Anticorrosive liquid polycarboxylate superplasticizer as well as preparation method and application thereof

Abstract

The invention discloses an anti-corrosion liquid polycarboxylic acid water reducing agent as well as a preparation method and application thereof, and belongs to the technical field of water reducing agents. The preparation method comprises the following steps: carrying out a free radical polymerization reaction on an imidazolyl ionic liquid monomer with a vinyl-terminated long-chain structure, an unsaturated carboxylic acid small monomer, an initiator and a chain transfer agent in a benzene solvent at 65-85 DEG C for 3-5 hours, then cooling to 25 DEG C or below, and layering to obtain the pure anti-corrosion liquid polycarboxylate superplasticizer, the anti-bacterial property is achieved, and the problem that mildew is prone to occurring when the anti-bacterial agent is compounded with a retarder for use in summer is solved; the liquid polycarboxylate superplasticizer with the solid content of 100% can be directly obtained after the liquid polycarboxylate superplasticizer is mutually soluble with the benzene-series solvent at a high temperature, two phases are separated when the liquid polycarboxylate superplasticizer is cooled to the room temperature and the benzene-series solvent on the upper layer is separated, so that the transportation cost is greatly saved, the dissolving property is good, meanwhile, the benzene-series solvent can be recycled, the production cost is reduced, and the production efficiency is improved. And the method accords with the current green and environment-friendly production concept.

Description

Technical Field

[0001] The present invention belongs to the technical field of water reducers, and in particular relates to an anti-corrosion liquid polycarboxylate water reducer, a preparation method thereof and an application thereof. Background Art

[0002] Currently, most mainstream polycarboxylate superplasticizers on the market are water-based, with solid contents mainly ranging from 10% to 50%. Due to the low solid content and the long distance between manufacturers and commercial concrete mixing stations, construction sites, and other construction sites, transportation costs increase and storage becomes difficult. Therefore, solid polycarboxylate superplasticizers have become a research hotspot in recent years. Solid polycarboxylate superplasticizers can not only significantly reduce transportation and storage costs, but can also be widely used in grouting materials, dry-mix mortars, and other fields.

[0003] Currently, the commercially available solid polycarboxylate superplasticizer preparation process primarily relies on spray drying, but this process is labor-intensive and costly, and the addition of functional additives such as anti-caking agents can also affect product performance to a certain extent. Solid polycarboxylate superplasticizers can also be prepared through bulk polymerization, adsorption, and reactive extrusion. However, bulk polymerization has high reaction temperatures, high system viscosity, and difficulty dissipating heat, posing risks such as localized implosion and runaway reactions. The adsorption method uses highly adsorbent substances as adsorbents, which inevitably reduces the active ingredient content of the solid superplasticizer. Reactive extrusion can easily lead to uneven heat transfer and implosion.

[0004] In order to meet different construction requirements, such as construction in high-temperature environments, reducing the hydration heat of large-volume concrete, and concrete pumpability, polycarboxylate water-reducing agents are often compounded with a certain proportion of functional components such as retarding, air entraining, thickening, and water retention. Among them, sugar substances such as sodium gluconate and white sugar are more commonly used in retarders. Such substances provide a nutrient matrix for microbial reproduction. Especially in the high temperature environment of summer, microorganisms reproduce rapidly, causing the finished water-reducing agent to deteriorate and stink, and the appearance of flocculent floating matter, which clogs pipes and causes bloating of sealed containers. This not only brings economic losses, but also poses a hidden danger to the quality of concrete.

[0005] Patent publication number CN101824125A discloses a method for preparing a powdered polycarboxylate high-performance water-reducing agent. The method involves passing a polycarboxylate water-reducing agent solution through the centrifugal disk of a centrifugal spray dryer at high speed to form droplets. The solution is then dried at an inlet air temperature of 180-230°C and an outlet air temperature of 80-120°C, with an anti-sticking agent added to the air inlet duct. However, the spray drying method requires large equipment, consumes a lot of energy during the drying process, and the high temperature process adversely affects the performance of the polycarboxylate water-reducing agent.

[0006] Patent publication number CN116731264A discloses a high-purity solid polycarboxylate superplasticizer and its preparation method. Unsaturated polyether macromonomers and water-soluble acrylic monomers are continuously polymerized in a microchannel reactor to produce a high-solids polycarboxylate superplasticizer (solids content ranges from 65% to 90%). The highly concentrated aqueous solution is then continuously fed into a polymer devolatilization unit to remove small molecules such as water under reduced pressure and low temperature conditions. When the solids content reaches 95% or higher, the solid solution polycarboxylate superplasticizer can be cooled and sliced ​​to produce a flaky solid polycarboxylate superplasticizer. This method requires the removal of small molecules such as water under reduced pressure and low temperature conditions to obtain a high-purity polycarboxylate superplasticizer, which not only requires complex post-processing operations but also places high demands on the equipment.

[0007] The invention patent with publication number CN112794958A discloses an antibacterial polycarboxylate water reducer and a preparation method thereof. 4-Hydroxybenzyl halide is subjected to an azidation reaction with sodium azide to generate p-hydroxy azide, which is then reacted with a terminal alkyne compound via a 1,3-dipolar cycloaddition reaction to generate a phenolic compound containing a 1,2,3-triazole structure at the para position. This phenolic compound is then reacted with a halogenated terminal olefin compound to generate an unsaturated monomer containing 1,2,3-triazole. This is then reacted with a carbonyl-containing unsaturated acid and its derivative monomer, an unsaturated polyether macromonomer, or an unsaturated ester macromonomer in the presence of an initiator, a reducing agent, and a chain transfer agent to generate an antibacterial polycarboxylate water reducer containing 1,2,3-triazole. The unsaturated monomer of 1,2,3-triazole prepared by this method is an oil-soluble monomer. If aqueous polymerization is used to prepare the antibacterial polycarboxylic acid water-reducing agent, the monomer is difficult to polymerize well onto the molecular chain. If an organic solvent is used for polymerization, additional steps such as solvent removal and purification are required to obtain the final product.

[0008] In summary, existing high-solid content polycarboxylate water reducers (≥95%) have problems such as complex manufacturing process and high energy consumption. In addition, they are prone to mildew when used in combination with sugar retarders in summer, which will have an adverse effect on product performance. Summary of the Invention

[0009] To solve the above technical problems, the present invention provides an anti-corrosion liquid polycarboxylate water-reducing agent, a preparation method thereof, and an application thereof. The liquid polycarboxylate water-reducing agent prepared by the method has antibacterial properties, thereby avoiding the problem of mildew easily occurring when used in combination with retarders such as white sugar and sodium gluconate in summer. In addition, the polycarboxylate water-reducing agent is temperature-sensitive and is miscible with a benzene-based solvent at high temperatures. The two phases separate when cooled to room temperature, and a liquid polycarboxylate water-reducing agent with a 100% solid content can be directly obtained by simple layering. At the same time, the benzene-based solvent can be reused, which not only reduces production costs but also complies with the current green and environmentally friendly production concept.

[0010] To achieve the above object, the technical solution adopted by the present invention is as follows: An anti-corrosion liquid polycarboxylate water reducer, the anti-corrosion liquid polycarboxylate water reducer having the following structure: Wherein, R1 represents H or CH3, R2 represents one of H, COOH or COOCH3; x, y, and n are all integers, and x:y=(2~5):1, y is from 20~50, and n is from 4~18.

[0011] The present invention also provides a method for preparing the anti-corrosion liquid polycarboxylate water-reducing agent, which comprises the following steps: Step 1: Under nitrogen protection, a long-chain imidazolyl ionic liquid monomer with a vinyl end group, an unsaturated carboxylic acid small monomer, an initiator and a chain transfer agent are subjected to a free radical polymerization reaction in a benzene solvent at 65-85°C for 3-5 hours; Step 2: Cool the reaction solution to below 25°C, and the polymer and the benzene solvent will separate. The upper benzene solvent will be separated, collected and recycled, and the lower layer will be the anti-corrosion liquid polycarboxylate water reducer.

[0012] In step 1, the molar ratio of the imidazole-based ionic liquid monomer with a long chain structure having a vinyl end group, the unsaturated acid small monomer, the initiator and the chain transfer is 1: (2-5): (0.02-0.1): (0.08-0.16).

[0013] In step 1, the structural formula of the imidazolyl ionic liquid monomer having a long chain structure with a vinyl end group is: .

[0014] The preparation method of the imidazolium-based ionic liquid monomer having a long-chain structure with a vinyl end group comprises the following steps: Step S1: In an ice-water bath, sodium hydroxide, tetraethylammonium bromide, imidazole and polyethylene glycol monomethyl ether methanesulfonate are added to water, reacted at room temperature for 24 to 48 hours, and subjected to extraction, concentration and drying to obtain single-terminal imidazole-based polyethylene glycol monomethyl ether; the structural formula of the single-terminal imidazole-based polyethylene glycol monomethyl ether is: ; Step S2: Under nitrogen protection, single-end imidazole polyethylene glycol monomethyl ether and 2-bromoethyl acrylate are added to anhydrous acetonitrile, reacted at 40-50° C. for 45-50 hours, and purified to obtain a long-chain imidazole ionic liquid monomer with a vinyl end group.

[0015] The synthetic route of the imidazolyl ionic liquid monomer having a long chain structure with a vinyl end group is as follows: .

[0016] In step S1, the molar ratio of sodium hydroxide, tetraethylammonium bromide, imidazole, and polyethylene glycol monomethyl ether methanesulfonate is (100-110): (0.3-0.33): (10-11): 8.

[0017] In step S2, the molar ratio of the single-terminal imidazole polyethylene glycol monomethyl ether to 2-bromoethyl acrylate is 1:(1-1.1).

[0018] In step 1, the unsaturated carboxylic acid small monomer is at least one of acrylic acid, methacrylic acid, maleic acid or monomethyl maleate.

[0019] In step 1, the initiator is azobisisobutyronitrile, azobisisoheptanenitrile or dimethyl azobisisobutyrate; and the chain transfer agent is at least one of mercaptopropionic acid, mercaptoethanol or n-dodecyl mercaptan.

[0020] In step 1, the benzene-based solvent is at least one of benzene, toluene, and p-xylene.

[0021] The present invention also provides the use of the anti-corrosion liquid polycarboxylate water reducer as a concrete admixture, which can improve the antibacterial properties of the water reducer product, while improving the workability of concrete and increasing the compressive strength of concrete to a certain extent.

[0022] Compared with the prior art, the present invention has the following beneficial effects: (1) The antiseptic polycarboxylate water reducer prepared by the method of the present invention contains imidazole groups, which can achieve antibacterial effects by inhibiting nucleic acid synthesis, inhibiting enzyme activity, changing cell membrane permeability and interfering with protein function. It can avoid the generation of a large number of microorganisms and their metabolites after long-term storage or compounding with other functional components such as carbohydrate retarders, resulting in discoloration, mold, odor and other phenomena, leading to a decline in product performance.

[0023] (2) Based on polyethylene glycol monomethyl ether methanesulfonate, an imidazole-based ionic liquid monomer with a long chain structure is synthesized. It is then free radical polymerized with an unsaturated acid small monomer, an initiator, and a chain transfer agent to obtain a polycarboxylic acid water reducer with inherent anticorrosive and antibacterial properties. There is no need to compound a small molecule preservative, thus avoiding problems such as insolubility or precipitation caused by poor compatibility between the preservative and the polycarboxylic acid water reducer.

[0024] (3) The polycarboxylate water reducer provided by the present invention has both the temperature-sensitive properties of polyethylene glycol and the characteristics of polyionic liquids. It is miscible with benzene-based solvents at high temperatures and can achieve two-phase separation with benzene-based solvents when cooled to room temperature. During preparation, benzene-based solvents are used as reaction solvents. After the polymerization reaction is completed, a liquid polycarboxylate water reducer with a solid content of 100% can be directly obtained by simple layering. The post-processing operation is simple and convenient. Compared with the common liquid polycarboxylate water reducers (10%~50% solid content) on the market, it greatly saves transportation and storage costs. Compared with conventional solid water reducers (≥95% solid content), it has better solubility. At the same time, benzene-based solvents can be reused, which not only reduces production costs but also conforms to the current green and environmentally friendly production concept. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 Schematic diagram of the preparation method of anti-corrosion liquid polycarboxylate water-reducing agent; Figure 2 The antiseptic liquid polycarboxylate water reducer prepared in Example 1 1 H NMR spectrum. DETAILED DESCRIPTION

[0026] The present invention is described in detail below with reference to the embodiments.

[0027] Example 1

[0028] A method for preparing an anti-corrosion liquid polycarboxylate water-reducing agent comprises the following steps: (1) In an ice-water bath, polyethylene glycol monomethyl ether (degree of polymerization: 7) and triethylamine were added to diethyl ether, and stirring was started. Methanesulfonyl chloride was then added and the mixture was reacted at 25°C for 24 h. After filtration, the diethyl ether was removed by vacuum distillation. The crude product was dissolved in dichloromethane and extracted four times with deionized water to obtain polyethylene glycol monomethyl ether methanesulfonate, wherein the molar ratio of polyethylene glycol monomethyl ether, triethylamine, and methanesulfonyl chloride was 1:1:1, and the concentration of polyethylene glycol monomethyl ether in diethyl ether was 1 mol / L.

[0029] (2) Sodium hydroxide, tetraethylammonium bromide, imidazole and polyethylene glycol monomethyl ether methanesulfonate were added to water under ice-water bath conditions, reacted at 25°C for 24 hours, extracted with dichloromethane four times, and then dichloromethane was removed by rotary evaporation to obtain single-terminal imidazole-based polyethylene glycol monomethyl ether, wherein the molar ratio of sodium hydroxide, tetraethylammonium bromide, imidazole and polyethylene glycol monomethyl ether methanesulfonate was 100:0.3:10:8, and the concentration of polyethylene glycol monomethyl ether methanesulfonate in water was 1 mol / L.

[0030] (3) Under nitrogen protection, single-end imidazolyl polyethylene glycol monomethyl ether and 2-bromoethyl acrylate were added to anhydrous acetonitrile and reacted at 45°C for 48 hours. The imidazolyl ionic liquid monomer with a long-chain structure having a vinyl end group was obtained by rotary evaporation purification, wherein the molar ratio of single-end imidazolyl polyethylene glycol monomethyl ether to 2-bromoethyl acrylate was 1:1, and the concentration of single-end imidazolyl polyethylene glycol monomethyl ether in anhydrous acetonitrile was 0.75 mol / L.

[0031] (4) Under nitrogen protection, a long-chain imidazolyl ionic liquid monomer with a vinyl end group, acrylic acid, azobisisobutyronitrile and mercaptopropionic acid were subjected to free radical polymerization in benzene at 70°C for 4 hours, wherein the molar ratio of the long-chain imidazolyl ionic liquid monomer with a vinyl end group, acrylic acid, azobisisobutyronitrile and mercaptopropionic acid was 1:2:0.04:0.1, and the concentration of the long-chain imidazolyl ionic liquid monomer with a vinyl end group in benzene was 0.9 mol / L.

[0032] (5) The reaction solution is then cooled to 25°C, and the polymer and benzene phases are separated. The upper benzene solvent is separated and collected for recycling. The lower layer is the anti-corrosion liquid polycarboxylate water reducer ( M n = 20600 g / mol), its solid content is 100%, and the structure is as follows: .

[0033] The anti-corrosion liquid polycarboxylate water reducer prepared in this embodiment 1 H NMR spectrum Figure 1 shown.

[0034] Example 2

[0035] A method for preparing an anti-corrosion liquid polycarboxylate water-reducing agent comprises the following steps: (1) In an ice-water bath, polyethylene glycol monomethyl ether (degree of polymerization: 4) and triethylamine were added to diethyl ether, and stirring was started. Methanesulfonyl chloride was then added and the mixture was reacted at 25°C for 24 h. After filtration, the diethyl ether was removed by vacuum distillation. The crude product was dissolved in dichloromethane and extracted three times with deionized water to obtain polyethylene glycol monomethyl ether methanesulfonate, wherein the molar ratio of polyethylene glycol monomethyl ether, triethylamine, and methanesulfonyl chloride was 1:1:1, and the concentration of polyethylene glycol monomethyl ether in diethyl ether was 1 mol / L.

[0036] (2) Sodium hydroxide, tetraethylammonium bromide, imidazole and polyethylene glycol monomethyl ether methanesulfonate were added to water under ice-water bath conditions, reacted at 25°C for 24 hours, extracted with dichloromethane three times, and then dichloromethane was removed by rotary evaporation to obtain single-terminal imidazole-based polyethylene glycol monomethyl ether, wherein the molar ratio of sodium hydroxide, tetraethylammonium bromide, imidazole and polyethylene glycol monomethyl ether methanesulfonate was 105:0.31:10.5:8, and the concentration of polyethylene glycol monomethyl ether methanesulfonate in water was 1 mol / L.

[0037] (3) Under nitrogen protection, single-end imidazolyl polyethylene glycol monomethyl ether and 2-bromoethyl acrylate were added to anhydrous acetonitrile and reacted at 40°C for 50 hours. The imidazolyl ionic liquid monomer with a long-chain structure having a vinyl end group was obtained by rotary evaporation purification, wherein the molar ratio of single-end imidazolyl polyethylene glycol monomethyl ether to 2-bromoethyl acrylate was 1:1.05, and the concentration of single-end imidazolyl polyethylene glycol monomethyl ether in anhydrous acetonitrile was 0.75 mol / L.

[0038] (4) Under nitrogen protection, a long-chain imidazolyl ionic liquid monomer with a vinyl end group, acrylic acid, azobisisoheptanonitrile and mercaptoethanol were subjected to a free radical polymerization reaction in benzene at 65°C for 3 hours, wherein the molar ratio of the long-chain imidazolyl ionic liquid monomer with a vinyl end group, acrylic acid, azobisisoheptanonitrile and mercaptoethanol was 1:2:0.02:0.08, and the concentration of the long-chain imidazolyl ionic liquid monomer with a vinyl end group in benzene was 1.1 mol / L.

[0039] (5) The reaction solution is then cooled to 25°C, and the polymer and benzene phases are separated. The upper benzene solvent is separated and collected for recycling. The lower layer is the anti-corrosion liquid polycarboxylate water reducer ( M n = 18600 g / mol), its solid content is 100%, and the structure is as follows: .

[0040] Example 3

[0041] A method for preparing an anti-corrosion liquid polycarboxylate water-reducing agent comprises the following steps: (1) In an ice-water bath, polyethylene glycol monomethyl ether (degree of polymerization: 18) and triethylamine were added to diethyl ether, and stirring was started. Methanesulfonyl chloride was then added and the mixture was reacted at 25°C for 48 h. After filtration, the diethyl ether was removed by vacuum distillation. The crude product was dissolved in dichloromethane and extracted with deionized water five times to obtain polyethylene glycol monomethyl ether methanesulfonate, wherein the molar ratio of polyethylene glycol monomethyl ether, triethylamine, and methanesulfonyl chloride was 1:1:1, and the concentration of polyethylene glycol monomethyl ether in diethyl ether was 1 mol / L.

[0042] (2) Sodium hydroxide, tetraethylammonium bromide, imidazole and polyethylene glycol monomethyl ether methanesulfonate were added to water under ice-water bath conditions, reacted at 25°C for 48 hours, extracted with dichloromethane five times, and then dichloromethane was removed by rotary evaporation to obtain single-terminal imidazole-based polyethylene glycol monomethyl ether, wherein the molar ratio of sodium hydroxide, tetraethylammonium bromide, imidazole and polyethylene glycol monomethyl ether methanesulfonate was 110:0.33:11:8, and the concentration of polyethylene glycol monomethyl ether methanesulfonate in water was 1 mol / L.

[0043] (3) Under nitrogen protection, single-end imidazolyl polyethylene glycol monomethyl ether and 2-bromoethyl acrylate were added to anhydrous acetonitrile and reacted at 50°C for 45 hours. The imidazolyl ionic liquid monomer with a long-chain structure having a vinyl end group was obtained by rotary evaporation purification, wherein the molar ratio of single-end imidazolyl polyethylene glycol monomethyl ether to 2-bromoethyl acrylate was 1:1.1, and the concentration of single-end imidazolyl polyethylene glycol monomethyl ether in anhydrous acetonitrile was 0.75 mol / L.

[0044] (4) Under nitrogen protection, a long-chain imidazolyl ionic liquid monomer with a vinyl end group, acrylic acid, methacrylic acid, dimethyl azobisisobutyrate and n-dodecyl mercaptan were subjected to a free radical polymerization reaction in p-xylene at 85°C for 5 hours, wherein the molar ratio of the long-chain imidazolyl ionic liquid monomer with a vinyl end group, acrylic acid, methacrylic acid, dimethyl azobisisobutyrate and n-dodecyl mercaptan was 1:4:1:0.1:0.16, and the concentration of the long-chain imidazolyl ionic liquid monomer with a vinyl end group in p-xylene was 0.5 mol / L.

[0045] (5) The reaction solution is then cooled to 25°C, and the polymer and p-xylene phases are separated. The upper p-xylene solvent is separated and collected for recycling. The lower layer is the anti-corrosion liquid polycarboxylate water reducer ( M n = 35700 g / mol), its solid content is 100%, and the structure is as follows: .

[0046] Example 4

[0047] A method for preparing an anti-corrosion liquid polycarboxylate water-reducing agent comprises the following steps: (1) In an ice-water bath, polyethylene glycol monomethyl ether (degree of polymerization: 10) and triethylamine were added to diethyl ether, and stirring was started. Methanesulfonyl chloride was then added and the mixture was reacted at 25°C for 36 h. After filtration, the diethyl ether was removed by vacuum distillation. The crude product was dissolved in dichloromethane and extracted four times with deionized water to obtain polyethylene glycol monomethyl ether methanesulfonate, wherein the molar ratio of polyethylene glycol monomethyl ether, triethylamine, and methanesulfonyl chloride was 1:1:1, and the concentration of polyethylene glycol monomethyl ether in diethyl ether was 1 mol / L.

[0048] (2) Sodium hydroxide, tetraethylammonium bromide, imidazole and polyethylene glycol monomethyl ether methanesulfonate were added to water under ice-water bath conditions, reacted at 25°C for 36 hours, extracted with dichloromethane four times, and then dichloromethane was removed by rotary evaporation to obtain single-terminal imidazole-based polyethylene glycol monomethyl ether, wherein the molar ratio of sodium hydroxide, tetraethylammonium bromide, imidazole and polyethylene glycol monomethyl ether methanesulfonate was 100:0.3:10:8, and the concentration of polyethylene glycol monomethyl ether methanesulfonate in water was 1 mol / L.

[0049] (3) Under nitrogen protection, single-end imidazolyl polyethylene glycol monomethyl ether (degree of polymerization: 10) and 2-bromoethyl acrylate were added to anhydrous acetonitrile and reacted at 45°C for 48 hours. The imidazolyl ionic liquid monomer with a long-chain structure having a vinyl end group was obtained by rotary evaporation purification, wherein the molar ratio of single-end imidazolyl polyethylene glycol monomethyl ether to 2-bromoethyl acrylate was 1:1, and the concentration of single-end imidazolyl polyethylene glycol monomethyl ether in anhydrous acetonitrile was 0.75 mol / L.

[0050] (4) Under nitrogen protection, a long-chain imidazolyl ionic liquid monomer with a vinyl end group, maleic acid, azobisisobutyronitrile and mercaptopropionic acid were subjected to free radical polymerization in benzene at 75°C for 4 hours, wherein the molar ratio of the long-chain imidazolyl ionic liquid monomer with a vinyl end group, maleic acid, azobisisobutyronitrile and mercaptopropionic acid was 1:3:0.06:0.12, and the concentration of the long-chain imidazolyl ionic liquid monomer with a vinyl end group in benzene was 0.7 mol / L.

[0051] (5) The reaction solution is then cooled to 25°C, and the polymer and benzene phases are separated. The upper benzene solvent is separated and collected for recycling. The lower layer is the anti-corrosion liquid polycarboxylate water reducer ( M n = 26200 g / mol), its solid content is 100%, and the structure is as follows: .

[0052] Example 5

[0053] A method for preparing an anti-corrosion liquid polycarboxylate water-reducing agent comprises the following steps: (1) In an ice-water bath, polyethylene glycol monomethyl ether (degree of polymerization: 14) and triethylamine were added to diethyl ether, and stirring was started. Methanesulfonyl chloride was then added and the mixture was reacted at 25°C for 48 h. After filtration, the diethyl ether was removed by vacuum distillation. The crude product was dissolved in dichloromethane and extracted four times with deionized water to obtain polyethylene glycol monomethyl ether methanesulfonate, wherein the molar ratio of polyethylene glycol monomethyl ether, triethylamine, and methanesulfonyl chloride was 1:1:1, and the concentration of polyethylene glycol monomethyl ether in diethyl ether was 1 mol / L.

[0054] (2) Sodium hydroxide, tetraethylammonium bromide, imidazole and polyethylene glycol monomethyl ether methanesulfonate were added to water under ice-water bath conditions, reacted at 25°C for 48 hours, extracted with dichloromethane four times, and then dichloromethane was removed by rotary evaporation to obtain single-terminal imidazole-based polyethylene glycol monomethyl ether, wherein the molar ratio of sodium hydroxide, tetraethylammonium bromide, imidazole and polyethylene glycol monomethyl ether methanesulfonate was 100:0.3:10:8, and the concentration of polyethylene glycol monomethyl ether methanesulfonate in water was 1 mol / L.

[0055] (3) Under nitrogen protection, single-end imidazolyl polyethylene glycol monomethyl ether and 2-bromoethyl acrylate were added to anhydrous acetonitrile and reacted at 45°C for 48 hours. The imidazolyl ionic liquid monomer with a long-chain structure having a vinyl end group was obtained by rotary evaporation purification, wherein the molar ratio of single-end imidazolyl polyethylene glycol monomethyl ether to 2-bromoethyl acrylate was 1:1, and the concentration of single-end imidazolyl polyethylene glycol monomethyl ether in anhydrous acetonitrile was 0.75 mol / L.

[0056] (4) Under nitrogen protection, a long-chain imidazolyl ionic liquid monomer with a vinyl end group, maleic acid, maleic acid monomethyl ester, azobisisobutyronitrile and mercaptoethanol were subjected to free radical polymerization in toluene at 80°C for 5 hours, wherein the molar ratio of the long-chain imidazolyl ionic liquid monomer with a vinyl end group, maleic acid, maleic acid monomethyl ester, azobisisobutyronitrile and mercaptoethanol was 1:3:1:0.08:0.14, and the concentration of the long-chain imidazolyl ionic liquid monomer with a vinyl end group in toluene was 0.6 mol / L.

[0057] (5) The reaction solution is then cooled to 25°C, and the polymer and toluene phases are separated. The upper toluene solvent is separated and collected for recycling. The lower layer is the anti-corrosion liquid polycarboxylate water reducer. M n = 29800 g / mol), its solid content is 100%, and the structure is as follows: .

[0058] Example 6

[0059] A method for preparing an anti-corrosion liquid polycarboxylate water-reducing agent comprises the following steps: (1) In an ice-water bath, polyethylene glycol monomethyl ether (degree of polymerization: 7) and triethylamine were added to diethyl ether, and stirring was started. Methanesulfonyl chloride was then added and the mixture was reacted at 25°C for 24 h. After filtration, the diethyl ether was removed by vacuum distillation. The crude product was dissolved in dichloromethane and extracted four times with deionized water to obtain polyethylene glycol monomethyl ether methanesulfonate, wherein the molar ratio of polyethylene glycol monomethyl ether, triethylamine, and methanesulfonyl chloride was 1:1:1, and the concentration of polyethylene glycol monomethyl ether in diethyl ether was 1 mol / L.

[0060] (2) Sodium hydroxide, tetraethylammonium bromide, imidazole and polyethylene glycol monomethyl ether methanesulfonate were added to water under ice-water bath conditions, reacted at 25°C for 24 hours, extracted with dichloromethane four times, and then dichloromethane was removed by rotary evaporation to obtain single-terminal imidazole-based polyethylene glycol monomethyl ether, wherein the molar ratio of sodium hydroxide, tetraethylammonium bromide, imidazole and polyethylene glycol monomethyl ether methanesulfonate was 100:0.3:10:8, and the concentration of polyethylene glycol monomethyl ether methanesulfonate in water was 1 mol / L.

[0061] (3) Under nitrogen protection, single-end imidazolyl polyethylene glycol monomethyl ether and 2-bromoethyl acrylate were added to anhydrous acetonitrile and reacted at 45°C for 48 hours. The imidazolyl ionic liquid monomer with a long-chain structure having a vinyl end group was obtained by rotary evaporation purification, wherein the molar ratio of single-end imidazolyl polyethylene glycol monomethyl ether to 2-bromoethyl acrylate was 1:1, and the concentration of single-end imidazolyl polyethylene glycol monomethyl ether in anhydrous acetonitrile was 0.75 mol / L.

[0062] (4) Under nitrogen protection, a long-chain imidazolyl ionic liquid monomer with a vinyl end group, acrylic acid, methyl acrylate, azobisisobutyronitrile and mercaptoethanol were subjected to free radical polymerization in benzene at 70°C for 5 hours, wherein the molar ratio of the long-chain imidazolyl ionic liquid monomer with a vinyl end group, acrylic acid, methyl acrylate, azobisisobutyronitrile and mercaptoethanol was 1:2:0.5:0.05:0.12, and the concentration of the long-chain imidazolyl ionic liquid monomer with a vinyl end group in benzene was 0.9 mol / L.

[0063] (5) The reaction solution is then cooled to 25°C, and the polymer and benzene phases are separated. The upper benzene solvent is separated and collected for recycling. The lower layer is the anti-corrosion liquid polycarboxylate water reducer ( M n = 22700 g / mol), its solid content is 100%, and the structure is as follows: .

[0064] Comparative Example 1

[0065] A method for preparing a polycarboxylate water-reducing agent comprises the following steps: Under nitrogen protection, polyethylene glycol monomethyl ether acrylate (480 g / mol), acrylic acid, azobisisobutyronitrile and mercaptopropionic acid were subjected to free radical polymerization in benzene at 70°C for 4 hours. The molar ratio of polyethylene glycol monomethyl ether acrylate, acrylic acid, azobisisobutyronitrile and mercaptopropionic acid was 1:2:0.04:0.1, and the concentration of polyethylene glycol monomethyl ether acrylate in benzene was 1 mol / L. Since stratification would not occur after cooling, the benzene solvent needed to be evaporated, and the mixture was dried and crushed to obtain a powdered polycarboxylate water reducer.

[0066] Comparative Example 2

[0067] The polycarboxylate water-reducing agent prepared in Comparative Example 1 was prepared into a solution with a solid content of 50%, and 5‰ of a Kathon preservative was added.

[0068] Test Example 1

[0069] Concrete performance test: referring to GB8076-2008 "Concrete Admixtures", the samples obtained from each embodiment and comparative example were added into concrete as concrete admixtures, and the concrete mix ratio (kg / m 3 ) is cement: sand: small stone: medium stone: water = 360:920:240:718:162, and the slump and time-varying amount of concrete and compressive strength are measured. The water-reducing agent dosage is 0.12% of the cementitious material (solid content). The specific test results are shown in Table 1.

[0070]

[0071] From the data in Table 1, it can be seen that the anti-corrosion liquid polycarboxylate water-reducers prepared in Examples 1 to 6 have improved dispersion, dispersion retention performance and compressive strength in concrete to varying degrees compared with the conventional polycarboxylate water-reducers prepared in Comparative Examples 1 and 2.

[0072] Test Example 2

[0073] Anticorrosion Testing: The polycarboxylate water-reducers prepared in each Example and Comparative Example were diluted to a 15% solids content and compounded with sugar and sodium gluconate to obtain finished water-reducers. The mass concentrations of sugar and sodium gluconate in the finished water-reducers were 1% and 2%, respectively. 250g of each finished product was placed in a 500mL beaker and placed in a 30°C incubator for 15, 30, 60, 90, and 120 days. The samples were observed at the corresponding time intervals for signs of odor, turbidity, or mold growth to compare the anticorrosion performance of the samples. Specific test results are shown in Table 2.

[0074]

[0075] The data in Table 2 show that Examples 1-6 showed no signs of spoilage within 120 days. However, Comparative Example 1 exhibited significant spoilage, including an unpleasant odor and mildew growth, at 30 days. Comparative Example 2, which was directly compounded with a Kasson preservative, exhibited slightly better antiseptic properties than Comparative Example 1, with spoilage not appearing until 120 days, with the initial development of an unpleasant odor and slight mildew growth. This demonstrates that the antiseptic liquid polycarboxylate water-reducing agent prepared by the present invention exhibits excellent antiseptic properties.

[0076] In summary, compared to the prior art, the corrosion-resistant liquid polycarboxylate water-reducing agent prepared by the present invention is a polycarboxylate water-reducing agent with inherent corrosion and antibacterial properties, obtained by free radical polymerization of a long-chain imidazolyl ionic liquid monomer with vinyl end groups with an unsaturated acid small monomer, an initiator, and a chain transfer agent. This polycarboxylate water-reducing agent eliminates the need for additional preservatives, maintaining the polycarboxylate water-reducing agent for extended periods. Furthermore, the imidazolyl polyionic liquid polycarboxylate water-reducing agent exhibits temperature-sensitive properties: it is miscible with benzene-based solvents at high temperatures and separates into two phases upon cooling to room temperature. A 100% solids liquid polycarboxylate water-reducing agent can be directly obtained through simple layering, resulting in simple and convenient post-processing. Compared to common liquid polycarboxylate water-reducing agents on the market (10% to 50% solids content), this agent significantly reduces transportation and storage costs. Compared to conventional solid water-reducing agents (≥95% solids content), it offers improved solubility. Furthermore, the benzene-based solvent can be reused, reducing production costs while also aligning with current green and environmentally friendly production practices.

[0077] The above-mentioned detailed description of an anti-corrosion liquid polycarboxylate water-reducing agent, its preparation method and application with reference to the embodiments is illustrative rather than restrictive. Several embodiments can be listed according to the limited scope. Therefore, changes and modifications without departing from the overall concept of the present invention should fall within the scope of protection of the present invention.

Claims

1. An anti-corrosion liquid polycarboxylate water reducer, characterized in that: The anti-corrosion liquid polycarboxylate water reducer has the following structure: Wherein, R1 represents H or CH3, R2 represents one of H, COOH or COOCH3; x, y, and n are all integers, and x:y=(2~5):1, y is from 20~50, and n is from 4~18.

2. A method for preparing the anti-corrosion liquid polycarboxylate water-reducing agent according to claim 1, characterized in that: The preparation method comprises the following steps: Step 1: Under nitrogen protection, a long-chain imidazolyl ionic liquid monomer with a vinyl end group, an unsaturated carboxylic acid small monomer, an initiator and a chain transfer agent are subjected to a free radical polymerization reaction in a benzene solvent at 65-85°C for 3-5 hours; Step 2: Cool the reaction solution to below 25°C, and the polymer and the benzene solvent will separate. The upper benzene solvent will be separated, collected and recycled, and the lower layer will be the anti-corrosion liquid polycarboxylate water reducer.

3. The preparation method according to claim 2, characterized in that In step 1, the molar ratio of the imidazole-based ionic liquid monomer with a long chain structure having a vinyl end group, the unsaturated acid small monomer, the initiator and the chain transfer is 1: (2-5): (0.02-0.1): (0.08-0.16).

4. The preparation method according to claim 2, characterized in that In step 1, the structural formula of the imidazolyl ionic liquid monomer having a long chain structure with a vinyl end group is: 。 5. The preparation method according to any one of claims 2 to 4, characterized in that The preparation method of the imidazolium-based ionic liquid monomer having a long-chain structure with a vinyl end group comprises the following steps: Step S1: In an ice-water bath, sodium hydroxide, tetraethylammonium bromide, imidazole and polyethylene glycol monomethyl ether methanesulfonate are added to water, reacted at room temperature for 24 to 48 hours, and subjected to extraction, concentration and drying to obtain single-terminal imidazole-based polyethylene glycol monomethyl ether; the structural formula of the single-terminal imidazole-based polyethylene glycol monomethyl ether is: ; Step S2: Under nitrogen protection, single-end imidazole polyethylene glycol monomethyl ether and 2-bromoethyl acrylate are added to anhydrous acetonitrile, reacted at 40-50° C. for 45-50 hours, and purified to obtain a long-chain imidazole ionic liquid monomer with a vinyl end group.

6. The preparation method according to claim 5, characterized in that In step S1, the molar ratio of sodium hydroxide, tetraethylammonium bromide, imidazole, and polyethylene glycol monomethyl ether methanesulfonate is (100-110): (0.3-0.33): (10-11):

8.

7. The preparation method according to claim 5, characterized in that In step S2, the molar ratio of the single-terminal imidazole polyethylene glycol monomethyl ether to 2-bromoethyl acrylate is 1:(1-1.1).

8. The preparation method according to any one of claims 2 to 4, characterized in that: In step 1, the unsaturated carboxylic acid small monomer is at least one of acrylic acid, methacrylic acid, maleic acid or monomethyl maleate; the initiator is azobisisobutyronitrile, azobisisoheptanenitrile or dimethyl azobisisobutyrate; and the chain transfer agent is at least one of mercaptopropionic acid, mercaptoethanol or n-dodecyl mercaptan.

9. The preparation method according to any one of claims 2 to 4, characterized in that: In step 1, the benzene-based solvent is at least one of benzene, toluene, and p-xylene.

10. Use of the anti-corrosion liquid polycarboxylate water-reducing agent according to claim 1 as a concrete admixture.

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