A phenylimidazole-terminated polyethylene glycol corrosion-inhibiting and antibacterial water treatment agent and its preparation method

Abstract

A phenylimidazolium-terminated polyethylene glycol (PEG) corrosion inhibitor and antibacterial water treatment agent and its preparation method are disclosed, comprising the following steps: Step 1: dissolving polyethylene glycol and triethylamine in an anhydrous solvent and cooling the solution to form a reaction system; Step 2: slowly adding bromoacetyl bromide to the reaction system and continuing the reaction to obtain a reaction solution; Step 3: diluting the reaction solution with dichloromethane, removing the triethylamine salt, bromoacetyl bromide, and triethylamine by water extraction, and evaporating after extraction to neutrality to obtain a bromoacetyl-terminated PEG intermediate; Step 4: mixing the intermediate with 1-phenylimidazolium and heating to react to obtain a crude product; Step 5: after the reaction is completed, cooling to room temperature, dialysis in ethanol to purify the product and recover unreacted 1-phenylimidazolium, and evaporating the dialysate to remove ethanol to obtain the phenylimidazolium-terminated PEG corrosion inhibitor and antibacterial water treatment agent. This invention achieves the polymerization, water solubility, and composite functionalization of imidazoline corrosion inhibitors.

Description

Technical Field

[0001] This invention belongs to the field of water treatment technology, specifically relating to a phenylimidazole-terminated polyethylene glycol corrosion inhibitor and antibacterial water treatment agent and its preparation method. Background Technology

[0002] For closed or circulating systems, adding corrosion inhibitors to the circulating water medium is considered an economical and effective method to suppress corrosion. For example, in industrial pickling, crude oil fracturing, crude oil extraction water injection pressurization, industrial circulation, and cooling, a certain amount of corrosion inhibitor can be added to the system to inhibit the corrosion of pipelines and equipment by the fluid. In recent years, with the continuous improvement of the performance requirements of corrosion inhibitors in application fields, some corrosion inhibitor products with high inhibition rates and wide applicability have been developed, such as imidazoline corrosion inhibitors. However, facing the new requirements of the water treatment market for water-based, polymer-based, and multifunctional corrosion inhibitor products, imidazoline corrosion inhibitors are gradually showing their shortcomings.

[0003] First, the imidazoline structure has poor water solubility, which limits its use in circulating water or cooling water systems.

[0004] Secondly, because current imidazoline corrosion inhibitors are all small molecule compounds, the adsorption film on metal surfaces is not dense enough during application, leading to volatilization and environmental pollution at high temperatures. Furthermore, most of the substituents on the imidazoline ring in current products are straight-chain hydrocarbons. Introducing aromatics would be beneficial for further improving corrosion inhibition performance, but due to limitations in synthesis technology, there is currently a lack of publicly available products on this topic. Moreover, the introduction of aromatic rings further reduces the water solubility of imidazoline, posing a new challenge to its water solubility. In addition, current imidazoline corrosion inhibitors do not possess any other functions besides corrosion inhibition.

[0005] For example, Chinese patent CN107385450A discloses a polyethylene glycol oleic acid imidazoline corrosion inhibitor and its preparation method, which solves the problems of water solubility and polymerization, but does not solve the shortcomings of substituent aromatic cyclization and composite functionalization. Summary of the Invention

[0006] In order to overcome the problems existing in the prior art, the purpose of this invention is to provide a phenyl imidazole-terminated polyethylene glycol corrosion inhibitor and antibacterial water treatment agent and its preparation method. This water treatment agent realizes the high molecular weight and water solubility of imidazole corrosion inhibitors, and at the same time, it has a composite function of antibacterial properties, which has extremely high application value in the field of industrial water treatment.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0008] A phenylimidazole-terminated polyethylene glycol corrosion inhibitor and antibacterial water treatment agent, the corrosion inhibitor and antibacterial water treatment agent having the following chemical structure;

[0009]

[0010] Where: n is greater than 9 and is an integer.

[0011] Furthermore, the corrosion-inhibiting and antibacterial water treatment agent has dual functions of corrosion inhibition and antibacterial action. The terminal phenyl imidazole group contains a large number of lone pairs of electrons, which occupy the 3d empty orbitals of the metal atom, achieving strong adsorption on the metal surface, isolating the corrosive medium, and playing a corrosion-inhibiting role. The quaternary ammonium salt group on the imidazole ring can destroy the membrane permeability of bacteria, thus inhibiting bacteria.

[0012] Furthermore, the corrosion-inhibiting and antibacterial water treatment agent is obtained by reacting bromoacetate-terminated polyethylene glycol with 1-phenylimidazole in a solvent-free state.

[0013] A method for preparing a phenylimidazole-terminated polyethylene glycol corrosion inhibitor and antibacterial water treatment agent specifically includes the following steps:

[0014] Step 1: Dissolve polyethylene glycol and triethylamine in an anhydrous solvent to obtain a solution, and cool the solution to form a reaction system; the role of triethylamine is to neutralize the hydrochloric acid produced by the reaction of polyethylene glycol and bromoacetyl bromide, thereby promoting the reaction to move in the forward direction;

[0015] Step 2: Slowly add bromoacetyl bromide dropwise to the above reaction system. After the addition is complete, move the reaction system to room temperature and continue the reaction to obtain the reaction solution.

[0016] Step 3: Dilute the above reaction solution with dichloromethane, remove the byproduct triethylamine salt generated during the neutralization of triethylamine, as well as the unreacted bromoacetyl bromide and triethylamine by water extraction, and after extraction to neutrality, evaporate (40°C) to remove the solvent to obtain the bromoacetyl-terminated polyethylene glycol intermediate.

[0017] Step 4: Mix the bromoacetate-terminated polyethylene glycol intermediate with 1-phenylimidazole, heat to 80~110 ℃, and continue the reaction for 6~24 h to obtain the crude product of phenylimidazole-terminated polyethylene glycol corrosion inhibitor and antibacterial water treatment agent.

[0018] Step 5: After the reaction is complete, cool to room temperature, dissolve the crude product of phenylimidazolium-terminated polyethylene glycol corrosion inhibitor and antibacterial water treatment agent in ethanol, dialyze in ethanol (molecular weight cutoff 500) to purify the product and recover unreacted 1-phenylimidazolium, and after evaporating the dialysate to remove ethanol, the phenylimidazolium-terminated polyethylene glycol corrosion inhibitor and antibacterial water treatment agent is obtained.

[0019] Further, in step 1, the anhydrous solvent is any one or a combination of two of dichloromethane, tetrahydrofuran, toluene, and N,N-dimethylformamide; the solution is cooled to 0 °C.

[0020] Furthermore, in step 1, the molar ratio of triethylamine to polyethylene glycol is 3~2.2:1. The amount of triethylamine added is slightly higher than the stoichiometric ratio in the chemical reaction formula, ensuring that the hydrochloric acid generated from the reaction of polyethylene glycol and bromoacetyl bromide is completely neutralized, promoting the reaction towards the forward direction. If the amount of triethylamine is less than the stoichiometric ratio, the hydrochloric acid generated from the reaction of polyethylene glycol and bromoacetyl bromide cannot be completely neutralized, inhibiting the reaction from moving towards the forward direction. If the amount of triethylamine is too large, it will result in raw material waste and reduced economic efficiency.

[0021] Furthermore, in step 2, the molar ratio of bromoacetyl bromide to polyethylene glycol is 3~2.2:1; the reaction continues at room temperature for 6~24 h. The amount of bromoacetyl bromide added is slightly higher than the stoichiometric ratio in the chemical reaction formula to ensure that the hydroxyl groups at both ends of polyethylene glycol are completely reacted. If the amount added is less than the stoichiometric ratio in the chemical reaction formula, the hydroxyl groups at the ends of polyethylene glycol cannot be completely reacted, and the target product cannot be obtained; while if the amount added is too large, it will result in waste of raw materials and reduced economic efficiency.

[0022] Furthermore, in step 4, the molar ratio of the bromoacetate-terminated polyethylene glycol intermediate to 1-phenylimidazole is 1:2.4~3. The amount of 1-phenylimidazole added is slightly higher than the stoichiometric ratio in the chemical reaction formula, ensuring that the ends of the bromoacetate-terminated polyethylene glycol are completely reacted, and any excess 1-phenylimidazole raw material is recycled. If the amount added is less than the stoichiometric ratio in the chemical reaction formula, the end groups of the bromoacetate-terminated polyethylene glycol cannot be completely reacted; while an excessive amount will cause difficulties in the subsequent recycling process.

[0023] The beneficial effects of this invention are:

[0024] (1) While ensuring the water solubility and polymerization of imidazoline corrosion inhibitors, aromatic ring groups are introduced. Because aromatic ring groups have a large number of lone pairs of electrons, they can occupy the empty 3d orbitals of metal atoms, thereby enhancing adsorption on the metal surface and maximizing the isolation of corrosive media, further improving corrosion inhibition performance. Cationic groups are also introduced, as cationic quaternary ammonium salt groups can disrupt the membrane permeability of bacteria, thereby killing them. Therefore, this water treatment agent is endowed with antibacterial function. The water treatment product proposed in this invention achieves a combined function of corrosion inhibition and antibacterial activity.

[0025] (2) The preparation method of the corrosion-inhibiting and antibacterial water treatment agent provided by the invention is simple and efficient. The reaction between bromoacetate-terminated polyethylene glycol and 1-phenylimidazole is carried out in a solvent-free state, which is in line with the development concept of green chemistry. Attached Figure Description

[0026] Figure 1 This is the synthetic reaction formula for the corrosion-inhibiting and antibacterial water treatment agent proposed in this invention.

[0027] Figure 2Infrared spectra of polyethylene glycol, bromoacetate-terminated polyethylene glycol intermediates, and phenylimidazole-terminated polyethylene glycol corrosion inhibitors and antibacterial water treatment agents.

[0028] Figure 3 The images show the 1H NMR spectra of polyethylene glycol, bromoacetate-terminated polyethylene glycol intermediates, and phenylimidazolium-terminated polyethylene glycol corrosion inhibitors and antibacterial water treatment agents.

[0029] Figure 4 The polarization curves of carbon steel with the product as a corrosion inhibitor were obtained by way of examples and comparative examples.

[0030] Figure 5 Electrochemical impedance curves of carbon steel with the product as a corrosion inhibitor were obtained using examples and comparative examples.

[0031] Figure 6 The image shows the inhibitory and antibacterial water treatment agent prepared in Example 1 on Escherichia coli. Detailed Implementation

[0032] The present invention will now be described in further detail with reference to the accompanying drawings.

[0033] Example 1

[0034] This embodiment provides a phenylimidazolium-terminated polyethylene glycol corrosion inhibitor and antibacterial water treatment agent, which is obtained by the following preparation method:

[0035] (1) Take 6 g of polyethylene glycol (M n =600 g / mol, 0.01 mol) and 2.23 g (0.022 mol) of triethylamine were dissolved in anhydrous dichloromethane, and the solution was cooled to 0 °C;

[0036] (2) Slowly add 2.48 g (0.022 mol) of bromoacetyl bromide to the above reaction system. After the addition is complete, move the reaction system to room temperature and continue the reaction for 6 h.

[0037] (3) After the reaction is complete, the above reaction solution is diluted with dichloromethane, and the generated byproduct triethylamine salt, as well as the unreacted bromoacetyl bromide and triethylamine are removed by water extraction. After extraction to neutrality, the solvent is evaporated to obtain the bromoacetyl-terminated polyethylene glycol intermediate.

[0038] (4) The above bromoacetate-terminated polyethylene glycol intermediate was mixed with 3.46 g (0.024 mol) of 1-phenylimidazole and heated to 110 °C for 6 h.

[0039] (5) After the reaction is completed, the mixture is cooled to room temperature, the crude product is dissolved in ethanol, and the product is purified by dialyzing in ethanol (with a molecular weight cutoff of 500) and the unreacted 1-phenylimidazole is recovered. After the ethanol is removed by evaporation of the dialysate, the phenylimidazole-terminated polyethylene glycol corrosion inhibitor and antibacterial water treatment agent is obtained.

[0040] The product obtained through this embodiment has the following chemical structure.

[0041] .

[0042] Example 2

[0043] This embodiment provides a phenylimidazolium-terminated polyethylene glycol corrosion inhibitor and antibacterial water treatment agent, which is obtained by the following preparation method:

[0044] (1) Take 20 g of polyethylene glycol (M n =2000 g / mol, 0.01 mol) and 2.63 g (0.026 mol) of triethylamine were dissolved in a mixed solvent of anhydrous tetrahydrofuran, and the solution was cooled to 0 °C;

[0045] (2) Slowly add 2.94 g (0.026 mol) of bromoacetyl bromide to the above reaction system. After the addition is complete, move the reaction system to room temperature and continue the reaction for 12 h.

[0046] (3) After the reaction is complete, the above reaction solution is diluted with dichloromethane, and the generated byproduct triethylamine salt, as well as the unreacted bromoacetyl bromide and triethylamine are removed by water extraction. After extraction to neutrality, the solvent is evaporated to obtain the bromoacetyl-terminated polyethylene glycol intermediate.

[0047] (4) The above bromoacetate-terminated polyethylene glycol intermediate was mixed with 4.32 g (0.03 mol) of 1-phenylimidazole and heated to 80 °C for 24 h.

[0048] (5) After the reaction is completed, the mixture is cooled to room temperature, the crude product is dissolved in ethanol, and the product is purified by dialyzing in ethanol (with a molecular weight cutoff of 500) and the unreacted 1-phenylimidazole is recovered. After the ethanol is removed by evaporation of the dialysate, the phenylimidazole-terminated polyethylene glycol corrosion inhibitor and antibacterial water treatment agent is obtained.

[0049] The product obtained through this embodiment has the following chemical structure;

[0050] .

[0051] Example 3

[0052] This embodiment provides a phenylimidazolium-terminated polyethylene glycol corrosion inhibitor and antibacterial water treatment agent, which is obtained by the following preparation method:

[0053] (1) Take 50 g of polyethylene glycol (M n =5000 g / mol, 0.01 mol) and 3.04 g (0.03 mol) of triethylamine were dissolved in a mixed solvent of anhydrous tetrahydrofuran, and the solution was cooled to 0 °C;

[0054] (2) Slowly add 3.39 g (0.03 mol) of bromoacetyl bromide to the above reaction system. After the addition is complete, move the reaction system to room temperature and continue the reaction for 24 h.

[0055] (3) After the reaction is complete, the above reaction solution is diluted with dichloromethane, and the generated byproduct triethylamine salt, as well as the unreacted bromoacetyl bromide and triethylamine are removed by water extraction. After extraction to neutrality, the solvent is evaporated to obtain the bromoacetyl-terminated polyethylene glycol intermediate.

[0056] (4) The above bromoacetate-terminated polyethylene glycol intermediate was mixed with 4.32 g (0.03 mol) of 1-phenylimidazole and heated to 110 °C for 24 h.

[0057] (5) After the reaction is completed, the mixture is cooled to room temperature, the crude product is dissolved in ethanol, and the product is purified by dialyzing in ethanol (with a molecular weight cutoff of 500) and the unreacted 1-phenylimidazole is recovered. After the ethanol is removed by evaporation of the dialysate, the phenylimidazole-terminated polyethylene glycol corrosion inhibitor and antibacterial water treatment agent is obtained.

[0058] The product obtained through this embodiment has the following chemical structure.

[0059] .

[0060] Example 4

[0061] This embodiment provides a phenylimidazolium-terminated polyethylene glycol corrosion inhibitor and antibacterial water treatment agent, which is obtained by the following preparation method:

[0062] (1) Take 6 g of polyethylene glycol (M n =600 g / mol, 0.01 mol) and 2.23 g (0.022 mol) of triethylamine were dissolved in toluene, and the solution was cooled to 0 °C;

[0063] (2) Slowly add 2.48 g (0.022 mol) of bromoacetyl bromide to the above reaction system. After the addition is complete, move the reaction system to room temperature and continue the reaction for 6 h.

[0064] (3) After the reaction is complete, the above reaction solution is diluted with dichloromethane, and the generated byproduct triethylamine salt, as well as the unreacted bromoacetyl bromide and triethylamine are removed by water extraction. After extraction to neutrality, the solvent is evaporated to obtain the bromoacetyl-terminated polyethylene glycol intermediate.

[0065] (4) The above bromoacetate-terminated polyethylene glycol intermediate was mixed with 3.74 g (0.026 mol) of 1-phenylimidazole and heated to 100 °C for 24 h.

[0066] (5) After the reaction is completed, the mixture is cooled to room temperature, the crude product is dissolved in ethanol, and the product is purified by dialyzing in ethanol (with a molecular weight cutoff of 500) and the unreacted 1-phenylimidazole is recovered. After the ethanol is removed by evaporation of the dialysate, the phenylimidazole-terminated polyethylene glycol corrosion inhibitor and antibacterial water treatment agent is obtained.

[0067] The product obtained through this embodiment has the following chemical structure.

[0068] .

[0069] Example 5

[0070] This embodiment provides a phenylimidazolium-terminated polyethylene glycol corrosion inhibitor and antibacterial water treatment agent, which is obtained by the following preparation method:

[0071] (1) Add 4.5 g of polyethylene glycol (M n =450 g / mol, 0.01 mol) and 2.23 g (0.022 mol) of triethylamine were dissolved in a mixed solvent of anhydrous dichloromethane and N,N-dimethylformamide, and the solution was cooled to 0 °C;

[0072] (2) Slowly add 2.48 g (0.022 mol) of bromoacetyl bromide to the above reaction system. After the addition is complete, move the reaction system to room temperature and continue the reaction for 15 h.

[0073] (3) After the reaction is complete, the above reaction solution is diluted with dichloromethane, and the generated byproduct triethylamine salt, as well as the unreacted bromoacetyl bromide and triethylamine are removed by water extraction. After extraction to neutrality, the solvent is evaporated to obtain the bromoacetyl-terminated polyethylene glycol intermediate.

[0074] (4) The above bromoacetate-terminated polyethylene glycol intermediate was mixed with 4.32 g (0.03 mol) of 1-phenylimidazole and heated to 110 °C for 15 h.

[0075] (5) After the reaction is completed, the mixture is cooled to room temperature, the crude product is dissolved in ethanol, and the product is purified by dialyzing in ethanol (with a molecular weight cutoff of 500) and the unreacted 1-phenylimidazole is recovered. After the ethanol is removed by evaporation of the dialysate, the phenylimidazole-terminated polyethylene glycol corrosion inhibitor and antibacterial water treatment agent is obtained.

[0076] The product obtained through this embodiment has the following chemical structure.

[0077] .

[0078] Comparative Example 1

[0079] The only difference from Example 1 is that imidazole is used instead of 1-phenylimidazole in step 4 of Example 1, while the other raw materials and preparation methods are the same as in Example 1.

[0080] The product obtained through this comparative example has the following chemical structure.

[0081] .

[0082] Comparative Example 2

[0083] The only difference from Example 1 is that hexylimidazole is used instead of 1-phenylimidazole in step 4 of Example 1, while the other raw materials and preparation methods are the same as in Example 1.

[0084] The product obtained through this comparative example has the following chemical structure.

[0085] .

[0086] Comparative Example 3

[0087] The only difference from Example 1 is that bromoacetyl bromide is not added in step 2; the other raw materials and preparation methods are the same as in Example 1.

[0088] The product obtained through this comparative example has the following chemical structure.

[0089] .

[0090] Structural characterization

[0091] Fourier transform infrared absorption spectroscopy (FT-IR) was used to verify the skeletal structures of the polyethylene glycol raw material, the bromoacetate-terminated polyethylene glycol intermediate, and the phenylimidazolium-terminated polyethylene glycol corrosion inhibitor and antibacterial water treatment agent final product in Example 1. The instrument used was a VERTEX-80 FT-IR spectrometer from Bruker GmbH, Germany. The test scanning range was 4000 cm⁻¹. -1 —500 cm -1 Samples were prepared using the coating method.

[0092] Using nuclear magnetic resonance hydrogen spectroscopy (NMR) 1 The structures of the polyethylene glycol raw material, the bromoacetate-terminated polyethylene glycol intermediate, and the phenylimidazolium-terminated polyethylene glycol corrosion inhibitor and antibacterial water treatment agent final product in Example 1 were verified by 1H-NMR. Deuterated chloroform was used as the solvent, and TMS was used as the internal standard.

[0093] The FT-IR spectra of the polyethylene glycol raw material, the bromoacetate-terminated polyethylene glycol intermediate, and the phenylimidazolium-terminated polyethylene glycol corrosion inhibitor and antibacterial water treatment agent final product in Example 1 are as follows: Figure 2 As shown in the figure, the FT-IR spectrum of polyethylene glycol is at 1102 cm⁻¹. -1 It exhibits characteristic absorption due to ether bond stretching vibrations. Compared to polyethylene glycol, the bromoacetate-terminated polyethylene glycol intermediate shows absorption at 1740 cm⁻¹. -1 A distinct ester-characteristic absorption peak appeared at 1560 cm⁻¹, confirming the successful acylation reaction of the terminal hydroxyl group in the polyethylene glycol structure with bromoacetyl bromide. In the FT-IR spectrum of the phenylimidazolium-terminated polyethylene glycol final product, the peak at 1560 cm⁻¹ is [missing value]. -1 The characteristic absorption of the imidazole ring appeared at 650-900 cm⁻¹. -1 The characteristic absorption peak of the benzene ring bending vibration was detected, confirming the successful introduction of the phenylimidazolium group into both ends of the polyethylene glycol.

[0094] In Example 1, the polyethylene glycol raw material, the bromoacetate-terminated polyethylene glycol intermediate, and the phenylimidazolium-terminated polyethylene glycol corrosion inhibitor and antibacterial water treatment agent final product... 1 H NMR spectrum as shown Figure 3 As shown.

[0095] Figure 3 In (a), the proton peak at δ=3.62 represents the chemical shift of the methylene group in the polyethylene glycol unit. Figure 3 In (b), chemical shifts of the methylene group connected to oxygen at the end of the polyethylene glycol unit and the methylene group in the bromoacetate group can be detected at δ=3.88 and 4.33, respectively, confirming that the terminal hydroxyl group of polyethylene glycol is modified to a bromoacetate group. Figure 3 In (c), chemical shifts of protons in the phenylimidazolium terminal group were observed at δ=7.3~8.

[0096] In summary, Figure 1 and Figure 2 It has been confirmed that the phenylimidazole-terminated polyethylene glycol corrosion inhibitor and antibacterial water treatment agent can be successfully obtained according to the technical solution provided by the present invention.

[0097] Performance testing:

[0098] (1) Evaluation of corrosion inhibition performance using the static weight loss method:

[0099] The corrosion inhibition performance of the corrosion inhibitor and antibacterial water treatment agent was evaluated according to GB / T 18175-2014 "Determination of Corrosion Inhibition Performance of Water Treatment Agents - Rotary Plating Method". The corrosive medium was a 1 mol / L HCl solution, and the experimental metal material was Q235 low carbon steel.

[0100] The corrosion inhibition rates of different samples are shown in Table 1. As can be seen from Table 1, all examples and comparative examples showed varying degrees of corrosion inhibition. Items 1-3 show that the corrosion inhibition rate of the corrosion-inhibiting and antibacterial water treatment agent obtained in Example 1 continuously increased with increasing concentration. This is because its adsorption on the metal surface became more dense with increasing concentration, enhancing the protective effect on the metal surface. Items 3-7 show that, at the same concentration, the corrosion inhibition performance of the corrosion-inhibiting and antibacterial water treatment agent decreased with the increase in the length of the intermediate polyethylene glycol segment. This is because with the increase in the length of the polyethylene glycol segment, the water solubility of the corrosion-inhibiting and antibacterial water treatment agent increases, and more molecules tend to dissolve in water rather than adsorb on the metal surface, leading to a decrease in the product's corrosion inhibition performance.

[0101] Products in Items 3 and 8 have polyethylene glycol intermediate segments of the same length, while the product obtained in Example 1 (Item 3) has phenyl imidazole end groups, and Comparative Example 1 (Item 8) has imidazole end groups. Example 1 performs better than Comparative Example 1 at the same concentration. This demonstrates that adding phenyl substituents to the end groups further enhances the corrosion inhibition performance of the corrosion-inhibiting and antibacterial water treatment agent.

[0102] Products from Items 3 and 9 have polyethylene glycol intermediate segments of the same length, while the product obtained in Example 1 (Item 3) has a phenyl imidazole end group, and Comparative Example 2 (Item 9) has a hexyl imidazole end group. Example 1 performs better than Comparative Example 2 at the same concentration. This demonstrates that phenyl substituents can further enhance corrosion inhibition performance compared to alkyl substituents with the same number of carbon atoms.

[0103] Products from Items 3 and 10 have polyethylene glycol intermediate segments of the same length, while the product obtained in Example 1 (Item 3) has phenylimidazolium end groups, and Comparative Example 3 (Item 10) has hydroxyl end groups. Example 1 shows significantly better performance than Comparative Example 3 at the same concentration. This demonstrates the importance of the terminal phenylimidazolium functional groups in improving the corrosion inhibition performance of the product.

[0104] Table 1

[0105] entry sample Dosage (mg / L) Corrosion inhibition rate (%) 1 Example 1 50 97.46% 2 Example 1 100 97.71% 3 Example 1 150 98.10% 4 Example 2 150 94.96% 5 Example 3 150 93.61% 6 Example 4 150 97.98% 7 Example 5 150 98.39% 8 Comparative Example 1 150 96.26% 9 Comparative Example 2 150 96.65% 10 Comparative Example 3 150 67.02%

[0106] (2) Evaluation of corrosion inhibition performance by electrochemical method:

[0107] The corrosion inhibition performance of the corrosion-inhibiting and antibacterial water treatment agent was verified using a Shanghai Chenhua CHI660E electrochemical workstation. A three-electrode system was employed, with the working electrode, reference electrode, and counter electrode being a Q235 steel sheet, a saturated calomel electrode, and a platinum electrode, respectively. The corrosive medium remained a 1 mol / L HCl solution. The open-circuit voltage (OCP) test time was 1200 s, and the electrochemical impedance spectroscopy (EIS) test frequency range was 100 kHz to 0.01 Hz with an amplitude of 5 mV. The polarization curve scan rate was 1 mV / s, ranging from OCP ± 250 mV. The corrosion inhibition rate was calculated based on the corrosion current density in the polarization curve and the charge transfer resistance in the EIS spectrum.

[0108] The polarization curves and electrochemical impedance spectroscopy obtained from the electrochemical tests are as follows: Figure 4 and Figure 5 As shown, the corrosion inhibition rates calculated based on corrosion current density and charge transfer resistance are listed in Tables 2 and 3, respectively. Although the corrosion inhibition rate data obtained by electrochemical testing differs from those obtained by static weight loss method due to different testing principles, the performance of Examples 1 and 2 is significantly better than that of the comparative examples.

[0109] It is evident that the proposed corrosion-inhibiting and antibacterial water treatment agent achieves superior corrosion inhibition effects through innovative design of the product's chemical structure.

[0110] Table 2

[0111]

[0112] Table 3

[0113]

[0114] (3) Evaluation of antibacterial properties:

[0115] The specific evaluation methods are as follows: The solid culture medium was prepared according to standard methods using 8 g trypsin, 5 g yeast extract, 10 g sodium chloride, 30 g agar powder, and 1000 ml distilled water. The liquid culture medium was prepared using 1 g trypsin, 0.5 g yeast extract, 2 g sodium chloride solution, and 100 ml distilled water, and sterilized at 121 °C for 20 min. Before the antibacterial experiment, 25 mg of the corrosion-inhibiting and antibacterial water treatment agent obtained in Example 4 was dissolved in 1 mL of DMF in an EP tube. 20 μL of the corrosion-inhibiting and antibacterial water treatment agent solution was mixed evenly with 30 μL of bacterial suspension, and 10 μL of the mixture was transferred to the solid culture medium. The mixture was evenly spread on the surface of the solid culture medium using a scraper and then transferred to a 21 °C incubator for constant temperature incubation. After 12 h, the colony morphology was observed and recorded.

[0116] Figure 6The results showed that after 12 hours, obvious bacterial colonies were observed in the blank control group, while no colonies were observed in the experimental group. This confirms that the corrosion-inhibiting and antibacterial water treatment agent proposed in this invention has antibacterial function.

Claims

1. A phenylimidazole-terminated polyethylene glycol corrosion inhibitor and antibacterial water treatment agent, characterized in that, Corrosion-inhibiting and antibacterial water treatment agents have the following chemical structures; Where: n is greater than 9 and is an integer.

2. The phenylimidazolium-terminated polyethylene glycol corrosion inhibitor and antibacterial water treatment agent according to claim 1, characterized in that, The corrosion-inhibiting and antibacterial water treatment agent is obtained by reacting bromoacetate-terminated polyethylene glycol with 1-phenylimidazole in a solvent-free state.

3. The method for preparing a phenylimidazolium-terminated polyethylene glycol corrosion inhibitor and antibacterial water treatment agent according to any one of claims 1 or 2, characterized in that, The specific steps include: Step 1: Dissolve polyethylene glycol and triethylamine in an anhydrous solvent to obtain a solution, and cool the solution to 0 °C to form a reaction system; Step 2: Slowly add bromoacetyl bromide dropwise to the above reaction system. After the addition is complete, move the reaction system to room temperature and continue the reaction to obtain the reaction solution. Step 3: Dilute the above reaction solution with dichloromethane, remove the byproduct triethylamine salt generated during the neutralization of triethylamine, as well as the unreacted bromoacetyl bromide and triethylamine by water extraction, extract until neutral, evaporate to remove the solvent, and obtain the bromoacetyl-terminated polyethylene glycol intermediate. Step 4: Mix the bromoacetate-terminated polyethylene glycol intermediate with 1-phenylimidazole, heat to 80~110℃, and continue the reaction for 6~24 h to obtain the crude product of phenylimidazole-terminated polyethylene glycol corrosion inhibitor and antibacterial water treatment agent. Step 5: After the reaction is complete, cool to room temperature, dissolve the crude product of phenylimidazolium-terminated polyethylene glycol corrosion inhibitor and antibacterial water treatment agent in ethanol, dialyze the product in ethanol to purify it and recover the unreacted 1-phenylimidazolium, and evaporate the dialysate to remove the ethanol to obtain the phenylimidazolium-terminated polyethylene glycol corrosion inhibitor and antibacterial water treatment agent.

4. The preparation method of the phenylimidazolium-terminated polyethylene glycol corrosion inhibitor and antibacterial water treatment agent according to claim 3, characterized in that, In step 1, the anhydrous solvent is any one or a combination of two of dichloromethane, tetrahydrofuran, toluene, and N,N-dimethylformamide.

5. The preparation method of a phenylimidazolium-terminated polyethylene glycol corrosion inhibitor and antibacterial water treatment agent according to claim 3, characterized in that, In step 1, the molar ratio of triethylamine to polyethylene glycol is 3~2.2:

1.

6. The preparation method of the phenylimidazolium-terminated polyethylene glycol corrosion inhibitor and antibacterial water treatment agent according to claim 3, characterized in that, In step 2, the molar ratio of bromoacetyl bromide to polyethylene glycol is 3~2.2:1; the reaction continues at room temperature for 6~24 h.

7. The preparation method of the phenylimidazolium-terminated polyethylene glycol corrosion inhibitor and antibacterial water treatment agent according to claim 3, characterized in that, In step 4, the molar ratio of bromoacetate-terminated polyethylene glycol intermediate to 1-phenylimidazole is 1:2.4~3.

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