Phosphate ester and preparation method thereof as well as phosphate water reducer and preparation method thereof

Abstract

The invention provides phosphate and a preparation method thereof as well as a phosphate water reducer and a preparation method thereof, a p-methoxyphenol compound and p-hydroxybenzyl alcohol are subjected to condensation polymerization under the action of an acid catalyst, then under the action of a p-toluenesulfonic acid catalyst, a prepolymer is formed through bulk polymerization, and then the prepolymer and a phosphorylation reagent are subjected to esterification reaction, so that the phosphate water reducer is obtained. Obtaining phosphate ester; according to the preparation method, the unsaturated epoxy polyol is used as a raw material, the phosphate ester is used for reacting with the unsaturated epoxy polyol to obtain the phosphoric acid water reducer, the reaction degree is high, and meanwhile, the damage of high-temperature and strong-acid environments to molecular structures and the generation of phosphate diester byproducts in the traditional phosphorylation reaction are avoided. The phosphate group-containing water reducer produced by the invention has the advantages of good slump retaining performance, good adaptability in different types of cement, insensitivity to the content of mud and powder in a concrete material, low sensitivity to clay, capability of improving the workability of concrete, and the like.

Description

Technical Field

[0001] The invention belongs to the field of material preparation, and specifically relates to a phosphate ester and a preparation method thereof, a phosphate-based water reducer and a preparation method thereof. Background Art

[0002] Polycarboxylate water reducer is an important admixture in concrete. It is widely used in the concrete industry due to its advantages such as high water reduction rate, low dosage, and green environmental protection. However, a large number of engineering examples and studies have shown that in the application of high-strength concrete, there are problems such as high viscosity, slow flow rate, and fast hydration. Although other additives such as foaming agents, slump retaining agents, and retarders can be added to the polycarboxylate water reducer to improve its performance, it will also bring problems such as high cost, prolonged setting time, and low strength.

[0003] The study found that the adsorption capacity of the phosphate group is stronger than that of the sulfonic acid group and the carboxylic acid group, and it has a stronger complexing ability for calcium ions in aqueous solution and on the surface of cement particles. Through competitive adsorption, it is preferentially adsorbed on the surface of cement particles and clay particles, with a faster adsorption rate and stronger electrostatic repulsion, avoiding the adverse effects of sulfates and sulfonates on the performance of water reducers. In addition, the adjacent negative charges of the phosphate groups adsorbed on the surface of cement particles produce electrostatic repulsion, which can make the main chain more rigid, which is conducive to the initial adsorption of molecules and improves the initial dispersion ability.

[0004] Although phosphate-based water reducers have good effects on the anti-clay performance, dispersibility, and slump resistance of cement concrete, the current research on phosphate-based water reducers is still insufficient and there are some problems and shortcomings.

[0005] At present, the most common method for synthesizing phosphoric acid water reducer is: the first method is to add an olefin monomer containing a phosphoric acid group as the third monomer to the synthesis system of polycarboxylic acid. Related reports include: the patent with publication number CN105236806 A published on January 13, 2016 has a highly adaptable phosphoric acid-modified polycarboxylic acid water reducer and its preparation method, and the unsaturated phosphoric acid monomer is prepared by the esterification reaction between 2-phospho-1,2,4-tricarboxylic acid butane and allyl alcohol, and then it is copolymerized with isopentanol polyoxyethylene ether and acrylic acid. The obtained product has good sulfate ion resistance and mud resistance, which can meet the needs of some special projects. The patent with publication number CN103848944A published on June 11, 2014 discloses a method for preparing a super slow-setting polycarboxylic acid water-reducing agent, which uses unsaturated polyether macromonomers, unsaturated carboxylic acid / anhydride small monomers, unsaturated sulfonic acid small monomers and vinyl phosphate small monomers as raw materials, and directly obtains the product by free radical copolymerization in a neutral aqueous solution system. The obtained finished product can be used in concrete with a long setting time requirement, thereby eliminating the process of compounding a retarder, improving production efficiency, and making the product more uniform and stable, thereby avoiding abnormal setting time of concrete; the patent with publication number CN103833940 published on June 4, 2014 discloses a method for preparing a super slow-setting polycarboxylic acid water-reducing agent, which uses unsaturated polyether macromonomers, unsaturated carboxylic acid / anhydride small monomers, unsaturated sulfonic acid small monomers and vinyl phosphate small monomers as raw materials, and directly obtains the product by free radical copolymerization in a neutral aqueous solution system. The obtained finished product can be used in concrete with a long setting time requirement, thereby eliminating the process of compounding a retarder, improving production efficiency, and making the product more uniform and stable, thereby avoiding abnormal setting time of concrete; A's patent discloses a phosphine-containing polycarboxylic acid water-reducing agent and a preparation method thereof. N, N-di(phosphonic acid methyl)aminobutyl maleic acid monoester is added to the polymerization system of isoprene polyoxyethylene ether and acrylic acid / methacrylic acid. The synthesized sample has excellent collapse-preserving ability, providing a reliable and stable solution to the long-term collapse-preserving problem, and the process is safe, environmentally friendly and low-cost. Although the first method above is simple and direct, it also has obvious defects. For example, the small molecule phosphoric acid monomer is expensive and has low purity. The monomer contains a large amount of phosphoric acid diene components, which can make the polymerization easily out of control and cross-linking. In addition, the phosphoric acid group has a stabilizing effect on free radicals, which can reduce the polymerization rate and even cause the reaction to fail.

[0006] The second method is to firstly synthesize a prepolymer by free radical polymerization, and then perform phosphorylation modification on the polymer to finally obtain a phosphoric acid water reducer. Related reports include: a method for preparing a mud-resistant and slump-retaining polycarboxylic acid water reducer containing a phosphate ester group in a patent with publication number CN 106008853A published on October 12, 2016, wherein a halogen-containing unsaturated monomer, an unsaturated acid small monomer, an unsaturated polyether macromonomer or an unsaturated ester macromonomer is copolymerized to obtain a polycarboxylic acid water reducer prepolymer, which is then subjected to Arbuzov reaction with an alkyl phosphate to obtain a copolymer product containing a phosphate ester group. After the reaction is completed, the pH value is adjusted, and water is added to obtain a polycarboxylic acid water reducer containing a phosphate group. The product has the advantages of low dosage, high water reduction rate, long slump retention time and strong mud resistance, can avoid the adverse effects of mud-containing aggregates in concrete, and has a simple synthesis process, is easy to control, and has a low production cost; a patent with publication number CN 105418857 published on March 23, 2016 Patent A discloses a preparation method and application of a polycarboxylate water-reducing agent containing a phosphate group, wherein an unsaturated polyether macromonomer, an unsaturated carboxylate ester, and an unsaturated alcohol are copolymerized in an organic solvent to obtain a polycarboxylate water-reducing agent prepolymer, and then the hydroxyl groups on the prepolymer are subjected to an esterification reaction with a phosphoric acid esterifying agent to obtain a polycarboxylate water-reducing agent containing a phosphate group, and the product has excellent water-reducing, slump-retaining, and clay-resistant capabilities; Patent CN105601839 A, published on May 25, 2016, discloses a preparation method and application of a polycarboxylate water-reducing agent containing a phosphate group, wherein an unsaturated polyether macromonomer and an unsaturated acid anhydride are copolymerized to obtain a polycarboxylate water-reducing agent prepolymer, and then the anhydride groups on the prepolymer are subjected to an amidation reaction with a phosphorylating agent to obtain a polycarboxylate water-reducing agent containing a phosphate group. Although the second method avoids the shortcomings of direct free radical polymerization of phosphoric acid monomers, due to the molecular steric hindrance of the prepolymer and the efficiency of phosphorylation modification, the content of effective phosphoric acid groups in the product is too low, and the product performance is greatly affected. At present, this type of product is still in the laboratory research stage. Summary of the invention

[0007] The object of the present invention is to provide a phosphate ester and a preparation method thereof. The phosphate ester is obtained by subjecting a p-methoxyphenol compound and p-hydroxybenzyl alcohol to a polycondensation reaction under the action of an acid catalyst, and then bulk polymerizing the prepolymer under the action of a p-toluenesulfonic acid catalyst, and then reacting the prepolymer with a phosphorylation agent for an esterification reaction. The preparation method is simple and efficient.

[0008] Another object of the present invention is to provide a phosphoric acid-based water reducer and a preparation method thereof, wherein the phosphoric acid-based water reducer is obtained by a ring-opening reaction between the above-mentioned phosphoric acid ester and an unsaturated epoxy polyol, and has excellent performance, strong collapse-preserving ability, good adaptability to cement, insensitivity to the mud and powder content in concrete materials, and improved workability of concrete.

[0009] The specific technical solutions of the present invention are as follows:

[0010] A phosphate ester having the structural formula: R is an alkyl group, and the number of carbon atoms in R is a positive integer of 1-5. Preferably, R is a methyl group or an ethyl group; the value range of a is 2-8.

[0011] The present invention provides a method for preparing a phosphate ester, which specifically comprises:

[0012] The p-methoxyphenol compound, p-hydroxybenzyl alcohol and an acid catalyst are mixed, the catalyst is added dropwise, and the mixture is heated for reaction; then a phosphorylation reagent is added, and the mixture is heated for reaction to obtain the product.

[0013] The molar ratio of the p-methoxyphenol compound to p-hydroxybenzyl alcohol is 1:(1.25-3.5);

[0014] The molar ratio of the p-methoxyphenol compound to the acid catalyst is 1:0.2-0.6;

[0015] The molar ratio of the p-methoxyphenol compound to the catalyst is 1:0.2-0.6.

[0016] The molar ratio of the p-methoxyphenol compound to the phosphorylation reagent is 1:0.3-1.5.

[0017] The structural formula of the p-methoxyphenol compound is R is an alkyl group, and the number of carbon atoms in R is a positive integer of 1-5; preferably, the p-methoxyphenol compound is selected from p-methoxyphenol or 4-ethoxyphenol;

[0018] The acid catalyst is selected from one of glyoxylic acid, propionaldehyde, acetic anhydride or acetic acid;

[0019] The catalyst is p-toluenesulfonic acid;

[0020] The phosphorylation agent is selected from phosphoric acid, phosphorous acid, and polyphosphoric acid; the polyphosphoric acid is preferably H6P4O 13 .

[0021] The structural formula of the p-hydroxybenzyl alcohol is

[0022] The heating reaction is carried out at 90-120° C., the reaction time is 4-10 hours, and the reaction pressure is normal pressure.

[0023] The heat preservation reaction refers to the reaction at 90-120° C., the reaction time is 4-10 hours, and the reaction pressure is normal pressure.

[0024] The reaction equation for preparing phosphate ester is:

[0025]

[0026] The present invention provides a phosphate-based water reducer having the structural formula: Prepared by using the above phosphate ester. R is an alkyl group, R contains a positive integer of 1-5 carbon atoms, R2 represents a normal alkyl group or H, R2 contains a positive integer of 2-10 carbon atoms; R3 contains a positive integer of 2-10 carbon atoms or an unsaturated hydrocarbon group containing a double bond, a is 2-8, b is 4-32, and c is 22-33.

[0027] The present invention provides a method for preparing a phosphoric acid-based water reducer, which is specifically:

[0028] The phosphate ester prepared above is used as a raw material in material A to react with unsaturated epoxy polyol / ether to obtain a phosphoric acid water reducer;

[0029] The molar ratio of the phosphate ester to the unsaturated epoxy polyol / ether is 1-4:20;

[0030] Mix and dissolve unsaturated epoxy polyol / ether and water as a base material, and simultaneously prepare and drop material A and material B. Material A is: acrylic acid, hydroxyethyl acrylate, phosphate and water, and mix them evenly; material B is: mercaptopropionic acid, L-ascorbic acid and water, and mix them evenly. The initial temperature in the reaction container is controlled to be 15° C., and hydrogen peroxide solution is added into the base material at one time. After stirring for 5 minutes, material A and material B are added dropwise. Material A is added dropwise for 50 minutes, and material B is added dropwise for 60 minutes. After the addition of material B is completed, the temperature is kept for 60 minutes, water is added to adjust the polymer concentration, and then liquid alkali with a mass concentration of 30% is added to adjust the pH to 5-6 to obtain the product.

[0031] The structural formula of the unsaturated epoxy polyol / ether is R2 represents a normal alkyl group or H, R2 contains a positive integer of 2-10 carbon atoms; R3 contains a positive integer of 2-10 carbon atoms or an unsaturated hydrocarbon group containing a double bond, and c is 22-33. When R3 is an unsaturated hydrocarbon group containing a double bond, it is preferably: vinyl, allyl, isopropenyl and butenyl, etc. Such compounds can represent unsaturated glycidyl ethers, including but not limited to vinyl glycidyl ether, isopropenyl glycidyl ether, oleyl glycidyl ether, allyl glycidyl ether, p-vinylbenzyl glycidyl ether, o-allylphenyl glycidyl ether, butenyl glycidyl ether, 4-vinylcyclohexyl glycidyl ether, rosin glycidyl ether, cyclohexenyl methyl glycidyl ether, methylallyl glycidyl ether.

[0032] The molecular weight of the phosphoric acid-based water reducer is 10,000-30,000.

[0033] The phosphoric acid water reducing agent prepared by polycondensation reaction of phosphoric acid ester phenyl ether monomer and unsaturated epoxy polyol / ether (MPEG-1) has good water reduction and collapse protection performance and can effectively improve the strength of concrete.

[0034] Under the conditions of the phosphate ester containing benzene rings in the present invention, the phosphate group is introduced into the side chain of the polycarboxylate water-reducing agent polymer, which can effectively enhance the adhesion ability of the polycarboxylate water-reducing agent molecules to the surface of low-surface-energy machine-made sand, thereby reducing the purpose of bleeding and slurry, thereby improving the workability and homogeneity of the concrete mixture; at the same time, the polycarboxylate water-reducing agent molecules can continuously release a large amount of phosphate ions and small-molecule alcohols when hydrolyzed in the cement paste, which can greatly delay the process of cement hydration, thereby playing a role in preventing collapse. The phenol group and the phosphate ester group work synergistically to jointly improve the workability and homogeneity of the concrete mixture, thereby improving the durability and compressive strength of the concrete.

[0035] Compared with the prior art, the invention uses p-methoxyphenol compounds and p-hydroxybenzyl alcohol to undergo polycondensation under the action of an acid catalyst, and then undergoes bulk polymerization under the action of a p-toluenesulfonic acid catalyst to form a prepolymer, and then undergoes an esterification reaction with a phosphorylation agent to obtain a phosphate ester; and then the phosphate ester is reacted with an unsaturated epoxy polyol to obtain a phosphoric acid water reducer, with a high degree of reaction, while avoiding the destruction of the molecular structure by the high temperature and strong acid environment of the traditional phosphorylation reaction and the generation of a phosphate diester by-product. The water-reducing agent containing phosphate and sulfonic acid groups synthesized by the present invention has good slump-retaining performance, good adaptability in different cements, is insensitive to mud and powder content in concrete materials, has low sensitivity to clay, and has the advantages of improving concrete workability, etc., mainly because the phosphate group carries two negative charges, and the introduction of the sulfonic acid group increases the charge density of the side chain, produces an adsorption effect with the positive charge on the surface of the cement particles, can be quickly adsorbed on the surface of the cement particles, and the negative charge covers it. When the cement particles are close to each other, an electrostatic effect can be generated to make it diffuse quickly, thereby achieving a dispersion effect, solving the problems of fast fluidity loss, poor slump-retaining performance and poor adaptability of traditional polycarboxylate water-reducing agents in aggregates containing mud. In addition, the method of the present invention has high reaction efficiency and high utilization rate of phosphate groups. It has broad application prospects. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in combination with the embodiments of the present invention. Obviously, the described embodiments are 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.

[0037] Unless otherwise specified, the test materials and reagents used in the following examples can be obtained from commercial sources.

[0038] If no specific techniques or conditions are specified in the examples, they can be carried out according to the techniques or conditions described in the literature in the art or according to the product instructions.

[0039] The weight average molecular weight, molecular weight distribution (PDI) and water reducing agent peak area ratio of the present invention are determined by Wyatttechnology corporation gel permeation chromatography. (Mobile phase: 0.1 mol / L NaNO3 aqueous solution; Mobile phase speed: 1 ml / min; Injection volume: 20 μl; Sample preparation concentration: 0.5% (sample g / mobile phase g); Detector: Shodex RI-71 differential refractive index detector; Standard: Polyethylene glycol GPC standard (Sigma-Aldrich, molecular weight 1010000, 478000, 263000, 118000, 44700, 18600, 6690, 1960, 628, 232).

[0040] Example 1

[0041] A method for preparing a phosphate ester (PSJ-1), specifically:

[0042] Weigh 124g of p-methoxyphenol and 172.5g of p-hydroxybenzyl alcohol in a clean reactor, then add 14.8g of glyoxylic acid, stir until fully dissolved, then add 34.44g of p-toluenesulfonic acid dropwise to the above solution, and keep the temperature at 100℃ for 4h. Then add 174g of polyphosphoric acid H6P4O 13 (Relative molecular weight: 337.92) was reacted at 100°C for 6 hours to obtain a light pink solid, which is a prepolymer containing a phosphate group (the phosphate ester is denoted as PSJ-1).

[0043] Example 2

[0044] A method for preparing a phosphoric acid-based water reducer, using the phosphate ester PSJ-1 prepared in Example 1 to prepare a phosphoric acid-based water reducer (HPAE-1), specifically:

[0045] 600 g of ethylene oxide with a molecular weight of 3000 and a polyethylene glycol monomethyl ether structure

[0046] and 342g water are added to the reactor and stirred to dissolve as the base material. At the same time, material A and material B are prepared and added dropwise. Material A: 17g acrylic acid, 40g hydroxyethyl acrylate, 8g phosphoric acid prepolymer (PSJ-1, relative molecular mass 400-800) and 20g water, mixed evenly; material B: 1.8g mercaptopropionic acid, 0.5g L-ascorbic acid and 60g water, mixed evenly. The initial temperature in the reaction container is controlled to be 15°C, 3.0g 27.5% hydrogen peroxide solution is added into the reaction solvent at one time, and material A and material B are added dropwise after stirring for 5 minutes. Material A is added dropwise for 50 minutes, and material B is added dropwise for 60 minutes. After the addition of material B is completed, the temperature is kept for 60 minutes, water is added to adjust the polymer concentration, and then 30% liquid alkali is added to adjust the pH to 5-6 to obtain a phosphoric acid-based water reducer, recorded as PAE-1, with a solid content of 40%.

[0047] Comparative Example 1 Conventional collapse-retaining polycarboxylate water reducer

[0048] 600 g of ethylene oxide with a molecular weight of 2400 and a methyl allyl alcohol polyoxyethylene ether structure

[0049] and 342g water were added to the reactor and stirred to dissolve as the base material. At the same time, material A and material B were prepared and added dropwise. Material A: 17g acrylic acid, 42.7g hydroxyethyl acrylate and 20g water, mixed evenly; material B: 1.8g mercaptopropionic acid, 0.5g L-ascorbic acid and 60g water, mixed evenly. The initial temperature in the reaction container was controlled to be 15°C, 3.0g 27.5% hydrogen peroxide solution was added into the base material at one time, and material A and material B were added dropwise after stirring for 5 minutes. Material A was added dropwise for 50 minutes, and material B was added dropwise for 60 minutes. After the addition of material B was completed, the temperature was kept for 60 minutes, water was added to adjust the polymer concentration, and then alkali was added to adjust the pH to 5-6 to obtain a water reducer, recorded as D-1, with a solid content of 40%.

[0050] Comparative Example 2 Conventional phosphate collapse-preserving polycarboxylate water reducer

[0051] 600 g of ethylene oxide with a molecular weight of 3000 and a polyethylene glycol methyl ether structure

[0052] and 342g water were added to the reactor and stirred to dissolve as the base material. A material and B material were prepared and added dropwise at the same time. A material: 17g acrylic acid, 40g hydroxyethyl acrylate, 5.3g methacrylate-2_hydroxyethyl phosphate and 20g water, mixed evenly; B material: 1.8g mercaptopropionic acid, 0.5g L-ascorbic acid and 60g water, mixed evenly. The initial temperature in the reaction container was controlled to be 15°C, 3.0g 27.5% hydrogen peroxide solution was added into the base material at one time, and A material and B material were added dropwise after stirring for 5 minutes. A material was added dropwise for 50 minutes, and B material was added dropwise for 60 minutes. After the addition of B material was completed, the temperature was kept for 60 minutes, water was added to adjust the polymer concentration, and then alkali was added to adjust the pH to 5-6 to obtain a water reducer, which was recorded as D2, and its solid content was 40%.

[0053] The synthesized PAE-1, D-1 and D-2 were subjected to the pure paste test for comparison. The test was conducted in accordance with GB / T8077-2012 "Test method for homogeneity of concrete admixtures". The cement was Conch Cement, the cement dosage was 500g, the water dosage was 145g, and the cement paste fluidity was measured on a flat glass after stirring for 4 minutes. The specific experimental data are shown in Table 1.

[0054] Table 1 Test results of pure slurry with different water reducing agents

[0055]

[0056] It can be seen from the data in Table 1 that, under the same slurry ratio and the same dosage, Example 2 has a longer sustained release effect than Comparative Example 1 and Comparative Example 2, and the later loss is smaller, which indicates that the polyphosphoric acid water reducer of the present invention has better slump retention performance.

[0057] According to GB 8076-2008 "Concrete Admixtures". Cement is Conch Cement, secondary fly ash, machine-made sand (fineness modulus 3.0, mud content 5%), ordinary crushed stone gradation (5-31.5, mud content 1%), and the admixture is 2.4% of the quality of the glue (the ratio of the water-reducing mother liquid to the collapse-preserving mother liquid is 7:3 with a solid content of 10%). The collapse-preserving mother liquid is ME350 from Ningbo Conch New Materials Technology Co., Ltd. The concrete mix ratio is: 165kg water, 280kg cement, 70kg fly ash, 900kg machine-made sand, and 1000kg crushed stone. 6.72g of water reducer is added to 280g of cement, of which 4.7g of the polyphosphoric acid water reducer synthesized by the present invention and 2.02g of ME350 are added to the concrete to test the concrete performance. Specific experimental data are shown in Table 2.

[0058] Table 2 Experimental results of different water reducing agents

[0059]

[0060]

[0061] It can be seen from the data in Table 2 that when Example 1 of the present invention is used in machine-made sand concrete, the concrete mixture state is better, the slump-preserving ability is better, and the 28d compressive strength is better than that of Comparative Examples 1-2. This is because under the condition of introducing the benzene ring-containing phosphate ester in the present invention, the phosphate group is introduced into the polymer side chain of the polycarboxylate water-reducing agent, which can effectively enhance the adhesion ability of the polycarboxylate water-reducing agent molecules to the low surface energy machine-made sand surface, achieve the purpose of reducing water seepage and slurry, thereby improving the workability and homogeneity of the concrete mixture; at the same time, the polycarboxylate water-reducing agent molecules can continuously release a large amount of phosphate ions and small molecule alcohols when hydrolyzed in the cement paste, which can greatly delay the process of cement hydration, thereby playing a role in slump preservation. The phenol group and the phosphate ester group work synergistically to jointly improve the workability and homogeneity of the concrete mixture, thereby improving the durability and compressive strength of the concrete.

[0062] The description of the above embodiments is to facilitate the understanding and use of the invention by those skilled in the art. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative work. Therefore, the present invention is not limited to the above embodiments, and improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the present invention should be within the protection scope of the present invention.

Claims

1. A phosphate ester, wherein the phosphoric acid has the structural formula: is an alkyl group, R contains a positive integer of 1-5 carbon atoms, and the value range of a is 2-8.

2. A method for preparing the phosphate ester according to claim 1, characterized in that The preparation method comprises the following steps: mixing p-methoxyphenol compound, p-hydroxybenzyl alcohol and an acid catalyst, dropping the catalyst, heating for reaction, then adding a phosphorylation reagent, and keeping the temperature for reaction to obtain the product.

3. The preparation method according to claim 2, characterized in that: The molar ratio of the p-methoxyphenol compound to p-hydroxybenzyl alcohol is 1:(1.25-3.5); the molar ratio of the p-methoxyphenol compound to the acid catalyst is 1:0.2-0.6; the molar ratio of the p-methoxyphenol compound to the catalyst is 1:0.2-0.6; the molar ratio of the p-methoxyphenol compound to the phosphorylation agent is 1:0.3-1.

5.

4. The preparation method according to claim 2 or 3, characterized in that: The catalyst is p-toluenesulfonic acid; the phosphorylation agent is selected from phosphoric acid, phosphorous acid, and polyphosphoric acid.

5. The preparation method according to claim 2, characterized in that: The heating reaction is carried out at 90-120° C. and the reaction time is 4-10 hours.

6. The preparation method according to claim 2 or 5, characterized in that: The heat preservation reaction is carried out at 90-120° C. and the reaction time is 4-10 hours.

7. A phosphate-based water reducer, characterized in that: The method is prepared by using the phosphate ester described in claim 1.

8. A method for preparing the phosphoric acid-based water reducer according to claim 7, characterized in that: The preparation method of the phosphoric acid-based water reducer is specifically as follows: phosphoric acid ester as a raw material in material A reacts with unsaturated epoxy polyol / ether to obtain the phosphoric acid water reducer.

9. The preparation method according to claim 7, characterized in that: The molar ratio of the phosphate ester to the unsaturated epoxy polyol / ether is 1-4:

20.

10. The preparation method according to claim 8 or 9, characterized in that: The reverse preparation method is specifically as follows: unsaturated epoxy polyol / ether is mixed and dissolved with water as a base material, and material A and material B are prepared and added dropwise at the same time, wherein material A comprises acrylic acid, hydroxyethyl acrylate, phosphate and water, and the mixture is uniformly mixed; material B comprises mercaptopropionic acid, L-ascorbic acid and water, and the mixture is uniformly mixed, the initial temperature in the reaction container is controlled to be 15° C., a hydrogen peroxide solution is added into the base material at one time, and after stirring for 5 minutes, material A and material B are added dropwise, material A is added dropwise for 50 minutes, and material B is added dropwise for 60 minutes. After the addition of material B is completed, the mixture is kept warm for 60 minutes, water is added to adjust the polymer concentration, and then liquid alkali with a mass concentration of 30% is added to adjust the pH to 5-6, thereby obtaining the product.

Images