Dispersing agent for concrete accelerator, preparation method of dispersing agent and concrete accelerator

Abstract

The invention discloses a dispersing agent for a concrete accelerator, a preparation method of the dispersing agent and the concrete accelerator, and the preparation method of the dispersing agent comprises the following steps: mixing a first monomer, a second monomer and a third monomer, and then reacting to obtain the dispersing agent, wherein the first monomer is selected from a styrene-maleic anhydride copolymer and / or a styrene-acrylic acid copolymer, the second monomer is selected from ethylenediamine and / or triethylene tetramine, and the third monomer is selected from chitosan. The dispersing agent is applied to the concrete accelerator, the rheological property of an accelerator system can be remarkably improved and optimized, and the dispersity and content of Al < 3 + > in the accelerator are improved, so that the accelerator system has the optimal setting time, and meanwhile, the effect that the set concrete has enough high strength and stability is ensured.

Description

Technical Field

[0001] The present application relates to a dispersant for a concrete accelerating agent, a preparation method thereof, and a concrete accelerating agent, belonging to the technical field of concrete accelerating agents. Background Art

[0002] A concrete accelerating agent is a chemical admixture that can cause cement or concrete to solidify rapidly, and can also be used as a coagulant to shorten the coagulation time of concrete slurry and accelerate the setting and hardening rate of shotcrete. Concrete accelerating agents are mainly used in shotcrete construction in scenarios such as tunnels, urban construction, water conservancy and hydropower culverts, diversion tunnels, industrial and mining construction, etc., and in shotcrete support for structural self-waterproofing, leak prevention, and plugging construction, rapid ground concrete construction, and concrete emergency rescue projects. One of the keys to shotcrete technology is the rapid development of early strength. Shotcrete at the initial stage of tunnel excavation plays a crucial role in controlling the deformation of surrounding rocks. Slow strength development not only affects the construction progress but also exposes construction operators to the risk of insufficient support strength.

[0003] Ordinary accelerating agents contain a large amount of alkaline substances. The introduction of alkaline substances will cause alkali-aggregate damage to concrete, and high chlorine content will also accelerate the corrosion of steel bars, significantly reducing the later strength and durability of shotcrete. Although the current alkali-free accelerating agents can improve the later strength and durability performance of shotcrete to a certain extent, they often fail to meet the high strength and durability requirements of engineering in actual engineering applications, and contain fluoride, which is extremely harmful to the human body and the environment. Currently, most are in the theoretical research stage and the market maturity is insufficient. In addition, due to serious dust during the construction process of powdered accelerating agents, it is not conducive to the health of personnel during construction in enclosed spaces, so solid powders are beginning to fade out of the market. The current alkali-free liquid accelerating agents are mainly aluminum sulfate systems, but due to the limited solubility and dispersibility of aluminum sulfate, a large amount of alkali-free liquid accelerating agent needs to be added during construction. Summary of the Invention

[0004] To solve the above problems, a dispersant for a concrete accelerating agent, a preparation method thereof, and a concrete accelerating agent are provided. This dispersant can strengthen the organic complexation during the preparation process of the accelerating agent and optimize the rheology of the accelerating agent, and can improve the dispersibility and content of Al 3+ in the accelerating agent. In addition, the present application also prepares an alkali-free, chlorine-free, and fluoride-free accelerating agent system with low viscosity and high strength, which can improve the early strength of concrete and optimize the setting time.

[0005] According to one aspect of the present application, a dispersant for a concrete accelerating agent is provided, and the chemical structural formula of the dispersant is:

[0006]

[0007] Among them, R 1 is selected from an ethylenediamine group or a triethylenetetramine group, and R 2 is selected from a maleic anhydride group or an acrylic acid group;

[0008] n is a positive integer between 1 and 10, m is a positive integer between 1 and 5, and p is a positive integer between 1 and 4.

[0009] Optionally, R 1 is selected from an ethylenediamine group, and R 2 is selected from a maleic anhydride group.

[0010] When this dispersant is applied to a concrete accelerating agent, it can significantly improve and optimize the rheology of the accelerating agent system, enhance the dispersibility and content of Al 3+ in the accelerating agent, so as to ensure that the accelerating agent system has the optimal setting time, and at the same time ensure that the solidified concrete has high enough strength and stability.

[0011] According to another aspect of the present application, a preparation method of a dispersant for a concrete accelerating agent is provided, which is characterized by including the following steps:

[0012] Mix the first monomer, the second monomer and the third monomer with an initiator and then react to obtain the dispersant;

[0013] Among them, the first monomer is selected from styrene-maleic anhydride copolymer and / or styrene-acrylic acid copolymer, the second monomer is selected from ethylenediamine and / or triethylenetetramine, and the third monomer is selected from chitosan.

[0014] The styrene-maleic anhydride copolymer or styrene-acrylic acid copolymer in the present application endows the dispersant with good hydrophilicity through its polar groups (such as carboxyl group, anhydride group), can stably disperse the aluminum salt precursor in an aqueous environment, prevent particle aggregation, and enhance the dispersing effect of Al 3+ in the aqueous phase. In addition, the styrene group provides a certain degree of hydrophobicity, so that the dispersant also has good dispersing ability in an oily medium. The amino group of ethylenediamine or triethylenetetramine undergoes a chemical reaction with the polar group in the copolymer, enhancing the stability of the dispersant in the aqueous phase, increasing the affinity with inorganic fillers, and providing the dispersant with the ability to bridge the aqueous phase and the oily phase, further enhancing its amphiphilic characteristics. As a natural polysaccharide, chitosan provides additional dispersibility and stability in an aqueous environment by virtue of its hydrophilicity and functional groups such as amino groups, and at the same time interacts with the components in the aqueous phase and the oily phase through its structure, improving the stability and adaptability of the dispersant. In addition, chitosan can also play an antibacterial role. The synergistic effect of the three enables the dispersant to be effectively dispersed in both aqueous and oily systems, significantly improving the adaptability, stability and performance of the dispersant.

[0015] Optionally, the molar ratio of the first monomer, the second monomer and the third monomer is 0.05 - 0.2:0.05 - 0.2:1;

[0016] Preferably, the molar ratio of the first monomer, the second monomer and the third monomer is 0.1:0.1:1.

[0017] By controlling the molar ratio of the three, the hydrophilicity, lipophilicity and stability of the dispersant can be precisely adjusted, thereby optimizing its performance. For example, increasing the proportion of styrene-maleic anhydride copolymer or styrene-acrylic acid copolymer can improve the hydrophilicity and dispersing ability of the dispersant; adjusting the proportion of ethylenediamine or triethylenetetramine helps to enhance the affinity and stability between the dispersant and inorganic fillers; while the proportion of chitosan determines the thickening property and water-phase stability of the dispersant. By precisely regulating the proportion of these monomers, it can be ensured that the dispersant can be effectively dispersed in both aqueous and oily systems, improving its comprehensive performance and adaptability in applications such as concrete accelerating agents.

[0018] Optionally, the first monomer is a styrene-maleic anhydride copolymer, the second monomer is ethylenediamine, and the third monomer is chitosan.

[0019] Optionally, the reaction temperature is 120 - 170 °C, preferably 140 °C; the reaction time is not less than 2 hours, preferably 3 hours.

[0020] Optionally, the preparation steps of the styrene-maleic anhydride copolymer include: mixing styrene, maleic anhydride or acrylic acid, and benzoyl peroxide and reacting to obtain a styrene-maleic anhydride copolymer or a styrene-acrylic acid copolymer, and then obtaining the styrene-maleic anhydride copolymer or the styrene-acrylic acid copolymer through alkaline hydrolysis.

[0021] Optionally, the molar ratio of styrene to maleic anhydride is: 1 - 2:1, preferably 1.5:1.

[0022] According to another aspect of the present application, there is provided a concrete accelerating agent, which comprises the following components in parts by weight: 0.5 - 2 parts of a dispersant, 0.5 - 2 parts of a graphene derivative, 50 - 60 parts of an aluminum salt, 5 - 8 parts of an organic regulator, 2 - 3 parts of an inorganic salt, 4 - 7 parts of a complexing stabilizer substance, and 30 - 35 parts of water, wherein the dispersant is selected from the above-mentioned dispersant or the dispersant prepared by the above-mentioned preparation method.

[0023] Among them, the organic regulator is a mixture of glycine and acrylic acid, and the complexing stabilizer is selected from at least one of diethanolamine, dimethylethanolamine and isopropanolamine.

[0024] In this application, the aluminum salt added to the accelerating admixture can accelerate the hydration reaction of cement, thereby promoting the rapid setting of concrete and enhancing the early strength of concrete. The graphene derivative, as a reinforcing agent, can not only enhance the strength and durability of concrete, but also further improve the accelerating effect of the accelerating admixture, and enhance the internal bonding force of cement particles through its unique structure. The dispersant can significantly improve the dispersibility of the aluminum salt, by increasing the solubility of Al 3+ in the accelerating admixture, ensuring the uniform distribution of aluminum ions in the cement paste, avoiding the aggregation and unstable reaction of the aluminum salt, and thus enhancing the effect of the accelerating admixture system. The organic regulator can effectively adjust the setting time of concrete, prevent the accelerating admixture from setting too quickly, and ensure the controllability of construction operations. The inorganic salt adjustment can regulate the rate of cement hydration reaction and enhance stability. The complexing stabilizer forms a stable complex with metal aluminum ions, avoids the unstable reaction of aluminum ions, prevents the precipitation of aluminum salts, maintains the uniform dispersion of aluminum ions in the solution, optimizes its role in the cement hydration process, and thus improves the reaction efficiency and long-term stability of the accelerating admixture system. Water, as a solvent, participates in the hydration reaction and regulates the workability and strength of concrete. Through the synergistic effect of these components, the accelerating admixture can improve the setting speed, strength and overall performance of concrete while ensuring stability, meeting the requirements of different projects.

[0025] The dispersant can significantly improve the dispersibility of the aluminum salt through the interaction of its molecular structure with the aluminum salt, increasing the solubility of Al 3+ in the accelerating admixture. Specifically, the polar groups in the dispersant interact with aluminum ions or other components in the aluminum salt, enhancing the solubility of the aluminum salt and reducing the electrostatic attraction between aluminum salt molecules, thus avoiding the aggregation or precipitation of the aluminum salt and improving its dispersibility in the cement paste. In addition, the amphiphilic structure of the dispersant can interact with polar molecules in the aqueous phase and oily or hydrophobic molecules. This property helps to reduce the cohesion between aluminum salt particles, making them uniformly dispersed in the aqueous environment and maintaining a stable colloidal state. In addition, the negatively charged dispersant reduces the attraction between aluminum salt particles through electrostatic repulsion, further enhancing its dispersibility. Therefore, the uniform distribution of aluminum ions in the cement paste is ensured, the aggregation of aluminum salts is avoided, and the effect of the accelerating admixture is enhanced.

[0026] Optionally, it comprises the following components in parts by weight: 1 part of dispersant, 1 part of graphene derivative, 55 parts of aluminum salt, 6 parts of organic regulator, 2.5 parts of inorganic salt, 5.5 parts of complexing stabilizer, and 30 parts of water.

[0027] Optionally, the aluminum salt is aluminum sulfate, the organic regulator is a mixture of glycine and acrylic acid with a mass ratio of 0.5 - 1:1, the complexing stabilizer is a mixture of diethanolamine, dimethylethanolamine, and isopropanolamine with a mass ratio of 1 - 2:10:2 - 3, and the inorganic salt is selected from calcium sulfate and / or iron sulfate.

[0028] Optionally, the graphene derivative can be graphene oxide or graphene, preferably graphene oxide, so as to further ensure the dispersibility of the graphene derivative in the accelerating agent system and ensure its uniform dispersion. Due to the unique two-dimensional nanostructure and abundant surface functional groups of graphene oxide, it can fill capillary pores in the range of 10 - 100 nm, optimize the pore structure distribution. For example, the proportion of harmful pores (>50 nm) can be reduced by 50%, forming a dense matrix. And the oxygen-containing functional groups on the surface of graphene oxide can attract Ca 2 +, induce the directional growth of C-S-H gel, form high-density hydration products, and then significantly improve the compressive and flexural strengths of concrete. Graphene oxide can physically block the migration paths of erosion ions such as Cl - , SO 4 2- to improve the durability of concrete.

[0029] The organic regulator of the present application can regulate the setting time and prevent rapid setting. Glycine in the organic regulator, as an amino acid, can act on calcium ions in cement particles through its amino group to inhibit the rapid hydration reaction of cement; while acrylic acid has strong hydrophilicity and weak acidity, and can form a stable complex by combining with calcium ions in cement, thereby regulating the rate of hydration reaction. The mixture of glycine and acrylic acid acts synergistically to effectively slow down the initial stage of cement hydration, increase the construction operation time of concrete, avoid strength loss and crack problems caused by rapid setting, and ensure the stability and construction quality of concrete under different environmental conditions.

[0030] The complexing stabilizer of the present application can avoid unstable reactions. Diethanolamine, dimethylethanolamine, and isopropanolamine in the complexing stabilizer form stable complexes with aluminum ions through amino or hydroxyl groups, enhance the dispersibility and stability of aluminum ions, avoid adverse reactions, and improve the overall performance of the accelerating agent. At the same time, these complexing stabilizers regulate the activity of aluminum ions, optimize the rate of cement hydration reaction, and ensure the long-term effectiveness and high-efficiency setting effect of the accelerating agent.

[0031] The beneficial effects of the present application include but are not limited to:

[0032] 1. According to the dispersant of the present application, when applied to a concrete accelerating agent, it can significantly improve and optimize the rheology of the accelerating agent system, enhance Al 3+Dispersibility and content in the accelerator, so as to ensure that the accelerator system has the optimal setting time, and at the same time ensure that the set concrete has sufficiently high strength and stability.

[0033] 2. According to the dispersant of the present application, through the synergistic effect of styrene-maleic anhydride copolymer, ethylenediamine, and chitosan, the dispersant can be effectively dispersed in both aqueous and oily systems, significantly improving the adaptability, stability, and performance of the dispersant.

[0034] 3. According to the accelerator of the present application, the dispersant can be uniformly dispersed therein, improving the reaction efficiency and long-term stability of the accelerator system. At the same time, it can optimize the setting time of the concrete, improve the early strength of the concrete, and ensure the stability and overall performance of the concrete. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The schematic embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation to the present application. In the drawings:

[0036] Figure 1 SEM image of the set concrete sample when using the accelerator of Example 1 in the present application;

[0037] Figure 2 SEM image of the set concrete sample when using the commercially available accelerator of Comparative Example D9 in the present application.

[0038] Figure 3 State diagram of the accelerator of some embodiments in the present application after being placed for 1 week. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0039] The present application will be described in detail below with reference to the embodiments, but the present application is not limited to these embodiments.

[0040] Unless otherwise specified, the raw materials and catalysts in the embodiments of the present application are purchased through commercial channels.

[0041] Example 1

[0042] The preparation steps of dispersant 1# are as follows:

[0043] (1) Styrene and maleic anhydride with a molar ratio of 1.5:1 are mixed evenly, and under the initiation of benzoyl peroxide, the temperature is raised to 80°C and reacted for 1 h. After cooling, the product is filtered and vacuum dried at 60°C to obtain styrene-maleic anhydride copolymer;

[0044] (2) Styrene-maleic anhydride copolymer, ethylenediamine, and chitosan with a molar ratio of 0.1:0.1:1 are mixed evenly, and after the temperature is raised to 140°C and reacted for 3 hours, dispersant 1# is obtained;

[0045] The chemical structural formula of dispersant 1# is:

[0046]

[0047] n is a positive integer between 1 and 10, m is a positive integer between 1 and 5, and p is a positive integer between 1 and 4;

[0048] The preparation steps of the quick-setting agent 1# are as follows:

[0049] Take 1 g of dispersant 1#, 1 g of graphene oxide, 55 g of aluminum sulfate, 2 g of glycine, 4 g of acrylic acid, 2.5 g of calcium sulfate, 0.8 g of diethanolamine, 4 g of dimethylethanolamine, 1.2 g of isopropanolamine and 30 g of water, and continuously stir for 18 h to obtain the quick-setting agent 1#.

[0050] Example 2#

[0051] The preparation steps of dispersant 2# are as follows:

[0052] (1) Mix styrene and acrylic acid with a molar ratio of 1.5:1 evenly, and under the initiation of benzoyl peroxide, heat up to 80 °C and react for 1 h. After cooling, filter the product and vacuum dry it at 60 °C to obtain styrene-acrylic acid copolymer;

[0053] (2) Mix the styrene-acrylic acid copolymer, triethylenetetramine and chitosan with a molar ratio of 0.1:0.1:1 evenly, heat up to 140 °C and react for 3 hours to obtain dispersant 2#.

[0054] The difference between the preparation steps of the quick-setting agent 2# and those of the quick-setting agent 1# is that dispersant 1# is replaced by dispersant 2#, and the other steps are the same as those of the quick-setting agent 1# to obtain the quick-setting agent 2#.

[0055] Example 3

[0056] The preparation steps of dispersant 3# are as follows:

[0057] (1) Mix styrene and maleic anhydride with a molar ratio of 1:1 evenly, and under the initiation of benzoyl peroxide, heat up to 80 °C and react for 1 h. After cooling, filter the product and vacuum dry it at 60 °C to obtain styrene-maleic anhydride copolymer;

[0058] (2) Mix the styrene-maleic anhydride copolymer, triethylenetetramine and chitosan with a molar ratio of 0.05:0.05:1 evenly, heat up to 140 °C and react for 3 hours to obtain dispersant 3#.

[0059] The preparation steps of the quick-setting agent 3# are different from those of the quick-setting agent 1# in that the dispersant 1# is replaced by the dispersant 3#, and the remaining steps are the same as those of the quick-setting agent 1# to obtain the quick-setting agent 3#.

[0060] Example 4

[0061] The preparation steps of the dispersant 4# are as follows:

[0062] (1) Styrene and maleic anhydride with a molar ratio of 3:1 are mixed evenly, and under the initiation of benzoyl peroxide, the temperature is raised to 80 °C and reacted for 1 h. After cooling, the product is filtered and vacuum dried at 60 °C to obtain styrene-maleic anhydride copolymer;

[0063] (2) The styrene-maleic anhydride copolymer, triethylenetetramine and chitosan with a molar ratio of 0.2:0.2:1 are mixed evenly, and after the temperature is raised to 160 °C, the reaction is carried out for 4 hours to obtain the dispersant 4#.

[0064] The preparation steps of the quick-setting agent 4# are different from those of the quick-setting agent 1# in that the dispersant 1# is replaced by the dispersant 4#, and the remaining steps are the same as those of the quick-setting agent 1# to obtain the quick-setting agent 4#.

[0065] Example 5

[0066] The preparation steps of the quick-setting agent 5# are as follows:

[0067] Take 2 g of dispersant 1#, 2 g of graphene oxide, 50 g of aluminum sulfate, 2.5 g of glycine, 5 g of acrylic acid, 2 g of calcium sulfate, 0.6 g of diethanolamine, 3 g of dimethylethanolamine, 0.9 g of isopropanolamine and 30 g of water, and continuously stir for 18 h to obtain the quick-setting agent 5#.

[0068] Example 6

[0069] The preparation steps of the quick-setting agent 6# are as follows:

[0070] Take 2 g of dispersant 1#, 2 g of graphene oxide, 50 g of aluminum sulfate, 3 g of glycine, 3 g of acrylic acid, 2 g of calcium sulfate, 0.6 g of diethanolamine, 3 g of dimethylethanolamine, 0.9 g of isopropanolamine and 30 g of water, and continuously stir for 18 h to obtain the quick-setting agent 6#.

[0071] Comparative example D1

[0072] The preparation steps of the quick-setting agent D1# are different from those of the quick-setting agent 1# in that in step (2), the styrene-maleic anhydride copolymer and ethylenediamine with a molar ratio of 0.1:0.1 are mixed evenly, and after the temperature is raised to 160 °C, the reaction is carried out for 4 hours to obtain the dispersant D1#.

[0073] The preparation steps of accelerator D1# are different from those of accelerator 1# in that dispersant 1# is replaced by dispersant D1#, and the remaining steps are the same as those of accelerator 1# to obtain accelerator D1#.

[0074] Comparative example D2

[0075] The preparation steps of accelerator D2# are different from those of accelerator 1# in that in step (2), after uniformly mixing styrene-maleic anhydride copolymer and chitosan with a molar ratio of 0.1:1, the temperature is raised to 160 °C and reacted for 4 hours to obtain dispersant D2#.

[0076] The preparation steps of accelerator D2# are different from those of accelerator 1# in that dispersant 1# is replaced by dispersant D2#, and the remaining steps are the same as those of accelerator 1# to obtain accelerator D2#.

[0077] Comparative example D3

[0078] The preparation steps of accelerator D3# are different from those of accelerator 1# in that dispersant 1# is not added, and the remaining steps are the same as those of accelerator 1# to obtain accelerator D3#.

[0079] Comparative example D4

[0080] The preparation steps of accelerator D4# are different from those of accelerator 1# in that the organic regulator is not added, and the remaining steps are the same as those of accelerator 1# to obtain accelerator D4#.

[0081] Comparative example D5

[0082] The preparation steps of accelerator D5# are different from those of accelerator 1# in that the complexing stabilizer is not added, and the remaining steps are the same as those of accelerator 1# to obtain accelerator D5#.

[0083] Comparative example D6

[0084] The preparation steps of accelerator D6# are different from those of accelerator 1# in that graphene oxide is not added, and the remaining steps are the same as those of accelerator 1# to obtain accelerator D6#.

[0085] Comparative example D7

[0086] The preparation steps of accelerator D7# are as follows:

[0087] Take 3 g of dispersant 1#, 0.3 g of graphene oxide, 70 g of aluminum sulfate, 5 g of glycine, 5 g of acrylic acid, 2 g of calcium sulfate, 0.6 g of diethanolamine, 3 g of dimethylethanolamine, 0.9 g of isopropanolamine and 30 g of water, and continuously stir for 18 h to obtain accelerator D7#.

[0088] Comparative Example D8

[0089] The difference in the preparation steps of the quick-setting agent D8# from those of the quick-setting agent 1# lies in that no dispersant and graphene oxide are added, and the remaining steps are the same as those of the quick-setting agent 1#, thus obtaining the quick-setting agent D8#.

[0090] Comparative Example D9

[0091] The quick-setting agent D9# uses a commercially available quick-setting agent.

[0092] Experimental Example

[0093] According to the "Technical Specification for Application of Shotcrete" JGJ / T372 - 2016, the strength performance of the shotcrete mixed with the quick-setting agents 1# - 6# and the quick-setting agents D1# - D9# of the present invention was tested. The test results are shown in Table 1. The cement used in the test was P.O 42.5 cement produced by Conch, and the water reducer was a polycarboxylate superplasticizer produced by the partner. The dosage of the quick-setting agent in the present invention was 8% of the cement mass.

[0094] Table 1

[0095]

[0096]

[0097] It can be seen from Table 1 that in Example 1, by optimizing the ratio between various components and adding the dispersant 1#, it is ensured that the concrete has a suitable initial setting time and final setting time, and at the same time, it can avoid the loss of cement strength caused by too fast setting, and ensure the strength stability and construction quality of the concrete in different environments.

[0098] In addition, Figure 1 Figure [ID] is the SEM image of the solidified concrete sample when using the quick-setting agent 1# of Example 1 in this application. Figure 2 Figure [ID] is the SEM image of the solidified concrete sample when using the commercially available quick-setting agent D9# of Comparative Example D9 in this application. It can be seen from the figure that due to the presence of graphene oxide and the dispersant in the quick-setting agent 1#, the crystal phase of the concrete solidified with the quick-setting agent 1# is very tight and orderly, so the compressive and flexural strengths of the concrete are higher, while the crystal phase of the concrete solidified with the ordinary commercially available quick-setting agent D9# is relatively loose and disorderly.

[0099] Figure 3This is a picture of the quick-setting agent after being placed for 1 week in the embodiments of this application. From left to right, they are quick-setting agent D8# (without adding graphene oxide, without adding dispersant), quick-setting agent D3# (without adding dispersant), quick-setting agent D6# (without adding graphene oxide), and quick-setting agent 1. It can be seen from the figure that the quick-setting agents without adding dispersant are severely layered, indicating that the components in the quick-setting agent are not evenly dispersed in the solvent, and the graphene shows an agglomeration phenomenon, indicating that the quick-setting agent system without adding dispersant is relatively unstable; the quick-setting agent with the added dispersant is still evenly dispersed after being placed for one week, without aggregation, and the graphene oxide is evenly dispersed in the system, indicating that this dispersant can significantly improve the dispersibility of graphene oxide and aluminum salt, and enhance the long-term stability of the quick-setting agent system.

[0100] As mentioned above, the above are only the embodiments of this application. The protection scope of this application is not limited by these specific embodiments, but is determined by the claims of this application. For those skilled in the art, various changes and modifications can be made to this application. Any modification, equivalent replacement, improvement, etc. made within the technical idea and principle of this application shall be included within the protection scope of this application.

Claims

1. A dispersant for a concrete accelerating agent, characterized in that: The chemical structural formula of the dispersant is: wherein R1 is selected from ethylenediamine group or triethylenetetramine group, and R2 is selected from maleic anhydride group or acrylic acid group; n is a positive integer between 1 and 10, m is a positive integer between 1 and 5, and p is a positive integer between 1 and 4.

2. The dispersant for concrete accelerating agent according to claim 1, characterized in that: R1 is selected from ethylenediamine groups, and R2 is selected from maleic anhydride groups.

3. A method for preparing a dispersant for a concrete accelerating agent, characterized in that: The following steps are involved: The first monomer, the second monomer and the third monomer are mixed and reacted to obtain the dispersant; The first monomer is selected from styrene-maleic anhydride copolymer and / or styrene-acrylic acid copolymer, the second monomer is selected from ethylenediamine and / or triethylenetetramine, and the third monomer is selected from chitosan.

4. The method for preparing a dispersant for a concrete accelerating agent according to claim 3, characterized in that: The molar ratio of the first monomer, the second monomer and the third monomer is 0.05-0.2:0.05-0.2:1; Preferably, the molar ratio of the first monomer, the second monomer and the third monomer is 0.1:0.1:

1.

5. The method for preparing a dispersant for a concrete accelerating setting agent according to claim 3, characterized in that: The first monomer is styrene-maleic anhydride copolymer, the second monomer is ethylenediamine, and the third monomer is chitosan.

6. The method for preparing a dispersant for a concrete accelerating agent according to claim 3, characterized in that: The reaction temperature is 120-170°C, preferably 140°C; the reaction time is not less than 2 hours, preferably 3 hours.

7. The method for preparing a dispersant for a concrete accelerating agent according to claim 3, characterized in that: The preparation steps of the styrene-maleic anhydride copolymer include: mixing styrene, maleic anhydride or acrylic acid, and benzoyl peroxide to react to obtain a styrene-maleic anhydride copolymer or a styrene-acrylic acid copolymer, and then performing alkaline hydrolysis to obtain the styrene-maleic anhydride copolymer or the styrene-acrylic acid copolymer; Preferably, the molar ratio of styrene to maleic anhydride is 1-2:1, preferably 1.5:

1.

8. A concrete accelerating agent, characterized in that: It comprises the following components in parts by weight: 0.5-2 parts of a dispersant, 0.5-2 parts of a graphene derivative, 50-60 parts of an aluminum salt, 5-8 parts of an organic regulator, 2-3 parts of an inorganic salt, 4-7 parts of a complex stabilizer substance, and 30-35 parts of water, wherein the dispersant is selected from the dispersant described in claim 1 or 2 or the dispersant prepared by the preparation method described in any one of claims 3 to 7; Wherein, the organic regulator is a mixture of glycine and acrylic acid, and the complex stabilizer is selected from at least one of diethanolamine, dimethylethanolamine and isopropanolamine.

9. The concrete accelerating agent according to claim 8, characterized in that: The invention comprises the following components in parts by weight: 1 part of dispersant, 1 part of graphene derivative, 55 parts of aluminum salt, 6 parts of organic regulator, 2.5 parts of inorganic salt, 6 parts of complex stabilizer and 30 parts of water.

10. The concrete accelerating agent according to claim 8, characterized in that: The aluminum salt is aluminum sulfate, the organic regulator is a mixture of glycine and acrylic acid in a mass ratio of 0.5-1:1, the complex stabilizer is a mixture of diethanolamine, dimethylethanolamine and isopropanolamine in a mass ratio of 1-2:10:2-3, and the inorganic salt is selected from calcium sulfate and / or ferric sulfate.

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