Non-air-entraining antifreeze agent and preparation method and application thereof

Abstract

The invention relates to the technical field of building material admixtures, and particularly discloses a non-air-entraining type anti-freezing agent, a preparation method thereof and application of the non-air-entraining type anti-freezing agent in a cement-based material. The polymer structure of the non-air-entraining type anti-freezing agent is an X-Y-X type copolymer, X is a polyvinyl alcohol (PVA) block, and Y is a polyethylene glycol (PEG) block; the specific structure of the compound can be shown in the following structural formula. In the structural formula, R is-O-or-CH2O-; r1 and R2 represent terminal groups of the copolymer and are both considered as-H or-OH; n represents the number of ethylene glycol repetitive units in the central PEG block, and n is equal to 100-1000; the invention aims at solving the technical defects that the existing cement-based material antifreeze agent mainly depends on introduction of a large number of pores to improve the freezing resistance but obviously sacrifices the mechanical strength, or introduction of harmful ions such as chlorides and the like causes corrosion of steel bars.

Description

Technical Field

[0001] This application belongs to the field of building material admixtures technology, and more specifically, it relates to a non-air-entraining antifreeze agent, its preparation method and application. Background Technology

[0002] Cement-based materials are the most widely used building materials worldwide and a significant contributor to national economic growth. Under the national strategy of building a strong transportation network, a large amount of infrastructure, including bridges, tunnels, and highways, is being planned and constructed in my country's central and western regions. According to relevant design standards, the frost resistance of building materials for cold regions must be considered. Buildings in cold regions undergo freeze-thaw cycles in winter. Moisture contained in cement-based materials crystallizes in the pores, generating crystallization pressure, water pressure, and osmotic pressure, accelerating the formation and propagation of microcracks. This reduces the material's mechanical properties, accelerates the erosion by moisture and harmful ions, and shortens its lifespan.

[0003] Antifreeze agents for cement-based materials are additives that prevent damage to cement-based materials under freeze-thaw cycles. Commonly used antifreeze agents are gas-introducing surfactants, also known as air-entraining agents. After the cement-based material cures, the resulting air pores buffer the pressure of the crystallization process. However, introducing nearly 10% air volume can significantly reduce the mechanical properties of the cement-based material, and the distribution and size of the pores are uncontrollable, leading to other durability problems. Other antifreeze agents include chlorides and nitrates, but these present the critical durability issue of steel reinforcement corrosion. Recent patent reports also mention the use of nanomaterials to enhance the density of cement-based materials and the introduction of superabsorbent particles and fibers; however, none of these methods improve the freeze-thaw resistance of cement-based materials by inhibiting ice growth.

[0004] Developing a non-aeration porous material to inhibit ice growth is of great significance for ensuring the durability and safety of infrastructure in cold regions. Summary of the Invention

[0005] This application provides a non-air-entraining antifreeze agent, its preparation method, and its application. The antifreeze agent of this application can stably exist in the pores of cement-based materials after hardening without introducing closed pores. Its functional groups can effectively inhibit the formation and growth of ice crystals in micro- and nano-pores, thus effectively improving the durability and safety of infrastructure in cold regions. Furthermore, this non-air-entraining antifreeze agent has broad compatibility with sand and gravel aggregates and cement, and can improve the fluidity and viscosity of cement-based materials. It can be used after concrete mixing and hardening, and has broad application prospects in engineering projects in cold regions.

[0006] In a first aspect, this application provides a non-air-entraining antifreeze, employing the following technical solution: A non-air-entraining antifreeze agent, wherein the polymer structure of the non-air-entraining antifreeze agent is an XYX type copolymer, where X is a polyvinyl alcohol (PVA) block and Y is a polyethylene glycol (PEG) block; its specific structure can be represented by the following structural formula: .

[0007] In the structural formula, R is -O- or -CH2O-; R1 and R2 represent the terminal groups of the copolymer, both of which are considered as -H or -OH; n represents the number of ethylene glycol repeating units in the central PEG block, n = 100 - 1000; m represents the number of ethylene alcohol repeating units in each PVA block at both ends, m = 100 - 500.

[0008] By adopting the above technical solutions, the antifreeze polymer of this application has a long-chain polymer structure containing a multi-chain block structure and good water solubility; moreover, the polymer exhibits good stability after over-blending modification by adjusting the linking ratio between chain segments; the polymer can not only directly inhibit the formation and growth of ice, but the long-chain structure formed can also exist in the pore structure of the hydration products of cement-based materials, preventing the development of ice crystals and the resulting damage at low temperatures; moreover, the polymer of this application has broad adaptability to sand and gravel aggregates and cement, and can improve the fluidity and viscosity of cement-based materials, and can be used after concrete mixing and hardening, showing broad application prospects in cold region engineering.

[0009] Furthermore, the weight-average molecular weight of the polymer in the non-air-entraining antifreeze is controlled between 15,000 and 80,000. If the molecular weight of the polymer in the non-air-entraining antifreeze is too high, it will lead to gelation; if it is too low, it will not be able to produce an anti-icing effect in the pores of the hardened cement paste.

[0010] Furthermore, the non-air-entraining antifreeze is obtained by block copolymerization nucleophilic substitution reaction comprising hydrolyzed X-chain reactant A and chlorinated Y-chain reactant C; wherein, the hydrolyzed X-chain reactant A is prepared by alcoholysis of polyvinyl acetate, a free radical polymerization product, and sodium alkoxide reaction of strong base; and the chlorinated Y-chain reactant C is prepared by converting the terminal hydroxyl groups of polyvinyl alcohol into electrophilic leaving groups.

[0011] By adopting the above-mentioned technical protection scheme, the hydrolyzed X-chain reactant A, i.e., sodium PVA alkoxide, can carry out a nucleophilic substitution reaction on the chlorinated Y-chain reactant C, i.e., activated PEG, to achieve terminal coupling and form an XYX triblock copolymer.

[0012] Secondly, this application provides a method for preparing a non-air-entraining antifreeze, which adopts the following technical solution: A method for preparing a non-air-entraining antifreeze includes the following steps: (1) Hydrolysis of X block reactant A: After reactant A is dissolved by heating under argon protection, hydroxide E-ethanol solution is added and heated to boiling. The mixture is refluxed for 3-5 hours. As the reaction proceeds, the product continues to precipitate from the ethanol solution. After extraction and drying, product B is obtained, which is the hydrolyzed X chain reactant A. (2) Chlorination of Y-block reactant C: Dissolve reactant C in toluene, heat to boiling under argon protection, reflux for 1-3 hours using a water separator, separate the reaction liquid, add catalyst F and dropwise add sulfone chloride solution, react at 100-110℃ for 5-10 hours, and then precipitate to obtain product D, i.e. chlorinated Y-chain reactant C. (3) Block copolymerization nucleophilic substitution reaction: a) Dissolve product B in anhydrous dimethyl sulfoxide. After complete dissolution, add excess sodium hydride in batches under argon protection and stir the reaction at 45℃-65℃ until no more hydrogen is produced. b) Heat the solution from step a) to 60-80°C, and slowly add the dimethyl sulfoxide solution of product D dropwise to the reaction system under argon protection and vigorous stirring; after the addition is complete, continue the reaction at 60-80°C for 24-48 hours; after the reaction is complete, cool and precipitate, centrifuge, extract and dry to obtain the final product.

[0013] Furthermore, hydroxide E includes at least one of potassium hydroxide, sodium hydroxide, and lithium hydroxide.

[0014] Furthermore, catalyst F includes at least one of pyridine, 1,2-bis(4-pyridyl)ethylene, butyric acid, and 2,4,6-pyridinetricarboxyl chloride.

[0015] Furthermore, in the hydrolysis step of the side-chain reactant A, the molar ratio of the functional groups of reactant A to hydroxide E is 1:(1.2~1.5). In the hydroxide E-ethanol solution, ethanol is the solvent and is in excess.

[0016] Furthermore, in the chlorination step of the Y-segment reactant C, the molar ratio of sulfone chloride solution to the separated reaction solution is (1~4):1. Specifically, this molar ratio refers to the molar ratio of the functional groups reacting in the sulfone chloride solution to those in the separated solution.

[0017] Furthermore, in the block copolymer nucleophilic substitution reaction step, product B and product D are mixed in a chain molar ratio of (2.2~2.5):1.

[0018] Thirdly, this application provides an application of a non-air-entraining antifreeze agent, employing the following technical solution: Application of a non-air-entraining antifreeze agent, wherein the non-air-entraining antifreeze agent is used as a concrete antifreeze agent, and the dosage of the antifreeze agent is 0.01% to 1.0% of the total cementitious material mass, preferably 0.02% to 0.6%.

[0019] Furthermore, the antifreeze agent of this application can be used in combination with commercially available water-reducing agents, such as lignosulfonate water-reducing agents, naphthalene sulfonate water-reducing agents, polycarboxylate water-reducing agents, etc., and can also be used after adding retarders, early strength agents, expansion agents, thickeners, shrinkage reducers and defoamers.

[0020] In summary, this application has the following beneficial effects: (1) Non-entraining mechanism: The copolymer molecules can exist stably in the pore solution of hardened cementitious materials without introducing macroscopic pores. The high-density hydroxyl functional groups on its PVA blocks can be adsorbed on the surface of ice crystals through hydrogen bonding, effectively inhibiting the nucleation and growth of ice crystals in the micro-nano pores of cementitious materials, fundamentally resisting freeze-thaw damage, inhibiting freeze-thaw damage, reducing maintenance costs while improving the durability of cementitious materials; and has the potential to enhance salt scale resistance and salt corrosion resistance.

[0021] (2) Mechanical property retention: Due to its non-air-entraining properties, this antifreeze agent can impart excellent antifreeze durability to the material while avoiding a significant decrease in mechanical strength caused by the introduction of a large number of pores.

[0022] (3) No harmful ions: The polymer does not contain corrosive components such as chloride ions, so there is no risk of rust on the steel bars.

[0023] (4) Improved workability: The copolymer also improves the fluidity of fresh cementitious materials and has good construction adaptability.

[0024] (5) The antifreeze production process of this application is green and simple, with high production efficiency, low cost, and easy to achieve large-scale production. Detailed Implementation

[0025] The present application will be further described in detail below with reference to the embodiments.

[0026] This application provides a non-air-entraining antifreeze and its preparation method. The preparation process of the antifreeze includes the following steps: (1) Hydrolysis of X block reactant A: After reactant A is dissolved by heating under argon protection, hydroxide E-ethanol solution is added and heated to boiling. The mixture is refluxed for 3-5 hours. As the reaction proceeds, the product continues to precipitate from the ethanol solution. After extraction and drying, product B is obtained, which is the hydrolyzed X chain reactant A. The functional group molar ratio of reactant A to hydroxide E is 1:(1.2~1.5). In the hydroxide E-ethanol solution, ethanol is the solvent and is in excess.

[0027] (2) Chlorination of Y-block reactant C: Dissolve reactant C in toluene at a dosage of (60-80g) / 500ml, heat to boiling under argon protection, reflux for 1-3 hours using a water separator, separate the reaction liquid, add catalyst F and dropwise add sulfone chloride solution, react at 100-110℃ for 5-10 hours, and then precipitate to obtain product D, i.e. chlorinated Y-chain reactant C; wherein, the molar ratio of sulfone chloride solution to the separated reaction liquid is (1~4):1.

[0028] (3) Block copolymerization nucleophilic substitution reaction: a) Dissolve product B in anhydrous dimethyl sulfoxide at a dosage of (2-5g) / 400ml. After complete dissolution, add excess sodium hydride in batches under argon protection and stir the reaction at 45℃-65℃ until no more hydrogen is produced. b) Heat the solution from step a) to 60-80℃, and under argon protection and vigorous stirring, slowly add a dimethyl sulfoxide solution of product D dropwise to the reaction system; after the addition is complete, continue the reaction at 60-80℃ for 24-48 hours; after the reaction is complete, cool and precipitate, centrifuge, extract and dry to obtain the final product. The chain molar ratio of product B to product D is (2.2~2.5):1; additionally, product D is dissolved in 50-100 ml of a small amount of anhydrous DMSO to obtain a dimethyl sulfoxide solution of product D.

[0029] Furthermore, in the above preparation process, PEG (reactant C) Mn: 10,000 ~ 35,000 g / mol; PVAc (free radical polymerization product of reactant A) Mn: 10,000 ~ 60,000 g / mol.

[0030] Non-air-entrained antifreeze is composed of polymer and water, with the polymer accounting for 30-60% of the water-reducing agent by mass.

[0031] The polymer structure of the aforementioned non-air-entraining antifreeze is an XYX type copolymer, where X is a polyvinyl alcohol (PVA) block and Y is a polyethylene glycol (PEG) block; its specific structure can be represented by the following structural formula: .

[0032] In the structural formula, R is -O- or -CH2O-; R1 and R2 represent the terminal groups of the copolymer, both considered as -H or -OH; n represents the number of ethylene glycol repeating units in the central PEG block, n = 100 - 1000; m represents the number of vinyl alcohol repeating units in each PVA block at both ends, m = 100 - 500. The weight-average molecular weight of the polymer in the non-gas-entraining antifreeze is controlled between 15,000 and 80,000.

[0033] The following explanation is provided through specific examples.

[0034] Example 1 This application provides a non-air-entraining antifreeze and its preparation method. The preparation process of the antifreeze includes the following steps: (1) Hydrolysis of X-block reactant A: 35.0 g of reactant A was dissolved in an appropriate amount of ethanol and heated under argon protection to obtain a PVAc solution. Separately, 29.6 g of potassium hydroxide (KOH) was dissolved in excess ethanol, and the resulting solution was added to the PVAc solution. The mixture was heated to boiling and refluxed for 4 hours. After the reaction was complete, the solid was collected by cooling and filtration. The product was extracted with ethanol in a Soxhlet extractor for 24 h and then dried to constant weight in a vacuum drying oven at 60 °C to obtain hydrolysis product B.

[0035] (2) Chlorination of Y-block reactant C: Dissolve 70 g of reactant C in 500 mL of toluene and azeotropically remove water for 2 hours. Take 100 mL of this solution and add 3 mL of toluene solution containing 0.00007 mol of butylpicoamide, then slowly add 0.25 mL of sulfone chloride. React at 110 °C for 8 hours. After the reaction is complete, cool the solution and add it dropwise to anhydrous diethyl ether at 0 °C to precipitate. Filter to collect the solid, wash several times with diethyl ether, and then vacuum dry to obtain chloride reactant D.

[0036] (3) Block copolymerization: a) Dissolve 19.8 g of product B in approximately 800 mL of anhydrous DMSO, and heat and stir until completely dissolved. After cooling, add excess sodium hydride (NaH) in batches under argon protection. Stir the reaction at 55°C until no more hydrogen gas is produced.

[0037] b) Simultaneously, take 10.0 g of product D, dissolve it in 80 mL of anhydrous DMSO, and place it in a constant pressure dropping funnel.

[0038] c) Heat the solution from step a) to 70°C. Under argon protection and vigorous stirring, very slowly add the DMSO solution of product D from step b) to the reaction system over 5 hours. After the addition is complete, continue the reaction at 70°C for 36 hours. After the reaction is complete, cool and perform subsequent precipitation, centrifugation, extraction, and drying to obtain the final product, the antifreeze.

[0039] With a target molecular weight of 60,000 g / mol and a block mass ratio of PEG:PVA ≈ 1:1.5 as the target, the selected molecular weights of polyethylene glycol (Mn) are approximately 20,000 g / mol and polyvinyl acetate (Mn) are approximately 35,000 g / mol.

[0040] Example 2 This application provides a non-air-entraining antifreeze and its preparation method. The preparation process of the antifreeze includes the following steps: (1) Hydrolysis of X-block reactant A: 52.0 g of reactant A was dissolved in an appropriate amount of ethanol and heated under argon protection to obtain a PVAc solution. Separately, 46.8 g of potassium hydroxide (KOH) was dissolved in excess ethanol, and the resulting solution was added to the PVAc solution. The mixture was heated to boiling and refluxed for 5 hours. After the reaction was complete, the solid was collected by cooling and filtration. The product was extracted with ethanol in a Soxhlet extractor for 24 h and then dried to constant weight in a vacuum drying oven at 60 °C to obtain hydrolysis product B.

[0041] (2) Chlorination of Y-block reactant C: Dissolve 70 g of reactant C in 500 mL of toluene and azeotropically remove water for 2 hours. Take 100 mL of this solution and add 3 mL of toluene solution containing 0.000032 mol of butylpicoamide, then slowly add 0.17 mL of sulfone chloride. React at 110 °C for 10 hours. After the reaction is complete, cool the solution and add it dropwise to anhydrous diethyl ether at 0 °C to precipitate. Filter to collect the solid, wash several times with diethyl ether, and then vacuum dry to obtain chloride reactant D.

[0042] (3) Block copolymerization a) Dissolve 18.5 g of product B in approximately 900 mL of anhydrous DMSO, and heat and stir until completely dissolved. After cooling, add excess sodium hydride (NaH) in batches under argon protection. Stir the reaction at 60 °C until no more hydrogen gas is produced.

[0043] b) Simultaneously, take 10.5 g of product D, dissolve it in 100 mL of anhydrous DMSO, and place it in a constant pressure dropping funnel.

[0044] c) Heat the solution from step a) to 75°C. Under argon protection and vigorous stirring, very slowly add the DMSO solution of product D from step b) to the reaction system over 7 hours. After the addition is complete, continue the reaction at 75°C for 48 hours. After the reaction is complete, cool and perform subsequent precipitation, centrifugation, extraction, and drying to obtain the final product, the antifreeze.

[0045] With a target molecular weight of 80,000 g / mol and a block mass ratio of PEG:PVA ≈ 1:2 as the target, the selected molecular weights of polyethylene glycol (Mn) are approximately 35,000 g / mol and polyvinyl acetate (Mn) are approximately 52,000 g / mol.

[0046] Application examples The application examples of this application provide the application of non-air-entraining antifreeze agents in the embodiments. Specifically, the non-air-entraining antifreeze agents in the embodiments are used as concrete antifreeze agents, and the dosage of the antifreeze agent is 0.01% to 1.0% of the total cementitious material mass.

[0047] The following explanation is provided through specific examples.

[0048] Application Example 1 In this application example, the product prepared in Example 1 above is used as the antifreeze agent. The target molecular weight is 60,000 g / mol, and the block mass ratio of PEG:PVA is approximately 1:1.5. The selected molecular weights are polyethylene glycol (Mn) ≈ 20,000 g / mol and polyvinyl acetate (Mn) ≈ 35,000 g / mol. Its dosage in the pre-application concrete is 0.02% (percentage of the cementitious material).

[0049] The water-cement ratio of the concrete specimens was set at 0.5. Concrete specimens with a strength of C30 were prepared using 350 kg of cement, 1075 kg of aggregate, 777 kg of sand, and 175 kg of tap water.

[0050] Application Example 2 The similarities between this application example and Application Example 1 will not be repeated here; only the differences from Application Example 1 will be described. The difference between this application example and Application Example 1 is that the dosage of the antifreeze agent in the pre-application concrete is 0.06% (as a percentage of the cementitious materials).

[0051] Application Example 3 The similarities between this application example and Application Example 1 will not be repeated here; only the differences between them will be described. The difference between this application example and Application Example 1 is that the dosage of the antifreeze agent in the pre-application concrete is 0.25% (as a percentage of the cementitious materials).

[0052] Application Example 4 The similarities between this application example and Application Example 1 will not be repeated here; only the differences from Application Example 1 will be described. The difference between this application example and Application Example 1 is that the dosage of the antifreeze agent in the pre-application concrete is 1.0% (as a percentage of the cementitious materials).

[0053] Application Example 5 The similarities between this application example and Application Example 1 will not be repeated here; only the differences from Application Example 1 will be described. The preparation product provided in Preparation Example 2 above is used as the antifreeze.

[0054] Comparative Example Comparative Example 1 The difference between this comparative example and application example 1 is that the commercially available AEA-1 type rosin-based air-entraining agent is used as an antifreeze agent, and the dosage in the concrete mixing stage is 0.02% (as a percentage of the cementitious materials).

[0055] Comparative Example 2 The difference between this comparative example and application example 1 is that, with a total additive content of 0.02%, reagents B and D were added at a mass ratio of 1:1.5 without causing them to undergo block copolymerization.

[0056] Performance testing Performance tests were conducted on the concrete prepared according to the corresponding use cases and comparative examples, with a blank control group without antifreeze added, as follows: The air content was determined according to national standard GB / T 50080-2002; freeze-thaw tests were conducted according to national standard GB / T 50082-2009. After standard curing for 28 days, the mass loss of specimens subjected to more than 300 freeze-thaw cycles was measured, and the air bubble spacing parameter was also measured. The test results are shown in Tables 1 and 2.

[0057] Table 1. Test results of gas content and hardened bubble spacing for each application example and comparative example. Table 2 Results of dynamic elasticity test after freeze-thaw test As can be seen from the experimental data in Table 1, when the synthetic sample is within the production range of 0.06%, it does not introduce a large number of air bubbles into the hardened cement-based material. The air-entraining agent in the comparative sample has an air content of 7.8% and 6.8% in the fresh and hardened states, respectively, and contains air bubbles with a spacing of less than 250 mm. The air content of the sample with the added novel antifreeze agent is less than that of the air-entraining agent, and it also shows a much larger air bubble spacing parameter than the sample with the added air-entraining agent. This indicates that the novel antifreeze agent does not inhibit the generation of freeze-thaw damage by introducing a pore system.

[0058] Table 2 shows the mechanical integrity of samples after 300 freeze-thaw cycles, observed by changes in relative modulus of elasticity. A relative modulus of elasticity of 60% is the damage threshold; values ​​below this threshold indicate freeze-thaw failure. The baseline sample completely failed after 100 freeze-thaw cycles. Observation showed that adding 0.02% of the novel antifreeze agent resulted in failure after 200 freeze-thaw cycles. Samples with a dosage greater than 0.02%, as well as those with added air-entraining agents, maintained a modulus of elasticity above 60% after more than 200 freeze-thaw cycles, demonstrating the effectiveness of the novel antifreeze agent.

[0059] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A non-air-entraining antifreeze, characterized in that, The non-air-entraining antifreeze has a polymer structure of XYX type copolymer, where X is a polyvinyl alcohol (PVA) block and Y is a polyethylene glycol (PEG) block; its specific structure can be represented by the following structural formula: 。 In the structural formula, R is -O- or -CH2O-; R1 and R2 are both -H or -OH; n represents the number of ethylene glycol repeating units in the central PEG block, n = 100 - 1000; m represents the number of vinyl alcohol repeating units in each PVA block at both ends, m = 100 - 500.

2. The non-air-entraining antifreeze according to claim 1, characterized in that, The weight-average molecular weight of the polymer in the non-air-entraining antifreeze is controlled between 15,000 and 80,000.

3. The non-air-entraining antifreeze according to claim 1, characterized in that, The non-air-entraining antifreeze is obtained by block copolymerization nucleophilic substitution reaction comprising hydrolyzed X-chain reactant A and chlorinated Y-chain reactant C; wherein, the hydrolyzed X-chain reactant A is prepared by alcoholysis of polyvinyl acetate, a free radical polymerization product, and sodium alkoxide reaction of strong base; and the chlorinated Y-chain reactant C is prepared by converting the terminal hydroxyl groups of polyvinyl alcohol into electrophilic leaving groups.

4. A method for preparing a non-air-entraining antifreeze as described in any one of claims 1-3, characterized in that, Includes the following steps: (1) Hydrolysis of X block reactant A: After reactant A is dissolved by heating under argon protection, hydroxide E-ethanol solution is added and heated to boiling. The mixture is refluxed for 3-5 hours. As the reaction proceeds, the product continues to precipitate from the ethanol solution. After extraction and drying, product B is obtained, which is the hydrolyzed X chain reactant A. (2) Chlorination of Y-block reactant C: Dissolve reactant C in toluene, heat to boiling under argon protection, reflux for 1-3 hours using a water separator, separate the reaction liquid, add catalyst F and dropwise add sulfone chloride solution, react at 100-110℃ for 5-10 hours, and then precipitate to obtain product D, i.e. chlorinated Y-chain reactant C. (3) Block copolymerization nucleophilic substitution reaction: a) Dissolve product B in anhydrous dimethyl sulfoxide. After complete dissolution, add excess sodium hydride in batches under argon protection and stir the reaction at 45℃-65℃ until no more hydrogen is produced. b) Heat the solution from step a) to 60-80°C, and slowly add the dimethyl sulfoxide solution of product D dropwise to the reaction system under argon protection and vigorous stirring; after the addition is complete, continue the reaction at 60-80°C for 24-48 hours; after the reaction is complete, cool and precipitate, centrifuge, extract and dry to obtain the final product.

5. The method for preparing a non-air-entraining antifreeze according to claim 4, characterized in that, Hydroxide E includes at least one of potassium hydroxide, sodium hydroxide, and lithium hydroxide.

6. The method for preparing a non-air-entraining antifreeze according to claim 4, characterized in that, Catalyst F includes at least one of pyridine, 1,2-bis(4-pyridyl)ethylene, butyric acid, and 2,4,6-pyridinetricarboxyl chloride.

7. The method for preparing a non-air-entraining antifreeze according to claim 4, characterized in that, In the step of hydrolyzing reactant A of block X, the molar ratio of functional groups of reactant A to hydroxide E is 1:(1.2~1.5).

8. The method for preparing a non-air-entraining antifreeze according to claim 4, characterized in that, In the chlorination step of the Y-segment reactant C, the molar ratio of sulfone chloride solution to the separated reaction solution is (1~4):

1.

9. The method for preparing a non-air-entraining antifreeze according to claim 4, characterized in that, In the block copolymer nucleophilic substitution reaction step, product B and product D are mixed in a chain molar ratio of (2.2~2.5):

1.

10. The application of a non-air-entraining antifreeze as described in any one of claims 1-3, characterized in that, The non-air-entraining antifreeze agent is used as an antifreeze agent for concrete, and the dosage of the antifreeze agent is 0.01% to 1.0% of the total cementitious material mass.

Images