A high-temperature resistant corrosion inhibitor suitable for various corrosion medium systems
By combining modified bisimizoline quaternary ammonium salt with Mannich base corrosion inhibitors, a corrosion inhibitor with multiple anchoring and hydrophobic barriers is formed, which solves the problem of poor performance of imidazoline corrosion inhibitors at high temperatures and achieves high-efficiency protection under various corrosive media.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- ZHEJIANG PROVINCE HANGHUA TECH CO LTD
- Filing Date
- 2026-02-11
- Publication Date
- 2026-06-23
AI Technical Summary
Existing imidazoline corrosion inhibitors have poor corrosion inhibition effects under high temperature conditions, and a single corrosion inhibitor cannot guarantee the stability of corrosion inhibition efficiency at different temperatures. In particular, in ethylene plants, they are easily affected by a variety of corrosive media, leading to severe equipment corrosion.
A 4'-tert-butyl-4-chlorobutyroylbenzene-modified bisimidazoline quaternary ammonium salt was used as the main corrosion inhibitor and combined with Mannich base synergistic corrosion inhibitors to form a dense adsorption film through multiple anchoring adsorption and hydrophobic barrier. The adsorption stability and protective effect were improved by combining surfactants.
It significantly improves corrosion inhibition performance in high-temperature environments, forms a complete and dense adsorption film, effectively isolates corrosive media, ensures long-term protection of equipment, and is suitable for various corrosive media systems.
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Abstract
Description
Technical Field
[0001] This invention relates to corrosion inhibitors, and more specifically to a high-temperature resistant corrosion inhibitor suitable for various corrosive media systems. Background Technology
[0002] During ethylene plant production, many pieces of equipment operate under harsh environmental conditions for extended periods, including dissolved oxygen, CO2, H2S, and other acidic soluble substances, as well as Cl-. - The coexistence of highly penetrating ions or other corrosive agents is quite common. Since chemical corrosion is difficult to completely avoid, this continuous damage gradually weakens the physical properties of equipment, causing malfunctions and, in severe cases, even disrupting the entire production process. Especially under high-temperature conditions, the accelerated chemical reaction rate, altered microstructure and mechanical properties of metallic materials, and potential softening, decomposition, or peeling of coatings further weaken the equipment's corrosion resistance and exacerbate the corrosion problem.
[0003] For example, in an ethylene plant, the main function of a dilution steam generator is to heat and vaporize process water from the bottom of the process water stripping tower into dilution steam, using quench oil as a heat source, to supply the cracking furnace unit. The operating temperature of the dilution steam generator is generally around 150-180℃, and it operates in a humid, high-temperature environment for extended periods. When the process water contains a certain amount of dissolved oxygen, acidic solubles (such as H2S, organic acids), or when unsaturated substances such as styrene polymerize or metal salts deposit, emulsification of the quench water can lead to oil contamination. This can cause hydrogen evolution corrosion on the surface of the dilution steam generator tube bundle, resulting in scaling and under-deposit corrosion, or uneven heat exchange creating localized thermal stress and ultimately, tube bundle leakage.
[0004] Currently, under conditions of multiple corrosive media coexisting at high temperatures, equipment corrosion can be inhibited through measures such as high-temperature resistant coatings, electrochemical protection, and the application of high-temperature corrosion inhibitors. The main problems with high-temperature resistant coatings are limited application conditions and easy peeling, while electrochemical protection is costly and difficult to scale up. Adding high-temperature corrosion inhibitors, however, is a simple, effective, and inexpensive chemical corrosion prevention method, widely used in ethylene plant production.
[0005] Currently, imidazoline-based corrosion inhibitors still constitute a large proportion of the corrosion inhibitors used. These inhibitors are nitrogen-containing five-membered heterocyclic compounds with double bonds on the heterocycle. These double bonds can form π-d bonds with metals, and the nitrogen atom can also form coordinate bonds with empty orbitals in the metal, allowing them to adsorb onto the metal surface and form a protective film to inhibit corrosion. However, the C=N single bonds within the imidazoline ring are easily broken under thermal conditions, causing the five-membered ring to open. This open-ring product differs from the original imidazoline in molecular size, polarity, and adsorption capacity, thus significantly reducing or even completely eliminating its "shielding" and "adsorption" functions as a corrosion inhibitor. Furthermore, the C=N double bond on the imidazoline ring is a relatively chemically reactive site, easily damaged under harsh environments. Due to the limitations of the imidazoline molecular structure, single imidazoline-based corrosion inhibitors cannot guarantee stable corrosion inhibition efficiency at different temperatures, especially exhibiting poor inhibition performance at high temperatures.
[0006] Therefore, a high-temperature corrosion inhibitor suitable for various corrosive media systems is proposed to address the above problems. The main component of this high-temperature corrosion inhibitor is a bis(tert-butyl-4-chlorobutyryl) quaternary ammonium salt compound modified with 4'-tert-butyl-4-chlorobutyrylbenzene. Its molecule has two imidazoline ring adsorption centers and two quaternary ammonium cation electrostatic adsorption centers, enabling it to firmly adsorb onto metal surfaces through multiple anchoring mechanisms. The introduced 4'-tert-butylphenyl hydrophobic group constructs a large physical barrier, effectively isolating dissolved oxygen, acidic solubles, and Cl-. - It can significantly improve the corrosion inhibition performance and high temperature resistance of the adsorption membrane in corrosive media.
[0007] To further enhance the protective effect of the adsorption film, the main agent is compounded with a Mannich base synergistic corrosion inhibitor. This synergistic corrosion inhibitor can form secondary adsorption through electrostatic adsorption and coordination bonding, filling the microscopic gaps in the main agent film layer. It can also stack with the main agent molecules, increasing the overall film thickness and density, ensuring the integrity and high efficiency of the adsorption film under high-temperature conditions. Furthermore, the addition of surfactants to the formulation reduces the interfacial tension between the metal surface and the corrosive medium, promoting the adsorption of the corrosion-inhibiting components on the metal surface, improving their solubility and dispersion stability, thereby increasing the corrosion inhibition rate. In summary, this high-temperature corrosion inhibitor ensures a long-lasting and highly efficient protective effect under harsh high-temperature corrosive environments through the combined effects of multiple adsorption processes, hydrophobic barriers, and synergistic film formation. Summary of the Invention
[0008] In view of the aforementioned technical problems, the present invention provides a high-temperature corrosion inhibitor suitable for various corrosive media systems. The high-temperature corrosion inhibitor includes a corrosion inhibitor main agent, which has a structure as shown in Formula I.
[0009] Formula I;
[0010] The corrosion inhibitor is obtained by the following preparation method:
[0011] Step (1): Azelaic acid is subjected to amidation and dehydration cyclization reaction with diethylenetriamine to obtain a diimidazoline intermediate;
[0012] Step (2): The bisimidazoline intermediate is subjected to a quaternization reaction with 4'-tert-butyl-4-chlorobutyrylbenzene to obtain the compound of formula I.
[0013] The corrosion inhibitor provided by this invention is a bisimidazoline skeleton constructed from azelaic acid and diethylenetriamine, possessing both two imidazoline ring chemisorption centers and two quaternary ammonium cation electrostatic adsorption centers. This enables multiple anchoring adsorption on the metal surface, significantly improving adsorption stability and temperature resistance. Furthermore, modification with 4'-tert-butyl-4-chlorobutyroylbenzene allows this group to align vertically or obliquely on the metal surface, forming a hydrophobic protective umbrella that effectively isolates dissolved oxygen, acidic solubles, and Cl-. - Corrosive media provide a strong spatial barrier, thereby greatly enhancing the density and physical isolation effect of the adsorption membrane.
[0014] In some embodiments, in step (1), the molar ratio of azelaic acid to diethylenetriamine is 1:2-2.4; the amidation reaction temperature is 130-160°C; the dehydration cyclization reaction temperature is 180-220°C; and the reaction time is 2-4 hours.
[0015] In some embodiments, in step (2), the molar ratio of the bisimidazoline intermediate to 4'-tert-butyl-4-chlorobutyrobenzoylbenzene is 1:2-2.5; the reaction temperature is 100-120°C; and the reaction time is 1-3 hours.
[0016] In some embodiments, the components include the following parts by weight:
[0017] 5-35 parts of corrosion inhibitor;
[0018] 5-15 parts of Mannich base synergistic corrosion inhibitor;
[0019] 5-20 parts of surfactant;
[0020] Solvent: 5-35 parts.
[0021] This invention combines a high-temperature corrosion inhibitor with a synergistic corrosion inhibitor. The latter can form secondary adsorption through electrostatic adsorption and coordination bonding, filling the microscopic gaps in the main agent film. It can also stack with the main agent molecules, increasing the overall film thickness and density, ensuring the integrity and efficiency of the adsorption film under high-temperature conditions. Adding a surfactant can reduce the interfacial tension between the metal surface and the corrosive medium, promoting the adsorption of the high-temperature corrosion inhibitor and synergistic corrosion inhibitor on the metal surface, improving their solubility and dispersion stability, thereby increasing the corrosion inhibition rate.
[0022] In some embodiments, the synergistic corrosion inhibitor is a Mannich base compound.
[0023] The amine element in the Mannich base molecules provided by this invention can react with H in the corrosive medium. + The combination process causes the Mannich base molecules to acquire a charge, which then adheres to the metal surface through electrostatic attraction. Simultaneously, the Mannich base molecule contains multiple adsorption centers with lone pairs of electrons, acting as a chelating ligand. When in contact with the metal, its oxygen and nitrogen atoms have strong electron-donating capabilities, and the lone pairs of electrons readily enter the hybridized dsp empty orbitals of the iron atom (ion), forming a stable chelate with a ring structure through coordination. This chelate can form a dense adsorption film on the metal surface, preventing corrosion products such as Fe from adsorbing onto the metal. 3+ Diffusion into the solution and H in the solution + It migrates towards the metal. In addition, the benzene ring on the molecule has delocalized large π bonds, and the electron cloud of the π bond can complex with the iron group and adsorb onto the metal surface.
[0024] In some embodiments, the Mannich base compound is a compound having a structure as shown in Formula II and / or Formula III.
[0025] Formula II;
[0026] Formula III.
[0027] In some embodiments, the surfactant is commercially available fatty alcohol polyoxyethylene ether AEO-20 or nonylphenol polyoxyethylene ether TX.
[0028] In some embodiments, the solvent is deionized water.
[0029] In some embodiments, the compound having the structure shown in Formula II or Formula III is obtained by the following preparation method: the synthesis method of the Mannich base synergistic corrosion inhibitor includes the following steps: in the presence of a solvent, benzylamine or n-octylaniline, formaldehyde and acetophenone are subjected to a Mannich reaction in the presence of an acidic catalyst, and after the reaction is completed, the Mannich base synergistic corrosion inhibitor is obtained by separation and purification.
[0030] Secondly, the present invention provides a corrosion inhibitor having a structure as shown in Formula I.
[0031] Compared with the prior art, the present invention has the following beneficial effects:
[0032] (1) This invention provides a high-temperature corrosion inhibitor suitable for various corrosive media systems, wherein the main corrosion inhibitor is a 4'-tert-butyl-4-chlorobutyrylbenzene modified bis-imidazoline quaternary ammonium salt compound. Compared with mono-imidazoline compounds, this molecule achieves multiple anchoring and strong adsorption on the metal matrix through two imidazoline rings (chemisorption centers) and two quaternary ammonium cations (electrostatic adsorption centers), and has stronger anti-erosion ability, thereby significantly enhancing the temperature stability of the imidazoline ring. At the same time, the introduced "4'-tert-butylphenyl" hydrophobic group can construct a huge hydrophobic barrier above the adsorption layer, effectively blocking the erosion of dissolved oxygen, acidic solubles and Cl⁻ and other corrosive media, further strengthening the adsorption and protective effect of the corrosion inhibitor on the metal matrix.
[0033] (2) Due to the large steric hindrance, the modified bisimidazoline quaternary ammonium salt molecule is prone to insufficient film density when formed alone. To address this, the present invention combines a high-temperature corrosion inhibitor with a Mannich base synergistic corrosion inhibitor. This synergistic corrosion inhibitor can form secondary adsorption on the metal substrate surface through electrostatic adsorption and coordination bonding, effectively filling the microscopic gaps between the main agent molecules and improving the density of the adsorption film. At the same time, its synergistic stacking with the main agent molecules on the metal substrate can increase the overall film thickness, thereby ensuring the integrity and high efficiency of the adsorption film under high-temperature conditions. In addition, by further compounding with suitable surfactants and solvents, the solubility and dispersion stability of the corrosion inhibition system in the medium are improved, ensuring its uniform action and long-term performance under complex working conditions.
[0034] (3) The preparation process of this high temperature corrosion inhibitor is simple, and the corrosion inhibition effect is good. It is suitable for inhibiting high temperature corrosion in various corrosive media systems and can still maintain good corrosion inhibition effect in high temperature environment (150-180℃). Detailed Implementation
[0035] The technical solution of the present invention will be further described below with reference to the embodiments, but the scope of protection of the present invention is not limited thereto.
[0036] Synthesis of corrosion inhibitor:
[0037] The high-temperature corrosion inhibitor in the following examples is synthesized as follows:
[0038] S1: Azelaic acid and diethylenetriamine were subjected to an amidation reaction at 140°C, wherein the molar ratio of azelaic acid to diethylenetriamine was 1:2.2. Then, the temperature was increased to 200°C for a dehydration cyclization reaction for 2 hours to obtain a diimidazoline intermediate.
[0039] S2: After cooling the above reaction system to 100℃, add 4'-tert-butyl-4-chlorobutyroylbenzene and continue the reaction for 2 hours, wherein the molar ratio of the bisimidazoline intermediate to 4'-tert-butyl-4-chlorobutyroylbenzene is 1:2.3, to obtain the 4'-tert-butyl-4-chlorobutyroylbenzene modified bisimidazoline quaternary ammonium salt high-temperature corrosion inhibitor.
[0040] Synthesis of compound II:
[0041] Formula II
[0042] Preparation method: 30 mL of anhydrous ethanol and 30 mL of benzylamine were added to a three-necked flask equipped with a thermometer, a serpentine condenser, a water bath, and a stirrer. The temperature was raised to 70 °C, and 45 mL of formaldehyde was added under stirring. The reaction was allowed to proceed for 2 h. Concentrated hydrochloric acid was slowly added dropwise until the pH of the solution reached 2. Then, 30 mL of acetophenone was added, and the reaction was allowed to proceed for 10 h. The mixture was cooled to room temperature to obtain the preliminary synthesized product. The water bath was heated to 65 °C, and the preliminary synthesized product was added to a distillation flask. Vacuum distillation was performed under reduced pressure at 80 kPa until no bubbles appeared in the distillation flask and no liquid droplets appeared at the condenser, thus obtaining the compound with the structure shown in Formula II.
[0043] Synthesis of Compound III:
[0044] Formula III.
[0045] Preparation method: 30 mL of anhydrous ethanol and 30 mL of n-octylaniline were added to a three-necked flask equipped with a thermometer, a serpentine condenser, a water bath, and a stirrer. The temperature was raised to 70 °C, and 45 mL of formaldehyde was added under stirring. The reaction was allowed to proceed for 2 h. Concentrated hydrochloric acid was slowly added dropwise until the pH of the solution reached 2. Then, 30 mL of acetophenone was added, and the reaction was allowed to proceed for 10 h. The mixture was cooled to room temperature to obtain the preliminary synthesized product. The water bath was heated to 65 °C, and the preliminary synthesized product was added to a distillation flask. Vacuum distillation was performed under reduced pressure at 80 kPa until no bubbles appeared in the distillation flask and no liquid droplets appeared at the condenser, thus obtaining the compound with the structure shown in Formula III.
[0046] Example 1
[0047] 15g of high-temperature corrosion inhibitor, 5g of synergistic corrosion inhibitor, 10g of AEO-20, and 25g of deionized water were sequentially added to a three-necked flask equipped with a stirrer and a thermometer. The synergistic corrosion inhibitor was a Mannich base compound with formula II. The mixture was stirred at 60°C for 1 hour until homogeneous, resulting in a high-temperature corrosion inhibitor suitable for various corrosive media systems.
[0048] Example 2
[0049] 20g of high-temperature corrosion inhibitor, 10g of synergistic corrosion inhibitor, 15g of AEO-20, and 30g of deionized water were sequentially added to a three-necked flask equipped with a stirrer and a thermometer. The synergistic corrosion inhibitor was a Mannich base compound with the formula III structure. The mixture was stirred at 60°C for 1 hour until homogeneous, resulting in a high-temperature corrosion inhibitor suitable for various corrosive media systems.
[0050] Example 3
[0051] 25g of high-temperature corrosion inhibitor, 15g of synergistic corrosion inhibitor, 20g of AEO-20, and 35g of deionized water were sequentially added to a three-necked flask equipped with a stirrer and a thermometer. The synergistic corrosion inhibitor was a Mannich base compound with the formula III structure. The mixture was stirred at 60°C for 1 hour until homogeneous, yielding a high-temperature corrosion inhibitor suitable for various corrosive media systems.
[0052] Example 4
[0053] The difference from Example 1 is that the surfactant used is TX-8.
[0054] Example 5
[0055] The difference compared to Example 1 is that the mass ratio of the high-temperature corrosion inhibitor, the synergistic corrosion inhibitor, AEO-20 and deionized water is 20:10:15:30.
[0056] Example 6
[0057] The difference from Example 1 is that the synergistic corrosion inhibitor is a Mannich base compound having the structure of Formula III.
[0058] Example 7
[0059] The difference compared to Example 2 is that the mass ratio of the high-temperature corrosion inhibitor, the synergistic corrosion inhibitor, AEO-20 and deionized water is 25:15:20:35.
[0060] Comparative Example 1
[0061] Only add the diimidazolin intermediate obtained in step S1.
[0062] Comparative Example 2
[0063] Only high-temperature corrosion inhibitor is added.
[0064] Comparative Example 3
[0065] The difference compared to Example 1 is that no synergistic corrosion inhibitor was added.
[0066] Comparative Example 4
[0067] The difference compared to Example 1 is that AEO-20 was not added.
[0068] Comparative Example 5
[0069] Only add a synergistic corrosion inhibitor with the structure shown in Formula II.
[0070] Comparative Example 6
[0071] Only add a synergistic corrosion inhibitor with the structure shown in Formula III.
[0072] Experimental Example
[0073] To evaluate the corrosion inhibition effect of the high-temperature corrosion inhibitor of the present invention in various corrosive media systems, the high-temperature corrosion inhibitors of the blank group, Examples 1-7, and Comparative Examples 1-6 were evaluated by the weight loss method of the coated sample.
[0074] Corrosion inhibition performance evaluation: 20# steel was selected as the test plate. After sanding to remove the blemishes and burrs, the plate was cleaned with a soft brush in petroleum ether to remove the oil stains. Then, it was soaked in anhydrous ethanol for about 1 minute, then taken out and dried with cold air or air-dried. It was placed in a desiccator and weighed after constant weight.
[0075] Acidic water from an ethylene plant was used as the corrosive medium, containing 100 mg / L CO2, 50 mg / L H2S, 10 mg / L acetic acid, and 5 mg / L chloride ions. 100 ppm of the solutions from Examples 1-7 and Comparative Examples 1-6 of this invention were added to this acidic water. Three test strips were used in each group, ensuring that the entire surface of the strips was in contact with the medium and that the strips did not touch the inner wall of the container. The test medium was then heated to 180°C and held at that temperature for 72 hours. After the power was cut off, the strips were removed and immediately rinsed with water, then brushed with a soft brush. Finally, each strip was washed with acetone and anhydrous ethanol, placed on clean filter paper, dried with cold air, and then dried in a desiccator for 20 minutes before being weighed.
[0076] The corrosion inhibition effect of high-temperature corrosion inhibitors can be expressed by the corrosion inhibition rate η:
[0077] v= 100%
[0078] In the formula: m0 - Weight loss of blank test sample, g; m1 - Weight loss of the tablets after the addition test, in g.
[0079] The corrosion inhibition performance evaluation experimental data of Examples 1-7 and Comparative Examples 1-6 are shown in Table 1.
[0080] Table 1. Experimental results of corrosion inhibition performance
[0081] corrosion inhibitor Test temperature (°C) Corrosion inhibitor concentration (mg / Kg) Mean weight loss (g) Corrosion inhibition rate (%) Blank group 180 0 0.0211 - Example 1 180 100 0.0022 89.7 Example 2 180 100 0.0013 94.0 Example 3 180 100 0.0012 94.3 Example 4 180 100 0.0023 89.0 Example 5 180 100 0.0015 92.8 Example 6 180 100 0.0019 91.2 Example 7 180 100 0.0008 96.2 Comparative Example 1 180 100 0.0072 65.7 Comparative Example 2 180 100 0.0037 82.6 Comparative Example 3 180 100 0.0050 76.1 Comparative Example 4 180 100 0.0046 78.4 Comparative Example 5 180 100 0.0084 60.2 Comparative Example 6 180 100 0.0080 62.3
[0082] As can be seen from the data in Table 1, the high-temperature corrosion inhibitor provided by this invention exhibits excellent corrosion inhibition performance in complex corrosive media at 180℃. The corrosion inhibition rate of all embodiments is higher than 89%, and the corrosion inhibition rate of the preferred formulation can reach 96.2%. This proves that the corrosion inhibitor can effectively inhibit the synergistic erosion of multiple corrosive media at high temperatures.
[0083] Performance comparison analysis further revealed the synergistic mechanism of the present invention: First, structural modification significantly improved the performance of the core agent; the corrosion inhibition rate of the 4'-tert-butyl-4-chlorobutyrylbenzene-modified bisimidazoline quaternary ammonium salt compound (82.6%) was much higher than that of the unmodified intermediate (Comparative Example 1, 65.7%). More importantly, in the complete formulation of Example 1, the actual effective concentration of the core agent was only about 27.3 ppm, but its corrosion inhibition rate (89.7%) was higher than that of Comparative Example 2 (82.6%), which used 100 ppm of pure agent. This proves that the Mannich base synergist and surfactant have a multiplier effect, enabling a lower dose of agent to exert a better protective effect. In addition, under conditions of similar agent concentration (about 30-33 ppm), the performance of systems lacking Mannich base (Comparative Example 3, 76.1%) or surfactant (Comparative Example 4, 78.4%) was significantly lower than that of the complete compound system. However, the corrosion inhibition ability of Mannich base components used alone is limited (comparative examples 5-6, about 60%), which further highlights the synergistic effect achieved by the present invention, which takes the modified main agent as the core and achieves synergistic effect through compounding.
[0084] The corrosion inhibitor of this invention does not contain elements such as phosphorus that are harmful to the environment. While ensuring excellent high-temperature corrosion inhibition performance, it is also more environmentally friendly and will not affect the normal operation of the equipment or the quality of chemical products.
Claims
1. A high-temperature corrosion inhibitor suitable for various corrosive media systems, characterized in that, The corrosion inhibitor includes a corrosion inhibitory main agent, the structural formula of which is shown in Figure I: Formula I; The preparation method of the corrosion inhibitor includes the following steps: Step (1): Azelaic acid is subjected to amidation and dehydration cyclization reaction with diethylenetriamine to obtain a diimidazoline intermediate; Step (2): The bisimidazoline intermediate is subjected to a quaternization reaction with 4'-tert-butyl-4-chlorobutyrylbenzene to obtain the compound of formula I.
2. The high-temperature corrosion inhibitor according to claim 1, characterized in that, In step (1), the molar ratio of azelaic acid to diethylenetriamine is 1:2-2.4; the amidation reaction temperature is 130-160℃; the dehydration cyclization reaction temperature is 180-220℃; and the reaction time is 2-4 hours.
3. The high-temperature corrosion inhibitor according to claim 1, characterized in that, In step (2), the molar ratio of the bisimizoline intermediate to 4'-tert-butyl-4-chlorobutyrobenzoylbenzene is 1:2-2.5; the reaction temperature is 100-120℃; and the reaction time is 1-3 hours.
4. The high-temperature corrosion inhibitor according to claim 1, characterized in that, Components comprising the following parts by weight: 5-35 parts of corrosion inhibitor; 5-15 parts of Mannich base synergistic corrosion inhibitor; 5-20 parts of surfactant; Solvent: 5-35 parts.
5. The high-temperature corrosion inhibitor according to claim 4, characterized in that, The synergistic corrosion inhibitor is a Mannich base compound.
6. The high-temperature corrosion inhibitor according to claim 5, characterized in that, The Mannich base compounds are compounds having structures as shown in Formula II and / or Formula III. Formula II; Formula III.
7. The high-temperature corrosion inhibitor according to claim 1, characterized in that, The surfactant is commercially available fatty alcohol polyoxyethylene ether AEO-20 or nonylphenol polyoxyethylene ether TX-8.
8. The high-temperature corrosion inhibitor according to claim 1, characterized in that, The solvent is deionized water.
9. The high-temperature corrosion inhibitor according to claim 6, characterized in that, The synthesis method of the Mannich base synergistic corrosion inhibitor includes the following steps: in the presence of a solvent, benzylamine or n-octylaniline, formaldehyde and acetophenone undergo a Mannich reaction under the action of an acidic catalyst, and after the reaction is completed, the Mannich base synergistic corrosion inhibitor is obtained by separation and purification.
10. A corrosion inhibitor, characterized in that, The corrosion inhibitor has the structure shown in Formula I: Formula I.