Formamide metal surface corrosion inhibitor material, effect verification method and application

Abstract

The invention provides a formamide metal surface corrosion inhibitor material, an effect verification method and application, and the formamide metal surface corrosion inhibitor material is obtained by carrying out an amidation reaction on a certain amount of 1H-benzimidazole-2-formic acid and a certain amount of 2-amino-5-sulfydryl-1, 3, 4-thiadiazole under a certain condition. The formamide metal surface corrosion inhibitor material provided by the invention is rich in organic functional groups, and can generate adsorption on the metal surface and form a complex, thereby effectively reducing the corrosion effect of materials such as NTO and the like on the metal surface.

Description

Technical Field

[0001] The invention belongs to the technical field of metal corrosion prevention and control, and relates to a method for preparing a formamide-based metal surface corrosion inhibitor. Background Art

[0002] NTO insensitive explosives have attracted much attention for their high energy density and low sensitivity. Their high energy density means that they can release more energy per unit mass or volume, making them more explosive in military and industrial applications. At the same time, their low sensitivity reduces the risk of accidental explosions and enhances handling and storage safety. However, their acidic properties may cause metal corrosion problems, so appropriate anti-corrosion measures must be taken to ensure safety and durability.

[0003] As an effective anti-corrosion tool, organic corrosion inhibitors have broad application prospects in the industrial and military fields. By forming a protective film or adsorbing on the metal surface, organic corrosion inhibitors can effectively slow down the corrosion rate of NTO on metals and extend the service life of metal equipment. However, the research on the reaction between specific organic substances to generate organic corrosion inhibitors in the field has not been perfected, and there is a lack of effective verification methods to prove its specific corrosion inhibition of specific materials (NTO). Summary of the invention

[0004] In view of this, the present invention provides, on the one hand, a method for preparing a formamide-based metal surface corrosion inhibitor, which has a simple process flow, can realize industrialized and standardized production, has easy-to-obtain raw materials, and has stable properties and strong functionality of the product. In addition, the heteroatoms on the customized organic matter obtained by the preparation method of the present invention can be well coordinated with the surface metal atoms, so that the organic molecules are strongly adsorbed on the metal surface to form a covering film, thereby hindering the contact between the metal and the corrosive medium and slowing down the corrosion of the metal.

[0005] In order to achieve the above effect, the present invention provides a formamide-based metal surface corrosion inhibitor material, which is obtained by reacting a certain amount of 1H-benzimidazole-2-carboxylic acid with a certain amount of 2-amino-5-mercapto-1,3,4-thiadiazole through an amidation reaction under certain conditions. The specific structure of the material is as follows:

[0006]

[0007] Optionally, the amidation reaction of a certain amount of 1H-benzimidazole-2-carboxylic acid and a certain amount of 2-amino-5-mercapto-1,3,4-thiadiazole under certain conditions specifically includes: the amount of the 1H-benzimidazole-2-carboxylic acid is 20-25 mmol, and the amount of the 2-amino-5-mercapto-1,3,4-thiadiazole is 20-25 mmol.

[0008] Preferably, the amount of the 1H-benzimidazole-2-carboxylic acid is 21.66 mmol, and the amount of the 2-amino-5-mercapto-1,3,4-thiadiazole is 22.5 mmol.

[0009] Optionally, the amidation reaction of a certain amount of 1H-benzimidazole-2-carboxylic acid with a certain amount of 2-amino-5-mercapto-1,3,4-thiadiazole under certain conditions specifically includes: using O-benzotriazole-N,N,N',N'-tetramethyluronium tetrafluoroborate as a catalyst to promote the formation of amide bonds in the amidation reaction.

[0010] Optionally, the amount of the O-benzotriazole-N,N,N',N'-tetramethyluronium tetrafluoroboric acid is 20-25 mmol.

[0011] Preferably, the amount of the O-benzotriazole-N,N,N',N'-tetramethyluronium tetrafluoroboric acid is 22.5 mmol.

[0012] Optionally, the amidation reaction of a certain amount of 1H-benzimidazole-2-carboxylic acid with a certain amount of 2-amino-5-mercapto-1,3,4-thiadiazole under certain conditions specifically includes:

[0013] The organic strong base used in the amidation reaction is N,N-diisopropylethylamine, and the amount of the N,N-diisopropylethylamine is 40-45 mmol.

[0014] Preferably, the amount of N,N-diisopropylethylamine is 43.32 mmol.

[0015] The second aspect of the present invention provides a method for verifying the effect of a formamide-based metal surface corrosion inhibitor material, which is used to verify the corrosion inhibition effect of the formamide-based metal surface corrosion inhibitor material, and includes the following specific steps: S1: adding the formamide-based metal surface corrosion inhibitor material to a saturated NTO solution; S2: soaking carbon steel in the saturated NTO solution to which the formamide-based metal surface corrosion inhibitor material is added as described in S1, and calculating the corrosion rate of the carbon steel; S3: setting a comparative example, and performing parameter comparison between the corrosion rate calculated in S2 and the comparative example to verify the corrosion inhibition effect of the formamide-based metal surface corrosion inhibitor material.

[0016] Optionally, S3 specifically includes: the comparative example is set to directly immerse carbon steel in a saturated NTO solution without adding the formamide-based metal surface corrosion inhibitor material, and test the corrosion rate.

[0017] A third aspect of the present invention provides an application of a formamide-based metal surface corrosion inhibitor material in the field of metal corrosion prevention and control technology.

[0018] The present invention has at least the following beneficial effects:

[0019] (1) The thiadiazole and thio group in the product N-1,3,4-thiadiazole-2-thio-1H-benzimidazole-2-carboxamide of the present invention can chemically adsorb to the metal surface to form a protective covering layer, thereby preventing NTO molecules from directly contacting the metal surface, thereby slowing down the occurrence of corrosion reactions.

[0020] (2) The functional groups in the product molecules of the present invention can form complexes with metal surface atoms. This complex reaction can reduce the exposure of active sites on the metal surface, reduce the chemical reaction rate between NTO molecules and the metal surface, and thus slow down the occurrence of corrosion.

[0021] (3) The corrosion inhibition verification method of the present invention is simple and effective, and can intuitively reflect the excellent effect of formamide-based organic corrosion inhibition materials on the corrosion protection of NTO materials.

[0022] In addition, additional advantages, objects, and features of the present invention will be described in part in the following description, and will become apparent to those skilled in the art after studying the following, or may be learned from the practice of the present invention. The objects and other advantages of the present invention may be realized and obtained by the structures and method steps specifically pointed out in the written description and claims and the accompanying drawings.

[0023] Those skilled in the art will appreciate that the objectives and advantages that can be achieved with the present invention are not limited to the above specific description, and the above and other objectives that can be achieved by the present invention will be more clearly understood from the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The drawings described herein are used to provide a further understanding of the present invention, constitute a part of this application, and do not constitute a limitation of the present invention.

[0025] Figure 1 is the H NMR spectrum of the N-1,3,4-thiadiazole-2-sulfenyl-1H-benzimidazole-2-carboxamide corrosion inhibitor in Example 3 of the present invention;

[0026] Figure 2 is the infrared spectrum of the N-1,3,4-thiadiazole-2-sulfenyl-1H-benzimidazole-2-carboxamide corrosion inhibitor in Example 3 of the present invention;

[0027] Figure 3 The photoelectron spectrum of the N-1,3,4-thiadiazole-2-sulfenyl-1H-benzimidazole-2-carboxamide corrosion inhibitor in Example 3 of the present invention;

[0028] Figure 4This is the thermogravimetric analysis of the N-1,3,4-thiadiazole-2-sulfenyl-1H-benzimidazole-2-carboxamide corrosion inhibitor in Example 3 of the present invention;

[0029] Figure 5 The molecular structure, frontier orbital and electrostatic potential diagram of the N-1,3,4-thiadiazole-2-sulfenyl-1H-benzimidazole-2-carboxamide corrosion inhibitor in Example 3 of the present invention;

[0030] Figure 6 This is a graph showing the corrosion rate of carbon steel in a saturated NTO solution to which N-1,3,4-thiadiazole-2-sulfenyl-1H-benzimidazole-2-carboxamide corrosion inhibitor is added in Examples 1-4 of the present invention;

[0031] Figure 7 It is a schematic flow chart of a method for verifying the effect of formamide-based metal surface corrosion inhibitor materials according to an embodiment of the present invention. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical scheme and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments and the accompanying drawings. The schematic embodiments of the present invention and their descriptions are used to explain the present invention, but are not intended to limit the present invention. It should also be noted that, in order to avoid blurring the present invention due to unnecessary details, only structures and / or processing steps closely related to the solutions according to the present invention are shown in the accompanying drawings, while other details that are not closely related to the present invention are omitted.

[0033] It should be emphasized that the term “include / comprises” when used herein refers to the presence of features, elements, steps or components, but does not exclude the presence or addition of one or more other features, elements, steps or components.

[0034] The embodiment of the present invention provides a formamide-based metal surface corrosion inhibitor material, which is obtained by reacting a certain amount of 1H-benzimidazole-2-carboxylic acid with a certain amount of 2-amino-5-mercapto-1,3,4-thiadiazole under certain conditions through an amidation reaction. The specific structure of the material is as follows:

[0035]

[0036] Optionally, the amidation reaction of a certain amount of 1H-benzimidazole-2-carboxylic acid and a certain amount of 2-amino-5-mercapto-1,3,4-thiadiazole under certain conditions specifically includes: the amount of 1H-benzimidazole-2-carboxylic acid is 20-25 mmol, and the amount of 2-amino-5-mercapto-1,3,4-thiadiazole is 20-25 mmol.

[0037] Preferably, the amount of 1H-benzimidazole-2-carboxylic acid is 21.66 mmol, and the amount of 2-amino-5-mercapto-1,3,4-thiadiazole is 22.5 mmol.

[0038] Optionally, the amidation reaction of a certain amount of 1H-benzimidazole-2-carboxylic acid and a certain amount of 2-amino-5-mercapto-1,3,4-thiadiazole under certain conditions specifically includes: using O-benzotriazole-N,N,N',N'-tetramethyluronium tetrafluoroborate as a catalyst to promote the formation of amide bonds in the amidation reaction.

[0039] Optionally, the amount of O-benzotriazole-N,N,N',N'-tetramethyluronium tetrafluoroboric acid is 20-25 mmol.

[0040] Preferably, the amount of O-benzotriazole-N,N,N',N'-tetramethyluronium tetrafluoroboric acid is 22.5 mmol.

[0041] Optionally, the amidation reaction of a certain amount of 1H-benzimidazole-2-carboxylic acid and a certain amount of 2-amino-5-mercapto-1,3,4-thiadiazole under certain conditions specifically includes:

[0042] The organic strong base used in the amidation reaction is N,N-diisopropylethylamine, and the amount of N,N-diisopropylethylamine is 40-45 mmol.

[0043] Preferably, the amount of N,N-diisopropylethylamine is 43.32 mmol.

[0044] Combined with Figure 7 According to a second aspect of an embodiment of the present invention, a method for verifying the effect of a formamide-based metal surface corrosion inhibitor material is provided, which is used to verify the corrosion inhibition effect of the formamide-based metal surface corrosion inhibitor material, and includes the following specific steps: S1: adding the formamide-based metal surface corrosion inhibitor material to a saturated NTO solution; S2: soaking carbon steel in the saturated NTO solution in S1 to which the formamide-based metal surface corrosion inhibitor material is added, and calculating the corrosion rate of the carbon steel; S3: setting a comparative example, and performing parameter comparison between the corrosion rate calculated in S2 and the comparative example to verify the corrosion inhibition effect of the formamide-based metal surface corrosion inhibitor material.

[0045] Optionally, S3 specifically includes: a comparative example is set to directly immerse carbon steel in a saturated NTO solution without adding formamide-based metal surface corrosion inhibitor material, and test the corrosion rate.

[0046] A third aspect of an embodiment of the present invention provides an application of a formamide-based metal surface corrosion inhibitor material in the field of metal corrosion prevention and control technology.

[0047] The present invention will be further described in detail below through specific implementation examples. The following examples are only illustrative and not restrictive, and the protection scope of the present invention cannot be limited thereto.

[0048] Example 1

[0049] 20mmol of 1H-benzimidazole-2-carboxylic acid was dissolved in 10mL of ultra-dry tetrahydrofuran, and then 20mmol of O-benzotriazole-N,N,N',N'-tetramethyluronium tetrafluoroboric acid was added to the above solution and stirred at room temperature for 30min. After that, 20mmol of 2-amino-5-mercapto-1,3,4-thiadiazole and 40mmol of N,N-diisopropylethylamine were added and stirred at room temperature for 1h. The reaction was terminated after monitoring by thin layer chromatography, and a saturated sodium chloride solution was added to the mother liquor. The solid formed was filtered and slurried with ethanol, then washed twice with hydrochloric acid and deionized water, and finally adjusted with NaHCO3. The obtained solid was filtered and vacuum dried at 60°C for 12h and then collected to obtain a formamide organic corrosion inhibitor. Finally, the collected formamide organic corrosion inhibitor was added into the NTO saturated solution, and the mass loss of carbon steel immersed in the solution was used to calculate the corrosion rate to verify the effect of the formamide organic corrosion inhibitor.

[0050] Example 2

[0051] 21mmol of 1H-benzimidazole-2-carboxylic acid was dissolved in 15mL of ultra-dry tetrahydrofuran, and then 22mmol of O-benzotriazole-N,N,N',N'-tetramethyluronium tetrafluoroboric acid was added to the above solution and stirred at room temperature for 30min. After that, 21.5mmol of 2-amino-5-mercapto-1,3,4-thiadiazole and 42mmol of N,N-diisopropylethylamine were added and stirred at room temperature for 1.5h. The reaction was terminated after monitoring by thin layer chromatography, and a saturated sodium chloride solution was added to the mother liquor. The solid formed was filtered and slurried with ethanol, then washed twice with hydrochloric acid and deionized water, and finally adjusted with NaHCO3. The obtained solid was filtered and vacuum dried at 60°C for 18h and then collected to obtain a formamide organic corrosion inhibitor. Finally, the collected formamide organic corrosion inhibitor was added into the NTO saturated solution, and the mass loss of carbon steel immersed in the solution was used to calculate the corrosion rate to verify the effect of the formamide organic corrosion inhibitor.

[0052] Example 3

[0053] Combined with Figure 1-5In this embodiment, 21.66mmol of 1H-benzimidazole-2-carboxylic acid was dissolved in 22.5mL of ultra-dry tetrahydrofuran, and then 22.5mmol of O-benzotriazole-N,N,N',N'-tetramethyluronium tetrafluoroboric acid was added to the above solution and stirred at room temperature for 30min. After that, 22.5mmol of 2-amino-5-mercapto-1,3,4-thiadiazole and 43.32mmol of N,N-diisopropylethylamine were added and stirred at room temperature for 2h. The reaction was terminated after monitoring by thin layer chromatography, and a saturated sodium chloride solution was added to the mother liquor. The solid formed was filtered and slurried with ethyl acetate, then washed twice with hydrochloric acid and deionized water, and finally adjusted with NaHCO3. The obtained solid was filtered and vacuum dried at 60°C for 24h and then collected to obtain a formamide organic corrosion inhibitor. Finally, the collected formamide organic corrosion inhibitor was added into the NTO saturated solution, and the mass loss of carbon steel immersed in the solution was used to calculate the corrosion rate to verify the effect of the formamide organic corrosion inhibitor.

[0054] Example 4

[0055] 25mmol of 1H-benzimidazole-2-carboxylic acid was dissolved in 35mL of ultra-dry tetrahydrofuran, and then 25mmol of O-benzotriazole-N,N,N',N'-tetramethyluronium tetrafluoroboric acid was added to the above solution and stirred at room temperature for 30min. After that, 25mmol of 2-amino-5-mercapto-1,3,4-thiadiazole and 45mmol of N,N-diisopropylethylamine were added and stirred at room temperature for 3h. The reaction was terminated after monitoring by thin layer chromatography, and a saturated sodium chloride solution was added to the mother liquor. The solid formed was filtered and slurried with dimethylformamide, then washed with hydrochloric acid and deionized water twice, and finally adjusted with NaHCO3. The obtained solid was filtered and vacuum dried at 60°C for 36h and then collected to obtain a formamide organic corrosion inhibitor. Finally, the collected formamide organic corrosion inhibitor was added into the NTO saturated solution, and the mass loss of carbon steel immersed in the solution was used to calculate the corrosion rate to verify the effect of the formamide organic corrosion inhibitor.

[0056] Comparative Example

[0057] The corrosion rate of carbon steel was tested by directly immersing it in a saturated NTO solution without adding N-1,3,4-thiadiazole-2-thio-1H-benzimidazole-2-carboxamide corrosion inhibitor.

[0058] Table 1. Corrosion inhibition performance of N-1,3,4-thiadiazole-2-thio-1H-benzimidazole-2-carboxamide corrosion inhibitor on NTO

[0059] Group Corrosion rate (mm / y) Comparative Example 9.03 Example 1 6.05 Example 2 5.13 Example 3 4.48 Example 4 4.87

[0060] From the attached Figure 6 It can be seen that the corrosion rate of NTO saturated solution on low carbon steel after adding N-1,3,4-thiadiazole-2-sulfenyl-1H-benzimidazole-2-carboxamide corrosion inhibitor becomes smaller, and its corrosion rate is 4.48mm / y. This is due to the fact that the thiadiazole and thio group in N-1,3,4-thiadiazole-2-sulfenyl-1H-benzimidazole-2-carboxamide can chemically adsorb with the metal surface to form a protective covering layer, preventing NTO molecules from directly contacting the metal surface, thereby slowing down the occurrence of corrosion reactions. In addition, the functional groups in the molecules can form complexes with metal surface atoms. This complex reaction can reduce the exposure of active sites on the metal surface, reduce the chemical reaction rate between NTO molecules and the metal surface, and thus slow down the occurrence of corrosion.

[0061] In addition, the N-1,3,4-thiadiazole-2-sulfenyl-1H-benzimidazole-2-carboxamide corrosion inhibitor prepared by the present invention does not reduce the energy level of NTO and can inhibit its corrosion, and the preparation method is simple, easy to operate, and has low production cost, which meets the requirements for long-term storage of NTO-based weapons and equipment.

[0062] The specific description above further illustrates the purpose, technical solutions and beneficial effects of the invention in detail. It should be understood that the above is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A formamide-based metal surface corrosion inhibitor material, obtained by reacting a certain amount of 1H-benzimidazole-2-carboxylic acid with a certain amount of 2-amino-5-mercapto-1,3,4-thiadiazole under certain conditions. It is characterized in that The specific structure of the material is as follows:

2. The formamide-based metal surface corrosion inhibitor material according to claim 1, It is characterized in that The method of reacting a certain amount of 1H-benzimidazole-2-carboxylic acid with a certain amount of 2-amino-5-mercapto-1,3,4-thiadiazole through an amidation reaction under certain conditions specifically includes: The amount of the 1H-benzimidazole-2-carboxylic acid is 20-25 mmol, and the amount of the 2-amino-5-mercapto-1,3,4-thiadiazole is 20-25 mmol.

3. The formamide-based metal surface corrosion inhibitor material according to claim 2, Features: Preferably, the amount of the 1H-benzimidazole-2-carboxylic acid is 21.66 mmol, and the amount of the 2-amino-5-mercapto-1,3,4-thiadiazole is 22.5 mmol.

4. The formamide-based metal surface corrosion inhibitor material according to claim 1, It is characterized in that The method of reacting a certain amount of 1H-benzimidazole-2-carboxylic acid with a certain amount of 2-amino-5-mercapto-1,3,4-thiadiazole through an amidation reaction under certain conditions specifically includes: In the amidation reaction, O-benzotriazole-N,N,N',N'-tetramethyluronium tetrafluoroboric acid is used as a catalyst to promote the formation of amide bonds.

5. The formamide-based metal surface corrosion inhibitor material according to claim 4, Features: The amount of the O-benzotriazole-N,N,N',N'-tetramethyluronium tetrafluoroboric acid is 20-25 mmol.

6. The formamide-based metal surface corrosion inhibitor material according to claim 5, Features: Preferably, the amount of the O-benzotriazole-N,N,N',N'-tetramethyluronium tetrafluoroboric acid is 22.5 mmol.

7. The formamide-based metal surface corrosion inhibitor material according to claim 1, It is characterized in that The method of reacting a certain amount of 1H-benzimidazole-2-carboxylic acid with a certain amount of 2-amino-5-mercapto-1,3,4-thiadiazole through an amidation reaction under certain conditions specifically includes: The organic strong base used in the amidation reaction is N,N-diisopropylethylamine, and the amount of the N,N-diisopropylethylamine is 40-45 mmol.

8. The formamide-based metal surface corrosion inhibitor material according to claim 7, Features: Preferably, the amount of N,N-diisopropylethylamine is 43.32 mmol.

9. A method for verifying the effect of a formamide-based metal surface corrosion inhibitor material, for verifying the corrosion inhibition effect of the formamide-based metal surface corrosion inhibitor material according to any one of claims 1 to 8, It is characterized in that The specific steps include: S1: adding the formamide-based metal surface corrosion inhibitor material into a saturated NTO solution; S2: taking carbon steel and immersing it in the NTO saturated solution to which the formamide-based metal surface corrosion inhibitor material is added as described in S1, and calculating the corrosion rate of the carbon steel; S3: Setting a comparative example, and performing parameter comparison between the corrosion rate calculated in S2 and the comparative example, so as to verify the corrosion inhibition effect of the formamide-based metal surface corrosion inhibitor material.

10. The method for verifying the effect of the formamide-based metal surface corrosion inhibitor material according to claim 9, It is characterized in that The S3 specifically includes: The comparative example is set to directly immerse carbon steel in a saturated NTO solution without adding the formamide-based metal surface corrosion inhibitor material, and test the corrosion rate.

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