A polycarboxylic acid high-performance water reducing agent special for wind power tower cylinder segments and a preparation method thereof

Abstract

The present application relates to the technical field of concrete admixtures, and particularly relates to a polycarboxylic high-performance water-reducing agent for wind power tower cylinder segments and a preparation method thereof. The water-reducing agent is polymerized from an unsaturated macromonomer, an unsaturated carboxylic acid and / or an unsaturated carboxylic anhydride, and a foam control function monomer under the action of an initiator and a molecular weight regulator; the foam control function monomer is an unsaturated carboxylic ester silicone oil. The unsaturated carboxylic ester silicone oil is chemically bonded to the polycarboxylic molecular main chain, providing steric hindrance to enhance the water-reducing effect in the initial stage of concrete, and the low-molecular-weight side chain in the molecular structure improves the viscosity reduction performance. In the alkaline hydration process, the ester bond is hydrolyzed to release silicone oil in situ to play a defoaming role, effectively eliminating harmful pores and apparent bubbles in concrete, so that the surface of the wind power tower cylinder segment is smooth and bubble-free after demolding, and the water-reducing agent has the advantages of high water-reducing rate, significant strengthening effect, simple preparation process, and the like, and is particularly suitable for UHPC ultra-high performance concrete segments.

Description

Technical Field

[0001] The present invention relates to the technical field of concrete admixtures, and particularly relates to a special polycarboxylate high-performance water reducer for wind power tower segments and a preparation method thereof. Background Art

[0002] Driven by goals such as huge market demand, the market for wind power tower segments shows a strong growth trend and the overall outlook is optimistic.

[0003] As the height of wind power towers continues to climb, the requirements for material properties are constantly increasing. Currently, mass production applications of C80 - C105 high-strength concrete segments and UHPC (Ultra-High Performance Concrete, with a strength of 130 - 150) segments have been achieved. UHPC materials possess high tensile strength, high elastic modulus, and strain hardening characteristics, perfectly solving the performance contradictions of traditional materials.

[0004] However, due to the characteristics of UHPC such as low water-binder ratio and ultra-high strength, UHPC is prone to problems such as high viscosity and difficulty in meeting the strength standard. Therefore, to prepare UHPC for wind power tower segments with excellent performance, a special polycarboxylate high-performance water reducer for wind power tower segments with outstanding water-reducing, strength-enhancing, and viscosity-reducing effects is essential. At the same time, after the wind power tower segments are demolded, the surface is required to be smooth without obvious or hidden bubbles. Therefore, the special polycarboxylate high-performance water reducer for wind power tower segments also needs to effectively control the apparent bubbles on the premise of ensuring the workability and durability of the concrete. Summary of the Invention

[0005] To solve the deficiencies of the prior art, a special polycarboxylate high-performance water reducer for wind power tower segments provided by the present invention is polymerized from unsaturated monomers under the action of an initiator and a molecular weight regulator; wherein, the unsaturated monomers include unsaturated macromonomers, unsaturated small monomers, and enhanced foam control functional monomers; The enhanced foam control functional monomer is unsaturated carboxylic acid ester silicone oil; the unsaturated small monomer is unsaturated carboxylic acid and / or unsaturated carboxylic anhydride.

[0006] Further, the mass ratio of the unsaturated macromonomer, unsaturated small monomer, and enhanced foam control functional monomer is 200:(5 - 60):a, where 0 < a ≤ 5; the dosage of the initiator is 0.5% - 6.0% of the total mass of the unsaturated monomers; the dosage of the molecular weight regulator is 0.2% - 3.0% of the total mass of the unsaturated monomers.

[0007] Furthermore, the unsaturated carboxylic acid ester silicone oil has a molecular weight of 200-600 and is selected from at least one of single-terminal acrylate silicone oil, side-chain acrylate modified silicone oil, single-terminal methacrylate silicone oil, and side-chain methacrylate modified silicone oil.

[0008] Furthermore, the unsaturated macromonomer has a molecular weight of 400 to 6000 and is selected from at least one of 3-methyl-3-butene-1-polyethylene glycol, 2-methylallyl polyethylene glycol, ethylene glycol monovinyl polyethylene glycol ether, 4-hydroxybutylvinyl polyoxyethylene ether, polyethylene glycol monomethyl ether acrylate, and polyethylene glycol monomethyl ether methacrylate. The unsaturated carboxylic acid and / or unsaturated carboxylic anhydride is at least one of acrylic acid, methacrylic acid, and maleic anhydride.

[0009] Furthermore, the unsaturated macromonomer contains a mass fraction greater than 10% of a low molecular weight polyether monomer, wherein the low molecular weight polyether monomer has a molecular weight of 400 to 1500 and is selected from at least one of 3-methyl-3-butene-1-polyethylene glycol, 2-methylallyl polyethylene glycol, ethylene glycol monovinyl polyethylene glycol ether, 4-hydroxybutylvinyl polyoxyethylene ether, polyethylene glycol monomethyl ether acrylate, and polyethylene glycol monomethyl ether methacrylate.

[0010] Furthermore, the initiator is selected from at least one of the following: a combination of hydrogen peroxide and ascorbic acid, a combination of hydrogen peroxide and phytic acid, a combination of hydrogen peroxide and sodium formaldehyde sulfoxylate, a combination of hydrogen peroxide and BRUGGOLITE E51, a combination of hydrogen peroxide and ascorbic acid and ferrous sulfate, a combination of hydrogen peroxide and phytic acid and ferrous sulfate, a combination of hydrogen peroxide and sodium formaldehyde sulfoxylate and ferrous sulfate, a combination of hydrogen peroxide and BRUGGOLITE E51 and ferrous sulfate, and ammonium persulfate.

[0011] Furthermore, the molecular weight regulator is selected from at least one of mercaptoacetic acid, mercaptoethanol, mercaptopropionic acid, sulfonated mercaptopropionic acid, and sodium hypophosphite.

[0012] Furthermore, the polymerization process includes: adding an aqueous solution of an initiator, an aqueous solution of a molecular weight regulator, and an aqueous solution of unsaturated carboxylic acid and / or unsaturated carboxylic anhydride to the reaction system dropwise over 0.5 to 3 hours, at a reaction temperature of 5 to 90°C, and maintaining the temperature for 0.5 to 1 hour after the addition is complete.

[0013] Optionally, a portion of the initiator and / or molecular weight regulator may be added to the substrate beforehand, with the remainder added dropwise.

[0014] It should be noted that the initiator and / or molecular weight regulator can be added entirely to the reaction system dropwise, or a portion of the initiator and / or molecular weight regulator can be pre-added to the substrate, with the remainder prepared as an aqueous solution and added dropwise during the polymerization reaction. Those skilled in the art can flexibly adjust the addition method of the initiator and molecular weight regulator according to the actual polymerization reaction activity and process operation requirements, all of which fall within the scope of protection of this invention.

[0015] This invention also provides a method for preparing a high-performance polycarboxylate superplasticizer for wind turbine tower segments as described above, comprising the following steps: The base material is obtained by mixing unsaturated macromonomers, monomers that enhance foam control, and water. Unsaturated monomers, initiators, and molecular weight regulators are added dropwise to the substrate to carry out a polymerization reaction, thereby obtaining a copolymer product; Add alkali to the copolymer to adjust the pH value to 5-7, or collect the product directly without adding alkali, to obtain the special polycarboxylate high-performance water-reducing agent for wind turbine tower tube segments.

[0016] The dropping time is 0.5 to 3 hours, the initial reaction temperature is 10 to 90°C, the material temperature during the dropping process is 10 to 90°C, and the temperature is kept warm for 0.5 to 1 hour after the dropping is completed.

[0017] Optionally, the initiator, molecular weight regulator, and unsaturated monomer are added dropwise in their aqueous solutions.

[0018] Compared with existing technologies, the polycarboxylate superplasticizer for wind turbine tower segments provided by this invention introduces unsaturated carboxylate ester silicone oil as a monomer to enhance foam control function into the molecular structure of the polycarboxylate superplasticizer. During the polymerization reaction, it is chemically bonded to the main chain of the superplasticizer. In the early stage of concrete mixing, the steric hindrance provided by the silicone oil structure significantly enhances the dispersion ability of the polycarboxylate superplasticizer, thereby achieving a higher water reduction rate. As an alkaline environment is formed during cement hydration, the ester groups gradually hydrolyze, and the silicone oil structure is released from the superplasticizer molecule, exerting its efficient defoaming effect in situ, effectively eliminating air bubbles in the concrete and on the concrete surface. At the same time, the introduction of the silicone oil structure changes the hydrophilic-lipophilic balance value of the superplasticizer molecule. Together with the low molecular weight side chains introduced by the low molecular weight polyether monomer, it endows it with a certain viscosity reduction ability, which helps to solve the high viscosity problem caused by the low water-cement ratio in ultra-high performance concrete (UHPC), and improves the workability and pumping performance of concrete.

[0019] Furthermore, in the preferred formulation, the unsaturated macromonomer, unsaturated micromonomer, and foam-controlling monomer, within the preferred ratio range, exhibit good synergistic effects, ensuring both the smooth progress of the polymerization reaction and the balanced performance of properties such as water reduction, viscosity reduction, and foam control. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] Example 1 (1) Add 300.00g of ethylene glycol monovinyl polyethylene glycol ether with a molecular weight of 3000, 110.00g of 4-hydroxybutylvinyl polyoxyethylene ether with a molecular weight of 1100, 3.00g of side-chain acrylate modified silicone oil with a molecular weight of 300, 0.01g of ferrous sulfate and 330.00g of water to the reactor, turn on the stirrer and temperature control device, and wait for the materials to mix evenly before starting to add acrylic acid aqueous solution (of which, 44.00g of acrylic acid) dropwise. The following ingredients were added: 30.00g water, 30.00g hydrogen peroxide solution (containing 3.50g 27.5% hydrogen peroxide and 30.00g water), 2.00g mercaptopropionic acid solution (containing 30.00g mercaptopropionic acid and 30.00g water), and 0.5g ascorbic acid solution (containing 30.00g water). The initial reaction temperature was 13℃, the dropping time was 1.0h, the material temperature was controlled ≤30℃ during the dropping process, and the temperature was kept warm for 1h after the dropping was completed to obtain the copolymer product. (2) Add 7g of 32% sodium hydroxide aqueous solution to the copolymer product obtained in step (1) to obtain the special polycarboxylic acid high-performance water-reducing agent KZJ-1 for wind power tower tube segments.

[0022] Example 2 (1) Add 300.00g of ethylene glycol monovinyl polyethylene glycol ether with a molecular weight of 3000, 100.00g of polyethylene glycol monomethyl ether acrylate with a molecular weight of 1200, 4.00g of side-chain acrylate modified silicone oil with a molecular weight of 400, 0.008g of ferrous sulfate, and 310.00g of water to the reactor. Turn on the stirrer and temperature control device. After the materials are mixed evenly, start adding the acrylic acid aqueous solution (of which, 32.00g of acrylic acid...). The following ingredients were added: 3.20 g of 27.5% hydrogen peroxide and 30.00 g of water; 1.80 g of thioglycolic acid and 30.00 g of water; and 2.5 g of phytic acid and 30.00 g of water. The initial reaction temperature was 15℃, the dropping time was 1.0 h, the material temperature was controlled ≤30℃ during the dropping process, and the temperature was kept warm for 1 h after the dropping was completed to obtain the copolymer product. (2) Add 5g of 32% sodium hydroxide aqueous solution to the copolymer product obtained in step (1) to obtain the special polycarboxylic acid high-performance water-reducing agent KZJ-2 for wind power tower tube segments.

[0023] Example 3 (1) Add 200.00g of ethylene glycol monovinyl polyethylene glycol ether with a molecular weight of 3000, 150.00g of 2-methylallyl polyethylene glycol with a molecular weight of 2400, 50.00g of polyethylene glycol monomethyl ether acrylate with a molecular weight of 700, 1.00g of side-chain acrylate modified silicone oil with a molecular weight of 200, 0.012g of ferrous sulfate and 320.00g of water to the reactor, turn on the stirrer and temperature control device, and wait for the materials to be mixed evenly before starting to add acrylic acid aqueous solution dropwise. The following solutions were prepared: (38.00g acrylic acid and 30.00g water), hydrogen peroxide aqueous solution (3.60g 27.5% hydrogen peroxide and 30.00g water), mercaptoethanol aqueous solution (1.40g mercaptoethanol and 30.00g water), and sodium formaldehyde sulfoxylate aqueous solution (0.6g sodium formaldehyde sulfoxylate and 30.00g water). The initial reaction temperature was 15℃, the dropping time was 1.25h, the material temperature was controlled ≤30℃ during the dropping process, and the temperature was kept warm for 1h after the dropping was completed to obtain the copolymer product. (2) Add 6g of 32% sodium hydroxide aqueous solution to the copolymer product obtained in step (1) to obtain the special polycarboxylic acid high-performance water-reducing agent KZJ-3 for wind power tower tube segments.

[0024] Comparative Example 1 (1) Add 300.00g of ethylene glycol monovinyl polyethylene glycol ether with a molecular weight of 3000, 110.00g of 4-hydroxybutylvinyl polyoxyethylene ether with a molecular weight of 1100, 0.01g of ferrous sulfate and 330.00g of water to the reactor, turn on the stirrer and temperature control device, and wait for the materials to be mixed evenly. Then start to add acrylic acid aqueous solution (44.00g of acrylic acid and 30.00g of water), hydrogen peroxide aqueous solution (3.50g of 27.5% hydrogen peroxide and 30.00g of water), mercaptopropionic acid aqueous solution (2.00g of mercaptopropionic acid and 30.00g of water), and ascorbic acid aqueous solution (0.5g of ascorbic acid and 30.00g of water). The initial reaction temperature is 13℃, the dripping time is 1.0h, the material temperature is controlled to be ≤30℃ during the dripping process, and the temperature is kept warm for 1h after the dripping is completed to obtain the copolymer product. (2) Add 7g of 32% sodium hydroxide aqueous solution to the copolymer obtained in step (1) to obtain the comparative sample PCE-1.

[0025] Comparative Example 2 (1) Add 300.00g of ethylene glycol monovinyl polyethylene glycol ether with a molecular weight of 3000, 3.00g of side-chain acrylate modified silicone oil with a molecular weight of 300, 0.01g of ferrous sulfate and 330.00g of water to the reactor, turn on the stirrer and temperature control device, and wait for the materials to be mixed evenly. Then start to add acrylic acid aqueous solution (44.00g of acrylic acid and 30.00g of water), hydrogen peroxide aqueous solution (3.50g of 27.5% hydrogen peroxide and 30.00g of water), mercaptopropionic acid aqueous solution (2.00g of mercaptopropionic acid and 30.00g of water), and ascorbic acid aqueous solution (0.5g of ascorbic acid and 30.00g of water). The initial reaction temperature is 13℃, the dropping time is 1.0h, the material temperature is controlled to be ≤30℃ during the dropping process, and the temperature is kept warm for 1h after the dropping is completed to obtain the copolymer product. (2) Add 7g of 32% sodium hydroxide aqueous solution to the copolymer obtained in step (1) to obtain the comparative sample PCE-2.

[0026] Comparative Example 3 (1) Add 300.00g of ethylene glycol monovinyl polyethylene glycol ether with a molecular weight of 3000, 0.01g of ferrous sulfate and 330.00g of water to the reactor, turn on the stirrer and temperature control device, and wait for the materials to be mixed evenly. Then start to add acrylic acid aqueous solution (44.00g of acrylic acid and 30.00g of water), hydrogen peroxide aqueous solution (3.50g of 27.5% hydrogen peroxide and 30.00g of water), mercaptopropionic acid aqueous solution (2.00g of mercaptopropionic acid and 30.00g of water) and ascorbic acid aqueous solution (0.5g of ascorbic acid and 30.00g of water). The initial reaction temperature is 13℃, the dropping time is 1.0h, the material temperature is controlled to be ≤30℃ during the dropping process, and the temperature is kept warm for 1h after the dropping is completed to obtain the copolymer product. (2) Add 7g of 32% sodium hydroxide aqueous solution to the copolymer obtained in step (1) to obtain the comparative sample PCE-3.

[0027] Performance testing: 1. Concrete performance testing According to the concrete mix proportions of wind turbine tower segments (as shown in Table 1), concrete performance tests were conducted on the special polycarboxylate high-performance water-reducing agents for wind turbine tower segments prepared in Examples 1 to 3 and the comparative samples prepared in Comparative Examples 1 to 3. By adjusting the admixture dosage, the initial flowability of the concrete was kept within the range of 700±20mm. The test results are shown in Table 2. Table 1 Concrete Mix Proportions Table 2 Test Results As shown in Table 2: The comparison results between KZJ-1 and PCE-1 show that PCE-1 without side-chain acrylate-modified silicone oil has lower demolding strength and 28-day compressive strength, and a significantly higher number of apparent bubbles. This is mainly because it lacks the defoaming effect provided by the hydrolysis of side-chain acrylate-modified silicone oil. Meanwhile, PCE-1 has a slightly higher folded solids content and T... 500 The process takes a little longer, mainly because the introduction of side-chain acrylate-modified silicone oil not only enhances the foam control effect, but also improves the water reduction and viscosity reduction effect to a certain extent due to the steric hindrance it provides and the effect of changing the molecular HLB.

[0028] The comparison results between KZJ-1 and PCE-2 show that PCE-2 without 4-hydroxybutylvinyl polyoxyethylene ether (1100 molecular weight) has significantly worse viscosity reduction and water reduction effects. This is mainly because the lower molecular weight 4-hydroxybutylvinyl polyoxyethylene ether can play a better role in reducing viscosity. At the same time, removing only 4-hydroxybutylvinyl polyoxyethylene ether results in a large change in the molecular weight acid-ether ratio, which also has a significant impact on the water reduction effect of the product. However, the compressive strength and apparent number of bubbles of PCE-2 are better than those of PCE-1. This is mainly because PCE-2 still has the defoaming effect provided by the hydrolysis of side-chain acrylate modified silicone oil. However, compared with KZJ-1, PCE-2 still has slightly worse compressive strength and apparent number of bubbles. This is mainly because when the concrete viscosity is high, bubbles are more difficult to eliminate.

[0029] The comparison results between KZJ-1 and PCE-3 show that when both the side-chain acrylate-modified silicone oil and the 4-hydroxybutylvinyl polyoxyethylene ether with a molecular weight of 1100 are removed, the water-reducing, viscosity-reducing, strengthening, and foam-controlling effects of PCE-3 are significantly worse.

[0030] The product synthesized according to the technical solution of the present invention has a high water reduction rate and good effects in reducing viscosity, strengthening and controlling foam.

[0031] Although this document frequently uses terms such as unsaturated macromonomers, unsaturated micromonomers, and monomers that enhance foam control, the possibility of using other terms is not excluded. These terms are used merely for the convenience of describing and explaining the essence of this invention; interpreting them as any additional limitation would contradict the spirit of this invention.

[0032] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A high-performance polycarboxylate superplasticizer for wind turbine tower segments, characterized in that: It is polymerized from unsaturated monomers under the action of an initiator and a molecular weight regulator; Among them, the unsaturated monomers include unsaturated macromonomers, unsaturated micromonomers, and monomers for enhancing the foam control function; The monomer for enhancing the foam control function is an unsaturated carboxylic acid ester silicone oil; the unsaturated micromonomer is an unsaturated carboxylic acid and / or an unsaturated carboxylic anhydride.

2. The polycarboxylate superplasticizer for wind turbine tower segments according to claim 1, characterized in that: The mass ratio of the unsaturated macromonomer, the unsaturated micromonomer, and the monomer for enhancing the foam control function is 200:(5 - 60):a, where 0 < a ≤ 5; the dosage of the initiator is 0.5% - 6.0% of the total mass of the unsaturated monomers; the dosage of the molecular weight regulator is 0.2% - 3.0% of the total mass of the unsaturated monomers.

3. The polycarboxylate superplasticizer for wind turbine tower segments according to claim 1, characterized in that: The molecular weight of the unsaturated carboxylic acid ester silicone oil is 200 - 600, and it is selected from at least one of mono - terminal acrylate silicone oil, side - chain acrylate - modified silicone oil, mono - terminal methacrylate silicone oil, and side - chain methacrylate - modified silicone oil.

4. The polycarboxylate superplasticizer for wind turbine tower segments according to claim 1, characterized in that: The molecular weight of the unsaturated macromonomer is 400 - 6000, and it is selected from at least one of 3 - methyl - 3 - butene - 1 - polyethylene glycol, 2 - methylallyl polyethylene glycol, ethylene glycol mono - vinyl polyethylene glycol ether, 4 - hydroxybutyl vinyl polyoxyethylene ether, polyethylene glycol monomethyl ether acrylate, and polyethylene glycol monomethyl ether methacrylate. The unsaturated carboxylic acid and / or unsaturated carboxylic anhydride is at least one of acrylic acid, methacrylic acid, and maleic anhydride.

5. The polycarboxylate superplasticizer for wind turbine tower segments according to claim 4, characterized in that: The unsaturated macromonomer contains a low - molecular - weight polyether monomer with a mass fraction greater than 10%. The molecular weight of the low - molecular - weight polyether monomer is 400 - 1500, and it is selected from at least one of 3 - methyl - 3 - butene - 1 - polyethylene glycol, 2 - methylallyl polyethylene glycol, ethylene glycol mono - vinyl polyethylene glycol ether, 4 - hydroxybutyl vinyl polyoxyethylene ether, polyethylene glycol monomethyl ether acrylate, and polyethylene glycol monomethyl ether methacrylate.

6. The polycarboxylate superplasticizer for wind turbine tower segments according to claim 1, characterized in that: The initiator is selected from at least one of the combination of hydrogen peroxide and ascorbic acid, the combination of hydrogen peroxide and phytic acid, the combination of hydrogen peroxide and sodium formaldehyde sulfoxylate, the combination of hydrogen peroxide and BRUGGOLITE E51, the combination of hydrogen peroxide, ascorbic acid and ferrous sulfate, the combination of hydrogen peroxide, phytic acid and ferrous sulfate, the combination of hydrogen peroxide, sodium formaldehyde sulfoxylate and ferrous sulfate, the combination of hydrogen peroxide, BRUGGOLITE E51 and ferrous sulfate, and ammonium persulfate.

7. The polycarboxylate superplasticizer for wind turbine tower segments according to claim 1, characterized in that: The molecular weight regulator is selected from at least one of thioglycolic acid, mercaptoethanol, thiopropionic acid, sulfonated thiopropionic acid, and sodium hypophosphite.

8. The polycarboxylate superplasticizer for wind turbine tower segments according to claim 1, characterized in that: The process of the polymerization reaction includes: dropping an aqueous solution of the initiator, an aqueous solution of the molecular weight regulator, and an aqueous solution of the unsaturated carboxylic acid and / or unsaturated carboxylic anhydride into the reaction system within 0.5 - 3 hours. The reaction temperature is 5 - 90°C, and after dropping, it is kept warm for 0.5 - 1 hour.

9. A method for preparing a high-performance polycarboxylate superplasticizer for wind turbine tower segments according to any one of claims 1-8, characterized in that, It includes the following steps: Mix the unsaturated macromonomer, the monomer for enhancing the foam control function, and water to obtain a base material; Drop the unsaturated micromonomer, the initiator, and the molecular weight regulator into the base material for polymerization reaction to obtain a copolymer product; Add alkali to the copolymer to adjust the pH value to 5-7, or collect the product directly without adding alkali, to obtain the special polycarboxylate high-performance water-reducing agent for wind turbine tower tube segments.

10. The preparation method according to claim 9, characterized in that: The conditions for the polymerization reaction include: a dropping time of 0.5 to 3 hours, an initial reaction temperature of 10 to 90°C, a material temperature of 10 to 90°C during the dropping process, and a holding time of 0.5 to 1 hour after the dropping is completed.

Images