A terpolymer water treatment agent, its preparation method and application

Abstract

The application discloses a kind of ternary copolymer water treatment agent and its preparation method and application, belong to water treatment chemical technical field.The water treatment agent is prepared by water phase free radical copolymerization of sodium carboxymethyl cellulose, epoxy succinic acid and hydroxypropyl acrylate, and the mass ratio of the three is 1:1~3.5:1~2;Preparation process includes dissolving, nitrogen deoxygenation, temperature rising, copolymerization droping, heat preservation and pH adjustment and the like steps, and the process condition is mild.The product of the application is phosphorus-free, biodegradable, three kinds of functional groups play a synergistic role, has good scale inhibition, corrosion inhibition and dispersion comprehensive performance, and can be widely used in industrial water system.

Description

Technical Field

[0001] This invention belongs to the field of water treatment chemicals technology, specifically relating to a ternary copolymer water treatment agent prepared by aqueous phase free radical copolymerization using sodium carboxymethyl cellulose, epoxy succinic acid and hydroxypropyl acrylate as monomer raw materials, as well as the preparation method of the water treatment agent and its application in industrial water treatment. Background Technology

[0002] During operation, industrial cooling water, boiler water, and oilfield reinjection water systems experience a concentration of calcium and magnesium ions, which easily precipitate as calcium carbonate, calcium sulfate, and calcium phosphate, depositing as scale on the inner walls of equipment and pipes. Simultaneously, dissolved oxygen and corrosive ions in the water accelerate the corrosion of metal equipment. If suspended solids such as iron oxides in the water are not effectively dispersed, under-scale corrosion will be further aggravated. These problems lead to decreased heat exchange efficiency, pipe blockage, and equipment damage, causing significant economic losses and safety hazards. Therefore, in industrial production, water treatment agents are typically added to the water system to simultaneously achieve scale inhibition, corrosion inhibition, and dispersion functions.

[0003] Traditional phosphorus-based water treatment agents, such as HEDP and ATMP, are organophosphates with good overall performance. However, their phosphorus-containing structure leads to the discharge of large amounts of phosphorus-containing wastewater into water bodies, causing eutrophication, algal blooms, and oxygen depletion, among other serious environmental problems. In recent years, with increasingly stringent controls on total phosphorus discharge concentrations in industrial wastewater across various regions, the research and development of phosphorus-free and environmentally friendly water treatment agents has received widespread attention.

[0004] Existing phosphorus-free water treatment agents mainly include polyepoxysuccinic acid, polyaspartic acid, and polyacrylic acid. Although they have the advantages of being phosphorus-free and biodegradable, the above-mentioned single-component agents generally have the disadvantage of single function: those that are good at scale inhibition have insufficient corrosion inhibition, and those that are good at corrosion inhibition have poor scale inhibition. It is difficult to meet the comprehensive needs of industrial circulating water systems for scale inhibition, corrosion inhibition, and dispersion at the same time.

[0005] Sodium carboxymethyl cellulose (CMC) is a natural polymer derivative with numerous carboxymethyl side chains and good water solubility. It exhibits certain dispersing and scale-inhibiting effects in water treatment, but its corrosion-inhibiting performance is limited when used alone. The applicant has conducted extensive research on CMC as a monomer for water treatment polymers, achieving some results, such as CN116282596A and CN116462802A, but the overall performance remains unsatisfactory.

[0006] Based on the above, it is necessary to continue exploring water treatment agents with better overall performance. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to provide a ternary copolymer water treatment agent with sodium carboxymethyl cellulose, epoxy succinic acid and hydroxypropyl acrylate as monomers. Through the synergistic copolymerization of the three monomers, the scale inhibition, corrosion inhibition and dispersion functions are organically unified, and it is also phosphorus-free, biodegradable and environmentally friendly.

[0008] To solve the above problems, the technical solution adopted by the present invention is as follows:

[0009] In a first aspect, the present invention provides a ternary copolymer water treatment agent, wherein the water treatment agent is prepared by aqueous phase free radical copolymerization of three monomers: sodium carboxymethyl cellulose, epoxy succinic acid and hydroxypropyl acrylate; the mass ratio of sodium carboxymethyl cellulose, epoxy succinic acid and hydroxypropyl acrylate is 1:1 to 3.5:1 to 2 by mass.

[0010] In a preferred embodiment of the present invention, the mass ratio of sodium carboxymethyl cellulose, epoxy succinic acid and hydroxypropyl acrylate is 1:2:1.

[0011] Secondly, the present invention provides a method for preparing the above-mentioned ternary copolymer water treatment agent, characterized in that it includes the following steps:

[0012] S1. Dissolving: Add sodium carboxymethyl cellulose to deionized water and stir at room temperature until completely dissolved to obtain a homogeneous viscous liquid;

[0013] S2, Deoxygenation: Nitrogen gas is introduced into the solution obtained in step S1 at a flow rate of 0.5 to 1.0 L / min for 30 to 40 min to completely remove dissolved oxygen from the system.

[0014] S3. Preheating: Heat the system obtained in step S2 to 60-80°C and keep it at a constant temperature while stirring.

[0015] S4. Adding copolymerization: First, dissolve epoxy succinic acid in water to obtain an epoxy succinic acid solution, then mix it evenly with hydroxypropyl acrylate to obtain a mixed monomer solution; dissolve ammonium persulfate in a small amount of deionized water to obtain an ammonium persulfate solution; simultaneously and uniformly add the mixed monomer solution and the ammonium persulfate solution to the system obtained in step S3, and control the adding time to 0.5-2h.

[0016] S5. Heat preservation: After the addition is complete, heat the system to 80-90℃ and keep it at this temperature for 3-5 hours.

[0017] S6. Post-treatment: Cool the reaction system to room temperature and adjust the pH to 6.5-7.5 with an alkaline solution to obtain the ternary copolymer water treatment agent.

[0018] In a preferred embodiment of the present invention, the mass ratio of sodium carboxymethyl cellulose and deionized water in step S1 is 2-3:100.

[0019] In a preferred embodiment of the present invention, in step S4, the amount of ammonium persulfate used is 1% to 3% of the total mass of the three monomers.

[0020] In a preferred embodiment of the present invention, in step S4, the concentration of the ammonium persulfate solution is 8-15%.

[0021] In a preferred embodiment of the present invention, in step S4, the concentration of the epoxy succinic acid is 8-15%.

[0022] In a preferred embodiment of the present invention, in step S6, the alkaline solution is a 30% sodium hydroxide solution.

[0023] In a third aspect, the present invention provides the application of the above-mentioned ternary copolymer water treatment agent in industrial water treatment.

[0024] As some preferred embodiments of the present invention, the ternary copolymer water treatment agent is directly added to industrial water at a dosage of 5-100 mg / L; the industrial water is at least one of industrial circulating cooling water, boiler water, or oilfield reinjection water.

[0025] The beneficial effects of adopting the above technical solution are as follows:

[0026] 1. This invention uses sodium carboxymethyl cellulose, epoxy succinic acid, and hydroxypropyl acrylate as raw materials. The product is phosphorus-free, nitrogen-free, biodegradable, and will not cause eutrophication of water bodies. It meets the requirements of green development and can replace traditional phosphorus-based water treatment agents, solving the problem of phosphorus-containing wastewater pollution at the source.

[0027] 2. This invention integrates three functional groups—scale inhibitor, corrosion inhibitor, and dispersant—into the same molecular chain through ternary copolymerization, using only ammonium persulfate as an initiator to obtain polymers of suitable size. Verification has shown that these polymers possess good comprehensive performance in scale inhibition, corrosion inhibition, and dispersion.

[0028] 3. This invention uses an aqueous free radical copolymerization process, in which the reaction is carried out in an aqueous solution at 60-90℃. It does not require high temperature and high pressure or special equipment, is easy to operate, has a wide range of raw material sources, and is easy to mass-produce in the industrial sector.

[0029] 4. This invention can be widely applied to various industrial water treatment systems such as industrial circulating cooling water, boiler water, and oilfield reinjection water, and has good application prospects. Attached Figure Description

[0030] Figure 1 This is the infrared spectrum of Example 6 of the present invention; wherein, a is sodium carboxymethyl cellulose; b is a terpolymer;

[0031] Figure 2This is an EDS surface distribution diagram of Embodiment 6 of the present invention; wherein, a represents element C; b represents element O; and c represents element Na;

[0032] Figure 3 This is the XPS spectrum of Embodiment 6 of the present invention; wherein, a is the full spectrum; b is C 1s; c is O 1s; and d is Na 1s. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of the present invention clearer, the invention will be described clearly and completely below in conjunction with specific embodiments.

[0034] All raw materials used in the embodiments were commercially available, with the following specifications: sodium carboxymethyl cellulose (CMC), degree of substitution 0.7–0.9, viscosity (1% aqueous solution, 25°C) 800–1200 mPa·s; epoxy succinic acid (ESA), purity ≥97%; hydroxypropyl acrylate (HPA), purity ≥98%; ammonium persulfate, analytical grade; sodium bisulfite, analytical grade; NaOH, analytical grade.

[0035] Performance testing standards

[0036] The performance of the reagent in inhibiting calcium carbonate scale was determined according to GB / T16632-2008; the performance in inhibiting calcium phosphate scale was determined according to GB / T22626-2008; the performance in dispersing iron oxides was evaluated by testing the dispersion performance of the reagent on iron oxide, with 100% transmittance of distilled water as a reference, and the lower the transmittance, the better the dispersion performance; the corrosion inhibition performance of carbon steel was tested according to the rotating plate loss method in GB / T 18175-2014, and the corrosion inhibition rate was calculated from the corrosion rate. The corrosion rate of carbon steel must meet the requirement of less than 0.075 mm / a in GB 50050-2017 "Design Code for Industrial Circulating Cooling Water Treatment".

[0037] Example 1

[0038] A ternary copolymer water treatment agent is polymerized from CMC, ESA, and HPA in a mass ratio of 1:2:1. The preparation steps are as follows:

[0039] S1. Add 10g of CMC to 400g of deionized water and stir at room temperature for 30 minutes to form a homogeneous viscous liquid.

[0040] S2. Nitrogen gas is introduced into the above CMC aqueous solution at a flow rate of 0.8 L / min for 30 min to remove dissolved oxygen from the system.

[0041] S3. Heat the system to 75°C and maintain constant temperature while stirring at a stirring rate of 250 r / min.

[0042] S4. Dissolve 20g ESA in 200ml of water, and then mix it with 10g HPA to obtain a mixed monomer solution. Dissolve 0.8g ammonium persulfate in 8ml of deionized water to obtain an ammonium persulfate solution. Use a syringe pump to simultaneously and uniformly add the mixed monomer solution and the ammonium persulfate solution to the S3 constant temperature system for 1 hour.

[0043] S5. After the addition is complete, heat the system to 85°C and keep it at that temperature for 3 hours.

[0044] S6. After cooling to room temperature, adjust the pH to 7.0 with 30% NaOH solution to obtain a light yellow transparent liquid ternary copolymer water treatment agent.

[0045] Performance test results: Calcium carbonate scale inhibition performance test: with a water treatment agent addition of 10 ppm, the calcium carbonate scale inhibition rate was 98.3%; calcium phosphate scale inhibition performance test: with a water treatment agent addition of 5 ppm, the calcium phosphate scale inhibition rate was 100%; iron oxide dispersion performance test: with a water treatment agent addition of 5 ppm, the iron oxide dispersion transmittance was 27.5%; carbon steel corrosion inhibition performance test: with a water treatment agent addition of 100 ppm, the carbon steel corrosion inhibition rate was 93.6%.

[0046] Example 2

[0047] A ternary copolymer water treatment agent is polymerized from CMC, ESA, and HPA in a mass ratio of 1:3.5:1. The preparation steps are as follows:

[0048] S1. Add 8g of CMC to 320g of deionized water and stir at room temperature for 30 minutes to form a homogeneous viscous liquid.

[0049] S2. Nitrogen gas is introduced into the above CMC aqueous solution at a flow rate of 0.8 L / min for 30 min to remove dissolved oxygen from the system.

[0050] S3. Heat the system to 75°C and maintain constant temperature while stirring at a stirring rate of 250 r / min.

[0051] S4. Dissolve 28g ESA in 280ml of water, and then mix it with 8g HPA to obtain a mixed monomer solution. Dissolve 0.88g ammonium persulfate in 8ml of deionized water to obtain an ammonium persulfate solution. Use a syringe pump to simultaneously and uniformly add the mixed monomer solution and the ammonium persulfate solution to the S3 constant temperature system for 1 hour.

[0052] S5. After the addition is complete, heat the system to 85°C and keep it at that temperature for 3 hours.

[0053] S6. After cooling to room temperature, adjust the pH to 7.0 with 30% NaOH solution to obtain a pale yellow transparent liquid ternary copolymer water treatment agent.

[0054] Performance test results: Calcium carbonate scale inhibition performance test: with a water treatment agent addition of 10 ppm, the calcium carbonate scale inhibition rate was 95.7%; calcium phosphate scale inhibition performance test: with a water treatment agent addition of 5 ppm, the calcium phosphate scale inhibition rate was 97.2%; iron oxide dispersion performance test: with a water treatment agent addition of 5 ppm, the iron oxide dispersion transmittance was 35.0%; carbon steel corrosion inhibition performance test: with a water treatment agent addition of 100 ppm, the carbon steel corrosion inhibition rate was 85.2%.

[0055] Example 3

[0056] A ternary copolymer water treatment agent is polymerized from CMC, ESA, and HPA in a mass ratio of 1:1.5:1.5. The preparation steps are as follows:

[0057] S1. Add 10g of CMC to 400g of deionized water and stir at room temperature for 30 minutes to form a homogeneous viscous liquid.

[0058] S2. Nitrogen gas is introduced into the above CMC aqueous solution at a flow rate of 0.8 L / min for 30 min to remove dissolved oxygen from the system.

[0059] S3. Heat the system to 75°C and maintain constant temperature while stirring at a stirring rate of 250 r / min.

[0060] S4. Dissolve 15g ESA in 150ml of water, and then mix it with 150g HPA to obtain a mixed monomer solution; dissolve 0.8g ammonium persulfate in 8ml of deionized water to obtain an ammonium persulfate solution; use a syringe pump to simultaneously and uniformly add the mixed monomer solution and ammonium persulfate solution to the S3 constant temperature system for 1 hour.

[0061] S5. After the addition is complete, heat the system to 85°C and keep it at that temperature for 3 hours.

[0062] S6. After cooling to room temperature, adjust the pH to 7.0 with 30% NaOH solution to obtain a pale yellow transparent liquid ternary copolymer water treatment agent.

[0063] Performance test results: Calcium carbonate scale inhibition performance test: with a water treatment agent addition of 10 ppm, the calcium carbonate scale inhibition rate was 92.1%; Calcium phosphate scale inhibition performance test: with a water treatment agent addition of 5 ppm, the calcium phosphate scale inhibition rate was 100%; Iron oxide dispersion performance test: with a water treatment agent addition of 5 ppm, the iron oxide dispersion transmittance was 28.0%; Carbon steel corrosion inhibition performance test: with a water treatment agent addition of 100 ppm, the carbon steel corrosion inhibition rate was 90.5%.

[0064] Example 4

[0065] A ternary copolymer water treatment agent is polymerized from CMC, ESA, and HPA in a mass ratio of 1:2:1.5. The preparation steps are as follows:

[0066] S1. Add 10g of CMC to 400g of deionized water and stir at room temperature for 30 minutes to form a homogeneous viscous liquid.

[0067] S2. Nitrogen gas is introduced into the above CMC aqueous solution at a flow rate of 0.8 L / min for 30 min to remove dissolved oxygen from the system.

[0068] S3. Heat the system to 75°C and maintain constant temperature while stirring at a stirring rate of 250 r / min.

[0069] S4. Dissolve 20g ESA in 200ml of water, and then mix it with 15g HPA to obtain a mixed monomer solution; dissolve 0.45g ammonium persulfate in 8ml of deionized water to obtain an ammonium persulfate solution; use a syringe pump to simultaneously and uniformly add the mixed monomer solution and ammonium persulfate solution to the S3 constant temperature system for 1 hour.

[0070] S5. After the addition is complete, heat the system to 85°C and keep it at that temperature for 4 hours.

[0071] S6. After cooling to room temperature, adjust the pH to 7.0 with 30% NaOH solution to obtain a pale yellow transparent liquid ternary copolymer water treatment agent.

[0072] Performance test results: Calcium carbonate scale inhibition performance test: with a water treatment agent addition of 10 ppm, the calcium carbonate scale inhibition rate was 96.7%; calcium phosphate scale inhibition performance test: with a water treatment agent addition of 5 ppm, the calcium phosphate scale inhibition rate was 96.4%; iron oxide dispersion performance test: with a water treatment agent addition of 5 ppm, the iron oxide dispersion transmittance was 29.0%; carbon steel corrosion inhibition performance test: with a water treatment agent addition of 100 ppm, the carbon steel corrosion inhibition rate was 91.5%.

[0073] Example 5

[0074] A ternary copolymer water treatment agent is polymerized from CMC, ESA, and HPA in a mass ratio of 1:3:2. The preparation steps are as follows:

[0075] S1. Add 10g of CMC to 400g of deionized water and stir at room temperature for 30 minutes to form a homogeneous viscous liquid.

[0076] S2. Nitrogen gas is introduced into the above CMC aqueous solution at a flow rate of 0.8 L / min for 30 min to remove dissolved oxygen from the system.

[0077] S3. Heat the system to 75°C and maintain constant temperature while stirring at a stirring rate of 250 r / min.

[0078] S4. Dissolve 40g ESA in 400ml of water, and then mix it with 20g HPA to obtain a mixed monomer solution. Dissolve 1.8g ammonium persulfate in 8ml of deionized water to obtain an ammonium persulfate solution. Use a syringe pump to simultaneously and uniformly add the mixed monomer solution and the ammonium persulfate solution to the S3 constant temperature system for 1 hour.

[0079] S5. After the addition is complete, heat the system to 85°C and keep it at that temperature for 3 hours.

[0080] S6. After cooling to room temperature, adjust the pH to 7.0 with 30% NaOH solution to obtain a pale yellow transparent liquid ternary copolymer water treatment agent.

[0081] Performance test results: Calcium carbonate scale inhibition performance test: with a water treatment agent addition of 10 ppm, the calcium carbonate scale inhibition rate was 93.4%; calcium phosphate scale inhibition performance test: with a water treatment agent addition of 5 ppm, the calcium phosphate scale inhibition rate was 95.8%; iron oxide dispersion performance test: with a water treatment agent addition of 5 ppm, the iron oxide dispersion transmittance was 31.0%; carbon steel corrosion inhibition performance test: with a water treatment agent addition of 100 ppm, the carbon steel corrosion inhibition rate was 90.8%.

[0082] Example 6

[0083] The ternary copolymer water treatment agent prepared in Example 1 was mixed with 10 times its volume of anhydrous ethanol, stirred for 3 min, and then filtered. The solid product was collected and washed twice with an equal volume of anhydrous ethanol. The washed and purified solid sample was placed in a vacuum drying oven and dried under constant temperature at 60 °C to finally obtain the purified CMC / ESA / HPA ternary copolymer sample. To clarify the sample structure, elemental composition, and surface functional group characteristics, Fourier transform infrared spectroscopy (FTIR), energy dispersive spectroscopy (EDS), and X-ray photoelectron spectroscopy (XPS) were performed. The specific results are as follows.

[0084] FTIR such as Figure 1 As shown, by comparing the infrared spectra of the CMC raw material and the terpolymer, the structural changes of the samples can be clearly observed. The pure CMC raw material at 3400 cm⁻¹... -1 The characteristic absorption peak of the stretching vibration of the hydroxyl group (OH) appears at a wavenumber of 1596 cm⁻¹. -1 The antisymmetric stretching vibration corresponding to -COO- in carboxymethyl groups is located at 1000–1100 cm⁻¹. -1 The absorption peaks in the specified range correspond to the stretching vibrations of the COC ether bonds in the cellulose skeleton, consistent with the standard spectral characteristics of CMC. The infrared spectrum of the terpolymer completely preserves all the characteristic absorption peaks of CMC, demonstrating that the polymerization modification process did not damage the basic molecular skeleton of CMC. Furthermore, the copolymer spectrum shows a peak at 1720 cm⁻¹. -1The addition of a characteristic absorption peak at the C=O group of the ester carbonyl group indicates that the ESA and HPA monomers were successfully grafted onto the CMC molecular chain, achieving ternary copolymer modification. Furthermore, the copolymer exhibits high absorption at 1000–1200 cm⁻¹. -1 The absorption intensity of the carbon-oxygen single bond characteristic region was significantly improved, indicating that the copolymerization reaction introduced a large number of ester and hydroxyl active functional groups into the molecular chain.

[0085] EDS maps and corresponding elemental surface scan results can intuitively reflect the types and distribution of elements on the material surface. The results are as follows: Figure 2 As shown, C, O, and Na elemental signals were detected in the EDS spectrum, and no obvious impurity element peaks were observed, consistent with the elemental composition of the target copolymer. The elemental surface mapping shows that carbon is continuously and uniformly distributed within the scanning observation area, forming the main polymeric framework of the ternary copolymer material; oxygen and sodium elements show no local enrichment, and are uniformly distributed on the material surface in a diffuse state. No obvious component segregation, particle agglomeration, or phase separation was observed throughout the observation field, indicating that after copolymerization modification, oxygen-containing polar functional groups and sodium ions are uniformly dispersed and stably integrated into the polymeric network structure, resulting in good material composition homogeneity.

[0086] XPS testing is used for further precise analysis of the surface elemental composition, functional group types, and chemical bonding forms of samples. Full spectrum scan results are shown below. Figure 3 As shown, the purified terpolymer exhibited only characteristic signal peaks for C, O, and Na elements, with no other impurity element peaks, indicating high sample purity and a perfect match with the theoretical elemental composition of the target terpolymer. Peak fitting of the C 1s high-resolution spectrum yielded three characteristic peaks at 284.8 eV, 286.2 eV, and 288.2 eV, corresponding to the CC / CH bond, CO bond, and OC=O bond in the molecular chain, respectively. The CO bond was the dominant characteristic peak, primarily originating from the hydroxyl and ether bonds in the CMC cellulose backbone. The presence of the OC=O bond further confirms the successful introduction of carboxyl and ester groups into the polymer chain.

[0087] In summary, the polar oxygen-containing functional groups such as hydroxyl, carboxyl, and ester groups enriched in the molecular chain of this terpolymer can undergo stable complexation and chelation with calcium and magnesium scale-forming ions in aqueous solution, effectively capturing scale-forming ions in water and inhibiting scale growth and aggregation. This is the core structural basis for the excellent scale inhibition and dispersing performance of the water treatment agent of this invention.

[0088] Comparative Example 1

[0089] A water treatment agent is polymerized from CMC, ESA, and hydroxyethyl acrylate in a mass ratio of 1:2:1, and the preparation steps are as follows:

[0090] S1. Add 10g of CMC to 400g of deionized water and stir at room temperature for 30 minutes to form a homogeneous viscous liquid.

[0091] S2. Nitrogen gas is introduced into the above CMC aqueous solution at a flow rate of 0.8 L / min for 30 min to remove dissolved oxygen from the system.

[0092] S3. Heat the system to 75°C and maintain constant temperature while stirring at a stirring rate of 250 r / min.

[0093] S4. Dissolve 20g ESA in 200ml of water, and then mix it with 10g hydroxyethyl acrylate to obtain a mixed monomer solution; dissolve 0.8g ammonium persulfate in 8ml of deionized water to obtain an ammonium persulfate solution; use a syringe pump to simultaneously and uniformly add the mixed monomer solution and ammonium persulfate solution to the S3 constant temperature system for 1 hour.

[0094] S5. After the addition is complete, heat the system to 85°C and keep it at that temperature for 3 hours.

[0095] S6. After cooling to room temperature, adjust the pH to 7.0 with 30% NaOH solution to obtain a pale yellow transparent liquid water treatment agent.

[0096] Performance test results: Calcium carbonate scale inhibition performance test: with a water treatment agent addition of 15 ppm, the calcium carbonate scale inhibition rate was 83.6%; calcium phosphate scale inhibition performance test: with a water treatment agent addition of 5 ppm, the calcium phosphate scale inhibition rate was 91.0%; iron oxide dispersion performance test: with a water treatment agent addition of 10 ppm, the iron oxide dispersion transmittance was 38.5%; carbon steel corrosion inhibition performance test: with a water treatment agent addition of 100 ppm, the carbon steel corrosion inhibition rate was 80.0%.

[0097] Comparative Example 2

[0098] A ternary copolymer water treatment agent is polymerized from CMC, acrylic acid, and HPA in a mass ratio of 1:2:1. The preparation steps are as follows:

[0099] S1. Add 10g of CMC to 400g of deionized water and stir at room temperature for 30 minutes to form a homogeneous viscous liquid.

[0100] S2. Nitrogen gas is introduced into the above CMC aqueous solution at a flow rate of 0.8 L / min for 30 min to remove dissolved oxygen from the system.

[0101] S3. Heat the system to 75°C and maintain constant temperature while stirring at a stirring rate of 250 r / min.

[0102] S4. Dissolve 20g of acrylic acid in 200ml of water, and then mix it with 10g of HPA to obtain a mixed monomer solution; dissolve 0.8g of ammonium persulfate in 8ml of deionized water to obtain an ammonium persulfate solution; use a syringe pump to simultaneously and uniformly add the mixed monomer solution and the ammonium persulfate solution to the S3 constant temperature system for 1 hour.

[0103] S5. After the addition is complete, heat the system to 85°C and keep it at that temperature for 3 hours.

[0104] S6. After cooling to room temperature, adjust the pH to 7.0 with 30% NaOH solution to obtain a colorless and transparent liquid water treatment agent.

[0105] Performance test results: Calcium carbonate scale inhibition performance test: with a water treatment agent addition of 15 ppm, the calcium carbonate scale inhibition rate was 85.0%; calcium phosphate scale inhibition performance test: with a water treatment agent addition of 5 ppm, the calcium phosphate scale inhibition rate was 93.7%; iron oxide dispersion performance test: with a water treatment agent addition of 10 ppm, the iron oxide dispersion transmittance was 45.0%; carbon steel corrosion inhibition performance test: with a water treatment agent addition of 100 ppm, the carbon steel corrosion inhibition rate was 79.8%.

[0106] Comparative Example 3

[0107] A ternary copolymer water treatment agent is polymerized from CMC, ESA, and HPA in a mass ratio of 1:2:1. The preparation steps are as follows:

[0108] S1. Add 10g of CMC to 400g of deionized water and stir at room temperature for 30 minutes to form a homogeneous viscous liquid.

[0109] S2. Nitrogen gas is introduced into the above CMC aqueous solution at a flow rate of 0.8 L / min for 30 min to remove dissolved oxygen from the system.

[0110] S3. Add 1.2g of tert-butanol to the system, heat the system to 75℃, and keep the temperature constant while stirring at a stirring rate of 250r / min.

[0111] S4. Dissolve 20g ESA in 200ml of water, and then mix it with 10g HPA to obtain a mixed monomer solution. Dissolve 0.8g ammonium persulfate in 8ml of deionized water to obtain an ammonium persulfate solution. Use a syringe pump to simultaneously and uniformly add the mixed monomer solution and the ammonium persulfate solution to the S3 constant temperature system for 1 hour.

[0112] S5. After the addition is complete, heat the system to 85°C and keep it at that temperature for 3 hours.

[0113] S6. After cooling to room temperature, adjust the pH to 7.0 with 30% NaOH solution to obtain a pale yellow transparent liquid water treatment agent.

[0114] Performance test results: Calcium carbonate scale inhibition performance test: with a water treatment agent addition of 10 ppm, the calcium carbonate scale inhibition rate was 81.7%; calcium phosphate scale inhibition performance test: with a water treatment agent addition of 5 ppm, the calcium phosphate scale inhibition rate was 87.5%; iron oxide dispersion performance test: with a water treatment agent addition of 10 ppm, the iron oxide dispersion transmittance was 38.6%; carbon steel corrosion inhibition performance test: with a water treatment agent addition of 100 ppm, the carbon steel corrosion inhibition rate was 69.8%.

[0115] Comparative Example 4

[0116] A ternary copolymer water treatment agent is polymerized from CMC, ESA, and HPA in a mass ratio of 1:2:1. The preparation steps are as follows:

[0117] S1. Add 10g of CMC to 400g of deionized water and stir at room temperature for 30 minutes to form a homogeneous viscous liquid.

[0118] S2. Nitrogen gas is introduced into the above CMC aqueous solution at a flow rate of 0.8 L / min for 30 min to remove dissolved oxygen from the system.

[0119] S3. Add 1.2g of isopropanol to the system, heat the system to 75℃, and keep the temperature constant while stirring at a stirring rate of 250r / min.

[0120] S4. Dissolve 20g ESA in 200ml of water, and then mix it with 10g HPA to obtain a mixed monomer solution. Dissolve 0.8g ammonium persulfate in 8ml of deionized water to obtain an ammonium persulfate solution. Use a syringe pump to simultaneously and uniformly add the mixed monomer solution and the ammonium persulfate solution to the S3 constant temperature system for 1 hour.

[0121] S5. After the addition is complete, heat the system to 85°C and keep it at that temperature for 3 hours.

[0122] S6. After cooling to room temperature, adjust the pH to 7.0 with 30% NaOH solution to obtain a pale yellow transparent liquid water treatment agent.

[0123] Performance test results: Calcium carbonate scale inhibition performance test: with a water treatment agent addition of 10 ppm, the calcium carbonate scale inhibition rate was 80.9%; calcium phosphate scale inhibition performance test: with a water treatment agent addition of 5 ppm, the calcium phosphate scale inhibition rate was 89.3%; iron oxide dispersion performance test: with a water treatment agent addition of 10 ppm, the iron oxide dispersion transmittance was 39.2%; carbon steel corrosion inhibition performance test: with a water treatment agent addition of 100 ppm, the carbon steel corrosion inhibition rate was 71.3%.

[0124] Comparative Example 5

[0125] A ternary copolymer water treatment agent is polymerized from CMC, ESA, and HPA in a mass ratio of 1:2:1. The preparation steps are as follows:

[0126] S1. Add 10g of CMC to 400g of deionized water and stir at room temperature for 30 minutes to form a homogeneous viscous liquid.

[0127] S2. Nitrogen gas is introduced into the above CMC aqueous solution at a flow rate of 0.8 L / min for 30 min to remove dissolved oxygen from the system.

[0128] S3. Add 1.2g of tert-butanol to the system, heat the system to 75℃, and keep the temperature constant while stirring at a stirring rate of 250r / min.

[0129] S4. Dissolve 20g ESA in 200ml of water, and then mix it with 10g HPA to obtain a mixed monomer solution. Dissolve 0.8g cerium ammonium nitrate in 4g 0.5mol / L dilute nitric acid to obtain a cerium ammonium nitrate solution. Use a syringe pump to simultaneously and uniformly add the mixed monomer solution and the cerium ammonium nitrate solution to the S3 constant temperature system for 1 hour.

[0130] S5. After the addition is complete, heat the system to 85°C and keep it at that temperature for 3 hours.

[0131] S6. After cooling to room temperature, adjust the pH to 7.0 with 30% NaOH solution to obtain a colorless and transparent liquid water treatment agent.

[0132] Performance test results: Calcium carbonate scale inhibition performance test: with a water treatment agent addition of 10 ppm, the calcium carbonate scale inhibition rate was 73.1%; Calcium phosphate scale inhibition performance test: with a water treatment agent addition of 5 ppm, the calcium phosphate scale inhibition rate was 70.5%; Iron oxide dispersion performance test: with a water treatment agent addition of 10 ppm, the iron oxide dispersion transmittance was 52.8%; Carbon steel corrosion inhibition performance test: with a water treatment agent addition of 100 ppm, the carbon steel corrosion inhibition rate was 63.7%.

[0133] Based on the preparation process and performance test results of the above embodiments and comparative examples, it can be seen that the present invention uses CMC, ESA, and HPA as monomers for ternary copolymerization to prepare a phosphorus-free and nitrogen-free green water treatment agent. The preparation process is stable, and the resulting product exhibits good overall performance. In the comparative examples, changing the functional monomers, adding additives, or replacing the initiator all led to varying degrees of decrease in the scale inhibition and corrosion inhibition performance of the agent, indicating that the monomer combination, additive-free technical solution, and suitable initiation system adopted in this invention have technical advantages. Combined with structural characterization results, this ternary copolymer successfully introduces active functional groups such as ester and carboxyl groups while retaining the original molecular skeleton of CMC. Through the synergistic effect of multiple functional groups, it achieves scale inhibition, dispersion, and corrosion inhibition water treatment effects. This water treatment agent is environmentally friendly and low-consumption, with balanced performance across various aspects. It can replace traditional phosphorus-based water treatment agents, reducing eutrophication problems caused by phosphorus-containing wastewater at the source. It is suitable for industrial circulating water, wastewater treatment, and other fields, and has good practical application value.

[0134] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A ternary copolymer water treatment agent, characterized in that, The water treatment agent is prepared by aqueous phase free radical copolymerization of three monomers: sodium carboxymethyl cellulose, epoxy succinic acid, and hydroxypropyl acrylate; the mass ratio of sodium carboxymethyl cellulose, epoxy succinic acid, and hydroxypropyl acrylate is 1:1 to 3.5:1 to 2 by mass.

2. The ternary copolymer water treatment agent according to claim 1, characterized in that, The mass ratio of sodium carboxymethyl cellulose, epoxy succinic acid, and hydroxypropyl acrylate is 1:2:

1.

3. A method for preparing the ternary copolymer water treatment agent as described in claim 1 or 2, characterized in that, It includes the following steps: S1. Dissolving: Add sodium carboxymethyl cellulose to deionized water and stir at room temperature until completely dissolved to obtain a homogeneous viscous liquid; S2, Deoxygenation: Nitrogen gas is introduced into the solution obtained in step S1 at a flow rate of 0.5 to 1.0 L / min for 30 to 40 min to completely remove dissolved oxygen from the system. S3. Preheating: Heat the system obtained in step S2 to 60-80°C and keep it at a constant temperature while stirring. S4. Adding copolymerization: First, dissolve epoxy succinic acid in water to obtain an epoxy succinic acid solution, then mix it evenly with hydroxypropyl acrylate to obtain a mixed monomer solution; dissolve ammonium persulfate in deionized water to obtain an ammonium persulfate solution; simultaneously and uniformly add the mixed monomer solution and the ammonium persulfate solution to the system obtained in step S3, and control the adding time to be 0.5-2h. S5. Heat preservation: After the addition is complete, heat the system to 80-90℃ and keep it at this temperature for 3-5 hours. S6. Post-treatment: Cool the reaction system to room temperature and adjust the pH to 6.5-7.5 with an alkaline solution to obtain the ternary copolymer water treatment agent.

4. The preparation method of the ternary copolymer water treatment agent according to claim 3, characterized in that, In step S1, the mass ratio of sodium carboxymethyl cellulose to deionized water is 2-3:

100.

5. The preparation method of the ternary copolymer water treatment agent according to claim 3, characterized in that, In step S4, the amount of ammonium persulfate used is 1% to 3% of the total mass of the three monomers.

6. The preparation method of the ternary copolymer water treatment agent according to claim 3, characterized in that, In step S4, the concentration of the ammonium persulfate solution is 8-15%.

7. The preparation method of the ternary copolymer water treatment agent according to claim 3, characterized in that, In step S4, the concentration of the epoxy succinic acid is 8-15%.

8. The preparation method of the ternary copolymer water treatment agent according to claim 3, characterized in that, In step S6, the alkaline solution is a 30% sodium hydroxide solution.

9. The application of a ternary copolymer water treatment agent as described in claim 1 or 2 in industrial water treatment.

10. The application according to claim 9, characterized in that, The ternary copolymer water treatment agent is directly added to industrial water at a dosage of 5–100 mg / L.

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