CN112920346A - Preparation method of modified polycarboxylate superplasticizer for claystone concrete - Google Patents
Preparation method of modified polycarboxylate superplasticizer for claystone concrete Download PDFInfo
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- C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
- C08F283/00—Macromolecular compounds obtained by polymerising monomers on to polymers provided for in subclass C08G
- C08F283/06—Macromolecular compounds obtained by polymerising monomers on to polymers provided for in subclass C08G on to polyethers, polyoxymethylenes or polyacetals
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- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B24/00—Use of organic materials as active ingredients for mortars, concrete or artificial stone, e.g. plasticisers
- C04B24/24—Macromolecular compounds
- C04B24/26—Macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds
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- C08G65/00—Macromolecular compounds obtained by reactions forming an ether link in the main chain of the macromolecule
- C08G65/02—Macromolecular compounds obtained by reactions forming an ether link in the main chain of the macromolecule from cyclic ethers by opening of the heterocyclic ring
- C08G65/26—Macromolecular compounds obtained by reactions forming an ether link in the main chain of the macromolecule from cyclic ethers by opening of the heterocyclic ring from cyclic ethers and other compounds
- C08G65/2603—Macromolecular compounds obtained by reactions forming an ether link in the main chain of the macromolecule from cyclic ethers by opening of the heterocyclic ring from cyclic ethers and other compounds the other compounds containing oxygen
- C08G65/2615—Macromolecular compounds obtained by reactions forming an ether link in the main chain of the macromolecule from cyclic ethers by opening of the heterocyclic ring from cyclic ethers and other compounds the other compounds containing oxygen the other compounds containing carboxylic acid, ester or anhydride groups
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- C08G65/00—Macromolecular compounds obtained by reactions forming an ether link in the main chain of the macromolecule
- C08G65/02—Macromolecular compounds obtained by reactions forming an ether link in the main chain of the macromolecule from cyclic ethers by opening of the heterocyclic ring
- C08G65/26—Macromolecular compounds obtained by reactions forming an ether link in the main chain of the macromolecule from cyclic ethers by opening of the heterocyclic ring from cyclic ethers and other compounds
- C08G65/2642—Macromolecular compounds obtained by reactions forming an ether link in the main chain of the macromolecule from cyclic ethers by opening of the heterocyclic ring from cyclic ethers and other compounds characterised by the catalyst used
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- C08G65/00—Macromolecular compounds obtained by reactions forming an ether link in the main chain of the macromolecule
- C08G65/02—Macromolecular compounds obtained by reactions forming an ether link in the main chain of the macromolecule from cyclic ethers by opening of the heterocyclic ring
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- C04B2103/00—Function or property of ingredients for mortars, concrete or artificial stone
- C04B2103/30—Water reducers, plasticisers, air-entrainers, flow improvers
- C04B2103/302—Water reducers
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Abstract
The invention discloses a preparation method of a modified polycarboxylate superplasticizer for claystone concrete, which comprises the following steps: preparing a third monomer intermediate; preparing a third monomer; and thirdly, synthesizing the modified polycarboxylic acid water reducing agent. The invention provides a preparation method of a modified polycarboxylate superplasticizer for claystone concrete, which comprises the steps of carrying out ring-opening polymerization on maleic anhydride serving as an initiator, epoxide and epichlorohydrin in two steps to generate an intermediate of a maleic anhydride structure, grafting an amino acid containing a benzene ring or a heterocyclic ring structure to the tail end of the intermediate to prepare a functional third monomer with a carboxyl-terminated end and a rigid structure, and copolymerizing the functional third monomer with acrylic acid and a polycarboxylate superplasticizer polyether macromonomer to prepare the modified PCE with high tolerance to clay in claystone. Due to the existence of the third monomer carboxyl end capping and the benzene ring or heterocycle in the structure, on the basis of keeping the original performance of the conventional PCE, the electrostatic repulsion effect and the steric hindrance effect of the side chain of the third monomer are improved, the surface and intercalation adsorption effect of clay such as kaolin, montmorillonite and the like on the PCE is reduced, the tolerance of the PCE on the clay is improved, and the negative effect of the clay on the dispersion performance of the PCE is reduced.
Description
Technical Field
The invention belongs to the technical field of synthesis of polycarboxylic acid water reducing agents, and relates to a preparation method of a modified polycarboxylic acid water reducing agent for claystone concrete.
Background
Currently, the development process of the water reducing agent is generally considered to be divided into three stages in the industry: the first stage is a common water reducing agent stage represented by calcium lignosulfonate; the second stage is a high-efficiency water reducing agent stage represented by a naphthalene water reducing agent; the third stage is a high-performance water reducing agent stage represented by a polycarboxylic acid water reducing agent (PCE). The polycarboxylate superplasticizer not only has the effects of improving the pore structure of a concrete system, improving the compactness of concrete, efficiently reducing water and the like, but also has the advantages of good dispersibility, small addition amount, small slump loss and the like compared with other superplasticizers, so that the PCE comprehensively replaces the first two generations of superplasticizers and is widely applied.
On one hand, in scientific experiments and daily production at the present stage, people find that when the PCE is used in claystone concrete, the PCE is influenced by clay in a concrete system, and further the working performance is reduced, wherein the PCE is influenced by kaolin and montmorillonite components in the clay particularly obviously; on the other hand, with the vigorous development of the infrastructure industry, the reserves of high-quality mineral raw materials are gradually reduced, and the use of claystone as concrete aggregate is also increased, so that the improvement of the tolerance of the PCE in a claystone concrete system is already the key point of research in the next stage of the PCE, and the research and development and synthesis of the modified polycarboxylic acid water reducing agent for claystone concrete are urgent.
Disclosure of Invention
The invention aims to provide a preparation method of a modified polycarboxylate superplasticizer for claystone concrete, which can effectively overcome the defects of the existing polycarboxylate superplasticizer when used in claystone concrete.
The technical scheme adopted by the invention is as follows: the preparation method comprises the following steps:
preparation of a third monomer intermediate: adding melted maleic anhydride into a reaction kettle, and adding a proper amount of KOH and 18-crown-6 serving as a cocatalyst according to a certain ratio; sealing the kettle and replacing the kettle by high-purity nitrogen for more than three times; raising the temperature, keeping the temperature of the reaction kettle at 115-plus-120 ℃, introducing a small amount of epoxide, controlling the pressure to be not higher than 0.1MPa for primary initiation, after the reaction initiation is successful, raising the reaction temperature to 125-plus-135 ℃, controlling the reaction pressure to be not higher than 0.6MPa, finishing the rest epoxide, and curing for 1.5h after the feeding is finished; after curing, degassing and neutralizing to obtain a third monomer intermediate;
preparing a third monomer: adding the third monomer intermediate obtained in the step I into a reaction kettle, adding a phase transfer catalyst, sealing the kettle, replacing for more than three times by using high-purity nitrogen, dropwise adding epoxy chloropropane for carrying out ring opening reaction for 4-5h at the temperature of 50-60 ℃, adding amino acid for carrying out reaction for 2-3h at the temperature of 40-50 ℃ under the protection of nitrogen after the reaction is completed, and obtaining a third monomer;
thirdly, synthesizing the modified polycarboxylic acid water reducing agent: adding a polyether macromonomer and deionized water into a container, and stirring and dissolving for later use; preparing a material A: dissolving a certain amount of acrylic acid and a third monomer in deionized water; preparing a material B: dissolving a certain amount of ascorbic acid (Vc) and mercaptopropionic acid in deionized water; adding a certain amount of hydrogen peroxide into a container, dripping A, B materials after 2-3min, controlling the dripping time of A, B materials at 2-3h, keeping the temperature for 1.5h after finishing dripping, cooling, and adding NaOH solution with the mass concentration of 30% into the container to adjust the pH to be neutral, thus obtaining the product.
The dosage of KOH used in the step I is 0.05-0.50 percent of the total mass of reactants, preferably 0.10-0.30 percent, and the molar ratio of KOH to the cocatalyst 18-crown ether-6 is 1: 0.2-0.3.
In the first step, the introduced epoxide is a mixture of ethylene oxide and propylene oxide, and the initiation amount is not more than 5% of the total feeding amount; wherein the mass ratio of the propylene oxide to the ethylene oxide is 1:0.7-3.8, preferably 1: 1.6-1.7.
In the step I, the mass ratio of the maleic anhydride to the epoxide is 1: 2.6-4.1.
The degassing time in the step I is 20-90min, the temperature is 90-115 ℃, the preferred degassing time is 45-60min, and the temperature is 95-110 ℃.
The neutralization time in the step I is 10-90min, the temperature is 70-90 ℃, preferably the neutralization time is 30-40min, and the temperature is 70-80 ℃.
The acid used in the neutralization in the step I is one or more of citric acid, glacial acetic acid and benzoic acid, preferably glacial acetic acid, and the pH value of the system after the neutralization is 6.50-7.00.
The molecular weight of the third monomer intermediate in the step (i) is 350-500.
The amino acid used in the second step is one or more of histidine (His), tryptophan (Trp) and tyrosine (Tyr).
In the step II, the molar ratio of the third monomer intermediate to the epichlorohydrin to the amino acid is 1: 1.05: 1.15.
the phase transfer catalyst in the step (II) is one or more of triethyl ammonium chloride, tetrabutyl ammonium chloride, methyl trioctyl ammonium chloride and tetrabutyl ammonium hydrogen sulfate, and the dosage of the phase transfer catalyst is 0.5 to 2.0 percent of the total mass of reactants, and the preferred dosage is 1.0 to 1.8 percent.
In the step (c), the polyether macromonomer is one or more of methoxy polyethylene glycol acrylate and methoxy polyethylene glycol methacrylate, and the molecular weight is 1500-.
In the third step, the dosage of the ascorbic acid is 0.1 to 0.3 percent of the mass of the polyether macromonomer, the dosage of the mercaptopropionic acid is 0.2 to 0.4 percent of the mass of the polyether macromonomer, and the dosage of the hydrogen peroxide is 1.0 to 3.0 percent of the mass of the polyether macromonomer.
In the step (c), the molar ratio of the acrylic acid to the third monomer to the polyether macromonomer is 2.5:1: 1.5.
The solid content of the modified polycarboxylate superplasticizer for claystone concrete obtained in the third step is 40-60%.
The invention provides a preparation method of a modified polycarboxylate superplasticizer for claystone concrete, which comprises the steps of carrying out ring-opening polymerization on maleic anhydride serving as an initiator, epoxide and epichlorohydrin in two steps to generate an intermediate of a maleic anhydride structure, grafting an amino acid containing a benzene ring or a heterocyclic ring structure to the tail end of the intermediate to prepare a functional third monomer with a carboxyl-terminated end and a rigid structure, and copolymerizing the functional third monomer with acrylic acid and a polycarboxylate superplasticizer polyether macromonomer to prepare the modified PCE with high tolerance to clay in claystone. Due to the existence of the third monomer carboxyl end capping and the benzene ring or heterocycle in the structure, on the basis of keeping the original performance of the conventional PCE, the electrostatic repulsion effect and the steric hindrance effect of the side chain of the third monomer are improved, the surface and intercalation adsorption effect of clay such as kaolin, montmorillonite and the like on the PCE is reduced, the tolerance of the PCE on the clay is improved, and the negative effect of the clay on the dispersion performance of the PCE is reduced.
The invention has the advantages that:
1. according to the invention, a process of reacting maleic anhydride with mixed materials of ethylene oxide and propylene oxide is adopted in the synthesis process of the third monomer intermediate, and the water reducer mother liquor synthesized by the third monomer obtained by the process has improved compatibility with other additives and is still excellent in workability and adaptability of a clay-containing concrete system.
2. In the invention, 18-crown ether-6 is introduced as a cocatalyst in the synthesis process of the third monomer intermediate, and the adoption of the cocatalyst effectively shortens the polymerization reaction time of maleic anhydride and epoxide.
3. The modified PCE is synthesized by adopting the third monomer, acrylic acid and polyether macromonomer, and on the basis of keeping the original performance of the PCE, the adsorption capacity of the prepared modified PCE on clay is reduced by 30-35% and the initial fluidity of neat paste is increased by 18-21% compared with the conventional product due to the introduction of the third monomer.
4. The synthesis method provided by the invention has the advantages of simple process, convenience in operation, shorter reaction period and excellent product performance, and has great significance for popularization and application of claystone concrete.
Detailed Description
Example 1:
preparation of a third monomer intermediate: adding 150g of maleic anhydride into a reaction kettle after melting, and then adding 0.54g of KOH and 0.51g of cocatalyst 18-crown-6; sealing the kettle and replacing the kettle by high-purity nitrogen for three times; raising the temperature, keeping the temperature of the reaction kettle at 115-120 ℃, introducing 20g of epoxide, and controlling the pressure not to be higher than 0.1MPa to initiate a reaction primarily; after the reaction initiation is successful, raising the reaction temperature to 135 ℃ at 125-; after curing, the mixture was degassed and neutralized with 0.57g glacial acetic acid to obtain 670g of a third monomer intermediate having a molecular weight of 441.
Preparing a third monomer: adding 500g of the third monomer intermediate obtained in the step I into a reaction kettle, and adding 4.06g of methyl trioctyl ammonium chloride; sealing the kettle, replacing the kettle by high-purity nitrogen for more than three times, and dropwise adding 110g of epoxy chloropropane for carrying out ring-opening reaction for 4-5h at the temperature of 50-60 ℃; when the reaction is completed, 202g of histidine is added under the protection of nitrogen to maintain the temperature of 40-50 ℃ and react for 2-3h to obtain 800g of a third monomer with the molecular weight of 652.
Thirdly, synthesizing the modified polycarboxylic acid water reducing agent: 360g of 2400-molecular-weight methoxypolyethylene glycol acrylate and 300g of deionized water are added into a four-neck flask, and stirred and dissolved for later use. Preparing a material A: 18g of acrylic acid and 65.2g of the third monomer were dissolved in 100g of deionized water. Preparing a material B: 0.54g of ascorbic acid (Vc) and 1.01g of mercaptopropionic acid were dissolved in 100g of deionized water. A four-necked flask was charged with 5.76g of hydrogen peroxide (H)2O2) And A, B materials are simultaneously dropped after 2-3 min. A. And the dripping time of the material B is controlled to be 2-3h, and the heat preservation is carried out for 1.5h after the dripping is finished. Then cooling and adding N with the mass concentration of 30 percent into the bottleand adjusting the pH value to be neutral by using the aOH solution to obtain the modified polycarboxylic acid water reducing agent for claystone concrete.
Example 2:
preparation of a third monomer intermediate: 160g of maleic anhydride is melted and then added into a reaction kettle, and then 3.2g of KOH and 2.9g of cocatalyst 18-crown ether-6 are added; sealing the kettle and replacing the kettle by high-purity nitrogen for three times; raising the temperature, keeping the temperature of the reaction kettle at 115-120 ℃, introducing 30g of epoxide, and controlling the pressure not to be higher than 0.1MPa to initiate a reaction primarily; when the reaction is initiated successfully, raising the reaction temperature to 135 ℃ at 125-; after curing, the mixture was degassed and neutralized with 6.5g of benzoic acid to obtain 795g of a third monomer intermediate having a molecular weight of 490.
Preparing a third monomer: adding 500g of the third monomer intermediate obtained in the step I into a reaction kettle, and adding 12.51g of methyl trioctyl ammonium chloride; sealing the kettle, replacing the kettle by high-purity nitrogen for more than three times, and dropwise adding 99g of epoxy chloropropane for carrying out ring-opening reaction for 4-5h at the temperature of 50-60 ℃; when the reaction is completed, 212.4g of tyrosine is added under the protection of nitrogen to maintain the temperature of 40-50 ℃ and react for 2-3h to obtain 801g of a third monomer with the molecular weight of 727.
Thirdly, synthesizing the modified polycarboxylic acid water reducing agent: 366.67g of 2200 g of methoxypolyethylene glycol methacrylate with molecular weight and 280g of deionized water are added into a four-neck flask, and stirred and dissolved for standby. Preparing a material A: 20g of acrylic acid and 80.8g of the third monomer were dissolved in 100g of deionized water. Preparing a material B: 0.37g of ascorbic acid (Vc) and 1.28g of mercaptopropionic acid were dissolved in 100g of deionized water. Into a four-necked flask was charged 11g of hydrogen peroxide (H)2O2) And A, B materials are simultaneously dropped after 2-3 min. A. And the dripping time of the material B is controlled to be 2-3h, and the heat preservation is carried out for 1.5h after the dripping is finished. And then cooling, and adding a NaOH solution with the mass concentration of 30% into the bottle to adjust the pH value to be neutral, thereby obtaining the modified polycarboxylic acid water reducing agent for claystone concrete.
Example 3:
preparation of a third monomer intermediate: adding 165g of maleic anhydride into a reaction kettle after melting, and then adding 1.98g of KOH and 2.1g of cocatalyst 18-crown ether-6; sealing the kettle and replacing the kettle by high-purity nitrogen for three times; raising the temperature, keeping the temperature of the reaction kettle at 115-120 ℃, introducing 22g of epoxide, and controlling the pressure not to be higher than 0.1MPa to initiate a reaction primarily; when the reaction initiation is successful, raising the reaction temperature to 135 ℃ at 125-; after curing, the mixture was degassed and neutralized with 3.46g of citric acid to obtain 655g of a 392 molecular weight third monomer intermediate.
Preparing a third monomer: adding 500g of the third monomer intermediate obtained in the step I into a reaction kettle, and adding 11.96g of triethyl ammonium chloride; sealing the kettle, replacing the kettle by high-purity nitrogen for more than three times, and dropwise adding 124g of epoxy chloropropane for carrying out ring-opening reaction for 4-5 hours at the temperature of 50-60 ℃; 299g of tryptophan is added under the protection of nitrogen when the reaction is completed, the temperature is maintained at 40-50 ℃, and the reaction is carried out for 2-3h, so that 913g of a third monomer with the molecular weight of 652 is obtained.
Thirdly, synthesizing the modified polycarboxylic acid water reducing agent: 322.92g of 1550 m-methoxy polyethylene glycol methacrylate and 260g of deionized water are added into a four-neck flask, and stirred and dissolved for later use. Preparing a material A: 25g of acrylic acid and 90.6g of the third monomer were dissolved in 100g of deionized water. Preparing a material B: 0.71g of ascorbic acid (Vc) and 0.65g of mercaptopropionic acid were added to 100g of deionized water to be dissolved. A four-necked flask was charged with 9.04g of hydrogen peroxide (H)2O2) And A, B materials are simultaneously dropped after 2-3 min. A. And the dripping time of the material B is controlled to be 2-3h, and the heat preservation is carried out for 1.5h after the dripping is finished. And then cooling, and adding a NaOH solution with the mass concentration of 30% into the bottle to adjust the pH value to be neutral, thereby obtaining the modified polycarboxylic acid water reducing agent for claystone concrete.
Example 4:
preparation of a third monomer intermediate: adding 170g of maleic anhydride into a reaction kettle after melting, and then adding 0.97g of KOH and 1.1g of cocatalyst 18-crown-6; sealing the kettle and replacing the kettle by high-purity nitrogen for three times; raising the temperature, keeping the temperature of the reaction kettle at 115-120 ℃, introducing 20g of epoxide, and controlling the pressure not to be higher than 0.1MPa to initiate a reaction primarily; after the reaction initiation is successful, raising the reaction temperature to 135 ℃ at 125-; after curing, the mixture was degassed and neutralized with 1.06g of glacial acetic acid to obtain 637g of a third monomer intermediate with molecular weight of 373.1.
Preparing a third monomer: adding 500g of the third monomer intermediate obtained in the step I into a reaction kettle, and adding 16.38g of tetrabutylammonium hydrogen sulfate; sealing the kettle, replacing the kettle by high-purity nitrogen for more than three times, and dropwise adding 130g of epoxy chloropropane at the temperature of 50-60 ℃ for ring-opening reaction for 4-5 hours; when the reaction is completed, under the protection of nitrogen, 279g of tyrosine is added to react for 2 to 3 hours at the temperature of 40 to 50 ℃ to obtain 889g of a third monomer with the molecular weight of 609.4.
Thirdly, synthesizing the modified polycarboxylic acid water reducing agent: 348.33g of 1900 g of methoxypolyethylene glycol acrylate with a molecular weight and 300g of deionized water are added into a four-neck flask, and stirred and dissolved for later use. Preparing a material A: 22g of acrylic acid and 74.5g of the third monomer were dissolved in 100g of deionized water. Preparing a material B: 0.63g of ascorbic acid (Vc) and 1.32g of mercaptopropionic acid were dissolved in 100g of deionized water. A four-necked flask was charged with 3.61g of hydrogen peroxide (H)2O2) And A, B materials are simultaneously dropped after 2-3 min. A. And the dripping time of the material B is controlled to be 2-3h, and the heat preservation is carried out for 1.5h after the dripping is finished. And then cooling, and adding a NaOH solution with the mass concentration of 30% into the bottle to adjust the pH value to be neutral, thereby obtaining the modified polycarboxylic acid water reducing agent for claystone concrete.
Example 5:
preparation of a third monomer intermediate: adding 165g of maleic anhydride into a reaction kettle after melting, and then adding 0.65g of KOH and 0.73g of cocatalyst 18-crown-6; sealing the kettle and replacing the kettle by high-purity nitrogen for three times; raising the temperature, keeping the temperature of the reaction kettle at 115-120 ℃, introducing 20g of epoxide, and controlling the pressure not to be higher than 0.1MPa to initiate a reaction primarily; after the reaction initiation is successful, raising the reaction temperature to 135 ℃ at 125-; after curing, the mixture was degassed and neutralized with 1.35g of benzoic acid to obtain 584g of a third monomer intermediate having a molecular weight of 352.8.
Preparing a third monomer: adding 500g of the third monomer intermediate obtained in the step I into a reaction kettle, and adding 8.73g of methyl trioctyl ammonium chloride; sealing the kettle, replacing the kettle by high-purity nitrogen for more than three times, and dropwise adding 138g of epoxy chloropropane for carrying out ring-opening reaction for 4-5h at the temperature of 50-60 ℃; when the reaction is completed, 332.48g of tryptophan is added under the protection of nitrogen to maintain the temperature of 40-50 ℃ and react for 2-3h to obtain 954g of a third monomer with the molecular weight of 612.8.
Thirdly, synthesizing the modified polycarboxylic acid water reducing agent: 420g of 2100 g of methoxypolyethylene glycol acrylate with a molecular weight and 200g of deionized water are added into a four-neck flask, and stirred and dissolved for later use. Preparing a material A: 24g of acrylic acid and 81.7g of the third monomer were dissolved in 100g of deionized water. Preparing a material B: 1.26g of ascorbic acid (Vc) and 0.92g of mercaptopropionic acid were added to 100g of deionized water to be dissolved. A four-necked flask was charged with 9.24g of hydrogen peroxide (H)2O2) And A, B materials are simultaneously dropped after 2-3 min. A. And the dripping time of the material B is controlled to be 2-3h, and the heat preservation is carried out for 1.5h after the dripping is finished. And then cooling, and adding a NaOH solution with the mass concentration of 30% into the bottle to adjust the pH value to be neutral, thereby obtaining the modified polycarboxylic acid water reducing agent for claystone concrete.
Claims (10)
1. A preparation method of a modified polycarboxylate superplasticizer for claystone concrete comprises the following steps:
preparation of a third monomer intermediate: adding melted maleic anhydride into a reaction kettle, and adding a proper amount of KOH and 18-crown-6 serving as a cocatalyst according to a certain ratio; sealing the kettle and replacing the kettle by high-purity nitrogen for more than three times; raising the temperature, keeping the temperature of the reaction kettle at 115-plus-120 ℃, introducing a small amount of epoxide, controlling the pressure to be not higher than 0.1MPa for primary initiation, after the reaction initiation is successful, raising the reaction temperature to 125-plus-135 ℃, controlling the reaction pressure to be not higher than 0.6MPa, finishing the rest epoxide, and curing for 1.5h after the feeding is finished; after curing, degassing and neutralizing to obtain a third monomer intermediate;
preparing a third monomer: adding the third monomer intermediate obtained in the step I into a reaction kettle, adding a phase transfer catalyst, sealing the kettle, replacing for more than three times by using high-purity nitrogen, dropwise adding epoxy chloropropane for carrying out ring opening reaction for 4-5h at the temperature of 50-60 ℃, adding amino acid for carrying out reaction for 2-3h at the temperature of 40-50 ℃ under the protection of nitrogen after the reaction is completed, and obtaining a third monomer;
thirdly, synthesizing the modified polycarboxylic acid water reducing agent: adding a polyether macromonomer and deionized water into a container, and stirring and dissolving for later use; preparing a material A: dissolving a certain amount of acrylic acid and a third monomer in deionized water; preparing a material B: dissolving a certain amount of ascorbic acid (Vc) and mercaptopropionic acid in deionized water; adding a certain amount of hydrogen peroxide into a container, dripping A, B materials after 2-3min, controlling the dripping time of A, B materials at 2-3h, keeping the temperature for 1.5h after finishing dripping, cooling, and adding NaOH solution with the mass concentration of 30% into the container to adjust the pH to be neutral, thus obtaining the product.
2. The method for preparing the modified polycarboxylate superplasticizer for claystone concrete according to claim 1, which is characterized by comprising the following steps: the using amount of KOH used in the step (i) is 0.05-0.50% of the total mass of reactants, and the molar ratio of KOH to the cocatalyst 18-crown-6 is 1: 0.2-0.3.
3. The method for preparing the modified polycarboxylate superplasticizer for claystone concrete according to claim 1, which is characterized by comprising the following steps: in the step I, the introduced epoxide is a mixture of ethylene oxide and propylene oxide, and the initiation amount of the epoxide is not more than 5% of the total feeding amount; wherein the mass ratio of the propylene oxide to the ethylene oxide is 1: 0.7-3.8.
4. The method for preparing the modified polycarboxylate superplasticizer for claystone concrete according to claim 1, which is characterized by comprising the following steps: in the step (i), the mass ratio of the maleic anhydride to the epoxide is 1: 2.6-4.1.
5. The method for preparing the modified polycarboxylate superplasticizer for claystone concrete according to claim 1, which is characterized by comprising the following steps: the amino acid used in the second step is one or more of histidine, tryptophan and tyrosine.
6. The method for preparing the modified polycarboxylate superplasticizer for claystone concrete according to claim 1, which is characterized by comprising the following steps: in the step II, the molar ratio of the third monomer intermediate to the epichlorohydrin to the amino acid is 1: 1.05: 1.15.
7. the method for preparing the modified polycarboxylate superplasticizer for claystone concrete according to claim 1, which is characterized by comprising the following steps: the phase transfer catalyst in the step (II) is one or more of triethyl ammonium chloride, tetrabutyl ammonium chloride, methyl trioctyl ammonium chloride and tetrabutyl ammonium hydrogen sulfate, and the dosage of the phase transfer catalyst is 0.5-2.0% of the total mass of reactants.
8. The method for preparing the modified polycarboxylate superplasticizer for claystone concrete according to claim 1, which is characterized by comprising the following steps: in the step (c), the polyether macromonomer is one or more of methoxy polyethylene glycol acrylate and methoxy polyethylene glycol methacrylate, and the molecular weight is 1500-.
9. The method for preparing the modified polycarboxylate superplasticizer for claystone concrete according to claim 1, which is characterized by comprising the following steps: in the third step, the dosage of the ascorbic acid is 0.1-0.3 percent of the mass of the polyether macromonomer, the dosage of the mercaptopropionic acid is 0.2-0.4 percent of the mass of the polyether macromonomer, and the dosage of the hydrogen peroxide is 1.0-3.0 percent of the mass of the polyether macromonomer.
10. The method for preparing the modified polycarboxylate superplasticizer for claystone concrete according to claim 1, which is characterized by comprising the following steps: in the step (c), the molar ratio of the acrylic acid to the third monomer to the polyether macromonomer is 2.5:1: 1.5.
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| CN113603840A (en) * | 2021-09-06 | 2021-11-05 | 抚顺东科精细化工有限公司 | Preparation method of antirust slow-release polycarboxylic acid superplasticizer |
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| CN104193215A (en) * | 2014-09-02 | 2014-12-10 | 武汉理工大学 | Ternary block macromonomer graft copolymerization high-property polycarboxylic acid water-reducing agent and preparation method thereof |
| US20150291716A1 (en) * | 2012-12-05 | 2015-10-15 | Sobute New Materials Co., Ltd. | Slump retaining polycarboxylic acid superplasticizer |
| CN110078910A (en) * | 2018-01-25 | 2019-08-02 | 北京砼帮汇科技有限公司 | A kind of poly carboxylic acid series water reducer branch polyether monomer and its synthetic method |
| CN110760037A (en) * | 2019-11-18 | 2020-02-07 | 中建材料技术研究成都有限公司 | Amino acid modified mud-resistant polycarboxylate superplasticizer and preparation method thereof |
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| US20150291716A1 (en) * | 2012-12-05 | 2015-10-15 | Sobute New Materials Co., Ltd. | Slump retaining polycarboxylic acid superplasticizer |
| CN104193215A (en) * | 2014-09-02 | 2014-12-10 | 武汉理工大学 | Ternary block macromonomer graft copolymerization high-property polycarboxylic acid water-reducing agent and preparation method thereof |
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| CN113603840B (en) * | 2021-09-06 | 2023-09-19 | 抚顺东科精细化工有限公司 | Preparation method of rust-proof slow-release polycarboxylic acid superplasticizer |
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