Hydrogen-microorganism synergistic corrosion protection coating as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of metal corrosion protection, and discloses a hydrogen-microorganism synergistic corrosion protection coating as well as a preparation method and application thereof. The coating comprises the following components in parts by weight: 100 parts of epoxy resin, 18-22 parts of liquid polysulfide rubber, 5-7 parts of palladium modified hexagonal boron nitride nanosheets, 6-10 parts of [P4444] [Gly] coated SiO2 microcapsules, 2-4 parts of a silane coupling agent and 35-45 parts of an amine curing agent. The coating can efficiently block hydrogen permeation and inhibit microbial corrosion for a long time at the same time.

Description

Technical Field

[0001] This invention belongs to the field of metal corrosion protection technology, and more specifically, relates to a hydrogen-microorganism synergistic corrosion protection coating, its preparation method, and its application. Background Technology

[0002] In energy transmission pipeline systems, the synergistic effect of hydrogen corrosion and microbial corrosion (MIC) has become a major technical challenge threatening pipeline integrity. In hydrogen energy pipelines and sulfur-containing oil and gas pipelines, unique hydrogen corrosion problems such as hydrogen embrittlement (HE) and hydrogen-induced cracking (HIC) lead to a significant increase in the risk of pipeline corrosion and fracture. Simultaneously, the transported medium (especially those containing trace amounts of water, organic matter, or sulfates) and the soil environment provide a breeding ground for corrosive microorganisms such as sulfate-reducing bacteria (SRB) and acid-producing bacteria (APB). Their metabolic products, H2S and organic acids, create a locally highly corrosive microenvironment, accelerating pitting corrosion and cathodic depolarization processes. The interaction between the two exhibits a significant synergistic effect: H2S generated by MIC not only promotes hydrogen atom penetration, inducing sulfide stress corrosion cracking (SSCC), but also hinders the diffusion of corrosion inhibitors through biofilms, exacerbating hydrogen accumulation at defect sites; while the microcracks generated by hydrogen embrittlement further become retention areas for microbial growth, forming a vicious cycle of corrosion-hydrogen embrittlement.

[0003] Traditional anti-corrosion coatings such as epoxy and polyurethane have limited hydrogen penetration barrier capabilities and are prone to swelling, blistering, and peeling under long-term service. They also have weak inhibitory effects on microbial adhesion and biofilm formation, and are easily degraded by microorganisms. While ceramic / metal hydrogen barrier coatings such as Al2O3 and TiN possess good hydrogen barrier properties, they are brittle, their adhesion to the substrate is easily affected by stress, they offer almost no protection against microbial corrosion, and micro-defects in the coating easily become microbial initiation points. Ceramic hydrogen barrier coatings (such as Al2O3) have a flexural toughness of only 2-3 MPa·m. 1 / 2 (GB / T 21189) cannot withstand pipeline stress deformation. Some hydrogen barrier coatings use palladium-based catalysts to recombine hydrogen atoms, but the H2 generated by recombination accumulates inside the coating, forming high-pressure bubbles, leading to blistering and peeling of the coating. Some existing functionally graded coatings have acceptable hydrogen barrier effects, but they suffer from weak interlayer bonding, complex preparation processes (requiring multiple sprayings and high-temperature sintering), and difficulties in repair, making them unsuitable for on-site pipeline construction and maintenance. Antibacterial coatings mainly target microorganisms, but the antibacterial agents are easily lost, resulting in poor long-term effectiveness. They do not block hydrogen permeation, and the added metal ions (such as Cu) are also problematic. 2+ This may accelerate electrochemical corrosion.

[0004] While existing research has attempted to blend hydrogen-blocking fillers with antibacterial agents, problems such as poor interfacial compatibility, functional phase separation, and insufficient long-term effectiveness have prevented the achievement of true "hydrogen-microorganism synergistic protection." In summary, most existing technical solutions target only a single type of corrosion and cannot synergistically address the coupling problem of hydrogen permeation and microbial corrosion, or suffer from drawbacks such as complex preparation processes, insufficient mechanical properties, and poor long-term effectiveness. Therefore, there is an urgent need to develop a novel pipeline protective coating that can simultaneously block hydrogen and inhibit bacteria, while also possessing excellent mechanical properties and ease of application to ensure the safe operation of pipelines. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of existing technologies by proposing a hydrogen-microorganism synergistic corrosion protective coating, its preparation method, and its application. The coating of this invention can simultaneously and effectively block hydrogen permeation and provide long-term inhibition of microbial corrosion.

[0006] To achieve the above objectives, a first aspect of the present invention provides a hydrogen-microbial synergistic corrosion protective coating, the coating comprising the following components by weight: 100 parts epoxy resin, 18-22 parts liquid polysulfide rubber, 5-7 parts palladium-modified hexagonal boron nitride nanosheets, [P 4444 [Gly]@SiO2 microcapsules 6-10 parts, silane coupling agent 2-4 parts and amine curing agent 35-45 parts.

[0007] The coating of this invention achieves highly efficient inhibition of both hydrogen permeation and microbial corrosion through the synergistic effect of the following core inventive points: (1) Three-way interpenetrating network structure This invention is the first to construct a continuous, covalently interpenetrating network structure of "hydrogen barrier - microbial inhibition - resin matrix" within a single coating. The hydrogen barrier phase forms continuous hydrogen atom recombination channels, the microbial inhibition phase releases bactericides at phase points, and the interpenetrating network of the resin matrix provides elastic buffering. This three-phase interpenetrating network structure avoids the interface failure problem of multilayer coatings, achieving deep synergy and long-term stability of hydrogen barrier and microbial inhibition functions.

[0008] (2) Hydrogen atom “capture-recombination-lateral escape” mechanism

[0009] Palladium (Pd)-modified hexagonal boron nitride (h-BN) nanosheets (Pd@h-BN) were used as hydrogen atom recombination centers. The Pd catalytic sites facilitated the recombination of H atoms into H2, while the nanosheets blocked the diffusion path of H2 molecules. Utilizing the two-dimensional planar conductivity of the h-BN nanosheets, the H2 generated by the palladium-catalyzed recombination was laterally guided along the h-BN nanosheets to the coating edge for directional escape. Simultaneously, the h-BN nanosheets dispersed the internal stress of the coating, preventing stress concentration caused by vertical accumulation.

[0010] (3) Sustained-release ionic liquid microcapsules (i.e., the aforementioned intelligent inhibition of biomembranes)

[0011] This invention designs a tetrabutylphosphine glycinate microcapsule ([P4444][Gly]@SiO2), with a mesoporous SiO2 shell layer that controls the slow and controlled release of ionic liquid through size effect (pore size 3.5±0.5nm) to achieve the aforementioned intelligent inhibition; the core is a tetrabutylphosphine glycinate ([P4444][Gly]) ionic liquid, which achieves long-term antibacterial effect by interfering with the ion channels of biomembranes.

[0012] (4) High-toughness room temperature curing system

[0013] An interpenetrating polymer network (IPN) is formed by combining epoxy resin (EP) and liquid polysulfide rubber (PSR) under the action of an amine curing agent. This polymer network system combines the rigidity and chemical resistance of EP with the flexibility of PSR, giving the coating excellent adhesion and high toughness. It can maintain good flexibility and impact resistance at low temperature (-5℃) and adapt to the installation stress and operational deformation of oil and gas pipelines or hydrogen energy pipelines.

[0014] According to the present invention, preferably, the palladium metal particles in the palladium-modified hexagonal boron nitride nanosheets have a particle size of 6-10 nm, and the loading of the palladium metal particles is 4.8-5.2 wt% based on the total weight of the palladium-modified hexagonal boron nitride nanosheets.

[0015] According to the present invention, preferably, the method for preparing the palladium-modified hexagonal boron nitride nanosheets includes: h-BN nanosheet exfoliation: Hexagonal boron nitride powder was mixed with acid solution and stirred (magnetically stirred at 60±2℃ for 6±0.5 hours, stirring rate 300-350rpm), followed by centrifugation, washing with water (to neutrality), and vacuum drying (60±5℃, 12±0.5 hours) to obtain h-BN nanosheets. Pd loading: The h-BN nanosheets were mixed with water and ultrasonically dispersed (25-35 min) to obtain a dispersion; under a protective atmosphere (nitrogen), the dispersion was mixed with PdCl2 aqueous solution and stirred (25℃, 500 rpm, stirring for 2±0.5 hours) to obtain a mixed system; NaBH4 aqueous solution was added dropwise (controlling the dropping rate to 2 mL / min) into the mixed system to carry out a reduction reaction, and after washing and vacuum drying (60±5℃, 7-9 hours), the palladium-modified hexagonal boron nitride nanosheets were obtained.

[0016] According to the present invention, preferably, the thickness of the h-BN nanosheet is 3-7 nm.

[0017] In the h-BN nanosheet exfoliation step, the acid solution is a mixture of concentrated sulfuric acid aqueous solution and concentrated nitric acid aqueous solution, and the volume ratio of concentrated sulfuric acid aqueous solution to concentrated nitric acid aqueous solution is 3:1.

[0018] According to the present invention, preferably, the [P] 4444 The diameter of the [Gly]@SiO2 microcapsules is 160-200nm.

[0019] According to the present invention, preferably, the [P] 4444 The mesoporous SiO2 outer shell layer of the [Gly]@SiO2 microcapsules has a thickness of 20-30 nm, a coverage rate of 80-85%, and a pore size of 3-4 nm.

[0020] According to the present invention, preferably, the [P] 4444 The preparation methods of [Gly]@SiO2 microcapsules include: Preparation of ionic liquid: Tetrabutylphosphine bromide, glycine, and water were mixed and reacted under light-protected conditions (60±2℃, 24 hours). The mixture was then subjected to rotary evaporation and vacuum drying (60±2℃) to obtain tetrabutylphosphine glycinate ([P... 4444 [Gly]); Microencapsulation: The tetrabutylphosphine glycinate was mixed with anhydrous ethanol to obtain an ethanol solution of tetrabutylphosphine glycinate; the ethanol solution of tetrabutylphosphine glycinate was mixed with an aqueous solution of hexadecyltrimethylammonium bromide (CTAB) (clarified solution) and homogenized (10000 rpm, 15±3 min) to obtain an emulsion; the emulsion, tetraethyl orthosilicate (TEOS) and alkaline solution (ammonia water) were mixed (pH of the mixture was 10.3-10.7) and reacted (in a high-pressure reactor, 0.5±0.05 MPa, 100±5℃, 6±0.5 h), and then centrifuged, washed, and calcined (calcined at 550±10℃ for 2±0.2 h to remove CTAB) to obtain the [P 4444 [Gly]@SiO2 microcapsules.

[0021] A second aspect of the present invention provides a method for preparing the aforementioned hydrogen-microbial synergistic corrosion protective coating, the method comprising the following steps: S1: Mix and stir the preheated epoxy resin and preheated liquid polysulfide rubber to obtain the base material; S2: Under an ice-water bath, the base material, palladium-modified hexagonal boron nitride nanosheets, and [P] 4444 [Gly]@SiO2 microcapsules were mixed and ultrasonically dispersed to obtain a mixture; S3: Mix and stir the mixture with the silane coupling agent to obtain a crosslinked material; S4: Mix and stir the crosslinking material with the amine curing agent to obtain the hydrogen-microorganism synergistic corrosion protection coating.

[0022] According to the present invention, preferably, in step S1: The preheating temperature of the epoxy resin and the liquid polysulfide rubber is 55-65℃ and the preheating time is 5-15min, respectively. The stirring speed is 2800-3200 rpm, the time is 25-35 min, and the temperature is 55-65℃.

[0023] According to the present invention, preferably, in step S2: The ultrasonic dispersion power is 550-650W, with a 1-second pause after every 2 seconds of operation. The total ultrasonic dispersion time is 25-35 minutes, and the ultrasonic dispersion temperature is controlled to be ≤45℃ by the ice-water bath.

[0024] According to the present invention, preferably, in step S3: the stirring speed is 750-850 rpm and the time is 5-15 min.

[0025] According to the present invention, preferably, in step S4: the stirring speed is 650-750 rpm and the time is 10-20 min.

[0026] The third aspect of the present invention provides the application of the aforementioned hydrogen-microbial synergistic corrosion protective coating in the preparation of protective coatings for pipelines, wherein the pipelines are oil and gas pipelines or hydrogen energy pipelines.

[0027] According to the present invention, preferably, the method for preparing the protective coating includes: spraying the hydrogen-microbial synergistic corrosion protective coating (using an airless spraying device with a spraying pressure of 20±0.5MPa) onto the surface of a sandblasted pipe, followed by curing to obtain the protective coating.

[0028] According to the present invention, preferably, the curing temperature is 20-27°C and the curing time is 48 hours, or the curing temperature is 37-45°C and the curing time is 8 hours.

[0029] According to the present invention, preferably, the wet film thickness of the protective coating is 320-370 μm, and the dry film thickness of the protective coating is 280-320 μm.

[0030] The beneficial effects of the technical solution of the present invention are as follows: 1. The coating of the present invention constructs a three-way interpenetrating network structure of "hydrogen barrier - microbial inhibition - resin matrix" to achieve synergistic effects of hydrogen atom catalytic recombination and escape and intelligent inhibition of biofilm. It also has excellent adhesion, toughness and environmental resistance. It can simultaneously solve the coupling effect of hydrogen permeation and microbial corrosion (MIC). It can simultaneously and efficiently block hydrogen permeation (hydrogen barrier) and inhibit microbial corrosion (bacteriostasis). It is especially suitable for high-risk and harsh corrosive service environments where hydrogen-containing media and sulfate-reducing bacteria (SRB) coexist.

[0031] 2. The coating of the present invention is suitable for preparing protective coatings for oil and gas pipelines or hydrogen energy pipelines, specifically: Superior synergistic protective performance: The coating of this invention achieves dual high-efficiency inhibition of hydrogen permeation and microbial corrosion, exhibiting comprehensive protective capabilities far superior to single-function coatings; Excellent overall performance: The coating formed by the coating of the present invention has extremely high adhesion, extremely low hydrogen permeability, long-lasting antibacterial properties, excellent salt spray resistance, and good toughness and impact resistance. Long-term stability: The sustained-release ionic liquid microcapsules of the present invention ([P) 4444 The [Gly]@SiO2 microcapsules ensure the long-term effective release of the antibacterial agent, and the three-interpenetrating network structure ensures the structural integrity and functional stability of the coating during long-term service. Construction convenience: The coating of this invention can be cured at room temperature, the raw materials are readily available, and the preparation process is mature. It is particularly suitable for on-site construction, maintenance and repair of pipeline projects, and has significant engineering application value and industrialization prospects.

[0032] Other features and advantages of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0033] The above and other objects, features and advantages of the present invention will become more apparent from the more detailed description of exemplary embodiments of the invention in conjunction with the accompanying drawings.

[0034] Figure 1 A schematic diagram of the preparation process of a hydrogen-microbial synergistic corrosion protective coating and protective coating provided in Embodiment 1 of the present invention is shown.

[0035] Figure 2 The electrochemical hydrogen permeation curves of the coatings of Example 1 and Comparative Examples 1-3 in a corrosive medium containing 5% SRB are shown.

[0036] Figure 3 The images show a comparison of the surface morphology of the coatings in Example 1 and Comparative Examples 1-3 after 2000 hours of salt spray testing. Detailed Implementation

[0037] Preferred embodiments of the invention will now be described in more detail. While preferred embodiments of the invention are described below, it should be understood that the invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that the invention will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

[0038] In the following examples and comparative examples: h-BN powder, manufacturer: Momentive, model: PTX60, purity >99.5%, particle size: 1-2μm; H2SO4, Sinopharm Group, analytical grade, 98wt; HNO3, Aladdin, analytical grade, 68 wt; PdCl2 aqueous solution, Guizhou Platinum Industry Co., Ltd., Pd content 59.8%; NaBH4, Sigma-Aldrich, ≥96%; Tetrabutylphosphine bromide, P 4444 Br, TCI, >99%; Glycine, Gly, Sigma-Aldrich, >99%; Tetraethyl orthosilicate, TEOS, Sinopharm Group, 28.4% SiO2; Hexadecyltrimethylammonium bromide, CTAB, Aladdin, >99%; Epoxy resin, E51, Nantong Xingchen, epoxy value 0.51; Liquid polysulfide rubber, JLY-124, Shaanxi Petrochemical, mercapto value 0.8%; Silane coupling agent, KH-560, Nanjing Shuguang, γ-glycidyl etheroxypropyltrimethoxysilane; Amine curing agent, T-31, Huntsman, amine value 460-480 mgKOH / g.

[0039] Example 1

[0040] This embodiment provides a hydrogen-microbial synergistic corrosion protective coating, the coating comprising the following components by weight: 100 parts epoxy resin, 20 parts liquid polysulfide rubber, 6 parts palladium-modified hexagonal boron nitride nanosheets, [P 4444 [Gly]@SiO2 microcapsules 8 parts, silane coupling agent 3 parts and amine curing agent 40 parts.

[0041] The palladium metal particles in the palladium-modified hexagonal boron nitride nanosheets have a particle size of 6-10 nm, and the loading of the palladium metal particles is 5 wt% based on the total weight of the palladium-modified hexagonal boron nitride nanosheets. The method for preparing the palladium-modified hexagonal boron nitride nanosheets includes: h-BN nanosheet exfoliation: 5g of hexagonal boron nitride (h-BN) powder was added to 200mL of acid solution (concentrated H2SO4:concentrated HNO3 volume ratio = 3:1), and magnetically stirred at 60℃ for 6 hours (300-350rpm); after the end of the process, the nanosheets were centrifuged, washed with deionized water until neutral (pH=7.0), and vacuum dried at 60℃ for 12 hours to obtain h-BN nanosheets with a thickness of 3-7nm. Pd loading: 1 g of the above h-BN nanosheets were dispersed in 200 mL of deionized water and sonicated for 30 minutes to obtain a dispersion. Then, 12.5 mL of 0.1 mol / L PdCl2 aqueous solution was added to the dispersion (so that the mass ratio of Pd metal to h-BN nanosheets was about 5:100). The mixture was stirred at 500 rpm for 2 hours under N2 protection at 25 °C to obtain a mixed system. Then, 50 mL of 0.5 mol / L NaBH4 aqueous solution was slowly added dropwise to the obtained mixed system (controlling the dropping rate to about 2 mL / min) to carry out the reduction reaction. After the reaction was completed, the mixture was first centrifuged and washed, then washed three times with ethanol, and dried under vacuum at 60 °C for 8 hours to obtain the palladium-modified hexagonal boron nitride nanosheets (Pd@h-BN nanosheets).

[0042] The [P] 4444 The diameter of the [Gly]@SiO2 microcapsules is 160-200 nm; the [P] 4444 The mesoporous SiO2 outer shell layer of the [Gly]@SiO2 microcapsules has a thickness of 20-30 nm, a coverage rate of 83%, and a pore size of 3-4 nm. The [P] 4444 The preparation methods of [Gly]@SiO2 microcapsules include: Preparation of ionic liquids: 0.1 mol of tetrabutylphosphine bromide (P... 4444 Br) and 0.1 mol glycine (Gly) were dissolved in 50 mL of deionized water and reacted at 60 °C in the dark for 24 hours. After the reaction, the water was removed by rotary evaporation, and then dried under vacuum at 60 °C to obtain a white solid tetrabutylphosphine glycinate ([P 4444 [Gly]); Microcapsule encapsulation: 1g [P] 4444 [Gly] was dissolved in 20 mL of anhydrous ethanol to obtain an ethanol solution of tetrabutylphosphine glycinate; 0.5 g of hexadecyltrimethylammonium bromide (CTAB) was dissolved in 80 mL of deionized water and stirred at 60 °C until clear to obtain an aqueous solution of hexadecyltrimethylammonium bromide; the ethanol solution of tetrabutylphosphine glycinate and the aqueous solution of hexadecyltrimethylammonium bromide were mixed and homogenized at 10000 rpm for 15 minutes to obtain an emulsion; then 2 mL of tetraethyl orthosilicate (TEOS) was added dropwise to the emulsion, and the pH of the mixture was adjusted to 10.5 with ammonia; then the mixture was transferred to a high-pressure reactor and reacted at 0.5 MPa and 100 °C for 6 hours; after the reaction, it was centrifuged (8000 rpm, 5 min), washed three times with ethanol, and finally calcined at 550 °C for 2 hours to remove the template agent CTAB, to obtain mesoporous SiO2-coated ionic liquid microcapsules, i.e., the [P] 4444[Gly]@SiO2 microcapsules.

[0043] The preparation method of the hydrogen-microbial synergistic corrosion protective coating in this embodiment includes the following steps: S1 (Base Material Mixing): Epoxy resin and liquid polysulfide rubber are preheated at 60℃ for 10 minutes and then mixed. The mixture is stirred at 3000 rpm for 30 minutes, with the stirring temperature controlled at 60±5℃, to obtain the base material. S2 (filler dispersion): Palladium-modified hexagonal boron nitride nanosheets and [P] were added to the above-mentioned base material. 4444 [Gly]@SiO2 microcapsules were ultrasonically dispersed (600W power, 1-second pause after every 2 seconds of operation, total time 30 minutes), and the temperature was controlled to ≤45℃ using an ice-water bath during the process to obtain a mixture; S3 (Coupling Treatment): The mixture is mixed with the silane coupling agent and stirred (800 rpm, 10 min) to obtain a cross-linked material; S4 (Curing): The crosslinking material is mixed and stirred with the amine curing agent (850 rpm, 10 min, to ensure uniform curing of the system) to obtain the hydrogen-microorganism synergistic corrosion protection coating.

[0044] This embodiment also utilizes the hydrogen-microbial synergistic corrosion protective coating of this embodiment to prepare a protective coating for the X80 oil and gas pipeline. The preparation method includes: Substrate treatment: The X80 oil and gas pipeline substrate is sandblasted to achieve a cleanliness level of Sa2.5 and a surface roughness Ra controlled at 62μm; Spraying: Using an airless spraying device, the hydrogen-microbial synergistic corrosion protection coating of this embodiment is uniformly sprayed onto the substrate surface under a pressure of 20MPa, and the wet film thickness is controlled to be 350μm; Curing: Curing at 23-25℃ and relative humidity <75% for 48 hours forms a protective coating with a dry film thickness of approximately 300μm.

[0045] Comparative Example 1

[0046] The only difference between this comparative example and Example 1 is that it provides a basic protective coating comprising the following components by weight: 100 parts epoxy resin, 20 parts liquid polysulfide rubber, and 40 parts amine curing agent.

[0047] Comparative Example 2

[0048] The only difference between this comparative example and Example 1 is that it provides a hydrogen-blocking protective coating, which comprises the following components by weight: 100 parts epoxy resin, 20 parts liquid polysulfide rubber, 6 parts palladium-modified hexagonal boron nitride nanosheets, and 40 parts amine curing agent.

[0049] Comparative Example 3

[0050] The only difference between this comparative example and Example 1 is that it provides an antibacterial protective coating, the coating comprising the following components by weight: 100 parts epoxy resin, 20 parts liquid polysulfide rubber, [P 4444 8 parts of [Gly]@SiO2 microcapsules and 40 parts of amine curing agent.

[0051] Test case

[0052] This test example examines the protective coatings obtained in the examples and comparative examples for performance tests including adhesion, salt spray resistance, SRB antibacterial effect, effective hydrogen diffusion coefficient, and electrochemical hydrogen permeation under microbial conditions. The test methods and results are shown in Table 1. Figure 2 , Figure 3 .

[0053] Table 1

[0054] As shown in Table 1: Hydrogen permeation barrier performance: In a corrosive medium containing 5% SRB, the protective coating prepared by the coating of this invention has the lowest effective hydrogen diffusion coefficient and the best hydrogen barrier performance. Comparative Example 2 shows the second best hydrogen barrier effect, but it is still far superior to Comparative Examples 1 and 3, demonstrating the hydrogen barrier efficacy of Pd@h-BN. However, under long-term microbial conditions, Comparative Example 2, due to its lack of antibacterial ability, suffers from biofilm formation leading to coating performance degradation and a decrease in hydrogen barrier effect.

[0055] Microbial inhibition performance: The coating was subjected to an SRB antibacterial test in an anaerobic environment. The protective coating prepared by the coating of this invention, along with Comparative Example 3, achieved a Class II antibacterial effect, confirming the effectiveness of the ionic liquid microcapsules. Comparative Examples 1 and 2 showed no antibacterial ability.

[0056] Overall environmental durability: The protective coating prepared by the coating of the present invention has the longest salt spray resistance time (2000h), demonstrating the comprehensive resistance advantage of the synergistic protection system of the coating of the present invention to complex corrosive environments.

[0057] Adhesion: The protective coating prepared by the coating of the present invention has the strongest adhesion, thanks to the synergistic enhancement effect of the interpenetrating polymer network (IPN) and the silane coupling agent.

[0058] Figure 2This is a comparison of the electrochemical hydrogen permeation curves of the example and comparative coatings in a corrosive medium containing 5% SRB. According to GB / T 30074, the electrochemical hydrogen permeation test was conducted using a Devanathan-Stachurski dual-electrolysis cell. The change in current density on the hydrogen escaping side over time was monitored using an electrochemical workstation. The total thickness of the coating samples was 5.3 mm, the hydrogen charging current density was 1 mA / cm², and the hydrogen escaping side potential was 300 mV vs. SCE. Figure 2 Reading the steady-state hydrogen permeation current of the coated sample I ∞ It is 0.0094 μA·cm -2 , t 0.63 It is 7.48×10 7 s, calculate the effective diffusion coefficient of hydrogen. D =6.26×10 -10 cm 2 ·s -1 Under the same experimental conditions, the steady-state hydrogen permeation current of Comparative Example 1 (Control A) was... I ∞A ， 0.15 μA·cm -2 , t 0.63 ， It is 4.46×10 5 s, calculate the effective diffusion coefficient of hydrogen. D A ， =1.05×10 -7 cm 2 ·s -1 Steady-state hydrogen permeation current of Comparative Example 2 (Control B) I ∞B ， 0.012 μA·cm -2 , t 0.63 ， 9.00×10 6 s, calculate the effective diffusion coefficient of hydrogen. D B ， =5.20×10 -9 cm 2 ·s -1 Steady-state hydrogen permeation current of Comparative Example 3 (Control C) I ∞c ， 0.18 μA·cm -2 , t 0.63 ， It is 4.74 × 10 4s, calculate the effective diffusion coefficient of hydrogen. D c ， =9.87×10 -7 cm 2 ·s -1 As can be seen from the comparison, the coating of the present invention has a significant hydrogen barrier effect.

[0059] Figure 3 These are comparative photographs showing the surface morphology of the coatings in the examples and comparative examples after 2000 hours of salt spray testing. Figure 3 As shown, the coating of the present invention does not bubble and the scratches do not extend; in Comparative Example 1 (Control A), the scratches have peeled off at the intersection and the scratches have blistered and extended by 5 mm on one side; in Comparative Example 2 (Control B), the scratches have blistered and extended by 6 mm on one side; in Comparative Example 3 (Control C), the scratches have blistered and extended by 4 mm on one side; the coating of the present invention shows excellent salt spray resistance.

[0060] In summary, this invention constructs a three-way interpenetrating network of "hydrogen barrier-microbial inhibition-resin matrix," ensuring that the coating is not a two-component system (palladium-modified hexagonal boron nitride nanosheets, [P... 4444 This invention does not simply combine the functions of [Gly]@SiO2 microcapsules, but rather achieves deep synergy and mutual protection between the two within a robust IPN matrix through structural design. Its hydrogen barrier performance is significantly superior to a single hydrogen barrier coating (Comparative Example 2), while its antibacterial performance is also significantly superior to a single antibacterial coating (Comparative Example 3). Furthermore, it exhibits a longer durability in the harsh coupled environment of hydrogen-containing media and sulfate-reducing bacteria (SRB). This fully demonstrates that the present invention effectively solves the coupling problem of hydrogen permeation and microbial corrosion, and its comprehensive protective performance far surpasses that of existing single-function technologies, possessing outstanding novelty, inventiveness, and practical value.

[0061] The various embodiments of the present invention have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.

Claims

1. A hydrogen-microbial synergistic corrosion protective coating, characterized in that, The coating comprises the following components by weight: 100 parts epoxy resin, 18-22 parts liquid polysulfide rubber, 5-7 parts palladium-modified hexagonal boron nitride nanosheets, [P 4444 [Gly]@SiO2 microcapsules 6-10 parts, silane coupling agent 2-4 parts and amine curing agent 35-45 parts.

2. The hydrogen-microbial synergistic corrosion protective coating according to claim 1, wherein, The palladium metal particles in the palladium-modified hexagonal boron nitride nanosheets have a particle size of 6-10 nm, and the loading of the palladium metal particles is 4.8-5.2 wt% based on the total weight of the palladium-modified hexagonal boron nitride nanosheets. The method for preparing the palladium-modified hexagonal boron nitride nanosheets includes: h-BN nanosheet exfoliation: Hexagonal boron nitride powder was mixed with an acid solution and stirred, then centrifuged, washed with water, and vacuum dried in sequence to obtain h-BN nanosheets; Pd loading: The h-BN nanosheets were mixed with water and ultrasonically dispersed to obtain a dispersion; under a protective atmosphere, the dispersion was mixed with an aqueous PdCl2 solution to obtain a mixed system; an aqueous NaBH4 solution was added dropwise to the mixed system to carry out a reduction reaction, and after washing and vacuum drying, the palladium-modified hexagonal boron nitride nanosheets were obtained.

3. The hydrogen-microbial synergistic corrosion protective coating according to claim 2, wherein, The thickness of the h-BN nanosheets is 3-7 nm.

4. The hydrogen-microbial synergistic corrosion protective coating according to claim 1, wherein, The [P] 4444 The diameter of the [Gly]@SiO2 microcapsules is 160-200 nm; The [P] 4444 The mesoporous SiO2 outer shell layer of the [Gly]@SiO2 microcapsules has a thickness of 20-30 nm, a coverage rate of 80-85%, and a pore size of 3-4 nm. The [P] 4444 The preparation methods of [Gly]@SiO2 microcapsules include: Preparation of ionic liquid: Tetrabutylphosphine bromide, glycine and water were mixed and reacted under light-protected conditions. The mixture was then subjected to rotary evaporation and vacuum drying to obtain tetrabutylphosphine glycinate. Microcapsule encapsulation: The tetrabutylphosphine glycinate was mixed with anhydrous ethanol to obtain an ethanol solution of the tetrabutylphosphine glycinate; the ethanol solution of the tetrabutylphosphine glycinate was mixed and homogenized with an aqueous solution of hexadecyltrimethylammonium bromide to obtain an emulsion; the emulsion, tetraethyl orthosilicate, and alkali solution were mixed and reacted, and then subjected to centrifugation, washing, and calcination to obtain the [P] 4444 [Gly]@SiO2 microcapsules.

5. The method for preparing the hydrogen-microbial synergistic corrosion protective coating according to any one of claims 1-4, characterized in that, The preparation method includes the following steps: S1: Mix and stir the preheated epoxy resin and preheated liquid polysulfide rubber to obtain the base material; S2: Under an ice-water bath, the base material, palladium-modified hexagonal boron nitride nanosheets, and [P] 4444 [Gly]@SiO2 microcapsules were mixed and ultrasonically dispersed to obtain a mixture; S3: Mix and stir the mixture with the silane coupling agent to obtain a crosslinked material; S4: Mix and stir the crosslinking material with the amine curing agent to obtain the hydrogen-microorganism synergistic corrosion protection coating.

6. The method for preparing the hydrogen-microbial synergistic corrosion protective coating according to claim 5, wherein, In step S1: The preheating temperature of the epoxy resin and the liquid polysulfide rubber is 55-65℃ and the preheating time is 5-15min, respectively. The stirring speed is 2800-3200 rpm, the time is 25-35 min, and the temperature is 55-65℃; In step S2: The ultrasonic dispersion power is 550-650W, with a 1-second pause after every 2 seconds of operation. The total ultrasonic dispersion time is 25-35 minutes, and the ultrasonic dispersion temperature is controlled to be ≤45℃ by the ice-water bath. In step S3: The stirring speed is 750-850 rpm, and the time is 5-15 minutes; In step S4: The stirring speed is 650-750 rpm, and the stirring time is 10-20 minutes.

7. The application of the hydrogen-microbial synergistic corrosion protective coating according to any one of claims 1-4 in the preparation of a protective coating for a pipeline, wherein the pipeline is an oil and gas pipeline or a hydrogen energy pipeline.

8. The application according to claim 7, wherein, The method for preparing the protective coating includes: spraying the hydrogen-microbial synergistic corrosion protective coating onto the surface of a sandblasted pipe, and then curing it to obtain the protective coating.

9. The application according to claim 7, wherein, The curing temperature is 20-27℃ and the curing time is 48 hours, or the curing temperature is 37-45℃ and the curing time is 8 hours.

10. The application according to claim 7, wherein, The dry film thickness of the protective coating is 280-320 μm.

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