A triazine ring-containing cationic Gemini surfactant and its application

Abstract

The present invention discloses a triazine ring-containing cationic Gemini surfactant having a structure represented by the following general formula (I): #imgabs0#, wherein m = 6 to 16, and n = 2 to 6. Leveraging the molecular structural characteristics of the triazine ring-containing surfactant and the effects of its quaternary ammonium salt functional groups, the present invention achieves high corrosion inhibition and sterilization efficiencies even at relatively low dosages. The surfactant can be used as a corrosion inhibitor, particularly for corrosion inhibition and sterilization of carbon steel in the presence of sulfate-reducing bacteria.

Description

Technical Field

[0001] The present invention belongs to the technical field of metal corrosion and protection, and relates to a Gemini surfactant with a sustained-release effect, in particular to a triazine ring-based cationic Gemini surfactant. Background Art

[0002] Carbon steel, with its relatively low cost and excellent processability, is widely used in coastal infrastructure and marine engineering facilities, including cross-sea bridges, ports, and submarine pipelines. However, in practice, carbon steel is susceptible to chemical corrosion, electrochemical corrosion, and microbial corrosion caused by microorganisms, resulting in significant economic losses and serious safety and environmental issues.

[0003] Sulfate-reducing bacteria (SRB) are the main bacteria that cause microbial corrosion. They use organic matter in the solution or organisms adsorbed on the metal surface as carbon sources to convert SO4 2- Restore to S 2- SRBs utilize microorganisms to generate the energy they need for growth and reproduction. The metabolite, H2S, causes corrosion of carbon steel, generating the corrosion product FeS. Furthermore, SRBs and their metabolites adhering to the metal surface alter the local environment, promoting self-accelerated corrosion. Therefore, to ensure the proper functioning of metals in the presence of microorganisms, protection against microbial corrosion is essential.

[0004] Adding corrosion inhibitors and biocides is currently the simplest and most effective way to inhibit microbial corrosion of metals. However, after long-term use, SRB gradually develop resistance to traditional biocides, resulting in shortcomings such as short duration of efficacy and high dosage requirements. Therefore, the development of a new, highly effective corrosion inhibitor and biocide is of great practical significance for inhibiting SRB corrosion.

[0005] Cationic Gemini surfactant molecules containing triazine rings have unique amphiphilic properties and can form a hydrophobic barrier on the metal surface, preventing the metal from contacting the corrosive medium, thereby enhancing the corrosion inhibition effect on carbon steel; secondly, the molecular structure is rich in heteroatom N and shared π electrons, which can form coordination bonds with the empty d orbitals of iron for chemical adsorption, further preventing corrosion reactions from occurring; furthermore, the active part on the triazine ring can also form hydrogen bonds with the bases in sulfate-reducing bacteria (SRB), adsorb on the bacterial cells and destroy the bacterial structure, thereby enhancing the corrosion inhibition and bactericidal effect. Summary of the Invention

[0006] The present invention aims to provide a triazine ring-containing cationic Gemini surfactant, which can achieve high corrosion inhibition and sterilization efficiency at a relatively low dosage through the synergistic effect of the molecular structure characteristics of the triazine ring-containing surfactant and the quaternary ammonium salt functional group.

[0007] The triazine ring-containing cationic Gemini surfactant of the present invention has a structure represented by the general formula (I):

[0008]

[0009] Among them, m=12~16, n=2~6.

[0010] Further preferably, both m and n are even numbers.

[0011] Furthermore, m is 12-16, more preferably 12 or 14.

[0012] Furthermore, n is 2 or 6, more preferably 2.

[0013] The present invention provides the use of the triazine ring-containing cationic Gemini surfactant as a corrosion inhibitor.

[0014] Specifically, the present invention provides the use of the triazine ring-containing cationic Gemini surfactant as a corrosion inhibitor for inhibiting sulfate-reducing bacteria corrosion.

[0015] Furthermore, the present invention also provides the use of the triazine ring-containing cationic Gemini surfactant as a bactericide against sulfate-reducing bacteria.

[0016] More specifically, the present invention provides the use of the triazine ring-containing cationic Gemini surfactant as a corrosion inhibitor and bactericide for carbon steel in the presence of sulfate-reducing bacteria.

[0017] The triazine ring-containing cationic Gemini surfactant of the present invention comprises an alkane chain, a triazine ring and a quaternary ammonium salt structure in its molecular structure. The abundant heteroatom N and shared π electrons in the molecular structure can form coordination bonds with the empty d orbitals of iron for chemical adsorption. When coated on the surface of carbon steel, the surfactant can block contact between the metal and the corrosive medium, thereby enhancing its corrosion inhibition effect on the carbon steel.

[0018] At the same time, the quaternary ammonium salts in the molecular structure can adsorb on the surface of SRB biofilms and penetrate into the cell membrane, thereby altering the cell membrane's biological functions such as electron transfer, selective mass transfer, and isolation barriers, disrupting the cell membrane's selective permeability and genetic system, leading to the inhibition of SRB activity and even death. Furthermore, cationic Gemini surfactants containing triazine rings compete with SRB for adsorption on carbon steel surfaces, preferentially adsorbing on the carbon steel surface, hindering SRB adsorption on the carbon steel surface and the resulting microbial corrosion of carbon steel.

[0019] Therefore, the triazine ring-containing cationic Gemini surfactant based on the above structure of the present invention can have higher corrosion inhibition and sterilization performance at a relatively low usage amount. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is the infrared spectrum of the triazine ring-containing cationic Gemini surfactant C12-6-C12 in Example 1.

[0021] Figure 2 The triazine ring cationic Gemini surfactant C12-6-C12 of Example 1 is 1 H NMR spectrum.

[0022] Figure 3 This is the infrared spectrum of the triazine ring-containing cationic Gemini surfactant C12-2-C12 in Example 2.

[0023] Figure 4 The cationic Gemini surfactant C12-2-C12 containing triazine ring in Example 2 is 1 H NMR spectrum.

[0024] Figure 5 This is the infrared spectrum of the triazine ring-containing cationic Gemini surfactant C14-2-C14 in Example 3.

[0025] Figure 6 The triazine ring cationic Gemini surfactant C14-2-C14 of Example 3 is 1 H NMR spectrum.

[0026] Figure 7 It is a static weight loss diagram.

[0027] Figure 8 Nyquist plots of carbon steel immersed in simulated seawater containing SRB for different days without or with 0.2 mM of different triazine ring-containing cationic Gemini surfactants. In the figure: (a) SRB, (b) 1227, (c) C12-6-C12, (d) C12-2-C12, and (e) C14-2-C14. Implementation Method

[0028] The following embodiments are only used to more clearly illustrate the technical solutions of the present invention so that those skilled in the art can better understand and utilize the present invention, but are not intended to limit the scope of protection of the present invention.

[0029] Unless otherwise specified, the production processes, experimental methods or detection methods involved in the embodiments of the present invention are all conventional methods in the prior art, and their names and / or abbreviations are conventional names in the field and are very clear and unambiguous in the relevant fields of use. Those skilled in the art can understand the conventional process steps based on the names and apply the corresponding equipment to implement them according to conventional conditions or the conditions recommended by the manufacturer.

[0030] The various instruments, equipment, raw materials or reagents used in the embodiments of the present invention are not particularly limited in their sources and are all conventional products that can be purchased through regular commercial channels or prepared according to conventional methods well known to those skilled in the art. Example

[0031] Example 1

[0032] Add 0.1 mol of cyanuric chloride and 100 mL of toluene to a 500 mL three-necked flask and stir at -5-0°C until completely dissolved. Dissolve 0.12 mol of dodecylamine in toluene and add it dropwise to the flask at a rate of 3-4 drops / s. Monitor the reaction until completion and perform post-processing to obtain a monosubstituted product.

[0033] Add 0.1 mol of the monosubstituted product and 50 mL of acetone to a 500 mL four-necked flask and stir at 30-35°C until dissolved. Dissolve 0.1 mol of hexamethylenediamine in acetone and add it dropwise to the flask at a rate of 3-4 drops / s. Adjust the pH of the reaction system to 8-9. Monitor the reaction until completion and perform post-treatment to obtain the disubstituted product.

[0034] Add 0.66 mol of N,N-dimethyl-1,3-propylenediamine to a 100 mL three-necked flask, control the reaction temperature at 100-105°C, add 0.1 mol of the disubstituted product to the three-necked flask in small amounts several times, monitor the reaction until completion, and perform post-treatment to obtain the trisubstituted product.

[0035] 0.1 mol of the trisubstituted product and 50 mL of acetone were added to a 100 mL three-necked flask, and the mixture was stirred at 50-55°C until fully dissolved. 0.25 mol of ethyl bromide was then added, and the reaction was monitored until completion. After post-treatment, a triazine ring-containing cationic Gemini surfactant represented by the general formula (II) was obtained, which was designated as C12-6-C12.

[0036]

[0037] according to Figure 1 Infrared spectra and Figure 2 of 1The structure of the target product was characterized by H NMR spectrum, which proved that the cationic Gemini surfactant containing triazine ring with the structure described in this example was finally prepared. Furthermore, in the ESI-MS spectrum of the target product, 449.42 m / z was C12-6-C12 [M-2Br - ] 2+ / 2 peak, 979.76m / z is C12-6-C12 [M-Br - ] + peak.

[0038] Example 2

[0039] Add 0.1 mol of cyanuric chloride and 100 mL of toluene to a 500 mL three-necked flask and stir at -5-0°C until completely dissolved. Dissolve 0.12 mol of dodecylamine in toluene and add it dropwise to the flask at a rate of 3-4 drops / s. Monitor the reaction until completion and perform post-processing to obtain a monosubstituted product.

[0040] Add 0.1 mol of the monosubstituted product and 50 mL of acetone to a 500 mL four-necked flask and stir at 30-35°C until dissolved. Dissolve 0.1 mol of ethylenediamine in acetone and add it dropwise to the flask at a rate of 3-4 drops / s. Adjust the pH of the reaction system to 8-9. Monitor the reaction until completion and perform post-treatment to obtain the disubstituted product.

[0041] Add 0.66 mol of N,N-dimethyl-1,3-propylenediamine to a 100 mL three-necked flask, control the reaction temperature at 100-105°C, add 0.1 mol of the disubstituted product to the three-necked flask in small amounts several times, monitor the reaction until completion, and perform post-treatment to obtain the trisubstituted product.

[0042] 0.1 mol of the trisubstituted product and 50 mL of acetone were added to a 100 mL three-necked flask, and the mixture was stirred at 50-55°C until fully dissolved. 0.25 mol of ethyl bromide was then added, and the reaction was monitored until completion. After post-treatment, a triazine ring-containing cationic Gemini surfactant represented by the general formula (III) was obtained, which was designated as C12-2-C12.

[0043] according to Figure 3 Infrared spectra and Figure 4 of 1 The target product was characterized by H NMR spectrum, which proved that the cationic Gemini surfactant containing triazine rings with the structure described in this example was finally prepared. Furthermore, in the ESI-MS spectrum of the target product, 421.39 m / z was C12-2-C12 [M-2Br - ] 2+ / 2 peak, 923.69m / z is C12-2-C12 [M-Br - ]+ peak.

[0044]

[0045] Example 3

[0046] Add 0.1 mol of cyanuric chloride and 100 mL of toluene to a 500 mL three-necked flask and stir at -5-0°C until completely dissolved. Dissolve 0.12 mol of tetradecylamine in toluene and add dropwise to the flask at a rate of 3-4 drops / s. Monitor the reaction until completion and perform post-processing to obtain a monosubstituted product.

[0047] Add 0.1 mol of the monosubstituted product and 50 mL of acetone to a 500 mL four-necked flask and stir at 30-35°C until dissolved. Dissolve 0.1 mol of ethylenediamine in acetone and add it dropwise to the flask at a rate of 3-4 drops / s. Adjust the pH of the reaction system to 8-9. Monitor the reaction until completion and perform post-treatment to obtain the disubstituted product.

[0048] Add 0.66 mol of N,N-dimethyl-1,3-propylenediamine to a 100 mL three-necked flask, control the reaction temperature at 100-105°C, add 0.1 mol of the disubstituted product to the three-necked flask in small amounts several times, monitor the reaction until completion, and perform post-treatment to obtain the trisubstituted product.

[0049] 0.1 mol of the trisubstituted product and 50 mL of acetone were added to a 100 mL three-necked flask, and the mixture was stirred at 50-55°C until fully dissolved. 0.25 mol of ethyl bromide was then added, and the reaction was monitored until completion. After post-treatment, a triazine ring-containing cationic Gemini surfactant represented by the general formula (IV) was obtained, which was designated as C14-2-C14.

[0050] according to Figure 5 Infrared spectra and Figure 6 of 1 The target product was characterized by H NMR spectrum, which proved that the cationic Gemini surfactant containing triazine rings with the structure described in this example was finally prepared. Furthermore, in the ESI-MS spectrum of the target product, 449.42 m / z was C14-2-C14 [M-2Br - ] 2+ / 2 peak, 979.76m / z is C14-2-C14 [M-Br - ] + peak.

[0051]

[0052] Using the traditional bactericide dodecyldimethylbenzyl ammonium chloride (1227) as a control, the corrosion inhibition and bactericidal performance of the triazine ring-containing cationic Gemini surfactants prepared in the above Examples 1 to 3 was tested in bacteria-containing simulated seawater.

[0053] Example 4: Minimum Inhibitory Concentration Determination

[0054] This test example uses the standard two-fold dilution method to determine the minimum inhibitory concentration of 1227 and three triazine ring-containing cationic Gemini surfactants.

[0055] 1227 and the triazine ring-containing cationic Gemini surfactants of Examples 1 to 3 were diluted with culture medium to form a series of concentration gradient solutions, which were added to test tubes respectively, with three parallel test tubes set up for each concentration.

[0056] Add 2% SRB solution to each tube, shake thoroughly, and incubate in a 30°C biochemical incubator for 14 days. Record the color change of the culture medium in the test tube.

[0057] When SRB grows in the culture medium, it produces a black FeS precipitate. Otherwise, it does not change color. When all three test tubes do not change color, the corresponding concentration is the minimum inhibitory concentration of the surfactant.

[0058] The results showed that the minimum inhibitory concentrations of 1227, C12-6-C12, C12-2-C12 and C14-2-C14 were 0.3mM, 0.05mM, 0.021mM and 0.005mM, respectively. The inhibitory concentrations of triazine ring-containing cationic Gemini surfactants against SRB were significantly lower than those of 1227.

[0059] Example 5: Determination of corrosion inhibition rate of carbon steel

[0060] The static weight loss method was used to test the corrosion inhibition rate of 1227 and the triazine ring-containing cationic Gemini surfactants of Examples 1 to 3 on carbon steel in a simulated seawater solution in the presence of SRB.

[0061] The carbon steel sheet specimens were 35 mm × 28 mm × 2 mm in size. Before testing, they were polished to a bright finish using 120# to 3000# aqueous sandpaper, then degreased with acetone and dehydrated with anhydrous ethanol. The specimens were weighed and their mass before weight loss was recorded. They were then sterilized under ultraviolet light for 30 min.

[0062] The treated carbon steel sheet samples were immersed in bacteria-containing simulated seawater solutions without corrosion inhibitors or with different surfactant concentrations, and then sealed at 30°C for 21 days.

[0063] After the experiment, the sample was removed and the biofilm and corrosion products were eliminated using a solution consisting of 100 mL of hydrochloric acid (density 1.19 g / mL), 900 mL of deionized water, and 5 g of hexamethylenetetramine. The sample was then rinsed with distilled water, cleaned with anhydrous ethanol, and dried under a nitrogen atmosphere. The weight after 21 days of corrosion was recorded.

[0064] The static weight loss related data are shown in Table 1. R is the corrosion rate; η W Is the corrosion inhibition rate. The static weight loss corrosion rate and corrosion inhibition rate are shown in the figure Figure 7 shown.

[0065] From the data in Table 1 and Figure 7 It can be seen that as the concentration increases, the corrosion rates of 1227 and the triazine ring-containing cationic Gemini surfactants from Examples 1 to 3 decrease, and the corrosion inhibition rates increase. Furthermore, the corrosion inhibition rates of C12-6-C12, C12-2-C12, and C14-2-C14 are all higher than those of 1227.

[0066]

[0067] Example 6: Carbon Steel Corrosion Inhibition Performance Test

[0068] Electrochemical impedance spectroscopy (EIS) was used to test the corrosion inhibition performance of 1227 and triazine ring-containing cationic Gemini surfactants of Examples 1 to 3 on carbon steel in the presence of SRB.

[0069] The working electrode was prepared using Q235 carbon steel and welded to a copper wire, with only a 1 cm 2 The square is used as the working surface, and the rest is sealed with epoxy resin. The working electrode is polished to a mirror surface with 120# to 3000# sandpaper, then cleaned with distilled water, acetone, and anhydrous ethanol in sequence, dried, and sealed for later use.

[0070] Before the electrochemical test, the treated electrode sheets were placed in a clean bench and irradiated under ultraviolet light for at least 30 minutes to ensure that they would not be contaminated by other bacteria.

[0071] The electrode sheets were placed in anaerobic bottles containing 1227 at a concentration of 0.2 mM and the triazine ring cationic Gemini surfactants of Examples 1 to 3. Except for the blank control group, 2% bacterial solution was added to each anaerobic bottle. Before sealing each anaerobic bottle, N2 was passed through it for 5 minutes to exclude O2. The bottle was placed in an incubator and immersed in a static state at 30 (± 1) ° C. After soaking for different days (1 day, 3 days, 5 days, 10 days, 15 days and 21 days), the electrode sheets were removed from the anaerobic bottles, and a three-electrode system (the counter electrode and the reference electrode were a platinum electrode and a saturated calomel electrode, respectively) was assembled in a clean bench for electrochemical impedance spectroscopy (EIS) testing.

[0072] Figure 8 These are the Nyquist plots of carbon steel fitted using an equivalent circuit after immersion for different days in a simulated seawater solution containing bacteria without adding corrosion inhibitors and biocides or with a corrosion inhibitor and biocide concentration of 0.2 mM. (a), (b), (c), (d), and (e) show the EIS curves of SRB and the addition of 1227, C12-6-C12, C12-2-C12, and C14-2-C14 to the SRB-containing culture medium solution, respectively.

[0073] As can be seen from Table 2, in all experimental cycles, the corrosion inhibition and bactericidal performance of the three triazine ring-containing cationic Gemini surfactants on carbon steel were better than those of 1227, indicating that the dual R4N + The base can effectively slow down the corrosion of SRB to carbon steel, which is mainly due to the fact that R4N + The base can change the permeability of cells, causing cell death and playing a bactericidal role.

[0074]

[0075] The above embodiments of the present invention do not describe all details in detail, nor do they limit the present invention to the above embodiments. Various changes, modifications, substitutions, and variations made by those skilled in the art without departing from the principles and purpose of the present invention are intended to be included within the scope of protection of the present invention.

Claims

1. A triazine ring-containing cationic Gemini surfactant capable of inhibiting the corrosion of sulfate-reducing bacteria in carbon steel, having a structure represented by general formula (I): ， in, m=6~16, n=2~6, and both m and n are even numbers.

2. The triazine ring-containing cationic Gemini surfactant according to claim 1, wherein m is an even number of 12 to 16.

3. The triazine ring-containing cationic Gemini surfactant according to claim 2, wherein m is 12 or 14.

4. The triazine ring-containing cationic Gemini surfactant according to claim 1, wherein n is 2 or 6. The triazine ring-containing cationic Gemini surfactant according to claim 4 , wherein n is 2.

6. Use of the triazine ring-containing cationic Gemini surfactant according to claim 1 as a corrosion inhibitor.

7. Use of the triazine ring-containing cationic Gemini surfactant according to claim 1 as a corrosion inhibitor for inhibiting sulfate-reducing bacteria corrosion.

8. Use of the triazine ring-containing cationic Gemini surfactant according to claim 1 as a bactericide against sulfate-reducing bacteria.

9. Use of the triazine ring-containing cationic Gemini surfactant according to claim 1 as a corrosion inhibitor and bactericide for carbon steel in the presence of sulfate-reducing bacteria.

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