Rust-resistant polycarboxylate superplasticizer and preparation method thereof
By preparing a rust-inhibiting polycarboxylate superplasticizer with a specific structure, the problems of large usage and unsatisfactory compounding effect of existing rust inhibitors have been solved, achieving good rust inhibition performance, water reduction performance and early strength improvement.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-01-16
- Publication Date
- 2026-04-10
AI Technical Summary
Existing rust inhibitors have problems such as large usage in concrete, affecting concrete setting time or dosage, and the combination effect of polycarboxylate superplasticizers and rust inhibitors is not ideal, making it difficult to effectively delay steel corrosion.
A rust-inhibiting polycarboxylate superplasticizer is prepared by using raw materials such as dicarboxylic acid, alkanolamine monomer, p-toluenesulfonic acid and hydroquinone in a specific ratio, through stirring and adding oxidizing and reducing agents. The pH value is adjusted to 5-6 to form a structure with long-chain alkyl and ester groups, thereby achieving a double-layer protection and slow-release effect on steel bars.
The prepared rust-inhibiting polycarboxylate superplasticizer has good rust-inhibiting and water-reducing properties, prolongs the working time of concrete, enhances its compatibility with other concrete admixtures, improves workability, and increases early strength.
Smart Images
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Abstract
Description
Technical Field
[0001] This invention relates to the field of concrete admixtures, specifically to a rust-inhibiting polycarboxylate superplasticizer and its preparation method. Background Technology
[0002] In concrete engineering, the design philosophy prioritizing durability has been widely accepted by engineering designers. Extending the service life of concrete has become a hot topic in concrete research. Structural damage caused by poor concrete durability far outweighs damage caused by insufficient load-bearing capacity. Among structural damage caused by poor durability, steel corrosion accounts for a significant proportion and is one of the most common forms of concrete failure. Therefore, developing effective concrete corrosion inhibitors to prevent steel corrosion has always been a key research focus both domestically and internationally.
[0003] Common types of rust inhibitors include tungstates, molybdates, nitrites, phosphates, and alkanolamines. However, these rust inhibitors also have significant drawbacks. For example, nitrite rust inhibitors have strong toxic side effects and require large dosages; phosphate rust inhibitors affect the setting time of ready-mixed concrete; and alkanolamine rust inhibitors affect the dosage of ready-mixed concrete. Furthermore, in construction engineering, polycarboxylate superplasticizers and rust inhibitors are often compounded to obtain rust-inhibiting composite superplasticizers, but the properties of the two often interfere with each other, resulting in a less than ideal combined effect. Summary of the Invention
[0004] To address the aforementioned shortcomings of existing technologies, the present invention aims to provide a rust-inhibiting polycarboxylate superplasticizer and its preparation method, thereby delaying the corrosion of reinforced concrete steel bars and reducing the amount of rust inhibitor used.
[0005] The technical solution of this invention to solve the above-mentioned technical problems is as follows: A method for preparing a rust-inhibiting polycarboxylate superplasticizer is provided, comprising the following steps: S1: Mix dicarboxylic acid, alkanolamine monomer, p-toluenesulfonic acid and hydroquinone, stir at 60~80℃ for 3~5h, then add 0.2~0.5 parts of acrylic acid and stir for 2~3h to obtain the rust-inhibiting functional monomer; S2: Prepare a base material by mixing 330-400 parts of polyether macromonomer, 1-2 parts of oxidant and 300-350 parts of water; or prepare a base material by mixing 330-400 parts of polyether monomer, 300-350 parts of water and 5-30 parts of rust-inhibiting functional monomer and then adding 1-2 parts of oxidant. S3: Mix 10-30 parts of unsaturated functional monomer, 5-30 parts of rust-inhibiting functional monomer, 0.5-2 parts of chain transfer agent and 50 parts of water to prepare solution A; or mix 10-30 parts of unsaturated functional monomer, 0.5-2 parts of chain transfer agent and 50 parts of water to prepare solution A. S4: Mix 0.1~1 parts of reducing agent with water to prepare solution B; S5: Add solution A and solution B to the substrate obtained in step S2, and then adjust the pH to 5-6 with liquid alkali to obtain the final product.
[0006] Furthermore, the mass ratio of dicarboxylic acid, alcohol amine monomer, p-toluenesulfonic acid, and hydroquinone is 1:0.5~1.5:0.01:0.005.
[0007] Furthermore, the structure of the dicarboxylic acid is shown in Formula I: (I); Where Z is 10~15.
[0008] Furthermore, the alcohol amine monomer is at least one of ethanolamine and diethanolamine.
[0009] Furthermore, the molecular weight of the polyether macromonomer is 1000~4000; the polyether macromonomer is at least one of 4-hydroxybutylvinyl polyoxyethylene ether, ethylene glycol monovinyl polyethylene glycol ether, isopentenyl polyoxyethylene ether and methyl allyl polyoxyethylene ether.
[0010] Furthermore, the unsaturated functional monomer is at least one of acrylic acid, sodium acrylate, sodium acrylate sulfonate, sodium methacrylate sulfonate, itaconic acid, maleic anhydride, acrylamide, hydroxyethyl acrylate, and hydroxypropyl acrylate.
[0011] Furthermore, the oxidant is at least one of hydrogen peroxide, ammonium persulfate, sodium persulfate, and potassium persulfate; the reducing agent is at least one of ascorbic acid, sodium formaldehyde sulfoxylate, and sodium bisulfite.
[0012] Furthermore, the chain transfer agent is at least one of mercaptoethanol, mercaptoacetic acid, and mercaptopropionic acid.
[0013] The present invention also provides a rust-inhibiting polycarboxylate superplasticizer prepared by the above preparation method, the structure of which is shown in Formula II: (II); Wherein, A is an unsaturated functional small monomer structure, B is a rust-inhibiting functional monomer structure, and C is a polyether macromonomer structure; a is an integer from 0 to 20, b is an integer from 0 to 20, c is an integer from 0 to 10, and m is an integer from 1 to 10.
[0014] The present invention provides the following beneficial effects: A method for preparing a rust-inhibiting polycarboxylate superplasticizer is provided, resulting in a rust-inhibiting polycarboxylate superplasticizer with both excellent rust-inhibiting and water-reducing properties. The long-chain alkyl groups and alkanolamines in the structure of this rust-inhibiting polycarboxylate superplasticizer provide a double-layer protection, effectively preventing chloride ion penetration and damage to the passivation film on the steel reinforcement surface. Simultaneously, the hydrolysis of the ester groups and amides also plays a slow-release role, extending the concrete's working time, enhancing its compatibility with other concrete admixtures, improving the workability of the concrete, and increasing its early strength. Therefore, the rust-inhibiting polycarboxylate superplasticizer of the present invention possesses excellent rust-inhibiting, water-reducing, and early-strength properties. Attached Figure Description
[0015] Figure 1 This is a schematic diagram of the preparation process of the rust-inhibiting monomer in a rust-inhibiting polycarboxylate superplasticizer. Detailed Implementation
[0016] The examples given below are for illustrative purposes only and are not intended to limit the scope of the invention. Unless otherwise specified, conditions in the examples are performed under standard conditions or as recommended by the manufacturer. Reagents or instruments whose manufacturers are not specified are all commercially available products.
[0017] Example 1: A rust-inhibiting polycarboxylate superplasticizer, the preparation method of which includes the following steps: S1: Mix 10 parts sebacic acid, 10 parts diethanolamine, 0.1 parts p-toluenesulfonic acid, and 0.05 parts hydroquinone, stir at 60°C for 5 hours, then slowly add 5 parts acrylic acid, and continue heating and stirring for 2 hours to obtain the rust-inhibiting functional monomer (preparation process see...). Figure 1 ); S2: Under stirring conditions, 360 parts of 4-hydroxybutylvinyl polyoxyethylene ether (molecular weight 3000), 1.5 parts of hydrogen peroxide and 310 parts of water are mixed to prepare the base material. S3: Mix 24 parts acrylic acid, 15 parts rust-inhibiting functional monomer, 1.2 parts mercaptoethanol and 50 parts water to prepare solution A; S4: Mix 0.6 parts ascorbic acid and 50 parts water to prepare solution B; S5: Under stirring conditions, add solution A and solution B dropwise to the base material obtained in step S2. Solution A is added dropwise over a time of 40 minutes, and solution B is added dropwise over a time of 50 minutes. S6: After the addition is complete, keep warm for 30 minutes, then use liquid alkali and deionized water, stir and adjust the pH to 6 and the concentration to 40% to obtain the product.
[0018] Example 2: S1: Mix 10 parts sebacic acid, 10 parts ethanolamine, 0.1 parts p-toluenesulfonic acid and 0.05 parts hydroquinone, stir at 60°C for 5 hours, then slowly add 5 parts acrylic acid, and continue heating and stirring for 2 hours to obtain the rust-inhibiting functional monomer. S2: Under stirring conditions, 360 parts of 4-hydroxybutylvinyl polyoxyethylene ether (molecular weight 3000), 310 parts of water and 15 parts of rust-inhibiting functional monomer are mixed evenly, and 2.0 parts of ammonium persulfate are added to prepare the base material; S3: Mix 24 parts sodium methacrylate, 1.2 parts mercaptoacetic acid and 50 parts water to obtain solution A; S4: Mix 0.8 parts sodium bisulfite with 50 parts water to obtain solution B; S5: Under stirring conditions, add solution A and solution B dropwise to the base material obtained in step S2. Solution A is added dropwise over a time of 40 minutes, and solution B is added dropwise over a time of 50 minutes. S6: After the addition is complete, keep warm for 30 minutes, then use liquid alkali and deionized water, stir and adjust the pH to 6 and the concentration to 40% to obtain the product.
[0019] Example 3: S1: Mix 10 parts sebacic acid, 10 parts ethanolamine, 0.1 parts p-toluenesulfonic acid and 0.05 parts hydroquinone, stir at 60°C for 5 hours, then slowly add 5 parts acrylic acid, and continue heating and stirring for 2 hours to obtain the rust-inhibiting functional monomer. S2: Under stirring conditions, 360 parts of isopentenyl alcohol polyoxyethylene ether (molecular weight 2400), 310 parts of water and 15 parts of rust-inhibiting functional monomer are mixed evenly, and 1.5 parts of sodium persulfate are added to prepare the base material. S3: Mix 24 parts itaconic acid, 1.2 parts mercaptopropionic acid and 50 parts water to prepare solution A; S4: Mix 0.7 parts ascorbic acid and 50 parts water to prepare solution B; S5: Under stirring conditions, add solution A and solution B dropwise to the base material obtained in step S2. Solution A is added dropwise over a time of 120 min, and solution B is added dropwise over a time of 150 min. S6: After the addition is complete, keep warm for 30 minutes, then use liquid alkali and deionized water, stir and adjust the pH to 6 and the concentration to 40% to obtain the product.
[0020] Example 4: S1: Mix 10 parts sebacic acid, 10 parts ethanolamine, 0.1 parts p-toluenesulfonic acid and 0.05 parts hydroquinone, stir at 60°C for 5 hours, then slowly add 5 parts acrylic acid, and continue heating and stirring for 2 hours to obtain the rust-inhibiting functional monomer. S2: Under stirring conditions, 360 parts of 4-hydroxybutylvinyl polyoxyethylene ether (molecular weight 1000), 1.0 part of potassium persulfate and 310 parts of water are mixed to prepare the base material; S3: Mix 20 parts maleic anhydride, 15 parts rust-inhibiting functional monomer, 1.5 parts mercaptoethanol and 50 parts water to prepare solution A; S4: Mix 0.8 parts of sodium formaldehyde sulfoxylate and 50 parts of water to prepare solution B; S5: Under stirring conditions, add solution A and solution B dropwise to the base material obtained in step S2. Solution A is added dropwise over a time of 40 minutes, and solution B is added dropwise over a time of 50 minutes. S6: After the addition is complete, keep warm for 30 minutes, then use liquid alkali and deionized water, stir and adjust the pH to 6 and the concentration to 40% to obtain the product.
[0021] Example 5: S1: Mix 10 parts sebacic acid, 10 parts ethanolamine, 0.1 parts p-toluenesulfonic acid and 0.05 parts hydroquinone, stir at 60°C for 5 hours, then slowly add 5 parts acrylic acid, and continue heating and stirring for 2 hours to obtain the rust-inhibiting functional monomer. S2: Under stirring conditions, 360 parts of 4-hydroxybutylvinyl polyoxyethylene ether (molecular weight 4000), 2.0 parts of hydrogen peroxide and 310 parts of water are mixed to prepare the base material. S3: Mix 28 parts of hydroxyethyl acrylate, 15 parts of rust-inhibiting functional monomer, 1.2 parts of mercaptoethanol and 50 parts of water to prepare solution A; S4: Mix 0.6 parts ascorbic acid and 50 parts water to prepare solution B; S5: Under stirring conditions, add solution A and solution B dropwise to the base material obtained in step S2. Solution A is added dropwise over a time of 40 minutes, and solution B is added dropwise over a time of 50 minutes. S6: After the addition is complete, keep warm for 30 minutes, then use liquid alkali and deionized water, stir and adjust the pH to 6 and the concentration to 40% to obtain the product.
[0022] Example 6: S1: Mix 10 parts pentadecanoic acid, 10 parts ethanolamine, 0.1 parts p-toluenesulfonic acid and 0.05 parts hydroquinone, stir at 60°C for 5 hours, then slowly add 5 parts acrylic acid, and continue heating and stirring for 2 hours to obtain the rust-inhibiting functional monomer. S2: Under stirring conditions, 360 parts of 4-hydroxybutylvinyl polyoxyethylene ether (molecular weight 3000), 1.5 parts of hydrogen peroxide and 310 parts of water are mixed to prepare the base material. S3: Mix 24 parts acrylamide, 15 parts rust-inhibiting functional monomer, 1.2 parts mercaptoethanol and 50 parts water to prepare solution A; S4: Mix 0.6 parts ascorbic acid and 50 parts water to prepare solution B; S5: Under stirring conditions, add solution A and solution B dropwise to the base material obtained in step S2. Solution A is added dropwise over a time of 40 minutes, and solution B is added dropwise over a time of 50 minutes. S6: After the addition is complete, keep warm for 30 minutes, then use liquid alkali and deionized water, stir and adjust the pH to 6 and the concentration to 40% to obtain the product.
[0023] Example 7: S1: Mix 10 parts sebacic acid, 10 parts diethanolamine, 0.1 parts p-toluenesulfonic acid and 0.05 parts hydroquinone, stir at 60°C for 5 hours, then slowly add 5 parts acrylic acid, and continue heating and stirring for 2 hours to obtain the rust-inhibiting functional monomer. S2: Under stirring conditions, 360 parts of 4-hydroxybutylvinyl polyoxyethylene ether (molecular weight 3000), 1.5 parts of hydrogen peroxide and 310 parts of water are mixed to prepare the base material. S3: Mix 24 parts sodium propylene sulfonate, 15 parts rust-inhibiting functional monomer, 1.2 parts mercaptoethanol and 50 parts water to prepare solution A; S4: Mix 0.6 parts ascorbic acid and 50 parts water to prepare solution B; S5: Under stirring conditions, add solution A and solution B dropwise to the base material obtained in step S2. Solution A is added dropwise over a time of 40 minutes, and solution B is added dropwise over a time of 50 minutes. S6: After the addition is complete, keep warm for 30 minutes, then use liquid alkali and deionized water, stir and adjust the pH to 6 and the concentration to 40% to obtain the product.
[0024] Example 8: S1: Mix 10 parts sebacic acid, 10 parts ethanolamine, 0.1 parts p-toluenesulfonic acid and 0.05 parts hydroquinone, stir at 80°C for 3 hours, then slowly add 5 parts acrylic acid, and continue heating and stirring for 1 hour to obtain the rust-inhibiting functional monomer. S2: Under stirring conditions, 360 parts of 4-hydroxybutylvinyl polyoxyethylene ether (molecular weight 3000), 1.5 parts of hydrogen peroxide and 310 parts of water are mixed to prepare the base material. S3: Mix 24 parts sodium acrylate, 15 parts rust-inhibiting functional monomer, 1.2 parts mercaptoethanol and 50 parts water to prepare solution A; S4: Mix 0.6 parts ascorbic acid and 50 parts water to prepare solution B; S5: Under stirring conditions, add solution A and solution B dropwise to the base material obtained in step S2. Solution A is added dropwise over a time of 40 minutes, and solution B is added dropwise over a time of 50 minutes. S6: After the addition is complete, keep warm for 30 minutes, then use liquid alkali and deionized water, stir and adjust the pH to 6 and the concentration to 40% to obtain the product.
[0025] Example 9: S1: Mix 10 parts sebacic acid, 10 parts ethanolamine, 0.1 parts p-toluenesulfonic acid and 0.05 parts hydroquinone, stir at 60°C for 5 hours, then slowly add 5 parts acrylic acid, and continue heating and stirring for 2 hours to obtain the rust-inhibiting functional monomer. S2: Under stirring conditions, 360 parts of 4-hydroxybutylvinyl polyoxyethylene ether (molecular weight 3000), 1.5 parts of hydrogen peroxide and 310 parts of water are mixed to prepare the base material. S3: Mix 20 parts hydroxypropyl acrylate, 25 parts rust-inhibiting functional monomer, 1.2 parts mercaptoethanol and 50 parts water to prepare solution A; S4: Mix 0.6 parts ascorbic acid and 50 parts water to prepare solution B; S5: Under stirring conditions, add solution A and solution B dropwise to the base material obtained in step S2. Solution A is added dropwise over a time of 40 minutes, and solution B is added dropwise over a time of 50 minutes. S6: After the addition is complete, keep warm for 30 minutes, then use liquid alkali and deionized water, stir and adjust the pH to 6 and the concentration to 40% to obtain the product.
[0026] Example 10: S1: Mix 10 parts sebacic acid, 10 parts ethanolamine, 0.1 parts p-toluenesulfonic acid and 0.05 parts hydroquinone, stir at 60°C for 5 hours, then slowly add 5 parts acrylic acid, and continue heating and stirring for 2 hours to obtain the rust-inhibiting functional monomer. S2: Under stirring conditions, 360 parts of 4-hydroxybutylvinyl polyoxyethylene ether (molecular weight 3000), 1.5 parts of hydrogen peroxide and 310 parts of water are mixed to prepare the base material. S3: Mix 10 parts acrylic acid, 10 parts hydroxypropyl acrylate, 15 parts rust-inhibiting functional monomer, 1.2 parts mercaptoethanol and 50 parts water to prepare solution A; S4: Mix 0.6 parts ascorbic acid and 50 parts water to prepare solution B; S5: Under stirring conditions, add solution A and solution B dropwise to the base material obtained in step S2. Solution A is added dropwise over a time of 40 minutes, and solution B is added dropwise over a time of 50 minutes. S6: After the addition is complete, keep warm for 30 minutes, then use liquid alkali and deionized water, stir and adjust the pH to 6 and the concentration to 40% to obtain the product.
[0027] Comparative Example 1: S1: Under stirring conditions, 360 parts of 4-hydroxybutylvinyl polyoxyethylene ether (molecular weight 3000), 1.5 parts of hydrogen peroxide and 310 parts of water are mixed to prepare the base material. S2: Mix 24 parts acrylic acid, 1.2 parts mercaptoethanol and 50 parts water to prepare solution A; S3: Mix 0.6 parts ascorbic acid and 50 parts water to prepare solution B; S4: Under stirring conditions, add solution A and solution B dropwise to the base material obtained in step S1. Solution A is added dropwise over a time of 40 minutes, and solution B is added dropwise over a time of 50 minutes. S5: After the addition is complete, keep warm for 30 minutes, then use liquid alkali and deionized water, stir and adjust the pH to 6 and the concentration to 40% to obtain the product.
[0028] Comparative Example 2: S1: Mix 10 parts oxalic acid, 10 parts ethanolamine, 0.1 parts p-toluenesulfonic acid and 0.05 parts hydroquinone, stir at 60°C for 5 hours, then slowly add 5 parts acrylic acid, and continue heating and stirring for 2 hours to obtain the rust-inhibiting functional monomer. S2: Under stirring conditions, 360 parts of 4-hydroxybutylvinyl polyoxyethylene ether (molecular weight 3000), 1.5 parts of hydrogen peroxide and 310 parts of water are mixed to obtain the base material; 24 parts of acrylic acid, 15 parts of rust-inhibiting functional monomer, 1.2 parts of mercaptoethanol and 50 parts of water are mixed to obtain solution A. S3: Mix 0.6 parts ascorbic acid with 50 parts water to obtain solution B; S4: Under stirring conditions, add solution A and solution B dropwise to the base material obtained in step S2. Solution A is added dropwise for 40 minutes, and solution B is added dropwise for 50 minutes. S5: After the addition is complete, keep warm for 30 minutes, then use liquid alkali and deionized water, stir and adjust the pH to 6 and the concentration to 40% to obtain the rust-inhibiting polycarboxylate superplasticizer.
[0029] Comparative Example 3: S1: Mix 10 parts sebacic acid, 10 parts ethanolamine, 0.1 parts p-toluenesulfonic acid and 0.05 parts hydroquinone, stir at 30°C for 2 hours, then slowly add 5 parts acrylic acid, and continue heating and stirring for 1 hour to obtain the rust-inhibiting functional monomer. S2: Under stirring conditions, 360 parts of 4-hydroxybutylvinyl polyoxyethylene ether (molecular weight 3000), 1.5 parts of hydrogen peroxide and 310 parts of water are mixed to prepare the base material. S3: Mix 24 parts acrylic acid, 15 parts rust-inhibiting functional monomer, 1.2 parts mercaptoethanol and 50 parts water to prepare solution A; S4: Mix 0.6 parts ascorbic acid and 50 parts water to prepare solution B; S5: Under stirring conditions, add solution A and solution B dropwise to the base material obtained in step S2. Solution A is added dropwise over a time of 40 minutes, and solution B is added dropwise over a time of 50 minutes. S6: After the addition is complete, keep warm for 30 minutes, then use liquid alkali and deionized water, stir and adjust the pH to 6 and the concentration to 40% to obtain the product.
[0030] Comparative Example 4: S1: Mix 10 parts sebacic acid, 10 parts ethanolamine, 0.1 parts p-toluenesulfonic acid and 0 parts hydroquinone, stir at 60°C for 5 hours, then slowly add 5 parts acrylic acid, and continue heating and stirring for 2 hours to obtain the rust-inhibiting functional monomer. S2: Under stirring conditions, 360 parts of 4-hydroxybutylvinyl polyoxyethylene ether (molecular weight 3000), 1.5 parts of hydrogen peroxide and 310 parts of water are mixed to prepare the base material. S3: Mix 24 parts acrylic acid, 15 parts rust-inhibiting functional monomer, 1.2 parts mercaptoethanol and 50 parts water to prepare solution A; S4: Mix 0.6 parts ascorbic acid and 50 parts water to prepare solution B; S5: Under stirring conditions, add solution A and solution B dropwise to the base material obtained in step S2. Solution A is added dropwise over a time of 40 minutes, and solution B is added dropwise over a time of 50 minutes. S6: After the addition is complete, keep warm for 30 minutes, then use liquid alkali and deionized water, stir and adjust the pH to 6 and the concentration to 40% to obtain the product.
[0031] Comparative Example 5: S1: Mix 10 parts sebacic acid, 10 parts ethanolamine, 0.1 parts p-toluenesulfonic acid and 0.05 parts hydroquinone, stir at 60°C for 5 hours, then slowly add 0 parts acrylic acid, and continue heating and stirring for 2 hours to obtain the rust-inhibiting monomer. S2: Under stirring conditions, 360 parts of 4-hydroxybutylvinyl polyoxyethylene ether (molecular weight 3000), 1.5 parts of hydrogen peroxide and 310 parts of water are mixed to prepare the base material. S3: Mix 24 parts acrylic acid, 15 parts rust-inhibiting functional monomer, 1.2 parts mercaptoethanol and 50 parts water to prepare solution A; S4: Mix 0.6 parts ascorbic acid and 50 parts water to prepare solution B; S5: Under stirring conditions, add solution A and solution B dropwise to the base material obtained in step S2. Solution A is added dropwise over a time of 40 minutes, and solution B is added dropwise over a time of 50 minutes. S6: After the addition is complete, keep warm for 30 minutes, then use liquid alkali and deionized water, stir and adjust the pH to 6 and the concentration to 40% to obtain the product.
[0032] Experimental Example 1: Examples 1-9 of this application, Comparative Examples 1-5, commercially available polycarboxylate superplasticizer samples, and ethanolamine were compared to test the spread and changes over time of cement mortar. The spread and changes over time of the cement mortar, as well as the 1-day strength of the mortar, were compared at room temperature. The cement used was the reference cement (300g), the manufactured sand was standard sand (1350g), and water was 140g. All samples were diluted to 10%, with a total admixture of 2.0wt%. The spread loss rate was (0h spread - 1h spread) / 0h spread * 100%. The test results are shown in Table 1.
[0033] Table 1. Cement mortar fluidity and early strength As shown in Table 1, by comparing the water-reducing agents in Examples 1-9 and Comparative Examples 1-5, it can be seen that the rust-inhibiting polycarboxylate water-reducing agent prepared by the method of the present invention has a larger initial expansion degree and a lower expansion loss rate (expansion loss rate of 4-15% in the examples and 16-17% in the comparative examples). At the same time, the 1-day compressive strength is also relatively higher (1-day strength of 6.1-7.2 mPa in the examples and 4.7-6.0 mPa in the comparative examples). This indicates that the rust-inhibiting polycarboxylate water-reducing agent prepared by the method of the present invention has good water-reducing and flow retention properties, and also promotes the early strength development of cement mortar.
[0034] Experimental Example 2: Examples 1-9 of this application, comparative examples 1-5, commercially available polycarboxylate superplasticizer samples, and ethanolamine were compared. Referring to GB / T 31296-2014 "Concrete Corrosion Inhibitors," all samples were diluted to 10%, with a total dosage of 2.0 wt%, and their rust-inhibiting performance was tested. The test results are shown in Table 2.
[0035] Table 2 Rust Inhibition Performance As shown in Table 2, by comparing the electrical flux in Examples 1-9 and Comparative Examples 1-5, the rust-inhibiting polycarboxylate superplasticizer prepared by the method of the present invention has better resistance to chloride ion penetration (electric flux of the examples is 368-476, and that of the comparative examples and commercially available samples is 642-718). At the same time, the resistance to sulfate attack is also slightly improved, indicating that the rust-inhibiting polycarboxylate superplasticizer prepared by the method of the present invention has better rust-inhibiting performance in concrete.
[0036] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.
Claims
1. A method for preparing a rust-inhibiting polycarboxylate superplasticizer, characterized in that, Includes the following steps: S1: Mix dicarboxylic acid, alkanolamine monomer, p-toluenesulfonic acid and hydroquinone, stir at 60~80℃ for 3~5h, then add 0.2~0.5 parts of acrylic acid and stir for 2~3h to obtain the rust-inhibiting functional monomer; S2: Prepare a base material by mixing 330-400 parts of polyether macromonomer, 1-2 parts of oxidant and 300-350 parts of water; or prepare a base material by mixing 330-400 parts of polyether monomer, 300-350 parts of water and 5-30 parts of rust-inhibiting functional monomer and then adding 1-2 parts of oxidant. S3: Mix 10-30 parts of unsaturated functional monomer, 5-30 parts of rust-inhibiting functional monomer, 0.5-2 parts of chain transfer agent and 50 parts of water to prepare solution A; or mix 10-30 parts of unsaturated functional monomer, 0.5-2 parts of chain transfer agent and 50 parts of water to prepare solution A. S4: Mix 0.1~1 parts of reducing agent with water to prepare solution B; S5: Add solution A and solution B to the substrate obtained in step S2, and then adjust the pH to 5-6 with liquid alkali to obtain the final product.
2. The preparation method according to claim 1, characterized in that, The mass ratio of the dicarboxylic acid, alcohol amine monomer, p-toluenesulfonic acid, and hydroquinone is 1:0.5~1.5:0.01:0.
005.
3. The preparation method according to claim 1, characterized in that, The structure of the dicarboxylic acid is shown in Formula I: （I）； Where Z is 10~15.
4. The preparation method according to claim 1, characterized in that, The alcohol amine monomer is at least one of ethanolamine and diethanolamine.
5. The preparation method according to claim 1, characterized in that, The molecular weight of the polyether macromonomer is 1000~4000; the polyether macromonomer is at least one of 4-hydroxybutylvinyl polyoxyethylene ether, ethylene glycol monovinyl polyethylene glycol ether, isopentenyl polyoxyethylene ether and methyl allyl polyoxyethylene ether.
6. The preparation method according to claim 1, characterized in that, The unsaturated functional monomer is at least one of acrylic acid, sodium acrylate, sodium propylene sulfonate, sodium methpropylene sulfonate, itaconic acid, maleic anhydride, acrylamide, hydroxyethyl acrylate, and hydroxypropyl acrylate.
7. The preparation method according to claim 1, characterized in that, The oxidizing agent is at least one of hydrogen peroxide, ammonium persulfate, sodium persulfate, and potassium persulfate; the reducing agent is at least one of ascorbic acid, sodium formaldehyde sulfoxylate, and sodium bisulfite.
8. The preparation method according to claim 1, characterized in that, The chain transfer agent is at least one of mercaptoethanol, mercaptoacetic acid, and mercaptopropionic acid.
9. A rust-inhibiting polycarboxylate superplasticizer prepared by the preparation method according to any one of claims 1 to 8, characterized in that, The structure of the rust-inhibiting polycarboxylate superplasticizer is shown in Formula II: （Ⅱ）； Wherein, A is an unsaturated functional small monomer structure, B is a rust-inhibiting functional monomer structure, and C is a polyether macromonomer structure; a is an integer from 0 to 20, b is an integer from 0 to 20, c is an integer from 0 to 10, and m is an integer from 1 to 10.