阅读说明：本技术 一种含杂环三嗪基季铵盐及其制备和应用 (Quaternary ammonium salt containing heterocyclic triazine group and preparation and application thereof ) 是由 朱海林 刘建华 王俊霞 李晓芬 陆小猛 冯丽 马雪梅 胡志勇 于 2021-08-19 设计创作，主要内容包括：本发明涉及一种含杂环三嗪基季铵盐,具有以下通式(I)表示的结构：其中R为C-(4-10)烷基；X为─NH─或─S─；Y为带有硫醚基或亚氨基连接基团的含氮和/或硫芳香杂环。本发明通过同一分子内杂环与季铵盐官能团的协同耦合效应,使其在使用量较少时即可具有较高的缓蚀杀菌效率,可以作为缓蚀剂应用,特别是用于硫酸盐还原菌存在下的碳钢的缓蚀杀菌处理。(The invention relates to a heterocycle-containing triazinyl quaternary ammonium salt, which has a structure represented by the following general formula (I): wherein R is C 4‑10 An alkyl group; x is-NH-or-S-; y is a nitrogen and/or sulfur containing aromatic heterocycle with a thioether or imino linking group. The invention has the advantages that through the synergistic coupling effect of the heterocyclic ring and the quaternary ammonium salt functional group in the same molecule, the corrosion inhibition and sterilization efficiency can be higher when the usage amount is less, and the corrosion inhibition and sterilization agent can be used as a corrosion inhibitor, and is particularly used for the corrosion inhibition and sterilization treatment of carbon steel in the presence of sulfate reducing bacteria.)

1. A heterocycle-containing triazinyl quaternary ammonium salt having a structure represented by the general formula (I):

wherein:

r is C_4-10An alkyl group; x is-NH-or-S-; y is a nitrogen and/or sulfur containing aromatic heterocycle with a thioether or imino linking group.

2. The heterocycle-containing triazinyl quaternary ammonium salt of claim 1 wherein Y is、Or。

3. A method for producing the heterocyclic triazinyl-containing quaternary ammonium salt according to claim 1 or 2, comprising:

cyanuric chloride is used as raw material, and C is represented by general formula RXH_4-10Reacting alkyl aliphatic amine or alkyl mercaptan to obtain a compound represented by a general formula (II);

then the compound represented by the general formula (II) reacts with a sulfhydryl or amino substituted nitrogen and/or sulfur aromatic heterocyclic compound represented by the general formula YH to obtain a compound represented by the general formula (III);

reacting the compound represented by the general formula (III) with N, N-dimethyl-1, 3-propane diamine to obtain a compound represented by a general formula (IV);

finally, the compound represented by the general formula (IV) reacts with bromoethane to prepare the quaternary ammonium salt containing the heterocyclic triazinyl represented by the general formula (I).

4. The method for preparing the quaternary ammonium salt containing heterocyclic triazinyl according to claim 3, wherein the mercapto or amino substituted nitrogen-and/or sulfur-containing aromatic heterocyclic compound represented by formula YH is 2-mercaptobenzothiazole, 2-aminobenzimidazole or 2-mercapto-5-methyl-1, 3, 4-thiadiazole.

5. The method for preparing the heterocycle-containing triazinyl quaternary ammonium salt according to claim 3, comprising the steps of:

1) in a solvent toluene system in the presence of sodium hydroxide or sodium carbonate acid-binding agent, cyanuric chloride and C represented by a general formula RXH_4-10Reacting alkyl aliphatic amine or alkyl mercaptan under ice bath condition to precipitate a white solid of a compound represented by a general formula (II) from a reaction solution;

2) dissolving the compound represented by the general formula (II) by acetone, adding an acetone-water mixed solution of a sulfydryl or amino substituted nitrogen-containing and/or sulfur-containing aromatic heterocyclic compound represented by the general formula YH, and reacting at 45-50 ℃ to obtain a compound represented by the general formula (III) as a light yellow solid;

3) gradually adding the compound represented by the general formula (III) into N, N-dimethyl-1, 3-propane diamine, heating to 30 ℃ for reaction, and precipitating a compound represented by the general formula (IV) into a reaction solution to obtain a light yellow or white solid;

4) and adding a compound represented by a general formula (IV) and bromoethane into acetonitrile serving as a solvent, and reacting at 50-60 ℃ to prepare a target product of the compound represented by the general formula (I).

6. Use of the heterocyclic triazinyl quaternary ammonium salts according to claim 1 as corrosion inhibitors.

7. Use of the heterocyclic triazinyl quaternary ammonium salt according to claim 1 as a corrosion inhibitor for inhibiting corrosion by sulfate-reducing bacteria.

8. The use of the heterocyclic triazinyl quaternary ammonium salt of claim 1 as a sulfate-reducing bacteria fungicide.

9. The use of the heterocyclic triazinyl quaternary ammonium salt of claim 1 as a corrosion-inhibiting bactericide for carbon steel in the presence of sulfate-reducing bacteria.

Technical Field

The invention belongs to the technical field of metal corrosion and protection, and relates to a quaternary ammonium salt corrosion inhibition bactericide, in particular to a heterocyclic triazine group-containing quaternary ammonium salt corrosion inhibition bactericide and application thereof in inhibiting corrosion of sulfate reducing bacteria.

Background

Microbial corrosion (MIC) refers to a phenomenon in which corrosion of a metal material is directly accelerated due to the self-life activities of microorganisms or indirectly accelerated through metabolites thereof. According to statistics, the economic loss caused by metal corrosion accounts for about 3-5% of GDP annually, wherein the economic loss caused by microbial corrosion accounts for about 20% of the total economic loss (Chinese academy for corrosion and protection, 2021, 41(1): 1-12.).

The microorganisms involved in MIC mainly include Sulfate Reducing Bacteria (SRB), Iron-oxidizing bacteria (IOB), Iron-reducing bacteria (IRB), Acid-producing bacteria (APB), and the like. It was investigated that in the known MIC case, SRB exists and participates in half of it. Thus, SRB is the major species responsible for microbial corrosion.

For a long time, the most common method for controlling microbial corrosion has been the addition of biocides, which kill microorganisms and inhibit microbial corrosion. However, after a period of use, the bacteria develop resistance to the chemicals, so that the amount and cost of the bactericide used are increased, which imposes economic and environmental burdens. On the other hand, bactericides are effective against planktonic microorganisms, but are difficult to kill microorganisms in biofilms. Therefore, it is necessary to design a high-efficiency corrosion-inhibiting bactericide against SRB corrosion and reduce the usage amount of the bactericide.

The quaternary ammonium salt surfactant has bacteriostatic and bactericidal functions, low toxicity and wide application range, and has a long history in research on the quaternary ammonium salt surfactant as a bactericide. Meanwhile, the quaternary ammonium salt surfactant can form directional adsorption on an interface, can form a compact protective film, slows down the corrosion of metal, and can also be used as a metal corrosion inhibitor.

However, it was found (Corroson Science, 2017, 117: 24-34.) that SRB can still be locally adsorbed on the surface of the material to form a biofilm when the mass concentration of dimethylammonium chloride (alkyl chain length 10-16) is 40mg/L, and obvious local Corrosion pits still exist in the area where the biofilm is formed.

The heterocyclic compound generally contains a heteroatom (such as N, S, O and the like) with larger electronegativity in molecules, can provide lone pair electrons to form a coordination bond with the surface of the metal, and prevents corrosion reaction; secondly, the heterocyclic compound mostly has a pi bond and can act with the metal surface through a front line molecular orbit to prevent further corrosion reaction; in addition, the polarity of the molecules can cover the metal surface through electrostatic attraction, so that the corrosion process of the metal is inhibited. Thus, heterocyclic compounds are commonly used corrosion inhibitors in industry, but have relatively poor antimicrobial properties against microorganisms.

Disclosure of Invention

The invention aims to provide a heterocycle-containing triazinyl quaternary ammonium salt, which has higher corrosion inhibition and sterilization efficiency when the usage amount is less through the synergistic coupling effect of heterocycles and quaternary ammonium salt functional groups in the same molecule.

The quaternary ammonium salt containing heterocyclic triazinyl has a structure represented by a general formula (I):

wherein:

r is C_4-10An alkyl group; x is-NH-or-S-; y is a nitrogen and/or sulfur containing aromatic heterocycle with a thioether or imino linking group.

Further, wherein Y is preferably、Or。

The heterocyclic triazinyl-containing quaternary ammonium salt represented by the general formula (I) of the present invention can be produced by the following method.

Cyanuric chloride is used as raw material, and C is represented by general formula RXH_4-10And (3) reacting alkyl aliphatic amine or alkyl mercaptan to obtain the compound represented by the general formula (II).

And then reacting the compound represented by the general formula (II) with a mercapto or amino substituted nitrogen and/or sulfur containing aromatic heterocyclic compound represented by the general formula YH to obtain a compound represented by the general formula (III).

The compound represented by the general formula (III) is further reacted with N, N-dimethyl-1, 3-propanediamine to obtain a compound represented by the general formula (IV).

And finally, reacting the compound shown in the general formula (IV) with bromoethane to prepare the quaternary ammonium salt containing the heterocyclic triazinyl shown in the general formula (I).

Further, the following provides a specific synthetic route of the method for producing the heterocyclic triazinyl-containing quaternary ammonium salt represented by the above general formula (I).

Among them, the mercapto or amino substituted nitrogen and/or sulfur containing aromatic heterocyclic compound represented by general formula YH is preferably any one of 2-mercaptobenzothiazole, 2-aminobenzimidazole and 2-mercapto-5-methyl-1, 3, 4-thiadiazole.

Furthermore, the invention provides a more detailed preparation method of the heterocycle-containing triazinyl quaternary ammonium salt.

1) In a solvent toluene system in the presence of sodium hydroxide or sodium carbonate acid-binding agent, cyanuric chloride and C represented by a general formula RXH_4-10The alkyl aliphatic amine or alkyl mercaptan reacts under ice-bath conditions to precipitate a white solid of the compound represented by the general formula (II).

2) Dissolving the compound represented by the general formula (II) by acetone, adding an acetone-water mixed solution of a sulfydryl or amino substituted nitrogen and/or sulfur aromatic heterocyclic compound represented by the general formula YH, and reacting at 45-50 ℃ to obtain a compound represented by the general formula (III) as a light yellow solid.

3) Gradually adding the compound represented by the general formula (III) into N, N-dimethyl-1, 3-propane diamine, heating to 30 ℃ for reaction, and precipitating the compound represented by the general formula (IV) from the reaction solution to obtain a light yellow or white solid.

4) And adding a compound represented by a general formula (IV) and bromoethane into acetonitrile serving as a solvent, and reacting at 50-60 ℃ to prepare a target product of the compound represented by the general formula (I).

The invention also provides application of the heterocyclic triazine-based quaternary ammonium salt as a corrosion inhibitor.

Specifically, the invention provides application of the heterocycle-containing triazinyl quaternary ammonium salt as a corrosion inhibitor for inhibiting corrosion of sulfate reducing bacteria.

The invention also provides application of the heterocyclic triazine-based quaternary ammonium salt as a bactericide against sulfate reducing bacteria.

More specifically, the invention provides application of the heterocycle-containing triazinyl quaternary ammonium salt as a slow-release bactericide for carbon steel in the presence of sulfate reducing bacteria.

The molecular structure of the heterocyclic triazinyl quaternary ammonium salt contains an alkane chain, a heterocycle and a quaternary ammonium salt structure. The quaternary ammonium salt can be selectively adsorbed on the surface of a biomembrane of the SRB and permeates into the biomembrane, so that the biological functions of the biomembrane such as electron transfer, selective substance transfer, isolation barrier and the like are changed, the permselectivity and the genetic system of the biomembrane are damaged, and the activity of the SRB is inhibited or even killed; on the other hand, triazine rings and heterocycles in the molecular structure have rich heteroatoms (N, S) and share pi electrons, and can form coordination bonds with empty d orbitals of iron for chemical adsorption, so that the corrosion inhibition and sterilization performance of the quaternary ammonium salt surfactant and the heterocyclic compound can be further improved through the synergistic effect of the quaternary ammonium salt surfactant and the heterocyclic compound.

Meanwhile, an alkyl chain contained in the structure of the compound can form a layer of hydrophobic barrier, so that aggressive ions are prevented from invading, and carbon steel is protected from being corroded.

Therefore, the heterocyclic triazine-based quaternary ammonium salt based on the structure has higher corrosion inhibition and sterilization performance under the condition of less using amount. Compared with the commonly used quaternary ammonium salt bactericide 1227, the efficiency of inhibiting the activity of sulfate reducing bacteria by the heterocyclic triazine-containing quaternary ammonium salt is higher.

Drawings

FIG. 1 is an infrared spectrum of the heterocyclic triazinyl-containing quaternary ammonium salt BTOTB prepared in example 1.

FIG. 2 is an ESI-MS spectrum of example 1 for the preparation of heterocyclic triazinyl-containing quaternary ammonium salt BTOTB.

FIG. 3 is an infrared spectrum of MTOTB containing heterocyclic triazinyl quaternary ammonium salt prepared in example 2.

FIG. 4 is an ESI-MS spectrum of example 2 for the preparation of MTOTB containing a heterocyclic triazinyl quaternary ammonium salt.

FIG. 5 is a graph of surface tension versus concentration for BTOTB and MTOTB.

Fig. 6 is a graph showing the effect of the static weightlessness test.

FIG. 7 is a Nyquist plot of carbon steel soaked in SRB-containing simulated seawater without and with 0.1mM different corrosion inhibitors for different days, respectively; in the figure: (a) SRB, (b), BTOTB, (c), MTOTB, (d), 1227.

FIG. 8 is a surface SEM image of a carbon steel sample after being soaked in different corrosion media for 21 d; in the figure: (a) polished carbon steel, (b), SRB, (c), 0.1mM MTOTB, (d), 1227.

Detailed Description

The following detailed description of embodiments of the present invention is provided in connection with the accompanying drawings and examples. The following examples are only for more clearly explaining the technical solutions of the present invention so as to enable those skilled in the art to well understand and utilize the present invention, and do not limit the scope of protection of the present invention.

The names and the abbreviations of the experimental methods, production processes, instruments and equipment related to the embodiments of the present invention are all conventional names in the art, and are clear and definite in the related fields of use, and those skilled in the art can understand the conventional process steps and apply the corresponding equipment according to the names, and implement the process according to the conventional conditions or the conditions suggested by the manufacturers.

The raw materials and reagents used in the examples of the present invention are not particularly limited in terms of their sources, and are all conventional products commercially available. They may also be prepared according to conventional methods well known to those skilled in the art.

Example 1: synthesis of the quaternary ammonium salt (I) containing heterocyclic triazinyl.

9.25g (0.05 mol) of cyanuric chloride and 100mL of toluene are placed in a 250mL four-neck flask and stirred until all the substances are dissolvedAfter completion, 7.10g (0.055 mol) of n-octylamine was added under ice-bath conditions, at a concentration of 1mol/L Na₂CO₃And adjusting the pH value of the reaction solution to 8-9 by using the solution to carry out reaction.

Thin layer chromatography (silica gel GF)₂₅₄Toluene: methanol = 1: 1, v/v) monitor the reaction to completion.

After the reaction is finished, filtering, and sequentially using 1mol/L hydrochloric acid and 0.5mol/L NaHCO to filtrate₃Washing the organic layer with distilled water to neutrality, collecting the organic layer, drying with anhydrous sodium sulfate, vacuum filtering, and concentrating under reduced pressure to obtain white solid OT.

Adding 2.80g (0.01 mol) of the white solid OT and 100mL of acetone into a 250mL four-neck flask, heating to 45-50 ℃ under stirring, after the white solid is completely dissolved, dropwise adding a mixed solution of 1.85g (0.011 mol) of 2-mercaptobenzothiazole dissolved in acetone and water = 2: 1 (v/v) into the four-neck flask, and stirring at 45-50 ℃ for reaction.

Thin layer chromatography (silica gel GF)₂₅₄Petroleum ether: acetone = 3: 1, v/v) to monitor the reaction to completion.

After the reaction, distilled water was added to the reaction solution to precipitate a large amount of pale yellow solid BTOT, which was washed with hot acetone and then dried in vacuum.

30mL of N, N-dimethyl-1, 3-propanediamine was put into a 250mL three-necked flask equipped with a mechanical stirrer, and 2.05g (0.005 mol) of BTOT was added in portions to carry out a reaction while maintaining the reaction temperature at 30 ℃.

Thin layer chromatography (silica gel GF)₂₅₄Acetone to toluene to water = 6: 1: 0.5, v/v/v) to monitor the reaction to completion.

The reaction solution was dissolved in 100mL of toluene, transferred to a separatory funnel, and washed with saturated NaCl several times to neutrality. The organic layer was collected, dried over anhydrous sodium sulfate, filtered under suction, and concentrated under reduced pressure to give a pale yellow/colorless oil, which was then placed in a fume hood to precipitate a pale yellow or white solid BTOTN.

0.50g (0.001 mol) of BTOTN, 0.16g (0.0015 mol) of bromoethane and 100mL of acetonitrile were weighed into a 250mL three-necked flask equipped with a reflux condenser, and the reaction was carried out while stirring at 60 ℃ while maintaining the reaction temperature.

Thin layer chromatography (silica gel GF)₂₅₄Acetone to toluene to water = 6: 1, v/v/v) to monitor the reaction to completion.

And (3) concentrating the reaction solution under reduced pressure to remove the solvent and unreacted raw materials to obtain a light yellow crude product, and recrystallizing with acetone to obtain the target product, namely the heterocyclic-quaternary ammonium salt surfactant BTOTB.

According to the infrared spectrogram in figure 1 and the high-resolution mass spectrogram in figure 2, structural characterization is carried out on the target product, and the target product containing the heterocyclic triazinyl quaternary ammonium salt (I) with the structure in the embodiment is finally prepared.

Example 2: and (3) synthesizing the quaternary ammonium salt (II) containing the heterocyclic triazinyl.

2.80g (0.01 mol) of the white solid OT of example 1 and 100mL of acetone were added to a 250mL four-necked flask, and the mixture was heated to 45 to 50 ℃ with stirring, and after the white solid was completely dissolved, a mixed solution of 1.45g (0.011 mol) of 2-mercapto-5-methyl-1, 3, 4-thiadiazole in acetone and water = 2: 1 (v/v) was added dropwise to the four-necked flask, and the temperature was maintained at 45 to 50 ℃ and the reaction was carried out with stirring.

Thin layer chromatography (silica gel GF)₂₅₄Petroleum ether: acetone = 3: 1, v/v) to monitor the reaction to completion.

After the reaction, distilled water was added to the reaction solution to precipitate a large amount of MTOT as a pale yellow solid, which was washed with hot acetone and then dried in vacuum.

30mL of N, N-dimethyl-1, 3-propanediamine was put into a 250mL three-necked flask equipped with a mechanical stirring device, and 1.90g (0.005 mol) of MTOT was added in portions to carry out a reaction while maintaining the reaction temperature at 30 ℃.

Thin layer chromatography (silica gel GF)₂₅₄Acetone to toluene to water = 6: 1: 0.5, v/v/v) to monitor the reaction to completion.

The reaction solution was dissolved in 100mL of toluene, transferred to a separatory funnel, and washed with saturated NaCl several times to neutrality. Collecting organic layer, drying with anhydrous sodium sulfate, vacuum filtering, concentrating under reduced pressure to obtain yellowish/colorless oily substance, and placing the oily substance in fume hood to separate out yellowish or white solid MTOTN.

0.45g (0.001 mol) of MTOTN, 0.16g (0.0015 mol) of bromoethane and 100mL of acetonitrile were weighed into a 250mL three-necked flask equipped with a reflux condenser, and the reaction was carried out while stirring at 60 ℃ while maintaining the reaction temperature.

Thin layer chromatography (silica gel GF)₂₅₄Acetone to toluene to water = 6: 1, v/v/v) to monitor the reaction to completion.

And (3) concentrating the reaction solution under reduced pressure to remove the solvent and unreacted raw materials to obtain a light yellow crude product, and recrystallizing with acetone to obtain the target product, namely the heterocyclic-quaternary ammonium salt surfactant MTOTB.

According to the infrared spectrogram of fig. 3 and the high-resolution mass spectrogram of fig. 4, structural characterization is carried out on the target product, which proves that the target product containing the heterocyclic triazinyl quaternary ammonium salt (ii) with the structure of the embodiment is finally prepared.

Example 3: and (3) measuring the surface activity of the quaternary ammonium salt containing the heterocyclic triazinyl.

In this example, the surface activity of the quaternary ammonium salt containing heterocyclic triazinyl prepared in examples 1 and 2 in simulated seawater was measured by a surface tension method.

SRB medium components were added to a 3.5% NaCl aqueous solution to simulate a seawater environment. The SRB culture medium comprises the following components (g/L): k₂HPO₄ 0.5，NH₄Cl 1.0，Na₂SO₄ 1.0，CaCl₂·2H₂O 0.1，MgSO₄·7H₂O2.0, DL-sodium lactate 2.0 and yeast extract 1.0.

A series of heterocyclic triazine-based quaternary ammonium salt solutions with different concentrations are prepared by using the simulated seawater, and the equilibrium surface tension of the heterocyclic triazine-based quaternary ammonium salt is measured by using a platinum ring method by using a K100 automatic surface tension meter.

FIG. 5 is a graph showing the relationship between the surface tension and the concentration of the heterocyclic triazinyl-containing quaternary ammonium salt obtained from the measurement results. The CMC values of BTOTB and MTOTB in simulated seawater at 30 ℃ were 0.035mM and 0.11mM, respectively, corresponding to surface tension γ_CMCRespectively is 32.8 mN.m^-1And 35.7mN · m^-1。

Example 4: and (3) measuring the minimum inhibitory concentration of the heterocyclic triazinyl quaternary ammonium salt.

In this example, the minimum inhibitory concentration of the heterocyclic triazinyl-containing quaternary ammonium salt was determined by a standard 2-fold dilution method.

1) Diluting the activated SRB bacterial liquid by using a sterile culture medium to obtain the bacterial quantity of 10⁶Bacteria liquid of the order of magnitude of one/mL.

2) Preparing a certain amount of mother liquor containing heterocyclic triazine-based quaternary ammonium salt by using a sterile culture medium, adding the mother liquor into 10mL test tubes according to a standard 2-fold dilution method to obtain a series of concentration gradients, and adding 1mL of the bacterial liquid into each test tube (the final bacterial liquid is 3-7 multiplied by 10)⁵one/mL).

3) Three parallel tubes were set for each concentration and incubated at 30 ℃ for 14 d.

4) The color change of the medium in the tube was recorded. When SRB grows in the culture medium, black FeS precipitates are generated, and otherwise, the color is not changed. When all three test tubes do not change color, the corresponding concentration is the minimum inhibitory concentration of the bactericide.

The corresponding minimum inhibitory concentrations for the products of examples 1 and 2 are shown in table 1, using dodecyl dimethyl benzyl ammonium chloride (1227) as a reference. It can be seen that BTOTB and MTOTB have significantly better bacteriostatic effects on SRB than 1227.

Example 5: static weightlessness method for testing corrosion inhibition rate of heterocyclic triazine-based quaternary ammonium salt on carbon steel

The carbon steel sheet sample size is 35mm multiplied by 28mm multiplied by 2mm, and 120 mm is used in sequence before testing^#～5000^#Polishing the water phase sand paper to be bright, then degreasing the water phase sand paper by using acetone, dehydrating the water phase sand paper by using absolute ethyl alcohol, and drying the water phase sand paper for later use.

And respectively soaking the processed carbon steel sheet sample in sterile simulated seawater without the corrosion inhibitor and with the corrosion inhibitor adding concentration of 0.1mM, and sealing and hanging the sheet for 21d at 30 ℃.

And (4) taking out the sample after the experiment is finished, removing corrosion products on the surface by using a scrubbing brush, washing by using distilled water, and dehydrating by using absolute ethyl alcohol. The results of the hanging test are shown in FIG. 6.

As is obvious from the figure, the surface of the carbon steel sheet sample added with BTOTB and MTOTB is smooth and bright, and the corrosion inhibition effect on carbon steel is better than 1227.

Example 6: and (3) testing the corrosion inhibition and sterilization performance of the heterocyclic triazine-based quaternary ammonium salt on carbon steel in the presence of SRB by an Electrochemical Impedance Spectroscopy (EIS).

Will 45^#The carbon steel electrode was welded to the copper wire, exposing only one 1.0cm²The square end face of (2) is used as a working face, and the rest part is sealed by epoxy resin.

Using the working face as 120^#～5000^#Polishing the water-phase sand paper to a mirror surface step by step, degreasing the water-phase sand paper by acetone, dehydrating the water-phase sand paper by absolute ethyl alcohol, drying the water-phase sand paper by cold air, and sealing the preservative film for later use. Before electrochemical testing, the treated electrode slice is placed in a super clean bench and is subjected to ultraviolet sterilization for 30 min.

Placing the electrode slice into a sterile simulated seawater anaerobic bottle containing heterocyclic triazinyl quaternary ammonium salt with the concentration of 0.1mM, and respectively adding 2mL of SRB seed liquid (with the bacteria concentration of 10%) into each bottle except for a sterile control⁷one/mL) so that the final solution volume for all bottles is 100 mL.

Introducing 5min N into each anaerobic bottle before sealing₂Sealing, and standing in 30 + -1 deg.C constant temperature incubator for soaking.

After soaking for different days, taking out the electrode slice from the anaerobic bottle, assembling a three-electrode system (a platinum slice electrode is used as an auxiliary electrode, and a saturated calomel electrode is used as a reference electrode) in a super-clean workbench, and carrying out electrochemical EIS test.

FIG. 7(a) is a Nyquist plot of carbon steel after being soaked in SRB simulated seawater without adding corrosion-inhibiting bactericide for different days, and FIGS. 7(b), (c), (d) are Nyquist plots of carbon steel after being soaked in simulated seawater with 0.1mM BTOTB, MTOTB and 1227 respectively for different days. The corrosion inhibition rate results shown in table 2 were finally obtained by fitting with an equivalent circuit.

As can be seen from Table 2, the corrosion inhibition and sterilization performance of the heterocyclic triazine-based quaternary ammonium salt on carbon steel is better than 1227 in all experimental periods.

Example 7: and observing the surface appearance of the carbon steel sheet sample with or without the corrosion inhibitor in the presence of the SRB by using a scanning electron microscope.

The carbon steel sheet sample size is 35mm multiplied by 28mm multiplied by 2mm, and 120 mm is used in sequence before testing^#～5000^#Polishing with water-phase sand paper to brightness, degreasing with acetone, dehydrating with anhydrous ethanol, and drying.

Before the soaking experiment, the processed carbon steel sheet sample is placed in an ultra-clean workbench for ultraviolet sterilization for 30 min.

Respectively filling solutions containing heterocyclic triazine-based quaternary ammonium salt with the concentration of 0.1mM prepared by using sterile simulated seawater into 300mL corrosion inhibition bottles, inoculating activated SRB bacterial liquid into each bottle according to the inoculation amount of 2%, introducing nitrogen to remove oxygen, hanging a carbon steel sheet sample, sealing the corrosion inhibition bottle, and soaking in a constant-temperature water bath at 30 +/-1 ℃ for 21 d.

All the operations are completed in a clean bench.

Taking out the carbon steel sheet sample after the test is finished, removing the corrosion products with loose surface by using a scrubbing brush according to the ASTM G1-03 standard method, then ultrasonically cleaning the sample for 10min at 25 ℃ by using Clark' S solution, then sequentially cleaning the sample by using distilled water and absolute ethyl alcohol, and cleaning the sample in N₂And (4) drying under flowing.

The surface appearance of the carbon steel sheet sample after being soaked in the SRB solution containing or not containing the heterocyclic triazinyl quaternary ammonium salt for 21d is observed by using a scanning electron microscope, and compared with the surface appearance of the carbon steel sheet sample soaked in the SRB solution containing 1227, and the specific result is shown in fig. 8.

FIG. 8(a) is a surface topography of a polished carbon steel sheet sample, showing a smooth and flat surface with clear texture.

FIG. 8(b) shows the corrosion morphology of carbon steel sheet samples after immersion in SRB media without corrosion inhibitor added, a loose porous corrosion product layer was coated on the carbon steel surface, and the presence of sessile SRB strains was easily observed.

Fig. 8(c) is a surface topography of a carbon steel sheet sample after being soaked in the SRB solution added with MTOTB, wherein SRB strains are not found in the surface topography, and an adsorption film on the surface of the carbon steel is complete.

FIG. 8(d) is a surface topography of a carbon steel sheet sample after soaking in the SRB solution with 1227 added, and no SRB strain was found on the surface, but there were more corrosion products.

Thus, the comparison shows that the corrosion inhibition and sterilization performance of the MTOTB on the carbon steel is obviously better than 1227 when the MTOTB exists in the SRB solution.

The above embodiments of the present invention are not intended to be exhaustive or to limit the invention to the precise form disclosed. Various changes, modifications, substitutions and alterations to these embodiments will be apparent to those skilled in the art without departing from the principles and spirit of this invention.