Sulfate-erosion-resistant polycarboxylate superplasticizer as well as preparation method and application thereof

Abstract

The invention relates to a sulfate-erosion-resistant polycarboxylate superplasticizer and a preparation method and application thereof, and the sulfate-erosion-resistant polycarboxylate superplasticizer is prepared from the following raw materials in parts by weight: 200-300 parts of unsaturated polyether macromonomer, 10-30 parts of polycarboxylate superplasticizer, 10-30 parts of polycarboxylate superplasticizer, 10-30 parts of polycarboxylate superplasticizer, 10-30 parts of polycarboxylate superplasticizer, 10-30 parts of polycarboxylate superplasticizer, 10-30 parts of polycarboxylate superplasticizer, 10-30 parts 15 to 20 parts of an unsaturated'beta-cyclodextrin-graphene oxide 'supramolecular hybrid body; 3-7 parts of an oxidant; 0.1 to 1.0 part of a reducing agent; 0.5 to 3.0 parts of a chain transfer agent; 15 to 20 parts of unsaturated acid; and 5 to 10 parts of octylphenol polyoxyethylene ether acrylate. The unsaturated'beta-cyclodextrin-graphene oxide 'supramolecular hybrid and the alkylphenol polyoxyethylene ether acrylate are introduced into the sulfate erosion resistant polycarboxylate superplasticizer, so that the technical problem of alkali aggregate reaction of preservatives in the prior art is solved.

Description

Technical Field

[0001] The invention relates to the technical field of concrete admixtures, in particular to a sulfate-resistant polycarboxylate water-reducing agent and a preparation method and application thereof. Background Art

[0002] With the increasing attention paid to the durability of concrete, sulfate attack has become one of the important reasons affecting the non-mechanical damage of concrete. Sulfate is widely present in the ocean, salt lakes and groundwater, which corrodes concrete and shortens its service life. The internal causes of sulfate attack include hydrated calcium aluminate, calcium hydroxide and capillary pores in cement stone, and the external causes are sulfate ions (SO4 2- ).

[0003] The prior art has disclosed a variety of anti-sulfate corrosion agents, such as the concrete anti-sulfate corrosion agent in patent CN201019006013.9 and the liquid preservative in patent CN117886543A. Although they have certain anti-corrosion effects, they have the hidden danger of alkali-aggregate reaction and the formula is complicated. Summary of the invention

[0004] Based on this, it is necessary to provide a water reducing agent with strong durability and excellent resistance to sulfate erosion to solve the problem of alkali-aggregate reaction in the prior art.

[0005] To achieve the above object, the present invention provides a technical solution:

[0006] A sulfate-resistant polycarboxylate water-reducing agent, wherein the raw materials for preparing the sulfate-resistant polycarboxylate water-reducing agent include, by weight:

[0007]

[0008] Furthermore, the raw materials for preparing the unsaturated "β-cyclodextrin-graphene oxide" supramolecular hybrid include: β-cyclodextrin, alkali, acryloyl chloride, graphene oxide and water.

[0009] Furthermore, the preparation steps of the unsaturated "β-cyclodextrin-graphene oxide" supramolecular hybrid include:

[0010] S101, uniformly mixing β-cyclodextrin, alkali and water to obtain an alkaline solution; specifically, this step is to fully dissolve β-cyclodextrin in an alkaline environment to provide active groups for subsequent reactions.

[0011] S102. Add acryloyl chloride to the alkaline solution through a constant pressure funnel, and obtain unsaturated β-cyclodextrin after modification with acryloyl chloride; specifically, the purpose of this step is to unsaturate β-cyclodextrin by introducing acryloyl chloride to form acryloyl-modified unsaturated β-cyclodextrin. More specifically, since acryloyl chloride has a high reaction activity, and the reaction of acryloyl chloride and β-cyclodextrin is an exothermic reaction, excessively high temperature during the reaction will accelerate the decomposition of acryloyl chloride and reduce the yield of the product. Therefore, the reaction temperature cannot be too high, and the reaction temperature needs to be controlled within the range of 0 to 5°C. More specifically, the unsaturated β-cyclodextrin obtained in this step can be purified, and the specific steps of the purification treatment are as follows:

[0012] After filtering the solution, the unsaturated β-cyclodextrin was dissolved in N,N-dimethylformamide and filtered to remove the sodium chloride;

[0013] Acetone is added to the filtrate, and the precipitate is collected and dissolved in methanol. Subsequently, acetone is added to collect the precipitate, and the precipitate is dried under reduced pressure to obtain purified unsaturated β-cyclodextrin.

[0014] S103, subjecting the unsaturated β-cyclodextrin and graphene oxide to ultrasonic treatment to obtain the unsaturated "β-cyclodextrin-graphene oxide" supramolecular hybrid. Specifically, this step promotes the combination of unsaturated β-cyclodextrin and graphene oxide through ultrasonic treatment to form an unsaturated β-cyclodextrin covalently modified graphene oxide hybrid material.

[0015] Furthermore, the molar ratio of the β-cyclodextrin to the base is (7.0-8.5):(0.1-0.25).

[0016] Furthermore, the unsaturated polyether macromonomer includes at least one of ethoxy vinyl polyethylene glycol ether, isopentenyl polyethylene glycol ether and isobutylene alcohol polyoxyethylene ether, and has a molecular weight of 2000 to 3500.

[0017] Furthermore, the oxidant includes at least one of peracetic acid, hydrogen peroxide and ammonium persulfate.

[0018] Further, the reducing agent includes at least one of L-ascorbic acid-2-phosphate sodium salt, 5,6-isopropylidene-L-ascorbic acid and sodium D-isoascorbate.

[0019] Further, the chain transfer agent includes at least one of 4-mercaptophenylacetic acid, 2-(ethylthio)acetic acid and 4-mercaptophenylacetic acid.

[0020] The present invention also provides a method for preparing a sulfate-resistant polycarboxylate water-reducing agent, comprising the steps of:

[0021] The unsaturated polyether macromonomer, unsaturated "β-cyclodextrin-graphene oxide" supramolecular hybrid, oxidant, reductant, chain transfer agent, unsaturated acid and octylphenol polyoxyethylene ether acrylate are mixed and reacted to obtain the sulfate-resistant polycarboxylic acid water-reducing agent.

[0022] The invention also provides application of a sulfate-resistant polycarboxylate water-reducing agent in concrete.

[0023] Beneficial effects of the present invention:

[0024] 1. The sulfate-resistant polycarboxylate water-reducing agent provided by the present invention contains a surface hydrophobic monomer octylphenol polyoxyethylene ether acrylate, which can form a hydrophobic isolation layer on the surface of concrete to prevent sulfate from entering the concrete and prevent sulfate-corrosion media from entering the interior of the concrete and causing damage to the concrete structure.

[0025] 2. The sulfate-resistant polycarboxylate water-reducing agent provided by the present invention introduces an unsaturated "β-cyclodextrin-graphene oxide" supramolecular hybrid, wherein the β-cyclodextrin has an excellent "internal hydrophobic" effect, which can reduce the pores and micropores formed in the later stage of concrete curing, and improve the density of the concrete. The graphene oxide in the molecular structure makes the cement hydrate more fully, reduces the porosity and pore size, and reduces the sulfate-corrosion medium from entering the interior of the concrete through the combination of internal and external blocking, thereby reducing the damage of the sulfate-corrosion medium to the durability of the concrete.

[0026] 3. The sulfate-resistant polycarboxylate water-reducing agent provided by the present invention contains graphene oxide in the unsaturated "β-cyclodextrin-graphene oxide" supramolecular hybrid structure. When added to concrete, a large number of flaky crystals appear in the concrete, and the hydration products are stacked on top of each other, with sharp edges, a dense structure and fewer free hydration products. The coarse aggregate and the slurry are bonded as a whole, the crack barrier is significantly reduced, and the hydration products are closely attached around the aggregate. The presence of graphene oxide further strengthens the bonding effect between the coarse aggregate and the cement slurry, further improves the density of the concrete, and reduces the entry of external sulfate solution. DETAILED DESCRIPTION

[0027] In order to better illustrate the purpose, technical solutions and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments.

[0028] In the examples, the test methods used are conventional methods unless otherwise specified, and the materials, reagents, etc. used are all commercially available unless otherwise specified.

[0029] Example 1

[0030] Embodiment 1 of the present invention provides a sulfate-resistant polycarboxylate water-reducing agent, which is prepared by the following steps:

[0031] S100, preparation of unsaturated "β-cyclodextrin-graphene oxide" supramolecular hybrid:

[0032] S101, weigh β-cyclodextrin and NaOH in a molar ratio of 7.0:0.15, add them into a 500 mL round-bottom flask, add 250 mL of distilled water, and after the solid is dissolved, obtain an alkaline solution;

[0033] S102, placing the flask in an ice water bath (1.5°C), adding 15 mL of acryloyl chloride into the flask using a constant pressure funnel, and stirring for 30 minutes to obtain unsaturated β-cyclodextrin;

[0034] Purification process of unsaturated β-cyclodextrin:

[0035] After filtering the solution, it was dried under reduced pressure at 40°C, and then the crude product was dissolved in 20 mL of N,N-dimethylformamide and filtered to remove the sodium chloride;

[0036] 200 mL of acetone was added to the filtrate, and the precipitate was collected and dissolved in 20 ml of methanol. Subsequently, 200 mL of acetone was added, and the precipitate was collected and dried under reduced pressure at 40° C. for 5 hours to obtain purified unsaturated β-cyclodextrin.

[0037] S103, ultrasonically treating the unsaturated β-cyclodextrin and graphene oxide in water for 2 hours, and preparing unsaturated β-cyclodextrin covalently modified graphene oxide after vacuum drying, wherein the product is an unsaturated "β-cyclodextrin-graphene oxide" supramolecular hybrid.

[0038] Preparation of S200 and A solution:

[0039] 0.25 parts of sodium D-isoascorbate and 0.8 parts of 2-(ethylthio)acetic acid were dissolved in deionized water and mixed and stirred to obtain a liquid A with a mass fraction of 8.5%.

[0040] Preparation of S300 and B solution:

[0041] 15 parts of acrylic acid and 5 parts of octylphenol polyoxyethylene ether acrylate were mixed and stirred evenly with deionized water to prepare a liquid B with a mass fraction of 25%.

[0042] Preparation of S400, sulfate-resistant polycarboxylate water reducer:

[0043] At 15° C., 250 parts of ethoxy vinyl polyethylene glycol ether and 15 parts of unsaturated “β-cyclodextrin-graphene oxide supramolecular hybrid” were mixed and stirred uniformly with deionized water;

[0044] Then add 4 parts of ammonium persulfate and stir evenly to obtain a mixed solution with a mass fraction of 60%;

[0045] The A solution was dripped into the mixed solution at a uniform speed for 60 minutes;

[0046] After adding the A solution for 5 minutes, add the B solution at a uniform speed for 75 minutes;

[0047] After the addition is completed, keep warm for 30 minutes;

[0048] After the heat preservation reaction is completed, a sodium hydroxide solution with a mass fraction of 32% is added dropwise to adjust the pH to 5.5 to obtain the sulfate-resistant polycarboxylate water-reducing agent.

[0049] Example 2

[0050] Embodiment 2 of the present invention provides a sulfate-resistant polycarboxylate water-reducing agent, which is prepared by the following steps:

[0051] S100, preparation of unsaturated "β-cyclodextrin-graphene oxide supramolecular hybrid":

[0052] S101. Weigh β-cyclodextrin and NaOH in a molar ratio of 7.5:0.2, add them into a 500 mL round-bottom flask, and add 250 mL of distilled water. After the solid is dissolved, an alkaline solution is obtained;

[0053] S102, placing the flask in an ice water bath (1.5°C), adding 13 mL of acryloyl chloride into the flask containing the alkaline solution using a constant pressure funnel, and stirring for 30 minutes to obtain acryloyl-modified unsaturated β-cyclodextrin;

[0054] Purification process of unsaturated β-cyclodextrin:

[0055] After filtering the solution, it was dried under reduced pressure at 40 °C, and then the crude product was dissolved in 15 mL of N, N-dimethylformamide and filtered to remove the sodium chloride;

[0056] 200 mL of acetone was added to the filtrate, and the precipitate was collected and dissolved in 20 mL of methanol. Then 200 mL of acetone was added to collect the precipitate, and the precipitate was dried under reduced pressure at 40° C. for 5 hours to obtain unsaturated β-cyclodextrin.

[0057] S103. Unsaturated β-cyclodextrin and graphene oxide are ultrasonically treated in water for 2 hours, and then vacuum dried to obtain unsaturated β-cyclodextrin covalently modified graphene oxide, and the product is an unsaturated "β-cyclodextrin-graphene oxide" supramolecular hybrid.

[0058] Preparation of S200 and A solution

[0059] 0.3 parts of sodium D-isoascorbate and 0.6 parts of 4-mercaptophenylacetic acid were mixed and stirred evenly with deionized water to prepare a liquid A with a mass fraction of 8.0%.

[0060] Preparation of S300 and B solution

[0061] 17 parts of acrylic acid and 8 parts of octylphenol polyoxyethylene ether acrylate were mixed and stirred evenly with deionized water to prepare a liquid B with a mass fraction of 23%.

[0062] Preparation of S400, sulfate-resistant polycarboxylate water reducer

[0063] At 15° C., 280 parts of ethoxy vinyl polyethylene glycol ether and 17-unsaturated “β-cyclodextrin-graphene oxide supramolecular hybrid” were mixed and stirred uniformly with deionized water;

[0064] Then add 5 parts of hydrogen peroxide and stir evenly to obtain a mixed solution with a mass fraction of 60%;

[0065] The A solution was dripped into the mixed solution at a uniform speed for 60 minutes;

[0066] After adding the A solution for 5 minutes, add the B solution at a uniform speed for 75 minutes;

[0067] After the addition is completed, keep warm for 30 minutes;

[0068] After the heat preservation reaction is completed, a sodium hydroxide solution with a mass fraction of 32% is added dropwise to adjust the pH to 5.2 to obtain the sulfate-resistant polycarboxylate water-reducing agent.

[0069] Example 3

[0070] Embodiment 3 of the present invention provides a sulfate-resistant polycarboxylate water-reducing agent, which is prepared by the following steps:

[0071] S100, preparation of unsaturated "β-cyclodextrin-graphene oxide supramolecular hybrid":

[0072] S101, weigh β-cyclodextrin and NaOH in a molar ratio of 7.5:0.15, add them into a 500 mL round-bottom flask, and add 250 mL of distilled water, after the solid is dissolved, obtain an alkaline solution;

[0073] S102, placing the flask in an ice water bath (1.5° C.), adding 15 mL of acryloyl chloride into the flask using a constant pressure funnel, and stirring for 30 minutes to obtain acryloyl-modified unsaturated β-cyclodextrin;

[0074] Purification process of unsaturated β-cyclodextrin:

[0075] After filtering the solution, it was dried under reduced pressure at 40°C, and then the crude product was dissolved in 20 mL of N,N-dimethylformamide and filtered to remove the sodium chloride;

[0076] 200 mL of acetone was added to the filtrate, and the precipitate was collected and dissolved in 20 mL of methanol. Then 200 mL of acetone was added to collect the precipitate, and the precipitate was dried under reduced pressure at 40°C for 5 hours to obtain unsaturated β-cyclodextrin.

[0077] S103. Unsaturated β-cyclodextrin and graphene oxide are ultrasonically treated in water for 2 hours, and then vacuum dried to obtain unsaturated β-cyclodextrin covalently modified graphene oxide, and the product is an unsaturated "β-cyclodextrin-graphene oxide" supramolecular hybrid.

[0078] Preparation of S200 and A solution

[0079] 0.25 parts of sodium D-isoascorbate and 0.6 parts of 4-mercaptophenylacetic acid were mixed and stirred evenly with deionized water to prepare a liquid A with a mass fraction of 7.5%.

[0080] Preparation of S300 and B solution

[0081] 20 parts of acrylic acid and 10 parts of octylphenol polyoxyethylene ether acrylate were mixed and stirred evenly with deionized water to prepare a liquid B with a mass fraction of 22%.

[0082] Preparation of S400, sulfate-resistant polycarboxylate water reducer

[0083] At 15° C., 300 parts of isopentenyl polyethylene glycol ether and 17-unsaturated “β-cyclodextrin-graphene oxide supramolecular hybrid” were mixed and stirred uniformly with deionized water;

[0084] Then add 6 parts of peracetic acid and stir evenly to obtain a mixed solution with a mass fraction of 60%;

[0085] The A solution was dripped into the mixed solution at a uniform speed for 60 minutes;

[0086] After adding the A solution for 5 minutes, add the B solution at a uniform speed for 75 minutes;

[0087] After the addition is completed, keep warm for 30 minutes;

[0088] After the heat preservation reaction is completed, a sodium hydroxide solution with a mass fraction of 32% is added dropwise to adjust the pH to 5.2 to obtain the sulfate-resistant polycarboxylate water-reducing agent.

[0089] Example 4

[0090] Embodiment 4 of the present invention provides a sulfate-resistant polycarboxylate water-reducing agent, which is prepared by the following steps:

[0091] S100, preparation of unsaturated "β-cyclodextrin-graphene oxide supramolecular hybrid":

[0092] S101, weigh β-cyclodextrin and NaOH in a molar ratio of 8.0:0.2, add them into a 500 mL round-bottom flask, and add 250 mL of distilled water until the solid is dissolved;

[0093] S102, place the flask in an ice water bath (1.5°C), and add 13 mL of acryloyl chloride into the flask using a constant pressure funnel. After stirring for 30 minutes, acryloyl-modified unsaturated β-cyclodextrin is obtained;

[0094] Purification process of unsaturated β-cyclodextrin:

[0095] After filtering the solution, it was dried under reduced pressure at 40 °C, and then the crude product was dissolved in 17 mL of N, N-dimethylformamide and filtered to remove the sodium chloride;

[0096] 200 mL of acetone was added to the filtrate, and the precipitate was collected and dissolved in 20 ml of methanol, followed by the addition of 200 mL of acetone and the collection of the precipitate. The obtained product was dried under reduced pressure at 40 ° C for 5 hours to obtain unsaturated β-cyclodextrin;

[0097] S103. Unsaturated β-cyclodextrin and graphene oxide are ultrasonically treated in water for 2 hours, and then vacuum dried to obtain unsaturated β-cyclodextrin covalently modified graphene oxide, and the product is an unsaturated "β-cyclodextrin-graphene oxide" supramolecular hybrid.

[0098] Preparation of S200 and A solution

[0099] 0.25 parts of L-ascorbic acid-2-sodium phosphate and 0.65 parts of 4-mercaptophenylacetic acid were mixed and stirred evenly with deionized water to prepare a liquid A with a mass fraction of 7.5%.

[0100] Preparation of S300 and B solution

[0101] 20 parts of acrylic acid and 10 parts of octylphenol polyoxyethylene ether acrylate were mixed and stirred evenly with deionized water to prepare a liquid B with a mass fraction of 22%.

[0102] Preparation of S400, sulfate-resistant polycarboxylate water reducer

[0103] At 15° C., 280 parts of isobutylene alcohol polyoxyethylene ether and 20 parts of unsaturated “β-cyclodextrin-graphene oxide supramolecular hybrid” were mixed and stirred evenly with deionized water;

[0104] Then add 6 parts of peracetic acid and stir evenly to obtain a mixed solution with a mass fraction of 60%;

[0105] The A solution was dripped into the mixed solution at a uniform speed for 60 minutes;

[0106] After adding the A solution for 5 minutes, add the B solution at a uniform speed for 75 minutes;

[0107] After the addition is completed, keep warm for 30 minutes;

[0108] After the heat preservation reaction is completed, a sodium hydroxide solution with a mass fraction of 32% is added dropwise to adjust the pH to 5.2 to obtain the sulfate-resistant polycarboxylate water-reducing agent.

[0109] Comparative Example 1

[0110] Comparative Example 1 is a commercially available concrete anti-sulfate corrosion preservative, and the specific product information is from Sino-German Xinya Building Materials Co., Ltd. Its components include: polymer, expansion agent, inorganic filler, etc.

[0111] Comparative Example 2

[0112] Comparative Example 2 is a commercially available anti-sulfate admixture, and the specific product information is DC-K1006 from Beijing Dechang Weiye Construction Engineering Technology Co., Ltd., and its components include: inorganic mineral materials and powdered polycarboxylic acid water reducer.

[0113] Comparative Example 3

[0114] Comparative Example 3 is a commercially available concrete anti-sulfate corrosion preservative, and the specific product information is Laishui County Haiyan Xingye Concrete Admixture Processing Co., Ltd., and its components include: expansion agent, silica fume, mineral powder, etc.

[0115] Comparative Example 4

[0116] The other steps and materials are the same as those in Example 1, except that the unsaturated "β-cyclodextrin-graphene oxide" supramolecular hybrid prepared in step S100 is not added when preparing the sulfate-resistant polycarboxylate water-reducing agent.

[0117] Comparative Example 5

[0118] The other steps and materials are the same as those in Example 1, except that octylphenol polyoxyethylene ether acrylate is replaced with a common unsaturated ester (hydroxyethyl acrylate) when preparing the sulfate-resistant polycarboxylate water-reducing agent.

[0119] Comparative Example 6

[0120] The other steps and materials are the same as those in Example 1, except that in step 100, graphene oxide is not added.

[0121] Test example

[0122] The sulfate-resistant polycarboxylate water reducers provided in Examples 1 to 4 of the present invention and commercially available different types of concrete sulfate-resistant preservatives provided in Comparative Examples 1 to 3, as well as Comparative Examples 4 to 6, were prepared with the same water reducer and mixed into concrete to conduct a concrete sulfate resistance test.

[0123] Table 1 Concrete mix ratio (kg / m 3 )

[0124]

[0125] The difference between the comparative example and the embodiment is:

[0126] Examples 1 to 4 have an excellent water-reducing rate of sulfate-resistant water-reducing agents, and no other sulfate-resistant agents are added to their concrete mixes. The sulfate-resistant water-reducing agents in the comparative examples are not polycarboxylate water-reducing agents, and do not contain water-reducing components or contain very few water-reducing components. To ensure a consistent water-reducing agent dosage, comparative examples 1 to 3 use ordinary polycarboxylate water-reducing agents (BASF water-reducing agent 410).

[0127] In order to verify the performance difference between the sulfate-resistant polycarboxylate water-reducing agent provided in the above embodiments and the comparative sulfate-resistant preservative or sulfate-resistant admixture provided in the comparative example, the above sulfate-resistant water-reducing agent was used at a recommended dosage of 2.5% and subjected to a benchmark test in accordance with the performance index requirements in JC / T 1011-2021 "Concrete Anticorrosion Preservative". The experimental results are shown in Table 2 below.

[0128] Table 2 Performance indexes of various sulfate corrosion resistance agents in benchmark test

[0129]

[0130] In this test example, under the condition that the concrete mix ratio is constant and the solid content and dosage of the water reducing agent are consistent, the concrete anti-sulfate corrosion agent described in Examples 1 to 4 of the present invention and Comparative Examples 1 to 6 are added for comparison.

[0131] It can be seen from the test results in Table 2 that the initial setting and final setting times of the concrete mixed with the samples of Examples 1 to 4 and Comparative Examples 1 to 6 all meet the standard requirements.

[0132] However, for the 7d and 28d compressive strength of the concrete of Examples 1 to 4 compared with Comparative Examples 1 to 6, Examples 1 to 4 are significantly higher than Comparative Examples 1 to 6, which indicates that the addition of Examples 1 to 4 reduces the pores and micropores formed in the late stage of concrete curing to a certain extent, improves the compactness of concrete, and thus improves the 7d and 28d compressive strength of concrete. From the analysis of the corrosion resistance coefficient and the chloride ion diffusion coefficient, it can be seen that the corrosion resistance coefficient of the example sample is significantly greater than that of the comparative example, and the chloride ion diffusion coefficient is significantly less than that of the comparative example, which means that the example sample has an excellent "internal hydrophobic" effect, which can reduce the pores and micropores formed in the late stage of concrete curing, improve the compactness of concrete, reduce porosity and pore size, and reduce the sulfate erosion medium from entering the interior of the concrete by the method of internal and external blocking, thereby reducing the damage of the sulfate erosion medium to the durability of concrete. At the same time, the presence of the example sample further strengthens the bonding effect between the coarse aggregate and the cement paste, further improves the compactness of the concrete, and reduces the entry of the external sulfate solution.

[0133] Therefore, the sulfate-resistant polycarboxylate water-reducing agent product of the embodiment meets the compressive strength ratio and corrosion resistance indicators of JC / T 1011-2021 "Concrete Anti-Corrosion Preservative".

[0134] It should be noted that the specific parameters or some reagents in the above embodiments are specific embodiments or preferred embodiments of the present invention, rather than limiting the present invention; those skilled in the art can make adaptive adjustments within the scope of the present invention.

Claims

1. A sulfate-resistant polycarboxylate water-reducing agent, characterized in that: The raw materials for preparing the sulfate-resistant polycarboxylate water-reducing agent include, by weight:

2. The sulfate-resistant polycarboxylate water-reducing agent according to claim 1, characterized in that: The raw materials for preparing the unsaturated "β-cyclodextrin-graphene oxide" supramolecular hybrid include: β-cyclodextrin, alkali, acryloyl chloride, graphene oxide and water.

3. The sulfate-resistant polycarboxylate water-reducing agent according to claim 2, characterized in that: The preparation steps of the unsaturated "β-cyclodextrin-graphene oxide" supramolecular hybrid include: Mix β-cyclodextrin, alkali and water to obtain an alkaline solution; Adding acryloyl chloride to the alkaline solution to obtain unsaturated β-cyclodextrin after modification with acryloyl chloride; The unsaturated β-cyclodextrin and graphene oxide are subjected to ultrasonic treatment to obtain the unsaturated "β-cyclodextrin-graphene oxide" supramolecular hybrid.

4. The sulfate-resistant polycarboxylate water-reducing agent according to claim 2, characterized in that: The molar ratio of the β-cyclodextrin to the base is (7.0-8.5):(0.1-0.25).

5. The sulfate-resistant polycarboxylate water-reducing agent according to claim 1, characterized in that: The unsaturated polyether macromonomer includes at least one of ethoxy vinyl polyethylene glycol ether, isopentenyl polyethylene glycol ether and isobutylene alcohol polyoxyethylene ether, and has a molecular weight of 2000-3500.

6. The sulfate-resistant polycarboxylate water-reducing agent according to claim 1, characterized in that: The oxidant includes at least one of peracetic acid, hydrogen peroxide and ammonium persulfate.

7. The sulfate-resistant polycarboxylate water-reducing agent according to claim 1, characterized in that: The reducing agent includes at least one of L-ascorbic acid-2-phosphate sodium salt, 5,6-isopropylidene-L-ascorbic acid and sodium D-isoascorbate.

8. The sulfate-resistant polycarboxylate water-reducing agent according to claim 1, characterized in that: The chain transfer agent includes at least one of 4-mercaptophenylacetic acid, 2-(ethylthio)acetic acid and 4-mercaptophenylacetic acid.

9. A method for preparing the sulfate-resistant polycarboxylate water-reducing agent according to any one of claims 1 to 8, comprising the steps of: The unsaturated polyether macromonomer, unsaturated "β-cyclodextrin-graphene oxide" supramolecular hybrid, oxidant, reductant, chain transfer agent, unsaturated acid and octylphenol polyoxyethylene ether acrylate are mixed and reacted to obtain the sulfate-resistant polycarboxylic acid water-reducing agent.

10. Use of the sulfate-resistant polycarboxylate water-reducing agent according to any one of claims 1 to 8 in concrete.

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