A modifying component and its use as a carbonation modifier for concrete
By introducing modified components into concrete as long-branched modifiers, the problems of singularity and high cost in improving the carbonation resistance of concrete are solved. This achieves the improvement of fluidity, strength and workability while reducing cement usage, and is also environmentally friendly.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- JIANGSU RES INST OF BUILDING SCI CO LTD
- Filing Date
- 2022-09-26
- Publication Date
- 2026-05-29
AI Technical Summary
Existing technologies offer limited options for improving concrete's resistance to carbonation, are costly, inconvenient to implement, and have limited lifespans for external protective coatings, failing to meet the requirements for ensuring concrete's resistance to carbonation under long-life conditions.
The use of modified components and their application as concrete carbonation modifiers has the advantages of saving cement, improving concrete workability and carbonation resistance, convenient preparation, no odor, environmental friendliness, and low cost. To avoid the negative impact of steric hindrance by incorporating long branches into the molecular structure of functional monomers, the modified components improve the workability of concrete, offering advantages such as convenient use, no odor, environmental friendliness, and low cost. Furthermore, to prevent the functional components from being affected, long branches are introduced into the molecular structure to ensure their effectiveness. Internal admixture addresses carbonation issues, offering advantages such as convenient use and low cost.
It achieves improved concrete fluidity, strength, and durability, optimized construction performance, reduced production costs, and environmental friendliness while reducing cement usage.
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Figure CN117800634B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of building materials technology, specifically to a modified component and its application as a concrete carbonation modifier. Background Technology
[0002] The rapid development of infrastructure has driven the year-on-year growth in the demand for concrete, and cement, as one of the most important components of concrete, has seen a corresponding increase in demand. On the one hand, with the nationwide large-scale power rationing in 2021, cement production was restricted, and cement prices continued to rise due to supply and demand dynamics. On the other hand, with increased environmental protection efforts, the quality of aggregates used in concrete has been declining year by year. To ensure strength, the amount of cement used per cubic meter of concrete has increased, directly leading to increased concrete production costs and an increased risk of carbonation in concrete structures. This results in reduced alkalinity of the concrete matrix, weakened durability, and in severe cases, directly jeopardizes the service safety of concrete structures.
[0003] Patent CN201810397023.9 discloses a hydrophobic strong impregnation protective structure for preventing concrete carbonation. The patent provides an impregnating agent coating that is applied to the surface of the concrete structure to form a hydrophobic protective structure layer to achieve the effect of resisting carbonation.
[0004] Patent 202110944086.3 discloses a concrete carbonation inhibitor and its preparation method, relating to the field of concrete surface protection technology. The carbonation inhibitor comprises a film-forming agent, a film-forming accelerator, a CO2 absorbent, a sealing agent, and a penetrant; wherein the film-forming agent is one or more of magnesium fluorosilicate, sodium fluorosilicate, and γ-(2,3-epoxypropoxy)propyltrimethoxysilane; the film-forming accelerator is one or more of lithium silicate, sodium silicate, and potassium silicate; the CO2 absorbent is one or more of potassium carbonate, sodium carbonate, triethanolamine, and 2,2-dihydroxydiethylamine; the sealing agent is modified silica sol; and the penetrant is one or more of hexadecyltrimethylammonium bromide, hexadecyl alcohol polyoxyethylene ether dimethyl octyl ammonium chloride, and octadecyl dimethyl benzyl ammonium chloride. This concrete carbonation inhibitor uses readily available raw materials and has a simple preparation process. It can both physically isolate CO2 and absorb CO2 diffused to the concrete surface, achieving dual protection against concrete carbonation.
[0005] The coatings involved in patents CN201810397023.9 and 202110944086.3 not only increase the construction and maintenance costs of concrete, but also have a limited service life under natural conditions, failing to meet the requirements for long service life and ensuring the anti-carbonation performance of concrete.
[0006] Patent 201811000732.5 discloses an early-strength polycarboxylate superplasticizer and its preparation method. This superplasticizer is prepared by free radical polymerization of unsaturated polyethers, unsaturated carboxylic acids, unsaturated esters containing alkanolamine groups, and unsaturated compounds containing amide groups in a redox system under the action of a chain transfer agent. The preparation process requires no heat source and is environmentally friendly. The resulting superplasticizer uses unsaturated polyethers with long side chains, which has a certain enhancing effect on the early strength of cement and concrete components. The unsaturated esters containing alkanolamine groups and the unsaturated compounds containing amide groups are selected as unsaturated early-strength monomers. The alkanolamine and amide groups promote C3A hydration, generating ettringite, accelerating the cement hydration acceleration period, shortening the cement setting time, thereby improving early strength and increasing the production efficiency of cement and concrete components. Simultaneously, the carboxylic acid and ester groups in the superplasticizer molecule give it good dispersibility and dispersion retention. By grafting early-strength functional groups into the structure of water-reducing agents, and because these early-strength functional groups occupy only a small portion of the water-reducing agent's molecular chain, their effectiveness in application is easily affected by the strong steric hindrance of the water-reducing agent. Summary of the Invention
[0007] To address the limitations of existing technologies that only improve concrete workability and strength, and enhance its carbonation resistance through external protective coatings, which suffer from high costs and inconvenient application, this invention provides a modified component and its application as a concrete carbonation modifier. This modified component, in application, saves cement, improves concrete workability and carbonation resistance, and is convenient to prepare, odorless, environmentally friendly, and low-cost. To avoid affecting the effectiveness of functional components, the functional components are designed as long branches in the molecular structure, avoiding the negative impact of steric hindrance and ensuring their effectiveness. Furthermore, the functional components dominate the main chain, effectively guaranteeing their strengthening and carbonation-inhibiting effects. With a molecular weight less than one percent of that of water-reducing agents, it can achieve rapid dispersion in cementitious materials, which is of great significance for improving the carbonation resistance of concrete and ensuring its service performance.
[0008] A modified component, which is obtained by the condensation reaction of an unsaturated alkanolamine and an unsaturated carboxylic acid I; the structure of the unsaturated alkanolamine is shown in formula (1) below:
[0009] Where m is an integer from 3 to 10, and n is an integer from 3 to 10; R1, R2 and R3 are independent of each other as H, CH3, CH2CH2OH or CH2CH(OH)CH3; the molar ratio of the above unsaturated alcohol amines and unsaturated carboxylic acids I is 1:(0.2 to 0.6).
[0010] The unsaturated carboxylic acid I mentioned above is at least one of acrylic acid, methacrylic acid, maleic anhydride, and fumaric acid.
[0011] The above condensation reaction process uses an initiator and a chain transfer agent. The initiator is at least one of azobisisobutyronitrile, ammonium persulfate, potassium persulfate, and ditert-butyl peroxide. The chain transfer agent is at least one of 3-mercaptopropionic acid, mercaptoacetic acid, dodecyl mercaptan, and isopropanol.
[0012] The condensation reaction temperature is 50℃~90℃, and the reaction time is 8h~14h. The post-condensation reaction treatment process requires the use of a pH adjuster to adjust the pH to 7~9. The pH adjuster is at least one of sodium hydroxide and potassium hydroxide.
[0013] The above-mentioned unsaturated alkanolamines are obtained by esterification of unsaturated carboxylic acids II and alkanolamine compounds.
[0014] The unsaturated carboxylic acid II mentioned above is at least one of 9-octadecenoic acid, 7-hexadecenoic acid, 4-eicosenoic acid, and 5-dodecenoic acid; the above-mentioned alkanolamine compound is at least one of diethanolamine, triethanolamine, diethanol monoisopropanolamine, triisopropanolamine, and N-methyldiethanolamine, wherein the molar ratio of unsaturated carboxylic acid II to alkanolamine compound is 1:(0.5 to 1.2).
[0015] A catalyst is used in the above esterification reaction process. The catalyst is any one of p-toluenesulfonic acid, tetrabutyl titanate, concentrated sulfuric acid, and concentrated hydrochloric acid. The esterification reaction temperature is 110℃~180℃ and the reaction time is 4h~8h.
[0016] A concrete carbonation modifier, comprising the following components mixed in percentage by mass:
[0017]
[0018] The above-mentioned defoaming component is at least one of tributyl phosphate, diisobutyl methanol, polydimethylsiloxane, and carboxylic acid-N-alkylamide; the above-mentioned setting-regulating component is at least one of glucose, sodium gluconate, sodium lignosulfonate, and sucrose; the above-mentioned thickening component is at least one of hydroxypropyl cellulose, carboxymethyl cellulose ether, methyl cellulose ether, and hydroxyethyl cellulose.
[0019] A method for preparing a concrete carbonation modifier involves metering the modifier, defoamer, retarder, thickener, and water according to a certain ratio, adding them to a reaction vessel, and mixing and stirring at room temperature for 30 minutes to obtain the concrete carbonation modifier.
[0020] The above-mentioned concrete carbonation modifier is applied to cement-based materials, and its dosage is 0.1% to 0.5% of the amount of cementitious material.
[0021] The present invention has the following advantages over the prior art:
[0022] 1. The concrete carbonation modifier of the present invention is prepared by condensation reaction of functional monomers and unsaturated carboxylic acids. The functional components introduced into the structure extend as long branches in the pore solution of the slurry, providing steric hindrance, improving the dispersion of cement particles, and improving the fluidity of concrete. In addition, the functional functional groups of the functional components extending in the pore liquid introduce functional groups of alcohol amine structure into the molecular structure, which can adsorb and neutralize CO2 entering the concrete through dissolution and transport in the environment, reduce the probability of neutralization of hydration product calcium hydroxide, ensure the alkalinity of the concrete system, and improve the carbonation resistance of concrete in high carbon dioxide environment. The carboxyl groups are adsorbed on the surface of cement particles, giving the cement particles electrical properties, so that the cement particles repel each other due to the same charge, improve the dispersion performance of cement particles, and provide a certain water-reducing effect.
[0023] 2. The concrete carbonation modifier of the present invention utilizes a condensation reaction to prepare organic molecules with special functional groups as a modifying component. After being incorporated into concrete, on the one hand, some of the branches undergo hydrolysis, and the hydrolyzed molecules with alkanolamine structures are dispersed in the pore solution, which accelerates the dissolution and hydration process of cement mineral components and improves the strength of concrete; on the other hand, the branches that have not undergone hydrolysis adsorb and neutralize CO2 dissolved in the pore solution, thereby inhibiting carbonation on the concrete surface and improving the durability of concrete.
[0024] 3. Defoaming components cause the air bubbles introduced during concrete production to gradually decompose into smaller air bubbles. These smaller air bubbles create a ball-bearing effect, improving the workability of the concrete and optimizing its internal pore structure. Retarding components adjust the setting time of the concrete, ensuring its workability. Thickening components, through their high molecular weight, provide and optimize the bonding performance between the paste and aggregate in the concrete, improving its pumpability.
[0025] 4. The concrete carbonation modifier of the present invention changes the traditional method of reducing concrete carbonation by requiring external protection, and solves the carbonation problem by internal admixture. It is convenient to use and low in cost. In addition, the concrete carbonation modifier of the present invention can also ensure the development of concrete strength while appropriately reducing the amount of cement, further optimizing the production cost of concrete production units. At the same time, the product is inexpensive, easy to use, and environmentally friendly. Attached Figure Description
[0026] Figure 1 The carbonation resistance of concrete prepared with the concrete carbonation modifier provided in Example 4;
[0027] Figure 2The carbonation resistance of concrete prepared with the concrete carbonation modifier provided in Comparative Example 1. Detailed Implementation
[0028] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.
[0029] Example 1
[0030] This embodiment discloses a concrete carbonation modifier and its preparation method, comprising the following components in parts by weight: 10% modifier, 0.05% defoamer, 3% retarder, 0.01% thickener, and water as the balance. The modifier is prepared by reacting functional monomers, acrylic acid, and methacrylic acid at 90°C for 10 hours under the action of azobisisobutyronitrile, ammonium persulfate, and 3-mercaptopropionic acid, followed by adding sodium hydroxide to adjust the pH to 9. The functional monomer is prepared by reacting 9-octadecenoic acid, diethanolamine, and triethanolamine at 120°C for 4 hours under the action of a catalyst. The molar ratio of the functional monomer to unsaturated carboxylic acid I is 1:0.2, the molar ratio of acrylic acid to methacrylic acid is 1:1, the mass ratio of azobisisobutyronitrile to ammonium persulfate is 1:1, the molar ratio of 9-octadecenoic acid to unsaturated carboxylic acid II is 1:0.5, and the molar ratio of diethanolamine to triethanolamine is 1:1. The defoaming component is tributyl phosphate and diisobutyl methanol in a 1:1 mass ratio, the retarding component is glucose and sodium gluconate in a 1:2 mass ratio, and the thickening component is hydroxypropyl cellulose. After measuring the above components according to the proportions, they are added into the reaction vessel and mixed and stirred at room temperature for 30 minutes to obtain the concrete carbonation modifier.
[0031] Example 2
[0032] This embodiment discloses a concrete carbonation modifier and its preparation method, comprising the following components in parts by weight: 3% modifier, 0.01% defoamer, 1% retarder, 0.1% thickener, and water as the balance. The modifier is prepared by reacting a functional monomer with unsaturated maleic anhydride and fumaric acid at 50°C for 8 hours under the action of potassium persulfate, dodecyl mercaptan, and isopropanol, followed by adjusting the pH to 7 with potassium hydroxide. The functional monomer is prepared by reacting 4-eicosenoic acid and diethanolmonoisopropanolamine at 110°C for 6 hours under the action of concentrated sulfuric acid. The molar ratio of the functional monomer to unsaturated carboxylic acid I is 1:0.6, the molar ratio of maleic anhydride to fumaric acid is 1:2, the mass ratio of dodecyl mercaptan to isopropanol is 2:1, and the molar ratio of 4-eicosenoic acid to diethanolmonoisopropanolamine is 1:1.2. The defoamer is tributyl phosphate and carboxylic acid-N-alkylamide in a mass ratio of 1:3. The retarding components are sodium gluconate and sodium lignosulfonate in a mass ratio of 2:1, and the thickening components are carboxymethyl cellulose ether and methyl cellulose ether. After measuring the above components according to the proportions, they are put into the reaction vessel and mixed and stirred at room temperature for 30 minutes to obtain the concrete carbonation modifier.
[0033] Example 3
[0034] This embodiment discloses a concrete carbonation modifier and its preparation method, comprising the following components in parts by weight: 5% modifier, 1% defoamer, 1.5% retarder, 0.06% thickener, and water as the balance. The modifier is prepared by reacting a functional monomer with methacrylic acid and maleic anhydride at 70°C for 10 hours under the action of potassium persulfate, mercaptoacetic acid, and isopropanol, followed by adding sodium hydroxide to adjust the pH to 8. The functional monomer is prepared by reacting 7-hexadecenoic acid with N-methyldiethanolamine and diethanolmonoisopropanolamine at 180°C for 6 hours under the action of p-toluenesulfonic acid. The molar ratio of the functional monomer to unsaturated carboxylic acid I is 1:0.4, the molar ratio of methacrylic acid to maleic anhydride is 3:2, the mass ratio of mercaptoacetic acid to isopropanol is 2:1:0.5, the molar ratio of 7-hexadecenoic acid to unsaturated carboxylic acid II is 1:0.8, and the molar ratio of N-methyldiethanolamine to diethanolmonoisopropanolamine is 1:2. The defoaming component is carboxylic acid-N-alkylamide, the retarding component is sucrose, and the thickening component is hydroxyethyl cellulose. After measuring the above components in proportion, they are added into the reaction vessel and mixed and stirred at room temperature for 30 minutes to obtain the concrete carbonation modifier.
[0035] Example 4
[0036] This embodiment discloses a concrete carbonation modifier and its preparation method, comprising the following components in parts by weight: 8% modifier, 0.8% defoamer, 2% retarder, 0.08% thickener, and water as the balance. The modifier is prepared by reacting functional monomers with methacrylic acid at 80°C for 14 hours under the action of potassium persulfate and mercaptoacetic acid, followed by adding sodium hydroxide to adjust the pH to 8. The functional monomers are prepared by reacting 7-hexadecenoic acid, 5-dodecenoic acid, N-methyldiethanolamine, and diethanolmonoisopropanolamine at 150°C for 7 hours under the action of p-toluenesulfonic acid. The molar ratio of functional monomers to methacrylic acid is 1:0.3, the molar ratio of unsaturated carboxylic acid II to alkanolamine is 1:1, the molar ratio of 7-hexadecenoic acid to 5-dodecenoic acid is 2:1, and the molar ratio of N-methyldiethanolamine to diethanolmonoisopropanolamine is 1:1. The defoaming component is carboxylic acid-N-alkylamide, the retarding component is sucrose and sodium gluconate in a mass ratio of 1:1, and the thickening component is hydroxyethyl cellulose and carboxymethyl cellulose ether in a mass ratio of 1:1. After measuring the above components according to the proportions, they are put into the reaction vessel and mixed and stirred at room temperature for 30 minutes to obtain the concrete carbonation modifier.
[0037] Example 5
[0038] This embodiment discloses a concrete carbonation modifier and its preparation method, comprising the following components in parts by weight: 6% modifier, 0.5% defoamer, 1% retarder, 0.08% thickener, and water as the balance. The modifier is prepared by reacting functional monomers with methacrylic acid and fumaric acid at 80°C for 12 hours under the action of potassium persulfate and mercaptoacetic acid, followed by adding sodium hydroxide to adjust the pH to 8. The functional monomers are prepared by reacting 9-octadecenoic acid, 5-dodecenoic acid, N-methyldiethanolamine, and diethanolmonoisopropanolamine at 160°C for 6 hours under the action of p-toluenesulfonic acid. The molar ratio of the functional monomers to unsaturated carboxylic acid I is 1:0.4, the molar ratio of methacrylic acid to fumaric acid is 1:2, the molar ratio of unsaturated carboxylic acid II to alkanolamine is 1:0.7, the molar ratio of 9-octadecenoic acid to 5-dodecenoic acid is 1:1, and the molar ratio of N-methyldiethanolamine to diethanolmonoisopropanolamine is 1:1. The defoaming components are tributyl phosphate and carboxylic acid-N-alkylamide in a mass ratio of 2:1, the retarding components are sucrose and glucose in a mass ratio of 2:1, and the thickening component is carboxymethyl cellulose ether. After measuring the above components according to the proportions, they are put into the reaction vessel and mixed and stirred at room temperature for 30 minutes to obtain the concrete carbonation modifier.
[0039] Example 6
[0040] This embodiment discloses a concrete carbonation modifier and its preparation method, comprising the following components in parts by weight: 15% modifier, 0.06% defoamer, 0.8% retarder, 0.08% thickener, and water as the balance. The modifier is prepared by reacting functional monomers with methacrylic acid and fumaric acid at 80°C for 13 hours under the action of potassium persulfate and thioglycolic acid, followed by adding sodium hydroxide to adjust the pH to 8. The functional monomers are prepared by reacting 9-octadecenoic acid, 5-dodecenoic acid, N-methyldiethanolamine, and diethanolmonoisopropanolamine at 160°C for 6 hours under the action of p-toluenesulfonic acid. The molar ratio of the functional monomer to unsaturated carboxylic acid I is 1:0.2, the molar ratio of methacrylic acid to fumaric acid is 1:1, the molar ratio of unsaturated carboxylic acid II to alkanolamine is 1:0.5, the molar ratio of 9-octadecenoic acid to 5-dodecenoic acid is 1:2, and the molar ratio of N-methyldiethanolamine to diethanolmonoisopropanolamine is 1:1. The defoaming components are tributyl phosphate and carboxylic acid-N-alkylamide in a mass ratio of 1:2, the retarding components are sucrose and glucose in a mass ratio of 1:3, and the thickening component is carboxymethyl cellulose ether. After measuring the above components according to the proportions, they are put into the reaction vessel and mixed and stirred at room temperature for 30 minutes to obtain the concrete carbonation modifier.
[0041] Comparative Example 1
[0042] This comparative example discloses a concrete carbonation modifier and its preparation method, comprising the following components in parts by weight: 5% modifier, 0.5% defoamer, 1% retarder, 0.08% thickener, and water as the balance; the modifier is a single component of triethanolamine. The defoamer consists of tributyl phosphate and carboxylic acid-N-alkylamide in a mass ratio of 1:2, the retarder consists of sucrose and glucose in a mass ratio of 1:1, and the thickener is carboxymethyl cellulose ether. After measuring the above components according to the proportions, they are added to a reaction vessel and mixed and stirred at room temperature for 30 minutes to obtain the concrete carbonation modifier.
[0043] Comparative Example 2
[0044] This embodiment discloses a concrete carbonation modifier and its preparation method, comprising the following components in parts by weight: 6% modifier, 0.5% defoamer, 1% retarder, 0.08% thickener, and water as the balance. The modifier is prepared by reacting 9-octadecenoic acid, 5-dodecenoic acid, N-methyldiethanolamine, and diethanolmonoisopropanolamine at 160°C for 6 hours under the action of p-toluenesulfonic acid. The molar ratio of unsaturated carboxylic acid II to alkanolamine is 1:0.7, the molar ratio of 9-octadecenoic acid to 5-dodecenoic acid is 1:1, and the molar ratio of N-methyldiethanolamine to diethanolmonoisopropanolamine is 1:1. The defoamer is tributyl phosphate and carboxylic acid-N-alkylamide in a mass ratio of 2:1, the retarder is sucrose and glucose in a mass ratio of 1:1, and the thickener is carboxymethyl cellulose ether. After measuring the above components according to the proportions, they are added to a reaction vessel and mixed and stirred at room temperature for 30 minutes to obtain the concrete carbonation modifier.
[0045] Comparative Example 3
[0046] This embodiment discloses a concrete carbonation modifier and its preparation method, comprising the following components in parts by weight: 6% modifier, 0.5% defoamer, 1% retarder, 0.08% thickener, and water as the balance. The modifier is prepared by reacting methacrylic acid and fumaric acid at 80°C for 12 hours under the action of potassium persulfate and mercaptoacetic acid, followed by adding sodium hydroxide to adjust the pH to 8, wherein the molar ratio of methacrylic acid to fumaric acid is 1:1. The defoamer is diisobutylmethanol and carboxylic acid-N-alkylamide in a mass ratio of 1:1, the retarder is sucrose, and the thickener is carboxymethyl cellulose ether. After measuring the above components according to the proportions, they are added to a reaction vessel and mixed and stirred at room temperature for 30 minutes to obtain the concrete carbonation modifier.
[0047] Application Example 1: Performance Testing
[0048] Workability, strength, and carbonation resistance of the C30 concrete prepared in Examples 1-6 and Comparative Examples 1-3 were tested. Workability was directly reflected by concrete slump and spread, strength was reflected by concrete 28-day compressive strength, and carbonation resistance was evaluated by 28-day concrete carbonation depth.
[0049] The concrete mix proportions are shown in Table 1.
[0050] Table 1
[0051]
[0052] The test results are shown in Table 2:
[0053] Table 2
[0054]
[0055] As can be seen from the results in Table 2, the concrete prepared with the concrete carbonation modifier provided in the examples can significantly improve the workability, strength, and carbonation resistance of permeable concrete. Specifically, the results of Comparative Example 1 show that the carbonation resistance effect of the modifier using only the amine component is 17.8 mm carbonation depth after 28 days, while the concrete carbonation modifier obtained through the examples of this invention has a carbonation depth of no more than 15.5 mm after 28 days. This indicates that the functional monomer, as a long-chain extension in the pore solution, provides steric hindrance, improves the dispersion of cement particles, and achieves improved concrete fluidity. The functional properties of the amine structure... The group can adsorb and neutralize CO2 that enters the concrete through dissolution and transport in the environment, inhibit the probability of neutralization of hydration product calcium hydroxide, ensure the alkalinity of the concrete system, and improve the carbonation resistance of the concrete in a high carbon dioxide environment. Example 5 and Comparative Example 2 show that although the introduction of more alkanolamine structures can improve the carbonation resistance, the lack of carboxylic acid groups reduces the dispersion performance and spread of cement particles. The data results of Example 5 and Comparative Example 3 show the importance of the long branched structure of the functional monomer and functional groups such as alkanolamines in the present application for resisting carbonation and improving fluidity.
[0056] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.
Claims
1. A modified component, characterized in that: The modified component is obtained by the condensation reaction of unsaturated alkanolamine and unsaturated carboxylic acid I; The structure of the unsaturated alcoholamine is shown in formula (1): (1)， Where m is an integer from 3 to 10, and n is an integer from 3 to 10; R1, R2, and R3 are mutually independent and are H, CH3, CH2CH2OH, or CH2CH(OH)CH3; The unsaturated carboxylic acid I is at least one of acrylic acid, methacrylic acid, maleic anhydride, and fumaric acid. The molar ratio of the unsaturated alcoholamine to the unsaturated carboxylic acid I is 1:(0.2~0.6); The modified component is obtained by condensation reaction of unsaturated alkanolamine and unsaturated carboxylic acid I at 50℃~90℃ for 8h~14h under the action of initiator and chain transfer agent, and then pH is adjusted to 7~9 by adding pH adjuster. The condensation reaction process uses an initiator and a chain transfer agent. The initiator is at least one of azobisisobutyronitrile, ammonium persulfate, potassium persulfate, and ditert-butyl peroxide. The chain transfer agent is at least one of 3-mercaptopropionic acid, mercaptoacetic acid, dodecyl mercaptan, and isopropanol.
2. The modified component according to claim 1, characterized in that: The unsaturated alkanolamine is obtained by esterification of unsaturated carboxylic acid II and an alkanolamine compound; the unsaturated carboxylic acid II is at least one of 9-octadecenoic acid, 7-hexadecenoic acid, 4-eicosenoic acid, and 5-dodecenoic acid; the alkanolamine compound is at least one of diethanolamine, triethanolamine, diethanol monoisopropanolamine, triisopropanolamine, and N-methyldiethanolamine, wherein the molar ratio of unsaturated carboxylic acid II to the alkanolamine compound is 1:(0.5~1.2).
3. The modified component according to claim 2, characterized in that: A catalyst is used in the esterification reaction, and the catalyst is any one of p-toluenesulfonic acid, tetrabutyl titanate, concentrated sulfuric acid, and concentrated hydrochloric acid; the esterification reaction temperature is 110℃~180℃, and the reaction time is 4h~8h.
4. The modified component according to claim 1, characterized in that: The pH adjuster is at least one of sodium hydroxide and potassium hydroxide.
5. A concrete carbonation modifier, characterized in that, Includes the following components mixed in percentage by mass: Modified components 3%~15%; Defoaming component: 0.01%~1%; 1%~3% of the coagulation regulator; Thickening component: 0.01%~0.1%; Water balance; The modified component is the modified component as described in claim 1.
6. A concrete carbonation modifier according to claim 5, characterized in that: The defoaming component is at least one of tributyl phosphate, diisobutyl methanol, polydimethylsiloxane, and carboxylic acid-N-alkylamide; the setting-regulating component is at least one of glucose, sodium gluconate, sodium lignosulfonate, and sucrose; and the thickening component is at least one of hydroxypropyl cellulose, carboxymethyl cellulose ether, methyl cellulose ether, and hydroxyethyl cellulose.
7. A method for preparing a concrete carbonation modifier according to any one of claims 5-6, characterized in that: After measuring the modified component, defoaming component, retarding component, thickening component, and water according to the specified proportions, add them to the reaction vessel and mix and stir at room temperature for 90 minutes to obtain the concrete carbonation modifier.
8. The application of the concrete carbonation modifier according to any one of claims 5-6, characterized in that: The concrete carbonation modifier is applied to cement-based materials, and its dosage is 0.1% to 0.5% of the amount of cementitious material.