Dendrimer containing polyoxyethylene structure and method for preparing same, non-phosphorus corrosion and scale inhibitor and use thereof

Abstract

The application discloses a dendrimer containing a polyoxyethylene structure and a preparation method thereof, a phosphorus-free corrosion and scale inhibitor and application thereof, and a structural general formula of the dendrimer is as follows: wherein a structural general formula of R is as follows: m is an integer of 1-100, n is a natural number, a polymerization degree x is 1-5000, and a polymerization degree y is 1-5000. The dendrimer containing the polyoxyethylene structure has good scale inhibition performance, and simultaneously has the functions of cleaning and defoaming, is biodegradable, and can be used as an environmentally-friendly multifunctional phosphorus-free scale inhibitor. In the application, the polyoxyethylene structure is introduced, has a solubilization effect, that is, is beneficial to improving the solubility of the polymer in water, and thus improves the scale inhibition effect.

Description

Technical Field

[0001] This invention relates to the field of polymer preparation and application, specifically to a dendritic polymer containing a polyoxyethylene structure and its preparation method, and a phosphorus-free corrosion and scale inhibitor and its application. Background Technology

[0002] Scaling is a significant challenge faced by many industrial water systems (such as circulating cooling water systems, membrane treatment devices, and oil and gas field water reinjection systems) during actual operation. Currently, adding chemical scale inhibitors is a commonly used method. These inhibitors can effectively inhibit the nucleation and growth of scale crystals (such as calcium carbonate and calcium sulfate), thereby delaying or preventing scale adhesion to metal surfaces.

[0003] Polyphosphates are the most widely used scale inhibitors, with common examples including sodium tripolyphosphate and sodium hexametaphosphate. These scale inhibitors have excellent scale inhibition effects, but their drawback is hydrolysis. Hydrolysis not only reduces their scale inhibition performance, but the resulting phosphate ions combine with calcium ions to produce calcium phosphate precipitates with low solubility. Furthermore, with increasingly stringent environmental policies, phosphate-free water systems in various industries have become an inevitable trend and requirement, further shrinking the market space for phosphorus-based water treatment agents.

[0004] In recent years, phosphorus-free chemical systems have also developed rapidly. Currently, carboxylic acid polymers, represented by polyepoxysuccinic acid and polyaspartic acid, have been widely used. Furthermore, CN100575391A discloses an epoxysuccinic acid / p-epoxyethylbenzenesulfonic acid copolymer scale inhibitor, CN101899134A discloses a phosphorus-free polyether scale inhibitor prepared by a one-step esterification reaction using lactone, and CN102910745A discloses a fluorescently traced, environmentally friendly polyethylene glycol-based water treatment agent.

[0005] Overall, the types and quantities of available phosphorus-free chemical systems are still relatively small, and there are still certain shortcomings in practical applications, such as low calcium tolerance, unsatisfactory performance under high temperature conditions, poor compatibility with some water qualities, and rapid decline in scale inhibition rate over time. Summary of the Invention

[0006] The purpose of this invention is to provide dendritic polymers containing polyoxyethylene structures and their preparation methods, as well as phosphorus-free corrosion and scale inhibitors and their applications, in order to solve the problems that the types and quantities of existing phosphorus-free agent systems are still relatively small and that the scale inhibition rate of existing phosphorus-free corrosion and scale inhibitors decreases rapidly over time.

[0007] In a first aspect, the present invention provides a dendritic polymer containing a polyoxyethylene structure, the general structural formula of which is as follows:

[0008]

[0009] Where: the general structural formula of R is:

[0010]

[0011] The number of repeating units m is an integer from 1 to 100, n is a natural number, the degree of aggregation x is 1-5000, and the degree of aggregation y is 1-5000.

[0012] The beneficial effects of this invention are as follows: The dendritic polymer containing a polyoxyethylene structure disclosed in this invention is rich in carboxylic acid and sulfonic acid groups and contains no phosphorus. Therefore, this dendritic polymer containing a polyoxyethylene structure has excellent scale inhibition properties, while also possessing cleaning and defoaming functions. It is biodegradable and can be used as an environmentally friendly, multifunctional, phosphorus-free scale inhibitor. The introduction of the polyoxyethylene structure in this invention has a solubilizing effect, which improves the polymer's solubility in water, thereby enhancing the scale inhibition effect. The scale inhibition rate of the dendritic polymer containing a polyoxyethylene structure provided by this invention decreases slowly with prolonged use, thus exhibiting a long service life.

[0013] In a second aspect, the present invention provides a method for preparing the above-mentioned dendritic polymer containing a polyoxyethylene structure, comprising the following steps: subjecting a polyamine compound to an epoxy addition reaction to obtain a dendritic nitrogen-containing polyether monomer containing a polyoxyethylene structure;

[0014] After modifying the dendritic nitrogen-containing polyether monomer with unsaturated groups, a modified dendritic nitrogen-containing polyether monomer is obtained.

[0015] The modified dendritic nitrogen-containing polyether monomer undergoes a free radical copolymerization reaction with unsaturated organic acids, unsaturated sulfonic acids, or unsaturated sulfonates in the presence of an initiator.

[0016] The beneficial effects of this invention are: the preparation method is simple, the reaction process is easy to control, and the mass fraction of the target product is high, making it suitable for widespread application.

[0017] Thirdly, the present invention provides a phosphorus-free corrosion and scale inhibitor based on the above-mentioned dendritic polymer containing a polyoxyethylene structure, comprising the following components in parts by weight:

[0018] 0.1 to 15 parts of the above-mentioned dendritic polymer containing a polyoxyethylene structure

[0019] 0.1 to 10 parts of polyepoxysuccinic acid or polyepoxysuccinate

[0020] 0.1 to 5 parts gluconate

[0021] Inorganic zinc salt 0.1–5 parts

[0022] Citric acid 0.1-5 parts

[0023] Solvent: 60–99.5 parts.

[0024] The beneficial effects of this invention are: it can effectively reduce the dosage of other components without affecting the treatment effect, and the components synergistically enhance the corrosion and scale inhibition effect, especially extending the effective scale inhibition time of the scale inhibitor and reducing the cost of corrosion and scale inhibition; it is worth promoting its use in industrial water systems. Attached Figure Description

[0025] Figure 1 The graphs show the scale inhibition performance test results of the dendritic polymers obtained in Examples 1-4. Detailed Implementation

[0026] To make the technical problems to be solved, the technical solutions, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0027] Polyphosphates are prone to hydrolysis, which not only reduces their scale inhibition performance but also produces phosphate ions that combine with calcium ions to form calcium phosphate precipitates with low solubility. Furthermore, with increasingly stringent environmental policies, the elimination of phosphates in water systems across various industries has become an inevitable trend and requirement, further shrinking the market space for phosphorus-based water treatment agents. Currently, the types and quantities of available phosphorus-free agents remain limited, and they still have certain shortcomings in practical applications, such as low calcium tolerance, unsatisfactory performance at high temperatures, and poor compatibility with certain water qualities.

[0028] The inventors of this invention introduce a polyoxyethylene structure onto a polyamine compound as an initiator to provide solubility in water, and introduce carboxylic acid and sulfonic acid groups through free radical copolymerization to inhibit scale formation; thus achieving scale inhibition while reducing the amount of scale inhibitor used and achieving phosphate-free treatment.

[0029] This invention discloses a dendritic polymer containing a polyoxyethylene structure, the general structural formula of which is as follows:

[0030]

[0031] Where: the general structural formula of R is:

[0032]

[0033] The number of repeating units m is an integer from 1 to 100, n is a natural number, the degree of aggregation x is 1-5000, and the degree of aggregation y is 1-5000.

[0034] This invention discloses a method for preparing the above-mentioned dendritic polymer containing a polyoxyethylene structure, comprising the following steps:

[0035] S1. The polyamine compound is subjected to an epoxy addition reaction to obtain a dendritic nitrogen-containing polyether monomer with a polyoxyethylene structure;

[0036] In this invention, the polyamine compound includes, but is not limited to, ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, or polyene polyamine.

[0037] In this invention, epoxides can be used to perform an epoxide addition reaction on the polyamine compound.

[0038] For example

[0039] Using potassium hydroxide as a catalyst and ethylene oxide as an adduct, the reaction was carried out under nitrogen protection at a controlled temperature of 135℃ and a pressure of 0.3 MPa. After 1-5 hours of reaction, a certain amount of distilled water was added, and acetic acid was added dropwise to neutralize the potassium hydroxide catalyst. Insoluble impurities were removed by filtration through a filter membrane, followed by extraction with dichloromethane. The dichloromethane was then removed by evaporation, and finally dried at about 60℃.

[0040] m = 1 to 20, which can be controlled according to needs and is not specifically limited.

[0041] (a) Addition reaction of ethylenediamine with ethylene oxide

[0042]

[0043] (b) Addition reaction of diethylenetriamine with ethylene oxide

[0044]

[0045] (c) Addition reaction of triethylenetetramine with ethylene oxide

[0046]

[0047] (d) Addition reaction of tetraethylenepentamine with ethylene oxide

[0048]

[0049] By selecting different amines as initiators and utilizing the grafting properties of amino groups, polyether macromonomers with varying degrees of branching were synthesized. Simultaneously, these macromonomers possess abundant polyoxyethylene (EO) structures, which, while ensuring water solubility, also provide certain cleaning and defoaming effects.

[0050] S2. After modifying the dendritic nitrogen-containing polyether monomer with unsaturated groups, a modified dendritic nitrogen-containing polyether monomer is obtained;

[0051] In this invention, unsaturated organic carboxylic acids can be used to modify the dendritic nitrogen-containing polyether monomer with unsaturated groups. The molecular structure of the unsaturated organic carboxylic acid contains both unsaturated carbon-carbon double bonds and carboxylic acid groups.

[0052] Common examples include acrylic acid, methacrylic acid, maleic acid (anhydride), itaconic acid, and fumaric acid. They have the following general formula:

[0053] in

[0054] Wherein: the number of repeating units m is 1 to 10.

[0055] For example

[0056] Taking ethylenediamine as an initiator and itaconic acid esterification reaction as an example

[0057] Compounds ethylenediamine and itaconic acid, in a molar ratio of 1:1.0–5.0, were esterified at 60–80°C for 1–5 hours under anhydrous, nitrogen-protected, and stirred conditions to obtain unsaturated carboxylic acid-modified polyether macromonomers.

[0058]

[0059] Grafting unsaturated small monomers containing carboxyl groups onto polyether macromonomers introduces unsaturated double bonds while introducing certain carboxyl groups, which are then used for the next polymerization reaction.

[0060] S3. Modified dendritic nitrogen-containing polyether monomers are simultaneously subjected to free radical copolymerization with unsaturated organic acids, unsaturated sulfonic acids, or unsaturated sulfonates in the presence of an initiator. This achieves the synthesis of polymers containing carboxyl, sulfonic acid, and EO groups simultaneously.

[0061] In this invention, the unsaturated organic acid and the aforementioned unsaturated organic carboxylic acid can be of the same or different types. The unsaturated organic acid includes, but is not limited to, at least one of acrylic acid, methacrylic acid, maleic acid (anhydride), itaconic acid, and fumaric acid.

[0062] In this invention, the unsaturated sulfonic acid or unsaturated sulfonate molecule contains both an unsaturated carbon-carbon double bond and a sulfonic acid group. Examples include 2-acrylamido-2-methylpropanesulfonic acid (AMPS), propanesulfonic acid, styrenesulfonic acid, sodium methpropylene sulfonate, and sodium vinyl sulfonate. They possess the following general formula:

[0063] Or H2C = CH-R3-SO3Na

[0064] in:

[0065]

[0066] The number of repeating units n = 1 to 10

[0067] R4=H,-CH3

[0068] In this invention, the initiator is a substance that can induce monomeric compounds to undergo polymerization reactions, such as ammonium persulfate, potassium persulfate, sodium superphosphate, hydrogen peroxide, azobisisobutyronitrile, tert-butyl peroxide, diacyl peroxide, etc.

[0069] The initiator includes, but is not limited to, at least one of ammonium persulfate, potassium persulfate, sodium superphosphate, hydrogen peroxide, azobisisobutyronitrile, tert-butyl peroxide, and diacyl peroxide.

[0070] For example

[0071] Taking the further polymerization reaction of modified dendritic nitrogen-containing polyether monomers with 2-acrylamide-2-methylpropanesulfonic acid (AMPS) and itaconic acid as an example.

[0072] AMPS, itaconic acid, and the unsaturated carboxylic acid-modified polyether macromonomer obtained in the previous step undergo a free radical copolymerization reaction under nitrogen protection and with the aid of an initiator.

[0073] First, weigh out a certain amount of compounds AMPS and itaconic acid and place them in a flask. Add a certain amount of distilled water, stir at room temperature until fully dissolved, and then heat to around 70°C.

[0074] Next, the unsaturated carboxylic acid-modified polyether macromonomer is dissolved in a certain amount of distilled water and then transferred to a constant-pressure dropping funnel. A certain amount of initiator is dissolved in a certain amount of distilled water and then transferred to another constant-pressure dropping funnel.

[0075] Finally, maintaining the temperature in the flask at 70°C, the solution in both constant-pressure dropping funnels is simultaneously added dropwise over a period of approximately 30 minutes to 2 hours. After the addition is complete, the temperature is raised to 75–95°C, and the reaction is continued at this temperature for 1–5 hours. This yields an aqueous solution of a dendritic polymer containing a polyoxyethylene structure, with a mass fraction of 5–40 wt%.

[0076] It should be noted that in this aqueous free radical polymerization reaction, the proportions of each monomer and the amount of initiator can be adjusted according to actual needs. Polymers with different unit ratios can usually be synthesized by adjusting the monomer proportions, while the control of the initiator amount and polymerization reaction time can be used to synthesize dendritic polymers containing polyoxyethylene structures with different degrees of polymerization (molecular weight).

[0077] In addition, it should be noted that the above examples involve two monomers undergoing ternary polymerization with modified polyether macromonomers. In practice, the type and quantity of monomers used can be controlled as needed.

[0078] Example

[0079] Example 1

[0080] The preparation of a dendritic polymer containing a polyoxyethylene structure includes the following steps:

[0081] S1. Using potassium hydroxide as a catalyst, under nitrogen protection and with the temperature and pressure controlled at 135℃ and 0.3 MPa, 0.1 mol ethylenediamine and 0.8 mol ethylene oxide reacted for 1-5 hours. Then, 50 g of distilled water was added, and acetic acid was added dropwise to neutralize the potassium hydroxide catalyst. Insoluble impurities were removed by filtration through a membrane, followed by extraction with dichloromethane. The dichloromethane was then removed by evaporation, and finally dried at approximately 60℃ to obtain branched nitrogen-containing polyether macromonomers.

[0082] S2. Weigh 0.05 mol of the nitrogen-containing polyether macromonomer prepared in step S1 and 0.24 mol of maleic anhydride into a flask. Stir at room temperature for 1 hour under nitrogen protection, then raise the temperature to 70°C and continue stirring for 3 hours.

[0083] S3. Weigh out 0.2 mol itaconic acid and 0.2 mol AMPS respectively, dissolve them in 100 g of deionized water, and place them in a flask.

[0084] S4. Dissolve the polyether macromonomer obtained in step S2 in 50g of deionized water and then transfer it to a constant pressure dropping funnel; weigh 2wt% of the total amount of polyether macromonomer initiator potassium persulfate and dissolve it in 50g of deionized water, then transfer it to another constant pressure dropping funnel.

[0085] S5. Under controlled temperature of 70℃, add the material dropwise to the flask (continuously for about 1 hour). After the addition is complete, raise the temperature to 80℃ and continue the polymerization reaction at this temperature for 2 hours. Then, stop heating and stirring, and cool to room temperature. An aqueous solution of a dendritic polymer containing a polyoxyethylene structure is obtained.

[0086] Example 2

[0087] The preparation of a dendritic polymer containing a polyoxyethylene structure includes the following steps:

[0088] S1. Using potassium hydroxide as a catalyst, under nitrogen protection, the temperature and pressure were controlled at 135℃ and 0.3 MPa, respectively. 0.1 mol of diethylenetriamine and 1 mol of ethylene oxide were reacted for 1-5 hours. After the reaction, 80 g of distilled water was added, and acetic acid was added dropwise to neutralize the potassium hydroxide catalyst. Insoluble impurities were removed by filtration through a filter membrane, followed by extraction with dichloromethane. The dichloromethane was then removed by evaporation, and finally dried at approximately 60℃ to obtain a branched nitrogen-containing polyether macromonomer.

[0089] S2. Weigh 0.05 mol of the nitrogen-containing polyether macromonomer prepared in step S1 and 0.25 mol of itaconic acid into a flask. Stir at room temperature for 1 hour under nitrogen protection, then raise the temperature to 70°C and continue stirring for 3 hours.

[0090] S3. Weigh out 0.1 mol itaconic acid and 0.3 mol sodium methyl propylene sulfonate, dissolve them in 100 g of deionized water, and place them in a flask.

[0091] S4. Dissolve the polyether macromonomer obtained in step 2 in 100g of deionized water and then transfer it to a constant pressure dropping funnel; weigh 3wt% of the total amount of polyether macromonomer initiator tert-butyl peroxide and dissolve it in 50g of deionized water, then transfer it to another constant pressure dropping funnel.

[0092] S5. Under controlled temperature of 70℃, add the material dropwise to the flask (continuously for about 1 hour). After the addition is complete, raise the temperature to 80℃ and continue the polymerization reaction at this temperature for 3 hours. Then, stop heating and stirring, and cool to room temperature. An aqueous solution of a dendritic polymer containing a polyoxyethylene structure is obtained.

[0093] Example 3

[0094] The preparation of a dendritic polymer containing a polyoxyethylene structure includes the following steps:

[0095] S1. Using potassium hydroxide as a catalyst, under nitrogen protection, the temperature and pressure were controlled at 135℃ and 0.3 MPa, respectively. 0.1 mol of triethylenetetramine and 1.2 mol of ethylene oxide were reacted for 1-5 hours. After the reaction, 100 g of distilled water was added, and acetic acid was added dropwise to neutralize the potassium hydroxide catalyst. Insoluble impurities were removed by filtration through a filter membrane, followed by extraction with dichloromethane. The dichloromethane was then removed by evaporation, and finally dried at approximately 60℃ to obtain a branched nitrogen-containing polyether macromonomer.

[0096] S2. Weigh 0.05 mol of the nitrogen-containing polyether macromonomer prepared in step S1 and 0.3 mol of fumaric acid into a flask. Stir at room temperature for 1 hour under nitrogen protection, then raise the temperature to 75°C and continue stirring for 2.5 hours.

[0097] S3. Weigh out 0.3 mol of acrylic acid and 0.3 mol of sodium vinyl sulfonate, dissolve them in 200 g of deionized water, and place them in a flask.

[0098] S4. Dissolve the polyether macromonomer obtained in step 2 in 50g of deionized water and then transfer it to a constant pressure dropping funnel; weigh 2wt% of the total amount of monomers of the initiator potassium persulfate, dissolve it in 50g of deionized water, and then transfer it to another constant pressure dropping funnel.

[0099] S5. Under controlled temperature of 70℃, add the material dropwise to the flask (continuously for about 1 hour). After the addition is complete, raise the temperature to 80℃ and continue the polymerization reaction at this temperature for 3 hours. Then, stop heating and stirring, and cool to room temperature. An aqueous solution of a dendritic polymer containing a polyoxyethylene structure is obtained.

[0100] Example 4

[0101] The preparation of a dendritic polymer containing a polyoxyethylene structure includes the following steps:

[0102] S1. Using potassium hydroxide as a catalyst, under nitrogen protection, the temperature and pressure were controlled at 135℃ and 0.3 MPa, respectively. 0.1 mol of tetraethylenepentamine and 1.4 mol of ethylene oxide were reacted for 1-5 hours. After the reaction, 120 g of distilled water was added, and acetic acid was added dropwise to neutralize the potassium hydroxide catalyst. Insoluble impurities were removed by filtration through a filter membrane, followed by extraction with dichloromethane. The dichloromethane was then removed by evaporation, and finally dried at approximately 60℃ to obtain a branched nitrogen-containing polyether macromonomer.

[0103] S2. Weigh 0.05 mol of the nitrogen-containing polyether macromonomer prepared in step S1 and 0.35 mol of acrylic acid into a flask. Stir at room temperature for 1 hour under nitrogen protection, then heat to 75°C and continue stirring for 4 hours.

[0104] S3. Weigh out 0.3 mol of methacrylic acid and 0.3 mol of acrylamide sulfonic acid, dissolve them in 200 g of deionized water, and place them in a flask.

[0105] S4. Dissolve the polyether macromonomer obtained in step 2 in 50g of deionized water and then transfer it to a constant pressure dropping funnel; weigh 2wt% of the total amount of monomers of the initiator azobisisobutyronitrile and dissolve it in 50g of deionized water, then transfer it to another constant pressure dropping funnel.

[0106] S5. Under controlled temperature of 70℃, add the material dropwise to the flask (continuously for about 2 hours). After the addition is complete, raise the temperature to 80℃ and continue the polymerization reaction at this temperature for 3 hours. Then stop heating and stirring, and cool to room temperature. An aqueous solution of a dendritic polymer containing a polyoxyethylene structure is obtained.

[0107] Example 5

[0108] This embodiment uses the dendritic polymer containing a polyoxyethylene structure obtained in Example 1 as an example to formulate a phosphorus-free corrosion and scale inhibitor.

[0109] Five parts by weight of a dendritic polymer containing a polyoxyethylene structure, five parts of polyepoxysuccinic acid, two parts of sodium gluconate, two parts of zinc sulfate, two parts of citric acid, and eighty-four parts of water were placed in a container and mixed evenly to obtain a phosphorus-free corrosion and scale inhibitor.

[0110] Example 6

[0111] This embodiment uses the dendritic polymer containing a polyoxyethylene structure obtained in Example 2 as an example to formulate a phosphorus-free corrosion and scale inhibitor.

[0112] Eight parts by weight of a dendritic polymer containing a polyoxyethylene structure, two parts of polyepoxysuccinic acid, three parts of sodium gluconate, three parts of zinc sulfate, three parts of citric acid, and 79 parts of water were placed in a container and mixed evenly to obtain a phosphorus-free corrosion and scale inhibitor.

[0113] Example 7

[0114] This embodiment uses the dendritic polymer containing a polyoxyethylene structure obtained in Example 3 as an example to formulate a phosphorus-free corrosion and scale inhibitor.

[0115] Ten parts by weight of a dendritic polymer containing a polyoxyethylene structure, two parts of polyepoxysuccinic acid, one part of sodium gluconate, four parts of zinc sulfate, two parts of citric acid, and eighty-one parts of water were placed in a container and mixed evenly to obtain a phosphorus-free corrosion and scale inhibitor.

[0116] Experimental Example 1

[0117] The test method followed GB / T18175-2014 "Determination of Corrosion Inhibition Performance of Water Treatment Agents", and an RCC-Ⅱ type rotating plate corrosion tester was used for evaluation. The test temperature was controlled at 45℃, the plate rotation speed at 75 rpm, and the equipment was naturally exposed to air (without other continuous ventilation devices). The test cycle was 72 hours. The corrosion test was conducted in a 2L beaker with two test pieces installed simultaneously, and the average value of the results was taken.

[0118] A simulated corrosion solution with a calcium hardness of approximately 100 mg / L was prepared for corrosion evaluation, and a scale inhibitor concentration of 60 ppm was added.

[0119] Table 1. Measurement of corrosion rate

[0120] / Corrosion rate (mm / a) blank 0.587 Example 5 0.0083 Example 6 0.0049 Example 7 0.0102

[0121] As shown in Table 1, the phosphorus-free corrosion and scale inhibitor prepared by this invention has good corrosion inhibition performance.

[0122] Experimental Example 2

[0123] The test method was in accordance with GB / T16632-2008 "Determination of Scale Inhibition Performance of Water Treatment Agents". The static scale inhibition method was used for evaluation, and the calcium ion content was determined by EDTA titration. The experimental temperature was controlled at 80℃ in a water bath for 10 hours.

[0124] Prepare a simulated water with a calcium hardness of approximately 600 mg / L to evaluate the scale inhibition rate, and add a scale inhibitor at a concentration of 60 ppm.

[0125] Table 2 Evaluation of Scale Inhibition Rate

[0126] / Scale inhibition rate % Example 5 98.6 Example 6 97.8 Example 7 98.3

[0127] As shown in Table 2, the phosphorus-free corrosion and scale inhibitor prepared by this invention has good scale inhibition performance, reaching over 97%.

[0128] Application Example 1

[0129] The polymers prepared in Examples 1-4 of this invention contain hydrophilic carboxyl groups, polyoxyethylene chains, and hydrophobic alkyl chains, giving the compounds a certain degree of peeling and cleaning function against biological slime and grease. The cleaning performance of the polymers prepared in Examples 1-4 of this invention was tested, and the specific steps are as follows:

[0130] Step 101: First, obtain a 20# carbon steel metal test piece as the test object. Its size is 30×15×3mm. Polish it with 220-grit sandpaper, clean and dry it, and weigh it as m1. Then place the test piece in a clean glass container and weigh the sum of the mass of the test piece and the clean glass container as m2.

[0131] Step 102: Coat the test piece with rust-preventive oil, the amount of which should be such that it does not drip after hanging for 60 seconds. Then place it in a glass container and weigh it to m3. Further add the polymer and deionized water to the glass container (the concentration of the polymer in the water should be controlled at 200 ppm). After soaking at 35°C for 10 minutes, place the glass container on a rotary shaker and shake for 5 minutes.

[0132] Step 103: Remove the sample, hang it to dry at room temperature for 10 minutes, weigh it (m4), and calculate the cleaning ability η of the polymer according to the following formula:

[0133]

[0134] Where m1, m2, m3, and m4 are all in g, and η is in %.

[0135] The cleaning efficiency of the polymers prepared in Examples 1-4 was tested using the above method, and the specific test results are shown in Table 3.

[0136] Table 3 shows the cleaning efficiency results of the polymers prepared in Examples 1-4.

[0137] / Cleaning efficiency / % Example 1 84.7 Example 2 81.2 Example 3 85.4 Example 4 83.5

[0138] As shown in Table 3, the dendritic polymer containing polyoxyethylene structure prepared by this invention has good cleaning efficiency, reaching over 80%, and can be used as a cleaning agent.

[0139] Application Example 2

[0140] Due to the presence of microorganisms, a certain amount of quaternary ammonium salt is often used as a bactericide and algaecide during the daily operation of circulating water systems. Quaternary ammonium salt has a strong foaming ability, which often leads to foaming in circulating water, especially immediately after the addition of quaternary ammonium salt. This foaming is detrimental to the normal operation of systems such as water pumps. The polymer of this invention contains a polyoxyethylene structure within its unique branched structure. After being adsorbed onto the air-water interface, the polymer effectively reduces the interfacial strength of the air-water interface, thereby achieving a defoaming effect and possessing a certain foam-suppressing function. The defoaming performance of the polymers prepared in Examples 1-4 of this invention was tested, specifically as follows:

[0141] Using dodecyl dimethyl benzyl ammonium chloride (DDBAC) as the test material, simulated water with a calcium hardness and alkalinity of 500 mg / L was used as the test water quality. A 200 ppm DDBAC aqueous solution was prepared for the blank group; a mixed solution with 200 ppm DDBAC and 200 ppm polymer concentration was prepared for the experimental group. A high-speed stirrer was used at 10,000 rpm for 2 minutes to simulate foam, and the foam was immediately poured into a 1000 ml graduated cylinder to measure the foam volume. Specific test results are shown in Table 4.

[0142] Table 4 shows the test results of the defoaming properties of the polymers prepared in Examples 1-4.

[0143]

[0144]

[0145] As can be seen from Table 4, the dendritic polymers prepared in Examples 1 to 4 of the present invention have good defoaming properties and can be used as defoamers to a certain extent.

[0146] Application Example 3

[0147] The test methods were in accordance with GB / T16632-2008 "Determination of Scale Inhibition Performance of Water Treatment Agents". The static scale inhibition method was used for evaluation, and the calcium ion content was determined by EDTA titration. Unless otherwise specified, all experimental temperatures were controlled at 80℃ using a water bath.

[0148] Prepare a simulated water with a calcium hardness of approximately 600 mg / L to evaluate the scale inhibition rate, and add a scale inhibitor at a concentration of 60 ppm.

[0149] Polyepoxysuccinic acid (PESA) and polyaspartic acid (PASP) were used as comparative examples.

[0150] The scale inhibition results of dendritic polymers, PESA, and PASP obtained in Examples 1-4 are as follows: Figure 1 As shown, by Figure 1 It can be seen that the scale inhibition rate of the dendritic polymers prepared in Examples 1-4 is significantly higher than that of PESA and PASP, indicating that the dendritic polymers grafted with polyoxyethylene structures have better scale inhibition effects. With prolonged use, the rate of decrease in the scale inhibition rate of the dendritic polymers is significantly lower than that of PESA and PASP, suggesting that the dendritic polymers have a longer service life and good application prospects in water industry systems.

[0151] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A dendritic polymer containing a polyoxyethylene structure, characterized in that, The general structural formula of the dendritic polymer is as follows: ， Where: the general structural formula of R is: ， The number of repeating units m is an integer from 1 to 100, n is a natural number, the degree of aggregation x is 1-5000, and the degree of aggregation y is 1-5000.

2. A method for preparing a dendritic polymer containing a polyoxyethylene structure as described in claim 1, characterized in that, Includes the following steps: Polyamine compounds were subjected to an epoxy addition reaction to obtain dendritic nitrogen-containing polyether monomers with a polyoxyethylene structure. After modifying the dendritic nitrogen-containing polyether monomer with unsaturated groups, a modified dendritic nitrogen-containing polyether monomer is obtained. The modified dendritic nitrogen-containing polyether monomer undergoes a free radical copolymerization reaction with unsaturated organic acids and unsaturated sulfonates in the presence of an initiator.

3. The preparation method according to claim 2, characterized in that, In the preparation of the dendritic nitrogen-containing polyether monomer, ethylene oxide is used to perform an epoxide addition reaction on the polyamine compound in an oxygen-free environment.

4. The preparation method according to claim 2, characterized in that, In the preparation of the modified dendritic nitrogen-containing polyether monomer, unsaturated carboxylic acids are used to modify the dendritic nitrogen-containing polyether monomer with unsaturated groups.

5. The preparation method according to claim 2, characterized in that, During the free radical copolymerization process, the reaction temperature is 75–95℃ and the reaction time is 1–5 hours.

6. The preparation method according to claim 2 or 3, characterized in that, The reaction temperature in the preparation of the dendritic nitrogen-containing polyether monomer is 120~140℃, and the reaction pressure is 0.2~0.4Mpa.

7. The preparation method according to claim 2 or 4, characterized in that, The reaction temperature in preparing the modified dendritic nitrogen-containing polyether monomer is 60–80°C, and the reaction time is 1–5 hours.

8. A phosphorus-free corrosion and scale inhibitor, characterized in that, The components include the following parts by weight: 0.1 to 15 parts of the dendritic polymer containing a polyoxyethylene structure as described in claim 1 0.1 to 10 parts of polyepoxysuccinic acid or polyepoxysuccinate 0.1 to 5 parts gluconate Inorganic zinc salt 0.1–5 parts Citric acid 0.1–5 parts Solvent 60~99.5 parts.

9. The phosphorus-free corrosion and scale inhibitor according to claim 8, characterized in that, The components include the following parts by weight: 5-10 parts of the dendritic polymer containing a polyoxyethylene structure as described in claim 1 2-5 parts of polyepoxysuccinic acid or polyepoxysuccinate 1-3 parts gluconate 2-4 parts of inorganic zinc salt Citric acid 2-3 parts Solvent 75-88 parts.

10. The application of a phosphorus-free corrosion and scale inhibitor as described in claim 8 or 9 in an industrial water system.

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