Self-repairing material doped with double-shell photosensitive microcapsule and preparation method of self-repairing material

Abstract

The invention belongs to the technical field of microcapsule self-repairing materials, and particularly relates to a self-repairing material doped with a double-shell photosensitive microcapsule and a preparation method of the self-repairing material. Comprising the following steps: firstly, preparing a water phase containing amphiphilic nano silicon dioxide; adding a first solvent and diisocyanate into the photosensitive core material, and stirring in a dark place to obtain an oil phase; adding the oil phase into the water phase, stirring, adding small molecular polyol, and carrying out polymerization reaction to obtain the photosensitive microcapsule; then taking mixed tetraethoxysilane and methyltriethoxysilane, hydrolyzing under the action of a second solvent and a catalyst to obtain hydrolysate, adding the photosensitive microcapsule into the hydrolysate, and stirring to obtain a double-shell photosensitive microcapsule; and adding the double-shell photosensitive microcapsule into an epoxy resin base material, pouring and curing to obtain the self-repairing material doped with the double-shell photosensitive microcapsule. According to the invention, efficient repair of microscopic damage in the epoxy resin composite material is realized, and the service life of the epoxy resin composite material is effectively prolonged.

Description

Technical Field

[0001] The present invention belongs to the technical field of microcapsule self - healing materials, and particularly relates to a self - healing material doped with double - shell photosensitive microcapsules and a preparation method thereof. Background Art

[0002] Epoxy resin has been widely used in the fields of electronics, aerospace, construction, etc. due to its excellent insulation, chemical stability and mechanical properties. However, its inherent brittleness causes micro - cracks, scratches and other damages to easily occur on the material surface. These microscopic defects are difficult to detect and may gradually expand into macroscopic cracks, leading to a decline in insulation performance or even structural failure, seriously threatening the safety and service life of equipment. To solve this problem, the self - healing material technology has emerged, and the microcapsule method has become a research hotspot due to its simple operation and high repair efficiency.

[0003] The existing preparation methods of self - healing epoxy resin materials are mainly based on single - shell microcapsule technology. The principle is to coat the repair agent in the microcapsules and disperse them in the matrix. When the material is damaged, the microcapsules rupture to release the repair agent, and the damage is repaired through chemical reactions or physical filling. However, the following key problems exist in the practical application of this technology: 1. Insufficient stability of the triggering mechanism: Existing technologies mostly rely on mechanical stress to trigger the rupture of microcapsules. However, in practical applications, the randomness of the damage degree and stress distribution often leads to insufficient release or premature leakage of the repair agent. In addition, some studies use thermal triggering or chemical triggering mechanisms, but they are significantly affected by environmental temperature and humidity fluctuations, and the repair effect is difficult to be stably controlled.

[0004] 2. Defects in the mechanical strength and dispersibility of microcapsules: The shell materials of single - shell microcapsules (such as polyurea, polyurethane) have limited mechanical strength and are difficult to withstand the shear stress during material processing or service, and are prone to premature rupture during the mixing or curing stage. At the same time, the interfacial compatibility between the microcapsules and the epoxy resin matrix is poor, and agglomeration is easy to occur, resulting in uneven dispersion, forming stress concentration points and weakening the overall performance of the material.

[0005] 3. Core material stability and functional singularity: Existing repair core materials (such as epoxy monomers, curing agents) are easily affected by environmental factors such as light and oxygen, resulting in pre - curing or degradation, and the repair efficiency decreases after long - term storage. In addition, traditional core materials can only achieve a single repair function and lack the ability to synergistically repair complex damages (such as electro - mechanical coupling damages).

[0006] 4. Insufficient light responsiveness: Although the light - triggering mechanism has the advantages of precision and controllability, the existing photosensitive microcapsules have weak light - shielding ability, and the core material is easily interfered by external light in the undamaged state, resulting in unexpected curing and reducing the effective utilization rate of the repair agent.

[0007] In recent years, in response to the above problems, research has attempted to optimize through shell modification (such as introducing nanoparticle enhancement), double-layer encapsulation, or multifunctional core material design. However, there are still limitations such as complex processes, high costs, or insufficient compatibility.

[0008] In summary, the existing preparation methods of epoxy resin self-healing materials still have significant deficiencies in terms of trigger reliability, microcapsule durability, core material stability, and functional integration. There is an urgent need to develop a new microcapsule system with high mechanical strength, environmental stability, and precise light response to achieve efficient and controllable self-healing of epoxy resin materials. Summary of the Invention

[0009] In view of the above problems existing in the prior art, the present invention provides a self-healing material doped with double-shell photosensitive microcapsules and a preparation method thereof, which can improve the stability and damage repair ability of the microcapsules.

[0010] To achieve the above object, the technical solutions provided by the present invention are as follows: In a first aspect, the present application provides a preparation method of a self-healing material doped with double-shell photosensitive microcapsules, including the following steps: S1: Prepare an aqueous phase including amphiphilic nano-silica; add a first solvent and diisocyanate to a photosensitive core material containing aliphatic epoxy resin, stir in the dark to obtain an oil phase; add the oil phase to the aqueous phase, stir to obtain an emulsion; add a small molecule polyol to the emulsion, stir in the dark for a polymerization reaction, and after the reaction is completed, purify to obtain photosensitive microcapsules; S2: Take a mixture of tetraethoxysilane and methyltriethoxysilane with a mass ratio of (0.87~1.12):1 to obtain a siloxane mixture. The siloxane mixture is hydrolyzed in a second solvent and a catalyst to obtain a hydrolysis solution. Add the photosensitive microcapsules to the hydrolysis solution, stir, filter, wash, and dry to obtain double-shell photosensitive microcapsules; S3: Add the double-shell photosensitive microcapsules to an epoxy resin substrate, pour and cure to obtain the self-healing material doped with double-shell photosensitive microcapsules.

[0011] Optionally, the preparation of the aqueous phase includes: mixing deionized water, polyvinyl alcohol, and amphiphilic nano-SiO2 according to a mass ratio of 50:(4.5~5.5):(0.8~1.8), stirring and reacting at 70°C~90°C for 8~10 h to obtain the aqueous phase.

[0012] Optionally, the photosensitive core material includes the following components in parts by mass: 11.2~12.7 parts of aliphatic epoxy resin, 6 parts of dipropylene glycol diacrylate, and 1 part of 2-hydroxy-2-methylpropiophenone.

[0013] Optionally, the mass ratio of the photosensitive core material, the solvent and the diisocyanate is (2-5):(2.2-3.7):2.

[0014] Optionally, the polymerization reaction conditions are: 80-95 °C, stirring in the dark for 3-5 h.

[0015] Optionally, the diisocyanate is toluene-2,4-diisocyanate, and the small molecule polyol is 1,4-butanediol.

[0016] Optionally, the first solvent is ethyl phenylacetate.

[0017] Optionally, the second solvent is ethanol and / or water, and the catalyst is acetic acid.

[0018] Optionally, the mass ratio of the silicone mixture, the second solvent and the catalyst is (0.9-1.15):2:2.

[0019] Optionally, the preparation of the epoxy resin substrate in S3 includes the following method: mixing epoxy resin, 4-methylhexahydrophthalic anhydride, and 2,4,6-tris(dimethylaminomethyl)phenol in a mass ratio of (0.9-1.3):0.9:0.03, and magnetically stirring at 60-75 °C for 25-30 min.

[0020] Optionally, the addition amount of the double-shell photosensitive microcapsules is 5.5 wt%-6.5 wt% of the epoxy resin substrate.

[0021] Optionally, the addition amount of the double-shell photosensitive microcapsules is 6 wt% of the epoxy resin substrate.

[0022] Optionally, the curing process includes curing at 75-80 °C for 24-36 h and then curing at 110-120 °C for 24-36 h in sequence.

[0023] On the other hand, the present application also provides a self-healing material doped with double-shell photosensitive microcapsules, which is obtained by the preparation method described in the first aspect.

[0024] Compared with the prior art, the present application has at least the following beneficial effects: The self-healing material doped with double-shell photosensitive microcapsules prepared by the present invention realizes the efficient repair of internal microscopic damage in the epoxy resin composite material, effectively extends the service life of the epoxy resin composite material, and maintains the long-term safe operation of the equipment. At the same time, by introducing a double-shell structure with high mechanical strength and a silica outer layer with light shielding ability, not only the stability and durability of the microcapsules are improved, but also the long-term stability of the core material in the undamaged state and the rapid and effective response when damage occurs are ensured.

[0025] In the present invention, the silica shell is formed by the hydrolysis of siloxane obtained by mixing tetraethoxysilane and methyltriethoxysilane in a certain ratio. By introducing methyltriethoxysilane containing a hydrophobic group methyl, the surface energy of the silica shell can be reduced, and the influence of environmental moisture penetration on the core material can be reduced.

[0026] The addition of 2-hydroxy-2-methylpropiophenone to the oil phase of the present invention enables the core material in the self-healing material to be rapidly cured under ultraviolet light irradiation, and the repair can be completed within 2 minutes. The repair time of the material without the addition of 2-hydroxy-2-methylpropiophenone is more than twice that of the present application. Moreover, the hydroxyl group and methyl group in HMPP can form hydrogen bonds or van der Waals forces with the epoxy resin matrix, enhancing the interfacial bonding between the microcapsules and the matrix.

[0027] Ethyl phenylacetate EAC is added to the oil phase as an oily solvent, which can dissolve TDI and promote its polymerization reaction with BDO to form a polyurethane shell layer. Moreover, the addition of EAC reduces the viscosity of the core material and improves the dispersibility during the preparation of microcapsules. After adding EAC during the preparation of the oil phase, a stirring speed of only 180 - 200 r / min is required for uniform mixing. The low volatility and chemical inertness of EAC can protect the epoxy resin and photoinitiator in the core material from environmental influences, further enhancing the stability of the core material. Description of the Drawings

[0028] Figure 1 It is the scanning electron microscope image of the double-shell photosensitive microcapsules in Example 2 of the present application; Figure 2 It is the particle size distribution diagram of the double-shell photosensitive microcapsules in Example 2 of the present application; Figure 3 It is the electron microscope image of the self-healing process after the self-healing material in Example 2 of the present application is scratched; Figure 4 It is the scanning electron microscope image of the double-shell photosensitive microcapsules in Comparative Example 5 of the present application. Detailed Description of the Invention

[0029] The present invention will be further described in detail below with reference to the drawings: The experimental methods used in the embodiments of the present invention are all conventional methods unless otherwise specified.

[0030] The reagent materials used in this example can be purchased conventionally. For the quantitative experiments involved in the embodiments, at least three repeated experiments are set, and the results are averaged.

[0031] Source of Raw Materials: The polyvinyl alcohol, amphiphilic nano-SiO2 and nano-Al2O3 used in the embodiments of the present application are all purchased from Sinopharm Chemical Reagent Co., Ltd. Examples

[0032] This embodiment provides a preparation method of an epoxy resin scratch self - repairing material doped with double - shell photosensitive microcapsules, specifically as follows: S1. Preparation of photosensitive microcapsules Preparation of aqueous phase: Add 100 mL of deionized water to a 500 - mL opaque beaker, and successively add 10 g of polyvinyl alcohol (PVA) and 2 g of amphiphilic nano - SiO₂. Place the beaker in a water bath at 80 °C, turn on the mechanical stirring device, set the rotation speed to 320 r / min, and stir for 9 h to ensure that PVA and amphiphilic nano - SiO₂ are fully dissolved and dispersed to form a homogeneous and stable aqueous phase. During this process, PVA acts as an emulsifier, which helps to form an oil - in - water system in the subsequent step. Amphiphilic nano - SiO₂ not only has an emulsifying effect but also plays a special role in the microcapsule shell formed later.

[0033] Preparation of oil phase: Take a 250 - mL opaque beaker, first add 12 g of aliphatic epoxy resin ERL - 4221, 6 g of dipropylene glycol diacrylate (TPGDA), and 1 g of 2 - hydroxy - 2 - methylpropiophenone (HMPP), and stir at a speed of 250 r / min for 45 min. Then add 15 g of ethyl phenylacetate (EAC), 10 g of toluene - 2,4 - diisocyanate (TDI), and drop in 2 - 3 drops of oil - soluble fluorescent agent (in this embodiment, the oil - soluble fluorescent agent is added to facilitate the subsequent observation and research of microcapsules), adjust the rotation speed to 200 r / min, and stir in the dark for 30 min to mix evenly. Among them, ERL - 4221 serves as the core material matrix, TPGDA serves as the reactive diluent, and HMPP can cure the core material under ultraviolet light irradiation.

[0034] Slowly pour the prepared oil phase into the aqueous phase, while adjusting the mechanical stirring speed to 600 r / min, and stir for 2 h to obtain an emulsion. Then slowly add 4 g of 1,4 - butanediol (BDO), and stir in the dark at 80 °C at a speed of 700 r / min for 3 h. After the reaction, filter the product to remove excess water and impurities. Then wash the filter cake with deionized water, repeat the washing 3 - 5 times to ensure that the surface of the microcapsules is clean, and finally dry the washed microcapsules to obtain photosensitive microcapsules. In this step, BDO reacts with TDI to gradually form a polyurethane shell to encapsulate the core material. S2. Preparation of double-shell photosensitive microcapsules: Weigh 15 g of tetraethoxysilane (TEOS) and methyltriethoxysilane (MTEOS) accurately according to a mass ratio of 1:1, mix them to obtain a siloxane mixture, put it into a container, add 1 mL of acetic acid as a catalyst, and then add ethanol and water. Among them, the mass ratio of the siloxane mixture, ethanol, and water is strictly controlled at 1:2:2. Turn on the stirring device and stir for 24 h to obtain a hydrolyzate. Add the photosensitive microcapsules prepared in step 1 to the hydrolyzate, adjust the stirring speed to 200 r / min, and stir for 25 min. After the reaction is completed, separate the microcapsules coated with the siloxane mixture from the sol through a filtration device, and then perform a drying treatment to obtain double-shell photosensitive microcapsules. During the process, the siloxane mixture forms a second layer of shell on the surface of the microcapsules. This layer of silica shell has a light shielding ability and can effectively protect the core material from the external environment.

[0035] S3. Preparation of self-healing materials doped with double-shell photosensitive microcapsules: Mix E-51 epoxy resin, 4-methylhexahydrophthalic anhydride (MHHPA), and 2,4,6-tris(dimethylaminomethyl)phenol (DMP-30) according to a mass ratio of 1:0.9:0.03, stir magnetically at 60 °C for 30 min, add 9 wt% of double-shell photosensitive microcapsules, continue to stir until evenly mixed, evacuate to remove air bubbles in the composite material, pour it into a customized mold, and cure at 80 °C and 120 °C for 24 h and 24 h respectively to obtain self-healing materials doped with double-shell photosensitive microcapsules. Example

[0036] The difference from Example 1 is that the content of double-shell photosensitive microcapsules is 6 wt%. Example

[0037] The difference from Example 1 is that the content of double-shell photosensitive microcapsules is 3 wt%.

[0038] Comparative Example 1 The difference from Example 1 is that only a pure epoxy resin sample is prepared, and the content of double-shell photosensitive microcapsules is 0 wt%.

[0039] Comparative Example 2 The difference between this example and Example 1 is that amphiphilic nano-SiO2 is not added during the aqueous phase preparation process of the preparation of photosensitive microcapsules, and the rest of the preparation processes are the same as those in Example 1 to obtain microcapsules.

[0040] Comparative Example 3 The difference between this example and Example 1 is that PVA is not added during the aqueous phase preparation process of the preparation of photosensitive microcapsules, and the rest of the preparation processes are the same as those in Example 1 to obtain microcapsules.

[0041] Comparative Example 4 The difference between this comparative example and Example 1 is that amphiphilic nano-SiO₂ is adjusted to nano-Al₂O₃, and the rest of the preparation processes are the same as those in Example 1, and microcapsules are prepared.

[0042] Comparative Example 5 The difference between this comparative example and Example 1 is that methyltriethoxysilane is replaced with tetraethoxysilane (TEOS) of equal mass (methyltriethoxysilane is not included), and the rest of the preparation processes are the same as those in Example 1.

[0043] Performance test: I. Tensile property test is carried out on the self-healing materials prepared in the examples and comparative examples: The tensile property is tested by a servo-hydraulic material testing system at a speed of 8 mm / min. 10 specimens are tested for each sample, and their average value is calculated.

[0044] II. Electrical property test is carried out on the samples prepared in the examples and comparative examples: Relying on the power frequency breakdown experimental platform, 10 repeated tests are carried out on the samples of each doping concentration, the breakdown voltage of the composite material is statistically analyzed, and the influence of the microcapsule doping concentration on the electrical properties of the composite material is analyzed.

[0045] III. Self-healing property test is carried out on the self-healing materials prepared in the examples and comparative examples: Use a medical scalpel to scratch the surface of the self-healing material with the same depth and width to simulate the scratch damage in actual use. The damaged material is exposed to ultraviolet irradiation for 100 seconds to trigger the self-healing mechanism. Observe the damaged area through a scanning electron microscope to check whether the healing agent penetrates into the scratch and solidifies. The results are shown in Figure 3 . 10 repeated tests are carried out on the undamaged samples, damaged and unrepaired samples, and damaged and repaired samples of the self-healing material, and their AC breakdown field strengths are measured to evaluate the recovery degree of the electrical properties of the composite material after repair.

[0046] Table 1 Test results of the performance of the self-healing material Microcapsule content (wt%) Tensile strength (MPa) Average AC breakdown field strength (kV / mm) Average breakdown voltage before and after damage repair (kV / mm) Example 1 9 58.34 32.73 32.73、23.12、26.35 Example 2 6 63.23 36.56 36.56、29.24、32.56 Example 3 3 61.43 34.38 34.38、24.78、30.09 Comparative Example 1 0 (pure epoxy resin) 60.12 35.23 35.23、27.67、27.54 Comparative Example 2 6 58.85 35.56 35.56、19.57、19.72 Comparative Example 3 6 59.07 34.67 34.67、20.34、20.91 Comparative Example 4 6 58.55 35.89 35.89、19.07、19.75 Comparative Example 5 6 58.06 33.64 34.08、18.64、18.87 Figure 1 This is the scanning electron microscope image of the double-shell photosensitive microcapsules in Example 2 of this application. It can be clearly seen from the figure that the microcapsules are relatively uniformly distributed in the sample, the overall shape is approximately spherical, and the surface is relatively smooth. This morphological feature helps the microcapsules to be uniformly dispersed in the composite material and play their strengthening and repairing roles.

[0047] Figure 2This is the particle size distribution diagram of the double-shell photosensitive microcapsules in Example 2 of this application. It can be seen that the diameter range of the double-shell photosensitive microcapsules in this example is mainly in the interval of 100 - 160 μm, and shows a relatively uniform distribution trend within this interval, with an average particle size of 130.53 μm. A suitable particle size distribution is crucial for the performance of microcapsules in composite materials, as it affects the interaction between the microcapsules and the matrix and the overall properties of the material.

[0048] The variation of the tensile strength of the self-healing material with the doping concentration of microcapsules is shown in Table 1. The tensile strength values are the average of 10 measurements. The tensile strength of the pure epoxy resin with 0 wt% microcapsule addition in Comparative Example 1 is 60.12 MPa. The results show that as the microcapsule content increases from 0 wt% to 9 wt%, the tensile strength of the epoxy resin composite first increases to 63.23 MPa (Example 2) and then decreases to 58.34 MPa (Example 1). Compared with pure epoxy resin, the tensile strength of the composite material initially increases, and the addition of double-shell photosensitive microcapsules significantly improves the initial tensile strength of the composite material. This is because the microcapsules with a double-shell structure have higher mechanical strength compared to the single-shell structure, and can more effectively disperse stress in the composite material, thereby improving the overall tensile performance of the material. This structural design makes the microcapsules less likely to break in the composite material, maintaining the integrity and functionality of the material. The decrease in the tensile strength of the composite material can be explained from two aspects. On the one hand, with the increase in the doping concentration of microcapsules, too many microcapsules may lead to more interface defects inside the composite material. These microcapsules can be regarded as "defects" on the cross-section of the composite material, because they may generate stress concentration points in the material, thus becoming potential fracture sources during the tensile process. On the other hand, the interface between the microcapsule shell and the composite material matrix is a weak link in the material performance. During the tensile process, these interface regions may become the paths for crack propagation, resulting in a decrease in the overall tensile performance of the material. However, the outer silica layer of the microcapsules in the present invention has a light shielding ability, which helps to protect the core material from the external environment and enhances the stability of the core material, thereby offsetting the adverse effects brought by the interface weakness to a certain extent. Nevertheless, too high a microcapsule addition amount may still lead to a decline in the performance of the composite material, indicating that it is necessary to balance the doping concentration of microcapsules in the design of composite materials to optimize the comprehensive performance of the material.

[0049] It can be found from the test results of the average AC breakdown field strength of the self-healing materials in Table 1 that the composite materials exhibit different breakdown voltage characteristics at different microcapsule doping ratios. Compared with the undoped pure epoxy resin, the average breakdown voltages of the composite materials doped with 3wt% and 6wt% microcapsules after damage repair increased by 9.26% and 18.23%, respectively. The addition of photosensitive microcapsules shortened the average free path of carriers, resulting in less energy obtained under the action of the electric field, thereby reducing the damage to the molecular structure of the matrix and improving the insulation ability of the material. However, when the doping ratio of microcapsules increased to 9wt%, the average breakdown voltage of the composite material after damage repair decreased by 4.32% instead. This may be because the high-concentration microcapsules are prone to aggregation, causing internal defects in the material and uneven distribution of the local electric field, which in turn affects the insulation effect of the composite material.

[0050] Figure 3 The SEM images of the self-healing process of the self-healing material after scratching in Example 2 of the present application are shown. Through Figure 3 it can be clearly seen the penetration and curing of the healing material in the microcapsules inside the scratch, intuitively proving the self-healing function of the self-healing material in the present application.

[0051] Table 1 shows the breakdown voltage conditions of the self-healing materials in the examples and comparative examples of the present application before damage, after damage, and after self-healing. The self-healing material in Example 2 of the present application has the best self-healing effect after damage, with a fast light response speed (it can be achieved under ultraviolet light irradiation for 100 s). The breakdown voltage of the repaired sample recovered to 89.06% of the undamaged sample, significantly improving the durability and reliability of the self-healing material.

[0052] Figure 4 The SEM image of the double-shell photosensitive microcapsule in Comparative Example 5 is shown. Compared with Figure 1 it, this microcapsule presents an approximate spherical shape, but the surface is relatively rough, with more protrusions and irregular textures. It shows that the surface uniformity of the silica outer layer obtained by hydrolyzing tetraethoxysilane alone is poor, and there is a lack of the shell layer. While the silica outer layer prepared by co-hydrolyzing tetraethoxysilane and methyltriethoxysilane has good shell layer uniformity, and the addition of methyl also improves the rigid support of the shell layer and is not easy to deform. The rough surface morphology will also affect the dispersion of the microcapsules in the composite material. Compared with the microcapsules with a smooth surface, it is more difficult to disperse uniformly in the matrix, affecting the self-healing effect.

Claims

1. A preparation method of a self-healing material doped with double-shell photosensitive microcapsules, characterized in that, It includes the following steps: S1: Prepare an aqueous phase containing amphiphilic nano-silica; add a first solvent and diisocyanate to a photosensitive core material containing an aliphatic epoxy resin, and stir in the dark to obtain an oil phase; add the oil phase to the aqueous phase and stir to obtain an emulsion; add a small molecule polyol to the emulsion, stir in the dark for a polymerization reaction, and after the reaction is completed, purify to obtain photosensitive microcapsules; S2: Take a mixture of tetraethoxysilane and methyltriethoxysilane with a mass ratio of (0.87~1.12):1 to obtain a siloxane mixture. The siloxane mixture is hydrolyzed with a second solvent and a catalyst to obtain a hydrolysis solution. Add the photosensitive microcapsules to the hydrolysis solution, stir, filter, wash, and dry to obtain double-shell photosensitive microcapsules; S3: Add the double-shell photosensitive microcapsules to an epoxy resin substrate, pour and cure to obtain the self-healing material doped with double-shell photosensitive microcapsules.

2. The preparation method of the self-healing material of the doped double-shell photosensitive microcapsules according to claim 1, characterized in that, The preparation of the aqueous phase includes: mixing deionized water, polyvinyl alcohol, and amphiphilic nano-SiO2 according to a mass ratio of 50:(4.5~5.5):(0.8~1.8), and stirring and reacting at 70°C to 90°C for 8 to 10 h to obtain the aqueous phase.

3. The preparation method of the self-healing material of the doped double-shell photosensitive microcapsules according to claim 1, wherein The photosensitive core material includes the following components in parts by mass: 11.2~12.7 parts of aliphatic epoxy resin, 6 parts of dipropylene glycol diacrylate, and 1 part of 2-hydroxy-2-methylpropiophenone.

4. The preparation method of the self-healing material of the doped double-shell photosensitive microcapsules according to claim 1, characterized in that, The mass dosage ratio of the photosensitive core material, solvent, and diisocyanate is (2~5):(2.2~3.7):

2.

5. The preparation method of the self-healing material of the doped double-shell photosensitive microcapsules according to claim 1, characterized in that, The polymerization reaction conditions are: 80~95°C, stirring in the dark for 3~5 h.

6. The preparation method of the self-healing material of the doped double-shell photosensitive microcapsules according to claim 1, wherein, The diisocyanate is toluene-2,4-diisocyanate, and the small molecule polyol is 1,4-butanediol.

7. The preparation method of the self-healing material of the doped double-shell photosensitive microcapsules according to claim 1, characterized in that, The second solvent is ethanol and / or water, and the catalyst is acetic acid.

8. The preparation method of the self-healing material of the doped double-shell photosensitive microcapsules according to claim 1, wherein The preparation of the epoxy resin substrate in S3 includes the following method: mix epoxy resin, 4-methylhexahydrophthalic anhydride, and 2,4,6-tris(dimethylaminomethyl)phenol according to a mass ratio of (0.9~1.3):0.9:0.03, and magnetically stir at 60~75°C for 25~30 min.

9. The preparation method of the self-healing material of the doped double-shell photosensitive microcapsules according to claim 1, characterized in that, The addition amount of the double-shell photosensitive microcapsules is 5.5wt%-6.5wt% of the epoxy resin substrate.

10. A self-healing material doped with double-shell photosensitive microcapsules, characterized in that, Obtained by the preparation method according to any one of claims 1-9.

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