Anti-mud polycarboxylate water reducing agent and preparation method and application thereof

Abstract

This invention relates to the field of concrete admixtures, specifically to an anti-mud polycarboxylate superplasticizer, its preparation method, and its application. The anti-mud polycarboxylate superplasticizer provided by this invention comprises, by weight, the following raw materials: 100-180 parts of unsaturated polyether monomer, 5-10 parts of unsaturated carboxylic acid monomer, 2-5 parts of air-entraining monomer, 5-10 parts of anti-mud monomer, 10-20 parts of oxidant, 0.4-0.6 parts of reducing agent, 5-7 parts of chain transfer agent, and 150-300 parts of water; the air-entraining monomer and the anti-mud monomer have specific structures. The simultaneous introduction of specific anti-mud monomers and air-entraining monomers into the anti-mud polycarboxylate superplasticizer of this invention not only reduces clay adsorption but also provides better dispersibility and anti-mud effect at lower dosages, increasing the overall workability of concrete and improving concrete performance.

Description

Technical Field

[0001] This invention relates to the field of concrete admixtures, specifically to an anti-mud polycarboxylate superplasticizer, its preparation method, and its application. Background Technology

[0002] With the rapid development of the construction industry, concrete, as one of the most important building materials, has received increasing attention for performance optimization and cost control. Water-reducing agents, as core admixtures in concrete, can significantly improve the fluidity and strength development of the mixture, playing a crucial role in improving project quality and construction efficiency. However, in actual engineering projects, the problem of excessive clay content in sand and gravel aggregates is widespread. Especially with the increasing depletion of natural sand resources and the widespread application of alternative materials such as manufactured sand and recycled aggregates, the introduction of clay minerals into the aggregates has been further exacerbated.

[0003] The layered crystal structure of clay minerals (such as montmorillonite and kaolin) gives them strong adsorption and expansion properties, which have a particularly significant impact on traditional polycarboxylate superplasticizers (PCE). Clay particles adsorb a large number of superplasticizer molecules, resulting in a significant reduction in the effective components that actually act on cement particles, leading to a substantial decrease in their dispersion effect and limited anti-mud effect. Summary of the Invention

[0004] Therefore, the technical problem to be solved by the present invention is to overcome the defects of the existing water-reducing agent, which has poor effect and limited concrete dispersion and anti-mud effect, and thus provide an anti-mud polycarboxylate water-reducing agent, its preparation method and application.

[0005] Therefore, the present invention provides the following technical solution:

[0006] A mud-resistant polycarboxylate superplasticizer, comprising the following raw materials in parts by weight:

[0007] 100-180 parts of unsaturated polyether monomer, 5-10 parts of unsaturated carboxylic acid monomer, 2-5 parts of air-entraining monomer, 5-10 parts of anti-mud monomer, 10-20 parts of oxidant, 0.4-0.6 parts of reducing agent, 5-7 parts of chain transfer agent and 150-300 parts of water.

[0008] The air-entraining unit has the structure shown in Formula I or Formula II:

[0009]

[0010] The anti-mud monomer has the structure shown in Formula III:

[0011]

[0012] in:

[0013] n is an integer selected from 1 to 3;

[0014] R is independently selected from any of the following groups:

[0015] *-H

[0016] The raw materials for preparing the gas-entraining monomer include raw material A and glycidyl methacrylate; raw material A is selected from dodecyl sulfonic acid or dodecylbenzene sulfonic acid.

[0017] The preparation method of the air-entraining monomer includes the following steps:

[0018] Step S11: Dissolve raw material A in a solvent to obtain solution A;

[0019] Step S12: Add a phase transfer catalyst to solution A to obtain solution B;

[0020] Step S13: Glycidyl methacrylate is added to solution B and mixed, then heated to react and obtain the gas-entraining monomer.

[0021] Optionally, the ratio of raw material A to glycidyl methacrylate is 1-3:1, in g / mL.

[0022] Optionally, the mass ratio of the phase transfer catalyst to raw material A is 15-25:1.

[0023] Optionally, the mass ratio of raw material A to solvent is 1:5-15.

[0024] Optionally, in step S11, the solvent is selected from acetone and water, with a volume ratio of acetone to water of 0.5-1:1.

[0025] Optionally, in step S12, the phase transfer catalyst includes at least one of benzyltriethylammonium chloride, tetrabutylammonium bromide, tetrabutylammonium hydrogen sulfate, and hexadecyltrimethylammonium bromide, preferably tetrabutylammonium bromide.

[0026] Optionally, in step S13, glycidyl methacrylate is added to solution B by dropwise addition, with stirring maintained during the dropwise addition process. The dropwise addition time is 7-8 hours, and the temperature of solution B is controlled at 55-65°C. After the dropwise addition is completed, the mixture is heated and stirred at 55-65°C for another 2-3 hours.

[0027] Optionally, step S13 may further include adjusting the pH of the reaction solution to 2-3, extraction, washing, and drying after the reaction is complete.

[0028] Alternatively, the extraction solvent is selected from at least one of ethyl acetate, butyl acetate, and amyl acetate.

[0029] Alternatively, the washing step may be performed using at least one of saturated saline solution, ethanol, or water.

[0030] The preparation method of the anti-mud monomer includes the following steps:

[0031] Step S21: Phosphorus pentoxide is mixed with an organic solvent to obtain a first mixture;

[0032] Step S22: Add unsaturated ester monomers to the first mixture and allow it to react under heat to obtain the anti-mud monomer.

[0033] Optionally, the mass ratio of phosphorus pentoxide to organic solvent is 1:0.5-1.

[0034] Optionally, the mass ratio of phosphorus pentoxide to unsaturated ester monomer is 1:2-3.

[0035] In step S21, the organic solvent is selected from at least one of diethyl ether, 1,2-dichloromethane, 1,2-dichloroethane, acetonitrile, and N,N-dimethylformamide, preferably at least one of 1,2-dichloromethane, 1,2-dichloroethane, and acetonitrile.

[0036] In step S22, the unsaturated ester monomer is selected from at least one of hydroxyethyl acrylate, hydroxypropyl acrylate, and hydroxybutyl acrylate.

[0037] In step S22, the unsaturated ester monomer is added to the first mixture dropwise over a period of 90-120 minutes. The temperature of the first mixture is controlled at 60-70°C. After the addition is complete, the mixture is kept at 60-70°C for 1-2 hours.

[0038] The unsaturated polyether monomer is selected from at least one of vinyl polyethylene glycol ether and isopentenyl alcohol polyoxyethylene ether.

[0039] Optionally, the number average molecular weight of the vinyl polyethylene glycol ether or isopentenyl alcohol polyoxyethylene ether is 1000-3000.

[0040] The unsaturated carboxylic acid monomer is selected from at least one of acrylic acid, methacrylic acid, and maleic anhydride.

[0041] The oxidant is selected from at least one of hydrogen peroxide, sodium peroxide, potassium peroxide, magnesium peroxide, sodium persulfate, ammonium persulfate, sodium dichromate, potassium dichromate, and potassium permanganate.

[0042] The reducing agent is selected from at least one of sodium dioctyl succinate sulfonate, ascorbic acid, sodium formaldehyde sulfoxylate, sodium sulfite, sodium bisulfite, and sodium hypophosphite.

[0043] The chain transfer agent is at least one of thioglycolic acid, sodium hypophosphite, trisodium phosphate, mercaptopropionic acid, mercaptoethanol, and mercaptoacetic acid.

[0044] It also includes 0.01-0.02 parts by weight of a catalyst, wherein the catalyst is ferrous sulfate.

[0045] This invention also provides a method for preparing an anti-mud-type polycarboxylate superplasticizer, comprising the following steps:

[0046] Step S31: Mix unsaturated polyether monomers, oxidant, chain transfer agent and water to obtain the base material;

[0047] Step S32: Mix unsaturated carboxylic acid monomer, anti-mud monomer, air-entraining monomer with water to obtain solution A;

[0048] Step S33: Mix the reducing agent with water to obtain solution B;

[0049] Step S34: Add liquid A and liquid B to the base material, keep it warm and react to obtain the anti-mud polycarboxylate superplasticizer.

[0050] In step S31, the mass ratio of unsaturated polyether monomer to water is 1:1.5-3.

[0051] In step S32, the mass ratio of unsaturated carboxylic acid monomer to water is 1:5-10.

[0052] In step S33, the mass ratio of reducing agent to water is 0.4:80-120.

[0053] Step S31 also includes the step of adding a catalyst.

[0054] In step S34, the droplet addition time of liquid A is 120-160 min, and the droplet addition temperature is 50-70℃; the droplet addition time of liquid B is 140-160 min, and the droplet addition temperature is 50-70℃. After the droplet addition is completed, the reaction is continued at 60-70℃ for 0.5-1.5 h.

[0055] The present invention also provides a concrete comprising the above-described anti-mud polycarboxylate superplasticizer or the anti-mud polycarboxylate superplasticizer prepared by the above-described preparation method.

[0056] The amount of the anti-mud polycarboxylate superplasticizer added is 1.5-2% of the concrete mass.

[0057] The technical solution of this invention has the following advantages:

[0058] 1. This invention provides an anti-mud polycarboxylate superplasticizer, comprising, by weight, the following raw materials: 100-180 parts of unsaturated polyether monomer, 5-10 parts of unsaturated carboxylic acid monomer, 2-5 parts of air-entraining monomer, 5-10 parts of anti-mud monomer, 10-20 parts of oxidant, 0.4-0.6 parts of reducing agent, 5-7 parts of chain transfer agent, and 150-300 parts of water; wherein the air-entraining monomer and anti-mud monomer have specific structures. The simultaneous introduction of specific anti-mud monomers and air-entraining monomers into the anti-mud polycarboxylate superplasticizer of this invention not only reduces clay adsorption and lowers viscosity, but also exhibits better dispersibility and anti-mud effect at lower dosages, increasing the overall workability and cold resistance of concrete, fundamentally improving concrete performance.

[0059] 2. This invention provides an anti-mud polycarboxylate superplasticizer, comprising an air-entraining monomer. The raw materials for preparing the air-entraining monomer include raw material A and glycidyl methacrylate; raw material A is selected from dodecyl sulfonic acid or dodecylbenzene sulfonic acid. Both dodecyl sulfonic acid and dodecylbenzene sulfonic acid in the raw materials possess excellent bubble stability and uniformity, significantly reducing the surface tension of water. During stirring, they form a large number of fine, uniform, and stable microbubbles, preventing internal stress from damaging the concrete structure. Furthermore, due to the simultaneous presence of hydrophilic sulfonate groups and hydrophobic alkyl chains, the high steric hindrance also enhances the dispersion effect of the superplasticizer in concrete, improving the workability and fluidity of the concrete. In the later stages of cement hydration in the concrete, SO₂ will also slowly ionize. 3- Ions continuously provide electrostatic repulsion to compensate for slump loss. Simultaneously, this air-entraining monomer interacts with Ca in the concrete. 2+ The binding ability is far lower than that of COO. - The presence of ions prevents the formation of dense precipitates, thus ensuring the homogeneity and stability of the water-reducing agent system. Furthermore, the preparation of this gas-entraining monomer is carried out at a relatively low temperature of 55-65°C in an aqueous phase. The dodecyl sulfonic acid or dodecylbenzene sulfonic acid micelles coating glycidyl methacrylate inhibits homopolymerization, significantly increasing the retention rate of double bonds and improving the purity of the gas-entraining monomer product.

[0060] 3. This invention provides an anti-mud polycarboxylate superplasticizer, comprising an anti-mud monomer prepared from an unsaturated ester monomer and phosphorus pentoxide. The phosphate ions in this anti-mud monomer have a stronger adsorption effect on concrete particles, and can continuously hydrolyze during the cement hydration process in concrete, continuing to release phosphate ions, thus slowing down the cement hydration rate in concrete, improving dispersion, and, combined with an air-entraining monomer, can simultaneously enhance the anti-mud and slump-retaining effects of the superplasticizer. Furthermore, this anti-mud monomer also possesses carboxylic acid groups, which can provide better water-reducing effects.

[0061] 4. The preparation method of the anti-mud polycarboxylate superplasticizer provided by the present invention includes the following steps: Step S31: Mixing unsaturated polyether monomer, oxidant, chain transfer agent and water to obtain a base material; Step S32: Mixing unsaturated carboxylate monomer, anti-mud monomer and air-entraining monomer to obtain liquid A; Step S33: Mixing reducing agent and water to obtain liquid B; Step S34: Adding liquid A and liquid B dropwise to the base material and maintaining the temperature for reaction to obtain the anti-mud polycarboxylate superplasticizer. This method has a simple process, and the product has better water-reducing effect and slump retention performance, and has broad application value. Detailed Implementation

[0062] The following embodiments are provided to better understand the present invention and are not limited to the preferred embodiments described. They do not constitute a limitation on the content and scope of protection of the present invention. Any product that is the same as or similar to the present invention, derived by any person under the guidance of the present invention or by combining the features of the present invention with other prior art, falls within the protection scope of the present invention.

[0063] For experiments not specifically described in the examples, the procedures or conditions should be followed according to the conventional experimental procedures described in the literature in this field. Reagents or instruments whose manufacturers are not specified are all commercially available conventional reagent products.

[0064] Example 1

[0065] Preparation of anti-mud monomer A1: 200g of phosphorus pentoxide was added to a four-necked flask, along with 100g of 1,2-dichloromethane, and stirred thoroughly to obtain a first mixture. Under nitrogen protection, 480g of hydroxyethyl acrylate was slowly added dropwise to the first mixture, maintaining the temperature at 60℃ and stirring for 90min. After the addition was complete, the reaction was continued at 60℃ for 1h, and then the solvent was evaporated by rotary evaporation to obtain anti-mud monomer A1.

[0066] Preparation of anti-mud monomer A2: 200g of phosphorus pentoxide was added to a four-necked flask, along with 100g of acetonitrile, and the mixture was stirred thoroughly to obtain a first mixture. Under nitrogen protection, 500g of hydroxyethyl acrylate was slowly added dropwise to the first mixture, with the temperature controlled at 65℃ and the mixture stirred for 90min. After the addition was complete, the reaction was continued at 65℃ for 1h, and then the solvent was evaporated by rotary evaporation to obtain anti-mud monomer A2.

[0067] Preparation of anti-mud monomer A3: 200g of phosphorus pentoxide was added to a four-necked flask, along with 100g of 1,2-dichloroethane, and stirred thoroughly to obtain a first mixture. Under nitrogen protection, 520g of hydroxypropyl acrylate was slowly added dropwise to the first mixture, maintaining the temperature at 70℃, and stirred for 100min. After the addition was complete, the reaction was continued at 70℃ for 1h, and then the solvent was evaporated by rotary evaporation to obtain anti-mud monomer A3.

[0068] Example 2

[0069] Preparation of gas-entraining monomer B1: 10g of dodecyl sulfonic acid was added to a three-necked flask and mixed with 100g of acetone / water (volume ratio 1:1) to obtain solution A; 0.5g of phase transfer catalyst tetrabutylammonium bromide was added to solution A, and the temperature was raised to 60℃. 4ml of glycidyl methacrylate was added dropwise to the three-necked flask over a period of 1.5h, with stirring maintained during the addition and the temperature controlled at 60℃. After the addition was complete, stirring was continued at 60℃ for 6h. After the reaction was complete, the final product was extracted with ethyl acetate solvent. The extract was washed with saturated saline solution and dried under vacuum to obtain gas-entraining monomer B1.

[0070] Preparation of gas-entraining monomer B2: 10 g of dodecylbenzenesulfonic acid was added to a three-necked flask and mixed with 100 g of acetone / water (volume ratio 1:1) to obtain solution A. 0.5 g of phase-transfer catalyst tetrabutylammonium bisulfate was added to solution A, and the temperature was raised to 55 °C. 6 ml of glycidyl methacrylate was then added dropwise to the three-necked flask over 1.5 h, with stirring maintained during the addition and the temperature controlled at 65 °C. After the addition was complete, stirring continued for 8 h. After the reaction was complete, the final product was extracted with ethyl acetate. The extract was washed with saturated saline solution and dried under vacuum to obtain gas-entraining monomer B2.

[0071] Example 3

[0072] This embodiment provides a mud-resistant polycarboxylate superplasticizer, comprising the following raw materials:

[0073] 100g of vinyl polyethylene glycol ether with a number average molecular weight of 1200, 0.01g of ferrous sulfate, 5g of sodium hypophosphite, 10g of hydrogen peroxide, 5g of acrylic acid, 5g of anti-mud monomer A1 (provided in Example 1), 2g of air-entraining monomer B1 (provided in Example 2), 0.4g of sodium dioctyl succinate sulfonate (E51) and 250g of water.

[0074] This embodiment provides a method for preparing an anti-mud-type polycarboxylate superplasticizer, including the following steps:

[0075] (1) Place vinyl polyethylene glycol ether and 100g of water in a four-necked flask, stir to dissolve, then add ferrous sulfate, sodium hypophosphite and hydrogen peroxide to obtain the base material;

[0076] (2) Mix acrylic acid, anti-mud monomer A1, air-entraining monomer B1 with 50g of water to obtain solution A;

[0077] (3) Mix E51 with 100g of water to obtain solution B;

[0078] (4) Adjust the reaction temperature to 50℃, and add solutions A and B dropwise to the four-necked flask at the same time. The dropwise addition time of solution A is 120 min and the dropwise addition time of solution B is 140 min. After the dropwise addition is completed, keep the temperature at 50℃ for 60 min. Then add a 32% sodium hydroxide solution to neutralize the mixture until the pH is 4, and the anti-mud polycarboxylate superplasticizer is obtained.

[0079] Example 4

[0080] This embodiment provides a mud-resistant polycarboxylate superplasticizer, comprising the following raw materials:

[0081] 100g of vinyl polyethylene glycol ether with a molecular weight of 2400, 0.01g of ferrous sulfate, 5g of sodium hypophosphite, 10g of hydrogen peroxide, 5g of acrylic acid, 5g of anti-mud monomer A2 (provided in Example 1), 2g of air-entraining monomer B2 (provided in Example 2), 0.4g of E51 and 250g of water.

[0082] This embodiment provides a method for preparing an anti-mud-type polycarboxylate superplasticizer, including the following steps:

[0083] (1) Place vinyl polyethylene glycol ether and 100g of water in a four-necked flask, stir to dissolve, then add ferrous sulfate, sodium hypophosphite and hydrogen peroxide to obtain the base material;

[0084] (2) Mix acrylic acid, anti-mud monomer A2, air-entraining monomer B2 with 50g of water to obtain solution A;

[0085] (3) Mix E51 with 100g of water to obtain solution B;

[0086] (4) Adjust the reaction temperature to 60℃, and add solutions A and B dropwise to the four-necked flask at the same time. The dropwise addition time of solution A is 140 min and the dropwise addition time of solution B is 160 min. After the dropwise addition is completed, keep the temperature at 60℃ for 60 min. Then add a 32% sodium hydroxide solution to neutralize the mixture until the pH is 4, and the anti-mud polycarboxylate superplasticizer is obtained.

[0087] Example 5

[0088] This embodiment provides a mud-resistant polycarboxylate superplasticizer, comprising the following raw materials:

[0089] 100g of isopentenyl alcohol polyoxyethylene ether with a number average molecular weight of 1200, 0.01g of ferrous sulfate, 5g of sodium hypophosphite, 10g of hydrogen peroxide, 5g of acrylic acid, 5g of anti-mud monomer A3 (provided in Example 1), 2g of air-entraining monomer B2 (provided in Example 2), 0.4g of E51 and 250g of water.

[0090] This embodiment provides a method for preparing an anti-mud-type polycarboxylate superplasticizer, including the following steps:

[0091] (1) Place isopentenyl alcohol polyoxyethylene ether and 100g of water in a four-necked flask, stir to dissolve, and then add ferrous sulfate, sodium hypophosphite and hydrogen peroxide to obtain the base material.

[0092] (2) Mix acrylic acid, anti-mud monomer A3, air-entraining monomer B2 with 50g of water to obtain solution A;

[0093] (3) Mix E51 with 100g of water to obtain solution B;

[0094] (4) Adjust the reaction temperature to 65℃, and add solutions A and B dropwise to the four-necked flask at the same time. The dropwise addition time of solution A is 160 min and the dropwise addition time of solution B is 160 min. After the dropwise addition is completed, keep the temperature at 65℃ for 60 min. Then add a 32% sodium hydroxide solution to neutralize the mixture until the pH is 4, and the anti-mud polycarboxylate superplasticizer is obtained.

[0095] Example 6

[0096] This embodiment provides a mud-resistant polycarboxylate superplasticizer, comprising the following raw materials:

[0097] 100g of isopentenyl alcohol polyoxyethylene ether with a number average molecular weight of 1500, 0.01g of ferrous sulfate, 5g of thioglycolic acid, 10g of ammonium persulfate, 5g of methacrylic acid, 5g of anti-mud monomer A3 (provided in Example 1), 2g of air-entraining monomer B2 (provided in Example 2), 0.4g of sodium sulfite and 250g of water.

[0098] This embodiment provides a method for preparing an anti-mud-type polycarboxylate superplasticizer, including the following steps:

[0099] (1) Place isopentenyl alcohol polyoxyethylene ether and 100g of water in a four-necked flask, stir to dissolve, and then add ferrous sulfate, thioglycolic acid and ammonium persulfate to obtain the base material.

[0100] (2) Mix methacrylic acid, anti-mud monomer A3, air-entraining monomer B2 with 50g of water to obtain solution A;

[0101] (3) Mix sodium sulfite with 100g of water to obtain solution B;

[0102] (4) Adjust the reaction temperature to 70℃, and add A and B solutions dropwise to the four-necked flask at the same time. The dropwise addition time of A solution is 160 min and the dropwise addition time of B solution is 160 min. After the dropwise addition is completed, keep the temperature at 70℃ for 60 min. Then add a 30% sodium hydroxide solution to neutralize the mixture until the pH is 4, and the anti-mud polycarboxylate superplasticizer is obtained.

[0103] Example 7

[0104] This embodiment provides a mud-resistant polycarboxylate superplasticizer, comprising the following raw materials:

[0105] 100g of isopentenyl alcohol polyoxyethylene ether with a number average molecular weight of 3000, 0.01g of ferrous sulfate, 5g of mercaptoacetic acid, 10g of sodium dichromate, 5g of maleic anhydride, 5g of anti-mud monomer A1 (provided in Example 1), 2g of air-entraining monomer B2 (provided in Example 2), 0.4g of ascorbic acid and 250g of water.

[0106] This embodiment provides a method for preparing an anti-mud-type polycarboxylate superplasticizer, including the following steps:

[0107] (1) Place isopentenyl alcohol polyoxyethylene ether and 100g of water in a four-necked flask, stir to dissolve, and then add ferrous sulfate, mercaptoacetic acid and sodium dichromate to obtain the base material.

[0108] (2) Mix maleic anhydride, anti-mud monomer A1, air-entraining monomer B2 with 50g of water to obtain solution A;

[0109] (3) Mix ascorbic acid with 100g of water to obtain solution B;

[0110] (4) Adjust the reaction temperature to 70℃, and add A and B solutions dropwise to the four-necked flask at the same time. The dropwise addition time of A solution is 160 min and the dropwise addition time of B solution is 160 min. After the dropwise addition is completed, keep the temperature at 70℃ for 60 min. Then add a 30% sodium hydroxide solution to neutralize the mixture until the pH is 4, and the anti-mud polycarboxylate superplasticizer is obtained.

[0111] Comparative Example 1

[0112] The difference from Example 3 is that no anti-mud monomer is added, and the amount of water is adjusted so that the total amount of each raw material of the anti-mud polycarboxylate superplasticizer remains unchanged. The other steps are the same as in Example 3.

[0113] Comparative Example 2

[0114] The difference from Example 3 is that no air-entraining monomer is added, and the amount of water is adjusted so that the total amount of each raw material of the anti-mud polycarboxylate superplasticizer remains unchanged. The other steps are the same as in Example 3.

[0115] Comparative Example 3

[0116] The difference from Example 3 is that the anti-mud monomer and air-entraining monomer are not added, and the amount of water is adjusted so that the total amount of each raw material of the anti-mud polycarboxylate superplasticizer remains unchanged. The other steps are the same as in Example 3.

[0117] Comparative Example 4

[0118] By replacing the dodecyl sulfonic acid in the preparation of air-entraining monomer B1 in Example 2 with an equimolar amount of citric acid, and keeping all other steps unchanged, air-entraining monomer B3 was prepared.

[0119] By replacing the air-entraining monomer B1 in Example 3 with the same mass of air-entraining monomer B3, and keeping other steps unchanged, an anti-mud polycarboxylate superplasticizer was prepared.

[0120] Comparative Example 5

[0121] By replacing hydroxyethyl acrylate in the preparation of anti-mud monomer A1 in Example 1 with an equimolar amount of monoethyl maleate, while keeping other steps unchanged, anti-mud monomer A4 was prepared.

[0122] By replacing the anti-mud monomer A1 in Example 3 with the same mass of the anti-mud monomer A4, and keeping other steps unchanged, an anti-mud polycarboxylate superplasticizer was prepared.

[0123] Experimental Example 1

[0124] The anti-mud polycarboxylate superplasticizers prepared in Examples 3-5 and Comparative Examples 1-5, as well as commercially available products (anti-mud polycarboxylate superplasticizers, purchased from Jiangsu Subote New Material Co., Ltd., item number: SBT808), were applied to C30 concrete with a mud content of 5% in manufactured sand. The concrete mix proportions are shown in Table 1.

[0125] Table 1 Concrete Mix Proportions

[0126] Material cement fly ash Mineral powder Manufactured sand pebbles water Dosage / Kg 280 40 40 770 1045 160

[0127] The cement used in the concrete preparation was purchased from Ningbo Conch Cement Co., Ltd., the fly ash and mineral powder were purchased from Ningbo Yinzhou Tuotou Fly Ash Co., Ltd., and the manufactured sand and gravel were purchased from Ningbo Yinzhou Nanyang Manufactured Sand Co., Ltd.

[0128] The spread and 60-minute spread of the concrete obtained above were determined according to GB 8076-2008 "Concrete Admixtures", and the air void time of the concrete was determined according to GB / T50080-2016 "Standard for Test Methods of Performance of Ordinary Concrete Mixtures". The results are shown in Table 2.

[0129] Table 2 Experimental Results

[0130]

[0131]

[0132] As shown in Table 2, the water-reducing agents prepared using Examples 3-7 of this invention have low dosages in concrete, and the resulting concrete exhibits lower spread and air-filling time. This indicates that the water-reducing agent provided by this invention has better dispersibility and anti-mud effect at lower dosages. In contrast, the water-reducing agent in Comparative Example 1, which did not contain an anti-mud monomer, showed reduced concrete fluidity and increased air-filling time even with increased dosage compared to Example 3. This demonstrates that the introduction of the anti-mud monomer in this invention improves the dispersibility of the concrete paste. Similarly, the water-reducing agent in Comparative Example 2, which did not contain an air-entraining monomer, showed reduced concrete fluidity and increased air-filling time even with increased dosage compared to Example 3. This indicates that the introduction of the air-entraining monomer effectively improves the dispersibility of the concrete. Furthermore, the water-reducing agent in Comparative Example 3, which did not contain either an anti-mud monomer or an air-entraining monomer, showed reduced concrete fluidity and significantly increased air-filling time, indicating poor dispersibility, even with increased dosage compared to Example 3. Combined with the results of Comparative Examples 1-3, this demonstrates that the introduction of the anti-mud monomer and air-entraining monomer effectively improves the workability and flow rate of concrete. In contrast, the anti-mud monomers and air-entraining monomers prepared using different raw materials in Comparative Examples 4 and 5 resulted in water-reducing agents with poorer fluidity and air-entraining time in concrete compared to the examples, further demonstrating that the water-reducing agent provided by the present invention has significant advantages.

[0133] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A mud-resistant polycarboxylate superplasticizer, characterized in that, By weight, it includes the following raw materials: 100-180 parts of unsaturated polyether monomer, 5-10 parts of unsaturated carboxylic acid monomer, 2-5 parts of air-entraining monomer, 5-10 parts of anti-mud monomer, 10-20 parts of oxidant, 0.4-0.6 parts of reducing agent, 5-7 parts of chain transfer agent and 150-300 parts of water; The air-entraining unit has the structure shown in Formula I or Formula II: Formula I, Formula II; The anti-mud monomer has the structure shown in Formula III: Formula III, in: n is an integer selected from 1 to 3; R is independently selected from any of the following groups: 。 2. The anti-mud polycarboxylate superplasticizer according to claim 1, characterized in that, The raw materials for preparing the gas-entraining monomer include raw material A and glycidyl methacrylate; raw material A is selected from dodecyl sulfonic acid or dodecylbenzene sulfonic acid.

3. The anti-mud polycarboxylate superplasticizer according to claim 2, characterized in that, The preparation method of the air-entraining monomer includes the following steps: Step S11: Dissolve raw material A in a solvent to obtain solution A; Step S12: Add a phase transfer catalyst to solution A to obtain solution B; Step S13: Glycidyl methacrylate is added to solution B and mixed, then heated to react and obtain the gas-entraining monomer.

4. The anti-mud polycarboxylate superplasticizer according to claim 3, characterized in that, The mass ratio of raw material A to glycidyl methacrylate is 1-3 g: 1 mL; And / or, the mass ratio of the phase transfer catalyst to raw material A is 1:20; And / or, the mass ratio of raw material A to solvent is 1:5-15; And / or, in step S11, the solvent is selected from acetone and water, with a volume ratio of acetone to water of 0.5-1:1; And / or, in step S12, the phase transfer catalyst includes at least one of benzyltriethylammonium chloride, tetrabutylammonium bromide, tetrabutylammonium hydrogen sulfate, and hexadecyltrimethylammonium bromide; And / or, in step S13, glycidyl methacrylate is added to solution B by dropping, with stirring maintained during the dropping process, the dropping time is 7-8 hours, the temperature of solution B is controlled at 55-65℃, and after the dropping is completed, the reaction is continued to be heated and stirred at 55-65℃ for 2-3 hours. And / or, in step S13, after the reaction is completed, the steps of adjusting the pH of the reaction solution to 2-3, extraction, washing and drying are also included.

5. The anti-mud polycarboxylate superplasticizer according to claim 3, characterized in that, In step S12, the phase transfer catalyst includes tetrabutylammonium bromide.

6. The anti-mud polycarboxylate superplasticizer according to claim 4, characterized in that, The extraction solvent is selected from at least one of ethyl acetate, butyl acetate, and amyl acetate; And / or, the washing operation is performed by washing with at least one of saturated saline solution, ethanol, and water.

7. The anti-mud polycarboxylate superplasticizer according to claim 1, characterized in that, The preparation method of the anti-mud monomer includes the following steps: Step S21: Phosphorus pentoxide is mixed with an organic solvent to obtain a first mixture; Step S22: Add unsaturated ester monomers to the first mixture and allow it to react at a controlled temperature to obtain the anti-mud monomer.

8. The anti-mud polycarboxylate superplasticizer according to claim 7, characterized in that, The mass ratio of phosphorus pentoxide to organic solvent is 1:0.5-1; And / or, the mass ratio of phosphorus pentoxide to unsaturated ester monomer is 1:2-3.

9. The anti-mud polycarboxylate superplasticizer according to claim 7, characterized in that, In step S21, the organic solvent is selected from at least one of diethyl ether, dichloromethane, 1,2-dichloroethane, acetonitrile, and N,N-dimethylformamide; And / or, in step S22, the unsaturated ester monomer is selected from at least one of hydroxyethyl acrylate, hydroxypropyl acrylate, and hydroxybutyl acrylate; And / or, in step S22, the unsaturated ester monomer is added to the first mixture dropwise for 90-120 minutes, the temperature of the first mixture is controlled at 60-70°C, and the reaction is continued at 60-70°C for 1-2 hours after the dropwise addition is completed.

10. The anti-mud polycarboxylate superplasticizer according to claim 7, characterized in that, In step S21, the organic solvent is selected from at least one of dichloromethane, 1,2-dichloroethane, and acetonitrile.

11. The anti-mud polycarboxylate superplasticizer according to claim 1, characterized in that, The unsaturated polyether monomer is selected from at least one of vinyl polyethylene glycol ether and isopentenyl alcohol polyoxyethylene ether; And / or, the unsaturated carboxylic acid monomer is selected from at least one of acrylic acid, methacrylic acid, and maleic anhydride; And / or, the oxidant is selected from at least one of hydrogen peroxide, sodium peroxide, sodium persulfate, ammonium persulfate, sodium dichromate, potassium dichromate, and potassium permanganate; And / or, the reducing agent is selected from at least one of sodium dioctyl succinate sulfonate, ascorbic acid, sodium formaldehyde sulfoxylate, sodium sulfite, sodium bisulfite, and sodium hypophosphite; And / or, the chain transfer agent is at least one of thioglycolic acid, sodium hypophosphite, trisodium phosphate, mercaptopropionic acid, and mercaptoethanol; And / or, it also includes 0.01-0.02 parts by weight of a catalyst, said catalyst being ferrous sulfate.

12. The anti-mud polycarboxylate superplasticizer according to claim 11, characterized in that, The number average molecular weight of the vinyl polyethylene glycol ether or isopentenyl alcohol polyoxyethylene ether is 1000-3000.

13. The method for preparing the anti-mud-type polycarboxylate superplasticizer according to any one of claims 1-12, characterized in that, Includes the following steps: Step S31: Mix unsaturated polyether monomers, oxidants, chain transfer agents and water to obtain the base material; Step S32: Mix unsaturated carboxylic acid monomer, anti-mud monomer, air-entraining monomer with water to obtain solution A; Step S33: Mix the reducing agent with water to obtain solution B; Step S34: Add liquid A and liquid B to the base material, keep it warm and react to obtain the anti-mud polycarboxylate superplasticizer.

14. The preparation method of the anti-mud type polycarboxylate superplasticizer according to claim 13, characterized in that, In step S31, the mass ratio of unsaturated polyether monomer to water is 1:1.5-3. And / or, in step S32, the mass ratio of unsaturated carboxylic acid monomer to water is 1:5-10; And / or, in step S33, the mass ratio of reducing agent to water is 0.4:80-120; And / or, step S31 may further include the step of adding a catalyst; And / or, in step S34, the droplet addition time of liquid A is 120-160 min, and the droplet addition temperature is 50-70℃; the droplet addition time of liquid B is 140-160 min, and the droplet addition temperature is 50-70℃. After the droplet addition is completed, the reaction is continued at 60-70℃ for 0.5-1.5 h.

15. A type of concrete, characterized in that, This includes the anti-mud polycarboxylate superplasticizer according to any one of claims 1-12 or the anti-mud polycarboxylate superplasticizer prepared by the preparation method according to claim 13 or 14.

16. The concrete according to claim 15, characterized in that, The amount of the anti-mud polycarboxylate superplasticizer added is 1.5-2% of the concrete mass.

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