Preparation method of shape memory anti-corrosion wave-absorbing coating with intrinsic self-repairing function

Abstract

A preparation method of an intrinsic self-repairing shape memory anticorrosion wave-absorbing coating is characterized in that a wave-absorbing material CIP is used as an emulsifier, polyurethane and melamine resin are used as an organic shell, a stable microcapsule with a sandwich structure is formed, after high-temperature sintering, the organic shell is converted into a carbon material to coat and dope the CIP, and the shape memory anticorrosion wave-absorbing coating is obtained. The synergistic effect of the carbon-based and metal-based materials effectively improves the wave-absorbing performance of the material. And meanwhile, the super-hydrophobic coating has excellent super-hydrophobic property, and can effectively prevent a corrosive medium from being contacted with particles. By innovatively developing an amine curing agent containing a diselenide bond, self-repairing and shape memory properties can be effectively introduced into a coating substrate, a shape memory effect is beneficial to physical repairing of cracks and the like, a self-repairing mechanism can realize chemical repairing of external damage, and the self-repairing mechanism and the shape memory effect have a synergistic effect, so that the self-repairing effect is improved. And the excellent anti-corrosion and wave-absorbing properties of the whole coating are further ensured.

Description

Technical Field

[0001] The invention relates to a method for preparing an anti-corrosion and wave-absorbing coating, and in particular to a method for preparing a shape memory anti-corrosion and wave-absorbing coating with intrinsic self-repairing properties. Background Art

[0002] Metal materials are widely used in the fields of ocean, chemical industry, transportation, aerospace, etc. However, they are susceptible to corrosion in various complex environments, causing huge economic losses and safety hazards. The traditional solution is to use organic coatings to protect them, but during the coating curing process, micropores, cracks and other defects are easily generated, allowing the corrosive medium to penetrate the coating, causing metal corrosion and causing protection failure. Therefore, it is an important topic of current research to increase the anti-corrosion properties of materials through various means and improve the durability and protective effect of the coating.

[0003] In addition, modern military has put forward higher requirements on the wave absorption performance of materials to achieve functions such as radar stealth, which is mainly achieved by adding absorbing particles or using absorbing materials. Wave absorbing materials are materials that can absorb or greatly reduce the electromagnetic wave energy received on their surface, and consume the electromagnetic wave energy by converting it into heat or other forms of energy, thereby reducing the interference of electromagnetic waves. In engineering applications, this material is required to have high absorptivity, light weight, temperature resistance, moisture resistance, corrosion resistance and other properties to ensure that it has a high absorption rate for electromagnetic waves in a wider frequency band, and at the same time has good impedance matching characteristics and attenuation characteristics, so that the reflectivity, scattering rate and transmittance are minimized. However, commercial absorbing materials are also easily corroded in complex environments, resulting in a decrease in absorbing performance. Therefore, by introducing various means, such as using self-healing materials and introducing super-hydrophobic properties, developing materials with both anti-corrosion and wave absorbing functions is of great significance for improving the stealth performance and reliability of equipment. Summary of the invention

[0004] The purpose of the present invention is to solve the problems of poor corrosion resistance of existing metal materials or absorbing materials, and to provide a method for preparing a shape memory anti-corrosion absorbing coating with intrinsic self-repairing properties.

[0005] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0006] A method for preparing a shape memory anti-corrosion and wave-absorbing coating with intrinsic self-repairing properties, the method comprising:

[0007] Step 1: Prepare capsule particles containing an inner core: Dissolve 5-15g of carbonyl iron (CIP) in 50-150mL of water, and use mechanical stirring at a speed of 300-1000rpm for 1-10min to obtain a CIP suspension; Take another container, dissolve 5-15g of an isocyanate monomer with a functionality of 2 or more in a mixed solution consisting of 5-20g of an oily solvent and 5-20g of tetraethyl silicate (TEOS) or tetraethyl titanate at 50-100°C. agent; mixing the CIP suspension with the above mixed solution, emulsifying for 20-50 minutes, adding 0.3-1.0g of m-phenylenediamine, stirring for 3-10 minutes, heating to 50-80°C, reacting for 10-50 minutes, adding 0.5-2g of diamine compound, and reacting for 5-16 hours; after the reaction is completed, sieving and filtering, and drying to obtain capsule particles containing an inner core; in this step, the cyanate group and the amine group undergo interfacial polymerization to form a polyurethane organic shell.

[0008] Step 2: Preparation of sandwich structure capsule particles

[0009] Preparation of melamine resin prepolymer: 2-10g formaldehyde, 0.5-5g melamine, 5-15g H2O are mixed, the pH value is adjusted to 8-9, and the mixture is stirred magnetically in a constant temperature water bath at 50-80°C and 100-500rpm for 0.5-3h to obtain a prepolymer solution; in another container, 6-13g of the capsule particles containing the inner core are dissolved in 50-180mL water, and mechanically stirred at a speed of 300-600rpm to obtain a suspension, and the melamine resin prepolymer is added to the suspension, stirred for 1-10min, 0.2-0.8g citric acid is added, and the mixture is reacted at 50-80°C for 5-12h to obtain sandwich structure 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 a nucleophilic addition reaction of carbonyl groups to generate an intermediate product condensate.

[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 temperature of 3-10°C / min to 500-900°C for 2h-3h to obtain carbon-doped sandwich capsule particles (C@CMP);

[0011] Step 4: Preparation of intrinsic self-repairing high-performance shape memory anti-corrosion and microwave-absorbing coating

[0012] The resin matrix, toughening agent and diselenamine curing agent are mixed, and 2wt.%-8wt.% of C@CMP is added to obtain a mixture. The coating is prepared by spraying, spin coating, scraping, etc., and cured at 20-150°C for 2-20h to obtain a high-performance shape memory anti-corrosion and wave-absorbing coating with intrinsic self-repairing.

[0013] Furthermore, in step 1, the isocyanate monomer with a functionality of 2 or more is one of polymethylene polyphenyl polyisocyanate (PAPI), diphenylmethane diisocyanate, and toluene diisocyanate.

[0014] Furthermore, in step 1, the oily solvent is one of butanone, cyclohexanol, cyclohexanone and isophorone.

[0015] Furthermore, in step 1, the diamine compound is one of m-phenylenediamine, o-phenylenediamine and p-phenylenediamine.

[0016] Furthermore, in step 2, 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] Furthermore, in step 4, the preparation method of the diselenamine curing agent is: take a 250mL three-necked flask, add a magnetic rod, 2-10g of selenium powder, connect a waste gas absorption bottle, first add 10-30mL of water, and then use a separatory funnel to slowly drip an aqueous solution containing 1-5g of NaBH4, after the addition is complete, react at 40-80°C for half an hour, treat with argon for 2-20min, add an aqueous solution containing 5-20g of 3-bromopropylamine hydrobromide (use 5-40mL of water), and then add 10-50g of THF, and react at 40-80°C for 20-40h; after the reaction is completed, remove THF by rotary evaporation, extract and dry the product to obtain diselenamine.

[0019] The beneficial effects of the present invention compared to the prior art are as follows: the present invention proposes a new preparation method for obtaining a high-performance anti-corrosion and wave-absorbing coating, innovatively uses the wave-absorbing material CIP as an emulsifier, and uses polyurethane and melamine resin as an organic shell to form a stable sandwich structure microcapsule. After high-temperature sintering, the organic shell is converted into a carbon material to coat and dope the CIP. The synergistic effect of the carbon-based and metal-based materials effectively improves the wave-absorbing performance of the material. At the same time, it has excellent super-hydrophobic properties and can effectively block the contact of corrosive media with particles. Through the innovative development of amine curing agents containing diselenide bonds, self-repair and shape memory properties can be effectively introduced into the coating substrate. The shape memory effect is conducive to the physical repair of cracks, etc., and the self-repair mechanism can achieve chemical repair of external damage. The synergistic effect of the two further ensures the excellent anti-corrosion and wave-absorbing properties of the entire coating. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a schematic diagram of the preparation equation of diselenamine;

[0021] Figure 2 This is a contact angle photo of the prepared sandwich structure C@CMP particles;

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

[0023] Figure 4 This is the EDS image of sandwich structure C@CMP;

[0024] Figure 5 Reflection loss diagram of CIP and sandwich structure C@CMP particles;

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

[0026] Figure 7 This is the effect diagram of coating shape memory / self-healing;

[0027] Figure 8 is the coating impedance (R C ) Change graph;

[0028] Fig. 9 This is the equivalent circuit model diagram for impedance data fitting. DETAILED DESCRIPTION

[0029] The technical solution of the present invention is further described below in conjunction with the accompanying drawings and embodiments, but is not limited thereto. Any modification or equivalent replacement of the technical solution of the present invention that does not depart from the spirit and scope of the technical solution of the present invention should be included in the protection scope of the present invention.

[0030] The coating of the present invention has self-repairing, shape memory, corrosion resistance, and wave absorption properties. Its shape memory property comes from the resin matrix. The curing agent used in the shape memory resin matrix contains diselenide bonds, which have excellent self-repairing properties. Therefore, the matrix simultaneously gives the material self-repairing and shape memory properties. In addition, the present invention adopts the design of sandwich structure capsule particles, which presents a nano-micro rough structure with low surface energy, which can effectively capture air and form an air film on the surface of C@CMP particles, making it super hydrophobic ( Figure 3 ), the super-hydrophobic properties of the particles cooperate with the shape memory and self-repairing properties of the matrix to effectively prevent the corrosion of the coating by the corrosion particles, and greatly reduce the chloride ions (Cl - ) and the surface of C@CMP particles, thereby improving the corrosion resistance of C@CMP particles. The coating has excellent anti-corrosion performance based on high wave absorption ability, which effectively ensures the long-term use of the coating material.

[0031] Example 1

[0032] A method for preparing a shape memory anti-corrosion and wave-absorbing coating with intrinsic self-repairing properties, the method comprising:

[0033] Step 1: Prepare capsule particles containing an inner core: In a 250mL three-necked flask, dissolve 10g of carbonyl iron (CIP) in 100mL of water, and use mechanical stirring at a speed of 500rpm for 2min to obtain a CIP suspension; take another container, and dissolve 8g of PAPI (TDI+EG-8h) in a mixed solvent consisting of 8g of cyclohexanol and 8g of tetraethyl silicate (TEOS) at 80°C; mix the CIP suspension with the above mixed solution, emulsify for 35min, add 0.7g of m-phenylenediamine, stir for 5min, heat to 65°C, react for 20min, then add 1.3g of m-phenylenediamine and react for 8h; after the reaction is completed, sieve and filter (150 mesh), filter with suction, and dry at 80°C for 30min to obtain capsule particles containing an inner core; in this step, the cyanate group and the amine group undergo interfacial polymerization to form a polyurethane organic shell.

[0034] Step 2: Preparation of sandwich structure capsule particles

[0035] Preparation of melamine resin prepolymer: Mix a magnet, 5g formaldehyde, 2g melamine, and 7.5g H2O, adjust the pH value to 8-9 with triethanolamine, and react with magnetic stirring at 70°C and 300rpm in a constant temperature water bath for 1.5h to obtain a prepolymer solution; Take another container, dissolve 8g of the above-mentioned capsule particles containing inner core (60 and 80 mesh) in 100mL water, and mechanically stir at a speed of 300-400rpm to obtain a suspension, add the above-mentioned melamine resin prepolymer to the suspension, stir for 2min, add 0.4-0.5g citric acid, and react at 65°C for 9h to obtain sandwich structure 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 a nucleophilic addition reaction of carbonyl groups to generate intermediate product condensates.

[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 temperature of 5°C / min to 600°C for 2h-3h to obtain carbon-doped sandwich capsule particles (C@CMP);

[0037] Step 4: Preparation of intrinsic self-repairing high-performance shape memory anti-corrosion and microwave-absorbing coating

[0038] Take a 250mL three-necked flask, add a magnet and 4g of selenium powder, and connect it to a waste gas absorption bottle (1mol·L -1NaOH solution, absorb H2Se), before the reaction, be sure to test the permeability and air tightness of the gas path; first add 20mL of water, then use a separatory funnel to slowly drop in 20mL of an aqueous solution containing 2g of NaBH4, after the addition is complete, react at 60°C for half an hour, treat with argon for 5min, add an aqueous solution containing 11g of 3-bromopropylamine hydrobromide (use 20mL of water), then add 25g of THF, and react at 60°C for 24h; after the reaction is completed, remove THF by rotary evaporation, extract the product with dichloromethane, continuously add NaOH solution, extract, filter, and then use anhydrous Na2SO4 to absorb moisture to obtain diselenamine.

[0039] Bisphenol A epoxy resin (E44) was selected as the hard segment, polyethylene glycol diglycidyl ether (DER736) was selected as the soft segment, and the synthesized diselenamine was used as the curing agent. The EDD3 formula was selected, and 6% of the wave-absorbing particles C@CMP were added and cured at 100°C for 4 hours. By adjusting the ratio of the hard and soft segments, a series of epoxy resins (EDD) with self-healing properties were successfully prepared.

[0040] Table 1 Formulation design of self-healing resin system

[0041] Sample <![CDATA[EP-44 / DEG / (H2NC3H6Se)2]]> EP-44 / g DER736 / g <![CDATA[(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 , which is a contact angle photograph of the prepared sandwich structure C@CMP particles; the contact angle is 152.5°, indicating that the obtained particles have superhydrophobic properties.

[0043] like Figure 3 The figure shows the SEM image of the sandwich structure C@CMP; the particles in Figure a present a regular spherical morphology, and there is no obvious breakage or collapse, which shows that the design of 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 cavity shell core structure. Figure b is the SEM image after crushing, from which it can be seen that a cavity structure is formed inside, which provides favorable conditions for multiple reflections and scattering of electromagnetic waves, and the CIP particle layer is still covered 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 interface polarization effect and dipole polarization effect of the absorbing particles.

[0044] like Figure 4 As shown, it is the EDS image of the sandwich structure C@CMP; the results show that the Fe and C content of the finally formed absorbing particles are high; the O and N content are low, which further proves from a chemical point of view that the target sandwich structure C@CMP is formed after carbonization.

[0045] like Figure 5The figure shows the reflection loss diagram of CIP and sandwich structure C@CMP particles. When the thickness of CIP is 3.00mm and the frequency is 16.5GHz, the maximum reflection loss is -14.94dB; the maximum reflection loss of C@CMP reaches a maximum of -56.96dB, and the corresponding thickness and frequency are 3.00mm and 8.48GHz respectively. This shows that the sandwich structure of C@CMP effectively improves the wave absorption performance of the particles.

[0046] like Figure 6 As shown, it is the reflection loss diagram of the coating with 6wt.% content; when the C@CMP content is 6%, the maximum reflection loss value of the coating is RL at 4mm. max =-54.14 dB, and the corresponding frequency is 9.76 GHz, indicating that the coating prepared using sandwich structure C@CMP particles has excellent wave absorption properties.

[0047] like Figure 7 As shown in the figure, it is the effect of coating shape memory / self-healing. After scratch treatment, the scratch is treated at 70℃. Under this temperature, two effects occur at the same time. One is based on the shape memory property of the matrix material. At this temperature, the shape is restored and the scratch crack is physically reduced. At the same time, due to the self-healing effect of the diselenide bond, -Se-Se- bond exchange occurs to complete the chemical self-healing process. The macroscopic performance is as follows: Figure 7 shown.

[0048] In order to better understand the corrosion behavior of the scratch-unrepaired coating, scratch-repaired coating, and unscratched coating, an equivalent circuit model was used to fit the EIS data of the three coatings ( Fig. 9 ). Among them, R s and R c They represent solution resistance and coating resistance respectively; coating capacitance constant phase element is CPE c Indicates that CPE dl is the double layer capacitor constant phase element, R ct represents the charge transfer resistance.

[0049] Coating resistance (R c ) is also an important parameter for evaluating the protective performance of coatings, and its changes reflect the penetration behavior of corrosive media. Figure 8 As shown, the initial R c The values ​​are 2.14x10 8 Ω·cm 2 ,4.17x10 8 Ω·cm 2 and 4.47x10 8 Ω·cm 2 Since the scratches are not repaired, the scratch-unrepaired C@CMP coating resistance (R c) is slightly lower. After 35 days of corrosion, the R c The values ​​are reduced to 2.24x10 7 Ω·cm 2 , 2.75x10 7 Ω·cm 2 , the equivalent circuit model is always R(CR), and maintains a high resistance value during the entire corrosion immersion process. This shows that the absorbing particles C@CMP in the coating did not corrode significantly. However, for the scratched-unrepaired C@CMP coating, after 21 days of corrosion, the coating's R c The values ​​dropped to 4.62x10 6 Ω·cm 2 , the equivalent circuit model changes from R(CR) to R(RC(CR)), and the wave-absorbing particles C@CMP are corroded. By the 35th day of corrosion, R c The value drops rapidly to 9.22x10 4 Ω·cm 2 ,At this time, the scratch-unrepaired C@CMP coating suffers more serious corrosion, which is consistent with the low-frequency impedance modulus |Z| of the three coatings. f＝0.01Hz The coating changes are consistent. These results show that the C@CMP coating has good self-healing properties and can effectively inhibit the corrosion of the coating by the corrosive medium.

[0050] Example 2

[0051] A method for preparing a shape memory anti-corrosion and wave-absorbing coating with intrinsic self-repairing properties, the method comprising:

[0052] Step 1: Prepare capsule particles containing an inner core: In a 250mL three-necked flask, dissolve 10g of carbonyl iron (CIP) in 100mL of water, and use mechanical stirring at a speed of 500rpm for 2min to obtain a CIP suspension; take another container, and dissolve 8g of toluene diisocyanate in a mixed solvent consisting of 8g of cyclohexanone and 8g of tetraethyl silicate (TEOS) at 80°C; mix the CIP suspension with the above mixed solution, emulsify for 35min, add 0.7g of m-phenylenediamine, stir for 5min, heat to 65°C, react for 20min, then add 1.3g of o-phenylenediamine, and react for 8h; after the reaction is completed, sieve and filter (150 mesh), filter with suction, and dry at 80°C for 30min to obtain capsule particles containing an inner core; in this step, the cyanate group and the amine group undergo interfacial polymerization to form a polyurethane organic shell.

[0053] Step 2: Preparation of sandwich structure capsule particles

[0054] Preparation of melamine resin prepolymer: Mix a magnet, 5g formaldehyde, 2g melamine, and 7.5g H2O, adjust the pH value to 8-9 with dipropylene glycolamine, and react with magnetic stirring at 70°C and 300rpm in a constant temperature water bath for 1.5h to obtain a prepolymer solution; Take another container, dissolve 8g of the above-mentioned capsule particles containing inner core (60 and 80 mesh) in 100mL water, and mechanically stir at a speed of 300-400rpm to obtain a suspension, add the above-mentioned melamine resin prepolymer to the suspension, stir for 2min, add 0.4-0.5g citric acid, and react at 70°C for 10h to obtain sandwich structure 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 a nucleophilic addition reaction of carbonyl groups to generate intermediate product condensates.

[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 temperature of 4°C / min to 700°C for 3 h to obtain carbon-doped sandwich capsule particles (C@CMP);

[0056] Step 4: Preparation of intrinsic self-repairing high-performance shape memory anti-corrosion and microwave-absorbing coating

[0057] Take a 250mL three-necked flask, add a magnet and 4g of selenium powder, and connect it to a waste gas absorption bottle (1mol·L -1 NaOH solution, absorb H2Se), before the reaction, be sure to test the permeability and air tightness of the gas path; first add 20mL of water, then use a separatory funnel to slowly drop in 20mL of an aqueous solution containing 2g of NaBH4, after the addition is complete, react at 60°C for half an hour, treat with argon for 5min, add an aqueous solution containing 11g of 3-bromopropylamine hydrobromide (use 20mL of water), then add 25g of THF, and react at 60°C for 24h; after the reaction is completed, remove THF by rotary evaporation, extract the product with dichloromethane, continuously add NaOH solution, extract, filter, and then use anhydrous Na2SO4 to absorb moisture to obtain diselenamine.

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

[0059] When the thickness of CIP is 3.00 mm and the frequency is 16.5 GHz, the maximum reflection loss is -14.94 dB; the maximum reflection loss of C@CMP reaches -57.78 dB, and the corresponding thickness and frequency are 3.10 mm and 9.06 GHz, respectively. This shows that the sandwich structure of C@CMP effectively improves the wave absorption performance of particles.

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

Claims

1. A method for preparing a shape memory anti-corrosion and radar absorbing coating with intrinsic self-repairing properties, characterized in that: The method is: Step 1: preparing capsule particles containing an inner core: dissolving 5-15g of carbonyl iron (CIP) in 50-150mL of water, and mechanically stirring to obtain a CIP suspension; taking another container, dissolving 5-15g of an isocyanate monomer with a functionality of 2 or more in a mixed solvent consisting of 5-20g of an oily solvent and 5-20g of tetraethyl silicate or tetraethyl titanate at 50-100°C; mixing the CIP suspension with the above mixed solution, emulsifying for 20-50min, adding 0.3-1.0g of m-phenylenediamine, stirring for 3-10min, heating to 50-80°C, reacting for 10-50min, and then adding 0.5-2g of a diamine compound, and reacting for 5-16h; after the reaction is completed, sieving and filtering, and drying to obtain capsule particles containing an inner core; Step 2: Preparation of sandwich structure capsule particles Preparation of melamine resin prepolymer: 2-10g formaldehyde, 0.5-5g melamine, 5-15g H2O are mixed, the pH value is adjusted to 8-9, and the mixture is reacted in a constant temperature water bath at 50-80°C and 100-500rpm with magnetic stirring for 0.5-3h to obtain a prepolymer solution; in another container, 6-13g of the capsule particles containing the inner core are dissolved in 50-180mL water, and mechanically stirred at a speed of 300-600rpm to obtain a suspension, the melamine resin prepolymer is added to the suspension, stirred for 1-10min, 0.2-0.8g citric acid is added, and the mixture is reacted at 50-80°C for 5-12h to obtain sandwich structure capsule particles; 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 temperature of 3-10°C / min to 500-900°C for 2h-3h to obtain carbon-doped sandwich capsule particles (C@CMP); Step 4: Preparation of intrinsic self-repairing high-performance shape memory anti-corrosion and microwave-absorbing coating The resin matrix, toughening agent and diselenamine curing agent are mixed, and 2wt.%-8wt.% of C@CMP is added to obtain a mixture. The coating is prepared by spraying, spin coating, scraping, etc., and cured at 20-150°C for 2-20h to obtain a high-performance shape memory anti-corrosion and wave-absorbing coating with intrinsic self-repairing.

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

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

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

5. The method for preparing a shape memory anti-corrosion and radar absorbing coating with intrinsic self-repairing properties according to claim 1, characterized in that: In step 2, the pH regulator is triethanolamine or dipropylene glycolamine.

6. The method for preparing a shape memory anti-corrosion and radar absorbing coating with intrinsic self-repairing properties according to claim 1, characterized in that: In step 4, the resin matrix is ​​epoxy E44, E51, TDE85, etc., and the toughening agent is polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, etc.

7. The method for preparing a shape memory anti-corrosion and radar absorbing coating with intrinsic self-repairing properties according to claim 1, characterized in that: In step 4, the preparation method of the diselenamine curing agent is as follows: take a 250mL three-necked flask, add a magnetic rod, 2-10g of selenium powder, connect a waste gas absorption bottle, first add 10-30mL of water, and then use a separatory funnel to slowly drip an aqueous solution containing 1-5g of NaBH4, after the addition is complete, react at 40-80°C for half an hour, treat with argon for 2-20min, add an aqueous solution containing 5-20g of 3-bromopropylamine hydrobromide, and then add 10-50g of THF, and react at 40-80°C for 20-40h; after the reaction is completed, remove THF by rotary evaporation, extract and dry the product to obtain diselenamine.

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