A method for preparing an intrinsically self-healing shape memory anti-corrosion and microwave absorbing coating

Abstract

A method for preparing an intrinsically self-healing shape memory anti-corrosion and microwave absorbing coating is disclosed. The method uses CIP (carbon-in-polypropylene) as an emulsifier and polyurethane and melamine resin as organic shells to form a stable sandwich-structured microcapsule. After high-temperature sintering, the organic shell transforms into carbon material to coat and dope the CIP. The synergistic effect of the carbon-based and metal-based materials effectively improves the microwave absorption performance of the material. Simultaneously, it possesses excellent superhydrophobic properties, effectively blocking corrosive media from contacting the particles. Through the innovative development of amine curing agents containing diselenide bonds, self-healing and shape memory properties can be effectively introduced into the coating substrate. The shape memory effect facilitates the physical repair of cracks, while the self-healing mechanism enables chemical repair of external damage. The synergistic effect of these two factors further ensures the excellent anti-corrosion and microwave absorbing performance of the entire coating.

Description

TECHNICAL FIELD

[0001] The application relates to a preparation method of a corrosion-resistant wave-absorbing coating, in particular to a preparation method of a shape memory corrosion-resistant wave-absorbing coating with intrinsic self-repairing. BACKGROUND

[0002] Metal materials are widely used in the fields of ocean, chemical industry, transportation, aerospace, etc., however, they are easily corroded in various complex environments, causing huge economic losses and safety hazards. The traditional solution is to use organic coatings to protect them, but defects such as micropores and cracks are easily generated in the coating curing process, so that the corrosion medium penetrates the coating and causes metal corrosion, resulting in protection failure. Therefore, increasing the corrosion resistance of materials and improving the durability and protection effect of coatings through various means is an important research topic at present.

[0003] In addition, higher requirements for the wave-absorbing performance of materials are put forward in modern military to realize radar stealth and other functions, which is mainly realized by adding wave-absorbing particles or using wave-absorbing materials. The wave-absorbing material is a material capable of absorbing or greatly weakening the electromagnetic wave energy received on its surface, which converts electromagnetic wave energy into heat or other forms of energy and is consumed, thereby reducing the interference of electromagnetic waves. Such materials require high absorption rate, light weight, temperature resistance, humidity resistance, corrosion resistance and other properties in engineering applications to ensure that they have high absorption rate to electromagnetic waves within a wide frequency band, while having good impedance matching characteristics and attenuation characteristics, so that reflectivity, scattering rate and transmittance are minimized. However, current commercial wave-absorbing materials are also easily corroded in complex environments, causing a decrease in wave-absorbing performance. Therefore, it is of great significance to develop materials with both corrosion resistance and wave-absorbing function by introducing various means such as using self-repairing materials and introducing super-hydrophobic properties, to improve the stealth performance and reliability of equipment. SUMMARY

[0004] The application aims to solve the problems of poor corrosion resistance of existing metal materials or wave-absorbing materials, and provides a preparation method of a shape memory corrosion-resistant wave-absorbing coating with intrinsic self-repairing.

[0005] To achieve the above-mentioned purpose, the technical scheme adopted by the application is as follows:

[0006] A preparation method of a shape memory corrosion-resistant wave-absorbing coating with intrinsic self-repairing, the method comprises the following steps:

[0007] Step 1: Preparation of capsule particles containing an inner core: Dissolve 5-15g of carbonyl iron (CIP) in 50-150mL of water and mechanically stir at 300-1000rpm for 1-10min to obtain a CIP suspension; In another container, at 50-100℃, dissolve 5-15g of isocyanate monomer with a functionality of 2 or higher in a mixture of 5-20g of an oily solvent and 5-20g of tetraethyl or tetraethyl titanate. In the preparation, the CIP suspension is mixed with the above mixed solution, emulsified for 20-50 min, then 0.3-1.0 g of m-phenylenediamine is added, stirred for 3-10 min, heated to 50-80℃, reacted for 10-50 min, then 0.5-2 g of diamine compound is added, and the reaction is carried out for 5-16 h. After the reaction is completed, the mixture is sieved, filtered, and dried to obtain capsule particles containing an inner core. In this step, the cyanate groups and amine groups undergo interfacial polymerization to generate a polyurethane organic shell.

[0008] Step 2: Preparation of sandwich-structured capsule particles

[0009] Preparation of melamine resin prepolymer: Mix 2-10g formaldehyde, 0.5-5g melamine, and 5-15g H2O, adjust the pH to 8-9, and react magnetically at 50-80℃ and 100-500rpm in a constant temperature water bath for 0.5-3h to obtain a prepolymer solution; In another container, dissolve 6-13g of the above-mentioned capsule particles containing the inner core in 50-180mL of water, and mechanically stir at 300-600rpm to obtain a suspension. Add the above-mentioned melamine resin prepolymer to the suspension, stir for 1-10min, add 0.2-0.8g citric acid, and react at 50-80℃ for 5-12h to obtain sandwich-structured capsule particles; Melamine resin polymerization mechanism: The synthesis reaction mechanism of melamine resin is the condensation reaction between aldehyde compounds and amines. Under alkaline conditions, aldehyde compounds undergo nucleophilic addition reactions of the carbonyl groups to generate intermediate condensate products.

[0010] Step 3: Preparation of carbon-doped sandwich capsule particles: The sandwich structure capsule particles are sintered in a tube furnace under an argon atmosphere at a rate of 3-10℃ / min to 500-900℃ for 2-3 hours to obtain carbon-doped sandwich capsule particles (C@CMP).

[0011] Step 4: Preparation of Intrinsic Self-Healing High-Performance Shape Memory Anti-corrosion and Wave Absorbing Coating

[0012] A mixture of resin matrix, toughening agent and bis-selenium curing agent is prepared by adding 2wt.%-8wt.% C@CMP. The mixture is then applied by spraying, spin coating, or scraping. The coating is cured at 20-150℃ for 2-20 hours to obtain a high-performance shape memory anti-corrosion and microwave absorbing coating with intrinsic self-healing properties.

[0013] Further, in step one, the isocyanate monomer with a functionality of 2 or higher is one of polymethylene polyphenyl polyisocyanate (PAPI), diphenylmethane diisocyanate, and toluene diisocyanate.

[0014] Furthermore, in step one, the oily solvent is one of butanone, cyclohexanol, cyclohexanone, and isophorone.

[0015] Furthermore, in step one, the diamine compound is one of m-phenylenediamine, o-phenylenediamine, and p-phenylenediamine.

[0016] Furthermore, in step two, the pH adjuster is triethanolamine or dipropylene glycolamine.

[0017] Furthermore, in step four, the resin matrix is ​​epoxy E44, E51, TDE85, etc., and the toughening agent is polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, etc.

[0018] Further, in step four, the preparation method of the diselenamine curing agent is as follows: Take a 250mL three-necked flask, add a magnetic flask and 2-10g of selenium powder, connect it to a waste gas absorption bottle, first add 10-30mL of water, then slowly add an aqueous solution containing 1-5g of NaBH4 using a separatory funnel. After the addition is complete, react at 40-80℃ for half an hour, treat with argon gas for 2-20min, add an aqueous solution containing 5-20g of 3-bromopropylamine hydrobromide (using 5-40mL of water), then add 10-50g of THF, and react at 40-80℃ for 20-40h. After the reaction is completed, remove THF by rotary evaporation, extract and dry the product to obtain diselenamine.

[0019] The advantages of this invention compared to existing technologies are as follows: This invention proposes a novel method for preparing a high-performance anti-corrosion and microwave-absorbing coating. It innovatively uses microwave-absorbing material CIP as an emulsifier and polyurethane and melamine resin as organic shells to form a stable sandwich-structured microcapsule. After high-temperature sintering, the organic shell transforms into carbon material to coat and dope the CIP. The synergistic effect of carbon-based and metal-based materials effectively improves the microwave absorption performance of the material. Simultaneously, it possesses excellent superhydrophobic properties, effectively blocking corrosive media from contacting particles. Through the innovative development of amine curing agents containing diselenide bonds, self-healing and shape memory properties can be effectively introduced into the coating substrate. The shape memory effect facilitates the physical repair of cracks, while the self-healing mechanism enables chemical repair of external damage. The synergistic effect of these two factors further ensures the excellent anti-corrosion and microwave-absorbing performance of the entire coating. Attached Figure Description

[0020] Figure 1 A schematic diagram of the equation for the preparation of diselenoamine;

[0021] Figure 2 Contact angle photographs of the prepared sandwich-structured C@CMP particles;

[0022] Figure 3 SEM image of the sandwich structure C@CMP;

[0023] Figure 4 EDS plot of sandwich structure C@CMP;

[0024] Figure 5 Reflection loss diagrams for CIP and sandwich-structured C@CMP particles;

[0025] Figure 6 The graph shows the reflection loss of a 6 wt.% content coating (other contents are also possible);

[0026] Figure 7 Image showing the shape memory / self-healing effect of the coating;

[0027] Figure 8 Coating impedance (R) for scratch-unrepaired coating, scratch-repaired coating, and unscratched coating C Change diagram;

[0028] Figure 9 The equivalent circuit model diagram fitted to the impedance data. Detailed Implementation

[0029] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments, but it is not limited thereto. Any modifications or equivalent substitutions to the technical solution of the present invention that do not depart from the spirit and scope of the technical solution of the present invention should be covered within the protection scope of the present invention.

[0030] The coating of this invention possesses self-healing, shape memory, corrosion resistance, and wave absorption properties. Its shape memory characteristic originates from the resin matrix. The curing agent used in the shape memory resin matrix contains diselenide bonds, which exhibit excellent self-healing properties. Therefore, the matrix simultaneously endows the material with both self-healing and shape memory properties. Furthermore, this invention utilizes a sandwich-structured capsule particle design, which presents a low-surface-energy nano-rough structure that effectively traps air and forms an air film on the surface of the C@CMP particles, giving it superhydrophobic properties. Figure 3 The superhydrophobic properties of the particles, combined with the shape memory and self-healing properties of the substrate, can effectively prevent corrosion particles from eroding the coating and significantly reduce the amount of chloride ions (Cl) in the corrosive solution. - The coating contacts the surface of C@CMP particles, thereby improving the corrosion resistance of the C@CMP particles. Based on its high microwave absorption capacity, the coating also exhibits excellent anti-corrosion properties, effectively ensuring the long-term use of the coating material.

[0031] Example 1

[0032] A method for preparing an intrinsically self-healing shape memory anti-corrosion and microwave absorbing coating, the method comprising:

[0033] Step 1: Preparation of capsule particles containing an inner core: In a 250mL three-necked flask, 10g of carbonyl iron (CIP) was dissolved in 100mL of water and mechanically stirred at 500rpm for 2min to obtain a CIP suspension; In another container, 8g of PAPI (TDI+EG-8h) was dissolved in a mixed solvent consisting of 8g of cyclohexanol and 8g of tetraethyl orthosilicate (TEOS) at 80℃; The CIP suspension was mixed with the above mixed solution and emulsified for 35min, then 0.7g of m-phenylenediamine was added, stirred for 5min, and then heated to 65℃. After reacting for 20min, 1.3g of m-phenylenediamine was added, and the reaction was carried out for 8h; After the reaction was completed, the mixture was sieved and filtered (150 mesh), then filtered under vacuum and dried at 80℃ for 30min to obtain capsule particles containing an inner core; In this step, the cyanate groups and amine groups undergo interfacial polymerization to generate a polyurethane organic shell.

[0034] Step 2: Preparation of sandwich-structured capsule particles

[0035] Preparation of melamine resin prepolymer: A magnetic stir bar, 5g formaldehyde, 2g melamine, and 7.5g H2O were mixed. The pH was adjusted to 8-9 with triethanolamine. The mixture was magnetically stirred in a constant temperature water bath at 70℃ and 300rpm for 1.5h to obtain a prepolymer solution. In a separate container, 8g of the above-mentioned capsule particles (60 and 80 mesh) containing the inner core were dissolved in 100mL of water and mechanically stirred at 300-400rpm to obtain a suspension. The above-mentioned melamine resin prepolymer was added to the suspension and stirred for 2min. 0.4-0.5g citric acid was added, and the mixture was reacted at 65℃ for 9h to obtain sandwich-structured capsule particles. Melamine resin polymerization mechanism: The synthesis reaction mechanism of melamine resin is a condensation reaction between aldehyde compounds and amines. Under alkaline conditions, aldehyde compounds undergo nucleophilic addition reactions of the carbonyl groups to generate intermediate condensate products.

[0036] Step 3: Preparation of carbon-doped sandwich capsule particles: The sandwich structure capsule particles are sintered in a tube furnace under an argon atmosphere at a rate of 5℃ / min to 600℃ for 2-3 hours to obtain carbon-doped sandwich capsule particles (C@CMP).

[0037] Step 4: Preparation of Intrinsic Self-Healing High-Performance Shape Memory Anti-corrosion and Wave Absorbing Coating

[0038] Take a 250mL three-necked bottle, add a magnetic magnet and 4g of selenium powder, and connect it to the waste gas absorption bottle (1mol·L⁻¹). -1Before the reaction, the permeability and airtightness of the gas path must be checked using NaOH solution (to absorb H2Se). First, add 20 mL of water, then slowly add 20 mL of aqueous solution containing 2 g of NaBH4 using a separatory funnel. After the addition is complete, react at 60 °C for half an hour, treat with argon for 5 min, add an aqueous solution containing 11 g of 3-bromopropylamine hydrobromide (using 20 mL of water), then add 25 g of THF, and react at 60 °C for 24 h. After the reaction is complete, remove THF by rotary evaporation, extract the product with dichloromethane, continuously add NaOH solution, extract, filter, and then absorb the water with anhydrous Na2SO4 to obtain diselenoamine.

[0039] Bisphenol A type epoxy resin (E44) was selected as the hard segment, polyethylene glycol diglycidyl ether (DER736) as the soft segment, and synthesized diselenoamine was used as the curing agent. The EDD3 formulation was selected, and 6% microwave absorbing particles C@CMP were added. The mixture was cured at 100℃ for 4 hours. By adjusting the ratio of hard to soft segments, a series of self-healing epoxy resins (EDDs) were successfully prepared.

[0040] Table 1 Formulation Design of Self-Healing Resin Systems

[0041] Sample EP-44 / DEG / (H2NC3H6Se)2 EP-44 / g DER736 / g (H2NC3H6Se)2 / g EDD-1 5:1:6 8.5 1.9 8.7 EDD-2 4:2:6 6.8 3.8 8.7 EDD-3 3:3:6 5.1 5.7 8.7 EDD-4 2:4:6 3.4 7.6 8.7 EDD-5 1:5:6 1.7 9.5 8.7

[0042] like Figure 2 The image shows the contact angle of the prepared sandwich-structured C@CMP particles; the contact angle is 152.5°, indicating that the obtained particles have superhydrophobic properties.

[0043] like Figure 3 Figure a shows the SEM images of the sandwich-structured C@CMP. In Figure a, the particles exhibit a regular spherical morphology without obvious breakage or collapse. This indicates that the double-layer structure significantly improves the overall rigidity and high-temperature resistance of the particles, enabling them to effectively resist morphological deformation during high-temperature carbonization and successfully maintain the integrity of the hollow core-shell structure. Figure b shows the SEM image after crushing. It can be seen that a hollow structure has formed inside, which provides favorable conditions for multiple reflections and scattering of electromagnetic waves. Furthermore, the CIP particle layers remain encased by the inner and outer shells after carbonization, which helps to form a polarization interface between the carbon-based material and the metal-based absorbing material, thereby enhancing the interfacial polarization and dipole polarization effects of the absorbing particles.

[0044] like Figure 4 The image shows the EDS diagram of the sandwich structure C@CMP. The results indicate that the final absorbing particles have a high content of Fe and C elements and a low content of O and N elements, further proving from a chemical perspective that the carbonization process resulted in the target sandwich structure C@CMP.

[0045] like Figure 5The figure shows the reflection loss diagrams of CIP and sandwich-structured C@CMP particles. CIP exhibits a maximum reflection loss of -14.94 dB at a thickness of 3.00 mm and a frequency of 16.5 GHz. C@CMP reaches a maximum reflection loss of -56.96 dB, corresponding to a thickness of 3.00 mm and a frequency of 8.48 GHz. This indicates that the sandwich structure of C@CMP effectively improves the particle's absorption performance.

[0046] like Figure 6 The figure shows the reflection loss diagram for a 6 wt.% C@CMP coating. When the C@CMP content is 6%, the maximum reflection loss value at a coating thickness of 4 mm is RL. max = -54.14dB, corresponding to a frequency of 9.76GHz, indicating that the coating prepared using sandwich-structured C@CMP particles has excellent wave absorption characteristics.

[0047] like Figure 7 The image shown illustrates the shape memory / self-healing effect of the coating. After scratch treatment, the scratches are further treated at 70℃. At this temperature, two effects occur simultaneously: firstly, based on the shape memory properties of the substrate material, the shape recovers, and the scratch crack is physically reduced; secondly, due to the self-healing effect of the diselenium bonds, -Se-Se- bond exchange occurs, completing the chemical self-healing process. The macroscopic manifestation is shown below. Figure 7 As shown.

[0048] To better understand the corrosion behavior of scratch-unrepaired coatings, scratch-repaired coatings, and unscratched coatings, an equivalent circuit model was used to fit the EIS data of the three coatings. Figure 9 ), where R s and R c These represent solution resistance and coating resistance, respectively; the coating capacitor is a constant phase element using CPE. c It is stated that CPE dl As a constant-phase element of a double-layer capacitor, R ct This represents the charge transfer resistance.

[0049] Coated resistor (R) c It is also an important parameter for evaluating the protective performance of coatings, and its changes reflect the penetration behavior of corrosive media. For example... Figure 8 As shown, the initial R of the three coatings c The values ​​are 2.14 x 10. 8 Ω·cm 2 4.17x10 8 Ω·cm 2 and 4.47x10 8 Ω·cm 2 Because the scratches were not repaired, the scratch-unrepaired C@CMP coating resistance (R) is... cSlightly lower. After 35 days of corrosion, the R of scratch-repaired and unscratched C@CMP coatings was... c The values ​​decreased to 2.24x10. 7 Ω·cm 2 2.75x10 7 Ω·cm 2 The equivalent circuit model remained R(CR) throughout the entire corrosion immersion process, indicating that the absorbing particles C@CMP in the coating did not undergo significant corrosion. However, for the scratch-unrepaired C@CMP coating, after 21 days of corrosion, the coating's R... c The values ​​decreased to 4.62x10. 6 Ω·cm 2 The equivalent circuit model changes from R(CR) to R(RC(CR)), and the absorbing particles C@CMP are corroded. By day 35 of corrosion, R... c The value dropped rapidly to 9.22 x 10⁻⁶. 4 Ω·cm 2 At this point, the unrepaired C@CMP coating suffered severe corrosion, which is related to the low-frequency impedance modulus |Z| of the three coatings. f＝0.01Hz The coating changes were consistent. These results indicate that the C@CMP coating possesses excellent self-healing properties and can effectively inhibit the corrosive effects of corrosive media on the coating.

[0050] Example 2

[0051] A method for preparing an intrinsically self-healing shape memory anti-corrosion and microwave absorbing coating, the method comprising:

[0052] Step 1: Preparation of capsule particles containing an inner core: In a 250mL three-necked flask, 10g of carbonyl iron (CIP) was dissolved in 100mL of water and mechanically stirred at 500rpm for 2min to obtain a CIP suspension; In another container, 8g of toluene diisocyanate was dissolved in a mixed solvent consisting of 8g of cyclohexanone and 8g of tetraethyl orthosilicate (TEOS) at 80℃; The CIP suspension was mixed with the above mixed solution and emulsified for 35min, then 0.7g of m-phenylenediamine was added, stirred for 5min, and then heated to 65℃. After reacting for 20min, 1.3g of o-phenylenediamine was added, and the reaction was carried out for 8h; After the reaction was completed, the mixture was sieved and filtered (150 mesh), then vacuum filtered, and dried at 80℃ for 30min to obtain capsule particles containing an inner core; In this step, the cyanate groups and amine groups undergo interfacial polymerization to generate a polyurethane organic shell.

[0053] Step 2: Preparation of sandwich-structured capsule particles

[0054] Preparation of melamine resin prepolymer: A magnetic stir bar, 5g formaldehyde, 2g melamine, and 7.5g H2O were mixed. The pH was adjusted to 8-9 with dipropylene glycol amine. The mixture was magnetically stirred in a constant temperature water bath at 70℃ and 300rpm for 1.5h to obtain a prepolymer solution. In a separate container, 8g of the above-mentioned capsule particles (60 and 80 mesh) containing the inner core were dissolved in 100mL of water and mechanically stirred at 300-400rpm to obtain a suspension. The above-mentioned melamine resin prepolymer was added to the suspension and stirred for 2min. 0.4-0.5g citric acid was added, and the mixture was reacted at 70℃ for 10h to obtain sandwich-structured capsule particles. Melamine resin polymerization mechanism: The synthesis reaction mechanism of melamine resin is a condensation reaction between aldehyde compounds and amines. Under alkaline conditions, aldehyde compounds undergo nucleophilic addition reactions of the carbonyl groups to generate intermediate condensate products.

[0055] Step 3: Preparation of carbon-doped sandwich capsule particles: The sandwich structure capsule particles were sintered in a tube furnace under an argon atmosphere at a rate of 4℃ / min to 700℃ for 3 hours to obtain carbon-doped sandwich capsule particles (C@CMP).

[0056] Step 4: Preparation of Intrinsic Self-Healing High-Performance Shape Memory Anti-corrosion and Wave Absorbing Coating

[0057] Take a 250mL three-necked bottle, add a magnetic magnet and 4g of selenium powder, and connect it to the waste gas absorption bottle (1mol·L⁻¹). -1 Before the reaction, the permeability and airtightness of the gas path must be checked using NaOH solution (to absorb H2Se). First, add 20 mL of water, then slowly add 20 mL of aqueous solution containing 2 g of NaBH4 using a separatory funnel. After the addition is complete, react at 60 °C for half an hour, treat with argon for 5 min, add an aqueous solution containing 11 g of 3-bromopropylamine hydrobromide (using 20 mL of water), then add 25 g of THF, and react at 60 °C for 24 h. After the reaction is complete, remove THF by rotary evaporation, extract the product with dichloromethane, continuously add NaOH solution, extract, filter, and then absorb the water with anhydrous Na2SO4 to obtain diselenoamine.

[0058] Bisphenol A type epoxy resin (E44) was selected as the hard segment, polyethylene glycol diglycidyl ether (DER736) as the soft segment, and synthesized diselenoamine was used as the curing agent. The EDD4 formulation was selected, and 5% microwave absorbing particles C@CMP were added. The mixture was cured at 80℃ for 10 hours. By adjusting the ratio of hard to soft segments, a series of self-healing epoxy resins (EDDs) were successfully prepared.

[0059] The CIP exhibits a maximum reflection loss of -14.94 dB at a thickness of 3.00 mm and a frequency of 16.5 GHz; the C@CMP shows a maximum reflection loss of -57.78 dB, corresponding to a thickness of 3.10 mm and a frequency of 9.06 GHz. This indicates that the sandwich structure of the C@CMP effectively improves the particle absorption performance.

[0060] When the C@CMP content is 5%, the maximum reflection loss value is RL when the coating thickness is 4mm. max = -54.14dB, corresponding to a frequency of 9.76GHz, indicating that the coating prepared using sandwich-structured C@CMP particles has excellent wave absorption characteristics.

Claims

1. A method for preparing a shape memory corrosion resistant wave absorbing coating with intrinsic self-repairing, characterized in that: The method is: Step one: preparing capsule particles containing an inner core: 5-15 g of carbonyl iron is dispersed in 50-150 mL of water, and mechanical stirring treatment is performed to obtain a carbonyl iron suspension; another container is taken, 5-15 g of isocyanate monomer with a functionality of 2 or more is dissolved in a mixed solvent composed of 5-20 g of an oily solvent and 5-20 g of tetraethyl silicate or tetraethyl titanate at 50-100°C to obtain a mixed solution; the carbonyl iron suspension and the above mixed solution are mixed, emulsified for 20-50 min, then 0.3-1.0 g of m-phenylenediamine is added, stirred for 3-10 min, then heated to 50-80°C, reacted for 10-50 min, then 0.5-2 g of a diamine compound is added, and reacted for 5-16 h; after the reaction is completed, screening and filtration are performed, and drying is performed to obtain capsule particles containing an inner core; Step two: preparing sandwich structure capsule particles Preparation of melamine resin prepolymer: 2-10 g of formaldehyde, 0.5-5 g of melamine, and 5-15 g of H2O are mixed, the pH value is adjusted to 8-9, and magnetic stirring is performed at 50-80°C and 100-500 rpm in a constant temperature water bath for 0.5-3 h to obtain a prepolymer solution; another container is taken, 6-13 g of the above-mentioned capsule particles containing an inner core is dispersed in 50-180 mL of water, mechanical stirring is performed at a rotation speed of 300-600 rpm to obtain a suspension, the above-mentioned melamine resin prepolymer is added to the suspension, stirring is performed for 1-10 min, 0.2-0.8 g of citric acid is added, and reaction is performed at 50-80°C for 5-12 h to obtain sandwich structure capsule particles; Step three: preparation of carbon-doped sandwich capsule particles: the sandwich structure capsule particles are sintered in a tube furnace under an argon atmosphere at a heating rate of 3-10°C / min to 500-900°C for 2-3 h to obtain carbon-doped sandwich capsule particles; Step four: preparation of a shape memory corrosion-resistant wave-absorbing coating with intrinsic self-repairing The resin matrix, toughening agent, and diselenide curing agent are mixed, 2 wt.%-8 wt.% of the carbon-doped sandwich capsule particles are added to obtain a mixture, and a coating is prepared by spraying, spin coating, or blade coating, and is cured at 20-150°C for 2-20 h to obtain a shape memory corrosion-resistant wave-absorbing coating with intrinsic self-repairing; the diselenide curing agent is an amine curing agent containing a diselenide bond.

2. The preparation method of the shape memory anti-corrosion wave-absorbing coating with intrinsic self-repairing according to claim 1, characterized in that: In step one, the isocyanate monomer with a functionality of 2 or more is one of polymethylene polyphenyl polyisocyanate, diphenylmethane diisocyanate, and toluene diisocyanate.

3. The preparation method of the shape memory anti-corrosion wave-absorbing coating with intrinsic self-repairing according to claim 1, characterized in that: In step one, the oily solvent is one of butanone, cyclohexanol, cyclohexanone, and isophorone.

4. The preparation method of the shape memory anti-corrosion wave-absorbing coating with intrinsic self-repairing according to claim 1, characterized in that: In step one, the diamine compound is one of m-phenylenediamine, o-phenylenediamine, and p-phenylenediamine.

5. The method of claim 1, wherein the method comprises: 5.

1. preparing a solution of the shape memory corrosion resistant wave absorbing coating; 5.

2. coating the solution on a substrate; 5.

3. drying the solution to form a film; 5.

4. annealing the film; and 5.

5. removing the film from the substrate. In step two, the pH adjuster is triethanolamine or dipropylene glycol amine.

6. The method of claim 1, wherein the method comprises: 1) preparing a solution of the shape memory corrosion resistant wave absorbing coating; 2) coating the solution on a substrate; 3) drying the solution to form a film; and 4) annealing the film. In step four, the resin matrix is epoxy E44, E51, or TDE85, and the toughening agent is polyethylene glycol diglycidyl ether or polypropylene glycol diglycidyl ether.

7. The method of claim 1, wherein the method comprises: 1) preparing a solution of the shape memory corrosion resistant wave absorbing coating; 2) coating the solution on a substrate; 3) drying the solution to form a film; and 4) annealing the film. In step four, the preparation method of the bis-selenoamine curing agent is as follows: a 250 mL three-necked flask is taken, a magnet is added, 2-10 g of selenium powder is added, a waste gas absorption bottle is connected, 10-30 mL of water is added first, and then a water solution containing 1-5 g of NaBH4 is slowly dropped into a separating funnel, after the dropping is completed, 40-80 DEG C reaction is performed for half an hour, argon treatment is performed for 2-20 min, a water solution containing 5-20 g of 3-bromopropylamine hydrobromide is added, 10-50 g of THF is added, and 40-80 DEG C reaction is performed for 20-40 h; after the reaction is completed, THF is removed by rotary evaporation, the product is extracted and dried, and the bis-selenoamine curing agent is obtained.

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