A tetraphosphonic acid complex type corrosion and scale inhibitor, its preparation method and application

Abstract

The application discloses a tetraphosphonic acid composite corrosion and scale inhibitor and a preparation method and application thereof. In deionized water, (1,4-phenylene bis(hydroxymethanetriyl)) tetraphosphonic acid, styrene sodium sulfonate / aspartic acid / maleic acid terpolymer and zinc salt are sequentially added, and the tetraphosphonic acid composite corrosion and scale inhibitor is obtained after being uniformly mixed. The material is composed of the following components: (1,4-phenylene bis(hydroxymethanetriyl)) tetraphosphonic acid: 10-20%; styrene sodium sulfonate / aspartic acid / maleic acid terpolymer: 5-10%; zinc salt: 5-10%; and the rest is water. The application has good stability, can realize remarkable corrosion and scale inhibition effect under the condition of low dosage, has a simple preparation process and has a wide application prospect.

Description

Technical Field

[0001] This invention relates to the field of industrial circulating cooling water treatment technology, specifically to a tetraphosphonic acid composite corrosion and scale inhibitor, its preparation method, and its application. Background Technology

[0002] In industries such as petrochemicals, power generation, and metallurgy, the efficient operation of circulating water systems has dual value for intensive resource utilization and environmental protection. However, these systems have long faced the synergistic destructive effects of calcium and magnesium crystallization and electrochemical corrosion, resulting in operational losses such as a 15-30% decrease in heat transfer efficiency and a 3-5 year reduction in equipment lifespan. Developing water treatment agents with both corrosion inhibition and scale inhibition functions directly impacts the chemical stability and operational economy of industrial water systems.

[0003] In the field of industrial circulating water treatment, hydroxyethylidene diphosphonic acid (HEDP), as a traditional organophosphonic acid corrosion and scale inhibitor, is widely used due to its excellent calcium scale inhibition ability. However, its inherent defects are becoming increasingly apparent under high-parameter operating conditions. On the one hand, HEDP is prone to decomposition under high-temperature conditions, generating phosphate byproducts. These byproducts combine with calcium and magnesium ions in the water to form a hard scale layer, leading to a decrease in heat exchange efficiency and increased maintenance costs due to frequent cleaning. On the other hand, HEDP is extremely sensitive to iron ions in the water: when the iron ion concentration exceeds 3 mg / L, HEDP will preferentially combine with it and become ineffective. More seriously, the interaction between iron ions and HEDP can trigger localized acid corrosion, exacerbating the risk of pitting corrosion in equipment and shortening pipeline life. Therefore, developing a highly efficient corrosion and scale inhibition system with wide-range water quality adaptability has become a key technical bottleneck in solving the adaptability of industrial water treatment systems to complex operating conditions. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a tetraphosphonic acid composite corrosion and scale inhibitor, its preparation method and application, which has good stability, can achieve significant corrosion and scale inhibition effect under low dosage conditions, has a simple preparation process, and has broad application prospects.

[0005] To solve the above-mentioned technical problems, the present invention provides a method for preparing a tetraphosphonic acid composite corrosion and scale inhibitor, wherein (1,4-phenylenebis(hydroxymethanetriyl))tetraphosphonic acid, sodium styrene sulfonate / aspartic acid / maleic acid terpolymer and zinc salt are added sequentially to deionized water and mixed evenly to obtain a tetraphosphonic acid composite corrosion and scale inhibitor. The material is composed of the following components: (1,4-Phenylidenebis(hydroxymethanetriyl))tetraphosphonic acid: 10-20%; Sodium styrene sulfonate / aspartic acid / maleic acid terpolymer: 5-10%; Zinc salt: 5-10%; The rest is water.

[0006] Furthermore, the molecular formula of the (1,4-phenylenebis(hydroxymethanetriyl))tetraphosphonic acid is C8H. 14 O 14 P4 is prepared by reacting terephthaloyl chloride and tris(trimethylsilane) phosphite followed by hydrolysis; The specific method is as follows: Terephthaloyl chloride was added to tris(trimethylsilane) phosphite and stirred at room temperature for 0.5-1 h. After the reaction was completed, methanol solution was added to the mixture and reacted at room temperature for 0.5-1.5 h. After rotary evaporation, (1,4-phenylenebis(hydroxymethanetriyl))tetraphosphonic acid was obtained.

[0007] Furthermore, the sodium styrene sulfonate / aspartic acid / maleic acid terpolymer is copolymerized from sodium styrene sulfonate, aspartic acid, and maleic acid under the action of an initiator; The mass ratio of maleic acid, aspartic acid, sodium styrene sulfonate and initiator is 1:(0.55-1.15):(0.08-0.18):(0.035-0.12).

[0008] Furthermore, the initiator includes one or more of potassium persulfate, benzoyl peroxide, tert-butyl hydroperoxide, and isobutyl peroxide dicarbonate.

[0009] Furthermore, the zinc salt includes one or more of zinc sulfate and zinc chloride.

[0010] A tetraphosphonic acid composite corrosion and scale inhibitor is obtained by the above preparation method.

[0011] The application of a tetraphosphonic acid composite corrosion and scale inhibitor in a circulating cooling water system shows that when added to the circulating cooling water system, it can simultaneously achieve the effects of corrosion inhibition and scale inhibition.

[0012] The beneficial effects of the present invention are as follows: 1. The four phosphonic acid groups of the organophosphonic acid compound (1,4-phenylene bis(hydroxymethanetriyl)) tetraphosphonic acid disclosed in this application are rigidly bridged by 1,4-phenylene to form spatially symmetrical multidentate chelating sites, which have strong chelating binding with hard water ions such as calcium and magnesium in water. The coordination ability is significantly improved compared with HEDP, and it can effectively inhibit the formation of scale.

[0013] 2. The conjugation effect between the phosphonic acid group and the benzene ring can enhance the thermal stability of the molecule, making it more thermally stable than HEDP. This avoids high-temperature decomposition and the formation of phosphate scale, and can also alleviate the problem of eutrophication of water bodies to a certain extent.

[0014] 3. Since the composite scale inhibitor disclosed in this application contains (1,4-phenylenebis(hydroxymethanetriyl))tetraphosphonic acid, sodium styrene sulfonate / aspartic acid / maleic acid terpolymer and zinc salt, it has both corrosion inhibition and scale inhibition effects. When treating circulating cooling water, only a certain amount of this compound agent needs to be added to the liquid, which is more scientific and environmentally friendly. 4. The composite scale inhibitor disclosed in this application has a simple synthesis process and has good application prospects in the field of industrial circulating cooling water treatment. It also provides a new idea for developing green and efficient circulating cooling water treatment agents. Attached Figure Description

[0015] Figure 1 This is the infrared spectrum of (1,4-phenylenebis(hydroxymethanetriyl))tetraphosphonic acid of the present invention.

[0016] Figure 2 This is the infrared spectrum of the sodium styrene sulfonate / aspartic acid / maleic acid terpolymer of the present invention.

[0017] Figure 3 This is a molecular structure diagram of 1,4-phenylenebis(hydroxymethanetriyl)tetraphosphonic acid of the present invention.

[0018] Figure 4 This is a graph showing the experimental data of the present invention. Detailed Implementation

[0019] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments described are not intended to limit the present invention.

[0020] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0021] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0022] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0023] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0024] It should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0025] Reference Figures 1 to 4 As shown, an embodiment of the present invention discloses a tetraphosphonic acid composite corrosion and scale inhibitor, its preparation method, and its application. (1,4-phenylenebis(hydroxymethanetriyl))tetraphosphonic acid, sodium styrene sulfonate / aspartic acid / maleic acid terpolymer, and zinc salt are added sequentially to deionized water and mixed thoroughly to obtain the tetraphosphonic acid composite corrosion and scale inhibitor. The material consists of the following components: 1,4-phenylenebis(hydroxymethanetriyl)tetraphosphonic acid: 10-20%; sodium styrene sulfonate / aspartic acid / maleic acid terpolymer: 5-10%; zinc salt: 5-10%; the remainder is water.

[0026] The molecular formula of 1,4-phenylenebis(hydroxymethanetriyl)tetraphosphonic acid is C8H12H2O. 14 O 14 P4 is prepared by reacting terephthaloyl chloride and tris(trimethylsilane) phosphite and then hydrolyzing them. The specific method is as follows: terephthaloyl chloride is added to tris(trimethylsilane) phosphite and stirred at room temperature for 0.5-1 h. After the reaction is completed, methanol solution is added to the mixture and reacted at room temperature for 0.5-1.5 h. After rotary evaporation, (1,4-phenylenebis(hydroxymethanetriyl))tetraphosphonic acid is obtained.

[0027] Figure 1 This is the infrared spectrum of the compound (1,4-phenylenebis(hydroxymethanetriyl))tetraphosphonic acid. As can be seen from the figure, at 3419 cm⁻¹... -1 The point is the stretching vibration of OH, 1617 cm. -1 The point is the C=C stretching vibration in the benzene ring, 1374 cm⁻¹. -1 The point is the bending vibration of CH, 1176 cm. -1 The point is the stretching vibration of CO, and 975cm -1 The peak represents the stretching vibration of the phosphate group, and the above results demonstrate the successful synthesis of the (1,4-phenylenebis(hydroxymethanetriyl))tetraphosphonic acid compound.

[0028] Figure 2 This is the infrared spectrum of the prepared sodium styrene sulfonate / aspartic acid / maleic acid terpolymer. As can be seen from the figure, at 3136 cm⁻¹... -1 The point is the stretching vibration of the NH bond, 1578 cm⁻¹. -1 and 1399cm -1 The stretching vibrations at points C=O and CN in the amide bond, respectively, indicate that aspartic acid successfully polymerized with maleic acid. Furthermore, at 1600-1700 cm⁻¹... -1 No C=C bond peak was observed at this location, indicating that the C=C bonds in sodium styrene sulfonate and maleic acid broke and polymerized. (1137 cm⁻¹) -1 The presence of S=O bond stretching vibrations at this point indicates the presence of sulfonic acid groups in the polymerization product, suggesting that sodium styrene sulfonate participated in the copolymerization reaction. These results demonstrate the successful synthesis of the sodium styrene sulfonate / aspartic acid / maleic acid terpolymer.

[0029] Example 1: The preparation of 1,4-phenylenebis(hydroxymethanetriyl)tetraphosphonic acid compound includes: adding 27 mL of tris(trimethylsilane) phosphite to 4.0604 g of terephthaloyl chloride and stirring at room temperature (25 °C) for 0.5 h; then adding 40 mL of methanol solution to the mixture and continuing stirring for 1 h. After the reaction is complete, the (1,4-phenylenebis(hydroxymethanetriyl))tetraphosphonic acid compound is obtained by rotary evaporation.

[0030] Preparation of sodium styrene sulfonate / aspartic acid / maleic acid terpolymer: 11.6070 g of maleic acid, 9.9825 g of aspartic acid, and 15.4643 g of sodium styrene sulfonate were weighed and added to 65 mL of water. The mixture was stirred continuously at 90 °C, and sodium hydroxide was added to the reaction system until the pH reached approximately 9. 0.9128 g of ammonium persulfate was weighed, dissolved in 10 mL of water, and added to a constant-pressure dropping funnel. Under a nitrogen atmosphere, the ammonium persulfate solution was slowly added dropwise first, followed by the slow addition of sodium sulfite solution. After stirring continuously for 4 hours, the reaction was completed, yielding the sodium styrene sulfonate / aspartic acid / maleic acid terpolymer.

[0031] (1,4-phenylenebis(hydroxymethanetriyl))tetraphosphonic acid compound, sodium styrene sulfonate / aspartic acid / maleic acid terpolymer and zinc sulfate were added sequentially to deionized water and mixed evenly to obtain the above-mentioned composite corrosion and scale inhibitor.

[0032] In the composite corrosion and scale inhibitor, by weight, the amount of (1,4-phenylenebis(hydroxymethanetriyl))tetraphosphonic acid compound is 10 parts, the amount of sodium styrene sulfonate / aspartic acid / maleic acid terpolymer is 5 parts, the amount of zinc sulfate is 5 parts, and the amount of deionized water is 80 parts.

[0033] Example 2: The difference from Example 1 is that, in the composite corrosion and scale inhibitor, by weight, the amount of (1,4-phenylenebis(hydroxymethanetriyl))tetraphosphonic acid is 15 parts, the amount of sodium styrene sulfonate / aspartic acid / maleic acid terpolymer is 7.5 parts, the amount of zinc sulfate is 7.5 parts, and the amount of deionized water is 70 parts.

[0034] Example 3: The difference from Example 1 is that, in the composite corrosion and scale inhibitor, by weight, the amount of (1,4-phenylenebis(hydroxymethanetriyl))tetraphosphonic acid is 20 parts, the amount of sodium styrene sulfonate / aspartic acid / maleic acid terpolymer is 10 parts, the amount of zinc sulfate is 10 parts, and the amount of deionized water is 60 parts.

[0035] The corrosion inhibition performance of the composite corrosion and scale inhibitor disclosed in this invention was determined according to the standard GB / T18175-2014 "Determination of Corrosion Inhibition Performance of Water Treatment Agents - Rotary Coated Plate Method", and the scale inhibition performance was determined according to the standard GB / T 16632-2019 "Determination of Scale Inhibition Performance of Water Treatment Agents - Calcium Carbonate Deposition Method". The results are as follows: Figure 4 As shown, from Figure 4 Data shows that the composite corrosion and scale inhibitor prepared by the method disclosed in this application can achieve excellent corrosion and scale inhibition effects when applied to a circulating cooling water treatment system.

[0036] In summary, the (1,4-phenylene bis(hydroxymethanetriyl))tetraphosphonic acid compound developed in this invention exhibits significant advantages over traditional HEDP in terms of corrosion and scale inhibition performance in circulating water. Its molecular structure features four phosphonic acid groups bridged by rigid 1,4-phenylene groups, forming spatially symmetrical multidentate chelating sites, significantly enhancing its coordination ability compared to HEDP, effectively inhibiting the deposition of hydroxyapatite and iron oxides. Furthermore, the conjugation effect between the phosphonic acid groups and the benzene ring enhances the molecular thermal stability, thus avoiding secondary scaling problems caused by the high-temperature decomposition of HEDP. The phosphorus content of this compound is slightly lower than that of HEDP, which can alleviate eutrophication problems to some extent. Therefore, the novel (1,4-phenylene bis(hydroxymethanetriyl))tetraphosphonic acid corrosion and scale inhibitor provided by this invention not only overcomes many shortcomings of the traditional HEDP corrosion and scale inhibitor but also provides more effective and stable corrosion and scale inhibition performance under complex water quality and high-temperature conditions, possessing broad market prospects.

[0037] The above-described embodiments are merely preferred embodiments provided to fully illustrate the present invention, and the scope of protection of the present invention is not limited thereto. Equivalent substitutions or modifications made by those skilled in the art based on the present invention are all within the scope of protection of the present invention. The scope of protection of the present invention is defined by the claims.

Claims

1. A method for preparing a tetraphosphonic acid composite corrosion and scale inhibitor, characterized in that, (1,4-phenylenebis(hydroxymethanetriyl))tetraphosphonic acid, sodium styrene sulfonate / aspartic acid / maleic acid terpolymer and zinc salt are added sequentially to deionized water and mixed evenly to obtain a tetraphosphonic acid composite corrosion and scale inhibitor. The material is composed of the following components: (1,4-Phenylidenebis(hydroxymethanetriyl))tetraphosphonic acid: 10-20%; Sodium styrene sulfonate / aspartic acid / maleic acid terpolymer: 5-10%; Zinc salt: 5-10%; The rest is water.

2. The preparation method of the tetraphosphonic acid composite corrosion and scale inhibitor as described in claim 1, characterized in that, The molecular formula of the (1,4-phenylenebis(hydroxymethanetriyl))tetraphosphonic acid is C8H 14 O 14 P4 is prepared by reacting terephthaloyl chloride and tris(trimethylsilane) phosphite followed by hydrolysis; The specific method is as follows: Terephthaloyl chloride was added to tris(trimethylsilane) phosphite and stirred at room temperature for 0.5-1 h. After the reaction was completed, methanol solution was added to the mixture and reacted at room temperature for 0.5-1.5 h. After rotary evaporation, (1,4-phenylenebis(hydroxymethanetriyl))tetraphosphonic acid was obtained.

3. The preparation method of the tetraphosphonic acid composite corrosion and scale inhibitor as described in claim 1, characterized in that, The sodium styrene sulfonate / aspartic acid / maleic acid terpolymer is formed by copolymerization of sodium styrene sulfonate, aspartic acid and maleic acid under the action of an initiator. The mass ratio of maleic acid, aspartic acid, sodium styrene sulfonate and initiator is 1:(0.55-1.15):(0.08-0.18):(0.035-0.12).

4. The preparation method of the tetraphosphonic acid composite corrosion and scale inhibitor as described in claim 3, characterized in that, The initiator includes one or more of potassium persulfate, benzoyl peroxide, tert-butyl hydroperoxide, and isobutyl peroxide dicarbonate.

5. The preparation method of the tetraphosphonic acid composite corrosion and scale inhibitor as described in claim 1, characterized in that, The zinc salt includes one or more of zinc sulfate and zinc chloride.

6. A tetraphosphonic acid composite corrosion and scale inhibitor, characterized in that, It is obtained by the preparation method according to any one of claims 1-5.

7. The application of the tetraphosphonic acid composite corrosion and scale inhibitor as described in claim 6 in a circulating cooling water system.

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