve. A mixed aqueous solution consisting of 45g of acrylic acid, 15g of an unsaturated phosphite amphoteric monomer, and 76g of water and a mixed solution consisting of 0.60g of ascorbic acid, 1.6g of mercaptopropionic acid, and 90g of water were added dropwise over 3 hours, and the temperature was maintained between 57-60°C. After the addition was completed, the reaction was continued for 2 hours, then the temperature was lowered to 30-35°C, and 30% sodium hydroxide solution and dilution water were added to obtain an anti-mud polycarboxylate water reducer with a pH of 6-7 and a concentration of about 40%. Its structural formula is: .

[0048] Example 2:

[0049] In a 1000mL four-necked round-bottom flask equipped with a thermometer, an electric stirrer, a constant temperature electric heating mantle, and a peristaltic pump, 250g of water and 300g of a polyether macromonomer HPEG (the molecular weight of the HPEG used is 2400) were added, stirred and heated to 58°C. After uniform dissolution, a mixed solution of 3.9g of hydrogen peroxide and 16g of water was directly added and stirred for 10 minutes to fully dissolve. A mixed aqueous solution consisting of 45g of acrylic acid, 15g of an unsaturated phosphite amphoteric monomer, and 76g of water and a mixed solution consisting of 0.60g of ascorbic acid, 1.6g of mercaptopropionic acid, and 90g of water were added dropwise over 3 hours, and the temperature was maintained between 57-60°C. After the addition was completed, the reaction was continued for 2 hours, then the temperature was lowered to 35-40°C, and 30% sodium hydroxide solution and dilution water were added to obtain an anti-mud polycarboxylate water reducer with a pH of 6-7 and a concentration of about 40%. Its structural formula is:

[0050] .

[0051] Example 3:

[0052] In a 1000mL four-necked round-bottom flask equipped with a thermometer, an electric stirrer, a constant temperature electric heating mantle, and a peristaltic pump, 250g of water and 300g of a polyether macromonomer TPEG (the molecular weight of TPEG used is 2400) were added, stirred and heated to 58°C. After uniform dissolution, a mixed solution of 3.9g of hydrogen peroxide and 16g of water was directly added and stirred for 10 minutes to fully dissolve. A mixed aqueous solution consisting of 45g of acrylic acid, 15g of an unsaturated phosphite amphoteric monomer, and 76g of water and a mixed solution consisting of 0.60g of ascorbic acid, 1.6g of mercaptopropionic acid, and 90g of water were added dropwise over 3 hours, and the temperature was maintained between 57-60°C. After the addition was completed, the reaction was continued for 2 hours, then the temperature was lowered to 35-40°C, and 30% sodium hydroxide solution and dilution water were added to obtain an anti-mud polycarboxylate water reducer with a pH of 6-7 and a concentration of about 40%. Its structural formula is:

[0053] .

[0054] Example 4:

[0055] In a 1000mL four-necked round-bottom flask equipped with a thermometer, an electric stirrer, a constant temperature electric heating mantle, and a peristaltic pump, 250g of water and 300g of a polyether macromonomer TPEG (the molecular weight of TPEG used is 2400) were added, stirred and heated to 58°C. After uniform dissolution, a mixed solution of 4.6g of hydrogen peroxide and 16g of water was directly added and stirred for 10 minutes to fully dissolve. A mixed aqueous solution consisting of 40g of acrylic acid, 20g of an unsaturated phosphite amphoteric monomer, and 80g of water and a mixed solution consisting of 0.53g of ascorbic acid, 1.44g of mercaptopropionic acid, and 80g of water were added dropwise over 3 hours, and the temperature was maintained between 57-60°C. After the addition was completed, the reaction was continued for 2 hours, then the temperature was lowered to 35-40°C, and 30% sodium hydroxide solution and dilution water were added to obtain an anti-mud polycarboxylate water reducer with a pH of 6-7 and a concentration of about 40%. Its structural formula is:

[0056] Comparative Example 1

[0057] In a 1000mL four-necked round-bottom flask equipped with a thermometer, electric stirrer, electric heating mantle, and peristaltic pump, 250g of water and 300g of a polyether macromonomer HPEG (HPEG having a molecular weight of 2400) were added. After stirring and dissolving uniformly, 3.9g of a hydrogen peroxide solution was directly added and stirred for 10 minutes to fully dissolve. A mixed aqueous solution consisting of 45g of acrylic acid and 60g of water and a mixed solution consisting of 1.6g of ascorbic acid, 2.0g of mercaptopropionic acid, and 60g of water were added dropwise over 3 hours and 3.5 hours, respectively, at room temperature. After the addition was complete, the reaction was continued for 1 hour, and 30% sodium hydroxide solution and dilution water were added to obtain a conventional polycarboxylate water-reducing agent with a pH of 6-7 and a concentration of approximately 40%. Its structural formula is:

[0058] .

[0059] Comparative Example 2

[0060] In a 1000mL four-necked round-bottom flask equipped with a thermometer, electric stirrer, electric heating mantle, and peristaltic pump, 250g of water and 300g of a polyether macromonomer, TPEG, with a molecular weight of 2400, were added. After stirring and dissolving uniformly, a mixed solution of 3.9g of hydrogen peroxide and 16g of water was directly added and stirred for 10 minutes to fully dissolve. A mixed aqueous solution consisting of 42g of acrylic acid and 60g of water and a mixed solution consisting of 1.6g of ascorbic acid, 2.0g of mercaptopropionic acid, and 60g of water were added dropwise over 2 hours and 2.5 hours, respectively, at room temperature. After the addition was complete, the reaction was continued for 1.5 hours, and 30% sodium hydroxide solution and dilution water were added to obtain a conventional polycarboxylate water-reducing agent with a pH of 6-7 and a concentration of approximately 40%. Its structural formula is:

[0061] .

[0062] Furthermore, the flow properties of the pastes in Examples 1-4 and Comparative Example 1 were tested according to GB / T 8077-2012, "Test Method for Homogeneity of Concrete Admixtures," using the standard cement. The test results are shown in Table 1. The slump and spread of the initial and 60-minute tests were also tested in accordance with GB / T 50080-2002, "Standard for Test Methods for Performance of Ordinary Concrete Mixtures." The mix proportions for the C30 manufactured sand concrete are shown in Table 2: Conch Cement, manufactured sand, Grade II fly ash, fineness modulus of 3.2, stone dust content of 7.2%, MB value of 2.1, with the stone dust primarily composed of mud. The concrete test results are shown in Table 3.

[0063] Table 1 Cement paste fluidity test results

[0064]

[0065] Table 2 Mix proportion of C30 machine-made sand concrete

[0066]

[0067] Table 3 Concrete test results

[0068]

[0069] The data in Table 1 show that, at the same water-reducing agent dosage and bentonite content, the initial fluidity of Examples 1-4 (the anti-mud polycarboxylate water-reducing agents of the present invention) is approximately 260 mm, while that of Comparative Examples 1-2 (conventional polycarboxylate water-reducing agents) is approximately 220 mm. The cement paste fluidity of Examples 1-4 is approximately 190 mm after 90 minutes, while that of Comparative Examples 1-2 is completely fluid after 90 minutes. This demonstrates that the anti-mud polycarboxylate water-reducing agents of the present invention exhibit excellent water-reducing, slump-retention, and anti-mud properties, significantly outperforming conventional polycarboxylate water-reducing agents.

[0070] As can be seen from Table 3, Examples 1 to 4 (the anti-mud polycarboxylate water reducer of the present invention) have a large water reduction rate and good slump retention performance, and their performance is significantly better than that of Comparative Examples 1 to 2 (conventional polycarboxylate water reducers).

[0071] The above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Those skilled in the art will readily appreciate that the present invention is susceptible to various modifications and variations. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of the present invention.

Claims

1. An anti-mud type polycarboxylate water reducer, characterized in that, The raw materials for preparing the anti-mud polycarboxylate water-reducing agent include, by mole percentage, 15% to 25% of an unsaturated polyether macromonomer, 60% to 80% of acrylic acid, 1% to 10% of an unsaturated phosphite amphoteric monomer, 0.5% to 5% of an initiator, 0.01% to 0.5% of a chain transfer agent, and the balance being water; The structure of the unsaturated phosphite amphoteric monomer is shown in formula (I): (I); The chemical structural formula of the anti-mud polycarboxylate water-reducing agent is as shown in formula (II): (II), Wherein, R1 is -H or -CH3; R2 is -CH2- or -CH2CH2-; y, z, m, and n are all non-zero integers; The preparation method of the anti-mud polycarboxylate water-reducing agent comprises the following steps: S1: copolymerizing the unsaturated polyether macromonomer, acrylic acid, unsaturated phosphite amphoteric monomer, initiator and chain transfer agent with water to obtain a copolymer solution; S2: cooling the copolymer solution, and then adjusting the pH value with an alkaline substance to obtain a clear solution, which is the anti-mud polycarboxylate water-reducing agent; The copolymerization reaction is carried out at 50° C. to 70° C. for 3 to 5 hours.

2. The anti-mud polycarboxylate water reducer according to claim 1, characterized in that: The molecular weight of the unsaturated polyether macromonomer is 1000-3000.

3. The anti-mud type polycarboxylate water reducer according to claim 1, characterized in that: The unsaturated polyether macromonomer includes at least one of allyl polyoxyethylene ether, isobutylene alcohol polyoxyethylene ether and isopentyl polyoxyethylene ether.

4. The anti-mud type polycarboxylate water reducer according to claim 1, characterized in that: The initiator includes at least one of hydrogen peroxide, ammonium persulfate or potassium persulfate.

5. The anti-mud type polycarboxylate water reducer according to claim 1, characterized in that: The chain transfer agent is selected from at least one of mercaptopropionic acid, thioglycolic acid, sodium methacrylic acid or sodium propylene sulfonate.

6. A method for preparing the anti-mud polycarboxylate water-reducing agent according to any one of claims 1 to 5, characterized in that: The following steps are involved: S1: copolymerizing the unsaturated polyether macromonomer, acrylic acid, unsaturated phosphite amphoteric monomer, initiator and chain transfer agent with water to obtain a copolymer solution; S2: cooling the copolymer solution, and then adjusting the pH value with an alkaline substance to obtain a clear solution, which is the anti-mud polycarboxylate water-reducing agent; The copolymerization reaction is carried out at 50° C. to 70° C. for 3 to 5 hours.

7. The method for preparing the anti-mud polycarboxylate water-reducing agent according to claim 6, wherein: The cooling is to below 40°C.

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