High-adaptability water-retaining polycarboxylic acid water reducer mother liquor and preparation method thereof
By preparing a highly adaptable water-retaining polycarboxylate superplasticizer mother liquor, modifying starch and isomeric esters to improve the steric hindrance effect between cement particles, and introducing specific components to enhance water retention, the problems of adaptability and fluidity loss of polycarboxylate superplasticizer were solved, thereby improving the workability and early strength of concrete and reducing costs.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-27
- Publication Date
- 2026-04-10
AI Technical Summary
Existing polycarboxylate superplasticizers are sensitive to the mud and stone powder content of sand and gravel, have poor adaptability, lose fluidity quickly over time, are difficult to transport and pump over long distances, and have the problem of bleeding and segregation.
The mother liquor of the highly adaptable water-retaining polycarboxylate superplasticizer is composed of base solution, A solution, B solution and C solution. Modified starch and isomeric esters are introduced to increase the steric hindrance effect between cement particles and improve adaptability. Hydroxypropyl sodium hypochlorite oxidized starch and hydroxypropyl peroxide oxidized starch are added to improve water retention. Low viscosity hydroxypropyl methylcellulose is combined to improve adhesion.
It significantly improves the adaptability and water retention of concrete, reduces fluidity loss over time, enhances the workability and early strength of concrete, solves the problem of bleeding and segregation, reduces costs, and reduces the use of petrochemical products.
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Abstract
Description
Technical Field
[0001] This invention relates to the field of building admixtures, and more particularly to a highly adaptable water-retaining polycarboxylate superplasticizer mother liquor and its preparation method. Background Technology
[0002] Concrete admixtures have become one of the five essential components in concrete preparation. The development of water-reducing agents has mainly gone through three stages: the first generation was lignosulfonate water-reducing agents; the second generation included naphthalene-based, melamine-based, and aminosulfonic acid-based water-reducing agents; and the third generation is polycarboxylate high-performance water-reducing agents. In 1986, Nippon Shokubai Co., Ltd. pioneered the development of polycarboxylate-based high-efficiency water-reducing agents with a certain proportion of hydrophilic functional groups. Subsequently, it was gradually applied in concrete engineering. After 1995, the usage of polycarboxylate-based high-efficiency water-reducing agents in Japan reached 80% of all water-reducing agent usage, and it was included in the JISA6024 national standard in 1995. Since the mid-1990s, many universities and research institutes in my country have conducted extensive research on polycarboxylate high-performance water-reducing agents and achieved certain results. Currently, polycarboxylate water-reducing agents are used in all large-scale key projects, playing an irreplaceable role in engineering construction, and their application is gradually expanding from high-strength, special-function concrete to ordinary concrete.
[0003] However, current high-performance polycarboxylate superplasticizers generally suffer from common problems such as sensitivity to the mud and stone powder content of sand and gravel, poor adaptability, rapid loss of fluidity over time, difficulty in long-distance transportation and pumping, and segregation of oozing water, which restrict their further application. Summary of the Invention
[0004] The technical problem to be solved by the present invention is to provide a highly adaptable water-retaining polycarboxylate superplasticizer mother liquor that effectively improves concrete bleeding and enhances concrete workability.
[0005] Another technical problem to be solved by the present invention is to provide a method for preparing the mother liquor of the highly adaptable water-retaining polycarboxylate superplasticizer.
[0006] To solve the above problems, the present invention provides a highly adaptable water-retaining polycarboxylate superplasticizer mother liquor, characterized in that: the polycarboxylate superplasticizer mother liquor is composed of four components: a base solution, a component A solution, a component B solution, and a component C solution; the base solution is composed of the following raw materials in parts by weight: 3-4 parts of 32% liquid alkali, 200-300 parts of ethylene glycol monovinyl polyethylene glycol ether, 50-100 parts of modified starch, 2-3.5 parts of 28% hydrogen peroxide, and 0.8-1.5 parts of 1% sulfite. The solution comprises an iron solution and 320-380 parts water; the A solution is composed of the following raw materials in parts by weight: 0.4-0.8 parts reducing agent, 0.8-1.2 parts chain transfer agent and 90-110 parts water; the B solution is composed of the following raw materials in parts by weight: 0.3-0.6 parts polymerization inhibitor, 7-10 parts isomeric ester, 25-35 parts acrylic acid and 50-75 parts water; the C solution is composed of the following raw materials in parts by weight: 2-4 parts caustic soda flakes, 8-12 parts triethanolamine, 1-3 parts hydroxypropyl methylcellulose and 30-60 parts water.
[0007] The modified starch is one or both of hydroxypropyl sodium hypochlorite oxidized starch (O-HPS) and hydroxypropyl peroxide oxidized starch (HP-OS).
[0008] The sodium hydroxypropyl hypochlorite oxidized starch (O-HPS) was prepared by the following method: 90% ethanol was added to cassava starch to prepare a 40% homogeneous starch slurry; solid NaOH was added to the starch slurry, nitrogen gas was introduced, and then PO (polyolefin copolymer) was added. The mixture was reacted at 55°C for 16 h, and the pH of the starch slurry was adjusted to 8.5 with 18% HCl; then NaClO3 was added, and the pH of the starch slurry was maintained at 8.5 with 3% NaOH solution. The mixture was then reacted at 40°C for 2 hours. After h, the pH of the starch milk was adjusted to 6.5 to stop the reaction. The reacted starch milk was then subjected to suction filtration and washing with 90% ethanol to obtain a filter cake. The filter cake was dried, pulverized, and passed through a 120-150 mesh sieve to obtain sodium hydroxypropyl hypochlorite oxidized starch. The amount of NaOH used was 3.2% of the mass of the cassava starch; the amount of PO used was 40% of the mass of the cassava starch; and the amount of NaClO3 used was 30% of the mass of the cassava starch.
[0009] The hydroxypropyl peroxide-coated starch (HP-OS) was prepared by the following method: 90% ethanol was added to cassava starch to prepare a 40% homogeneous starch slurry; solid NaOH was added to the starch slurry, nitrogen gas was introduced, and then PO (polyolefin copolymer) was added. The mixture was reacted at 45°C for 16 h, and the pH of the starch slurry was adjusted to 8.5 with 18% HCl; then CuSO4 and H2O2 were added, and the pH of the starch slurry was maintained at 7.5 with 3% NaOH solution. After reacting at 45°C for another 2 h, the pH of the starch slurry was adjusted to 6.5. The reaction is stopped; the starch milk after the reaction is successively filtered and washed with 90% ethanol to obtain a filter cake; the filter cake is dried, crushed, and passed through a 120-150 mesh sieve to obtain hydroxypropyl peroxide starch; the amount of NaOH used is 3.2% of the mass of the cassava starch; the amount of PO used is 40% of the mass of the cassava starch; the amount of CuSO4 used is 0.03% of the mass of the cassava starch; and the amount of H2O2 used is 2% of the mass of the cassava starch.
[0010] The reducing agent is E51 or Vc.
[0011] The chain transfer agent is mercaptoethanol or mercaptopropionic acid.
[0012] The polymerization inhibitor is a 2% (w / w) aqueous solution of p-hydroxyanisole.
[0013] The isomeric ester refers to polyethylene glycol methacrylate with a molecular weight of 350, or a copolyether of 2-methylepoxypropane and 1,2-propanediol mono(2-methyl-2-acrylate) with a molecular weight of 1000.
[0014] The viscosity of the hydroxypropyl methylcellulose is 300~500 cps.
[0015] The preparation method of the mother liquor of a highly adaptable water-retaining polycarboxylate superplasticizer as described above includes the following steps: (1) Weigh according to the proportions; (2) At room temperature, ethylene glycol monovinyl polyethylene glycol ether and modified starch are mixed with water and stirred for 40-60 minutes to dissolve. Then, liquid alkali is added and stirred for 10 minutes. Hydrogen peroxide is added and stirred for another 3 minutes. Ferrous sulfate solution is then added to obtain the base solution. (3) Add the reducing agent and chain transfer agent to water in sequence and stir to dissolve to obtain solution A; add the polymerization inhibitor, isomeric ester and acrylic acid to water in sequence and stir to dissolve to obtain solution B; add caustic soda, hydroxypropyl methylcellulose and triethanolamine to water in sequence and stir to dissolve to obtain solution C. (4) Simultaneously and uniformly add the A solution and the B solution to the base solution, with the A solution added for 60 minutes and the B solution added for 50 minutes, allowing for natural reaction without interfering with the reaction temperature; after the solution is added, keep it warm and stir for 1-2 hours, then add the C solution and stir evenly to obtain the polycarboxylate superplasticizer mother liquor.
[0016] Compared with the prior art, the present invention has the following advantages: 1. In this invention, a portion of the polycarboxylic acid molecular backbone is introduced. The introduction of the isomeric ester replaces part of the original acrylic acid backbone. The steric hindrance effect between cement particles is increased after modification by the isomeric ester. The addition of the isomeric ester can increase the surface adsorption of polycarboxylic acid water-reducing agent molecules on calcium silicate hydrate, which is beneficial to improving the adsorption of water-reducing agent on the surface of calcium silicate hydrate, significantly improving the adaptability and workability of polycarboxylic acid water-reducing agent.
[0017] 2. The ester groups in the isomeric ester molecule structure added in this invention can undergo a certain degree of hydrolysis and slow release, effectively improving the slump retention performance of concrete and reducing the loss of fluidity over time. At the same time, the addition of isomeric esters can also enhance the reaction efficiency of polyether and unsaturated carboxylic acid.
[0018] 3. This invention uses modified hydroxypropyl sodium hypochlorite oxidized starch and hydroxypropyl peroxide oxidized starch as the components of the water-reducing agent mother liquor, which have good water retention and encapsulation properties in concrete. At the same time, low-viscosity hydroxypropyl methylcellulose is introduced to make the concrete mixture have better adhesion, thus comprehensively solving the problem of easy bleeding of EPEG type polycarboxylate water-reducing agent mother liquor in concrete.
[0019] 4. This invention introduces triethanolamine into the water-reducing agent mother liquor component, which effectively increases the early strength of the hardened concrete and makes up for the defect of low early strength of polycarboxylate water-reducing agents with slow-release effect in concrete.
[0020] 5. In preparing hydroxypropyl sodium hypochlorite oxidized starch and hydroxypropyl peroxide oxidized starch, this invention uses cassava starch, which is widely available, renewable, and inexpensive, thus effectively reducing costs and carbon emissions.
[0021] 6. The present invention uses modified starch and isomeric esters, which can effectively replace 20-30% of ethylene glycol monovinyl polyethylene glycol ether macromonomers, thereby reducing the use of petrochemical products in the mother liquor of polycarboxylate superplasticizer. Detailed Implementation
[0022] A highly adaptable water-retaining polycarboxylate superplasticizer mother liquor, which is composed of four components: base solution, component A solution, component B solution and component C solution.
[0023] The base solution is composed of the following raw materials in parts by weight (g): 3-4 parts of 32% liquid alkali, 200-300 parts of ethylene glycol monovinyl polyethylene glycol ether (EPEG-3000), 50-100 parts of modified starch, 2-3.5 parts of 28% hydrogen peroxide, 0.8-1.5 parts of 1% ferrous sulfate solution, and 320-380 parts of water.
[0024] Solution A is composed of the following raw materials in parts by weight (g): 0.4 to 0.8 parts reducing agent, 0.8 to 1.2 parts chain transfer agent, and 90 to 110 parts water.
[0025] Solution B is composed of the following raw materials in parts by weight (g): 0.3-0.6 parts polymerization inhibitor, 7-10 parts isomeric ester, 25-35 parts acrylic acid and 50-75 parts water.
[0026] The C-material solution is composed of the following raw materials in parts by weight (g): 2-4 parts caustic soda flakes, 8-12 parts triethanolamine, 1-3 parts hydroxypropyl methylcellulose, and 30-60 parts water.
[0027] The modified starch is one or both of hydroxypropyl sodium hypochlorite oxidized starch (O-HPS) and hydroxypropyl peroxide oxidized starch (HP-OS).
[0028] Hydroxypropyl sodium hypochlorite oxidized starch (O-HPS) was prepared by the following method: 90% ethanol was added to cassava starch to prepare a 40% homogeneous starch slurry; solid NaOH was added to the starch slurry, nitrogen gas was introduced, and then PO (polyolefin copolymer) was added. The mixture was reacted at 55°C for 16 h, and the pH of the starch slurry was adjusted to 8.5 with 18% HCl; then NaClO3 was added, and the pH of the starch slurry was maintained at 8.5 with 3% NaOH solution, and the mixture was reacted at 40°C for 2 hours. After h, the pH of the starch milk was adjusted to 6.5 to stop the reaction. The reacted starch milk was then subjected to suction filtration and washing with 90% ethanol to obtain a filter cake. The filter cake was dried in a 55℃ forced-air drying oven, then pulverized and passed through a 120-150 mesh sieve to obtain sodium hydroxypropyl hypochlorite oxidized starch. The amount of NaOH used was 3.2% of the mass of cassava starch; the amount of PO was 40% of the mass of cassava starch; and the amount of NaClO3 was 30% of the mass of cassava starch.
[0029] Hydroxypropyl peroxide starch (HP-OS) was prepared by the following method: 90% ethanol was added to cassava starch to prepare a 40% homogeneous starch slurry; solid NaOH was added to the starch slurry, nitrogen gas was introduced, and then PO (polyolefin copolymer) was added. The mixture was reacted at 45°C for 16 h, and the pH of the starch slurry was adjusted to 8.5 with 18% HCl; then CuSO4 and H2O2 were added, and the pH of the starch slurry was maintained at 7.5 with 3% NaOH solution. The mixture was then reacted at 45°C for another 2 h, and the pH of the starch slurry was adjusted to 6.5. The reaction was stopped; the starch milk after the reaction was successively filtered and washed with 90% ethanol to obtain filter cake; the filter cake was dried in a 55℃ forced-air drying oven, then crushed and passed through a 120-150 mesh sieve to obtain hydroxypropyl peroxide starch; the amount of NaOH used was 3.2% of the mass of cassava starch; the amount of PO used was 40% of the mass of cassava starch; the amount of CuSO4 used was 0.03% of the mass of cassava starch; and the amount of H2O2 used was 2% of the mass of cassava starch.
[0030] The reducing agent is E51 or Vc.
[0031] The chain transfer agent is mercaptoethanol or mercaptopropionic acid.
[0032] The polymerization inhibitor is a 2% (w / w) aqueous solution of p-hydroxyanisole.
[0033] Isomeric esters refer to polyethylene glycol methacrylate with a molecular weight of 350, or a coether of 2-methylepoxypropane and 1,2-propanediol mono(2-methyl-2-acrylate) with a molecular weight of 1000.
[0034] The viscosity of hydroxypropyl methylcellulose is 300~500 cps.
[0035] The preparation method of this highly adaptable water-retaining polycarboxylate superplasticizer mother liquor includes the following steps: (1) Weigh according to the proportions; (2) At room temperature, ethylene glycol monovinyl polyethylene glycol ether and modified starch are mixed with water and stirred for 40-60 minutes to dissolve. Then, liquid alkali is added and stirred for 10 minutes. Hydrogen peroxide is added and stirred for another 3 minutes. Ferrous sulfate solution is then added to obtain the base solution. (3) Add the reducing agent and chain transfer agent to water in sequence and stir to dissolve to obtain solution A; add the polymerization inhibitor, isomeric ester and acrylic acid to water in sequence and stir to dissolve to obtain solution B; add caustic soda, hydroxypropyl methylcellulose and triethanolamine to water in sequence and stir to dissolve to obtain solution C. (4) Simultaneously and uniformly add solution A and solution B to the base solution, with solution A added for 60 minutes and solution B added for 50 minutes, allowing the reaction to proceed naturally without interfering with the reaction temperature; after the solution addition is complete, keep it warm and stir for 1-2 hours, then add solution C and stir until homogeneous to obtain the polycarboxylate superplasticizer mother liquor.
[0036] Example 1 S1 Preparation of hydroxypropyl sodium hypochlorite oxidized starch (O-HPS): 90% ethanol was added to 100g of cassava starch to prepare a 40% homogeneous starch slurry. 3.2% solid NaOH was added to the starch slurry, nitrogen gas was introduced, and then 40% PO was added. The mixture was reacted at 55℃ for 16 h, and the pH of the starch slurry was adjusted to 8.5 with 18% HCl. Then, 30% NaClO3 (by weight of cassava starch) was added, and the pH of the starch slurry was maintained at 8.5 with 3% NaOH solution. The mixture was reacted at 40℃ for another 2 h, and then the pH of the starch slurry was adjusted to 6.5 to stop the reaction. The reacted starch slurry was then filtered and washed with 90% ethanol to obtain a filter cake. The filter cake was dried in a 55℃ forced-air drying oven, pulverized, and passed through a 150-mesh sieve to obtain sodium hydroxypropyl hypochlorite oxidized starch.
[0037] S2 Preparation of Mother Liquor for Highly Adaptable Water-Retaining Polycarboxylate Superplasticizer: At room temperature, mix 270g of ethylene glycol monovinyl polyethylene glycol ether, 80g of sodium hydroxypropyl hypochlorite oxidized starch with 350g of water and stir for 40-60 minutes at a speed of 180r / min. Then add 4g of 32% liquid alkali and stir for 10 minutes. After stirring, add 3g of 28% hydrogen peroxide and stir for another 3 minutes. Finally, add 1g of 1% ferrous sulfate solution to obtain the base solution.
[0038] Add 0.6g of E51 and 1g of mercaptoethanol to 100g of water and stir to dissolve, thus obtaining solution A.
[0039] Add 0.5g of 2% p-hydroxyanisole aqueous solution, 7g of polyethylene glycol methacrylate, and 30g of acrylic acid sequentially to 70g of water and stir to dissolve, thus obtaining solution B.
[0040] Add 3g of caustic soda flakes, 2g of hydroxypropyl methylcellulose, and 10g of triethanolamine to 38g of water and stir to dissolve, thus obtaining solution C.
[0041] Simultaneously and uniformly add solution A and solution B to the base solution, with solution A added for 60 minutes and solution B added for 50 minutes, allowing the reaction to proceed naturally without interfering with the reaction temperature; after the solution addition is complete, keep the temperature and stir for 1 hour, then add solution C and stir until homogeneous to obtain the polycarboxylate superplasticizer mother liquor.
[0042] Example 2 S1 Preparation of hydroxypropyl peroxide starch (HP-OS): 90% ethanol was added to 100g of cassava starch to prepare a 40% homogeneous starch slurry. 3.2% solid NaOH was added to the starch slurry, nitrogen gas was introduced, and then 40% PO was added. The mixture was reacted at 45℃ for 16 h, and the pH of the starch slurry was adjusted to 8.5 with 18% HCl. Then, 0.03% CuSO4 and 2% H2O2 were added, and the pH of the starch slurry was maintained at 7.5 with 3% NaOH solution. The mixture was reacted at 45℃ for another 2 h, and then the pH of the starch slurry was adjusted to 6.5 before the reaction was stopped. The reacted starch slurry was then filtered and washed with 90% ethanol to obtain a filter cake. The filter cake was dried in a 55℃ forced-air drying oven, pulverized, and passed through a 150-mesh sieve to obtain hydroxypropyl peroxide starch.
[0043] S2 Preparation of Mother Liquor for Highly Adaptable Water-Retaining Polycarboxylate Superplasticizer: At room temperature, mix 250g of ethylene glycol monovinyl polyethylene glycol ether and 70g of hydroxypropyl starch peroxide with 350g of water and stir for 40-60 minutes at a speed of 180r / min. Then add 3.5g of 32% liquid alkali and stir for 10 minutes. After stirring, add 3.2g of 28% hydrogen peroxide and stir for another 3 minutes. Finally, add 1g of 1% ferrous sulfate solution to obtain the base solution.
[0044] Add 0.7g of vitamin C and 1.2g of mercaptopropionic acid sequentially to 100g of water and stir to dissolve, thus obtaining solution A.
[0045] 0.6g of 2% p-hydroxyanisole aqueous solution, 10g of 2-methylepoxypropane with a molecular weight of 1000 and a co-ether of 1,2-propanediol mono(2-methyl-2-acrylate), and 32g of acrylic acid were sequentially added to 70g of water and stirred to dissolve, thus obtaining solution B.
[0046] Add 2.5g of caustic soda flakes, 3g of hydroxypropyl methylcellulose, and 11g of triethanolamine to 38g of water and stir to dissolve, thus obtaining solution C.
[0047] Simultaneously and uniformly add solution A and solution B to the base solution, with solution A added for 60 minutes and solution B added for 50 minutes, allowing the reaction to proceed naturally without interfering with the reaction temperature; after the solution addition is complete, keep the temperature and stir for 1 hour, then add solution C and stir until homogeneous to obtain the polycarboxylate superplasticizer mother liquor.
[0048] The polycarboxylate superplasticizer mother liquors prepared in Examples 1 and 2 were compared with commercially available mother liquor products 181 and 173-L. Both 181 and 173-L mother liquors were purchased from Lanzhou Hongfang New Building Materials Technology Co., Ltd. The workability indicators of the different mother liquors in C30 concrete were tested using a 7% aqueous solution at the reduced solids level. The results, based on GB8076-2008 "Concrete Admixtures", are shown in Table 1. Table 1 As shown in Table 1, the polycarboxylate superplasticizer mother liquor prepared in Examples 1 and 2 showed significantly improved adaptability to changes in concrete water content and admixture dosage, significantly improved concrete workability and the coating of the paste on sand and gravel aggregates, effectively improved concrete bleeding, and significantly enhanced concrete workability.
[0049] The above description is merely a preferred embodiment of the present invention, and therefore should not be construed as limiting the scope of the present invention. All equivalent changes and modifications made in accordance with the scope of the patent and the contents of the specification should still fall within the scope of the present invention.
Claims
1. A highly adaptable water-retaining polycarboxylate superplasticizer mother liquor, characterized in that: The polycarboxylate superplasticizer mother liquor consists of four components: a base solution, component A solution, component B solution, and component C solution. The base solution comprises the following raw materials in parts by weight: 3-4 parts of 32% liquid alkali, 200-300 parts of ethylene glycol monovinyl polyethylene glycol ether, 50-100 parts of modified starch, 2-3.5 parts of 28% hydrogen peroxide, 0.8-1.5 parts of 1% ferrous sulfate solution, and 320-380 parts of water. The component A solution... The liquid is composed of the following raw materials in parts by weight: 0.4-0.8 parts reducing agent, 0.8-1.2 parts chain transfer agent, and 90-110 parts water; the B component solution is composed of the following raw materials in parts by weight: 0.3-0.6 parts polymerization inhibitor, 7-10 parts isomeric ester, 25-35 parts acrylic acid, and 50-75 parts water; the C component solution is composed of the following raw materials in parts by weight: 2-4 parts caustic soda flakes, 8-12 parts triethanolamine, 1-3 parts hydroxypropyl methylcellulose, and 30-60 parts water.
2. The highly adaptable water-retaining polycarboxylate superplasticizer mother liquor as described in claim 1, characterized in that: The modified starch is one or both of hydroxypropyl sodium hypochlorite oxidized starch and hydroxypropyl peroxide oxidized starch.
3. The highly adaptable water-retaining polycarboxylate superplasticizer mother liquor as described in claim 2, characterized in that: The sodium hydroxypropyl hypochlorite oxidized starch is prepared by the following method: 90% ethanol is added to cassava starch to prepare a 40% homogeneous starch slurry; solid NaOH is added to the starch slurry, nitrogen gas is introduced, and then PO is added. The mixture is reacted at 55°C for 16 h, and the pH of the starch slurry is adjusted to 8.5 with 18% HCl; then NaClO3 is added, and the pH of the starch slurry is maintained at 8.5 with 3% NaOH solution. The mixture is then reacted at 40°C for 2 h, and the pH of the starch slurry is adjusted to 6.5 to stop the reaction; the reacted starch slurry is then filtered and washed with 90% ethanol to obtain a filter cake; the filter cake is dried, pulverized, and passed through a 120-150 mesh sieve to obtain sodium hydroxypropyl hypochlorite oxidized starch; the amount of NaOH used is 3.2% of the mass of the cassava starch; the amount of PO used is 40% of the mass of the cassava starch; and the amount of NaClO3 used is 30% of the mass of the cassava starch.
4. The highly adaptable water-retaining polycarboxylate superplasticizer mother liquor as described in claim 2, characterized in that: The hydroxypropyl peroxide-coated starch was prepared by the following method: 90% ethanol was added to cassava starch to prepare a 40% homogeneous starch slurry; solid NaOH was added to the starch slurry, nitrogen gas was introduced, and then PO was added. The mixture was reacted at 45°C for 16 h, and the pH of the starch slurry was adjusted to 8.5 with 18% HCl; then CuSO4 and H2O2 were added, and the pH of the starch slurry was maintained at 7.5 with 3% NaOH solution. After reacting at 45°C for another 2 h, the pH of the starch slurry was adjusted to 6.
5. The reaction is stopped; the starch milk after the reaction is successively filtered and washed with 90% ethanol to obtain a filter cake; the filter cake is dried, crushed, and passed through a 120-150 mesh sieve to obtain hydroxypropyl peroxide starch; the amount of NaOH used is 3.2% of the mass of the cassava starch; the amount of PO used is 40% of the mass of the cassava starch; the amount of CuSO4 used is 0.03% of the mass of the cassava starch; and the amount of H2O2 used is 2% of the mass of the cassava starch.
5. The highly adaptable water-retaining polycarboxylate superplasticizer mother liquor as described in claim 1, characterized in that: The reducing agent is E51 or Vc.
6. The highly adaptable water-retaining polycarboxylate superplasticizer mother liquor as described in claim 1, characterized in that: The chain transfer agent is mercaptoethanol or mercaptopropionic acid.
7. The highly adaptable water-retaining polycarboxylate superplasticizer mother liquor as described in claim 1, characterized in that: The polymerization inhibitor is a 2% (w / w) aqueous solution of p-hydroxyanisole.
8. The highly adaptable water-retaining polycarboxylate superplasticizer mother liquor as described in claim 1, characterized in that: The isomeric ester refers to polyethylene glycol methacrylate with a molecular weight of 350, or a copolyether of 2-methylepoxypropane and 1,2-propanediol mono(2-methyl-2-acrylate) with a molecular weight of 1000.
9. The highly adaptable water-retaining polycarboxylate superplasticizer mother liquor as described in claim 1, characterized in that: The viscosity of the hydroxypropyl methylcellulose is 300~500 cps.
10. A method for preparing a highly adaptable water-retaining polycarboxylate superplasticizer mother liquor according to any one of claims 1 to 9, comprising the following steps: (1) Weigh according to the proportions; (2) At room temperature, ethylene glycol monovinyl polyethylene glycol ether and modified starch are mixed with water and stirred for 40-60 minutes to dissolve. Then, liquid alkali is added and stirred for 10 minutes. Hydrogen peroxide is added and stirred for another 3 minutes. Ferrous sulfate solution is then added to obtain the base solution. (3) Add the reducing agent and chain transfer agent to water in sequence and stir to dissolve to obtain solution A; add the polymerization inhibitor, isomeric ester and acrylic acid to water in sequence and stir to dissolve to obtain solution B; add caustic soda, hydroxypropyl methylcellulose and triethanolamine to water in sequence and stir to dissolve to obtain solution C. (4) Simultaneously and uniformly add the A solution and the B solution to the base solution, with the A solution added for 60 minutes and the B solution added for 50 minutes, allowing for natural reaction without interfering with the reaction temperature; after the solution is added, keep it warm and stir for 1-2 hours, then add the C solution and stir evenly to obtain the polycarboxylate superplasticizer mother liquor.