CN111253516A

CN111253516A - Novel environment-friendly polyether scale inhibitor, and preparation method and application thereof

Info

Publication number: CN111253516A
Application number: CN202010177733.8A
Authority: CN
Inventors: 张巧玲; 乔昌兵; 陈春坛; 章小龙; 张艳; 张裕鲛; 蒲虹畅; 冯刚
Original assignee: Sichuan Aite Intelligent Laboratory Technology Co Ltd; SICHUAN UNIVERSITY OF ARTS AND SCIENCE; Sichuan Yuge Qintian Environmental Protection Technology Co Ltd
Current assignee: Sichuan Aite Intelligent Laboratory Technology Co Ltd; SICHUAN UNIVERSITY OF ARTS AND SCIENCE; Sichuan Yuge Qintian Environmental Protection Technology Co Ltd
Priority date: 2020-03-13
Filing date: 2020-03-13
Publication date: 2020-06-09

Abstract

The invention discloses a novel environment-friendly polyether scale inhibitor, a preparation method and application thereof, belonging to the field of high polymer materials. The polyether scale inhibitor is subjected to copolymerization reaction in an aqueous solution, the polymerization temperature is about 80 ℃, and the process conditions are mild; meanwhile, the raw materials do not contain N, P, S and other elements, the target product belongs to a green environment-friendly product, and the biodegradation rate is high; in the whole preparation process, no waste gas, waste liquid or waste residue is generated, the process is reasonable, the requirement of industrial production can be met, and the method is economically favorable; the target product is a viscous liquid, so that the transportation and the storage are convenient; the method meets the requirement of green chemical development, and has good environmental protection benefit and social benefit.

Description

Novel environment-friendly polyether scale inhibitor, and preparation method and application thereof

Technical Field

The invention relates to the field of high polymer materials, in particular to the field of polyether scale inhibitors, and specifically relates to a novel environment-friendly polyether scale inhibitor, and a preparation method and application thereof. The scale inhibitor is an environment-friendly and efficient scale inhibitor, is mild in preparation conditions, is green and environment-friendly, and has a certain application value.

Background

With the development of economy and society, the demand for water resources is increasing day by day, and the contradiction between supply and demand of water resources is prominent day by day. Therefore, how to reduce the industrial water and reasonably treat and recycle the industrial wastewater is highly valued by people. In the process of recycling cooling water, along with the continuous evaporation and concentration of water, the concentration of inorganic salt ions in water is gradually increased and deposited on the surface of heat exchange equipment to form dirt, so that the efficiency of the heat exchanger is reduced, and the corrosion is aggravated. Therefore, scale inhibition is a problem to be solved.

Aiming at the problem of cooling water scale, the most common scale inhibition method at present is to add a scale inhibitor into circulating water. The scale inhibitor has been developed to date, has various types and quantities, and passes through several stages such as inorganic polyphosphate, organic polyphosphonic acid (salt), polycarboxylic acid, binary and ternary phosphorus-containing copolymer, binary and ternary low-phosphorus and phosphorus-free copolymer and the like. In recent years, with the increase of the awareness of environmental protection of human beings, the development of green environmental water treatment agents has become a hot topic for the research of scholars at home and abroad.

Therefore, the invention provides a polyether scale inhibitor which is used in the field of water treatment.

Disclosure of Invention

The invention aims to: aiming at the problems, the novel environment-friendly polyether scale inhibitor, the preparation method and the application thereof are provided. The scale inhibitor takes Maleic Anhydride (MA), fatty alcohol-polyoxyethylene ether (AEO-7) and sodium hydroxide as raw materials, potassium persulfate as an initiator, and performs copolymerization reaction in a water solution to synthesize a novel polyether scale inhibitor integrating a carboxylic group, an ester group and an ether group. The scale inhibitor has mild reaction conditions, does not contain N, P, S and other elements in the raw materials, belongs to a green environment-friendly product, and has high biodegradation rate. Meanwhile, the scale inhibitor does not generate waste gas, waste liquid or waste residue in the preparation process, meets the requirement of green chemical development, has better environmental protection benefit and social benefit, and is worthy of large-scale popularization and application.

In order to achieve the purpose, the invention adopts the following technical scheme:

a novel environment-friendly polyether scale inhibitor has a structural formula as follows:

in the formula: m and n respectively represent the number of repeating units, m is a natural number of 1-3, n is a natural number of 1-3, and the viscosity average molecular weight is 775-1283.

The application also provides a preparation method of the novel environment-friendly polyether scale inhibitor, which comprises the following steps: the polyether scale inhibitor is prepared by two steps of esterification and polymerization in an aqueous solution by taking maleic anhydride, fatty alcohol-polyoxyethylene ether and first caustic alkali as raw materials and potassium persulfate as an initiator; the first caustic alkali is one or two of sodium hydroxide and potassium hydroxide.

The fatty alcohol-polyoxyethylene ether is AEO-7.

The method comprises the following steps:

(1) mixing fatty alcohol-polyoxyethylene ether AEO-7 and maleic anhydride according to a molar ratio of 1: 1.05-1.2 to obtain a first mixture; reacting the first mixture at the constant temperature of 65-70 ℃ for 3.0-5.0 h, and quickly adding a first caustic alkali aqueous solution into the mixture for neutralization after the constant temperature reaction is finished to obtain a polyether macromonomer;

(2) mixing maleic anhydride and first caustic alkali according to the molar ratio of 1: 1.5-3.0 to obtain a third mixture, and heating the third mixture to 78-82 ℃; dropwise adding the reaction solution into the heated third mixture within 1-1.5 h to obtain a fourth mixture; continuously reacting the fourth mixture at 78-82 ℃ for 3-4 h, and then heating to 83-87 ℃ for 2-3 h to obtain the novel environment-friendly polyether scale inhibitor;

in the step (2), the reaction solution is an aqueous solution of a polyether macromonomer and potassium persulfate; the molar ratio of the maleic anhydride in the step (2) to the polyether macromonomer in the reaction solution is 4-8: 1, and the mass of the potassium persulfate in the reaction solution is 8-12% of the mass of the maleic anhydride in the step (2);

the first caustic alkali is one or two of sodium hydroxide and potassium hydroxide.

In the step 1, the first mixture is subjected to constant temperature reaction at 65-70 ℃ for 3.0-5.0 h, after the constant temperature reaction is completed, a first caustic alkali aqueous solution is rapidly added into the first mixture for neutralization to obtain a second mixture, and the solid content of the second mixture is kept to be about 25%, so that the polyether macromonomer is obtained.

In the step 2, maleic anhydride and first caustic alkali are mixed according to a molar ratio of 1:2.0 to obtain a third mixture; the third mixture has a solids content of 25%.

The novel environment-friendly polyether scale inhibitor is applied.

The novel environment-friendly polyether scale inhibitor is used for scale inhibition of circulating water.

The application provides a novel environmental protection polyetherThe scale inhibitor (PMAEO for short), the preparation method and the application thereof are prepared by two steps of esterification and polymerization in aqueous solution by using Maleic Anhydride (MA), fatty alcohol-polyoxyethylene ether (AEO-7) and first caustic alkali as raw materials and potassium persulfate as an initiator. In the application, the polyether scale inhibitor is combined with hydrogen atoms in water through ether bonds (-C-O-C-) in molecules to form hydrogen bonds, so that the water solubility of the scale inhibitor molecules is enhanced, and the inhibition effect of the scale inhibitor molecules on dirt is greatly improved. The polyether scale inhibitor takes maleic anhydride and fatty alcohol-polyoxyethylene ether (AEO-7) as raw materials, a novel polyether scale inhibitor integrating carboxylic acid groups, ester groups and ether groups is synthesized in a water solution, ions in the solution can be dispersed, and the effects of emulsification and solubilization are achieved, wherein the ether bonds can enhance the water solubility of the scale inhibitor, the tolerance to calcium ions is high, and the scale inhibitor has a good scale inhibition effect. The practical test result shows that: in Ca of the present application²⁺At a concentration of 250mg/L and an addition amount of 2mg/L, for CaCO₃The inhibitory capacity of (a) can reach 98%.

Further, the application provides a preparation method of the polyether scale inhibitor. Here, an example is described (in this example, sodium hydroxide is used as the first caustic alkali).

Firstly, adding fatty alcohol-polyoxyethylene ether (AEO-7) and Maleic Anhydride (MA) in a molar ratio of 1: 1.05-1: 1.2 into a round-bottom flask to obtain a first mixture; and (3) reacting the first mixture at a constant temperature of 65-70 ℃ for 3.0-5.0 h, quickly adding a sodium hydroxide aqueous solution into the first mixture until the mixture is neutral to obtain a second mixture, and keeping the solid content of the second mixture at 25% to obtain the polyether macromonomer.

Then, adding Maleic Anhydride (MA) and an aqueous solution of sodium hydroxide into a three-neck flask provided with a stirrer and a thermometer, controlling the molar ratio of the MA to the NaOH to be 1:2 and the solid content to be 25 percent, and obtaining a third mixture; keeping the temperature of the third mixture at 78-82 ℃, dropwise adding the reaction solution into the third mixture, and completing dropwise adding within 1-1.5 h to obtain a fourth mixture; and (3) reacting the fourth mixture at 78-82 ℃ for 3-4 h, and then continuously heating to 83-87 ℃ for reacting for 2-3 h to obtain the target product. Wherein the reaction solution is formed by mixing a polyether macromonomer, potassium persulfate and water; wherein, based on the maleic anhydride in the step (2), the molar ratio of the maleic anhydride in the step (2) to the polyether macromonomer in the added reaction solution is 4: 1-8: 1, and the mass of the potassium persulfate in the added reaction solution is 8-12% of the mass of the maleic anhydride in the step (2).

The correlation reaction equation is shown in the following formulas (1) to (4):

C₁₂H₂₅-(CH₂CH₂O)₇-OOC-CH＝CH-COOH+NaOH→C₁₂H₂₅-(CH₂CH₂O)₇-OOC-CH＝CH-COONa (2)；

the polyether scale inhibitor is subjected to copolymerization reaction in an aqueous solution, the polymerization temperature is about 80 ℃, and the process conditions are mild; meanwhile, the raw materials do not contain N, P, S and other elements, the target product belongs to a green environment-friendly product, and the biodegradation rate is high; in the whole preparation process, no waste gas, waste liquid or waste residue is generated, the process is reasonable, the requirement of industrial production can be met, and the method is economically favorable; the target product is a viscous liquid, so that the transportation and the storage are convenient; the method meets the requirement of green chemical development, and has good environmental protection benefit and social benefit.

Detailed Description

All of the features disclosed in this specification, or all of the steps in any method or process so disclosed, may be combined in any combination, except combinations of features and/or steps that are mutually exclusive.

Any feature disclosed in this specification may be replaced by alternative features serving equivalent or similar purposes, unless expressly stated otherwise. That is, unless expressly stated otherwise, each feature is only an example of a generic series of equivalent or similar features.

In the following, a solution in an embodiment of the present invention will be fully and specifically described, the described embodiment is only a part of the embodiment of the present invention, and other embodiments obtained by a person of ordinary skill in the art without any creative effort based on the embodiment of the present invention belong to the protection scope of the present invention.

The scale inhibitors prepared in the following examples were tested according to the national standard evaluation method (GB/T16632-2008), as follows: controlling the concentration of calcium ions in the solution to be 250mg/L, the concentration of bicarbonate ions to be 732mg/L and the pH value to be 7, adding scale inhibitors with different concentrations into the solution to prepare an experimental water sample, then placing the experimental water sample into a water bath with constant temperature of 80 ℃, taking out the experimental water sample after reacting for 10 hours, naturally cooling the experimental water sample, and titrating Ca in filtrate by using EDTA (ethylene diamine tetraacetic acid)²⁺The concentration of (c).

The calculation formula of the scale inhibition efficiency η is as follows:

in the formula (5), V₀The amount of EDTA (mL) required before the reaction without the addition of scale inhibitor; v₁The amount of EDTA (mL) required after the reaction without addition of scale inhibitor; v₂The amount of EDTA required after the reaction (mL) when the scale inhibitor was added.

Example 1

19.6g of fatty alcohol-polyoxyethylene ether (AEO-7) and 4.32g of Maleic Anhydride (MA) were added to a round-bottom flask to obtain a first mixture. The first mixture was reacted at a constant temperature of 65 ℃ for 3.5 hours, and 68ml of an aqueous solution of sodium hydroxide having a mass fraction of 2.4% was added thereto to obtain a polyether macromonomer.

28.7g of a polyether macromonomer was mixed with 1.57g of a 25% by mass aqueous solution of a potassium persulfate initiator to obtain a first reaction solution. To a three-necked flask equipped with a stirrer and a thermometer were added 4.9g of Maleic Anhydride (MA) and 27ml of an aqueous solution of sodium hydroxide having a mass fraction of 13% to obtain a third mixture. And heating the third mixture to 80 ℃, dropwise adding the prepared first reaction solution into the third mixture, and finishing dropwise adding within 1h to obtain a fourth mixture. And (3) reacting the fourth mixture at 80 ℃ for 3h, then heating to 85 ℃ and continuing to react for 2h to obtain the target product.

The samples prepared in this example were tested and the results are shown in Table 1.

Table 1 test results of example 1

Dosage (mg/L)	1	2	3	5	8	10	12
								[Ca²⁺]250mg/L CaCO₃(％)	94.5	98.3	97.6	96.5	96.4	96.6	96.3

As can be seen from the table above, when the adding amount of the scale inhibitor is 2mg/L, the scale inhibition rate on calcium carbonate scale is as high as 98%; and with the increase of the adding amount, the inhibition rate of the scale inhibitor prepared by the invention on calcium carbonate basically tends to be stable.

Example 2

To a round bottom flask were added 24.7g of fatty alcohol-polyoxyethylene ether (AEO-7) and 5.64g of Maleic Anhydride (MA) to obtain a first mixture. And reacting the first mixture at the constant temperature of 65 ℃ for 3 hours, and adding 90ml of a 2.2 mass percent sodium hydroxide aqueous solution to the mixture to obtain the polyether macromonomer.

57.4g of a polyether macromonomer was mixed with 3.92g of a 25% by mass aqueous solution of a potassium persulfate initiator to obtain a first reaction solution. To a three-necked flask equipped with a stirrer and a thermometer were added 9.8g of Maleic Anhydride (MA) and 61ml of an aqueous solution of sodium hydroxide having a mass fraction of 13% to obtain a third mixture. And regulating the reaction temperature of the third mixture to 80 ℃, dropwise adding the prepared first reaction solution into the third mixture, and completing dropwise adding within 1.5h to obtain a fourth mixture. And (3) reacting the fourth mixture at 80 ℃ for 4h, then heating to 85 ℃ and continuing to react for 2h to obtain the target product.

Table 2 test results of example 2

Dosage (mg/L)	1	2	3	5	8	10	12
								[Ca²⁺]250mg/L CaCO₃(％)	95.4	97.3	97.6	96.2	96.6	96.2	96.2

Example 3

To a round bottom flask were added 29.6g of fatty alcohol-polyoxyethylene ether (AEO-7) and 7.06g of Maleic Anhydride (MA) to obtain a first mixture. The first mixture was reacted at a constant temperature of 65 ℃ for 3 hours, and 117ml of an aqueous solution of sodium hydroxide having a mass fraction of 2.8% was added thereto to obtain a polyether macromonomer.

45.8g of a polyether macromonomer was mixed with 3.14g of a 25% by mass aqueous solution of a potassium persulfate initiator to obtain a first reaction solution. To a three-necked flask equipped with a stirrer and a thermometer were added 9.8g of Maleic Anhydride (MA) and 61ml of an aqueous solution of sodium hydroxide having a mass fraction of 13% to obtain a third mixture. And regulating the reaction temperature of the third mixture to 80 ℃, dropwise adding the first reaction solution into the third mixture, and finishing dropwise adding within 1h to obtain a fourth mixture. And reacting the fourth mixture at 80 ℃ for 3.5h, then heating to 85 ℃ and continuing to react for 2.5h to obtain the target product.

The samples prepared in this example were tested and the results are shown in Table 3.

Table 3 test results of example 3

Dosage (mg/L)	1	2	3	5	8	10	12
								[Ca²⁺]250mg/L CaCO₃(％)	93.4	97.5	98.2	97.5	97.2	96.5	96.5

Example 4

19.8g of fatty alcohol-polyoxyethylene ether (AEO-7) and 4.7g of Maleic Anhydride (MA) were added to a round-bottom flask to obtain a first mixture. The first mixture was reacted at a constant temperature of 65 ℃ for 3.5 hours, and 78ml of an aqueous solution of sodium hydroxide having a mass fraction of 2.8% was added thereto to obtain a polyether macromonomer.

30.6g of a polyether macromonomer was mixed with 3.14g of a 25% by mass aqueous solution of a potassium persulfate initiator to obtain a first reaction solution. To a three-necked flask equipped with a stirrer and a thermometer were added 7.84g of Maleic Anhydride (MA) and 49ml of an aqueous solution of sodium hydroxide having a mass fraction of 13% to obtain a third mixture. And heating the third mixture to 80 ℃, dropwise adding the prepared first reaction solution into the third mixture, and completing dropwise adding within 1.5h to obtain a fourth mixture. And (3) reacting the fourth mixture at 80 ℃ for 4h, then heating to 85 ℃ and continuing to react for 3h to obtain the target product.

The samples prepared in this example were tested and the results are shown in Table 4.

Table 4 test results of example 4

Dosage (mg/L)	1	2	3	5	8	10	12
								[Ca²⁺]250mg/L CaCO₃(％)	92.5	96.8	97.5	97.8	96.5	95.5	96.1

Example 5

To a round bottom flask were added 34.6g of fatty alcohol-polyoxyethylene ether (AEO-7) and 7.2g of Maleic Anhydride (MA) to obtain a first mixture. The first mixture was reacted at a constant temperature of 70 ℃ for 4 hours, and 130ml of an aqueous solution of sodium hydroxide having a mass fraction of 2.4% was added thereto to obtain a polyether macromonomer.

38.3g of a polyether macromonomer was mixed with 4.7g of a 25% by mass aqueous solution of a potassium persulfate initiator to obtain a first reaction solution. To a three-necked flask equipped with a stirrer and a thermometer were added 9.8g of Maleic Anhydride (MA) and 61ml of an aqueous solution of sodium hydroxide having a mass fraction of 13% to obtain a third mixture. And heating the third mixture to 80 ℃, dropwise adding the prepared first reaction solution into the third mixture, and finishing dropwise adding within 1h to obtain a fourth mixture. And (3) reacting the fourth mixture at 80 ℃ for 4h, then heating to 85 ℃ and continuing to react for 3h to obtain the target product.

The samples prepared in this example were tested and the results are shown in Table 5.

Table 5 test results of example 5

Dosage (mg/L)	1	2	3	5	8	10	12
								[Ca²⁺]250mg/L CaCO₃(％)	93.8	96.5	97.2	97.5	95.8	96.3	95.8

Example 6

To a round bottom flask were added 22.23g of fatty alcohol-polyoxyethylene ether (AEO-7) and 4.85g of Maleic Anhydride (MA) to obtain a first mixture. The first mixture was reacted at 70 ℃ for 4.5 hours, and 85ml of an aqueous solution of sodium hydroxide having a mass fraction of 2.5% was added thereto to obtain a polyether macromonomer.

26.23g of a polyether macromonomer was mixed with 3.76g of a 25% by mass aqueous solution of a potassium persulfate initiator to obtain a first reaction solution. To a three-necked flask equipped with a stirrer and a thermometer were added 7.84g of Maleic Anhydride (MA) and 49ml of an aqueous solution of sodium hydroxide having a mass fraction of 13% to obtain a third mixture. And heating the third mixture to 80 ℃, dropwise adding the prepared first reaction solution into the third mixture, and completing dropwise adding within 1.5h to obtain a fourth mixture. And reacting the fourth mixture at 80 ℃ for 3.5h, then heating to 85 ℃ and continuing to react for 2.5h to obtain the target product.

The samples prepared in this example were tested and the results are shown in Table 6.

Table 6 test results of example 6

Dosage (mg/L)	1	2	3	5	8	10	12
								[Ca²⁺]250mg/L CaCO₃(％)	93.3	95.7	96.6	97.8	96.8	96.8	97.2

Example 7

To a round bottom flask were added 24.7g of fatty alcohol-polyoxyethylene ether (AEO-7) and 5.64g of Maleic Anhydride (MA) to obtain a first mixture. The first mixture was reacted at a constant temperature of 70 ℃ for 5 hours, and 96ml of an aqueous solution of sodium hydroxide having a mass fraction of 2.6% was added thereto to obtain a polyether macromonomer.

34.44g of a polyether macromonomer was mixed with 5.64g of a 25% by mass aqueous solution of a potassium persulfate initiator to obtain a first reaction solution. To a three-necked flask equipped with a stirrer and a thermometer were added 11.76g of Maleic Anhydride (MA) and 74ml of an aqueous solution of sodium hydroxide having a mass fraction of 13% to obtain a third mixture. And heating the third mixture to 80 ℃, dropwise adding the prepared first reaction solution into the third mixture, and completing dropwise adding within 1.5h to obtain a fourth mixture. And reacting the fourth mixture at 80 ℃ for 3.5h, then heating to 85 ℃ and continuing to react for 2.5h to obtain the target product.

The samples prepared in this example were tested and the results are shown in Table 7.

Table 7 test results of example 7

Dosage (mg/L)	1	2	3	5	8	10	12
								[Ca²⁺]250mg/L CaCO₃(％)	93.6	96.8	98.2	97.7	96.8	97.2	96.8

The invention is not limited to the foregoing embodiments. The invention extends to any novel feature or any novel combination of features disclosed in this specification and any novel method or process steps or any novel combination of features disclosed.

Claims

1. A novel environment-friendly polyether scale inhibitor is characterized in that the structural formula is as follows:

in the formula: m is a natural number of 1-3, n is a natural number of 1-3, and the viscosity average molecular weight is 775-1283.

2. The preparation method of the novel environment-friendly polyether scale inhibitor according to claim 1, which is characterized by comprising the following steps: the polyether scale inhibitor is prepared by two steps of esterification and polymerization in an aqueous solution by taking maleic anhydride, fatty alcohol-polyoxyethylene ether and first caustic alkali as raw materials and potassium persulfate as an initiator; the first caustic alkali is one or two of sodium hydroxide and potassium hydroxide.

3. The preparation method of the novel environment-friendly polyether scale inhibitor according to claim 2, wherein the fatty alcohol-polyoxyethylene ether is AEO-7.

4. The preparation method of the novel environment-friendly polyether scale inhibitor according to claim 2 or 3, which is characterized by comprising the following steps:

5. The preparation method of the novel environment-friendly polyether scale inhibitor according to claim 4, wherein in the step 1, the first mixture is subjected to a constant temperature reaction at 65-70 ℃ for 3.0-5.0 h, and after the constant temperature reaction is completed, a first caustic alkali aqueous solution is rapidly added to neutralize the first mixture to neutrality, so that a second mixture, namely the polyether macromonomer, is obtained.

6. The method for preparing the novel environment-friendly polyether scale inhibitor according to any one of claims 4 to 5, wherein in the step 2, maleic anhydride and sodium hydroxide are mixed according to a molar ratio of 1:2.0 to obtain a third mixture.

7. The use of the novel environmentally friendly polyether scale inhibitor of claim 1.

8. The use of claim 7, wherein the novel environment-friendly polyether scale inhibitor is used for scale inhibition of circulating water.