Phosphated small monomers containing unsaturated double bonds, process for their preparation and use

Abstract

The application provides a phosphated small monomer containing unsaturated double bonds and a preparation method and application thereof. The phosphated small monomer is obtained by phosphating unsaturated alcohol as raw material. Because the phosphated small monomer contains unsaturated double bonds and has small molecular weight, the structure of the phosphated small monomer is similar to that of polyacrylic monomer, and therefore the phosphated small monomer has high polymerization activity and is extremely easy to carry out polymerization reaction with polyacrylic monomer, unsaturated acid and the like to prepare a water reducing agent. The water reducing agent prepared based on the phosphated small monomer is not easy to be adsorbed by soil, and has good soil resistance.

Description

Technical Field

[0001] This invention belongs to the field of water-reducing agent technology, specifically relating to a phosphoric small monomer containing unsaturated double bonds, its preparation method and application, and a polycarboxylate-type water-reducing agent and its preparation method. Background Technology

[0002] With the booming development of the construction industry, high-quality natural sand and gravel are being consumed in large quantities, forcing construction projects to use aggregates with high mud content. Polycarboxylate superplasticizers are highly sensitive to mud in sand and gravel and are one of the commonly used superplasticizers in the construction field. However, the adsorption capacity of clay minerals in mud for polycarboxylate superplasticizers is much greater than that for cement, resulting in a sharp reduction in the effective components of superplasticizer adsorbed on the cement surface, significantly reducing the performance of the superplasticizer. Furthermore, different clay components have varying effects on the performance of polycarboxylate superplasticizers. To address this issue, there are currently two main research directions both domestically and internationally: one is to compound polycarboxylate superplasticizers with "sacrificial agents" that preferentially adsorb onto clay; the other is to directly develop mud-resistant polycarboxylate superplasticizers with low sensitivity to clay through molecular structure design. Current technologies suffer from complex processes, high costs, and poor mud-resistant effects. Therefore, developing a safe, environmentally friendly, and cost-effective mud-resistant polycarboxylate superplasticizer is a key focus and challenge in current technological research. Summary of the Invention

[0003] To solve all or part of the above-mentioned technical problems, the present invention provides the following technical solutions:

[0004] One objective of this invention is to provide a phosphating monomer containing unsaturated double bonds, the structural formula of which is shown in Formula I:

[0005]

[0006] Wherein, R1 is selected from at least one of the following groups:

[0007]

[0008] R2 is selected from at least one of the following groups:

[0009]

[0010] The phosphating monomers provided by this invention are suitable for preparing water-reducing agents with good anti-mud properties. They contain unsaturated double bonds, have small molecular weights, and a structure similar to polyether macromonomers, thus exhibiting high polymerization activity and readily polymerizing with polyether macromonomers, acrylic acid, etc., to introduce phosphate groups. The phosphating monomers contain 1-3 double bonds in their structure, forming a certain cross-linking structure with polyether macromonomers and acrylic acid. Therefore, water-reducing agents prepared based on these monomers are less easily adsorbed by soil, resulting in better anti-mud properties. In contrast, some existing phosphorus-containing monomers lack unsaturated double bonds and therefore lack polymerization ability. During the preparation of water-reducing agents, they can only rely on the reaction between phosphate groups and hydroxyl groups, resulting in limited polymerization and poor anti-mud properties.

[0011] In some embodiments, the molecular weight of the phosphate monomer is 138–488. Within this molecular weight range, it indicates that the unsaturated alcohol ether has undergone mono- or di-esterification with phosphoric acid, allowing for sufficient polymerization with vinyl polyethylene glycol ether, acrylic acid, etc., introducing phosphate groups and effectively improving the anti-mud effect. If the molecular weight is too low, it indicates that the unsaturated alcohol ether has not undergone esterification with phosphoric acid, making it difficult for phosphoric acid to polymerize with vinyl polyethylene glycol ether, acrylic acid, etc. If the molecular weight is too high, it indicates that the unsaturated alcohol ether has undergone cross-linking with phosphoric acid, significantly reducing polymerization activity and making it difficult to graft onto the polycarboxylate superplasticizer structure.

[0012] In some embodiments, the pH of a 1 wt% aqueous solution of the phosphating monomer is 3 to 5.

[0013] In some embodiments, the moisture content of the phosphating monomer is 5% to 10%, which effectively controls the occurrence of the reverse hydrolysis reaction of the phosphating monomer.

[0014] The second objective of this invention is to provide a method for preparing the phosphated monomers described in the above technical solution. The preparation method includes: subjecting a mixed reaction system containing 100 parts of unsaturated alcohol ether, 50-150 parts of phosphoric acid, 100-300 parts of polyphosphoric acid and 0.5-2.5 parts of polymerization inhibitor to a polymerization reaction to obtain the phosphated monomers.

[0015] The preparation method provided by this invention has a simple production process, low energy consumption, and good economic efficiency. Furthermore, compared to phosphorus-containing compounds prepared from unsaturated acids and phosphoric acid, this invention uses unsaturated alcohol ethers reacting with phosphoric acid. Unsaturated alcohol ethers and phosphoric acid are more prone to esterification, resulting in unsaturated phosphate esters with activity closer to vinyl polyethylene glycol ethers, leading to a more complete and uniform polymerization reaction and a better water-reducing agent.

[0016] In some embodiments, the preparation method specifically includes: heating 100 parts of unsaturated alcohol ether to 40-60°C within 30 minutes under conditions of -0.02 to -0.10 MPa; adding 0.5-2.5 parts of polymerization inhibitor to the unsaturated alcohol ether at 40-60°C under a protective atmosphere to obtain a mixture; adding 100-300 parts of polyphosphoric acid and 50-150 parts of phosphoric acid to the mixture to carry out the polymerization reaction, while maintaining stirring for 120-360 minutes and maintaining the reaction temperature at 50-70°C; after all polyphosphoric acid and phosphoric acid have been added, isothermal ripening at 50-70°C for 60-90 minutes to obtain a phosphorylated small monomer containing unsaturated double bonds.

[0017] In some embodiments, in the preparation method, 100-300 parts of polyphosphoric acid are added to the mixture in batches, and 50-150 parts of phosphoric acid are added to the mixture at a constant rate to carry out the polymerization reaction.

[0018] In some embodiments, the preparation method specifically includes: heating 100 parts of unsaturated alcohol ether to 45-55°C within 10-20 minutes under conditions of -0.04 to -0.08 MPa.

[0019] In some embodiments, the flow rate of the protective atmosphere is 1 to 5 mL / min, preferably 2 to 4 mL / min.

[0020] In some embodiments, the protective atmosphere includes, but is not limited to, nitrogen.

[0021] In some embodiments, the preparation method includes adding 100-300 parts of polyphosphoric acid in batches to the mixture over 10-30 minutes. Preferably, the addition is done over 15-25 minutes.

[0022] In some embodiments, the 50-150 parts of phosphoric acid are added to the mixture at a uniform rate over 30-90 minutes. Preferably, they are added to the mixture at a uniform rate over 45-75 minutes.

[0023] In some embodiments, the polymerization reaction is carried out at a temperature of 55–65°C. Specifically, 100–300 parts of polyphosphoric acid and 50–150 parts of phosphoric acid are added to the mixture in batches to carry out the polymerization reaction, while stirring is maintained for 120–360 min and the reaction temperature is maintained at 55–65°C. After all the polyphosphoric acid and phosphoric acid have been added, the mixture is aged at a constant temperature of 55–65°C for 60–90 min to obtain a phosphorylated monomer containing unsaturated double bonds.

[0024] In some embodiments, the stirring time is preferably 180 to 300 minutes.

[0025] In some embodiments, the constant temperature curing time is preferably 70-80 minutes.

[0026] In some typical embodiments, the preparation method includes:

[0027] 1) Weigh 100 parts of unsaturated alcohol ether and place them in a reaction vessel. Evacuate the reaction vessel to -0.02 to -0.10 MPa, turn on the stirrer, and raise the temperature to 40 to 60°C within 30 minutes.

[0028] 2) Add 0.5 to 2.5 parts of the polymerization inhibitor to the unsaturated alcohol ether to obtain a mixture, while continuously purging nitrogen gas for protection at a flow rate of 1 to 5 mL / min;

[0029] 3) Add 100-300 parts of polyphosphoric acid to the mixture within 10-30 min, and simultaneously add 50-150 parts of phosphoric acid dropwise at a uniform rate within 30-90 min to carry out the polymerization reaction. During the addition of polyphosphoric acid and phosphoric acid, maintain stirring for 120-360 min and control the temperature to be stable at 50-70℃.

[0030] 4) After the addition is complete, maintain a constant temperature for 60-90 minutes to mature the phosphorylated monomers containing unsaturated double bonds.

[0031] In some embodiments, the unsaturated alcohol ether includes at least one of allyl alcohol, methyl allyl alcohol, isopentenyl alcohol, vinyl glycol ether, vinyl diethylene glycol ether, and 4-hydroxybutyl vinyl ether.

[0032] Furthermore, the unsaturated alcohol ether preferably includes at least one of vinyl glycol ether, vinyl diethylene glycol ether, and 4-hydroxybutyl vinyl ether. Because vinyl glycol ether, vinyl diethylene glycol ether, and 4-hydroxybutyl vinyl ether contain ether bonds in their structures, the synthesized water-reducing agent exhibits better adaptability in mud-containing concrete.

[0033] In some embodiments, the polymerization inhibitor includes at least one of hydroquinone, phenothiazine, p-hydroxyanisole, and p-tert-butylcatechol.

[0034] Furthermore, the polymerization inhibitor preferably includes hydroquinone and / or phenothiazine. Hydroquinone and / or phenothiazine have better polymerization inhibition effects and are less prone to discoloration.

[0035] In some embodiments, the concentration of phosphoric acid is 85 wt%.

[0036] In some embodiments, the polyphosphoric acid has a molecular weight of 337.93, thereby obtaining a phosphorylated small monomer with suitable molecular weight and reactivity.

[0037] In some embodiments, the mixed reaction system contains 100 parts of unsaturated alcohol ether, 75-125 parts of phosphoric acid, 150-250 parts of polyphosphoric acid, and 0.5-2.5 parts of polymerization inhibitor.

[0038] The third objective of this invention is to provide the application of the phosphorized small monomers containing unsaturated double bonds described in any of the above technical solutions in the preparation of water-reducing agents.

[0039] The fourth objective of this invention is to provide a polycarboxylate superplasticizer, wherein, by mass percentage, the raw materials of the polycarboxylate superplasticizer include 130-170 parts of the phosphating monomer containing unsaturated double bonds as described in claim 1 or 2, 280-320 parts of vinyl polyethylene glycol ether, 26-34 parts of acrylic acid, 5-7 parts of sodium hypophosphite, 0.5-0.15 parts of 1 wt% ferrous sulfate solution, 2.5-3.5 parts of 27.5 wt% hydrogen peroxide, 0.6-0.8 parts of vitamin C, and 420-560 parts of water.

[0040] The fifth objective of this invention is to provide a method for preparing the polycarboxylate superplasticizer, wherein a mixed reaction system comprising 280-320 parts of vinyl polyethylene glycol ether, 26-34 parts of acrylic acid, 130-170 parts of the phosphoric monomer containing unsaturated double bonds as described in claim 1 or 2, 5-7 parts of sodium hypophosphite, 0.5-0.15 parts of 1 wt% ferrous sulfate solution, 2.5-3.5 parts of 27.5 wt% hydrogen peroxide, 0.6-0.8 parts of vitamin C, and 420-560 parts of water is subjected to a polymerization reaction to obtain the polycarboxylate superplasticizer.

[0041] In some embodiments, the preparation method specifically includes: uniformly mixing 280-320 parts of vinyl polyethylene glycol ether, 5-7 parts of sodium hypophosphite, 8-12 parts of acrylic acid, 90-110 parts of phosphating monomers containing unsaturated double bonds, 0.5-0.15 parts of 1 wt% ferrous sulfate solution, 2.5-3.5 parts of 27.5 wt% hydrogen peroxide, and 300-400 parts of water to form a first material;

[0042] 18-22 parts of acrylic acid, 40-60 parts of phosphoric monomers containing unsaturated double bonds and 40-60 parts of water are mixed evenly to form the second material;

[0043] Mix 0.6 to 0.8 parts of vitamin C and 80 to 100 parts of water evenly to form the third material;

[0044] The second and third materials are added to the first material in batches to react and obtain the polycarboxylate superplasticizer.

[0045] In some embodiments, the preparation method specifically includes: simultaneously adding the second material and the third material to the first material, wherein the second material is added within 45 minutes and the third material is added within 55 minutes, stirring is maintained during the addition process, and after the second material and the third material are added, the obtained mixed reaction system is kept at a constant temperature of 15-45°C for 30-120 minutes.

[0046] In some embodiments, the preparation method of the first material specifically includes: first, uniformly mixing the water, vinyl polyethylene glycol ether, and sodium hypophosphite in the specified mass fraction until the vinyl polyethylene glycol ether and sodium hypophosphite are completely dissolved; then adding the acrylic acid, phosphating monomer, and ferrous sulfate in the specified mass fraction, stirring until uniformly mixed; and then adding the hydrogen peroxide in the specified mass fraction to obtain the base material.

[0047] Compared with the prior art, the present invention has at least the following beneficial effects:

[0048] The preparation process of the phosphoric monomer containing unsaturated double bonds provided by this invention is simple, energy-efficient, and economical. The pH value of a 1 wt% aqueous solution of the prepared phosphoric monomer is 3-5, the water content is 5%-10%, and the molecular weight is 138-488. The water-reducing agent synthesized based on the phosphoric monomer has good anti-mud effect.

[0049] The polycarboxylate superplasticizer provided by this invention contains carboxyl, hydroxyl, and phosphate groups. The carboxyl and hydroxyl groups have good water-reducing effects, while the phosphate groups and cross-linking structure have good anti-adsorption effects on mud in concrete aggregates. This ensures the water-reducing and slump-maintaining effects of the polycarboxylate superplasticizer in concrete with high mud content, effectively improving the construction quality of concrete. The polycarboxylate superplasticizer with added phosphate monomers has an initial spread of 550-600 mm in concrete with different mud contents, and the spread remains at 500-550 mm after 60 minutes. Detailed Implementation

[0050] The technical solutions of the present invention will be described in detail below with reference to specific embodiments, so that those skilled in the art can better understand and implement the technical solutions of the present invention. The specific functional details disclosed herein should not be construed as limiting, but are merely intended to form the basis of the claims and to teach those skilled in the art to employ the representative basis of the invention in different ways in any suitable detailed embodiment.

[0051] Unless otherwise specified, all raw materials and reagents used in this invention are commercially available. The cement used in the concrete preparation in Table 2 below was purchased from Ningbo Conch Cement Co., Ltd., the fly ash and mineral powder were purchased from Ningbo Yinzhou Tuotou Fly Ash Co., Ltd., the manufactured sand and gravel were purchased from Ningbo Yinzhou Nanyang Manufactured Sand Co., Ltd., and the commercially available anti-mud polycarboxylate superplasticizer was purchased from China Building Materials Zhongyan Technology Co., Ltd.

[0052] Example 1

[0053] This embodiment provides a phosphorylated small monomer containing unsaturated double bonds and its preparation method, as follows:

[0054] Weigh 100 parts of allyl alcohol and place them in a reaction vessel. Evacuate the reaction vessel to -0.02 MPa, turn on the stirrer, and heat to 40°C in 10 minutes.

[0055] Weigh 0.5 parts of the polymerization inhibitor hydroquinone and add it to the above-mentioned allyl alcohol to obtain a mixture. At the same time, nitrogen gas is continuously introduced for protection at a flow rate of 1 mL / min.

[0056] Weigh 100 parts of polyphosphoric acid and add it to the above mixture over 10 minutes. Simultaneously, add 100 parts of phosphoric acid dropwise to the mixture over 60 minutes at a uniform rate, maintaining stirring for 120 minutes. During the reaction, control the temperature to remain stable at 50°C. After the addition is complete, allow the mixture to mature at a constant temperature for 60 minutes to obtain a phosphating monomer containing unsaturated double bonds. The pH of a 1% aqueous solution of the obtained phosphating monomer is 3, and the water content is 10%.

[0057] In this embodiment, polycarboxylate superplasticizer is prepared using the above-mentioned phosphating monomers. The base material, the first drop feed, and the second drop feed are prepared according to the proportions shown in Table 1 below.

[0058] Table 1. Components and proportions of the base material, first drop feed, and second drop feed required for the preparation of the water-reducing agent.

[0059]

[0060] 360 kg of deionized water, 300 kg of vinyl polyethylene glycol ether, and 6 kg of sodium hypophosphite were added sequentially to a reaction vessel. Stirring was started until the vinyl polyethylene glycol ether and sodium hypophosphite were completely dissolved. Then, 10 kg of acrylic acid, 100 kg of phosphating monomer, and 0.1 kg of 1% ferrous sulfate solution were added. After stirring for 5 minutes, 3.0 kg of 27.5% hydrogen peroxide was added to obtain the base material.

[0061] The first and second drops of the pre-prepared additive are added to the above-mentioned base material. The first drop is added at a uniform rate within 45 minutes, and the second drop is added at a uniform rate within 55 minutes. After the second drop is added, the mixture is kept at a constant temperature of 15-45℃ for 60 minutes to obtain the water-reducing agent.

[0062] The prepared polycarboxylate superplasticizer was applied to C30 concrete with a mud content of 5% in manufactured sand. The concrete mix proportions are shown in Table 2.

[0063] Table 2 Concrete Mix Proportions

[0064] Material cement fly ash Mineral powder Manufactured sand pebbles Water reducing agent water Dosage / kg 280 40 40 770 1045 2.0 160

[0065] The above-mentioned concrete was tested in accordance with GB 8076-2008 "Concrete Admixtures". The results showed that when 2.0 kg of the polycarboxylate superplasticizer prepared according to this invention, synthesized based on phosphated small monomers containing unsaturated double bonds, was added to C30 concrete with a mud content of 5%, the initial spread of the concrete was 550 mm, and the spread after 60 minutes was 500 mm.

[0066] Examples 2-6

[0067] The difference between Examples 2-6 and Example 1 lies only in that, in the preparation process of phosphoric monomers containing unsaturated double bonds, Examples 2-6 replace the specific types of unsaturated alcohol ethers used, the content of phosphoric acid and polyphosphoric acid, the type and content of polymerization inhibitors, and the relevant process conditions as shown in Table 3 below.

[0068] Table 3. Relevant raw material components and related process conditions for Examples 1-6

[0069] Raw materials, operating parameters Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 allyl alcohol 100 0 0 0 0 0 Methyl allyl alcohol 0 100 0 0 0 0 Isopentenol 0 0 100 0 0 0 Vinyl glycol ether 0 0 0 100 0 0 Vinyl diethylene glycol ether 0 0 0 0 100 0 4-Hydroxybutylvinyl ether 0 0 0 0 0 100 Phosphoric acid 100 150 125 100 75 50 Polyphosphoric acid 100 150 200 250 300 280 hydroquinone 0.5 0 0 0 2.5 1.0 Phenothiazide 0 1.0 0 0 0 1.5 p-hydroxyanisole 0 0 1.5 0 0 0 p-tert-butylcatechol 0 0 0 2.0 0 0 Vacuum / MPa -0.02 -0.04 -0.06 -0.08 -0.10 -0.05 Heating time / min for unsaturated alcohol ethers 10 15 20 25 30 18 Heating temperature of unsaturated alcohol ethers / °C 40 45 50 55 60 60 Nitrogen flow rate / mL / min 1 2 3 4 5 2.5 Polyphosphoric acid addition time / min 10 15 20 25 30 24 Phosphoric acid dropping time / min 60 90 80 75 30 45 Stirring time / min 120 180 240 300 360 260 Reaction temperature / °C 50 55 60 65 70 70

[0070] The pH value and water content of the 1 wt% aqueous solutions of phosphorylated monomers containing unsaturated double bonds prepared in Examples 1-6 are shown in Table 4.

[0071] Table 4. pH value and water content of 1% aqueous solutions of the phosphorinated monomers prepared in Examples 1-6

[0072]

[0073] The unsaturated double bond-containing phosphated monomers obtained in Examples 2 to 6 were used to prepare polycarboxylate superplasticizers according to the proportions and synthesis process shown in Table 1 of Example 1. The obtained polycarboxylate superplasticizers were applied to C30 concrete with a mud content of 5% according to the proportions shown in Table 2, and the concrete performance was tested. The results are shown in Table 5.

[0074] Comparative Example 1

[0075] The only difference between Comparative Example 1 and Example 1 is that the unsaturated double bond-containing phosphating monomers prepared in this invention are not added during the preparation of the water-reducing agent. The rest is carried out in the same way as Table 1 and process shown in Example 1 to obtain the water-reducing agent. The obtained water-reducing agent is applied to C30 concrete with a mud content of 5% according to the ratio shown in Table 2, and the concrete performance is tested. The results are shown in Table 5.

[0076] Comparative Example 2

[0077] The only difference between Comparative Example 2 and Example 1 is that, in the preparation process of the water-reducing agent, the phosphating monomers containing unsaturated double bonds prepared in this invention were replaced with commercially available anti-mud polycarboxylate water-reducing agent (China Building Materials Zhongyan Technology Co., Ltd.). The rest of the process was carried out in the same manner as shown in Table 1 of Example 1 to obtain the water-reducing agent. The obtained water-reducing agent was applied to C30 concrete with a mud content of 5% according to the proportion shown in Table 2, and the concrete performance was tested. The results are shown in Table 5.

[0078] Comparative Example 3

[0079] The difference from Example 1 is that, in the preparation process of the water-reducing agent, the content of phosphating monomers in the base material and the dripping material is 80 and 40 parts by weight, respectively. The other procedures are the same as in Example 1 to obtain the water-reducing agent. The obtained water-reducing agent is applied to C30 concrete with a mud content of 5% according to the proportion shown in Table 2, and the concrete performance is tested. The results are shown in Table 5.

[0080] Comparative Example 4

[0081] The difference from Example 1 is that, in the preparation process of the water-reducing agent, the content of phosphating monomers in the base material and the dripping material is 120 and 70 parts by weight, respectively. The other procedures are the same as in Example 1 to obtain the water-reducing agent. The obtained water-reducing agent is applied to C30 concrete with a mud content of 5% according to the proportion shown in Table 2, and the concrete performance is tested. The results are shown in Table 5.

[0082] Comparative Example 5

[0083] By weight, 5 parts of phosphorus oxychloride, 1 part of methanol and 0.05 parts of aluminum chloride were added to the second reaction vessel, the temperature was controlled at 30°C and stirred for 0.5 h, then 5 parts of acrylic acid were added dropwise to the second reaction vessel, the temperature was controlled at 50°C and the reaction was carried out for 3 h, and then cooled to room temperature to obtain phosphate ester oligomer.

[0084] A water-reducing agent was prepared by replacing the phosphate oligomer in Example 1 with the phosphate ester oligomer, and applied to C30 concrete with a mud content of 5% according to the proportions shown in Table 2. The concrete performance was then tested, and the results are shown in Table 5.

[0085] Table 5. Performance of concrete in Examples 1-6 and Comparative Examples 1-5

[0086] Group Initial expansion / mm 60min expansion / mm Example 1 550 500 Example 2 600 510 Example 3 570 530 Example 4 580 550 Example 5 580 545 Example 6 570 520 Comparative Example 1 495 300 Comparative Example 2 520 350 Comparative Example 3 450 300 Comparative Example 4 530 490 Comparative Example 5 500 400

[0087] As shown in Table 5, the polycarboxylate superplasticizer synthesized based on the phosphorized small monomers containing unsaturated double bonds of the present invention has an initial spread of 550-600 mm in C30 concrete with a mud content of 5%, and the spread still reaches 500-550 mm after 60 minutes, which is superior to commercially available polycarboxylate superplasticizers.

[0088] All aspects, embodiments, features, and examples of this invention are to be regarded as illustrative in all respects and are not intended to limit the invention, the scope of which is defined only by the claims. Other embodiments, modifications, and uses will become apparent to those skilled in the art without departing from the spirit and scope of the invention as claimed.

[0089] In addition, the inventors of this case also conducted experiments with other raw materials, process operations, and process conditions described in this specification, referring to the aforementioned embodiments, and obtained relatively ideal results in all cases.

[0090] Although the invention has been described with reference to illustrative embodiments, those skilled in the art will understand that various other changes, omissions, and / or additions can be made without departing from the spirit and scope of the invention, and that elements of the embodiments can be substituted with substantially equivalents. Furthermore, many modifications can be made without departing from the scope of the invention to adapt particular situations or materials to the teachings of the invention. Therefore, this invention is not intended to be limited to the specific embodiments disclosed for carrying out the invention, but rather is intended to encompass all embodiments falling within the scope of the appended claims. Moreover, unless specifically stated otherwise, any use of the terms first, second, etc., does not indicate any order or importance, but is used to distinguish one element from another.

Claims

1. A polycarboxylate superplasticizer, characterized in that: By weight, the raw materials of the polycarboxylate superplasticizer include 130-170 parts of phosphating monomers containing unsaturated double bonds, 280-320 parts of vinyl polyethylene glycol ether, 26-34 parts of acrylic acid, 5-7 parts of sodium hypophosphite, 0.5-0.15 parts of 1 wt% ferrous sulfate solution, 2.5-3.5 parts of 27.5 wt% hydrogen peroxide, 0.6-0.8 parts of vitamin C, and 420-560 parts of water; The structural formula of the phosphorylated monomer containing unsaturated double bonds is shown in Formula I: ； Wherein, R1 is selected from at least one of the following groups: ； R2 is selected from at least one of the following groups: ； The phosphating monomer has a molecular weight of 138-488, and its preparation method includes: by mass, carrying out a polymerization reaction of a first mixed reaction system containing 100 parts of unsaturated alcohol ether, 50-150 parts of phosphoric acid, 100-300 parts of polyphosphoric acid and 0.5-2.5 parts of polymerization inhibitor to obtain the phosphating monomer.

2. The polycarboxylate superplasticizer according to claim 1, characterized in that: The pH value of the 1wt% aqueous solution of the phosphate monomer is 3 to 5; and / or the water content of the phosphate monomer is 5% to 10%.

3. The polycarboxylate superplasticizer according to claim 1, characterized in that, The preparation method of the phosphating monomer specifically includes: Under conditions of -0.02 to -0.10 MPa, 100 parts of unsaturated alcohol ether were heated to 40 to 60 °C within 30 min; Under a protective atmosphere, 0.5 to 2.5 parts of the polymerization inhibitor were added to the unsaturated alcohol ether at a temperature of 40 to 60°C to obtain a mixture; Add 100-300 parts of polyphosphoric acid and 50-150 parts of phosphoric acid to the mixture to carry out the polymerization reaction, while maintaining stirring for 120-360 min and maintaining the reaction temperature at 50-70°C. After all polyphosphoric acid and phosphoric acid have been added, the mixture is aged at a constant temperature of 50-70℃ for 60-90 minutes to obtain phosphorylated small monomers containing unsaturated double bonds.

4. The polycarboxylate superplasticizer according to claim 3, characterized in that: Under conditions of -0.04 to -0.08 MPa, the 100 parts of unsaturated alcohol ether were heated to 45 to 55 °C within 10 to 20 minutes.

5. The polycarboxylate superplasticizer according to claim 3, characterized in that: The flow rate of the protective atmosphere is 1~5 mL / min.

6. The polycarboxylate superplasticizer according to claim 3, characterized in that: The 100-300 parts of polyphosphoric acid are added to the mixture in batches over 10-30 minutes.

7. The polycarboxylate superplasticizer according to claim 3, characterized in that: The 50-150 parts of phosphoric acid are added to the mixture at a uniform rate over 30-90 minutes.

8. The polycarboxylate superplasticizer according to claim 3, characterized in that: The polymerization reaction is carried out at a temperature of 55-65°C.

9. The polycarboxylate superplasticizer according to claim 3, characterized in that: The stirring time is 180~300 minutes.

10. The polycarboxylate superplasticizer according to claim 3, characterized in that: The constant temperature curing time is 70-80 minutes.

11. The polycarboxylate superplasticizer according to claim 1, characterized in that: The unsaturated alcohol ethers include at least one of allyl alcohol, methyl allyl alcohol, isopentenyl alcohol, vinyl glycol ether, vinyl diethylene glycol ether, and 4-hydroxybutyl vinyl ether.

12. The polycarboxylate superplasticizer according to claim 11, characterized in that: The unsaturated alcohol ether includes at least one of vinyl glycol ether, vinyl diethylene glycol ether, and 4-hydroxybutyl vinyl ether.

13. The polycarboxylate superplasticizer according to claim 1, characterized in that: The polymerization inhibitor includes at least one of hydroquinone, phenothiazine, p-hydroxyanisole, and p-tert-butylcatechol.

14. The polycarboxylate superplasticizer according to claim 13, characterized in that: The polymerization inhibitors include hydroquinone and / or phenothiazine.

15. The polycarboxylate superplasticizer according to claim 1, characterized in that: In the first mixed reaction system, there are 100 parts of unsaturated alcohol ether, 75-125 parts of phosphoric acid, 150-250 parts of polyphosphoric acid, and 0.5-2.5 parts of polymerization inhibitor.

16. The method for preparing the polycarboxylate superplasticizer according to any one of claims 1-15, characterized in that: A second mixed reaction system comprising 280-320 parts of vinyl polyethylene glycol ether, 26-34 parts of acrylic acid, 130-170 parts of the phosphorinated monomer containing unsaturated double bonds, 5-7 parts of sodium hypophosphite, 0.5-0.15 parts of 1 wt% ferrous sulfate solution, 2.5-3.5 parts of 27.5 wt% hydrogen peroxide, 0.6-0.8 parts of vitamin C, and 420-560 parts of water is subjected to a polymerization reaction to obtain the polycarboxylate superplasticizer.

17. The method for preparing the polycarboxylate superplasticizer according to claim 16, characterized in that, Specifically, it includes: 280-320 parts of vinyl polyethylene glycol ether, 5-7 parts of sodium hypophosphite, 8-12 parts of acrylic acid, 90-110 parts of phosphating monomers containing unsaturated double bonds, 0.5-0.15 parts of 1 wt% ferrous sulfate solution, 2.5-3.5 parts of 27.5 wt% hydrogen peroxide, and 300-400 parts of water are mixed evenly to form the first material; 18-22 parts of acrylic acid, 40-60 parts of phosphoric monomers containing unsaturated double bonds and 40-60 parts of water are mixed evenly to form the second material; Mix 0.6-0.8 parts of vitamin C and 80-100 parts of water evenly to form the third material; The second and third materials are added to the first material in batches to react and obtain the polycarboxylate superplasticizer.

18. The method for preparing the polycarboxylate superplasticizer according to claim 17, characterized in that: Simultaneously, the second and third materials are added to the first material, with the second material added within 45 minutes and the third material added within 55 minutes. Stirring is maintained during the addition process. After the second and third materials are added, the resulting mixed reaction system is aged at a constant temperature of 15-45°C for 30-120 minutes.

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