A polycarboxylic acid type composite concrete water reducing agent and preparation method thereof

Abstract

The invention discloses a method for preparing a polycarboxylic acid type composite concrete water reducer, comprising the following steps: preparing an additive solid phase C; then mixing isopentenyl polyoxyethylene ether, ammonium persulfate and deionized water to form a mixed liquid A, mixing acrylic acid, 2-methyl-2-acrylic acid-2-hydroxyethyl ester phosphate and deionized water to form a mixed liquid B, and mixing 3-mercaptopropionic acid, vitamin C and deionized water to form a mixed liquid C; adding the solid phase C to the mixed liquid A, and then simultaneously dropping the mixed liquid B, mixed liquid C and hydrogen peroxide into the mixed liquid A, continuing to stir the mixed liquid for 2h at 60±2°C after the dropwise addition is completed, and then air cooling to room temperature to obtain the water reducer. The water reducer prepared by the method of the present invention has a high water reduction rate and can significantly improve the compressive strength of concrete.

Description

Technical Field

[0001] The invention relates to the technical field of water reducing agents, and in particular to a polycarboxylic acid type composite concrete water reducing agent and a preparation method thereof. Background Art

[0002] At present, the research direction of concrete additives is more inclined to "pollution-free and high-performance". Polycarboxylic acid water reducers are the most widely used and comprehensive products in concrete admixtures. Because polycarboxylic acid water reducers are comb-shaped in molecular structure, they have many advantages such as low dosage, low pollution, short required retarding time, high water reduction rate and low cost; they can be used to prepare high-strength, ultra-strength and high-fluidity self-compacting concrete. However, based on the current research status and market demand of polycarboxylic acid water reducers, the production and application of polycarboxylic acid water reducers still have the following problems: (1) The water reduction rate needs to be further improved. At present, the water reduction rate of commercially available polycarboxylic acid water reducers is generally around 24%, and the water reduction rate needs to be further improved to meet the broader market demand. (2) The problem of adaptability to admixtures. my country has a vast territory and great differences between the north and the south. Most polycarboxylic acid water reducers are difficult to meet the requirements of concrete raw materials in different regions. The development of polycarboxylic acid water reducers with good adaptability is what the market needs. Summary of the invention

[0003] To this end, the present invention provides a method for preparing a polycarboxylic acid type composite concrete water reducing agent, comprising the following steps:

[0004] (1) preparing a mixed aqueous solution of polyethylene glycol and sodium hydroxide; adding carboxymethyl chitosan to the sodium hydroxide solution to obtain a mixture, stirring the mixed aqueous solution of polyethylene glycol and sodium hydroxide, adding the mixture to the solution under stirring, stirring the solution in an ice-water bath for 15 to 18 minutes after the addition is completed, and then standing in a 55° C. water bath for solidification for 10 to 15 minutes, standing to complete solid-liquid separation, washing the solid phase with deionized water, and freeze-drying to obtain dispersed particles; adding the dispersed particles and grape seed proanthocyanidins to deionized water to obtain a mixed solution; adjusting the pH value of the mixed solution to 4 with dilute hydrochloric acid, stirring the mixed solution for more than 10 minutes, and then concentrating under reduced pressure, separating the solid and liquid, and freeze-drying the solid phase to obtain a solid phase A;

[0005] (2) adding the solid phase A to deionized water, and then adding polyethylene amine; stirring for more than 10 minutes after the addition is completed, and then adjusting the pH to 10 with hydrochloric acid or sodium hydroxide solution, adding a formaldehyde aqueous solution after the adjustment is completed, and keeping the water bath constant at 65±3° C. after the addition is completed, and keeping the temperature for more than 4 hours, condensing and reflux during the insulation process, and air cooling to room temperature after the insulation is completed, solid-liquid separation, washing the solid phase with deionized water, and drying at 60° C. for more than 30 minutes to obtain a solid phase B;

[0006] (3) preparing an ethanol solution of pyrophosphoric acid; adding the solid phase B to ethanol to form an alcohol suspension, keeping the alcohol suspension constant temperature at 70±3°C in a water bath, stirring the alcohol suspension for more than 10 minutes, then adding KH-550 to the alcohol suspension under stirring, stirring the alcohol suspension at 70±3°C for more than 10 minutes after the addition is completed, then adding deionized water under stirring, stirring the alcohol suspension at 70±3°C for more than 3 hours after the addition is completed, then adding the ethanol solution of pyrophosphoric acid under stirring, stirring the alcohol suspension at 70±3°C for more than 1 hour after the addition is completed, then air cooling to room temperature, solid-liquid separation, washing the solid phase with deionized water, and drying at 60°C for more than 30 minutes to obtain a solid phase C;

[0007] (4) Mixing isopentyl polyoxyethylene ether, ammonium persulfate and deionized water to form a mixed solution A, mixing acrylic acid, 2-methyl-2-acrylic acid-2-hydroxyethyl phosphate and deionized water to form a mixed solution B, and mixing 3-mercaptopropionic acid, vitamin C and deionized water to form a mixed solution C; adding the solid phase C to the mixed solution A, and then keeping the temperature at 60±2° C. in a water bath and stirring for more than 30 minutes, and then dropping the mixed solution B, mixed solution C and hydrogen peroxide into the mixed solution A while stirring, and after the dropping is completed, continue to keep the temperature at 60±2° C. and stir the mixed solution for more than 2 hours, and then air cool to room temperature to obtain the water reducing agent.

[0008] Furthermore, in the step (1), in the mixed aqueous solution of polyethylene glycol and sodium hydroxide, the mass percentage of polyethylene glycol is 20% to 22%, the concentration of the sodium hydroxide is 1 mol / L, and the solvent is water; carboxymethyl chitosan is added to the sodium hydroxide solution to obtain a mixture with a mass ratio of carboxymethyl chitosan: sodium hydroxide solution = 2:100, the concentration of the solute in the sodium hydroxide solution is 1 mol / L, and the solvent is water; the mass ratio of adding the mixture to the mixed aqueous solution of polyethylene glycol and sodium hydroxide is the mixture: the mixed aqueous solution of polyethylene glycol and sodium hydroxide = 1:8.

[0009] Furthermore, in the step (1), the mass ratio of the dispersed particles and grape seed proanthocyanidins added to deionized water is dispersed particles: grape seed proanthocyanidins: deionized water = 6-8:10-15:100; the mass percentage of the solute in the dilute hydrochloric acid is 10%, and the solvent is water.

[0010] Furthermore, in the step (2), the mass ratio of the solid phase A added to the deionized water is solid phase A: deionized water = 1:20; the mass ratio of the added polyvinylamine to the mass ratio of the added solid phase A is polyvinylamine: solid phase A = 0.3-0.5:1; the concentration of the solute in the hydrochloric acid is 0.5 mol / L, and the solvent is water; the concentration of the solute in the sodium hydroxide solution is 0.5 mol / L, and the solvent is water; the mass percentage of formaldehyde in the formaldehyde aqueous solution is 37%, and the volume ratio of the added formaldehyde aqueous solution to the mass ratio of the added solid phase A is formaldehyde aqueous solution: solid phase A = 0.8-1 mL: 1 g.

[0011] Furthermore, in the step (3), the concentration of pyrophosphoric acid in the ethanol solution of pyrophosphoric acid is 7-8 g / 100 mL, and the solvent is ethanol; the mass ratio of solid phase B added to ethanol is solid phase B:ethanol = 1:20; the mass ratio of KH-550, deionized water, and ethanol solution of pyrophosphoric acid added to the mass ratio of solid phase B is KH-550:deionized water:ethanol solution of pyrophosphoric acid:solid phase B = 0.6-0.8:0.5-0.6:3-4:1.

[0012] Furthermore, in the step (4), the mass ratio of the isopentenyl polyoxyethylene ether, ammonium persulfate, acrylic acid, 2-methyl-2-acrylic acid-2-hydroxyethyl ester phosphate, 3-mercaptopropionic acid, vitamin C, and solid phase C raw materials is isopentenyl polyoxyethylene ether: ammonium persulfate: acrylic acid: 2-methyl-2-acrylic acid-2-hydroxyethyl ester phosphate: 3-mercaptopropionic acid: vitamin C: solid phase C = 100: 1.4-1.5: 11-13: 3.2-4.2: 0.4-0.5: 0.4-0.6: 3- 4; the mass ratio of the isopentenyl polyoxyethylene ether mass and the deionized water in the mixed liquid A is isopentenyl polyoxyethylene ether: water = 100:70; the mass ratio of the acrylic acid mass and the deionized water in the mixed liquid B is acrylic acid: water = 11-13:7; the mass ratio of the vitamin C mass and the deionized water in the mixed liquid C is vitamin C: water = 0.4-0.6:90; the mass ratio of the hydrogen peroxide added mass and the mixed liquid A is hydrogen peroxide: mixed liquid A = 1.8-2:100, and the mass percentage of the solute in the hydrogen peroxide is 10%.

[0013] The beneficial effects of the present invention are that the water reducing agent prepared by the method of the present invention has a high water reducing rate and can significantly improve the compressive strength of concrete. DETAILED DESCRIPTION

[0014] The present invention will be further described below in conjunction with the embodiments.

[0015] Example 1

[0016] A method for preparing a polycarboxylic acid type composite concrete water reducing agent comprises the following steps:

[0017] (1) preparing a mixed aqueous solution of polyethylene glycol and sodium hydroxide; in the mixed aqueous solution of polyethylene glycol and sodium hydroxide, the mass percentage of polyethylene glycol is 20%, the concentration of the sodium hydroxide is 1 mol / L, and the solvent is water; adding carboxymethyl chitosan to the sodium hydroxide solution to obtain a mixture, the mass ratio of carboxymethyl chitosan to the sodium hydroxide solution to obtain the mixture is carboxymethyl chitosan: sodium hydroxide solution = 2:100, the concentration of the solute in the sodium hydroxide solution is 1 mol / L, and the solvent is water; stirring the mixed aqueous solution of polyethylene glycol and sodium hydroxide, adding the mixture to the solution under stirring, and adding the mixture to the mixed aqueous solution of polyethylene glycol and sodium hydroxide The mass ratio of the mixture is: polyethylene glycol: sodium hydroxide The mixed aqueous solution of sodium is 1:8; after the addition is completed, the solution is stirred under ice-water bath conditions for 15 minutes, and then allowed to stand and solidify in a 55°C water bath for 10 minutes, and allowed to stand to complete solid-liquid separation, the solid phase is washed with deionized water, and freeze-dried to obtain dispersed particles; the dispersed particles and grape seed proanthocyanidins are added to deionized water to obtain a mixed solution; the mass ratio of the dispersed particles and grape seed proanthocyanidins added to deionized water is dispersed particles: grape seed proanthocyanidins: deionized water = 6:10:100; the pH value of the mixed solution is adjusted to 4 with dilute hydrochloric acid, the mass percentage of the solute in the dilute hydrochloric acid is 10%, and the solvent is water; the mixed solution is stirred for 10 minutes, and then concentrated under reduced pressure to 1 / 5 of the volume before concentration, solid-liquid separation, and solid-phase freeze-dried to obtain solid phase A;

[0018] (2) adding the solid phase A to deionized water, wherein the mass ratio of the solid phase A to the deionized water is solid phase A: deionized water = 1:20; then adding polyvinylamine; the mass ratio of the added polyvinylamine to the added solid phase A is polyvinylamine: solid phase A = 0.3:1; stirring for 10 minutes after the addition is completed, and then adjusting the pH to 10 with hydrochloric acid or sodium hydroxide solution, wherein the concentration of the solute in the hydrochloric acid is 0.5 mol / L, and the solvent is water; the concentration of the solute in the sodium hydroxide solution is The solvent is 0.5 mol / L, and water is used as the solvent; after the adjustment, an aqueous solution of formaldehyde is added, the mass percentage of formaldehyde in the aqueous solution of formaldehyde is 37%, and the mass ratio of the added volume of the aqueous solution of formaldehyde to the added solid phase A is the aqueous solution of formaldehyde: solid phase A = 0.8 mL: 1 g; after the addition is completed, the water bath is kept at a constant temperature of 65±3°C, and the temperature is kept for 4 hours. During the temperature keeping process, condensation refluxes, and after the temperature keeping is completed, air cooling is performed to room temperature, solid-liquid separation is performed, the solid phase is washed with deionized water, and dried at 60°C for 30 minutes to obtain solid phase B;

[0019] (3) preparing an ethanol solution of pyrophosphoric acid; in the ethanol solution of pyrophosphoric acid, the concentration of pyrophosphoric acid is 7 g / 100 mL, and the solvent is ethanol; adding the solid phase B to ethanol to form an alcohol suspension, the mass ratio of solid phase B to ethanol is solid phase B: ethanol = 1:20; the alcohol suspension is kept at a constant temperature of 70±3° C. in a water bath, the alcohol suspension is stirred for 10 min, and then KH-550 is added to the alcohol suspension under stirring. After the addition is completed, the alcohol suspension is stirred at a constant temperature of 70±3° C. for 10 min, and then added under stirring After the addition of deionized water, the alcohol suspension was stirred at a constant temperature of 70±3°C for 3h, and then the ethanol solution of pyrophosphoric acid was added under stirring. After the addition of deionized water, the alcohol suspension was stirred at a constant temperature of 70±3°C for 1h. The mass ratio of the added mass of KH-550, deionized water, and ethanol solution of pyrophosphoric acid to the solid phase B was KH-550: deionized water: ethanol solution of pyrophosphoric acid: solid phase B = 0.6: 0.5: 3: 1; then air-cooled to room temperature, solid-liquid separation, the solid phase was washed with deionized water, and dried at 60°C for 30min to obtain solid phase C;

[0020] (4) Mixing isopentanyl polyoxyethylene ether, ammonium persulfate and deionized water to form a mixed liquid A, mixing acrylic acid, 2-methyl-2-acrylic acid-2-hydroxyethyl ester phosphate and deionized water to form a mixed liquid B, and mixing 3-mercaptopropionic acid, vitamin C and deionized water to form a mixed liquid C; adding the solid phase C to the mixed liquid A, and then stirring in a water bath at a constant temperature of 60±2° C. for 30 minutes, and then dropping the mixed liquid B, mixed liquid C and hydrogen peroxide into the mixed liquid A at the same time under stirring, wherein the mass ratio of the isopentanyl polyoxyethylene ether, ammonium persulfate, acrylic acid, 2-methyl-2-acrylic acid-2-hydroxyethyl ester phosphate, 3-mercaptopropionic acid, vitamin C and solid phase C is isopentanyl polyoxyethylene ether: ammonium persulfate: acrylic acid: 2-methyl-2-acrylic acid -2-hydroxyethyl phosphate: 3-mercaptopropionic acid: vitamin C: solid phase C = 100:1.4:11:3.2:0.4:0.4:3; the mass ratio of isopentanyl polyoxyethylene ether to deionized water in the mixed solution A is isopentanyl polyoxyethylene ether: water = 100:70; the mass ratio of acrylic acid to deionized water in the mixed solution B is acrylic acid: water = 11:7; the mass ratio of vitamin C to deionized water in the mixed solution C is vitamin C: water = 0.4:90; the mass ratio of the added mass of hydrogen peroxide to the mixed solution A is hydrogen peroxide: mixed solution A = 1.8:100, and the mass percentage of solute in the hydrogen peroxide is 10%; after the dropwise addition is completed, the mixed solution is continued to be stirred at 60±2°C for 2h, and then air-cooled to room temperature to obtain the water reducer.

[0021] Example 2

[0022] A method for preparing a polycarboxylic acid type composite concrete water reducing agent comprises the following steps:

[0023] (1) preparing a mixed aqueous solution of polyethylene glycol and sodium hydroxide; in the mixed aqueous solution of polyethylene glycol and sodium hydroxide, the mass percentage of polyethylene glycol is 20%, the concentration of the sodium hydroxide is 1 mol / L, and the solvent is water; adding carboxymethyl chitosan to the sodium hydroxide solution to obtain a mixture, the mass ratio of carboxymethyl chitosan to the sodium hydroxide solution to obtain the mixture is carboxymethyl chitosan: sodium hydroxide solution = 2:100, the concentration of the solute in the sodium hydroxide solution is 1 mol / L, and the solvent is water; stirring the mixed aqueous solution of polyethylene glycol and sodium hydroxide, adding the mixture to the solution under stirring, and adding the mixture to the mixed aqueous solution of polyethylene glycol and sodium hydroxide The mass ratio of the mixture is: polyethylene glycol: sodium hydroxide The mixed aqueous solution of sodium is 1:8; after the addition is completed, the solution is stirred under ice-water bath conditions for 15 minutes, and then allowed to stand and solidify in a 55°C water bath for 10 minutes, and allowed to stand to complete solid-liquid separation, the solid phase is washed with deionized water, and freeze-dried to obtain dispersed particles; the dispersed particles and grape seed proanthocyanidins are added to deionized water to obtain a mixed solution; the mass ratio of the dispersed particles and grape seed proanthocyanidins added to deionized water is dispersed particles: grape seed proanthocyanidins: deionized water = 7:12:100; the pH value of the mixed solution is adjusted to 4 with dilute hydrochloric acid, the mass percentage of the solute in the dilute hydrochloric acid is 10%, and the solvent is water; the mixed solution is stirred for 10 minutes, and then concentrated under reduced pressure to 1 / 5 of the volume before concentration, solid-liquid separation, and solid-phase freeze-dried to obtain solid phase A;

[0024] (2) adding the solid phase A to deionized water, wherein the mass ratio of the solid phase A to the deionized water is solid phase A: deionized water = 1:20; then adding polyvinylamine; the mass ratio of the added polyvinylamine to the added solid phase A is polyvinylamine: solid phase A = 0.4:1; stirring for 10 minutes after the addition is completed, and then adjusting the pH to 10 with hydrochloric acid or sodium hydroxide solution, wherein the concentration of the solute in the hydrochloric acid is 0.5 mol / L, and the solvent is water; the concentration of the solute in the sodium hydroxide solution is The solvent is 0.5 mol / L, and water is used as the solvent; after the adjustment, an aqueous solution of formaldehyde is added, the mass percentage of formaldehyde in the aqueous solution of formaldehyde is 37%, and the mass ratio of the added volume of the aqueous solution of formaldehyde to the added solid phase A is the aqueous solution of formaldehyde: solid phase A = 0.9 mL: 1 g; after the addition is completed, the water bath is kept at a constant temperature of 65±3°C, and the temperature is kept for 4 hours. During the heat preservation process, condensation reflux is carried out, and after the heat preservation is completed, air cooling is carried out to room temperature, solid-liquid separation is carried out, the solid phase is washed with deionized water, and dried at 60°C for 30 minutes to obtain solid phase B;

[0025] (3) preparing an ethanol solution of pyrophosphoric acid; in the ethanol solution of pyrophosphoric acid, the concentration of pyrophosphoric acid is 7 g / 100 mL, and the solvent is ethanol; adding the solid phase B to ethanol to form an alcohol suspension, the mass ratio of solid phase B to ethanol is solid phase B: ethanol = 1:20; the alcohol suspension is kept at a constant temperature of 70±3° C. in a water bath, the alcohol suspension is stirred for 10 min, and then KH-550 is added to the alcohol suspension under stirring. After the addition is completed, the alcohol suspension is stirred at a constant temperature of 70±3° C. for 10 min, and then added under stirring Deionized water, after the addition is completed, the alcohol suspension is stirred at a constant temperature of 70±3°C for 3h, and then the ethanol solution of pyrophosphoric acid is added under stirring. After the addition is completed, the alcohol suspension is stirred at a constant temperature of 70±3°C for 1h. The mass ratio of the added mass of KH-550, deionized water, and ethanol solution of pyrophosphoric acid to solid phase B is KH-550: deionized water: ethanol solution of pyrophosphoric acid: solid phase B = 0.7:0.5:3:1; then air-cooled to room temperature, solid-liquid separation, the solid phase is washed with deionized water, and dried at 60°C for 30min to obtain solid phase C;

[0026] (4) Mixing isopentanyl polyoxyethylene ether, ammonium persulfate and deionized water to form a mixed liquid A, mixing acrylic acid, 2-methyl-2-acrylic acid-2-hydroxyethyl ester phosphate and deionized water to form a mixed liquid B, and mixing 3-mercaptopropionic acid, vitamin C and deionized water to form a mixed liquid C; adding the solid phase C to the mixed liquid A, and then stirring in a water bath at a constant temperature of 60±2° C. for 30 minutes, and then dropping the mixed liquid B, mixed liquid C and hydrogen peroxide into the mixed liquid A at the same time under stirring, wherein the mass ratio of the isopentanyl polyoxyethylene ether, ammonium persulfate, acrylic acid, 2-methyl-2-acrylic acid-2-hydroxyethyl ester phosphate, 3-mercaptopropionic acid, vitamin C and solid phase C is isopentanyl polyoxyethylene ether: ammonium persulfate: acrylic acid: 2-methyl-2-acrylic acid -2-hydroxyethyl ester phosphate: 3-mercaptopropionic acid: vitamin C: solid phase C = 100:1.4:12:3.6:0.4:0.5:3; the mass ratio of isopentanyl polyoxyethylene ether to deionized water in the mixed solution A is isopentanyl polyoxyethylene ether: water = 100:70; the mass ratio of acrylic acid to deionized water in the mixed solution B is acrylic acid: water = 12:7; the mass ratio of vitamin C to deionized water in the mixed solution C is vitamin C: water = 0.5:90; the mass ratio of the added mass of hydrogen peroxide to the mixed solution A is hydrogen peroxide: mixed solution A = 1.9:100, and the mass percentage of solute in the hydrogen peroxide is 10%; after the dropwise addition is completed, the mixed solution is continued to be stirred at 60±2°C for 2h, and then air-cooled to room temperature to obtain the water reducer.

[0027] Example 3

[0028] A method for preparing a polycarboxylic acid type composite concrete water reducing agent comprises the following steps:

[0029] (1) preparing a mixed aqueous solution of polyethylene glycol and sodium hydroxide; in the mixed aqueous solution of polyethylene glycol and sodium hydroxide, the mass percentage of polyethylene glycol is 20%, the concentration of the sodium hydroxide is 1 mol / L, and the solvent is water; adding carboxymethyl chitosan to the sodium hydroxide solution to obtain a mixture, the mass ratio of carboxymethyl chitosan to the sodium hydroxide solution to obtain the mixture is carboxymethyl chitosan: sodium hydroxide solution = 2:100, the concentration of the solute in the sodium hydroxide solution is 1 mol / L, and the solvent is water; stirring the mixed aqueous solution of polyethylene glycol and sodium hydroxide, adding the mixture to the solution under stirring, and adding the mixture to the mixed aqueous solution of polyethylene glycol and sodium hydroxide The mass ratio of the mixture is: polyethylene glycol: sodium hydroxide The mixed aqueous solution of sodium is 1:8; after the addition is completed, the solution is stirred under ice-water bath conditions for 15 minutes, and then allowed to stand and solidify in a 55°C water bath for 10 minutes, and allowed to stand to complete solid-liquid separation, the solid phase is washed with deionized water, and freeze-dried to obtain dispersed particles; the dispersed particles and grape seed proanthocyanidins are added to deionized water to obtain a mixed solution; the mass ratio of the dispersed particles and grape seed proanthocyanidins added to deionized water is dispersed particles: grape seed proanthocyanidins: deionized water = 7:14:100; the pH value of the mixed solution is adjusted to 4 with dilute hydrochloric acid, the mass percentage of the solute in the dilute hydrochloric acid is 10%, and the solvent is water; the mixed solution is stirred for 10 minutes, and then concentrated under reduced pressure to 1 / 5 of the volume before concentration, solid-liquid separation, and solid-phase freeze-dried to obtain solid phase A;

[0030] (2) adding the solid phase A to deionized water, wherein the mass ratio of the solid phase A to the deionized water is solid phase A: deionized water = 1:20; then adding polyvinylamine; the mass ratio of the added polyvinylamine to the added solid phase A is polyvinylamine: solid phase A = 0.4:1; stirring for 10 minutes after the addition is completed, and then adjusting the pH to 10 with hydrochloric acid or sodium hydroxide solution, wherein the concentration of the solute in the hydrochloric acid is 0.5 mol / L, and the solvent is water; the concentration of the solute in the sodium hydroxide solution is The solvent is 0.5 mol / L, and water is used as the solvent; after the adjustment, an aqueous solution of formaldehyde is added, the mass percentage of formaldehyde in the aqueous solution of formaldehyde is 37%, and the mass ratio of the added volume of the aqueous solution of formaldehyde to the added solid phase A is the aqueous solution of formaldehyde: solid phase A = 0.9 mL: 1 g; after the addition is completed, the water bath is kept at a constant temperature of 65±3°C, and the temperature is kept for 4 hours. During the heat preservation process, condensation reflux is carried out, and after the heat preservation is completed, air cooling is carried out to room temperature, solid-liquid separation is carried out, the solid phase is washed with deionized water, and dried at 60°C for 30 minutes to obtain solid phase B;

[0031] (3) preparing an ethanol solution of pyrophosphoric acid; in the ethanol solution of pyrophosphoric acid, the concentration of pyrophosphoric acid is 8 g / 100 mL, and the solvent is ethanol; adding the solid phase B to ethanol to form an alcohol suspension, the mass ratio of solid phase B to ethanol is solid phase B: ethanol = 1:20; keeping the alcohol suspension at a constant temperature of 70±3° C. in a water bath, stirring the alcohol suspension for 10 min, and then adding KH-550 to the alcohol suspension under stirring. After the addition is completed, the alcohol suspension is stirred at a constant temperature of 70±3° C. for 10 min, and then adding After the addition of deionized water, the alcohol suspension was stirred at a constant temperature of 70±3°C for 3h, and then the ethanol solution of pyrophosphoric acid was added under stirring. After the addition of deionized water, the alcohol suspension was stirred at a constant temperature of 70±3°C for 1h. The mass ratio of the added mass of KH-550, deionized water, and ethanol solution of pyrophosphoric acid to the solid phase B was KH-550: deionized water: ethanol solution of pyrophosphoric acid: solid phase B = 0.7:0.6:4:1; then air-cooled to room temperature, solid-liquid separation, the solid phase was washed with deionized water, and dried at 60°C for 30min to obtain solid phase C;

[0032] (4) Mixing isopentanyl polyoxyethylene ether, ammonium persulfate and deionized water to form a mixed liquid A, mixing acrylic acid, 2-methyl-2-acrylic acid-2-hydroxyethyl ester phosphate and deionized water to form a mixed liquid B, and mixing 3-mercaptopropionic acid, vitamin C and deionized water to form a mixed liquid C; adding the solid phase C to the mixed liquid A, and then stirring in a water bath at a constant temperature of 60±2° C. for 30 minutes, and then dropping the mixed liquid B, mixed liquid C and hydrogen peroxide into the mixed liquid A at the same time under stirring, wherein the mass ratio of the isopentanyl polyoxyethylene ether, ammonium persulfate, acrylic acid, 2-methyl-2-acrylic acid-2-hydroxyethyl ester phosphate, 3-mercaptopropionic acid, vitamin C and solid phase C is isopentanyl polyoxyethylene ether: ammonium persulfate: acrylic acid: 2-methyl-2-acrylic acid -2-hydroxyethyl ester phosphate: 3-mercaptopropionic acid: vitamin C: solid phase C = 100:1.5:12:3.8:0.5:0.5:4; the mass ratio of isopentanyl polyoxyethylene ether to deionized water in the mixed liquid A is isopentanyl polyoxyethylene ether: water = 100:70; the mass ratio of acrylic acid to deionized water in the mixed liquid B is acrylic acid: water = 12:7; the mass ratio of vitamin C to deionized water in the mixed liquid C is vitamin C: water = 0.5:90; the mass ratio of the added mass of hydrogen peroxide to the mixed liquid A is hydrogen peroxide: mixed liquid A = 1.9:100, and the mass percentage of solute in the hydrogen peroxide is 10%; after the dropwise addition is completed, the mixed liquid is continued to be stirred at 60±2°C for 2h, and then air-cooled to room temperature to obtain the water reducer.

[0033] Example 4

[0034] A method for preparing a polycarboxylic acid type composite concrete water reducing agent comprises the following steps:

[0035] (1) preparing a mixed aqueous solution of polyethylene glycol and sodium hydroxide; in the mixed aqueous solution of polyethylene glycol and sodium hydroxide, the mass percentage of polyethylene glycol is 20%, the concentration of the sodium hydroxide is 1 mol / L, and the solvent is water; adding carboxymethyl chitosan to the sodium hydroxide solution to obtain a mixture, the mass ratio of carboxymethyl chitosan to the sodium hydroxide solution to obtain the mixture is carboxymethyl chitosan: sodium hydroxide solution = 2:100, the concentration of the solute in the sodium hydroxide solution is 1 mol / L, and the solvent is water; stirring the mixed aqueous solution of polyethylene glycol and sodium hydroxide, adding the mixture to the solution under stirring, and adding the mixture to the mixed aqueous solution of polyethylene glycol and sodium hydroxide The mass ratio of the mixture is: polyethylene glycol: sodium hydroxide The mixed aqueous solution of sodium is 1:8; after the addition is completed, the solution is stirred under ice-water bath conditions for 15 minutes, and then allowed to stand and solidify in a 55°C water bath for 10 minutes, and allowed to stand to complete solid-liquid separation, the solid phase is washed with deionized water, and freeze-dried to obtain dispersed particles; the dispersed particles and grape seed proanthocyanidins are added to deionized water to obtain a mixed solution; the mass ratio of the dispersed particles and grape seed proanthocyanidins added to deionized water is dispersed particles: grape seed proanthocyanidins: deionized water = 8:15:100; the pH value of the mixed solution is adjusted to 4 with dilute hydrochloric acid, the mass percentage of the solute in the dilute hydrochloric acid is 10%, and the solvent is water; the mixed solution is stirred for 10 minutes, and then concentrated under reduced pressure to 1 / 5 of the volume before concentration, solid-liquid separation, and solid-phase freeze-dried to obtain solid phase A;

[0036] (2) Add the solid phase A to deionized water, the mass ratio of the solid phase A to the deionized water is solid phase A: deionized water = 1:20; then add polyvinylamine; the mass ratio of the added polyvinylamine to the added solid phase A is polyvinylamine: solid phase A = 0.5:1; after the addition is completed, stir for 10 minutes, and then adjust the pH to 10 with hydrochloric acid or sodium hydroxide solution, the solute concentration in the hydrochloric acid is 0.5 mol / L, and the solvent is water; the solute concentration in the sodium hydroxide solution is 0.5 mol / L, and the solvent is water; after the adjustment is completed, add a formaldehyde aqueous solution, the mass percentage of formaldehyde in the formaldehyde aqueous solution is 37%, and the volume of the formaldehyde aqueous solution added to the mass ratio of the added solid phase A is formaldehyde aqueous solution: solid phase A = 1 mL: 1 g; after the addition is completed, keep the water bath constant temperature at 65±3°C, keep the temperature for 4 hours, condense and reflux during the insulation process, air cool to room temperature after the insulation is completed, separate the solid and liquid, wash the solid phase with deionized water, and dry it at 60°C for 30 minutes to obtain a solid phase B;

[0037] (3) preparing an ethanol solution of pyrophosphoric acid; in the ethanol solution of pyrophosphoric acid, the concentration of pyrophosphoric acid is 8 g / 100 mL, and the solvent is ethanol; adding the solid phase B to ethanol to form an alcohol suspension, the mass ratio of solid phase B to ethanol is solid phase B: ethanol = 1:20; keeping the alcohol suspension at a constant temperature of 70±3° C. in a water bath, stirring the alcohol suspension for 10 min, and then adding KH-550 to the alcohol suspension under stirring. After the addition is completed, the alcohol suspension is stirred at a constant temperature of 70±3° C. for 10 min, and then adding After the addition of deionized water, the alcohol suspension was stirred at a constant temperature of 70±3°C for 3h, and then the ethanol solution of pyrophosphoric acid was added under stirring. After the addition of deionized water, the alcohol suspension was stirred at a constant temperature of 70±3°C for 1h. The mass ratio of the added mass of KH-550, deionized water, and ethanol solution of pyrophosphoric acid to the solid phase B was KH-550: deionized water: ethanol solution of pyrophosphoric acid: solid phase B = 0.8:0.6:4:1; then air-cooled to room temperature, solid-liquid separation, the solid phase was washed with deionized water, and dried at 60°C for 30min to obtain solid phase C;

[0038] (4) Mixing isopentanyl polyoxyethylene ether, ammonium persulfate and deionized water to form a mixed liquid A, mixing acrylic acid, 2-methyl-2-acrylic acid-2-hydroxyethyl ester phosphate and deionized water to form a mixed liquid B, and mixing 3-mercaptopropionic acid, vitamin C and deionized water to form a mixed liquid C; adding the solid phase C to the mixed liquid A, and then keeping the temperature in a water bath at 60±2° C. and stirring for 30 minutes, and then dropping the mixed liquid B, mixed liquid C and hydrogen peroxide into the mixed liquid A at the same time under stirring, wherein the mass ratio of the isopentanyl polyoxyethylene ether, ammonium persulfate, acrylic acid, 2-methyl-2-acrylic acid-2-hydroxyethyl ester phosphate, 3-mercaptopropionic acid, vitamin C and solid phase C is isopentanyl polyoxyethylene ether: ammonium persulfate: acrylic acid: 2-methyl-2-acrylic acid Acid-2-hydroxyethyl ester phosphate: 3-mercaptopropionic acid: vitamin C: solid phase C = 100: 1.5: 13: 4.2: 0.5: 0.6: 4; the mass ratio of the mass of isopentanyl polyoxyethylene ether and deionized water in the mixed liquid A is isopentanyl polyoxyethylene ether: water = 100: 70; the mass ratio of the mass of acrylic acid and deionized water in the mixed liquid B is acrylic acid: water = 13: 7; the mass ratio of the mass of vitamin C and deionized water in the mixed liquid C is vitamin C: water = 0.6: 90; the mass ratio of the added mass of hydrogen peroxide to the mixed liquid A is hydrogen peroxide: mixed liquid A = 2: 100, and the mass percentage of the solute in the hydrogen peroxide is 10%; after the dropwise addition is completed, the mixed liquid is continued to be kept stirred at 60 ± 2 ° C for 2 hours, and then air-cooled to room temperature to obtain the water reducing agent.

[0039] Comparative Example 1

[0040] A preparation method of a concrete water reducing agent for comparison comprises the following steps: mixing isopentenyl polyoxyethylene ether, ammonium persulfate and deionized water to form a mixed liquid A, mixing acrylic acid, 2-methyl-2-acrylic acid-2-hydroxyethyl ester phosphate and deionized water to form a mixed liquid B, and mixing 3-mercaptopropionic acid, vitamin C and deionized water to form a mixed liquid C; the mixed liquid A is kept at a constant temperature of 60±2° C. in a water bath and is kept warm and stirred for 30 minutes, and then the mixed liquid B, the mixed liquid C and hydrogen peroxide are simultaneously added dropwise to the mixed liquid A under stirring, wherein the mass ratio of the isopentenyl polyoxyethylene ether, ammonium persulfate, acrylic acid, 2-methyl-2-acrylic acid-2-hydroxyethyl ester phosphate, 3-mercaptopropionic acid and vitamin C is isopentenyl polyoxyethylene ether: ammonium persulfate: acrylic acid: 2-methyl -2-acrylic acid-2-hydroxyethyl ester phosphate: 3-mercaptopropionic acid: vitamin C = 100:1.5:12:3.8:0.5:0.5; the mass ratio of isopentanyl polyoxyethylene ether to deionized water in the mixed liquid A is isopentanyl polyoxyethylene ether: water = 100:70; the mass ratio of acrylic acid to deionized water in the mixed liquid B is acrylic acid: water = 12:7; the mass ratio of vitamin C to deionized water in the mixed liquid C is vitamin C: water = 0.5:90; the mass ratio of the added mass of hydrogen peroxide to the mixed liquid A is hydrogen peroxide: mixed liquid A = 1.9:100, and the mass percentage of solute in the hydrogen peroxide is 10%; after the dropwise addition is completed, the mixed liquid is continued to be stirred at 60±2°C for 2h, and then air-cooled to room temperature to obtain the water reducer.

[0041] Comparative Example 2

[0042] A method for preparing a concrete water reducing agent as a comparison comprises the following steps:

[0043] (1) preparing a mixed aqueous solution of polyethylene glycol and sodium hydroxide; in the mixed aqueous solution of polyethylene glycol and sodium hydroxide, the mass percentage of polyethylene glycol is 20%, the concentration of sodium hydroxide is 1 mol / L, and the solvent is water; adding carboxymethyl chitosan to the sodium hydroxide solution to obtain a mixture, the mass ratio of carboxymethyl chitosan to the sodium hydroxide solution to obtain the mixture is carboxymethyl chitosan: sodium hydroxide solution = 2:100, the concentration of the solute in the sodium hydroxide solution is 1 mol / L, and the solvent is water; stirring the mixed aqueous solution of polyethylene glycol and sodium hydroxide, adding the mixture to the solution under stirring, and adding the mixture to the mixed aqueous solution of polyethylene glycol and sodium hydroxide The mass ratio of the mixture is added to the mixed aqueous solution of polyethylene glycol and sodium hydroxide is a mixture: a mixed aqueous solution of polyethylene glycol and sodium hydroxide = 1:8; after the addition is completed, stirring the solution under ice-water bath conditions for 15 minutes, and then standing in a 55°C water bath for solidification for 10 minutes, standing to complete solid-liquid separation, washing the solid phase with deionized water, and freeze-drying to obtain dispersed particles as the solid phase A of this comparative example;

[0044] (2) adding the solid phase A to deionized water, wherein the mass ratio of the solid phase A to the deionized water is solid phase A: deionized water = 1:20; then adding polyvinylamine; the mass ratio of the added polyvinylamine to the added solid phase A is polyvinylamine: solid phase A = 0.4:1; stirring for 10 minutes after the addition is completed, and then adjusting the pH to 10 with hydrochloric acid or sodium hydroxide solution, wherein the concentration of the solute in the hydrochloric acid is 0.5 mol / L, and the solvent is water; the concentration of the solute in the sodium hydroxide solution is The solvent is 0.5 mol / L, and water is used as the solvent; after the adjustment, an aqueous solution of formaldehyde is added, the mass percentage of formaldehyde in the aqueous solution of formaldehyde is 37%, and the mass ratio of the added volume of the aqueous solution of formaldehyde to the added solid phase A is the aqueous solution of formaldehyde: solid phase A = 0.9 mL: 1 g; after the addition is completed, the water bath is kept at a constant temperature of 65±3°C, and the temperature is kept for 4 hours. During the heat preservation process, condensation reflux is carried out, and after the heat preservation is completed, air cooling is carried out to room temperature, solid-liquid separation is carried out, the solid phase is washed with deionized water, and dried at 60°C for 30 minutes to obtain solid phase B;

[0045] (3) preparing an ethanol solution of pyrophosphoric acid; in the ethanol solution of pyrophosphoric acid, the concentration of pyrophosphoric acid is 8 g / 100 mL, and the solvent is ethanol; adding the solid phase B to ethanol to form an alcohol suspension, the mass ratio of solid phase B to ethanol is solid phase B: ethanol = 1:20; keeping the alcohol suspension at a constant temperature of 70±3° C. in a water bath, stirring the alcohol suspension for 10 min, and then adding KH-550 to the alcohol suspension under stirring. After the addition is completed, the alcohol suspension is stirred at a constant temperature of 70±3° C. for 10 min, and then adding After the addition of deionized water, the alcohol suspension was stirred at a constant temperature of 70±3°C for 3h, and then the ethanol solution of pyrophosphoric acid was added under stirring. After the addition of deionized water, the alcohol suspension was stirred at a constant temperature of 70±3°C for 1h. The mass ratio of the added mass of KH-550, deionized water, and ethanol solution of pyrophosphoric acid to the solid phase B was KH-550: deionized water: ethanol solution of pyrophosphoric acid: solid phase B = 0.7:0.6:4:1; then air-cooled to room temperature, solid-liquid separation, the solid phase was washed with deionized water, and dried at 60°C for 30min to obtain solid phase C;

[0046] (4) Mixing isopentanyl polyoxyethylene ether, ammonium persulfate and deionized water to form a mixed liquid A, mixing acrylic acid, 2-methyl-2-acrylic acid-2-hydroxyethyl ester phosphate and deionized water to form a mixed liquid B, and mixing 3-mercaptopropionic acid, vitamin C and deionized water to form a mixed liquid C; adding the solid phase C to the mixed liquid A, and then stirring in a water bath at a constant temperature of 60±2° C. for 30 minutes, and then dropping the mixed liquid B, mixed liquid C and hydrogen peroxide into the mixed liquid A at the same time under stirring, wherein the mass ratio of the isopentanyl polyoxyethylene ether, ammonium persulfate, acrylic acid, 2-methyl-2-acrylic acid-2-hydroxyethyl ester phosphate, 3-mercaptopropionic acid, vitamin C and solid phase C is isopentanyl polyoxyethylene ether: ammonium persulfate: acrylic acid: 2-methyl-2-acrylic acid -2-hydroxyethyl ester phosphate: 3-mercaptopropionic acid: vitamin C: solid phase C = 100:1.5:12:3.8:0.5:0.5:4; the mass ratio of isopentanyl polyoxyethylene ether to deionized water in the mixed liquid A is isopentanyl polyoxyethylene ether: water = 100:70; the mass ratio of acrylic acid to deionized water in the mixed liquid B is acrylic acid: water = 12:7; the mass ratio of vitamin C to deionized water in the mixed liquid C is vitamin C: water = 0.5:90; the mass ratio of the added mass of hydrogen peroxide to the mixed liquid A is hydrogen peroxide: mixed liquid A = 1.9:100, and the mass percentage of solute in the hydrogen peroxide is 10%; after the dropwise addition is completed, the mixed liquid is continued to be stirred at 60±2°C for 2h, and then air-cooled to room temperature to obtain the water reducer.

[0047] Comparative Example 3

[0048] A method for preparing a concrete water reducing agent as a comparison comprises the following steps:

[0049] (1) preparing a mixed aqueous solution of polyethylene glycol and sodium hydroxide; in the mixed aqueous solution of polyethylene glycol and sodium hydroxide, the mass percentage of polyethylene glycol is 20%, the concentration of the sodium hydroxide is 1 mol / L, and the solvent is water; adding carboxymethyl chitosan to the sodium hydroxide solution to obtain a mixture, the mass ratio of carboxymethyl chitosan to the sodium hydroxide solution to obtain the mixture is carboxymethyl chitosan: sodium hydroxide solution = 2:100, the concentration of the solute in the sodium hydroxide solution is 1 mol / L, and the solvent is water; stirring the mixed aqueous solution of polyethylene glycol and sodium hydroxide, adding the mixture to the solution under stirring, and adding the mixture to the mixed aqueous solution of polyethylene glycol and sodium hydroxide The mass ratio of the mixture is: polyethylene glycol: sodium hydroxide The mixed aqueous solution of sodium is 1:8; after the addition is completed, the solution is stirred under ice-water bath conditions for 15 minutes, and then allowed to stand and solidify in a 55°C water bath for 10 minutes, and allowed to stand to complete solid-liquid separation, the solid phase is washed with deionized water, and freeze-dried to obtain dispersed particles; the dispersed particles and grape seed proanthocyanidins are added to deionized water to obtain a mixed solution; the mass ratio of the dispersed particles and grape seed proanthocyanidins added to deionized water is dispersed particles: grape seed proanthocyanidins: deionized water = 7:14:100; the pH value of the mixed solution is adjusted to 4 with dilute hydrochloric acid, the mass percentage of the solute in the dilute hydrochloric acid is 10%, and the solvent is water; the mixed solution is stirred for 10 minutes, and then concentrated under reduced pressure to 1 / 5 of the volume before concentration, solid-liquid separation, and solid-phase freeze-dried to obtain solid phase A;

[0050] (2) preparing an ethanol solution of pyrophosphoric acid; in the ethanol solution of pyrophosphoric acid, the concentration of pyrophosphoric acid is 8 g / 100 mL, and the solvent is ethanol; adding the solid phase A to ethanol to form an alcohol suspension, the mass ratio of solid phase A to ethanol is solid phase A: ethanol = 1:20; keeping the alcohol suspension in a water bath at a constant temperature of 70±3° C., stirring the alcohol suspension for 10 min, and then adding KH-550 to the alcohol suspension under stirring. After the addition is completed, the alcohol suspension is stirred at a constant temperature of 70±3° C. for 10 min, and then adding deionized water under stirring. After the addition is completed, the alcohol suspension is stirred at a constant temperature of 70±3°C for 3h, and then the ethanol solution of pyrophosphoric acid is added under stirring. After the addition is completed, the alcohol suspension is stirred at a constant temperature of 70±3°C for 1h. The mass ratio of the added mass of KH-550, deionized water, and ethanol solution of pyrophosphoric acid to the solid phase A is KH-550: deionized water: ethanol solution of pyrophosphoric acid: solid phase A = 0.7:0.6:4:1; then air-cooled to room temperature, solid-liquid separation, the solid phase is washed with deionized water, and dried at 60°C for 30min to obtain the solid phase C of this comparative example;

[0051] (3) Mixing isopentanyl polyoxyethylene ether, ammonium persulfate and deionized water to form a mixed liquid A, mixing acrylic acid, 2-methyl-2-acrylic acid-2-hydroxyethyl ester phosphate and deionized water to form a mixed liquid B, and mixing 3-mercaptopropionic acid, vitamin C and deionized water to form a mixed liquid C; adding the solid phase C to the mixed liquid A, and then stirring in a water bath at a constant temperature of 60±2° C. for 30 minutes, and then dropping the mixed liquid B, mixed liquid C and hydrogen peroxide into the mixed liquid A at the same time under stirring, wherein the mass ratio of the isopentanyl polyoxyethylene ether, ammonium persulfate, acrylic acid, 2-methyl-2-acrylic acid-2-hydroxyethyl ester phosphate, 3-mercaptopropionic acid, vitamin C and solid phase C is isopentanyl polyoxyethylene ether: ammonium persulfate: acrylic acid: 2-methyl-2-acrylic acid -2-hydroxyethyl ester phosphate: 3-mercaptopropionic acid: vitamin C: solid phase C = 100:1.5:12:3.8:0.5:0.5:4; the mass ratio of isopentanyl polyoxyethylene ether to deionized water in the mixed liquid A is isopentanyl polyoxyethylene ether: water = 100:70; the mass ratio of acrylic acid to deionized water in the mixed liquid B is acrylic acid: water = 12:7; the mass ratio of vitamin C to deionized water in the mixed liquid C is vitamin C: water = 0.5:90; the mass ratio of the added mass of hydrogen peroxide to the mixed liquid A is hydrogen peroxide: mixed liquid A = 1.9:100, and the mass percentage of solute in the hydrogen peroxide is 10%; after the dropwise addition is completed, the mixed liquid is continued to be stirred at 60±2°C for 2h, and then air-cooled to room temperature to obtain the water reducer.

[0052] Comparative Example 4

[0053] A method for preparing a concrete water reducing agent as a comparison comprises the following steps:

[0054] (1) preparing a mixed aqueous solution of polyethylene glycol and sodium hydroxide; in the mixed aqueous solution of polyethylene glycol and sodium hydroxide, the mass percentage of polyethylene glycol is 20%, the concentration of the sodium hydroxide is 1 mol / L, and the solvent is water; adding carboxymethyl chitosan to the sodium hydroxide solution to obtain a mixture, the mass ratio of carboxymethyl chitosan to the sodium hydroxide solution to obtain the mixture is carboxymethyl chitosan: sodium hydroxide solution = 2:100, the concentration of the solute in the sodium hydroxide solution is 1 mol / L, and the solvent is water; stirring the mixed aqueous solution of polyethylene glycol and sodium hydroxide, adding the mixture to the solution under stirring, and adding the mixture to the mixed aqueous solution of polyethylene glycol and sodium hydroxide The mass ratio of the mixture is: polyethylene glycol: sodium hydroxide The mixed aqueous solution of sodium is 1:8; after the addition is completed, the solution is stirred under ice-water bath conditions for 15 minutes, and then allowed to stand and solidify in a 55°C water bath for 10 minutes, and allowed to stand to complete solid-liquid separation, the solid phase is washed with deionized water, and freeze-dried to obtain dispersed particles; the dispersed particles and grape seed proanthocyanidins are added to deionized water to obtain a mixed solution; the mass ratio of the dispersed particles and grape seed proanthocyanidins added to deionized water is dispersed particles: grape seed proanthocyanidins: deionized water = 7:14:100; the pH value of the mixed solution is adjusted to 4 with dilute hydrochloric acid, the mass percentage of the solute in the dilute hydrochloric acid is 10%, and the solvent is water; the mixed solution is stirred for 10 minutes, and then concentrated under reduced pressure to 1 / 5 of the volume before concentration, solid-liquid separation, and solid-phase freeze-dried to obtain solid phase A;

[0055] (2) adding the solid phase A to deionized water, wherein the mass ratio of the solid phase A to the deionized water is solid phase A: deionized water = 1:20; then adding polyvinylamine; the mass ratio of the added polyvinylamine to the added solid phase A is polyvinylamine: solid phase A = 0.4:1; stirring for 10 minutes after the addition is completed, and then adjusting the pH to 10 with hydrochloric acid or sodium hydroxide solution, wherein the concentration of the solute in the hydrochloric acid is 0.5 mol / L, and the solvent is water; the concentration of the solute in the sodium hydroxide solution is The solvent is 0.5 mol / L, and water is used as the solvent; after the adjustment, an aqueous solution of formaldehyde is added, the mass percentage of formaldehyde in the aqueous solution of formaldehyde is 37%, and the mass ratio of the added volume of the aqueous solution of formaldehyde to the added solid phase A is the aqueous solution of formaldehyde: solid phase A = 0.9 mL: 1 g; after the addition is completed, the water bath is kept at a constant temperature of 65±3°C, and the temperature is kept for 4 hours. During the heat preservation process, condensation reflux is carried out, and after the heat preservation is completed, air cooling is carried out to room temperature, solid-liquid separation is carried out, the solid phase is washed with deionized water, and dried at 60°C for 30 minutes to obtain solid phase B;

[0056] (3) Mixing isopentanyl polyoxyethylene ether, ammonium persulfate and deionized water to form a mixed liquid A, mixing acrylic acid, 2-methyl-2-acrylic acid-2-hydroxyethyl ester phosphate and deionized water to form a mixed liquid B, and mixing 3-mercaptopropionic acid, vitamin C and deionized water to form a mixed liquid C; adding the solid phase B to the mixed liquid A, and then stirring in a water bath at a constant temperature of 60±2° C. for 30 minutes, and then dropping the mixed liquid B, mixed liquid C and hydrogen peroxide into the mixed liquid A at the same time under stirring, wherein the mass ratio of the isopentanyl polyoxyethylene ether, ammonium persulfate, acrylic acid, 2-methyl-2-acrylic acid-2-hydroxyethyl ester phosphate, 3-mercaptopropionic acid, vitamin C and solid phase B is isopentanyl polyoxyethylene ether: ammonium persulfate: acrylic acid: 2-methyl-2-acrylic acid -2-hydroxyethyl ester phosphate: 3-mercaptopropionic acid: vitamin C: solid phase B = 100:1.5:12:3.8:0.5:0.5:4; the mass ratio of isopentanyl polyoxyethylene ether to deionized water in the mixed liquid A is isopentanyl polyoxyethylene ether: water = 100:70; the mass ratio of acrylic acid to deionized water in the mixed liquid B is acrylic acid: water = 12:7; the mass ratio of vitamin C to deionized water in the mixed liquid C is vitamin C: water = 0.5:90; the mass ratio of the added mass of hydrogen peroxide to the mixed liquid A is hydrogen peroxide: mixed liquid A = 1.9:100, and the mass percentage of solute in the hydrogen peroxide is 10%; after the dropwise addition is completed, the mixed liquid is continued to be stirred at 60±2°C for 2h, and then air-cooled to room temperature to obtain the water reducer.

[0057] Example 5

[0058] The water reducing rate of the water reducing agent prepared by the methods described in the above embodiments and comparative examples was tested according to the requirements of standard GB / T8076-2008. The proportion of the test concrete (including the water reducing agent) was: cement (Gaoan Hongshi ordinary Portland cement P.O42.5) 360kg / m 3 , sand 860kg / m 3 , water 200kg / m 3 , crushed stone (5~10mm 420kg / m 3 , 10~20mm 600kg / m 3 ), the amount of water reducing agent added was 0.8% of the total mass of concrete, and the slump of concrete in each test group was 180±10mm; the concrete without water reducing agent was the blank group. The 28d compressive strength of the above test concrete and the blank group was tested in accordance with the requirements of standard GB / T50081-2019, and the results are shown in Table 1.

[0059] Table 1

[0060] Experimental Group Slump / mm Water reduction rate / % 28d compressive strength / MPa Example 1 185 29.2 50.8 Example 2 183 29.5 52.4 Example 3 180 29.8 53.2 Example 4 178 29.7 52.7 Comparative Example 1 184 21.4 38.1 Comparative Example 2 180 24.7 44.0 Comparative Example 3 186 26.0 45.5 Comparative Example 4 182 25.6 42.9 Blank group 179 / 33.5

[0061] As shown in Table 1, the water reducing agent prepared by the method of the present invention has a high water reducing rate and can significantly improve the compressive strength of concrete. This may be because the admixture prepared by the present invention has a large number of active functional groups on its surface, which can form a dense network structure with cement and hydration products in concrete, thereby improving the compressive strength. The prepared solid phase C can fill the pores of the network structure, improve the overall density of the material, and further improve the strength of the material.

[0062] The technical solution provided by the present invention is introduced in detail above. For those skilled in the art, according to the concept of the embodiments of the present invention, there may be changes in the specific implementation method and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A method for preparing a polycarboxylic acid type composite concrete water reducing agent, characterized in that: The following steps are included: (1) preparing a mixed aqueous solution of polyethylene glycol and sodium hydroxide; adding carboxymethyl chitosan to the sodium hydroxide solution to obtain a mixture, stirring the mixed aqueous solution of polyethylene glycol and sodium hydroxide, adding the mixture to the solution under stirring, stirring the solution in an ice-water bath for 15 to 18 minutes after the addition is completed, and then standing in a 55° C. water bath for solidification for 10 to 15 minutes, standing to complete solid-liquid separation, washing the solid phase with deionized water, and freeze-drying to obtain dispersed particles; adding the dispersed particles and grape seed proanthocyanidins to deionized water to obtain a mixed solution; adjusting the pH value of the mixed solution to 4 with dilute hydrochloric acid, stirring the mixed solution for more than 10 minutes, and then concentrating under reduced pressure, separating the solid and liquid, and freeze-drying the solid phase to obtain a solid phase A; (2) adding the solid phase A to deionized water, and then adding polyethylene amine; stirring for more than 10 minutes after the addition is completed, and then adjusting the pH to 10 with hydrochloric acid or sodium hydroxide solution, adding a formaldehyde aqueous solution after the adjustment is completed, and keeping the water bath constant at 65±3° C. after the addition is completed, and keeping the temperature for more than 4 hours, condensing and reflux during the insulation process, and air cooling to room temperature after the insulation is completed, solid-liquid separation, washing the solid phase with deionized water, and drying at 60° C. for more than 30 minutes to obtain a solid phase B; (3) preparing an ethanol solution of pyrophosphoric acid; adding the solid phase B to ethanol to form an alcohol suspension, keeping the alcohol suspension constant temperature at 70±3°C in a water bath, stirring the alcohol suspension for more than 10 minutes, then adding KH-550 to the alcohol suspension under stirring, stirring the alcohol suspension at 70±3°C for more than 10 minutes after the addition is completed, then adding deionized water under stirring, stirring the alcohol suspension at 70±3°C for more than 3 hours after the addition is completed, then adding the ethanol solution of pyrophosphoric acid under stirring, stirring the alcohol suspension at 70±3°C for more than 1 hour after the addition is completed, then air cooling to room temperature, solid-liquid separation, washing the solid phase with deionized water, and drying at 60°C for more than 30 minutes to obtain a solid phase C; (4) Mixing isopentyl polyoxyethylene ether, ammonium persulfate and deionized water to form a mixed solution A, mixing acrylic acid, 2-methyl-2-acrylic acid-2-hydroxyethyl phosphate and deionized water to form a mixed solution B, and mixing 3-mercaptopropionic acid, vitamin C and deionized water to form a mixed solution C; adding the solid phase C to the mixed solution A, and then keeping the temperature at 60±2° C. in a water bath and stirring for more than 30 minutes, and then dropping the mixed solution B, mixed solution C and hydrogen peroxide into the mixed solution A while stirring, and after the dropping is completed, continue to keep the temperature at 60±2° C. and stir the mixed solution for more than 2 hours, and then air cool to room temperature to obtain the water reducing agent.

2. The method for preparing a polycarboxylic acid type composite concrete water reducing agent according to claim 1, characterized in that: In the step (1), in the mixed aqueous solution of polyethylene glycol and sodium hydroxide, the mass percentage of polyethylene glycol is 20% to 22%, the concentration of the sodium hydroxide is 1 mol / L, and the solvent is water; carboxymethyl chitosan is added to the sodium hydroxide solution to obtain a mixture with a mass ratio of carboxymethyl chitosan: sodium hydroxide solution = 2:100, the concentration of the solute in the sodium hydroxide solution is 1 mol / L, and the solvent is water; the mass ratio of adding the mixture to the mixed aqueous solution of polyethylene glycol and sodium hydroxide is the mixture: the mixed aqueous solution of polyethylene glycol and sodium hydroxide = 1:

8.

3. The method for preparing a polycarboxylic acid type composite concrete water reducing agent according to claim 1, characterized in that: In the step (1), the mass ratio of the dispersed particles and grape seed proanthocyanidins added to deionized water is dispersed particles: grape seed proanthocyanidins: deionized water = 6-8:10-15:100; the mass percentage of the solute in the dilute hydrochloric acid is 10%, and the solvent is water.

4. The method for preparing a polycarboxylic acid type composite concrete water reducing agent according to claim 1, characterized in that: In the step (2), the mass ratio of the solid phase A added to the deionized water is solid phase A: deionized water = 1:20; the mass ratio of the added polyvinylamine to the mass ratio of the added solid phase A is polyvinylamine: solid phase A = 0.3-0.5:1; the concentration of the solute in the hydrochloric acid is 0.5 mol / L, and the solvent is water; the concentration of the solute in the sodium hydroxide solution is 0.5 mol / L, and the solvent is water; the mass percentage of formaldehyde in the formaldehyde aqueous solution is 37%, and the mass ratio of the added volume of the formaldehyde aqueous solution to the added solid phase A is formaldehyde aqueous solution: solid phase A = 0.8-1 mL: 1 g.

5. The method for preparing a polycarboxylic acid type composite concrete water reducing agent according to claim 1, characterized in that: In the step (3), the concentration of pyrophosphoric acid in the ethanol solution of pyrophosphoric acid is 7-8 g / 100 mL, and the solvent is ethanol; the mass ratio of solid phase B added to ethanol is solid phase B:ethanol=1:20; the mass ratio of KH-550, deionized water, and ethanol solution of pyrophosphoric acid added to solid phase B is KH-550:deionized water:ethanol solution of pyrophosphoric acid:solid phase B=0.6-0.8:0.5-0.6:3-4:

1.

6. The method for preparing a polycarboxylic acid type composite concrete water reducing agent according to claim 1, characterized in that: In the step (4), the mass ratio of the raw materials of isopentenyl polyoxyethylene ether, ammonium persulfate, acrylic acid, 2-methyl-2-acrylic acid-2-hydroxyethyl phosphate, 3-mercaptopropionic acid, vitamin C, and solid phase C is isopentenyl polyoxyethylene ether: ammonium persulfate: acrylic acid: 2-methyl-2-acrylic acid-2-hydroxyethyl phosphate: 3-mercaptopropionic acid: vitamin C: solid phase C = 100: 1.4-1.5: 11-13: 3.2-4.2: 0.4-0.5: 0.4-0.6: 3-4; The mass ratio of the mass of isopentenyl polyoxyethylene ether to deionized water in the mixed liquid A is isopentenyl polyoxyethylene ether: water = 100:70; the mass ratio of the mass of acrylic acid to deionized water in the mixed liquid B is acrylic acid: water = 11-13:7; the mass ratio of the mass of vitamin C to deionized water in the mixed liquid C is vitamin C: water = 0.4-0.6:90; the mass ratio of the added mass of hydrogen peroxide to the mixed liquid A is hydrogen peroxide: mixed liquid A = 1.8-2:100, and the mass percentage of solutes in the hydrogen peroxide is 10%.