Preparation method of high-workability and strong-dispersion type water reducing agent

Abstract

The invention provides a preparation method of a high-workability strong-dispersion type water reducing agent, which comprises the following steps: dissolving an unsaturated polyether monomer A, a prepolymer B and an oxidizing agent in deionized water, and uniformly stirring to obtain a base material; a reducing agent and a chain transfer agent are added into deionized water to be dissolved and evenly stirred, and a solution (1) is obtained; an unsaturated acid monomer C, an unsaturated amide monomer D and an unsaturated silane monomer E are added into deionized water to be dissolved and evenly stirred, and a solution (2) is obtained; dropwise adding the solution (1) and the solution (2) into the base material, and keeping the temperature after dropwise adding; and cooling to room temperature, adding an alkaline compound to adjust the pH value, and adding water to adjust the solid content, thereby obtaining the high-workability strong-dispersion type water reducing agent. The water reducing agent solves the problem of low conversion rate caused by low reaction activity of maleic acid (anhydride) or fumaric acid, so that the problem of storage stability of the water reducing agent is solved, and the obtained water reducing agent has high workability and strong dispersity.

Description

Technical Field

[0001] The invention belongs to the field of concrete admixtures, relates to a water reducing agent, and in particular to a preparation method of a highly workable and highly dispersed water reducing agent suitable for solid waste-based concrete. Background Art

[0002] With the development of modern engineering technology, ultra-high-rise and long-distance transportation of concrete has become the norm in engineering construction. The long-distance transportation of concrete in the pump pipe puts higher and higher requirements on the rheology of the mixture. With the gradual scarcity of natural sand, machine-made sand has been widely used in the production of concrete. Due to the limitations of equipment and process, machine-made sand is often graded as "more at both ends and less in the middle". The lack of intermediate aggregate particles, which plays a vital role in the performance indicators of concrete such as encapsulation and cohesion, makes concrete prone to bleeding, slurry leakage and even segregation, increasing the risk of pump blockage during pumping and affecting the quality of the project.

[0003] On the other hand, with the rapid development of industry, a large amount of solid waste has been generated, such as fly ash, carbide slag, desulfurized gypsum, steel slag, slag, limestone powder, etc. These solid wastes have adverse effects on the natural environment, land resources and people's living environment. In the past decade, industrial solid waste has been widely studied and applied in cementitious materials. In order to improve the activity of cementitious materials made from industrial solid waste in concrete, a combination of physical excitation (grinding) and chemical excitation (activator) is generally used. However, the fineness of solid waste particles after grinding is greatly improved. In addition, the application of chemical activators often leads to high water demand and poor workability when used in concrete. For example, fly ash with a "ball effect" composed of spherical particles can improve the fluidity and workability of concrete when used in concrete, but after grinding, the spherical particles are destroyed, resulting in a decrease in fluidity ratio and poor workability. For example, the addition of desulfurized gypsum increases the competitive adsorption with polycarboxylic acid water reducer and reduces the dispersion effect of the water reducer. At the same time, since the early activity of solid waste-based concrete is generally low, it is easy to cause low early strength of concrete, affecting the progress of the project.

[0004] Therefore, in the face of the complex and diverse construction environment of modern engineering and the current application status of low-quality aggregates and multi-component cementitious materials in concrete, it is necessary to develop a polycarboxylic acid water reducer that can solve many problems such as high water demand, poor workability, competitive adsorption and early strength. Literature research shows that maleic acid (anhydride) and fumaric acid can effectively adjust the workability of concrete in water reducer molecules, but due to the low reactivity of the two, the conversion rate is low and it is difficult to achieve a good dispersion effect. At the same time, maleic acid (anhydride) and fumaric acid that do not participate in the reaction are easy to precipitate, and the storage stability of the prepared water reducer is also poor. Summary of the invention

[0005] In view of the above-mentioned deficiencies in the prior art, the present invention provides a highly workable and highly dispersible water reducer, which solves the problem of low conversion rate caused by low reaction activity of maleic acid (anhydride) or fumaric acid, thereby solving the problem of storage stability of the water reducer, and makes the obtained water reducer have high workability and strong dispersibility.

[0006] The technical solution adopted to achieve the above-mentioned purpose of the present invention is:

[0007] A method for preparing a highly workable and highly dispersible water reducing agent comprises the following steps: (1) preparing a base material: adding an unsaturated polyether monomer A, a prepolymer B, and an oxidant into a reactor, adding deionized water to dissolve the mixture, and stirring the mixture to be uniform;

[0008] (2) Solution ① Preparation: Weigh the reducing agent and chain transfer agent, add deionized water to dissolve and stir evenly;

[0009] (3) Preparation of solution ②: weigh unsaturated acid monomer C, unsaturated amide monomer D and unsaturated silane monomer E, add deionized water to dissolve and stir evenly;

[0010] (4) Synthesis reaction: Simultaneously add solutions ① and ② to the reactor containing the primer, the addition time is 0.5 to 4 hours, the reaction temperature is controlled at 15 to 45°C, and the total mass concentration of each reactant is controlled at 40 to 60%. After the addition of solution ① and solution ② is completed, keep warm for 0.5 to 2 hours; cool to room temperature, add an alkaline compound to adjust the pH to 6.5 to 7.5, and add water to adjust the solid content to 40 to 50%, thereby obtaining a highly workable and highly dispersed water reducer.

[0011] The mass ratio of monomer A to prepolymer B is 1:(0.1-2); the molar ratio of monomers A, C, D, and E is 1:(2-5):(1-4):(0.5-2); the oxidant accounts for 1-5% of the total molar amount of all reactive monomers; the reducing agent accounts for 0.1-3% of the total molar amount of all reactive monomers; and the chain transfer agent accounts for 0.5-3% of the total molar amount of all reactive monomers.

[0012] The preparation method of the prepolymer B is as follows: unsaturated polyether monomer F, unsaturated acid monomer G, oxidant and deionized water are added into a reactor, stirred evenly and heated to 30-60° C.; an aqueous solution of a reducing agent is added dropwise for 2-5 hours, and after the addition is completed, the mixture is kept warm for 1-2 hours, cooled to room temperature, and water is added to adjust the solid content to 40-50%, so as to obtain the prepolymer B: the molar ratio of the unsaturated acid monomer G to the unsaturated polyether monomer F is (1-3):1, the oxidant accounts for 1-4% of the total molar amount of the monomers F and G, and the reducing agent accounts for 0.1-4% of the total molar amount of the monomers F and G.

[0013] The unsaturated polyether monomer F is isopentanol polyoxyethylene ether with a molecular weight of 2000-6000; the unsaturated acid monomer G is at least one of maleic acid (anhydride) or fumaric acid.

[0014] The oxidant is at least one of peracetic acid, hydrogen peroxide, benzoyl peroxide, potassium persulfate, ammonium persulfate, and sodium persulfate; the reducing agent is at least one of bleaching powder, sodium bisulfite, sodium pyrosulfite, ferrous sulfate, ferrous pyrophosphate, sodium hypophosphite, and L-ascorbic acid.

[0015] The unsaturated polyether monomer A is one or a mixture of two or more of methyl allyl polyoxyethylene ether, isopentanol polyoxyethylene ether and ethylene glycol monovinyl polyoxyethylene ether.

[0016] The unsaturated acid C is at least one of acrylic acid and methacrylic acid.

[0017] The unsaturated amide monomer D is one or a mixture of two or more of acrylamide, N-vinyl caprolactam, N,N-dimethylacrylamide, N,N-diethylacrylamide, N-isopropylacrylamide, N-vinylpyrrolidone, N-vinylacetamide, N-vinylformamide or N-methyl-N-vinylacetamide.

[0018] The unsaturated silane monomer E is one or a mixture of two or more of γ-methacryloxypropyltrimethoxysilane, methylvinyldimethoxysilane, methylvinyldiethoxysilane, methyldiethoxysilane, vinyltrichlorosilane, vinylphenyldiethoxysilane, vinyldimethoxymethylsilane, vinyltrimethoxysilane, vinyltriethoxysilane, allyltrimethoxysilane, allyltriethoxysilane or allyltrichlorosilane, and vinyltri(2-methoxyethoxy)silane.

[0019] The chain transfer agent is at least one of mercaptoacetic acid, 2-mercaptopropionic acid, 3-mercaptopropionic acid, mercaptoethanol, mercaptopropanol, sodium methacrylate sulfonate, dodecyl mercaptan, undecyl mercaptan, hexadecyl mercaptan, octadecyl mercaptan, sodium hypophosphite, isopropyl alcohol, trisodium phosphate, sodium formate, and sodium acetate;

[0020] The alkaline compound is at least one of ammonia water and alkali metal hydroxide.

[0021] Compared with the prior art, the highly workable and highly dispersed water reducer provided by the present invention has the following advantages: 1. Based on the molecular structure design theory, the present invention uses the reactants of maleic acid (anhydride) or fumaric acid and unsaturated polyether as prepolymers to participate in the secondary polymerization reaction of the high reaction activity system, thereby ensuring that maleic acid (anhydride) and fumaric acid fully participate in the reaction, solving the problem of low conversion rate due to low reaction activity, solving the problem of storage stability of the water reducer, and successfully introducing it into the polycarboxylic acid water reducer system to enable it to play a workability regulating role.

[0022] 2. In the present invention, the unsaturated monomer having a silane group and an amide group reacts with an unsaturated acid and an unsaturated polyether. After hydrolysis, the silane group can undergo condensation with the hydroxyl group on the surface of the cementitious material particles to produce chemical adsorption, thereby enhancing the adsorption competitiveness of the polycarboxylic acid water-reducing agent in a complex cementitious material system and providing a guarantee for the dispersion effect; the amide group can provide better workability and early strength function. DETAILED DESCRIPTION

[0023] The following examples describe in more detail the preparation process of the highly workable and highly dispersed water reducing agent of the present invention, and these examples are given in an illustrative manner so that technicians familiar with this project can understand the content of the present invention and implement it, but these examples do not limit the scope of protection of the present invention. All equivalent changes or modifications made according to the spirit and essence of the present invention should be included in the scope of protection of the present invention.

[0024] Example 1

[0025] The highly workable and highly dispersible water reducer provided in this embodiment is prepared by the following method:

[0026] (1) Preparation of prepolymer: In a four-necked flask equipped with a stirrer, a thermometer, a constant flow pump and a condenser reflux tube, 300 g (0.125 mol) of isopentanol polyoxyethylene ether with a molecular weight of 2400, 24.5 g (0.25 mol) of maleic anhydride, 300 g of deionized water, and 1.39 g (0.01125 mol) of 27.5% hydrogen peroxide were added, stirred evenly and heated to 60° C. A solution consisting of 0.33 g (0.001875 mol) of L-ascorbic acid and 30 g of deionized water was added dropwise for 3 h. After the addition was completed, the mixture was kept warm for 1 h, 65 g of deionized water was added, the solid content was adjusted to 45%, and the mixture was cooled to room temperature to obtain a prepolymer.

[0027] (2) Preparation of base material: In a four-necked flask equipped with a stirrer, a thermometer and a constant flow pump, add 300 g (0.1 mol) of ethylene glycol monovinyl polyoxyethylene ether with a molecular weight of 3000, 100 g of prepolymer, 1.61 g (0.00706 mol) of ammonium persulfate and 244 g of deionized water, stir evenly and control the temperature at 15°C.

[0028] (3) Solution ① Preparation: Weigh 0.2714 g (0.0023 mol) of bleaching powder and 1.166 g (0.011 mol) of 3-mercaptopropionic acid, add 20 g of deionized water to dissolve and stir evenly.

[0029] (4) Preparation of solution ②: Weigh 14.4 g (0.2 mol) of acrylic acid, 7.1 g (0.1 mol) of acrylamide, 12.4 g (0.05 mol) of γ-methacryloxypropyltrimethoxysilane and 20 g of deionized water, dissolve them and stir them evenly.

[0030] (5) Synthesis reaction: Solution ① and ② were added to the four-necked flask with the primer at the same time. Solution ① was added for 70 min, and solution ② was added for 60 min. After the addition was completed, the mixture was kept warm for 1 h, cooled to room temperature, and NaOH was added to adjust the pH to 7.0. 50 g of deionized water was added to adjust the solid content of the solution to 50%, and a highly workable and highly dispersed water reducer PCE-1 was obtained.

[0031] Example 2

[0032] The highly workable and highly dispersible water reducer provided in this embodiment is prepared by the following method:

[0033] (1) Preparation of prepolymer: In a four-necked flask equipped with a stirrer, a thermometer, a constant flow pump and a condenser reflux tube, add 280 g (0.1 mol) of isopentanol polyoxyethylene ether with a molecular weight of 2800, 34.8 g (0.3 mol) of fumaric acid, 245 g of deionized water, and 2.7 g (0.01 mol) of potassium persulfate, stir evenly and heat to 45° C. Add a solution consisting of 0.416 g (0.004 mol) of sodium bisulfite and 30 g of deionized water dropwise for 3.5 h. After the addition is completed, keep the temperature for 1 h, add 37 g of deionized water, adjust the solid content to 50%, and cool to room temperature to obtain a prepolymer.

[0034] (2) Preparation of base material: In a four-necked flask equipped with a stirrer, a thermometer and a constant flow pump, add 300 g (0.125 mol) of methyl allyl polyoxyethylene ether with a molecular weight of 2400, 120 g of prepolymer, 3.50 g (0.046 mol) of peracetic acid and 234 g of deionized water, stir evenly and control the temperature at 25°C.

[0035] (3) Preparation of solution ①: Weigh 1.368 g (0.009 mol) of ferrous sulfate and 1.932 g (0.021 mol) of thioglycolic acid, add 20 g of deionized water to dissolve and stir evenly.

[0036] (4) Preparation of solution ②: Weigh 37.625 g (0.4375 mol) of methacrylic acid, 24.75 g (0.25 mol) of N,N-dimethylacrylamide, 13.2 g (0.1 mol) of methylvinyldimethoxysilane and 46 g of deionized water, dissolve and stir evenly.

[0037] (5) Synthesis reaction: Solution ① and ② were added to the four-necked flask with the primer at the same time. The addition time of solution ① was 140 min, and the addition time of solution ② was 120 min. After the addition was completed, the mixture was kept warm for 1.5 h, cooled to room temperature, and ammonia water was added to adjust the pH to 7.0. 75 g of deionized water was added to adjust the solid content of the solution to 50%, and a highly workable and highly dispersed water reducer PCE-2 was obtained.

[0038] Example 3

[0039] The highly workable and highly dispersible water reducer provided in this embodiment is prepared by the following method:

[0040] (1) Preparation of prepolymer: In a four-necked flask equipped with a stirrer, a thermometer, a constant flow pump and a condenser reflux tube, 320 g (0.08 mol) of isopentanol polyoxyethylene ether with a molecular weight of 4000, 18.56 g (0.16 mol) of maleic acid, 280 g of deionized water, and 1.666 g (0.007 mol) of sodium persulfate were added, stirred evenly and heated to 55° C. A solution consisting of 0.4224 g (0.0048 mol) of sodium hypophosphite and 30 g of deionized water was added dropwise for 4 h. After the addition was completed, the mixture was kept warm for 1 h, 24 g of deionized water was added, the solid content was adjusted to 50%, and the mixture was cooled to room temperature to obtain a prepolymer.

[0041] (2) Preparation of base material: In a four-necked flask equipped with a stirrer, a thermometer and a constant flow pump, add 280 g (0.07 mol) of isopentanol polyoxyethylene ether with a molecular weight of 4000, 240 g of prepolymer, 6.788 g (0.028 mol) of benzoyl peroxide and 230 g of deionized water, stir evenly and control the temperature to 45°C.

[0042] (3) Preparation of solution ①: Weigh 1.596 g (0.0056 mol) of ferrous pyrophosphate and 2.0382 g (0.0129 mol) of sodium methyl methacrylate sulfonate, add 35 g of deionized water to dissolve and stir evenly.

[0043] (4) Preparation of solution ②: Weigh 21.07 g (0.245 mol) of methacrylic acid, 11.9 g (0.14 mol) of N-vinyl acetamide, 8.288 g (0.056 mol) of vinyl trimethoxy silane and 50 g of deionized water, dissolve and stir evenly.

[0044] (5) Synthesis reaction: Solution ① and ② were added to the four-necked flask with the primer at the same time. Solution ① was added for 210 min, and solution ② was added for 180 min. After the addition was completed, the mixture was kept warm for 1 h, cooled to room temperature, potassium hydroxide was added to adjust the pH to 7.0, and 35 g of deionized water was added to adjust the solid content of the solution to 45%, thereby obtaining a highly workable and highly dispersed water reducer PCE-3.

[0045] Example 4

[0046] The highly workable and highly dispersible water reducer provided in this embodiment is prepared by the following method:

[0047] (1) Preparation of prepolymer: In a four-necked flask equipped with a stirrer, a thermometer, a constant flow pump and a condenser reflux tube, add 300 g (0.125 mol) of isopentanol polyoxyethylene ether with a molecular weight of 2400, 14.5 g (0.125 mol) of fumaric acid, 258 g of deionized water, and 1.21 g (0.005 mol) of benzoyl peroxide, stir evenly and heat to 60° C. Add dropwise a solution consisting of 0.57 g (0.00375 mol) of ferrous sulfate and 30 g of deionized water for 2.5 h. After the addition is completed, keep the temperature for 2 h, add 22 g of deionized water, adjust the solid content to 50%, and cool to room temperature to obtain a prepolymer.

[0048] (2) Preparation of base material: In a four-necked flask equipped with a stirrer, a thermometer and a constant flow pump, add 172 g (0.04 mol) of ethylene glycol monovinyl polyoxyethylene ether with a molecular weight of 4300, 320 g of prepolymer, 0.912 g (0.004 mol) of ammonium persulfate and 190 g of deionized water, stir evenly and control the temperature at 20°C.

[0049] (3) Preparation of solution ①: Weigh 0.352 g (0.002 mol) of L-ascorbic acid and 1.616 g (0.008 mol) of dodecyl mercaptan, add 35 g of deionized water to dissolve and stir evenly.

[0050] (4) Preparation of solution ②: Weigh 6.336 g (0.088 mol) of acrylic acid, 5.424 g (0.048 mol) of N-isopropylacrylamide, 6.48 g (0.04 mol) of allyltrimethoxysilane and 50 g of deionized water, dissolve them and stir them evenly.

[0051] (5) Synthesis reaction: Solution ① and ② were added to the four-necked flask with the primer at the same time. Solution ① was added for 60 min, and solution ② was added for 50 min. After the addition was completed, the mixture was kept warm for 30 min, cooled to room temperature, sodium hydroxide was added to adjust the pH to 7.0, and 88 g of deionized water was added to adjust the solid content of the solution to 40%, thereby obtaining a highly workable and highly dispersed water reducer PCE-4.

[0052] Comparative Example 1

[0053] The materials used in this comparative example are all the same as those in Example 1. In this comparative example, no prepolymerization is performed, but a direct polymerization method is used to synthesize the water reducer. The specific preparation method is as follows:

[0054] (1) Preparation of base material: In a reaction kettle equipped with a stirrer, a thermometer and a constant flow pump, 300 g (0.1 mol) of isopentanol polyoxyethylene ether with a molecular weight of 3000, 3.78 g (0.0385 mol) of maleic anhydride equivalent to the amount used in the prepolymer in Example 1, 1.61 g (0.00706 mol) of ammonium persulfate and 244 g of deionized water were added, stirred evenly and the temperature was controlled at 15°C.

[0055] (2) Solution ① Preparation: Weigh 0.277 g (0.0023 mol) of bleaching powder and 1.166 g (0.011 mol) of 3-mercaptopropionic acid, add 20 g of deionized water to dissolve and stir evenly.

[0056] (3) Preparation of solution ②: Weigh 14.4 g (0.2 mol) of acrylic acid, 7.1 g (0.1 mol) of acrylamide, 12.4 g (0.05 mol) of γ-methacryloxypropyltrimethoxysilane and 20 g of deionized water, dissolve them and stir them evenly.

[0057] (5) Synthesis reaction: Solution ① and ② were added to the four-necked flask with the primer at the same time. Solution ① was added for 70 min, and solution ② was added for 60 min. After the addition was completed, the mixture was kept warm for 1 h, cooled to room temperature, and NaOH was added to adjust the pH to 7.0. 50 g of deionized water was added to adjust the solid content of the solution to 50%, thereby obtaining a water reducer PCE-A.

[0058] Comparative Example 2

[0059] The preparation method of the water reducing agent in this comparative example is basically the same as that in comparative example 1, except that the amount of maleic anhydride is increased in this comparative example. The specific preparation method is as follows:

[0060] (1) Preparation of base material: In a reaction kettle equipped with a stirrer, a thermometer and a constant flow pump, add 300 g (0.1 mol) of isopentanol polyoxyethylene ether with a molecular weight of 3000, 9.8 g (0.1 mol) of maleic anhydride, 1.61 g (0.00706 mol) of ammonium persulfate and 244 g of deionized water, stir evenly and control the temperature at 15°C.

[0061] (2) Solution ① Preparation: Weigh 0.277 g (0.0023 mol) of bleaching powder and 1.166 g (0.011 mol) of 3-mercaptopropionic acid, add 20 g of deionized water to dissolve and stir evenly.

[0062] (3) Preparation of solution ②: Weigh 14.4 g (0.2 mol) of acrylic acid, 7.1 g (0.1 mol) of acrylamide, 12.4 g (0.05 mol) of γ-methacryloxypropyltrimethoxysilane and 20 g of deionized water, dissolve them and stir them evenly.

[0063] (5) Synthesis reaction: Solution ① and ② were added to the four-necked flask with the primer at the same time. Solution ① was added for 70 min, and solution ② was added for 60 min. After the addition was completed, the mixture was kept warm for 1 h, cooled to room temperature, and NaOH was added to adjust the pH to 7.0. 50 g of deionized water was added to adjust the solid content of the solution to 50%, thereby obtaining a water reducer PCE-B.

[0064] The water reducers prepared in the above Examples 1 to 4 and Comparative Examples 1 to 2 were tested for molecular weight. The number average molecular weight of the water reducer in the present invention was tested using a Viscotek TDA305max multi-detector gel permeation chromatograph produced by Malvern, UK, with a mobile phase of 0.1 mol / L sodium nitrate solution, a flow rate of 0.7 mL / min, and a chromatographic column of A-Guard+1xA6000M. The test results are shown in the following table.

[0065]

[0066] As can be seen from the above table, compared with PCE-A and PCE-B that have not been subjected to secondary polymerization with a high-activity reaction system, the water reducer prepared in the present invention has a significantly improved conversion rate. In addition, the water reducers prepared in Examples 1 to 4 have excellent storage properties and can be stored for a long time at room temperature.

[0067] Application Examples

[0068] The water reducing agent is applied to C30 and C60 solid waste-based concrete, wherein the components of C30 and C60 solid waste-based concrete are:

[0069]

[0070] The cement in the formula is Yadong P·O42.5, and the main components of solid waste-based cementitious materials are fly ash, slag, stone powder and gypsum, with a specific surface area of ​​693m 2 / kg, the fineness modulus of machine-made sand is 3.3, the fineness modulus of river sand is 2.6, the gravel is 5-25mm continuously graded gravel, and the water is tap water.

[0071] The water reducers prepared in the above Examples 1 to 4 and Comparative Examples 1 to 2 were applied to the C30 and C60 solid waste-based concretes in the above table, and the concretes were tested for performance. The concrete performance test in the present invention was conducted in accordance with GB8076-2008 "Concrete Admixtures", and the water reducer dosage was the dosage when the water reducer was diluted to a concentration of 10%. The test results are shown in the following table.

[0072]

[0073] It can be seen from the data in the above table that the water reducing agents prepared in Examples 1 to 4 have better initial dispersion performance when applied to concrete.

Claims

1. A method for preparing a highly workable and highly dispersible water reducing agent, characterized in that The following steps are involved: (1) Preparation of base material: unsaturated polyether monomer A, prepolymer B and oxidant are added into a reactor, deionized water is added to dissolve and stirred evenly; (2) Solution ① Preparation: Weigh the reducing agent and chain transfer agent, add deionized water to dissolve and stir evenly; (3) Preparation of solution ②: weigh unsaturated acid monomer C, unsaturated amide monomer D and unsaturated silane monomer E, add deionized water to dissolve and stir evenly; (4) Synthesis reaction: Simultaneously add solutions ① and ② to the reactor containing the primer, the addition time is 0.5 to 4 hours, the reaction temperature is controlled at 15 to 45°C, and the total mass concentration of each reactant is controlled at 40 to 60%. After the addition of solution ① and solution ② is completed, keep warm for 0.5 to 2 hours; cool to room temperature, add an alkaline compound to adjust the pH to 6.5 to 7.5, and add water to adjust the solid content to 40 to 50%, thereby obtaining a highly workable and highly dispersed water reducer.

2. The method for preparing a highly workable and highly dispersible water reducing agent according to claim 1, characterized in that: The mass ratio of monomer A to prepolymer B is 1:(0.1-2); the molar ratio of monomers A, C, D, and E is 1:(2-5):(1-4):(0.5-2); the oxidant accounts for 1-5% of the total molar amount of all reactive monomers; the reducing agent accounts for 0.1-3% of the total molar amount of all reactive monomers; and the chain transfer agent accounts for 0.5-3% of the total molar amount of all reactive monomers.

3. The method for preparing a highly workable and highly dispersible water reducing agent according to claim 1, characterized in that: The preparation method of the prepolymer B is as follows: unsaturated polyether monomer F, unsaturated acid monomer G, oxidant and deionized water are added into a reactor, stirred evenly and heated to 30-60° C.; an aqueous solution of a reducing agent is added dropwise for 2-5 hours, and after the addition is completed, the mixture is kept warm for 1-2 hours, cooled to room temperature, and water is added to adjust the solid content to 40-50%, so as to obtain the prepolymer B: the molar ratio of the unsaturated acid monomer G to the unsaturated polyether monomer F is (1-3):1, the oxidant accounts for 1-4% of the total molar amount of the monomers F and G, and the reducing agent accounts for 0.1-4% of the total molar amount of the monomers F and G.

4. The method for preparing the highly workable and highly dispersible water reducing agent according to claim 3, characterized in that: The unsaturated polyether monomer F is isopentanol polyoxyethylene ether with a molecular weight of 2000-6000; the unsaturated acid monomer G is at least one of maleic acid (anhydride) or fumaric acid.

5. The method for preparing the highly workable and highly dispersible water reducing agent according to claim 1 or 3, characterized in that: The oxidant is at least one of peracetic acid, hydrogen peroxide, benzoyl peroxide, potassium persulfate, ammonium persulfate, and sodium persulfate; the reducing agent is at least one of bleaching powder, sodium bisulfite, sodium pyrosulfite, ferrous sulfate, ferrous pyrophosphate, sodium hypophosphite, and L-ascorbic acid.

6. The method for preparing a highly workable and highly dispersible water reducing agent according to claim 1, characterized in that: The unsaturated polyether monomer A is one or a mixture of two or more of methyl allyl polyoxyethylene ether, isopentanol polyoxyethylene ether and ethylene glycol monovinyl polyoxyethylene ether.

7. The method for preparing a highly workable and highly dispersible water reducing agent according to claim 1, characterized in that: The unsaturated acid C is at least one of acrylic acid and methacrylic acid.

8. The method for preparing a highly workable and highly dispersible water reducing agent according to claim 1, characterized in that: The unsaturated amide monomer D is one or a mixture of two or more of acrylamide, N-vinyl caprolactam, N,N-dimethylacrylamide, N,N-diethylacrylamide, N-isopropylacrylamide, N-vinylpyrrolidone, N-vinylacetamide, N-vinylformamide or N-methyl-N-vinylacetamide.

9. The method for preparing a highly workable and highly dispersible water reducing agent according to claim 1, characterized in that: The unsaturated silane monomer E is one or a mixture of two or more of γ-methacryloxypropyltrimethoxysilane, methylvinyldimethoxysilane, methylvinyldiethoxysilane, methyldiethoxysilane, vinyltrichlorosilane, vinylphenyldiethoxysilane, vinyldimethoxymethylsilane, vinyltrimethoxysilane, vinyltriethoxysilane, allyltrimethoxysilane, allyltriethoxysilane or allyltrichlorosilane, and vinyltri(2-methoxyethoxy)silane.

10. The method for preparing a highly workable and highly dispersible water reducing agent according to claim 1, characterized in that: The chain transfer agent is at least one of thioglycolic acid, 2-mercaptopropionic acid, 3-mercaptopropionic acid, mercaptoethanol, mercaptopropanol, sodium methyl acrylate sulfonate, dodecyl mercaptan, undecyl mercaptan, hexadecyl mercaptan, octadecyl mercaptan, sodium hypophosphite, isopropyl alcohol, trisodium phosphate, sodium formate, and sodium acetate; and the alkaline compound is at least one of ammonia water and alkali metal hydroxide.

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