C6 monomer polycarboxylate superplasticizer and preparation method thereof

Abstract

The invention discloses a C6 monomer polycarboxylate superplasticizer and a preparation method thereof. The C6 monomer polycarboxylate superplasticizer is prepared from the following raw materials in parts by mass: 300-380 parts of C6 ethylene glycol monovinyl polyglycol ether polyether macromonomer, 7.5-11.0 parts of acrylic acid, 0.3-1 part of chain transfer agent, 0.15-1.0 part of reducing agent and 0.6-1.2 parts of oxidizing agent. The water reducing agent prepared by the invention has the advantages of simple process, energy conservation, environmental protection, shortened synthesis time, improved production efficiency, high adaptability and better water reducing property.

Description

Technical Field

[0001] The present invention relates to the technical field of concrete additives, and in particular to a C6 monomer polycarboxylate water reducer and a preparation method thereof. Background Art

[0002] With the continuous expansion of infrastructure construction in my country, the use of polycarboxylate superplasticizers (PCSs) in the construction of high-rise buildings, dams, bridges, railway networks, highway networks, tunnels, and other applications has also continued to increase, making them an indispensable component of concrete. However, traditional PCSs are highly sensitive to the mud content of sand and gravel (clay adsorption reduces dispersibility), have poor compatibility with cementitious materials (especially low-quality fly ash and high-alkali cement), and have limited compatibility with composites (for example, incompatibility with naphthalene-based PCSs). As a result, they cannot meet the complexity and application requirements of current applications.

[0003] With the emergence of 6-carbon macromonomers, unlike traditional 3-, 4-, and 5-carbon macromonomers, the unsaturated double bonds in these 6-carbon macromonomers are more reactive, require less energy, and are more susceptible to polymerization. Furthermore, since the double bonds in these 6-carbon macromonomers are monosubstituted, the steric resistance to the swinging of the polyether side chains is further reduced, allowing them to swing more freely and with a wider range of motion. This increased freedom of swing improves the wrapping and entanglement properties of the polyether side chains, resulting in a polycarboxylate water-reducing agent with enhanced slump retention and adaptability, particularly effective for applications involving low-quality sand and gravel with high mud content. The high reactivity of the double bonds in these 6-carbon macromonomers facilitates the copolymerization chain growth reaction, significantly shortening the addition time of acrylic acid, requiring only 120 minutes for the complete reaction, thus significantly improving the production efficiency of polycarboxylate water-reducing agents. While waiting for industry recognition, the cost of 6-carbon large monomers has also been greatly controlled, and is basically the same as 4-carbon and 5-carbon. Under such circumstances, the development of a C6 monomer polycarboxylic acid water reducer and its new process is of great significance to the development of the concrete admixture industry. Summary of the Invention

[0004] The present invention discloses a C6 monomer polycarboxylate water reducer and a preparation method thereof. The C6 monomer polycarboxylate water reducer has high adaptability, can cope with complex scene requirements, has a simple process, and is energy-saving and environmentally friendly.

[0005] In order to achieve the above technical effects, the present invention adopts the following technology: a C6 monomer polycarboxylic acid water reducer, comprising the following raw materials in parts by weight: 300-380 parts of C6 ethylene glycol monovinyl polyethylene glycol ether polyether macromonomer, 7.5-11.0 parts of acrylic acid, 0.3-1 parts of chain transfer agent, 0.15-1.0 parts of reducing agent, and 0.6-1.2 parts of oxidant.

[0006] The specific preparation method includes: S1, taking ethylene glycol monovinyl polyethylene glycol ether C6 polyether macromonomer in proportion and stirring to dissolve; S2, taking acrylic acid in proportion, adding a certain amount of deionized water and stirring to dissolve to form drop A; S3, taking a chain transfer agent and a reducing agent in proportion, adding a certain amount of deionized water, stirring and dissolving to form a droplet B; S4, adding a measured amount of oxidant to the dissolved ethylene glycol monovinyl polyglycol ether C6 polyether macromonomer and stirring for 10 minutes; S5, simultaneously and uniformly adding droplets A and B to the solution formed in step S4, continuously adding droplets A for 50 minutes and continuously adding droplets B for 60 minutes; S6: After completing S5, keep warm for 1 hour.

[0007] Preferably, the chain transfer agent is any one of mercaptopropionic acid, mercaptoethanol or sodium hypophosphite.

[0008] Preferably, the reducing agent is any one of vitamin C, Diaobaikuai, and Liruoyang R128.

[0009] Preferably, the oxidant is any one of hydrogen peroxide, potassium persulfate, and ammonium persulfate.

[0010] Compared with existing technologies, the present invention has a novel structure, a simple synthesis process, energy conservation and environmental protection, shortened synthesis time, and improved production efficiency. Furthermore, the double bond of the ethylene glycol monovinyl polyglycol ether macromonomer selected in this study is a monosubstituted structure, which further reduces the steric resistance to the swing of the polyether side chain, allowing the polyether side chain to swing more freely and with a larger range of motion. The increased degree of freedom of the polyether side chain swing improves the wrapping and entanglement properties of the polyether side chain, resulting in a synthesized polycarboxylate water-reducing agent with higher slump retention and adaptability, and is particularly effective in treating sand and gravel materials with poor quality and high mud content. DETAILED DESCRIPTION

[0011] The present invention discloses a C6 monomer polycarboxylate water-reducing agent and a preparation method thereof, which are characterized by high efficiency and environmental protection. To facilitate understanding by those skilled in the art, the following is further described in parts by mass with reference to specific examples. Example

[0012] A C6 monomer polycarboxylic acid water reducer comprises the following components: 300 parts of C6 ethylene glycol monovinyl polyethylene glycol ether polyether macromonomer, 7.5 parts of acrylic acid, 0.3 parts of a chain transfer agent, 0.15 parts of a reducing agent, and 0.6 parts of an oxidizing agent. The specific preparation method is as follows: S1. First, 300 parts of ethylene glycol monovinyl polyethylene glycol ether C6 polyether macromonomer are taken and stirred to dissolve.

[0013] S2, then, 7.5 parts of acrylic acid and 20 parts of deionized water are stirred and dissolved to form droplets A.

[0014] S3, then stirring and dissolving 0.15 parts of bleaching powder, 0.3 parts of mercaptopropionic acid and 25 parts of deionized water to form drop B.

[0015] S4, adding 0.6 parts of hydrogen peroxide to the dissolved ethylene glycol monovinyl polyethylene glycol ether C6 polyether macromonomer and stirring for 10 minutes.

[0016] S5, simultaneously and uniformly adding droplets A and B to the solution formed in step S4, continuously adding droplets A for 50 minutes, and continuously adding droplets B for 60 minutes.

[0017] S6: After the addition is completed, keep warm for 1 hour. Example

[0018] A C6 monomer polycarboxylic acid water reducer comprises the following components: 350 parts of C6 ethylene glycol monovinyl polyethylene glycol ether polyether macromonomer, 10 parts of acrylic acid, 0.75 parts of a chain transfer agent, 0.7 parts of a reducing agent, and 0.95 parts of an oxidizing agent. The specific preparation method is as follows: S1, first, take 350 parts of ethylene glycol monovinyl polyethylene glycol ether C6 polyether macromonomer and stir and dissolve them.

[0019] S2, then, 10 parts of acrylic acid and 20 parts of deionized water are stirred and dissolved to form droplets A.

[0020] S3, then stirring and dissolving 0.75 parts of vitamin C, 0.7 parts of mercaptoethanol and 25 parts of deionized water to form drop B.

[0021] S4, adding 0.95 parts of potassium persulfate to the dissolved ethylene glycol monovinyl polyethylene glycol ether C6 polyether macromonomer and stirring for 10 minutes.

[0022] S5, simultaneously and uniformly adding droplets A and B to the solution formed in step S4, continuously adding droplets A for 50 minutes, and continuously adding droplets B for 60 minutes.

[0023] S6: After the addition is completed, keep warm for 1 hour. Example

[0024] A C6 monomer polycarboxylic acid water reducer comprises the following components: 380 parts of C6 ethylene glycol monovinyl polyethylene glycol ether polyether macromonomer, 11 parts of acrylic acid, 1 part of chain transfer agent, 1 part of reducing agent, and 1.2 parts of oxidant. The specific preparation method is as follows: S1. First, 380 parts of ethylene glycol monovinyl polyethylene glycol ether C6 polyether macromonomer are taken and stirred to dissolve.

[0025] S2, then, 11 parts of acrylic acid and 20 parts of deionized water are stirred and dissolved to form droplets A.

[0026] S3, then stir and dissolve 1 part of bleaching powder, 1 part of sodium hypophosphite and 25 parts of deionized water to form drop B.

[0027] S4, adding 1.2 parts of ammonium persulfate to the dissolved ethylene glycol monovinyl polyethylene glycol ether C6 polyether macromonomer and stirring for 10 minutes.

[0028] S5, simultaneously and uniformly adding droplets A and B to the solution formed in step S4, continuously adding droplets A for 50 minutes, and continuously adding droplets B for 60 minutes.

[0029] S6: After the addition is completed, keep warm for 1 hour.

[0030] In the above three embodiments, after obtaining the copolymer, the pH value is adjusted to between 6.0 and 7.0 using an alkaline substance to obtain a water reducing agent.

[0031] The water-reducing agent prepared by the present invention was tested for paste flowability according to GB / T8076-2008, "Test Method for Homogeneity of Concrete Admixtures." The cement used was a standard cement. Specifically, a water-cement ratio (W / C) of 0.29 was used, and the water-reducing agent content was 0.12% of the cement content. The standard cement used was the standard cement. The paste flowability test formula was as follows: 300.0 g of cement, 87.0 g of water, and 0.8 g of the admixture content. The mortar water reduction rate test formula was as follows: 450.0 g of cement, 1350.0 g of standard sand, and a water-reducing agent content of 0.25% of the water content. The test results are shown in Table 1.

[0032]

[0033] As can be seen from Table 1, the net slurry fluidity and time loss of the samples prepared in this embodiment are significantly changed compared with the company's polycarboxylic acid water reducer. The test results of the mortar water reduction rate show that the water reducer prepared in Examples 1-4 of the present invention has a better water reduction rate.

[0034] The water-reducing agent prepared by the present invention was subjected to an adaptability comparison test with the conventional water-reducing agent of the company, and the results are shown in Table 2.

[0035]

[0036] It can be seen from Table 2 that the net slurry fluidity and time loss of the samples prepared in the embodiments of the present invention are compared with the company's conventional water reducers. The net slurry fluidity and mortar water reduction rate of the samples prepared by adding the water reducers prepared in Examples 1-3 of the present invention are improved. The test results show that the water reducer prepared in the present invention has better adaptability.

Claims

1. A C6 monomer polycarboxylate water reducer, characterized in that: The method comprises the following raw materials in parts by weight: 300-380 parts of C6 ethylene glycol monovinyl polyethylene glycol ether polyether macromonomer, 7.5-11.0 parts of acrylic acid, 0.3-1 parts of a chain transfer agent, 0.15-1.0 parts of a reducing agent, and 0.6-1.2 parts of an oxidizing agent.

2. A C6 monomer polycarboxylate water reducer according to claim 1, characterized in that: The chain transfer agent is mercaptopropionic acid, mercaptoethanol or sodium hypophosphite.

3. A C6 monomer polycarboxylate water reducer according to claim 1, characterized in that: The reducing agent is one of vitamin C and diatomite.

4. A C6 monomer polycarboxylate water reducer according to claim 1, characterized in that: The oxidant is one of hydrogen peroxide, potassium persulfate and ammonium persulfate.

5. A method for preparing the C6 monomer polycarboxylate water-reducing agent according to any one of claims 1 to 4, characterized in that: The steps include: S1, taking ethylene glycol monovinyl polyethylene glycol ether C6 polyether macromonomer in proportion and stirring to dissolve; S2, taking acrylic acid in proportion, adding a certain amount of deionized water and stirring to dissolve to form drop A; S3, taking a chain transfer agent and a reducing agent in proportion, adding a certain amount of deionized water, stirring and dissolving to form a droplet B; S4, adding a measured amount of oxidant to the dissolved ethylene glycol monovinyl polyglycol ether C6 polyether macromonomer and stirring for 10 minutes; S5, simultaneously and uniformly adding droplets A and B to the solution formed in step S4, continuously adding droplets A for 50 minutes and continuously adding droplets B for 60 minutes; S6: After completing S5, keep warm for 1 hour.

6. The method for preparing a C6 monomer polycarboxylate water reducer according to claim 5, characterized in that: The mass ratio of the quantitative deionized water to the acrylic acid added in S3 is 20:7.5-11.

0.

7. The method for preparing a C6 monomer polycarboxylate water reducer according to claim 5, characterized in that: The mass ratio of the quantitative deionized water added in S3 to the chain transfer agent and the reducing agent is 25: 0.3-1.0: 0.15-1.0.

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