Polymer scale inhibitor and preparation method thereof

Abstract

The present invention discloses a polymer scale inhibitor and a preparation method thereof, and belongs to the technical field of polymer and water treatment. The polymer scale inhibitor has the following general formula: wherein m, n and p are any integers of 1-10 respectively. In addition, the present invention also proposes a preparation method of the polymer scale inhibitor, comprising the following steps: mixing acrylic acid and water, then adding ACMO and 2-aminopyridine, then dropping an initiator at 45-50°C, and then reacting at 50-60°C to obtain the polymer scale inhibitor. The polymer scale inhibitor proposed by the present invention significantly improves the scale inhibition performance of the scale inhibitor.

Description

Technical Field

[0001] The invention relates to the technical field of polymers and water treatment, and in particular to a polymer scale inhibitor and a preparation method thereof. Background Art

[0002] In response to the increasingly serious scaling problem in oilfield production, many anti-scaling and descaling technologies have been developed at home and abroad. Although each has its own advantages in scale prevention and control, the squeeze injection anti-scaling agent technology is the most mature and widely used. As a representative of green anti-scaling agents, polyacrylic acid anti-scaling agents have been widely used in many fields because their molecules do not contain phosphorus, have good biodegradability, and do not pollute the environment.

[0003] Polyacrylic acid (PAA) molecules contain carboxyl groups. Carboxyl groups can be ionized in aqueous solution to produce carboxyl anions, which can react with Ca in oilfield water. 2+ , Cu 2+ , Fe 3+ It can chelate metal ions such as ions, thereby increasing the solubility of these metal ions in water and is widely used in the field of scale inhibition. However, as a water treatment agent, due to its single structure, its scale inhibition performance is not very outstanding. Therefore, researchers have made many efforts to modify it and reduce the cost of use by increasing the scale inhibition rate. How to improve the scale inhibition performance of scale inhibitors is a technical problem that needs to be solved in the prior art. Summary of the invention

[0004] The purpose of the present invention is to overcome the above technical deficiencies, provide a polymer scale inhibitor and a preparation method thereof, and solve the technical problem of how to improve the scale inhibition performance of the scale inhibitor in the prior art.

[0005] In order to achieve the above technical purpose, the technical solution of the present invention provides a polymer scale inhibitor having the following general formula:

[0006]

[0007] Wherein m, n and p are any integers from 1 to 10 respectively.

[0008] In addition, the present invention also provides a method for preparing a polymer scale inhibitor, comprising the following steps:

[0009] Acrylic acid and water are mixed, ACMO and 2-aminopyridine are added, an initiator is added dropwise at 45-50° C., and the polymer scale inhibitor is reacted at 50-60° C. to obtain the polymer scale inhibitor.

[0010] In any embodiment, the molar ratio of the acrylic acid to the 2-aminopyridine is (3-4):(1-2).

[0011] In any embodiment, the molar ratio of the acrylic acid to the ACMO is (3-4):(0.1-1).

[0012] In any embodiment, the amount of the initiator added is 8%-15% of the total mass of acrylic acid, 2-aminopyridine and ACMO.

[0013] In any embodiment, the initiator is ammonium persulfate.

[0014] In any embodiment, the time required for dropwise adding the initiator is 45 minutes to 60 minutes.

[0015] In any embodiment, the reaction time at 50-60° C. is 30 minutes to 60 minutes.

[0016] In any embodiment, mixing acrylic acid and water comprises: mixing acrylic acid and water and reacting at 25-35° C. for 30 minutes to 40 minutes.

[0017] Compared with the prior art, the beneficial effects of the present invention include: the polymer scale inhibitor proposed by the present invention introduces acylamino groups into polyacrylic acid. The amide group is a functional group in the polyelectrolyte scale inhibitor dispersant, which has excellent inhibitory effect and dispersing performance on the deposition of iron oxide, calcium phosphate, zinc phosphate and calcium carbonate in water. After the amide group is introduced, the polymer contains both carboxyl groups and amide groups, and the scale inhibition effect is significantly improved. At the same time, the introduction of amide groups also solves the problem of gelation caused by excessive carboxyl content in polyacrylic acid; in addition, the morpholine group is hydrophilic, and its introduction enhances the hydrophilicity of the polymer, thereby significantly improving the scale inhibition performance of the scale inhibitor. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is the infrared spectrum of the scale inhibitor prepared in Example 1 of the present invention. DETAILED DESCRIPTION

[0019] The "range" disclosed in the present application is defined in the form of a lower limit and an upper limit, and a given range is defined by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundaries of the particular range. The range defined in this way can be inclusive or exclusive of the end values, and can be arbitrarily combined, that is, any lower limit can be combined with any upper limit to form a range. For example, if a range of 60 to 120 and 80 to 110 is listed for a particular parameter, it is understood that a range of 60 to 110 and 80 to 120 is also expected. In addition, if the minimum range values ​​1 and 2 are listed, and if the maximum range values ​​3, 4 and 5 are listed, the following ranges can all be expected: 1 to 3, 1 to 4, 1 to 5, 2 to 3, 2 to 4 and 2 to 5. In the present application, unless otherwise specified, the numerical range "a to b" represents an abbreviation of any real number combination between a and b, where a and b are both real numbers. For example, the numerical range "0-5" means that all real numbers between "0-5" are listed in this document, and "0-5" is just an abbreviation of these numerical combinations. In addition, when a parameter is expressed as an integer ≥ 2, it is equivalent to disclosing that the parameter is, for example, an integer of 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0020] If there is no special explanation, the "include" and "comprising" mentioned in this application are open-ended or closed-ended. For example, the "include" and "comprising" may mean that other components not listed may also be included or only the listed components may be included or only the listed components may be included.

[0021] If not specifically stated, in this application, the term "or" is inclusive. For example, the phrase "A or B" means "A, B, or both A and B". More specifically, any of the following conditions satisfies the condition "A or B": A is true (or exists) and B is false (or does not exist); A is false (or does not exist) and B is true (or exists); or both A and B are true (or exist).

[0022] This specific embodiment provides a polymer scale inhibitor having the following general formula:

[0023]

[0024] Wherein m, n and p are any integers from 1 to 10 respectively.

[0025] In addition, this specific embodiment also proposes a method for preparing a polymer scale inhibitor, comprising the following steps:

[0026] Acrylic acid and water are mixed and reacted at 25-35°C for 30-40 minutes, then ACMO (i.e., 4-acryloylmorpholine) and 2-aminopyridine are added, then an initiator is added dropwise at 45-50°C for 45-60 minutes, and then the polymer scale inhibitor is obtained by reacting at 50-60°C for 30-60 minutes; the molar ratio of the acrylic acid to the 2-aminopyridine is (3-4):(1-2); the molar ratio of the acrylic acid to the ACMO is (3-4):(0.1-1); the amount of the initiator added is 8%-15% of the total mass of the acrylic acid, 2-aminopyridine and ACMO; and the initiator is ammonium persulfate.

[0027] The reaction equation is as follows:

[0028]

[0029] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0030] In the present invention, reference is made to “some embodiments”, “this embodiment”, examples, etc., which describe a subset of all possible embodiments, but it can be understood that “some embodiments” may be the same subset or different subsets of all possible embodiments and may be combined with each other without conflict.

[0031] If similar descriptions of "first / second" appear in the application documents, the following instructions are added. In the following description, the terms "first\second\third" involved are merely used to distinguish similar objects and do not represent a specific ordering of the objects. It can be understood that "first\second\third" can be interchanged in a specific order or sequence where permitted, so that the embodiments described herein can be implemented in an order other than that illustrated or described herein.

[0032] In this embodiment, the term "and / or" is merely a description of the association relationship between associated objects, indicating that three relationships may exist. For example, object A and / or object B may represent three situations: object A exists alone, object A and object B exist at the same time, and object B exists alone.

[0033] Hereinafter, the embodiments of the present application will be described. The embodiments described below are exemplary and are only used to explain the present application, and should not be construed as limiting the present application. If no specific techniques or conditions are indicated in the embodiments, the techniques or conditions described in the literature in this area or the product specifications are used. If the manufacturer is not indicated in the reagents or instruments used, they are all conventional products that can be obtained commercially.

[0034] Example 1

[0035] This embodiment provides a polymer antiscalant, which is prepared by the following steps:

[0036] Acrylic acid and deionized water were mixed in a mass ratio of 1:2 and added to a three-necked flask, and reacted at 25-35°C for half an hour. Then ACMO and 2-aminopyridine were added, wherein the molar ratio of acrylic acid, ACMO and 2-aminopyridine was 1:0.5:0.25. Then the temperature was raised to 50°C, and the initiator APS was added dropwise to the three-necked flask, the amount of the initiator added was 15% of the total mass of acrylic acid, ACMO and 2-aminopyridine, and the initiator was added dropwise for 45 minutes. After the addition was completed, the reaction was continued at 55°C for half an hour to obtain the polymer scale inhibitor.

[0037] Figure 1 This is the infrared spectrum of the polymer scale inhibitor prepared in this example. It can be clearly seen from the spectrum that at 1737 cm -1 There is stretching vibration, which is the stretching vibration of C=O in -COOH. 3427.9cm -1 The stretching vibration at 3104.5cm is the stretching vibration of -OH in -COOH, proving that the product contains -COOH. -1 The peak at 1413.5cm is the stretching vibration of C=O in the amide I band, and the peak at 1640.5 is the stretching vibration of -NH in the amide III band. -1 The stretching vibration of -CN in the amide group indicates that 2-aminopyridine is grafted onto acrylic acid. -1 The absorption peak at is the stretching vibration of -CN in morpholine. This means that acrylic acid is connected to acryloylmorpholine. All these show that the introduction of ACMO and 2-aminopyridine into polyacrylic acid significantly improves the comprehensive performance of polyacrylic acid and its scale inhibition ability.

[0038] Example 2

[0039] This embodiment provides a polymer antiscalant, which is prepared by the following steps:

[0040] Acrylic acid and deionized water are mixed in a mass ratio of 1:2 and added into a three-necked flask. After reacting at 25-35°C for half an hour, ACMO and 2-aminopyridine are added, wherein the molar ratio of acrylic acid, ACMO and 2-aminopyridine is 1:0.5:0.25. The temperature is then raised to 50°C, and initiator APS is added dropwise into the three-necked flask. The amount of the initiator added is 8% of the total mass of acrylic acid, ACMO and 2-aminopyridine. The initiator is added dropwise for 45 minutes. After the addition is completed, the reaction is continued at 55°C for 45 minutes to obtain the polymer scale inhibitor.

[0041] Example 3

[0042] This embodiment provides a polymer antiscalant, which is prepared by the following steps:

[0043] Acrylic acid and deionized water are mixed in a mass ratio of 1:2 and added into a three-necked flask. After reacting at 25-35°C for half an hour, ACMO and 2-aminopyridine are added, wherein the molar ratio of acrylic acid, ACMO and 2-aminopyridine is 1:0.5:0.25. The temperature is then raised to 50°C, and initiator APS is added dropwise into the three-necked flask. The amount of the initiator added is 10% of the total mass of acrylic acid, ACMO and 2-aminopyridine. The initiator is added dropwise for 60 minutes. After the addition is completed, the reaction is continued at 50°C for 30 minutes to obtain the polymer scale inhibitor.

[0044] Example 4

[0045] This embodiment provides a polymer antiscalant, which is prepared by the following steps:

[0046] Acrylic acid and deionized water are mixed in a mass ratio of 1:2 and added into a three-necked flask. After reacting at 25-35°C for half an hour, ACMO and 2-aminopyridine are added, wherein the molar ratio of acrylic acid, ACMO and 2-aminopyridine is 3:1:1. The temperature is then raised to 50°C, and initiator APS is dripped into the three-necked flask. The amount of the initiator added is 10% of the total mass of acrylic acid, ACMO and 2-aminopyridine. The initiator is dripped for 60 minutes. After the dripping is completed, the reaction is continued at 60°C for 60 minutes to obtain the polymer scale inhibitor.

[0047] Comparative Example 1

[0048] This comparative example proposes a polymer antiscalant, which is prepared by the following steps:

[0049] The difference between this comparative example and Example 1 is that 2-aminopyridine is not added, the amount of ACMO added is the sum of the amounts of ACMO and 2-aminopyridine in Example 1, and other raw materials and amounts, and reaction conditions are the same as those in Example 1.

[0050] Comparative Example 2

[0051] This comparative example proposes a polymer antiscalant, which is prepared by the following steps:

[0052] The difference between this comparative example and Example 1 is that ACMO is not added, the amount of 2-aminopyridine added is the sum of the amounts of ACMO and 2-aminopyridine in Example 1, and other raw materials and amounts, and reaction conditions are the same as those in Example 1.

[0053] Comparative Example 3

[0054] This comparative example proposes a polymer antiscalant, which is prepared by the following steps:

[0055] The difference between this comparative example and Example 1 is that 2-aminopyridine is replaced by 4-aminopyridine, and the other steps and reaction conditions are the same as those in Example 1;

[0056] Specifically, acrylic acid and deionized water are mixed in a mass ratio of 1:2 and added to a three-necked flask, and reacted at 25-35°C for half an hour. Then ACMO and 4-aminopyridine are added, wherein the molar ratio of acrylic acid, ACMO and 4-aminopyridine is 1:0.5:0.25. Then the temperature is raised to 50°C, and the initiator APS is added dropwise to the three-necked flask, the amount of the initiator added is 15% of the total mass of acrylic acid, ACMO and 4-aminopyridine, and the initiator is added dropwise for 45 minutes. After the addition is completed, the reaction is continued at 55°C for half an hour to obtain the polymer scale inhibitor.

[0057] Scale inhibition performance test

[0058] The scale inhibition performance of the polymer scale inhibitor products prepared in Examples 1-3 and Comparative Examples 1-3 on calcium carbonate and calcium sulfate was tested in the following manner:

[0059] Accurately weigh 0.50 g of scale inhibitor, dissolve it in a small amount of pure water, transfer it to a 250 mL volumetric flask and dilute it to the scale to obtain a scale inhibitor solution.

[0060] Calcium carbonate: Take 200mL of pure water in a 250mL volumetric flask and add the pre-prepared CaCl2 solution to prepare Ca 2+ Content: 96.00 mg·mL -1 Add 3.75mL of antiscalant solution, let stand for 10 minutes, then add the pre-prepared Na2CO3 solution while shaking to make CO3 2- Content: 150.72 mg·mL -1 . Add pure water to dilute to the scale and put it into a ground-mouth conical flask, put it in a water bath at 50℃±1℃ for half an hour and then let it stand for 16 hours.

[0061] Calcium sulfate: Take 150mL of pure water in a 250mL volumetric flask and add the pre-prepared CaCl2 solution to make Ca 2+ Content: 3000mg·mL -1 . Add 3.75mL of antiscalant solution, let it stand for 10 minutes, then add the pre-prepared Na2SO4 solution while shaking to make SO4 2- Content: 7335mg·mL -1Dilute with pure water to the mark and put into a ground-mouth conical flask, place in a water bath at 50℃±1℃ for half an hour and then let stand for 24 hours.

[0062] When the reaction is complete, the solution is cooled to room temperature and filtered with quantitative filter paper. The filtrates of CaCO3 and CaSO4 are titrated with ethylenediaminetetraacetic acid (EDTA) standard solution to determine Ca 2+ The blank test was carried out at the same time. The scale inhibition performance is shown in Table 1 and Table 2.

[0063] Table 1 Calcium carbonate static test

[0064] Group Antiscalant dosage (mg / L) Anti-scaling efficiency (%) Example 1 30 91.6 Example 2 30 93.5 Example 3 30 96.3 Example 4 30 95.1 Comparative Example 1 30 45.4 Comparative Example 2 30 57.2 Comparative Example 3 30 63.6

[0065] It can be seen from Table 1 that the scale inhibitor proposed in the present invention has an excellent scale inhibition effect on calcium carbonate, especially in Example 3, the scale inhibition efficiency can be as high as 96.3%.

[0066] Table 2 Calcium sulfate static test

[0067] Group Antiscalant dosage (mg / L) Anti-scaling efficiency (%) Example 1 30 83 Example 2 30 83.7 Example 3 30 90.5 Example 4 30 85.8 Comparative Example 1 30 51.1 Comparative Example 2 30 48.2 Comparative Example 3 30 62.1

[0068] It can be seen from Table 2 that the scale inhibitor proposed in the present invention also has a good scale inhibition effect on calcium sulfate, which can reach more than 80%, and the best effect can reach 90.5%. From the scale inhibition effects of the above examples 1 to 4 on calcium carbonate and calcium sulfate, the scale inhibitor proposed in the present invention is a high-efficiency scale inhibitor worthy of promotion.

[0069] The specific implementation of the present invention described above does not constitute a limitation on the protection scope of the present invention. Any other corresponding changes and modifications made based on the technical concept of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A polymer scale inhibitor, characterized in that: It has the following general formula: Wherein m, n and p are any integers from 1 to 10 respectively.

2. A method for preparing a polymer scale inhibitor, characterized in that: The following steps are involved: Acrylic acid and water are mixed, ACMO and 2-aminopyridine are added, an initiator is added dropwise at 45-50° C., and the polymer scale inhibitor is reacted at 50-60° C. to obtain the polymer scale inhibitor.

3. The method for preparing a polymer scale inhibitor according to claim 2, characterized in that: The molar ratio of the acrylic acid to the 2-aminopyridine is (3-4):(1-2).

4. The method for preparing a polymer scale inhibitor according to claim 2, characterized in that: The molar ratio of the acrylic acid to the ACMO is (3-4):(0.1-1).

5. The method for preparing a polymer scale inhibitor according to claim 2, characterized in that: The added amount of the initiator is 8%-15% of the total mass of acrylic acid, 2-aminopyridine and ACMO.

6. The method for preparing a polymer scale inhibitor according to claim 2 or 5, characterized in that: The initiator is ammonium persulfate.

7. The method for preparing a polymer scale inhibitor according to claim 2 or 5, characterized in that: The time required for dropwise addition of the initiator is 45 to 60 minutes.

8. The method for preparing a polymer scale inhibitor according to claim 2, characterized in that: The reaction time at 50-60°C is 30 minutes to 60 minutes.

9. The method for preparing a polymer scale inhibitor according to claim 2, characterized in that: The mixing of acrylic acid and water comprises: mixing acrylic acid and water and reacting them at 25-35° C. for 30 minutes to 40 minutes.

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