A novel polycarboxylate water reducer and preparation method thereof

Abstract

The present invention relates to a novel polycarboxylate water-reducer and a preparation method thereof, wherein the novel polycarboxylate water-reducer is generated by polymerization reaction of compound A, compound B, unsaturated macromonomer, unsaturated carboxylic acid and / or unsaturated carboxylic acid anhydride under the action of an initiator and a molecular weight regulator; the mass ratio of the unsaturated macromonomer, compound A, compound B, unsaturated carboxylic acid and / or unsaturated carboxylic acid anhydride is 180:(1-5):(1-10):(5-30). The present invention introduces compound A into the molecular structure of the polycarboxylate water-reducer through copolymerization reaction, so that the main chain side group has a benzene ring and a carboxyl group or a sulfonic acid group, and the carboxyl group or the sulfonic acid group provides electrostatic repulsion, thereby enhancing the water-reducing effect; the benzene ring makes the obtained polycarboxylate water-reducer molecule more stretched after being adsorbed on the surface of cement particles, and the steric hindrance effect is more obvious, and finally the water-reducing rate of the product is also higher.

Description

Technical Field

[0001] The invention relates to the field of admixtures, and in particular to a novel polycarboxylate water reducer and a preparation method thereof. Background Art

[0002] Polycarboxylate water reducer has the characteristics of high water reduction rate, strong performance designability, and convenient production. In addition, polycarboxylate water reducer does not produce harmful substances such as formaldehyde and ammonia during the synthesis process, and the synthesis temperature is much lower than that of naphthalene water reducer. Due to the energy-saving and environmentally friendly production process of polycarboxylate water reducer, it has been vigorously promoted and applied in the past decade or so, and has become a mainstream product in the water reducer market, widely used in engineering fields such as roads, railways, bridges, nuclear power, dams, tunnels, marine engineering and high-rise buildings.

[0003] The problem of insufficient water reduction rate of polycarboxylate water reducer applied to concrete is becoming increasingly prominent. Therefore, it is necessary to continuously improve the structure of polycarboxylate water reducer to make it have higher water reduction performance, which is the development direction of the polycarboxylate water reducer industry. Summary of the invention

[0004] In view of the prior art, the present invention develops a novel polycarboxylate water reducer and a preparation method thereof, which can use a relatively convenient process method to prepare a high-performance polycarboxylate water reducer with excellent water-reducing effect.

[0005] Based on this, the present invention provides a novel polycarboxylic acid water reducer, which is produced by a polymerization reaction of compound A, compound B, unsaturated macromonomer, unsaturated carboxylic acid and / or unsaturated carboxylic acid anhydride under the action of an initiator and a molecular weight regulator;

[0006] The structural formula of the compound A is as follows:

[0007]

[0008] Wherein, R1 is an alkylene group with 0-4 carbon atoms, R2 is COOM or SO3M or PO3M2, and M is H or an alkylene group with 0-4 carbon atoms or Na, K, or NH4;

[0009] The structural formula of the compound B is as follows:

[0010]

[0011] Among them, R3 is H or CH3, R4 is an alkylene group with 0-4 carbon atoms, X is O or S, R5 is an alkylene group with 0-4 carbon atoms, R6 is an alkylene group with 0-4 carbon atoms, R7 is COOM or SO3M or PO3M2 or SO2NH2, and M is H or an alkylene group with 0-4 carbon atoms or Na, K, or NH4.

[0012] Furthermore, the mass ratio of the unsaturated macromonomer, compound A, compound B, unsaturated carboxylic acid and / or unsaturated carboxylic acid anhydride is 180:(1-5):(1-10):(5-30).

[0013] Further, the compound A is at least one of (4-vinylphenyl)methanesulfonic acid, sodium (4-vinylphenyl)methanesulfonate, 4-vinylphenylacetic acid, 4-vinylbenzoic acid, 2-methyl-2-(4-vinylphenyl)propionic acid, 4-vinyl-benzoic acid methyl ester, 4-vinyl-benzoic acid ethyl ester, 4-vinylphenylethyl ester, and 4-vinylphenyl diethyl phosphate.

[0014] Further, the compound B is at least one of 4-vinyloxybenzenesulfonic acid, 4-vinyloxybenzoic acid, 4-vinyloxyphenylacetic acid, sodium 4-vinyloxybenzenesulfonate, potassium 4-vinyloxybenzenesulfonate, methyl 4-vinyloxybenzoate, ethyl 4-vinyloxybenzoate, methyl 4-vinyloxyphenylacetate, ethyl 4-vinyloxyphenylacetate, 4-(allyloxy)benzenesulfonamide, 4-(vinyloxy)benzenesulfonamide, 2-(vinyloxy)benzenesulfonamide, and 4-(allyloxy)benzoic acid.

[0015] Furthermore, the molecular weight of the unsaturated macromonomer is 600-6000, and the unsaturated macromonomer is at least one of 3-methyl-3-butene-1-polyethylene glycol, 2-methylallyl polyethylene glycol, ethylene glycol monovinyl polyethylene glycol ether, 4-hydroxybutyl vinyl polyoxyethylene ether, methoxy polyethylene glycol methacrylate, and methoxy polyethylene glycol acrylate.

[0016] Furthermore, the unsaturated carboxylic acid and / or unsaturated carboxylic anhydride is at least one of acrylic acid, methacrylic acid and maleic anhydride.

[0017] Furthermore, the amount of the initiator is 0.5-3.0% of the total mass of the reactants; the amount of the molecular weight regulator is 0.2-3.0% of the total mass of the reactants.

[0018] Furthermore, the initiator includes a water-soluble redox initiator system or a water-soluble peroxide initiator system reagent.

[0019] Furthermore, the initiator is at least one of hydrogen peroxide-ascorbic acid, hydrogen peroxide-bleaching powder, hydrogen peroxide-ascorbic acid-ferrous sulfate, hydrogen peroxide-bleaching powder-ferrous sulfate, hydrogen peroxide-BRUGGOLITE E51-ferrous sulfate, and ammonium persulfate.

[0020] Furthermore, the molecular weight regulator includes at least one of thioglycolic acid, mercaptoethanol, mercaptopropionic acid, sulfonated mercaptopropionic acid, and sodium hypophosphite.

[0021] Another object of the present invention is to provide a method for preparing the novel polycarboxylate water-reducing agent, comprising at least the following steps:

[0022] The unsaturated macromonomer, compound A, compound B and water are added to the reactor and stirred. After the materials are evenly mixed, unsaturated carboxylic acid and / or unsaturated carboxylic anhydride, initiator and molecular weight regulator are added dropwise. The dropping time is 0.5-2h, the initial reaction temperature is 10-25°C, and the material temperature is controlled at 10-30°C during the dropping process; after the dropping is completed, the temperature is kept for 0.5-1h to obtain a copolymer product; in the copolymer product, a base is added to adjust the pH value of the product to 5-7 or no base is added to adjust the pH value, so as to obtain the novel polycarboxylate water reducer.

[0023] In summary, the present invention has the following beneficial effects:

[0024] 1. The present invention introduces compound A into the molecular structure of the polycarboxylate water-reducing agent through copolymerization, so that the main chain side groups have benzene rings and carboxyl groups or sulfonic acid groups. The carboxyl groups or sulfonic acid groups provide electrostatic repulsion and enhance the water-reducing effect. The benzene ring makes the side chains of the obtained polycarboxylate water-reducing agent molecules more stretched after being adsorbed on the surface of cement particles, and the steric hindrance effect is more obvious, which ultimately makes the water-reducing rate of the product higher.

[0025] 2. This application also uses other different types of macromonomers to match different types of small monomers, which is more conducive to copolymerization and also makes the performance of the final product better.

[0026] 3. The raw materials used in the present invention are widely available and the preparation process is simple, so that the prepared product is more in line with the application requirements of polycarboxylic acid water reducer. DETAILED DESCRIPTION

[0027] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0028] The experimental methods in the following examples are conventional methods unless otherwise specified. The experimental materials and reagents used in the following examples are all commercially available unless otherwise specified. The quantitative tests in the following examples were performed in triplicate, and the data are the average or average ± standard deviation of the triplicate experiments.

[0029] In addition, the "and / or" in the full text includes three solutions. Taking A and / or B as an example, it includes technical solution A, technical solution B, and a technical solution that satisfies both A and B. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the fact that ordinary technicians in the field can implement it. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the protection scope required by the present invention. Example 1

[0030] (1) 180.00 g of 3000 molecular weight ethylene glycol monovinyl polyethylene glycol ether, 2.00 g of sodium (4-vinylphenyl) methanesulfonate, 4.00 g of 4-vinyloxybenzenesulfonic acid, 0.006 g of ferrous sulfate and 145.00 g of water were added to a reactor, and the agitator and temperature control device were turned on. After the materials were mixed evenly, an acrylic acid aqueous solution (including 17.00 g of acrylic acid and 20.00 g of water), a hydrogen peroxide aqueous solution (including 1.50 g of hydrogen peroxide and 20.00 g of water), a mercaptopropionic acid aqueous solution (including 0.70 g of mercaptopropionic acid and 20.00 g of water), and a BRUGGOLITE E51 aqueous solution (including BRUGGOLITE E51 0.25g, water 20.00g), the initial reaction temperature is 15°C, the dropping time is 1.0h, the material temperature is controlled to be ≤30°C during the dropping process, and the temperature is kept for 1h after the dropping is completed to obtain a copolymer product;

[0031] (2) Add 7 g of 32% sodium hydroxide aqueous solution to the copolymer product obtained in step (1) to obtain the novel polycarboxylic acid water reducer KZJ-1. Example 2

[0032] (1) 180.00 g of 4-hydroxybutyl vinyl polyoxyethylene ether with a molecular weight of 3000, 6.00 g of 4-vinylbenzoic acid, 2.00 g of 4-(vinyloxy)benzenesulfonamide, 0.005 g of ferrous sulfate and 145.00 g of water were added to a reactor, and the agitator and temperature control device were turned on. After the materials were evenly mixed, an acrylic acid aqueous solution (including 18.00 g of acrylic acid and 20.00 g of water), a hydrogen peroxide aqueous solution (including 1.30 g of hydrogen peroxide and 20.00 g of water), a thioglycolic acid aqueous solution (including 0.90 g of thioglycolic acid and 20.00 g of water), and a bleaching agent aqueous solution (including 0.30 bleaching agent and 20.00 g of water) were added dropwise. The initial reaction temperature was 13° C., the dropping time was 0.75 h, and the material temperature was controlled to be ≤25° C. During the dropping process, the temperature was kept at 1 h after the dropping was completed to obtain a copolymer product.

[0033] (2) Add 9 g of 32% sodium hydroxide aqueous solution to the copolymer product obtained in step (1) to obtain the novel polycarboxylic acid water reducer KZJ-2. Example 3

[0034] (1) 180.00 g of ethylene glycol monovinyl polyglycol ether with a molecular weight of 2400, 1.00 g of 4-vinylphenyl diethyl phosphate, 1.50 g of 2-methyl-2-(4-vinylphenyl) propionic acid, 4.00 g of 4-(allyloxy)benzoic acid, 2.50g sodium hypophosphite, 0.005g ferrous sulfate and 145.00g water were added to the reactor, and the stirrer and temperature control device were turned on. After the materials were evenly mixed, acrylic acid and maleic anhydride mixed aqueous solution (including 14.00g acrylic acid, 2.00g maleic anhydride and 20.00g water), hydrogen peroxide aqueous solution (including 1.50g hydrogen peroxide and 20.00g water) and ascorbic acid aqueous solution (including 0.40 ascorbic acid and 20.00g water) were added dropwise. The initial reaction temperature was 12°C, the dropping time was 1h, and the material temperature was controlled to be ≤30°C during the dropping process. After the dropping was completed, the mixture was kept warm for 1h to obtain a copolymer product.

[0035] (2) Add 10 g of 32% sodium hydroxide aqueous solution to the copolymer product obtained in step (1) to obtain the novel polycarboxylic acid water reducer KZJ-3. Example 4

[0036] (1) 120.00 g of ethylene glycol monovinyl polyethylene glycol ether with a molecular weight of 3000, 60.00 g of 2-methylallyl polyethylene glycol with a molecular weight of 2400, 1.50 g of (4-vinylphenyl) methanesulfonic acid, 1.50 g of 4-vinyl-ethyl benzoate, 2.00 g of 4-vinyloxybenzenesulfonic acid, 3.00 g of 4-(allyloxy)benzoic acid, 3.00 g of sodium hypophosphite, 0.004 g of ferrous sulfate and 145.00 g of water were added to a reactor, and the agitator and temperature control device were turned on. After the materials were mixed evenly, acrylic acid mixed aqueous solution (including 15.00 g of acrylic acid and 20.00 g of water), hydrogen peroxide aqueous solution (including 1.20 g of hydrogen peroxide and 20.00 g of water), BRUGGOLITE E51 aqueous solution (including BRUGGOLITE E51 0.28g, water 20.00g), the initial reaction temperature is 18°C, the dropping time is 1.5h, the material temperature is controlled to be ≤30°C during the dropping process, and the temperature is kept for 0.5h after the dropping is completed to obtain a copolymer product;

[0037] (2) Add 6 g of 32% sodium hydroxide aqueous solution to the copolymer product obtained in step (1) to obtain the novel polycarboxylic acid water reducer KZJ-4. Example 5

[0038] (1) 140.00 g of ethylene glycol monovinyl polyethylene glycol ether with a molecular weight of 3000, 40.00 g of 3-methyl-3-butene-1-polyethylene glycol with a molecular weight of 2400, 2.40 g of (4-vinylphenyl) methanesulfonic acid, 2.00 g of 4-(allyloxy)benzoic acid, 2.00g 4-(allyloxy)benzenesulfonamide, 0.004g ferrous sulfate and 145.00g water were added to the reactor, and the stirrer and temperature control device were turned on. After the materials were evenly mixed, an acrylic acid aqueous solution (including 20.00g acrylic acid and 20.00g water), a hydrogen peroxide aqueous solution (including 1.50g hydrogen peroxide and 20.00g water), a mercaptopropionic acid aqueous solution (including 0.70g mercaptoethanol and 20.00g water), and an ascorbic acid aqueous solution (including 0.40 ascorbic acid and 20.00g water) were added dropwise. The initial reaction temperature was 15°C, the dropping time was 1.0h, and the material temperature was controlled to be ≤25°C during the dropping process. After the dropping was completed, the mixture was kept warm for 0.5h to obtain a copolymer product.

[0039] (2) 11 g of 32% sodium hydroxide aqueous solution was added to the copolymerization product obtained in step (1) to obtain the novel polycarboxylic acid water reducer, which was recorded as KZJ-5.

[0040] Comparative Example 1

[0041] (1) 180.00 g of ethylene glycol monovinyl polyglycol ether with a molecular weight of 3000, 4.00 g of 4-vinyloxybenzenesulfonic acid, 0.006 g of ferrous sulfate and 145.00 g of water were added to a reactor, and the stirrer and temperature control device were turned on. After the materials were evenly mixed, an acrylic acid aqueous solution (including 17.00 g of acrylic acid and 20.00 g of water), a hydrogen peroxide aqueous solution (including 1.50 g of hydrogen peroxide and 20.00 g of water), a mercaptopropionic acid aqueous solution (including 0.70 g of mercaptopropionic acid and 20.00 g of water), and a BRUGGOLITE E51 aqueous solution (including 0.25 g of BRUGGOLITE E51 and 20.00 g of water) were added dropwise. The initial reaction temperature was 15° C. The dropping time was 1.0 h. The material temperature was controlled to be ≤30° C. After the dropping was completed, the mixture was kept warm for 1 h to obtain a copolymer product.

[0042] (2) Add 7 g of 32% sodium hydroxide aqueous solution to the copolymer product obtained in step (1) to obtain comparative sample PCE-1.

[0043] Comparative Example 2

[0044] (1) 180.00 g of ethylene glycol monovinyl polyethylene glycol ether with a molecular weight of 3000, 2.00 g of sodium (4-vinylphenyl) methanesulfonate, 0.006 g of ferrous sulfate and 145.00 g of water were added to a reactor, and the stirrer and temperature control device were turned on. After the materials were evenly mixed, an acrylic acid aqueous solution (including 17.00 g of acrylic acid and 20.00 g of water), a hydrogen peroxide aqueous solution (including 1.50 g of hydrogen peroxide and 20.00 g of water), a mercaptopropionic acid aqueous solution (including 0.70 g of mercaptopropionic acid and 20.00 g of water), and a BRUGGOLITE E51 aqueous solution (including 0.25 g of BRUGGOLITE E51 and 20.00 g of water) were added dropwise. The initial reaction temperature was 15° C. The dropping time was 1.0 h. The material temperature was controlled to be ≤30° C. After the dropping was completed, the temperature was kept at 1 h to obtain a copolymer product.

[0045] (2) Add 7 g of 32% aqueous sodium hydroxide solution to the copolymer product obtained in step (1) to obtain sample PCE-2.

[0046] Comparative Example 3

[0047] (1) 180.00 g of ethylene glycol monovinyl polyglycol ether with a molecular weight of 3000, 0.006 g of ferrous sulfate and 145.00 g of water were added to a reactor, and the stirrer and temperature control device were turned on. After the materials were evenly mixed, an acrylic acid aqueous solution (including 17.00 g of acrylic acid and 20.00 g of water), a hydrogen peroxide aqueous solution (including 1.50 g of hydrogen peroxide and 20.00 g of water), a mercaptopropionic acid aqueous solution (including 0.70 g of mercaptopropionic acid and 20.00 g of water), and a BRUGGOLITE E51 aqueous solution (including 0.25 g of BRUGGOLITE E51 and 20.00 g of water) were added dropwise. The initial reaction temperature was 15° C. The dropping time was 1.0 h. During the dropping process, the material temperature was controlled to be ≤30° C. After the dropping was completed, the temperature was kept at 1 h to obtain a copolymer product.

[0048] (2) Add 7 g of 32% aqueous sodium hydroxide solution to the copolymer product obtained in step (1) to obtain sample PCE-3.

[0049] Comparative Example 4

[0050] (1) 180.00 g of 4-hydroxybutyl vinyl polyoxyethylene ether with a molecular weight of 3000, 6.00 g of 4-vinyl benzoic acid, 0.005 g of ferrous sulfate and 145.00 g of water were added to the reactor, and the stirrer and temperature control device were turned on. After the materials were evenly mixed, an acrylic acid aqueous solution (including 18.00 g of acrylic acid and 20.00 g of water), a hydrogen peroxide aqueous solution (including 1.30 g of hydrogen peroxide and 20.00 g of water), a thioglycolic acid aqueous solution (including 0.90 g of thioglycolic acid and 20.00 g of water), and a bleaching powder aqueous solution (including 0.30 bleaching powder and 20.00 g of water) were added dropwise. The initial reaction temperature was 13° C., the dropping time was 0.75 h, and the material temperature was controlled to be ≤25° C. During the dropping process, the temperature was kept at 1 h after the dropping was completed to obtain a copolymer product;

[0051] (2) Add 9 g of 32% aqueous sodium hydroxide solution to the copolymer product obtained in step (1) to obtain sample PCE-4.

[0052] Concrete performance testing

[0053] According to GB / T8076-2008, the performance test of the novel polycarboxylate water-reducing agent prepared in Examples 1 to 5 and the comparative samples prepared in Comparative Examples 1 to 3 was carried out at a solid content of 0.16%. The test results are shown in Table 1:

[0054] Table 1 Concrete test results

[0055]

[0056] As shown in Table 1, the comparison between KZJ-1 and PCE-1 shows that after removing the sodium (4-vinylphenyl) methanesulfonate in KZJ-1, the water reduction rate and the 3d, 7d, and 28d compressive strength ratios of the product are slightly reduced; the comparison between KZJ-1 and PCE-2 shows that after removing the 4-vinyloxybenzenesulfonic acid in KZJ-1, the water reduction rate and the 3d, 7d, and 28d compressive strength ratios of the product are slightly reduced; the comparison between KZJ-1 and PCE-3 shows that after removing the sodium (4-vinylphenyl) methanesulfonate in KZJ-1, the water reduction rate and the 3d, 7d, and 28d compressive strength ratios of the product are slightly reduced. After removing sodium (4-vinylphenyl) methanesulfonate and 4-vinyloxybenzenesulfonic acid, the water reduction rate and 3d, 7d, and 28d compressive strength ratios of the product decreased significantly; the comparison results between KZJ-2 and PCE-4 showed that after removing 4-(vinyloxy)benzenesulfonamide in KZJ-2, the water reduction rate of the product remained basically unchanged, but the 3d, 7d, and 28d compressive strength ratios decreased significantly; the products synthesized according to the technical scheme of this patent all have higher water reduction rates and 3d, 7d, and 28d compressive strength ratios.

[0057] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0058] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A polycarboxylate water reducer, characterized in that: A polycarboxylate water-reducing agent produced by polymerization reaction of compound A, compound B, unsaturated macromonomer, unsaturated carboxylic acid and / or unsaturated carboxylic acid anhydride under the action of an initiator and a molecular weight regulator; The compound A is at least one of (4-vinylphenyl)methanesulfonic acid, sodium (4-vinylphenyl)methanesulfonate, 4-vinylphenylacetic acid, 4-vinylbenzoic acid, 2-methyl-2-(4-vinylphenyl)propionic acid, 4-vinyl-benzoic acid methyl ester, 4-vinyl-benzoic acid ethyl ester, 4-vinylphenylethyl ester, and 4-vinylphenyl diethyl phosphate; The compound B is at least one of 4-vinyloxybenzenesulfonic acid, 4-vinyloxybenzoic acid, 4-vinyloxyphenylacetic acid, sodium 4-vinyloxybenzenesulfonate, potassium 4-vinyloxybenzenesulfonate, methyl 4-vinyloxybenzoate, ethyl 4-vinyloxybenzoate, methyl 4-vinyloxyphenylacetate, ethyl 4-vinyloxyphenylacetate, 4-(allyloxy)benzenesulfonamide, 4-(vinyloxy)benzenesulfonamide, 2-(vinyloxy)benzenesulfonamide, and 4-(allyloxy)benzoic acid; The mass ratio of the unsaturated macromonomer, compound A, compound B, unsaturated carboxylic acid and / or unsaturated carboxylic anhydride is 180:(1-5):(1-10):(5-30).

2. A polycarboxylate water-reducing agent according to claim 1, characterized in that: The molecular weight of the unsaturated macromonomer is 600-6000, and the unsaturated macromonomer is at least one of 3-methyl-3-butene-1-polyethylene glycol, 2-methylallyl polyethylene glycol, ethylene glycol monovinyl polyethylene glycol ether, 4-hydroxybutyl vinyl polyoxyethylene ether, methoxy polyethylene glycol methacrylate, and methoxy polyethylene glycol acrylate.

3. A polycarboxylate water-reducing agent according to claim 1, characterized in that: The unsaturated carboxylic acid and / or unsaturated carboxylic anhydride is at least one of acrylic acid, methacrylic acid and maleic anhydride.

4. A polycarboxylate water-reducing agent according to claim 1, characterized in that: The amount of the initiator used is 0.5-3.0% of the total mass of the reactants; the amount of the molecular weight regulator used is 0.2-3.0% of the total mass of the reactants.

5. A polycarboxylate water reducer according to claim 1, characterized in that: The initiator includes a water-soluble redox initiator system or a water-soluble peroxide initiator system reagent.

6. A polycarboxylate water-reducing agent according to claim 1, characterized in that: The molecular weight regulator includes at least one of thioglycolic acid, mercaptoethanol, mercaptopropionic acid, sulfonated mercaptopropionic acid, and sodium hypophosphite.

7. A method for preparing the polycarboxylate water-reducing agent according to any one of claims 1 to 6, characterized in that: At least the following steps are included: The unsaturated macromonomer, compound A, compound B and water are added to the reactor and stirred. After the materials are evenly mixed, unsaturated carboxylic acid and / or unsaturated carboxylic anhydride, initiator and molecular weight regulator are added dropwise. The dropping time is 0.5-2h, the initial reaction temperature is 10-25°C, and the material temperature is controlled at 10-30°C during the dropping process; after the dropping is completed, the temperature is kept for 0.5-1h to obtain a copolymer product; in the copolymer product, a base is added to adjust the pH value of the product to 5-7 or no base is added to adjust the pH value, so as to obtain the polycarboxylate water reducer.

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