Waterproof cable with anti-oil and self-repairing and preparation method thereof

Abstract

The application discloses a waterproof cable with oil-proof and self-repairing functions and a preparation method thereof, and belongs to the technical field of wires and cables. The cable comprises a copper conductor, an ethylene-propylene rubber insulation layer, an aluminum-plastic composite tape shielding layer, a polyethylene waterproof layer and a sheath layer. The sheath layer is composed of PVC, a plasticizer, a heat stabilizer, a lubricant, a filler, a flame retardant, a compatibilizer, an antioxidant, a thermoplastic polyurethane elastomer, a self-repairing prepolymer and an ultraviolet absorber. Compared with the prior art, the waterproof cable provided by the application has excellent oil-proof performance and multiple-cycle self-repairing capability, significantly improves the long-term service reliability of the cable in harsh environments such as marine engineering, underground pipe networks and sewage treatment, and has important engineering application value.

Description

Technical Field

[0001] This invention relates to the field of wire and cable technology, and in particular to a waterproof cable with oil-proof and self-healing properties, and its preparation method. Background Technology

[0002] As the core carrier of electrical energy transmission, cables face prominent problems such as insulation aging, plasticizer migration and precipitation in the sheath layer, and difficulty in repairing mechanical damage in humid, corrosive, and dynamic service environments. To solve these problems, existing technologies mainly focus on waterproof structural design, corrosion-resistant material modification, and the introduction of self-healing functions. However, most solutions cannot simultaneously achieve both the oil-proof performance of the sheath layer and its self-healing ability after damage.

[0003] Patent CN121096728A discloses a highly elastic waterproof cable based on a blend of water-blocking powder and elastomer. It enhances interlayer bonding stability by blending sodium polyacrylate water-blocking powder with an elastomer and designing a gradient insulation structure. However, its sheath layer lacks self-healing functionality, and the plasticizer easily migrates, leading to surface oiling. Patent CN120554778A discloses a corrosion-resistant waterproof cable that uses modified PVC and thermoplastic polyurethane elastomer as the main raw materials to give the sheath layer corrosion resistance and flame retardant properties. However, it does not address self-healing functionality and cannot solve the performance degradation caused by scratches or fatigue cracks in the sheath layer.

[0004] Therefore, existing cable technology still faces a dilemma: it is difficult to simultaneously achieve oil resistance and self-healing capabilities. In particular, the sheath layer becomes sticky and hardened due to plasticizer migration during long-term use, and microcracks cannot heal themselves, severely limiting the cable's service life in harsh environments. There is an urgent need to develop a waterproof cable and its manufacturing method that can effectively inhibit plasticizer exudation and achieve multiple cycles of self-healing. Summary of the Invention

[0005] In view of the shortcomings of the prior art, the present invention aims to provide a waterproof cable with oil resistance and self-healing properties, and a method for preparing the same.

[0006] To achieve the above-mentioned objectives, the present invention adopts the following technical solution: A waterproof cable with oil-proof and self-healing properties includes a copper conductor, an ethylene propylene rubber insulation layer outside the copper conductor, an aluminum-plastic composite tape shielding layer outside the insulation layer, a polyethylene waterproof layer outside the shielding layer, and a sheath layer outside the waterproof layer. The sheath layer comprises the following raw materials in parts by weight: 40-60 parts PVC, 3-8 parts plasticizer, 2-6 parts heat stabilizer, 0.8-2 parts lubricant, 9-17 parts filler, 4-8 parts flame retardant, 3-8 parts compatibilizer, 0.5-1.5 parts antioxidant, 20-30 parts thermoplastic polyurethane elastomer, 2-6 parts self-healing prepolymer, and 0.3-0.8 parts ultraviolet absorber.

[0007] The plasticizer is at least one of dioctyl terephthalate, diisononyl phthalate, dioctyl adipate, and propylene glycol adipate.

[0008] The heat stabilizer is at least one of calcium-zinc stabilizer, barium-zinc stabilizer, and organosilicon stabilizer.

[0009] The lubricant is at least one of calcium stearate, zinc stearate, glyceryl stearate, paraffin wax, and polyethylene wax.

[0010] The antioxidant is at least one of antioxidant 1010, antioxidant 168, antioxidant 245 and antioxidant 1076.

[0011] The filler is at least one of silicon dioxide and calcium carbonate.

[0012] The compatibilizer is at least one of chlorinated polyethylene, EVA-g-MAH, or PE-g-MAH.

[0013] The flame retardant is at least one of ammonium polyphosphate, bisphenol A diphenyl phosphate, magnesium hydroxide, aluminum hydroxide, zinc hydroxide, and triisopropylphenyl phosphate.

[0014] The ultraviolet absorber is at least one of UV-531, UV-234, and UV-328.

[0015] The method for preparing the waterproof cable with oil resistance and self-healing properties is as follows: Step 1: Use a twin-screw extruder to evenly coat the copper conductor with ethylene propylene rubber to form an insulating layer. Then, use a precision wrapping machine to spirally wrap aluminum-plastic composite tape around the outside of the insulating layer in an overlapping manner to form a shielding layer. Finally, use a cold-feed extrusion process to tightly wrap polyethylene material around the outside of the shielding layer to form a waterproof layer. Step 2: Weigh PVC, plasticizer, heat stabilizer, lubricant, filler, flame retardant, compatibilizer, and antioxidant, and place them in a high-speed mixer. Stir at 130-145℃ for 5-10 minutes. Then add thermoplastic polyurethane elastomer, self-healing prepolymer, and UV absorber, and continue mixing for 2-10 minutes until homogeneous. Feed the mixture into a single-screw extruder with a length-to-diameter ratio of 25-30:1 and a compression ratio of 2-4. Melt and extrude the mixture at a barrel temperature of 170-190℃, and directly extrude it onto the outside of the waterproof layer to form a sheath layer. After cooling, a waterproof cable with oil-proof and self-healing functions is obtained.

[0016] The preparation method of the self-healing prepolymer is as follows, in parts by weight: S1. Under nitrogen protection, 8-12 parts of a bis-primary amine compound and 15-20 parts of glycidyl acrylate are added to 80-150 parts of anhydrous tetrahydrofuran, and 0.1-0.5 parts of tetrabutylammonium bromide are added. The mixture is stirred at 50-70°C for 5-10 hours. After the reaction is completed, the mixture is rotary evaporated at a vacuum of -0.07 to -0.09 MPa and 40-60°C for 30-60 minutes to obtain the pretreated product. S2. Add 80-120 parts of terminal mercapto polydimethylsiloxane, 25-40 parts of the pretreated material obtained in step S1, and 4-7 parts of (3-mercaptopropyl)methyldimethoxysilane to 200-300 parts of anhydrous tetrahydrofuran, add 0.8-1.5 parts of photoinitiator, and react under nitrogen protection with ultraviolet light and stirring for 5-10 hours. After the reaction is completed, the self-healing prepolymer is obtained by rotary evaporation at a vacuum of -0.07~-0.09 MPa and 40-60℃ for 50-100 minutes.

[0017] The bis-primary amino compound is at least one of cystamine, 3,3'-dithiodipropylamine, 4,4'-diaminodiphenyl disulfide, bis(2-aminophenyl)disulfide, and selenocystamine.

[0018] Preferably, the bis-primary amino compound is composed of 4,4'-diaminodiphenyl disulfide and cystamine in a mass ratio of 0.5-2:0.5-2.

[0019] More preferably, the bis-primary amino compound is composed of 4,4'-diaminodiphenyl disulfide, cystamine, and selenocystamine in a mass ratio of 1-3:1-3:0.5-2.

[0020] This invention reveals that among numerous self-healing materials containing disulfide bonds, molecular structure significantly impacts repair efficiency. Ortho-aromatic disulfides suffer from significant steric hindrance, hindering effective disulfide bond exchange; while aliphatic segments, though flexible, lack sufficient thermal stability. Therefore, this invention utilizes para-aromatic disulfides to construct a regular, rigid framework, ensuring optimal orbital overlap of dynamic bonds, reducing the exchange energy barrier, and simultaneously leveraging the thermal stability of aromatic rings to maintain network integrity, thereby achieving more robust mechanical recovery.

[0021] In the experiments of this invention, it was found that a single type of disulfide bond is insufficient to simultaneously ensure network stability and chain segment mobility. Therefore, aromatic disulfides and aliphatic disulfides were compounded in a specific ratio to form a dual dynamic network that combines rigidity and flexibility. The rigid framework provides structural support at high temperatures, while the flexible segments promote molecular chain diffusion and bond exchange synergy. Together, they reduce the activation energy of dynamic exchange, broaden the effective repair temperature window, and enable the cable sheath to maintain excellent self-healing performance even after multiple cycles.

[0022] To further enhance the repair rate at low temperatures, this invention introduces selenocysteine ​​containing diselenobonds. The diselenobond bond energy is lower than that of the disulfide bond, preferentially undergoing rapid dynamic exchange at lower temperatures to achieve initial rapid healing of microcracks; while the disulfide bond takes over for deeper structural reinforcement under higher temperatures or sustained stress. This hierarchical dynamic response mechanism enables a simultaneous increase in repair rate and repair depth, ultimately achieving a more efficient self-healing effect.

[0023] Compared with the prior art, the present invention has the following beneficial technical effects: 1) This invention uses para-aromatic bis-primary amine disulfides to construct a regular rigid framework, which reduces the steric hindrance and activation energy barrier of dynamic disulfide bond exchange, and significantly improves the self-healing efficiency and structural stability of the sheath layer in multiple cycles.

[0024] 2) This invention combines aromatic and aliphatic bis-primary amino disulfides to form a dual dynamic network that combines rigidity and flexibility. The rigid framework ensures network integrity, while the flexible segments promote molecular diffusion and synergy, effectively broadening the repair temperature window. 3) This invention further introduces diselenyl bonds from selenocysteine, utilizing their lower bond energy than disulfide bonds to construct a hierarchical dynamic network. At low temperatures, selenium bonds rapidly heal microcracks, while at high temperatures, disulfide bonds reinforce and strengthen the network, achieving efficient hierarchical self-repair. Detailed Implementation

[0025] The present invention will be further described below with reference to specific embodiments, so that those skilled in the art can better understand and implement the present invention, but the embodiments are not intended to limit the present invention.

[0026] The specific details of the raw materials used in the embodiments and comparative examples of this invention are as follows: Ethylene propylene rubber: Grade: Keltan 2470, purchased from Lanxess, Germany.

[0027] Copper conductor: T2 copper rod with a diameter of 2.5mm and a purity of ≥99.95% is used, which conforms to GB / T 3953-2024 standard.

[0028] Aluminum-plastic composite tape: The tape has a total thickness of 0.15mm, including an aluminum foil layer of 0.05mm and a polyethylene adhesive layer of 0.10mm. The grade is 425 and it was purchased from 3M in the United States.

[0029] Polyethylene material: with a melt flow index of 2.0 g / 10 min (190℃ / 2.16 kg) and a density of 0.922 g / cm³. 3 The LDPE, grade Q281, was purchased from Shanghai Petrochemical.

[0030] PVC: SG-5 type suspension polyvinyl chloride resin with a polymerization degree of 1000±50 and a K value of 65 is used.

[0031] Propylene glycol adipate polyester: A polymeric plasticizer with a number average molecular weight of 2500, a hydroxyl value of 45±5 mgKOH / g, and an acid value of ≤1.0 mgKOH / g is used.

[0032] Calcium-zinc stabilizer: A powdered compound calcium-zinc heat stabilizer with a calcium content of 3.5% and a zinc content of 1.2% is used.

[0033] Polyethylene wax: High-density polyethylene wax with a number average molecular weight of 3000 and a melting point of 105℃ is used.

[0034] Hydrophobic nano-silica: using a specific surface area of ​​200m² 2 / g of fumed silica with an average particle size of 12nm and a hydrophobicity value ≥45, grade: HDK H20, purchased from Wacker Chemie, Germany.

[0035] Calcium carbonate: Heavy calcium carbonate with a particle size D50=10μm, whiteness ≥95%, and 1250 mesh is used.

[0036] Chlorinated polyethylene: The chlorine content is 35%, the Mooney viscosity ML(1+4) 121℃ is 55, the grade is CPE 135A, and it was purchased from Yaxing in Weifang, Shandong.

[0037] PE-g-MAH: Maleic anhydride-grafted polyethylene with a grafting rate of 1.2% and a melt index of 2.5 g / 10 min (190℃ / 2.16 kg), brand name Fusabond E100, purchased from DuPont, USA.

[0038] Thiol-terminated polydimethylsiloxane: The number-average molecular weight Mn=500 and thiol content 3.6mmol / g of the end-thiol polydimethylsiloxane were used.

[0039] Cystamine: CAS No. 51-85-4, purity ≥98%.

[0040] 3,3'-Dithiodipropylamine: CAS No. 463-22-9, purity ≥95%.

[0041] 4,4'-Diaminodiphenyl disulfide: CAS No. 722-27-0, purity ≥97%.

[0042] Bis(2-aminophenyl)disulfide: CAS No. 1141-88-4, purity ≥97%.

[0043] Selenocystamine: CAS No. 2697-61-2, purity ≥90%.

[0044] In the embodiments and comparative examples of this invention, all raw materials are commercially available products.

[0045] Example 1

[0046] A method for preparing a waterproof cable with oil-resistant and self-healing properties is as follows, in parts by weight: Step 1: Use a twin-screw extruder to evenly coat the copper conductor with ethylene propylene rubber to form an insulating layer. Then, use a precision wrapping machine to spirally wrap aluminum-plastic composite tape around the outside of the insulating layer in an overlapping manner to form a shielding layer. Finally, use a cold-feed extrusion process to tightly wrap polyethylene material around the outside of the shielding layer to form a waterproof layer. Step 2: Weigh 48 parts PVC, 5 parts propylene glycol adipate polyester, 4 parts calcium zinc stabilizer, 1.2 parts polyethylene wax, 3 parts hydrophobic nano silica, 10 parts calcium carbonate, 6 parts triisopropylphenyl phosphate, 3.5 parts chlorinated polyethylene, 1.5 parts PE-g-MAH, and 1 part antioxidant 1010, and place them in a high-speed mixer and stir at 138°C for 7 minutes; then add 25 parts thermoplastic polyurethane elastomer, 4 parts self-healing prepolymer, and 0.5 parts ultraviolet absorber UV-531, and continue mixing for 4 minutes until uniform; feed the mixture into a single-screw extruder with a length-to-diameter ratio of 28:1 and a compression ratio of 3, melt extrude at a barrel temperature of 183°C, and directly extrude it onto the outside of the waterproof layer to form a sheath layer. After cooling, a waterproof cable with oil-proof and self-healing functions is obtained.

[0047] The preparation method of the self-healing prepolymer is as follows, in parts by weight: S1. Under nitrogen protection, 10 parts of a bis-primary amine compound and 17 parts of glycidyl acrylate were added to 120 parts of anhydrous tetrahydrofuran, and 0.3 parts of tetrabutylammonium bromide were added. The mixture was stirred at 60°C for 8 hours. After the reaction was completed, the mixture was rotary evaporated at 50°C under a vacuum of -0.08 MPa for 50 minutes to obtain the pretreated product. S2. 100 parts of terminal mercapto polydimethylsiloxane, 33 parts of the pretreated material obtained in step S1, and 5.5 parts of (3-mercaptopropyl)methyldimethoxysilane were added to 250 parts of anhydrous tetrahydrofuran, and 1.2 parts of photoinitiator Irgacure819 were added. The mixture was irradiated with 365 nm ultraviolet light and stirred for 8 hours under nitrogen protection. After the reaction was completed, the self-healing prepolymer was obtained by rotary evaporation at -0.08 MPa and 50°C for 80 minutes.

[0048] The bis-primary amino compound is cystamine.

[0049] Example 2

[0050] The preparation method of a waterproof cable with oil resistance and self-healing properties is basically the same as that in Example 1, except that the bis-primary amine compound is 3,3'-dithiodipropylamine.

[0051] Example 3

[0052] The preparation method of a waterproof cable with oil resistance and self-healing properties is basically the same as that in Example 1, except that the bis-primary amine compound is 4,4'-diaminodiphenyl disulfide.

[0053] Example 4

[0054] The preparation method of a waterproof cable with oil-proof and self-healing properties is basically the same as that in Example 1, except that the bis(2-aminophenyl)disulfide is used.

[0055] Example 5

[0056] The preparation method of a waterproof cable with oil resistance and self-healing is basically the same as that in Example 1, except that the bis-primary amine compound is composed of 4,4'-diaminodiphenyl disulfide and cystamine in a mass ratio of 1:1.

[0057] Example 6

[0058] The preparation method of a waterproof cable with oil resistance and self-healing is basically the same as that in Example 1, except that the bis-primary amine compound is composed of 3,3'-dithiodipropylamine and cystamine in a mass ratio of 1:1.

[0059] Example 7

[0060] The preparation method of a waterproof cable with oil resistance and self-healing is basically the same as that in Example 1, except that the bis-primary amine compound is composed of 4,4'-diaminodiphenyl disulfide, cystamine and selenocystamine in a mass ratio of 2:2:1.

[0061] Comparative Example 1 The preparation method of a waterproof cable with oil resistance and self-healing properties is basically the same as that in Example 1, except that the self-healing prepolymer is not added.

[0062] Test Example 1 Multiple cycles of self-healing durability testing: Rectangular specimens with a length of 150 mm, a width of 10 mm, and a thickness equal to the original sheath thickness were cut from the cable sheath layers obtained in each embodiment and comparative example. A penetrating scratch with a depth of 30% of the specimen thickness was made perpendicular to the length direction in the middle of the specimen using a sharp blade. The specimens were then placed in a 60℃ constant temperature oven for 24 hours for repair, and then cooled to room temperature. Tensile testing was performed on the repaired area using an electronic universal testing machine at a tensile rate of 50 mm / min, according to GB / T 1040.3-2006 "Determination of Tensile Properties of Plastics Part 3: Test Conditions for Films and Sheets". The first repair efficiency was calculated. Subsequently, a scratch of the same depth was made again at the original scratch location on the same specimen, and the above repair-test process was repeated three times. The repair efficiency for the first, second, and third cycles was recorded. The ratio of the third repair efficiency to the first repair efficiency was used as the cycle durability retention rate. Three parallel specimens were tested for each embodiment, and the average value was taken. The results are shown in Table 1.

[0063] Table 1 Example 1 68.5 55.2 42.8 62.5 Example 2 72.1 60.3 48.5 67.3 Example 3 75.8 63.5 52.2 68.9 Example 4 45.3 32.8 22.4 49.4 Example 5 76.5 68.4 58.6 76.6 Example 6 70.2 58.5 45.8 65.2 Example 7 88.6 84.2 79.5 89.7 Comparative Example 1 4.1 3.2 2.1 - Test Example 2 Low-temperature rapid self-healing performance test: Rectangular specimens with a length of 50 mm and a width of 10 mm were cut from the cable sheath layers obtained in each embodiment and comparative example. Microhardness testers were used to create micron-level indentation cracks with a depth of 20 ± 5 μm on the specimen surface under a load of 500 g. The specimens were then placed in a 40℃ constant temperature oven for 12 hours for repair, and then cooled to room temperature. The crack length was observed and measured using an optical microscope at 200x magnification. The crack healing rate was calculated as (crack length before repair - crack length after repair) / crack length before repair × 100%. The average value of three parallel specimens was taken. The relevant test data are summarized in Table 2.

[0064] Table 2 Example 1 48.3 Example 2 53.2 Example 3 56.8 Example 4 25.1 Example 5 65.6 Example 6 51.9 Example 7 73.7 Comparative Example 1 1.5 In Examples 1-4, the symmetrical rigid framework of 4,4'-diaminodiphenyl disulfide used in Example 3 allows the dynamic disulfide bonds to be in a regular molecular conformation, and the para-aromatic framework allows the dynamic disulfide bonds to be in a more favorable orientation of the molecular chain segment, reducing the steric hindrance and energy barrier during bond exchange. At the same time, the thermal stability of the aromatic ring is better than that of the aliphatic chain segment, and it can maintain the integrity of the network structure at the repair temperature, thereby making the recovery of mechanical properties more complete.

[0065] Example 5 combines aromatic and aliphatic disulfides. The molecular design, combining rigidity and flexibility, allows the prepolymer backbone to possess both a rigid framework and flexible segments. The rigid structure provides the network with high-temperature stability and structural integrity, while the flexible segments promote molecular chain movement and diffusion contact of dynamic disulfide bonds. The two work synergistically to reduce the activation energy of dynamic exchange and broaden the effective repair temperature window. Therefore, the repair efficiency and cycle durability of the compound system are superior to those of the single component. Example 7 further introduces Se-Se bonds containing selenocysteine. Utilizing the lower bond energy of selenocysteine ​​bonds, a hierarchical dynamic covalent network is constructed. At lower temperatures, Se-Se bonds preferentially undergo rapid dynamic exchange, achieving initial rapid healing of microcracks. Meanwhile, SS bonds take over for deep structural reinforcement under higher temperatures or continuous stress. The hierarchical response mechanism of the two dynamic bonds synergistically enhances the repair rate and repair depth, thereby achieving a superior self-healing effect.

Claims

1. A waterproof cable with oil-proof and self-healing properties, characterized in that, It includes a copper conductor, an ethylene propylene rubber insulation layer outside the copper conductor, an aluminum-plastic composite tape shielding layer outside the insulation layer, a polyethylene waterproof layer outside the shielding layer, and a sheath layer outside the waterproof layer. The sheath layer comprises the following raw materials in parts by weight: 40-60 parts PVC, 3-8 parts plasticizer, 2-6 parts heat stabilizer, 0.8-2 parts lubricant, 9-17 parts filler, 4-8 parts flame retardant, 3-8 parts compatibilizer, 0.5-1.5 parts antioxidant, 20-30 parts thermoplastic polyurethane elastomer, 2-6 parts self-healing prepolymer, and 0.3-0.8 parts ultraviolet absorber.

2. The waterproof cable with oil-proof and self-healing properties as described in claim 1, characterized in that, The plasticizer is at least one of dioctyl terephthalate, diisononyl phthalate, dioctyl adipate, and propylene glycol adipate. The heat stabilizer is at least one of calcium-zinc stabilizer, barium-zinc stabilizer, and organosilicon stabilizer.

3. The waterproof cable with oil-proof and self-healing properties as described in claim 1, characterized in that, The lubricant is at least one of calcium stearate, zinc stearate, glyceryl stearate, paraffin wax, and polyethylene wax; The antioxidant is at least one of antioxidant 1010, antioxidant 168, antioxidant 245 and antioxidant 1076.

4. The waterproof cable with oil-proof and self-healing properties as described in claim 1, characterized in that, The filler is at least one of silicon dioxide and calcium carbonate; The compatibilizer is at least one of chlorinated polyethylene, EVA-g-MAH, or PE-g-MAH.

5. The waterproof cable with oil-proof and self-healing properties as described in claim 1, characterized in that, The flame retardant is at least one of ammonium polyphosphate, bisphenol A bis(diphenyl) phosphate, magnesium hydroxide, aluminum hydroxide, zinc hydroxide, and triisopropylphenyl phosphate. The ultraviolet absorber is at least one of UV-531, UV-234, and UV-328.

6. A method for preparing a waterproof cable with oil-resistant and self-healing properties as described in any one of claims 1-5, characterized in that, The method is as follows: Step 1: Use a twin-screw extruder to evenly coat the copper conductor with ethylene propylene rubber to form an insulating layer. Then, use a precision wrapping machine to spirally wrap aluminum-plastic composite tape around the outside of the insulating layer in an overlapping manner to form a shielding layer. Finally, use a cold-feed extrusion process to tightly wrap polyethylene material around the outside of the shielding layer to form a waterproof layer. Step 2: Weigh PVC, plasticizer, heat stabilizer, lubricant, filler, flame retardant, compatibilizer, and antioxidant, and place them in a high-speed mixer. Stir at 130-145℃ for 5-10 minutes. Then add thermoplastic polyurethane elastomer, self-healing prepolymer, and UV absorber, and continue mixing for 2-10 minutes until homogeneous. Feed the mixture into a single-screw extruder with a length-to-diameter ratio of 25-30:1 and a compression ratio of 2-4. Melt and extrude the mixture at a barrel temperature of 170-190℃, and directly extrude it onto the outside of the waterproof layer to form a sheath layer. After cooling, a waterproof cable with oil-proof and self-healing functions is obtained.

7. The method as described in claim 6, characterized in that, The preparation method of the self-healing prepolymer is as follows, in parts by weight: S1. Under nitrogen protection, 8-12 parts of a bis-primary amine compound and 15-20 parts of glycidyl acrylate are added to 80-150 parts of anhydrous tetrahydrofuran, and 0.1-0.5 parts of tetrabutylammonium bromide are added. The mixture is stirred at 50-70°C for 5-10 hours. After the reaction is completed, the mixture is rotary evaporated at a vacuum of -0.07 to -0.09 MPa and 40-60°C for 30-60 minutes to obtain the pretreated product. S2. Add 80-120 parts of terminal mercapto polydimethylsiloxane, 25-40 parts of the pretreated material obtained in step S1, and 4-7 parts of (3-mercaptopropyl)methyldimethoxysilane to 200-300 parts of anhydrous tetrahydrofuran, add 0.8-1.5 parts of photoinitiator, and react under nitrogen protection with ultraviolet light and stirring for 5-10 hours. After the reaction is completed, the self-healing prepolymer is obtained by rotary evaporation at a vacuum of -0.07~-0.09 MPa and 40-60℃ for 50-100 minutes.

8. The method as described in claim 7, characterized in that, The bis-primary amino compound is at least one of cystamine, 3,3'-dithiodipropylamine, 4,4'-diaminodiphenyl disulfide, bis(2-aminophenyl)disulfide, and selenocystamine.

9. The method as described in claim 7, characterized in that, The bis-primary amino compound is composed of 4,4'-diaminodiphenyl disulfide and cystamine in a mass ratio of 0.5-2:0.5-2.

10. The method as described in claim 7, characterized in that, The bis-primary amino compound is composed of 4,4'-diaminodiphenyl disulfide, cystamine, and selenocystamine in a mass ratio of 1-3:1-3:0.5-2.