Molecular sieve packaged with corrosion inhibitor and preparation method thereof

Abstract

The invention belongs to the field of materials, and particularly relates to a molecular sieve packaged with a corrosion inhibitor and a preparation method of the molecular sieve. A molecular sieve encapsulated with a corrosion inhibitor comprises: a molecular sieve; the corrosion inhibitor is packaged in the molecular sieve; wherein the specific surface area of the molecular sieve is 1-20 m < 2 > / g, the average pore volume is 0.5-1.5 cm < 3 > / g, and the average pore size is 5-15 nm. By controlling the specific surface area, the pore volume, the pore diameter and other parameters of the molecular sieve in the range, the corrosion inhibition compound can be controllably released, so that the loss of the corrosion inhibition compound in the corrosion-resistant coating is reduced, and the corrosion resistance of the coating is enhanced.

Description

Technical Field

[0001] This invention belongs to the field of materials, specifically relating to a molecular sieve encapsulated with a corrosion inhibitor and its preparation method. Background Technology

[0002] Coatings are often needed to protect easily corroded metal surfaces such as steel and copper sheets, giving them corrosion resistance. However, the corrosion inhibitors in existing corrosion-resistant coatings are easily lost, resulting in the coating's lifespan not meeting requirements.

[0003] Therefore, there is a need in the art for a material in which the corrosion-inhibiting compounds are not easily lost, thereby increasing the service life of corrosion-resistant coatings. Summary of the Invention

[0004] The applicant has creatively discovered that by controlling the specific surface area, pore volume, pore size, and other parameters of molecular sieves within a certain range, the corrosion-inhibiting compounds can be released in a controlled manner, thereby reducing their loss in the corrosion-resistant coating and enhancing the corrosion resistance of the coating.

[0005] In view of this, in a first aspect, the present invention provides a molecular sieve encapsulated with a corrosion inhibitor, comprising:

[0006] Molecular sieves;

[0007] Corrosion inhibitor, wherein the corrosion inhibitor is encapsulated inside the molecular sieve;

[0008] in,

[0009] The specific surface area of ​​the molecular sieve is 1–20 m². 2 / g, average pore volume is 0.5~1.5cm³ 3 / g, and an average pore size of 5–15 nm.

[0010] By controlling the specific surface area, pore volume, pore size and other parameters of the molecular sieve within the specified range, the corrosion inhibitor compound can be released in a controlled manner, thereby reducing its loss in the corrosion-resistant coating and enhancing the corrosion resistance of the coating.

[0011] Furthermore, the specific surface area is preferably 4.0–11.2 m². 2 / g:

[0012] Furthermore, the average pore volume is 0.8–1.2 cm³. 3 / g, and further, the average pore volume is 1.1cm³. 3 / g.

[0013] Furthermore, the average pore size is 8–12 nm, and even further, the average pore size is 10 nm.

[0014] Using molecular sieves with the above parameters results in better corrosion resistance in the coating.

[0015] Furthermore, the molecular sieve also includes an encapsulating compound.

[0016] Furthermore, the molecular sieve is a silicon-based molecular sieve. Specifically, examples include SBA-15, MCM-41, MCM-48, KIT-6, SBA-16, FSM-16, and HMS.

[0017] Furthermore, the corrosion inhibitor may be selected from one or more of the following corrosion inhibitors:

[0018] 2-Mercaptobenzothiazole, benzotriazole, tolyltriazole, 5-methylbenzotriazole, 2-mercaptobenzoimidazol, 8-hydroxyquinoline, 2-mercaptobenzoxazole, 1-hydroxybenzotriazole, 2-aminopyrimidine, 2-mercapto-1,3,4-thiadiazole, or mercaptoacetic acid.

[0019] Furthermore, the encapsulating compound may be selected from one or more of the following encapsulating compounds:

[0020] Tetramercaptopentaerythritol ester, bis(3-mercaptopropyl)dimethoxysilane, mercaptopropylsilsesquioxane, tetramercaptopropylsilane, or tris(3-mercaptopropyl)trimethoxysilane.

[0021] Secondly, the present invention provides a method for preparing a molecular sieve encapsulated with a corrosion inhibitor, comprising the following steps:

[0022] S1. Preparation of molecular sieves modified with vinyl sites;

[0023] S2, The molecular sieve obtained in step S1 and the corrosion inhibitor are subjected to electron beam irradiation together; and

[0024] S3. The molecular sieve obtained in step S2 is filtered, washed and dried to finally prepare a molecular sieve encapsulated with a corrosion inhibitor.

[0025] Further, step S1 specifically includes: mixing and reacting the molecular sieve with vinylsilane.

[0026] Furthermore, the molecular sieve is a silicon-based molecular sieve. Specifically, examples include SBA-15, MCM-41, MCM-48, KIT-6, SBA-16, FSM-16, and HMS.

[0027] Furthermore, in step S2, the dose range of the electron beam is 1–500 kGy, preferably 1–200 kGy, and more preferably 60–150 kGy.

[0028] In one specific implementation, the intensity of the electron beam is 10 MeV.

[0029] Furthermore, the mass ratio of the corrosion inhibitor to the molecular sieve is preferably 5–15 mmol / g, 6–12 mmol / g, and more preferably 10 mmol / g.

[0030] Furthermore, the corrosion inhibitor may be selected from one or more of the following corrosion inhibitors:

[0031] 2-Mercaptobenzothiazole, benzotriazole, tolyltriazole, 5-methylbenzotriazole, 2-mercaptobenzoimidazol, 8-hydroxyquinoline, 2-mercaptobenzoxazole, 1-hydroxybenzotriazole, 2-aminopyrimidine, 2-mercapto-1,3,4-thiadiazole, or mercaptoacetic acid.

[0032] Furthermore, step S2 also includes the encapsulation compound being irradiated by an electron beam along with the molecular sieve and corrosion inhibitor.

[0033] Furthermore, the encapsulating compound may be selected from one or more of the following encapsulating compounds:

[0034] Tetramercaptopentaerythritol ester, bis(3-mercaptopropyl)dimethoxysilane, mercaptopropylsilsesquioxane, tetramercaptopropylsilane, or tris(3-mercaptopropyl)trimethoxysilane.

[0035] Furthermore, the mass ratio of the encapsulated compound to the molecular sieve is preferably 0.5–1.5 mmol / g, more preferably 0.6–1.2 mmol / g, and even more preferably 1.0 mmol / g.

[0036] Furthermore, the washing condition in step S3 is to wash three times with ethanol.

[0037] Furthermore, the drying conditions in step S3 are vacuum drying in an oven at 80°C overnight.

[0038] Thirdly, the present invention provides a molecular sieve encapsulated with a corrosion inhibitor, including a molecular sieve prepared according to the preparation method described above.

[0039] Fourthly, the present invention provides a coating comprising the molecular sieve described above. Attached Figure Description

[0040] Figure 1 This is a schematic diagram of the preparation method of the present invention;

[0041] Figures 2-4 The diagrams show the specific surface area, pore volume distribution, and pore size distribution of the molecular sieves prepared according to the embodiments of the present invention.

[0042] Figure 5 Fourier transform infrared spectrum;

[0043] Figure 6 X-ray powder diffraction pattern;

[0044] Figure 7 This is a graph showing the results of elemental analysis. Detailed Implementation

[0045] The present invention will be described in detail below with reference to specific implementation schemes and embodiments, thereby making the advantages and various effects of the present invention more clearly apparent. Those skilled in the art should understand that these specific implementation schemes and embodiments are for illustrative purposes only and are not intended to limit the present invention.

[0046] The "range" disclosed in this application is defined by a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, which define the boundaries of a particular range. Ranges defined in this way can include or exclude endpoints and can be arbitrarily combined; that is, any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60-120 and 80-110 are listed for a specific parameter, it is expected that ranges of 60-110 and 80-120 are also included. Furthermore, if minimum range values ​​of 1 and 2 are listed, and if maximum range values ​​of 3, 4, and 5 are listed, then the following ranges are all expected: 1-3, 1-4, 1-5, 2-3, 2-4, and 2-5. In this application, unless otherwise stated, the numerical range "ab" represents a shortened representation of any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "0-5" indicates that all real numbers between "0-5" have been listed in this article; "0-5" is simply a shortened representation of these numerical combinations. Furthermore, when a parameter is stated as an integer ≥2, it is equivalent to disclosing that the parameter is, for example, an integer such as 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0047] Unless otherwise specified, all embodiments and optional embodiments of this application may be combined to form new technical solutions.

[0048] Unless otherwise specified, all technical features and optional technical features of this application may be combined to form new technical solutions.

[0049] Unless otherwise specified, all steps in this application may be performed sequentially or randomly, preferably sequentially. For example, the method includes steps (a) and (b), indicating that the method may include steps (a) and (b) performed sequentially, or it may include steps (b) and (a) performed sequentially. For example, the mention that the method may also include step (c) indicates that step (c) may be added to the method in any order. For example, the method may include steps (a), (b), and (c), or it may include steps (a), (c), and (b), or it may include steps (c), (a), and (b), etc.

[0050] Unless otherwise specified, the terms used in this application have the common meanings as commonly understood by those skilled in the art.

[0051] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit this disclosure. When used herein, the singular forms “a,” “an,” and “the” are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “comprise” and / or “comprising,” when used in this specification, identify the presence of the stated features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups. When used herein, the term “and / or” includes any and all combinations of the associated listed items.

[0052] Example 1: Preparation of the molecular sieve encapsulated with corrosion inhibitor according to the present invention

[0053] Exemplary preparation methods such as Figure 1 As shown.

[0054] The first step is to modify vinyl sites on commercially available, large-scale-producible SBA-15 molecular sieves. Vinyl silanes are blended at room temperature and reacted for 2 hours. Excess vinyl silanes are washed away and dried to obtain SBA-15-V solid particles modified with vinyl sites.

[0055] The second step is electron beam encapsulation. A certain mass of SBA-15 solid, corrosion inhibitor, and encapsulation compound (the corrosion inhibitors are 2-mercaptobenzothiazole and benzotriazole, and the encapsulation compound is tetramercaptopentaerythritol ester) are added to a glass bottle in a specific ratio (because the molecular weights of the corrosion inhibitor molecules are different, the molar ratio is 10 mmol corrosion inhibitor to 1 g molecular sieve, and the ratio of the encapsulation compound is 1 mmol encapsulation compound to 1 g molecular sieve). A small amount of ethanol solvent is added, the glass bottle is capped, and shaken to mix. The glass bottle is then placed under a 10 MeV electron beam and exposed to a certain dose of electron beam radiation (80 kGy) before being removed.

[0056] The third step is post-treatment after washing and drying. The solid nanoparticles SIB (Ship in Bottle) corrosion inhibitor, which have been grafted and encapsulated by electron beam radiation, are filtered, washed with ethanol (20 mL × 3), and placed in an 80°C oven for vacuum drying overnight. This completes all the steps.

[0057] Examples 2-4

[0058] The preparation method is basically the same as that in Example 1, the only difference being the radiation doses of 96kGy, 112kGy, and 128kGy, respectively.

[0059] Examples 5-6

[0060] The preparation method is basically the same as that in Example 1, the only difference being that the molecular sieves are MCM-41 and KIT-6, respectively.

[0061] Examples 7-9

[0062] The preparation method is basically the same as that in Example 1, the only difference being that the corrosion inhibitors are 2-mercaptobenzothiazole, benzotriazole, and 8-hydroxyquinoline, respectively.

[0063] Examples 10-11

[0064] The preparation method is basically the same as that in Example 1, the only difference being that the encapsulating compounds are mercaptopropylsilsesquioxane and tetramercaptopropylsilane, respectively.

[0065] Comparative Example 1

[0066] The preparation method is basically the same as in Example 1, the only difference being that the ratio of the encapsulated compound is 0.5 mmol of encapsulated compound to 1 g of molecular sieve.

[0067] Comparative Example 2

[0068] The preparation method is basically the same as in Example 1, except that the ratio of the encapsulated compound is 2 mmol of encapsulated compound to 1 g of molecular sieve.

[0069] Comparative Example 3

[0070] Its preparation method is basically the same as that in Example 1, the only difference being that the electron beam radiation dose is 20kGY.

[0071] Comparative Example 4

[0072] Its preparation method is basically the same as that in Example 1, the only difference being that the electron beam radiation dose is 200kGY.

[0073] The formulations and parameters of Examples 1-11 and Comparative Examples 1-4 are shown in Table 1 below.

[0074] Table 1

[0075]

[0076]

[0077] The molecular sieves prepared in Examples 1-11 and Comparative Example 1 were subjected to the following parameter measurements. Specifically, to determine the average pore volume and pore size of the modified molecular sieves, the low-temperature nitrogen adsorption-desorption method (BET method) was used for characterization. First, the sample to be tested was placed in a vacuum degassing device and treated continuously under vacuum conditions at, for example, 200°C for 2 hours to thoroughly remove impurities such as moisture and gas adsorbed on the sample surface and within the pores. The treated sample was then transferred to a fully automated physical adsorption instrument and tested at 200°C.

[0078] The instrument precisely controls the relative pressure of nitrogen (P / P). N2 This causes it to gradually increase from an extremely low value (close to vacuum) to near the saturated vapor pressure (P / P). N2 ≈1), record the amount of nitrogen adsorbed by the sample under different pressures to form an adsorption isotherm; then, gradually reduce the pressure and record the amount of desorption to form a desorption isotherm.

[0079] After obtaining the complete adsorption-desorption isotherms, calculations were performed using the instrument's accompanying analytical software. First, in the linear region of the adsorption isotherm with relatively low pressure, the BET (Brunauer-Emmett-Teller) theoretical model was applied to fit the data to calculate the sample's specific surface area. Total pore volume is usually directly taken from the relative pressure P / P0. N2 =0.99 (or 0.995) corresponds to the nitrogen adsorption amount, representing the total volume when the pores are essentially filled with nitrogen. To obtain the pore size distribution and average pore size, the desorption curve branches are mainly analyzed (because for mesoporous materials with narrow pore size distributions, the desorption branches better reflect the true pore size information), and the BJH (Barrett-Joyner-Halenda) model is applied for calculation. This model, based on the capillary condensation principle, can convert the desorption amount under different pressures into the corresponding pore size and distribution, ultimately obtaining the pore size distribution curve. From this, the most probable pore size (the pore size corresponding to the distribution peak) or the volume average pore size can be read or calculated. Simultaneously, based on the measured specific surface area and total pore volume, the average pore size can also be estimated as a reference using simple geometric relationships (such as the cylindrical pore model formula). The entire analysis process requires considering the shape of the adsorption-desorption curve (such as the type of hysteresis loop) to comprehensively judge the characteristics and orderliness of the pore structure. Examples of specific surface area, pore volume, and pore size are shown below. Figures 2-4 As shown.

[0080] The specific surface area, pore volume, and pore diameter of Examples 1-11 and Comparative Examples 1-4 are shown in Table 2.

[0081] Table 2

[0082]

[0083]

[0084] The corrosion resistance of the molecular sieve of this invention

[0085] The molecular sieves prepared in Examples 1-11 and Comparative Examples 1-4 were subjected to corrosion resistance tests. The specific experimental steps are as follows:

[0086] The initial steps of the experiment require sample preparation, electrolyte preparation, and the setup of a three-electrode system. In the sample preparation stage, Q235 steel substrate is cut into 10cm × 10cm square samples, polished with sandpaper ranging from 400# to 2000# until a mirror finish is achieved, ultrasonically cleaned with anhydrous ethanol for 10 minutes to remove surface contaminants, and then dried before uniformly coating with a target coating. This coating is formulated with an organic matrix containing 25% PDMS and 75% DMS, and 5% of the aforementioned molecular sieve corrosion inhibitor. After stirring, the coating solution is applied to the Q235 steel surface as a uniform 50-micron wet film and cured at 80℃ for 24 hours.

[0087] Copper wires were soldered to the back of the sample for electrical connection, and the non-test area was sealed with epoxy resin, with only 1 cm exposed. 2 The coating surface serves as the working area. The electrolyte is a 3.5 wt% NaCl solution (simulating a seawater environment), prepared with deionized water and analytical grade NaCl. After standing for 24 hours, high-purity nitrogen is purged for 30 minutes before testing to remove dissolved oxygen (in an aerobic environment, air is used instead). In the three-electrode system setup, the working electrode (WE) is the coating / Q235 steel sample under test, the reference electrode is a saturated calomel electrode (SCE), and the counter electrode (CE) is a platinum sheet. The capillary tip of the reference electrode should be approximately 2 mm from the working electrode surface to minimize the influence of solution resistance. The electrolytic cell is placed in a constant temperature water bath at 25 ± 1 °C.

[0088] After immersing the working electrode in the electrolyte, start the electrochemical workstation and select the open circuit potential-time (OCP vs. t) mode to continuously monitor the potential change. Significant potential fluctuations are observed within the initial 30–60 minutes. Once the potential stabilizes (defined as fluctuations ≤ ±2 mV within 15 minutes), record the final stable value; this potential is the corrosion potential.

[0089] After the open-circuit potential stabilizes, switch to the potentiodynamic polarization scanning mode. Set the scanning range to ±250 mV relative to the corrosion potential, such as from a corrosion potential minus 250 mV to a corrosion potential plus 250 mV. The scanning rate is fixed at 10 mV per minute, and the data acquisition density is no less than one data point per mV. After starting the scan, the instrument automatically records the current-potential curve. After the scan is completed, use analysis software to perform linear fitting on the Tafel region of the anode and cathode, typically within a 50 mV range of corrosion potential. The potential value corresponding to the intersection of the two fitted lines is used to verify the corrosion potential. The current density at the intersection is normalized by area to obtain the corrosion current density, expressed in amperes per square centimeter (A / cm²). 2 ).

[0090] After completing the potentiodynamic polarization test, switch to linear polarization mode at the same stable potential. Set the scan range to ±10 mV relative to the corrosion potential (e.g., from corrosion potential minus 10 mV to corrosion potential plus 10 mV), and set the scan rate to 0.1 mV / s to suppress capacitor current interference. After obtaining the linear potential-current curve, select a range of ±5 mV near the open circuit potential to calculate the slope of the curve. Divide the voltage change by the current change. Multiply this slope by the square centimeter area of ​​the working electrode to obtain the polarization resistance, in ohm square centimeters (Ω·cm). 2 ).

[0091] The specific anti-corrosion effects are shown in Table 3.

[0092] Table 3

[0093]

[0094] Structural analysis of the molecular sieve prepared in this invention

[0095] Fourier transform infrared spectroscopy was performed on the molecular sieves prepared in Examples 1-4 above, and the results are as follows: Figure 5 As shown, from Figure 5 The results show the successful introduction of the vinyl site and the encapsulation of the two corrosion inhibitor molecules, as well as the signal associated with tetramercaptopentaerythritol ester.

[0096] Furthermore, X-ray diffraction experiments were conducted, and the X-ray powder diffraction pattern is as follows: Figure 6 As shown in the figure, after modification and radiation encapsulation, the characteristic peak signal at 2° of SBA-15 is significantly weakened, while the organic amorphous peak at 22° is somewhat enhanced, indicating that its pores are smaller and the organic portion is more abundant.

[0097] Elemental analysis Figure 7 Similarly, it was shown that the content of the organic part of SBA-15 increased significantly after modification and encapsulation, and the grafting rate (with S element reference) showed a trend of first increasing and then decreasing with increasing dosage.

[0098] It should be noted that this application is not limited to the above-described embodiments. The above embodiments are merely examples, and any embodiments with the same structure and effect as the technical concept within the scope of this application are included in the technical scope of this application. Furthermore, various modifications that can be conceived by those skilled in the art to the embodiments, and other ways of constructing by combining some of the constituent elements of the embodiments, without departing from the spirit of this application, are also included in the scope of this application.

Claims

1. A molecular sieve encapsulated with a corrosion inhibitor, comprising: Molecular sieves; Corrosion inhibitor, wherein the corrosion inhibitor is encapsulated inside the molecular sieve; The specific surface area of ​​the molecular sieve is 1–20 m². 2 / g, average pore volume is 0.5~1.5cm³ 3 / g, and an average pore size of 5–15 nm.

2. The molecular sieve according to claim 1, characterized in that, The molecular sieve satisfies at least one of the following three conditions: Specific surface area is 4.0–11.2 m². 2 / g: The average pore volume is 0.8–1.2 cm³. 3 / g; or The average pore size is 8–12 nm.

3. The molecular sieve according to claim 1 or 2, characterized in that, The molecular sieve is a silicon-based molecular sieve.

4. The molecular sieve according to claim 1 or 2, characterized in that, The corrosion inhibitor may be selected from one or more of the following corrosion inhibitors: 2-Mercaptobenzothiazole, benzotriazole, tolyltriazole, 5-methylbenzotriazole, 2-mercaptobenzoimidazol, 8-hydroxyquinoline, 2-mercaptobenzoxazole, 1-hydroxybenzotriazole, 2-aminopyrimidine, 2-mercapto-1,3,4-thiadiazole, or mercaptoacetic acid.

5. The molecular sieve according to claim 1 or 2, characterized in that, The encapsulating compound may be selected from one or more of the following encapsulating compounds: It is tetramercaptopentaerythritol ester, bis(3-mercaptopropyl)dimethoxysilane, mercaptopropylsilsesquioxane, tetramercaptopropylsilane, or tris(3-mercaptopropyl)trimethoxysilane.

6. A method for preparing a molecular sieve encapsulated with a corrosion inhibitor, comprising the following steps: S1. Preparation of molecular sieves modified with vinyl sites; S2, The molecular sieve obtained in step S1 and the corrosion inhibitor are subjected to electron beam irradiation together; and S3. The molecular sieve obtained in step S2 is filtered, washed and dried to finally prepare a molecular sieve encapsulated with a corrosion inhibitor.

7. The preparation method according to claim 6, characterized in that, In step S2, the dose range of the electron beam is 1–500 kGy, preferably 1–200 kGy, and more preferably 60–150 kGy.

8. The preparation method according to claim 6 or 7, characterized in that, Step S2 also includes the encapsulation compound being irradiated by an electron beam along with the molecular sieve and corrosion inhibitor.

9. The preparation method according to claim 6, characterized in that, The mass ratio of the encapsulated compound to the molecular sieve is preferably 0.5–1.5 mmol / g, more preferably 0.6–1.2 mmol / g, and even more preferably 1.0 mmol / g.

10. A coating comprising a molecular sieve as described in any one of claims 1 to 5 or a molecular sieve prepared by any one of claims 6 to 9.

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