Preparation method of self-repairing environment-friendly cable insulation material based on disulfide bond and DA reaction
A self-healing and environmentally friendly cable insulation material was prepared by grafting a reversible crosslinking agent with disulfide bonds and DA reaction with nano-silica. This solved the water treeing and electrical treeing defects of traditional crosslinked polyethylene materials, achieving multiple self-healing and recyclability, improving insulation performance and mechanical strength, and extending cable life.
Patent Information
- Application Number
- CN202511758578.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-27
- Publication Date
- 2026-03-17
AI Technical Summary
Traditional cross-linked polyethylene cable insulation materials are prone to water treeing and electrical treeing defects during use, leading to insulation breakdown. They are also difficult to recycle, affecting power grid safety and exacerbating environmental pollution.
An environmentally friendly cable insulation material with self-healing capabilities was prepared by using a reversible crosslinking agent based on disulfide bonds and DA reaction and a nano-silica grafting modification technique. Reversible crosslinking sites were introduced through disulfide bonds and DA reaction, and modified SiO2 particles were doped to enhance self-healing and recyclability.
It enables cable insulation materials to self-repair multiple times, improves insulation performance and mechanical strength, and the materials are recyclable, reducing environmental pollution and extending the service life of cables.
Smart Images
Figure CN121673597A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the research field of self-healing and environmental protection technology of insulation materials; specifically, it relates to a method for preparing a self-healing and environmentally friendly cable insulation material based on disulfide bonds and DA reaction. Background Technology
[0002] Cross-linked polyethylene (XLPE), with its excellent insulation properties, heat resistance, and mechanical strength, has long dominated the field of high-voltage cable insulation, providing core support for the stable operation of power transmission systems. However, in actual use, residual mechanical micro-defects from the manufacturing process, electric field concentration caused by long-term overvoltage, and environmental moisture infiltration can accelerate the evolution of insulation defects such as water trees and electrical trees. Water trees form microporous channels along the electric field in humid environments, while electrical trees continuously erode the insulation structure due to partial discharge. The long-term effect of both eventually leads to insulation breakdown, seriously threatening power grid safety. A prominent contradiction is that traditional XLPE, as a thermosetting material, is difficult to reshape once a cross-linked network is formed. It is not only non-recyclable, but also, due to its extremely high thermal degradation temperature (>400°C), becomes a persistent pollutant that is difficult for the environment to absorb, exacerbating resource waste and environmental pollution.
[0003] Although various self-healing systems exist to extend the lifespan of insulation materials, problems such as low self-healing efficiency, inability to recycle cross-linked polyethylene, and impact on matrix properties remain unresolved. Therefore, it is necessary to develop a cross-linked polyethylene composite insulation material with multiple self-healing capabilities and recyclability, fundamentally exploring methods to extend the service life of insulation materials. Summary of the Invention
[0004] The purpose of this invention is to provide a method for preparing a self-healing, environmentally friendly cable insulation material based on disulfide bonds and the DA reaction. The aim is to prepare a novel composite insulated power cable material with overall performance superior to traditional XLPE cables, further improving the cable's service life and insulation performance.
[0005] A method for preparing a self-healing, environmentally friendly cable insulation material based on disulfide bonds and DA reactions is achieved through the following steps:
[0006] I. Preparation of reversible crosslinking agent:
[0007] DFDL (2,2-dithiodiethanol) and IPDI (isophorone diisocyanate) were added to a three-necked flask purged with N2, followed by the addition of DMF (N,N-dimethylformamide) and DBTDL (dibutyltin dilaurate). The mixture was heated to 60°C and held for 2 hours. Next, hydroxyethyl methacrylate was added, and the mixture was heated to 75°C and held for 1 hour. Then, furfurylamine dissolved in DMF was added dropwise, and the mixture was heated to 75°C and held for 1 hour. Finally, BMI (N,N′-(4,4′-methylenediphenyl)dimaleimide) was added and the reaction was carried out for 24 hours. After washing and drying, a purified compound containing DA bonds and disulfide bonds was obtained, named the reversible crosslinking agent SS-DA, for later use.
[0008] II. Grafting modification of nano-silica surface:
[0009] Untreated SiO2 and acetone were added to an Erlenmeyer flask and magnetically stirred for 30 minutes to obtain solution A;
[0010] KH570 (γ-methacryloxypropyltrimethoxysilane), acetone and distilled water were mixed and magnetically stirred for 30 min to obtain solution B;
[0011] Solution A and solution B were mixed and magnetically stirred for 120 min, then ultrasonically oscillated for 30 min. After drying and grinding, KH570 grafted SiO2 particles were obtained.
[0012] III. Preparation of Self-Healing Environmentally Friendly Insulation Materials:
[0013] DCP (dicumyl peroxide) and SS-DA were dissolved in anhydrous ethanol, and then ball-milled LDPE (low-density polyethylene) was added. After stirring and mixing, the mixture was allowed to stand for 10 hours to obtain an LDPE mixture.
[0014] LDPE and antioxidant 1010 were added to a torque rheometer and melted until the torque stabilized. Then, LDPE mixture was added and melting continued for 2-4 minutes. KH570-grafted SiO2 particles were added and melting continued for 2 minutes to obtain the composite material.
[0015] The above-mentioned composite material was granulated, sampled by a flat vulcanizing machine, and then vacuum dried to obtain a novel cross-linked polyethylene, named a self-healing environmentally friendly cable insulation material based on disulfide bonds and DA reaction, denoted as XLPE-SS-DA-SiO2, thus completing the preparation method.
[0016] Furthermore, the total amount of DFDL and IPDI mentioned in step one is 20g, and their molar ratio is n-NCO / n-OH = 1.
[0017] Furthermore, in step one, the amounts of DMF and DBTDL used are 20 mL and 2 mL, respectively; the amount of hydroxyethyl methacrylate used is 10 mL.
[0018] Furthermore, regarding the furfurylamine dissolved in DMF in step one: 1.92 g of furfurylamine is dissolved in 10 mL of DMF; the amount of BMI used is 7.16 g.
[0019] Furthermore, the washing and drying described in step one: wash 2-3 times with anhydrous ethanol, and then dry at 60°C.
[0020] Furthermore, the particle size of the SiO2 in step two is 20 nm; the amounts of SiO2 and acetone used are 20 g and 50 ml, respectively.
[0021] Furthermore, in step two, the amounts of KH570, acetone, and distilled water used are 10 ml, 20 ml, and 50 ml, respectively.
[0022] Furthermore, the vacuum drying and grinding described in step two: drying in a vacuum drying oven at 60°C for 4 hours, followed by grinding for 2 hours.
[0023] Furthermore, the LDPE after ball milling described in step three: place the LDPE in a ball mill and ball mill it at a speed of 300 r / min for 2 hours.
[0024] Furthermore, the melting parameters in step three are a temperature of 110°C and a rotation speed of 50 r / min.
[0025] Furthermore, in step three, the amounts of DCP, SS-DA, and anhydrous ethanol used are 0.08g, 0.8g, and 6mL, respectively; the amount of LDPE used is 6.3g.
[0026] Furthermore, in step three, the amounts of LDPE and antioxidant 1010 are 33.7g and 0.12g, respectively; the amount of SiO2 particles grafted with KH570 is 0.4g.
[0027] Furthermore, in step three, the flat vulcanization sample preparation process involves setting the temperature to 110°C, placing the granulated composite material inside, starting heating, increasing the pressure by 5 MPa every 5 minutes after 15 minutes, and making a total sample preparation time of 30 minutes.
[0028] Furthermore, the vacuum drying process described in step three involves drying in a vacuum drying oven at 80°C.
[0029] Mechanism of the invention:
[0030] The reversible crosslinking agent prepared in this invention is a compound containing DA bonds and disulfide bonds, synthesized by utilizing the reaction characteristics of isocyanate groups and hydroxyl groups, with carbon-carbon double bonds at both ends, which can serve as crosslinking sites; and the disulfide bonds and DA reactive bonds contained therein can be rebonded at high temperature, making it a reversible compound.
[0031] The nano-silica prepared by the present invention with surface-grafted silane coupling agent is made by introducing silanol and a small amount of siloxane molecules on the surface of nano-silica. The grafted organic functional groups are well compatible with the polyethylene matrix and can react with water to give the material water tree self-healing ability.
[0032] This invention synthesizes a novel reversible crosslinking agent based on the reactivity of isocyanate groups and hydroxyl groups. This agent is then used as a crosslinking site for crosslinked polyethylene through a crosslinking reaction. Finally, nano-silica with a surface-grafted silane coupling agent is used as a blended inorganic material to form a composite structure of inorganic particles doped with crosslinked polyethylene. By synthesizing the reversible crosslinking agent and then using it as a crosslinking site for crosslinked polyethylene, a reversible crosslinked polymer is obtained. By grafting monomers and inorganic particles to regulate the grafting reaction, a silane coupling agent grafted with SiO2 inorganic particles is obtained. Through melt blending, a self-healing, environmentally friendly insulating material based on disulfide bonds and the DA reaction is obtained. The self-healing, mechanical, and dielectric properties of the composite material are controlled by the content of the reversible crosslinking agent.
[0033] The self-healing environmentally friendly cable insulation material prepared by this invention, based on disulfide bonds and DA reaction, introduces disulfide bonds and DA reaction bonds in the reversible crosslinking agent through a crosslinking reaction, making the material a self-healing environmentally friendly insulation material capable of self-repairing cracks, electrical trees, and water trees, as well as material recycling; and the nano-silica modified with silane coupling agent enables the material to consume internal moisture, promoting the self-repair of water trees.
[0034] Advantages of this invention:
[0035] (1) The novel reversible crosslinking agent serves as a crosslinking site, enabling the material to undergo fracture and recombination, i.e., multiple self-repair capabilities.
[0036] (2) The cross-linking sites contain disulfide bonds and DA reaction bonds, which makes the material recyclable multiple times.
[0037] (3) The silane coupling agent on the surface of modified SiO2 (i.e., SiO2 particles grafted with KH570) reacts with water to generate oligomers, which consume the water in the material. The organic polymer generated after the reaction can fill the micropores, thereby eliminating water treeing and increasing the self-healing ability of the material.
[0038] (4) The incorporation of modified SiO2 and the introduction of novel reversible crosslinking agents have improved the insulation and mechanical properties of the material.
[0039] (5) The self-healing environmentally friendly cable insulation material prepared by the present invention based on disulfide bond and DA reaction has better comprehensive performance than the new composite insulation power cable material of traditional XLPE cable, further improving the service life and insulation performance of the cable, and realizing the concept of environmental protection.
[0040] This invention is applicable to the preparation of self-healing environmentally friendly cable insulation materials based on disulfide bonds and DA reactions. Attached Figure Description
[0041] Figure 1 This is a schematic diagram of the reversible crosslinking agent in the examples;
[0042] Figure 2 This is a schematic diagram of self-healing breakdown in the embodiment;
[0043] Figure 3 This is a schematic diagram of the self-repair of mechanical damage in the embodiment;
[0044] Figure 4 This is a schematic diagram of the self-repair mechanism for aging tree branches in the embodiment;
[0045] Figure 5 This is a schematic diagram illustrating the self-healing principle in the embodiment.
[0046] Figure 6 The image shows a physical picture of the self-healing environmentally friendly cable insulation material prepared in the examples, based on disulfide bonds and DA reactions. Detailed Implementation
[0047] The technical solution of the present invention is not limited to the specific embodiments listed below, but also includes any combination of the specific embodiments.
[0048] Specific Implementation Method 1: This implementation method provides a method for preparing a self-healing and environmentally friendly cable insulation material based on disulfide bonds and DA reactions, which is achieved through the following steps:
[0049] I. Preparation of reversible crosslinking agent:
[0050] DFDL and IPDI were added to a three-necked flask purged with N2, followed by DMF and DBTDL. The mixture was heated to 60°C and held for 2 hours. Next, hydroxyethyl methacrylate was added, and the mixture was heated to 75°C and held for 1 hour. Then, furfurylamine dissolved in DMF was added dropwise, and the mixture was heated to 75°C and held for 1 hour. Finally, BMI was added and the mixture was reacted for 24 hours. After washing and drying, a purified compound containing DA bonds and disulfide bonds was obtained. This compound was named the reversible crosslinking agent and designated as SS-DA.
[0051] II. Grafting modification of nano-silica surface:
[0052] Untreated SiO2 and acetone were added to an Erlenmeyer flask and magnetically stirred for 30 minutes to obtain solution A;
[0053] KH570, acetone and distilled water were mixed and magnetically stirred for 30 minutes to obtain solution B;
[0054] Solution A and solution B were mixed and magnetically stirred for 120 min, then ultrasonically oscillated for 30 min. After drying and grinding, KH570 grafted SiO2 particles were obtained.
[0055] III. Preparation of Self-Healing Environmentally Friendly Insulation Materials:
[0056] DCP and SS-DA were dissolved in anhydrous ethanol, and then ball-milled LDPE was added. After stirring and mixing, the mixture was allowed to stand for 10 hours to obtain an LDPE mixture.
[0057] LDPE and antioxidant 1010 were added to a torque rheometer and melted until the torque stabilized. Then, LDPE mixture was added and melting continued for 2-4 minutes. KH570-grafted SiO2 particles were added and melting continued for 2 minutes to obtain the composite material.
[0058] The above-mentioned composite material was granulated, sampled by a flat vulcanizing machine, and then vacuum dried to obtain a novel cross-linked polyethylene, named a self-healing environmentally friendly cable insulation material based on disulfide bonds and DA reaction, denoted as XLPE-SS-DA-SiO2, thus completing the preparation method.
[0059] In step two of this embodiment, the ultrasonic oscillation treatment for 30 minutes is intended to allow the coupling agent to fully react with the nanoparticles.
[0060] In step three of this implementation method, the torque rheometer needs to be parameter-set and cleaned before use to eliminate errors caused by impurities. Torque rheometer parameter settings: Turn on the instrument switch and computer, set the temperature of zones one, two, and three of the torque rheometer to 110℃, adjust the speed to 50 r / min, and then establish a communication connection; start the heating system, and when the temperature stabilizes at 110℃±2℃, start the torque rheometer; weigh 40g of pure low-density polyethylene for cleaning the instrument, repeat the cleaning 2-3 times until there are no impurities in the head and no foreign objects in the screw, before proceeding with subsequent experiments.
[0061] Specific Implementation Method Two: This implementation method differs from Specific Implementation Method One in that the total amount of DFDL and IPDI mentioned in step one is 20g, and their molar ratio is n-NCO / n-OH = 1. Other steps and parameters are the same as in Specific Implementation Method One.
[0062] Specific Implementation Method 3: This implementation method differs from Specific Implementation Method 1 in that the amounts of DMF and DBTDL used in step one are 20 mL and 2 mL, respectively; the amount of hydroxyethyl methacrylate used is 10 mL. Other steps and parameters are the same as in Specific Implementation Method 1.
[0063] Specific Implementation Method Four: This implementation method differs from Specific Implementation Method One in that, in step one, the furfurylamine dissolved in DMF is: 1.92g of furfurylamine is dissolved in 10mL of DMF; the amount of BMI used is 7.16g. Other steps and parameters are the same as in Specific Implementation Method One.
[0064] Specific Implementation Method Five: This implementation method differs from Specific Implementation Method One in that the washing and drying in step one involves washing 2-3 times with anhydrous ethanol, followed by drying at 60°C. Other steps and parameters are the same as in Specific Implementation Method One.
[0065] Specific Implementation Method Six: This implementation method differs from Specific Implementation Method One in that the particle size of the SiO2 in step two is 20nm; the amounts of SiO2 and acetone used are 20g and 50ml, respectively. Other steps and parameters are the same as in Specific Implementation Method One.
[0066] Specific Implementation Method Seven: This implementation method differs from Specific Implementation Method One in that the amounts of KH570, acetone, and distilled water used in step two are 10 ml, 20 ml, and 50 ml, respectively. Other steps and parameters are the same as in Specific Implementation Method One.
[0067] Specific Implementation Method Eight: This implementation method differs from Specific Implementation Method One in that the vacuum drying and grinding in step two involves drying in a vacuum drying oven at 60°C for 4 hours, followed by grinding for 2 hours. Other steps and parameters are the same as in Specific Implementation Method One.
[0068] Specific Implementation Method Nine: This implementation method differs from Specific Implementation Method One in that, in step three, the LDPE after ball milling is placed in a ball mill and ball-milled at 300 r / min for 2 hours. Other steps and parameters are the same as in Specific Implementation Method One.
[0069] Specific Implementation Method Ten: This implementation method differs from Specific Implementation Method One in that the melting parameters in step three are a temperature of 110℃ and a rotation speed of 50 r / min. Other steps and parameters are the same as in Specific Implementation Method One.
[0070] Specific Implementation Method Eleven: This implementation method differs from Specific Implementation Method One in that the amounts of DCP, SS-DA, and anhydrous ethanol used in step three are 0.08g, 0.8g, and 6mL, respectively; the amount of LDPE used is 6.3g. Other steps and parameters are the same as in Specific Implementation Method One.
[0071] Specific Implementation Method Twelve: This implementation method differs from Specific Implementation Method One in that the amounts of LDPE and antioxidant 1010 used in step three are 33.7g and 0.12g, respectively; the amount of KH570-grafted SiO2 particles used is 0.4g. Other steps and parameters are the same as in Specific Implementation Method One.
[0072] Specific Implementation Method Thirteen: This implementation method differs from Specific Implementation Method One in that, in step three, the flat vulcanization sample preparation is performed as follows: the temperature is set to 110°C, the granulated composite material is placed in the sample, heating begins, and the pressure is increased by 5 MPa every 5 minutes after 15 minutes, with a total sample preparation time of 30 minutes. Other steps and parameters are the same as in Specific Implementation Method One.
[0073] In this embodiment, the purpose of pressurization is to fully shape the composite material after pelletizing, so that impurity gases can be fully discharged.
[0074] Specific Implementation Method Fourteen: This implementation method differs from Specific Implementation Method One in that the vacuum drying process in step three involves drying in a vacuum drying oven at 80°C. All other steps and parameters are the same as in Specific Implementation Method One.
[0075] In this embodiment, the purpose of vacuum drying is to reduce residual stress inside the material.
[0076] The beneficial effects of the present invention are verified through the following embodiments:
[0077] The following description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.
[0078] Example:
[0079] A method for preparing a self-healing, environmentally friendly cable insulation material based on disulfide bonds and DA reactions is achieved through the following steps:
[0080] I. Preparation of reversible crosslinking agent:
[0081] DFDL and IPDI were added to a three-necked flask purged with N2, followed by DMF and DBTDL. The mixture was heated to 60°C and held for 2 hours. Next, hydroxyethyl methacrylate was added, and the mixture was heated to 75°C and held for 1 hour. Then, furfurylamine dissolved in DMF was added dropwise, and the mixture was heated to 75°C and held for 1 hour. Finally, BMI was added and the mixture was reacted for 24 hours. After washing and drying, a purified compound containing DA bonds and disulfide bonds was obtained. This compound was named the reversible crosslinking agent and designated as SS-DA.
[0082] II. Grafting modification of nano-silica surface:
[0083] Untreated SiO2 and acetone were added to an Erlenmeyer flask and magnetically stirred for 30 minutes to obtain solution A;
[0084] KH570, acetone and distilled water were mixed and magnetically stirred for 30 minutes to obtain solution B;
[0085] Solution A and solution B were mixed and magnetically stirred for 120 min, then ultrasonically oscillated for 30 min. After drying and grinding, KH570 grafted SiO2 particles were obtained.
[0086] III. Preparation of Self-Healing Environmentally Friendly Insulation Materials:
[0087] DCP and SS-DA were dissolved in anhydrous ethanol, and then ball-milled LDPE was added. After stirring and mixing, the mixture was allowed to stand for 10 hours to obtain an LDPE mixture.
[0088] LDPE and antioxidant 1010 were added to a torque rheometer and melted until the torque stabilized. Then, LDPE mixture was added and melting continued for 3 minutes. KH570 grafted SiO2 particles were added and melting continued for 2 minutes to obtain the composite material.
[0089] The above-mentioned composite material was granulated, sampled by a flat vulcanizing machine, and then vacuum dried to obtain a novel cross-linked polyethylene, named a self-healing environmentally friendly cable insulation material based on disulfide bonds and DA reaction, denoted as XLPE-SS-DA-SiO2, thus completing the preparation method.
[0090] In step one of this embodiment, the total amount of DFDL and IPDI is 20g, and the molar ratio of the two is n-NCO / n-OH = 1.
[0091] In step one of this embodiment, the amounts of DMF and DBTDL used are 20 mL and 2 mL, respectively; the amount of hydroxyethyl methacrylate used is 10 mL.
[0092] In step one of this embodiment, the furfurylamine dissolved in DMF is as follows: 1.92g of furfurylamine is dissolved in 10mL of DMF; the amount of BMI used is 7.16g.
[0093] The washing and drying process described in step one of this embodiment involves washing three times with anhydrous ethanol and then drying at 60°C.
[0094] In step two of this embodiment, the particle size of SiO2 is 20nm; the amounts of SiO2 and acetone used are 20g and 50ml, respectively.
[0095] In step two of this embodiment, the amounts of KH570, acetone, and distilled water used are 10 ml, 20 ml, and 50 ml, respectively.
[0096] The vacuum drying and grinding described in step two of this embodiment are as follows: drying in a vacuum drying oven at 60°C for 4 hours, followed by grinding for 2 hours.
[0097] In step three of this embodiment, the LDPE after ball milling is placed in a ball mill and ball milled at a speed of 300 r / min for 2 hours.
[0098] In step three of this embodiment, the melting parameters are a temperature of 110°C and a rotation speed of 50 r / min.
[0099] In step three of this embodiment, the amounts of DCP, SS-DA, and anhydrous ethanol used are 0.08g, 0.8g, and 6mL, respectively; the amount of LDPE used is 6.3g.
[0100] In step three of this embodiment, the amounts of LDPE and antioxidant 1010 are 33.7g and 0.12g, respectively; the amount of SiO2 particles grafted with KH570 is 0.4g.
[0101] In step three of this embodiment, the flat vulcanization sample preparation process is as follows: the temperature is set to 110°C, the granulated composite material is placed in the sample, heating is started, and the pressure is increased by 5 MPa every 5 minutes after 15 minutes. The total sample preparation time is 30 minutes.
[0102] The vacuum drying process described in step three of this embodiment involves drying in a vacuum drying oven at 80°C.
[0103] In step one of this embodiment, DFDL is produced by Shanghai Aladdin Biochemical Technology Co., Ltd., with a melting point of 25°C, a boiling point of 158°C, and a molecular weight of 154.25.
[0104] In step one of this embodiment, the IPDI used was manufactured by Shanghai Aladdin Biochemical Technology Co., Ltd., with a density of 1.06 g / cm³. 3 Its boiling point is 274℃.
[0105] In step one of this embodiment, DBTDL was produced by Shanghai Aladdin Biochemical Technology Co., Ltd., with a density of 1.066 g / ml and a molecular weight of 631.56.
[0106] In step one of this embodiment, the DMF was produced by Shanghai Aladdin Biochemical Technology Co., Ltd., with a density of 0.948 g / ml and a molecular weight of 73.095.
[0107] In step one of this embodiment, the BMI was produced by Shanghai Aladdin Biochemical Technology Co., Ltd., with a density of 1.4 g / cm3 and a molecular weight of 358.347.
[0108] In step one of this embodiment, furfurylamine was produced by Shanghai Aladdin Biochemical Technology Co., Ltd., with a density of 1.099 g / cm³. 3 Its molecular weight is 97.115.
[0109] In step two of this embodiment, KH570 was produced by Shanghai Aladdin Biochemical Technology Co., Ltd., and its density is 1.043 g / cm³. 3 Its boiling point is 255℃.
[0110] In step three of this embodiment, the LDPE used was produced by the Beijing Yanshan Branch of China Petroleum & Chemical Corporation, model LD100AC, with a density of 0.9205 g / cm³. 3 The melt flow index is 2.0 g / min.
[0111] In step three of this embodiment, antioxidant 1010 is produced by Dongguan Shanyi Plastic Co., Ltd., with a relative molecular mass of 1177.63 and a melting point of 115℃.
[0112] The reversible crosslinking agent prepared in this embodiment is denoted as SS-DA, and its structural formula is as follows: Figure 1 As shown.
[0113] The self-healing environmentally friendly cable insulation material prepared in this embodiment, based on disulfide bonds and DA reactions, underwent a breakdown self-healing test, and the results are as follows: Figure 2 As shown, the self-healing environmentally friendly cable insulation material can still achieve multiple self-repairs after experiencing three breakdown damages at the same location; the repair condition is 15 minutes at 80℃.
[0114] The self-healing environmentally friendly cable insulation material prepared in this embodiment, based on disulfide bonds and DA reactions, underwent a mechanical damage self-healing test, and the results are as follows: Figure 3 As shown, the self-healing environmentally friendly cable insulation material can still achieve multiple self-repairs after experiencing three mechanical damages at the same location; the repair condition is 15 minutes at 80℃.
[0115] The self-healing environmentally friendly cable insulation material prepared in this embodiment, based on disulfide bonds and DA reactions, underwent a self-healing test due to tree aging, and the results are as follows: Figure 4 As shown, the self-healing environmentally friendly cable insulation material can repair electrical treeing and water treeing aging; the repair condition is 15 minutes at 80℃.
[0116] This embodiment illustrates the self-healing principle, as shown below. Figure 5 As shown in the figure, it can be seen that self-healing environmentally friendly insulation materials can achieve self-healing and recyclability by reversibly recombinating chemical bonds.
[0117] The physical sample of the self-healing environmentally friendly cable insulation material based on disulfide bonds and DA reaction prepared in this embodiment is shown below. Figure 6 As shown.
Claims
1. A method for preparing a self-repairing environmentally friendly cable insulation material based on disulfide bonds and DA reactions, characterized by, It is carried out in the following steps: I. Preparation of reversible crosslinking agent: DFDL and IPDI are added to a three-necked flask purged with N2, then DMF and DBTDL are added, heated to 60℃ and kept for 2h, followed by the addition of hydroxyethyl methacrylate, heated to 75℃ and kept for 1h, then furoylamine dissolved in DMF is added dropwise, heated to 75℃ and kept for 1h, finally BMI is added and reacted for 24h, after washing and drying, the compound containing DA bond and disulfide bond after purification is obtained, named as reversible crosslinking agent, recorded as S-S-DA, ready for use; II. Grafting modification on the surface of nano-silica: Surface untreated SiO2 and acetone are added to a conical flask and magnetically stirred for 30min to obtain solution A; KH570, acetone and distilled water are mixed and magnetically stirred for 30min to obtain solution B; Solution A and solution B are mixed and magnetically stirred for 120min, then ultrasonic oscillation treatment is performed for 30min, after drying and grinding, KH570 grafted SiO2 particles are obtained; III. Preparation of self-repairing environment-friendly insulation material: DCP and S-S-DA are dissolved in anhydrous ethanol, then ball-milled LDPE is added, after stirring and mixing, it is left for 10h to obtain LDPE mixture; LDPE and antioxidant 1010 are added to a torque rheometer, melted until the torque is stable, then the LDPE mixture is added and melted for 2~4min, KH570 grafted SiO2 particles are added and melted for 2min to obtain composite material; The above composite material is cut into particles, vacuum dried after sample preparation by flat plate vulcanizer to obtain new crosslinked polyethylene, named as self-repairing environment-friendly cable insulation material based on disulfide bond and DA reaction, recorded as XLPE-S-S-DA-SiO2, i.e. the preparation method is completed.
2. The method for preparing a self-healing environmentally friendly cable insulation material based on disulfide bonds and DA reaction according to claim 1, characterized in that, The total amount of DFDL and IPDI in step I is 20g, and the molar ratio of n-NCO / n-OH is 1.
3. The method for preparing a self-healing environmentally friendly cable insulation material based on disulfide bonds and DA reaction according to claim 1, characterized in that, The amount of DMF and DBTDL in step I is 20mL and 2mL respectively; the amount of hydroxyethyl methacrylate is 10mL.
4. The method for preparing a self-healing environmentally friendly cable insulation material based on disulfide bonds and DA reaction according to claim 1, characterized in that, In step I, furoylamine dissolved in DMF: 1.92g of furoylamine is dissolved in 10mL of DMF; the amount of BMI is 7.16g.
5. The method for preparing a self-healing environmentally friendly cable insulation material based on disulfide bonds and DA reaction according to claim 1, characterized in that, In step II, the particle size of SiO2 is 20nm; the amount of SiO2 and acetone is 20g and 50ml respectively.
6. The method for preparing a self-healing environmentally friendly cable insulation material based on disulfide bonds and DA reaction according to claim 1, characterized in that, In step II, the amount of KH570, acetone and distilled water is 10ml, 20ml and 50ml respectively.
7. The method for preparing a self-healing environmentally friendly cable insulation material based on disulfide bonds and DA reaction according to claim 1, characterized in that, In step III, the parameters of melting are all temperature 110℃ and rotation speed 50r / min.
8. The method for preparing a self-healing environmentally friendly cable insulation material based on disulfide bonds and DA reaction according to claim 1, characterized in that, In step III, the amount of DCP, S-S-DA and anhydrous ethanol is 0.08g, 0.8g and 6mL respectively; the amount of LDPE is 6.3g.
9. The method for preparing a self-healing environmentally friendly cable insulation material based on disulfide bonds and DA reaction according to claim 1, characterized in that, In step III, the amount of LDPE and antioxidant 1010 is 33.7g and 0.12g respectively; the amount of KH570 grafted SiO2 particles is 0.4g.
10. The method for preparing a self-healing environmentally friendly cable insulation material based on disulfide bonds and DA reaction according to claim 1, characterized in that, The flat vulcanization machine mechanism described in step three: temperature setting 110 ℃, put into the composite material after cutting particles, start heating, 15 min after every 5 min 5 MPa, sample total duration is 30 min.