Environment-friendly insulated cable material and preparation method thereof

Abstract

The invention relates to an environment-friendly insulated cable material and a preparation method thereof, and the material is prepared by taking poly (terephthalic acid-adipic acid-butanediol copolyester) (PBAT), polyethylene-vinyl acetate copolymer (EVA) and maleic anhydride grafted low-density polyethylene (LDPE-g-MAH) as matrixes, the composite modified filler is prepared from zinc borate powder with the surface modified by aminopropyl, a graphene oxide-block polyether grafted hybrid, titanate coupling treatment silicon microspheres, a microencapsulated polyether type phase change material, a polyphosphazene flame retardant, cerium-doped nano titanium dioxide and a photosensitive free radical initiator; the preparation method comprises the steps of in-situ modification, grafting hybridization, micro-capsule coating with an interfacial polymerization method and the like, and efficient synergy is achieved through multiphase dispersion and ultraviolet crosslinking. The material has excellent thermal stability, flame retardance and flexibility, has green and degradable characteristics, is suitable for high-performance cable sheaths and insulation structures, and particularly meets the application requirements for low smoke, zero halogen and sustainability.

Description

Technical Field

[0001] The present invention relates to the technical field of new materials, and particularly to an environment-friendly insulating cable material and a preparation method thereof. Background Art

[0002] In the prior art, insulating cable materials widely use petrochemical-based polymer materials such as polyethylene, polyvinyl chloride, and crosslinked polyolefins as the main matrix, and are modified with flame retardants, reinforcing fillers, and processing aids to meet the usage requirements of cables in terms of electrical properties, mechanical strength, thermal stability, and environmental resistance. To improve the flame retardancy performance, aluminum hydroxide, antimony trioxide, or halogen-based flame retardants are usually added, and at the same time, inorganic nano-fillers are used to improve the mechanical properties and thermal conductivity. In terms of processing technology, methods such as melt blending, radiation crosslinking, and thermal curing molding are mostly used to prepare the insulating layer or sheath structure.

[0003] However, the above traditional cable materials have several key problems: First, most materials rely on petrochemical resources, are difficult to degrade, and have poor environmental friendliness; second, conventional halogen-free flame retardants affect the mechanical strength at high loads and have insufficient dispersibility; in addition, the interfacial bonding between the flame retardant, filler, and polymer is poor, easily leading to unstable performance of the composite system; finally, under long-term high-temperature operation or sudden overload, the material lacks effective thermal buffering ability, and there is a risk of thermal aging and functional failure. Therefore, there is an urgent need for a new type of insulating cable material with high flame retardancy, high flexibility, environmental degradability, and excellent thermal response performance.

[0004] Therefore, there is an urgent need for a new type of insulating cable material. Summary of the Invention

[0005] The present application provides an environment-friendly insulating cable material and a preparation method thereof to achieve the environmental friendliness and degradability of the material.

[0006] The present application provides an environment-friendly insulating cable material, which is prepared from the following raw materials in parts by weight: Poly(butylene adipate-co-terephthalate) (PBAT) 31 parts; Ethylene-vinyl acetate copolymer (EVA) 24 parts; Maleic anhydride grafted low density polyethylene (LDPE-g-MAH) 10 parts; Surface aminopropyl-modified zinc borate powder 7 parts; Graphene oxide-block polyether grafted covalent hybrid 4 parts; Silica microspheres treated with titanate coupling agent 5 parts; Surface-active microencapsulated phase change polyether material 3 parts; Polyphosphazene flame retardant 6 parts; Cerium-doped nano-titanium dioxide 2 parts; 1 part of a photosensitive free radical initiator.

[0007] The preparation method of the environment-friendly insulating cable material provided by the present application includes the following steps: Component pretreatment step S1: (1) Preparation of surface aminopropyl-modified zinc borate powder, including: Weigh 100 parts by weight of industrial-grade zinc borate powder and add it to 500 parts by weight of absolute ethanol, stir to form a uniform suspension; at room temperature, slowly add 5 parts by weight of γ-aminopropyltriethoxysilane (KH550), control the dropping time to be 30 minutes to ensure sufficient contact and hydrolysis condensation reaction; heat the mixed solution to 40 °C, and stir and react for 2 hours under the reflux condenser and normal-pressure air atmosphere; after the reaction is completed, quickly cool to room temperature, collect the precipitate by vacuum filtration, and wash it three times with absolute ethanol to remove the unreacted silane; place the collected wet precipitate in a vacuum drying oven at 60 °C for 6 hours, and grind the dried powder in a ball mill at 800 rpm for 15 minutes, and sieve to obtain surface aminopropyl-modified zinc borate powder with a particle size less than 200 mesh; (2) Preparation of graphene oxide-block polyether grafted covalent hybrid, including: Add 10 parts by weight of natural flake graphite powder and 5 parts by weight of sodium nitrate to 250 parts of concentrated sulfuric acid, stir for 15 minutes in an ice-water bath, and then slowly add 30 parts by weight of potassium permanganate, maintaining the reaction system temperature at 10 °C; heat the reaction system to 35 °C, continue to stir and react for 1 hour, add 250 parts by weight of deionized water dropwise to raise the system temperature to about 90 °C, and continue to react for 30 minutes; add 25 parts by weight of hydrogen peroxide solution (30%) to terminate the reaction, and the system becomes yellow; wash the reaction product repeatedly with dilute hydrochloric acid aqueous solution and deionized water until neutral, centrifuge to collect the precipitate, and freeze-dry for 48 hours to obtain graphene oxide (GO) dry powder; take 2 parts by weight of GO powder and add it to 100 parts by weight of anhydrous DMF, ultrasonically disperse it, add 0.2 parts by weight of basic regulator NaOH, and adjust the pH to 10; then add 4 parts by weight of polymer Pluronic F127, and react at 60 °C for 8 hours to form a polyether covalent hybrid structure with epoxy ring opening grafted on the GO surface; after the reaction is completed, wash the product with ethanol / water mixed solution until neutral, centrifuge and collect, freeze-dry, and then grind and sieve to obtain graphene oxide-block polyether grafted covalent hybrid powder; (3) Preparation of surface-active microencapsulated phase change polyether material, including: dissolving 50 parts by weight of polyoxyethylene ether as the core material in 100 parts by weight of the organic phase, where the organic phase is composed of a mixture of 20 parts by weight of cyclohexane and 80 parts by weight of n-hexane, and adding 2 parts by weight of hexamethylene diisocyanate HDI as the oil-phase prepolymer component; taking 150 parts by weight of deionized water as the aqueous phase, adding 3 parts by weight of Tween 80 as the emulsifier, and slowly dropping the organic phase, emulsifying for 15 minutes under the condition of 800 rpm to form a stable water-in-oil emulsion; slowly dropping 1 part by weight of ethylenediamine into the formed stable water-in-oil emulsion, controlling the addition time to be 10 minutes, so that a polyurea reaction occurs between the isocyanate at the water-oil interface to form a microcapsule shell; maintaining the stirring rate of the emulsification system at 800 rpm, controlling the reaction temperature at 30 °C, and the reaction time at 2 hours; after the reaction is completed, standing and cooling to room temperature, filtering with a 200-mesh filter cloth to obtain a milky white microcapsule precipitate, and then drying in a blast drying oven at 50 °C for 8 hours to obtain the surface-active microencapsulated polyether-based phase change material powder; Matrix mixing step S2: Mix and melt blend 31 parts by weight of poly(butylene adipate-co-terephthalate) (PBAT), 24 parts by weight of ethylene-vinyl acetate copolymer (EVA), and 10 parts by weight of maleic anhydride-grafted low-density polyethylene (LDPE-g-MAH) in an open mill at 85 °C for 8 minutes to obtain a flexible matrix blend A; Functional filler mixing step S3: Mix 7 parts by weight of the surface aminopropyl-modified zinc borate powder, 4 parts by weight of graphene oxide-block polyether grafted covalently hybridized material, and 3 parts by weight of the surface-active microencapsulated polyether-based phase change material powder obtained in the component pretreatment step S1 with 6 parts by weight of polyphosphazene flame retardant, 5 parts by weight of silicon microspheres treated with titanate coupling agent, and 2 parts by weight of cerium-doped nano-titanium dioxide respectively, dry blend in a high-speed disperser for 15 minutes, and after ultrasonic-assisted dispersion treatment, obtain a composite functional powder mixture B; Functional filler mixing S4: Gradually add the functional powder mixture B to the matrix blend A, melt blend in a twin-screw extruder at 110 °C for 10 minutes, add 1 part by weight of a photoinitiator radical after cooling to room temperature, and then irradiate with ultraviolet light at a wavelength of 365 nm in a closed light room for 5 minutes to induce the pre-activation but incomplete cross-linking of the initiator in the matrix to obtain an activated complex C; Molding process S5: Melt extrude the activated complex C again at 280 °C and inject it into a metal mold, apply a pressure of 20 MPa to mold it into a cable sheath or insulation layer product, and obtain the finished product of the environmentally friendly insulating cable material after water cooling and demolding.

[0008] Compared with the existing technology, the technical effects of the present invention are positive and obvious. By introducing bio-based polybutylene adipate terephthalate (PBAT) as the main matrix resin and combining EVA and LDPE-g-MAH to construct a flexible compatible structure, the dependence on traditional petrochemical polymers is significantly reduced, and the cable material is endowed with good degradability and ecological sustainability. A high-efficiency gas-phase - condensed-phase flame retardant system is synergistically constructed by using polyphosphazene flame retardant, aminopropyl-modified zinc borate, and cerium-doped nano-TiO2. Without adding halogen-based additives, the smoke suppression ability and thermal stability are significantly improved, meeting the environmental protection flame retardant standards. By preparing graphene oxide-block polyether grafted hybrids and titanate-coupled modified silica microspheres, the functional fillers form a stable distribution in the polymer matrix and the interfacial adhesion performance is improved, effectively enhancing the mechanical properties and electrical insulation properties of the material. The microencapsulated polyether-based phase change material releases latent heat under the condition of overload temperature rise, realizing the passive temperature control and thermal buffering functions of the cable sheath, prolonging the service life of the cable in complex environments, and enhancing the overall safety and reliability. Detailed implementation manners

[0009] In the following description, many specific details are set forth in order to provide a thorough understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar generalizations without departing from the connotation of the present application. Therefore, the present application is not limited by the specific implementations disclosed below.

[0010] The present application provides an environmentally friendly insulating cable material, which is prepared from the following raw materials in parts by weight: Polybutylene adipate terephthalate (PBAT) 31 parts; Ethylene-vinyl acetate copolymer (EVA) 24 parts; Maleic anhydride grafted low density polyethylene (LDPE-g-MAH) 10 parts; Aminopropyl-modified zinc borate powder 7 parts; Graphene oxide-block polyether grafted covalent hybrid 4 parts; Silica microspheres treated with titanate coupling agent 5 parts; Surface-active microencapsulated phase change polyether material 3 parts; Polyphosphazene flame retardant 6 parts; Cerium-doped nano-titanium dioxide 2 parts; Photosensitive free radical initiator 1 part.

[0011] The preparation method of the environmentally friendly insulating cable material includes the following steps: Component pretreatment step S1: (1) Preparation of aminopropyl-modified zinc borate powder, including: Weigh 100 parts by weight of industrial-grade zinc borate powder and add it to 500 parts by weight of absolute ethanol, and stir to form a homogeneous suspension; at room temperature, slowly dropwise add 5 parts by weight of γ-aminopropyltriethoxysilane (KH550), and control the dropping time to be 30 minutes to ensure sufficient contact and hydrolysis condensation reaction; heat the mixed solution to 40 °C, and stir and react for 2 hours under an open reflux condenser and normal-pressure air atmosphere; after the reaction is completed, quickly cool to room temperature, collect the precipitate by vacuum filtration, and wash it three times with absolute ethanol to remove the unreacted silane; place the collected wet precipitate in a vacuum drying oven at 60 °C and dry it for 6 hours, and grind the dried powder in a ball mill at 800 rpm for 15 minutes, and sieve it to obtain surface aminopropyl-modified zinc borate powder with a particle size less than 200 mesh; (2) Prepare graphene oxide-block polyether grafted covalent hybrids, including: add 10 parts by weight of natural flake graphite powder and 5 parts by weight of sodium nitrate to 250 parts of concentrated sulfuric acid, stir for 15 minutes in an ice-water bath, and then slowly add 30 parts by weight of potassium permanganate, maintaining the reaction system temperature at 10 °C; heat the reaction system to 35 °C, continue to stir and react for 1 hour, dropwise add 250 parts by weight of deionized water to raise the system temperature to about 90 °C, and continue to react for 30 minutes; dropwise add 25 parts by weight of hydrogen peroxide solution (30%) to terminate the reaction, and the system turns yellow; wash the reaction product repeatedly with dilute hydrochloric acid aqueous solution and deionized water until neutral, centrifuge to collect the precipitate, and freeze-dry for 48 hours to obtain graphene oxide (GO) dry powder; take 2 parts by weight of GO powder and add it to 100 parts by weight of anhydrous DMF, ultrasonically disperse it, add 0.2 parts by weight of basic regulator NaOH, and adjust the pH to 10; then add 4 parts by weight of polymer Pluronic F127, and react at 60 °C for 8 hours to form a polyether covalent hybrid structure with epoxy ring-opening grafted on the GO surface; after the reaction is completed, wash the product with an ethanol / water mixed solution until neutral, centrifuge to collect it, freeze-dry it, and then grind and sieve it to obtain graphene oxide-block polyether grafted covalent hybrid powder; (3) Preparation of surface-active microencapsulated phase change polyether material, including: dissolving 50 parts by weight of polyoxyethylene ether as the core material in 100 parts by weight of the organic phase, where the organic phase is composed of a mixture of 20 parts by weight of cyclohexane and 80 parts by weight of n-hexane, and adding 2 parts by weight of hexamethylene diisocyanate (HDI) as the oil-phase prepolymer component; taking 150 parts by weight of deionized water as the aqueous phase, adding 3 parts by weight of Tween 80 as the emulsifier, and slowly dropping the organic phase, emulsifying for 15 minutes under the condition of 800 rpm to form a stable water-in-oil emulsion; slowly dropping 1 part by weight of ethylenediamine into the formed stable water-in-oil emulsion, controlling the addition time to be 10 minutes, so that a polyurea reaction occurs between the isocyanate at the water-oil interface to form a microcapsule shell; maintaining the stirring rate of the emulsification system at 800 rpm, controlling the reaction temperature to be 30 °C, and the reaction time to be 2 hours; after the reaction is completed, standing and cooling to room temperature, filtering with a 200-mesh filter cloth to obtain a milky white microcapsule precipitate, and then drying in a blast drying oven at 50 °C for 8 hours to obtain the surface-active microencapsulated polyether-based phase change material powder; Matrix mixing step S2: Mixing and melting 31 parts by weight of poly(butylene adipate-co-terephthalate) (PBAT), 24 parts by weight of ethylene-vinyl acetate copolymer (EVA), and 10 parts by weight of maleic anhydride-grafted low-density polyethylene (LDPE-g-MAH) in an open mill at 85 °C for 8 minutes to obtain a flexible matrix blend A; Functional filler mixing step S3: Mixing 7 parts by weight of the surface aminopropyl-modified zinc borate powder, 4 parts by weight of graphene oxide-block polyether grafted covalent hybrid, and 3 parts by weight of the surface-active microencapsulated polyether-based phase change material powder obtained in the component pretreatment step S1 with 6 parts by weight of polyphosphazene flame retardant, 5 parts by weight of silicon microspheres treated with titanate coupling, and 2 parts by weight of cerium-doped nano-titanium dioxide respectively, dry mixing in a high-speed disperser for 15 minutes, and then performing ultrasonic-assisted dispersion treatment to obtain a composite functional powder mixture B; Functional filler mixing S4: Gradually adding the functional powder mixture B to the matrix blend A, melting and blending in a twin-screw extruder at 110 °C for 10 minutes, cooling to room temperature, adding 1 part by weight of a photoinitiator, and then irradiating with ultraviolet light of wavelength 365 nm in a closed light room for 5 minutes to induce the pre-activation but incomplete cross-linking of the initiator in the matrix to obtain an activated complex C; Molding process S5: Melting and extruding the activated complex C again at 280 °C and injecting it into a metal mold, applying a pressure of 20 MPa to form a cable sheath or insulation layer product, and obtaining the finished product of the environmentally friendly insulating cable material after water cooling and demolding.

[0012] In this embodiment, the polyphosphazene flame retardant is preferably polyphenoxyphosphazene, which can be purchased on the market.

[0013] In this embodiment, the silicon microspheres treated with titanate coupling are preferably spherical silica particles with a particle size of about 500 nm, and their surfaces are treated with isopropyltris(N-ethylaminoethyl) titanate (trade name KR-38S) coupling agent to improve their dispersibility and interfacial compatibility in the polymer matrix.

[0014] The preparation method is as follows: Take 100 parts of nano-silicon microspheres (average particle size 500 nm), disperse them in 500 parts of 95% ethanol aqueous solution, add 2 parts of KR-38S coupling agent, stir magnetically at room temperature for 1 hour, then heat up to 60 °C and maintain the reaction for 2 hours to enable the coupling agent to chemically adsorb and partially condense on the surface of the silicon microspheres. The obtained product is centrifuged and washed, vacuum dried at 60 °C for 6 hours, ground and sieved to obtain surface-modified silicon microsphere powder, which is suitable for reinforcement and interfacial regulation in composite materials.

[0015] In this embodiment, the cerium-doped nano-titanium dioxide is preferably Ce 4+ element-doped anatase TiO2 nanoparticles, where the Ce / Ti molar ratio is controlled at 5%, and the particle size is controlled between 20 - 30 nm. This material has excellent antioxidant and free radical inhibition capabilities, and can significantly improve the thermal aging stability and UV weather resistance of cable materials.

[0016] The preparation method is as follows: Take 95 parts of tetrabutyl titanate (Ti(OBu)4) and 5 parts of cerium nitrate (Ce(NO3)3·6H2O) and dissolve them in 100 parts of absolute ethanol, and ultrasonically disperse for 15 minutes; slowly add 100 parts of aqueous ethanol (volume fraction 80%) as a hydrolysis agent, maintain the pH at 3, and hydrolyze at room temperature for 4 hours; the obtained sol is aged for 24 hours and then dried into a gel, and the gel is calcined at 500 °C for 2 hours to obtain light yellow Ce-doped TiO2 nano-powder. This powder has good thermal stability and dispersibility, and is suitable for polymer composite systems.

[0017] Compared with the traditional cable material system using polyethylene or polyvinyl chloride as the matrix and antimony trioxide and aluminum hydroxide as flame retardants, the present invention constructs a flexible blend system by introducing bio-based PBAT, EVA and LDPE-g-MAH, and compositing aminopropyl-modified zinc borate, polyphosphazene flame retardant and graphene hybrid filler, which significantly improves the flame retardancy and thermal aging stability. At the same flame retardant filling ratio (about 15%), the limiting oxygen index (LOI) of traditional materials is generally about 22%, while the materials of the present invention can reach 28.6% after testing, achieving a better flame retardancy grade without increasing the smoke density and halogen residue.

[0018] In thermogravimetric analysis (TGA), the mass loss rate of traditional PVC cable sheath materials exceeds 40% at 300 °C. However, after introducing Ce-doped TiO2 and graphene hybrids in the present invention, the mass loss of the material is controlled within 19.3% at the same temperature, effectively delaying the thermal degradation rate of the material, indicating that the material of the present invention is more stable under continuous current-carrying operation or short-term high-temperature impact during overload.

[0019] In terms of flexibility, the elongation at break of the material of the present invention reaches 220%, which is significantly improved compared with traditional low-smoke and halogen-free materials (about 180%), contributing to the mechanical adaptability of the cable during bending, winding or construction.

[0020] In addition, the microencapsulated polyether phase change filler in the material of the present invention releases latent heat at about 45 °C, and the latent heat per unit mass reaches 110 J / g, having significant temperature control and slow-release capabilities. It can form a "thermal buffer zone" for the cable under sudden overheating conditions. In the thermal imaging test, the surface heating rate of the cable outer sheath is reduced by more than about 30%.

[0021] From the above data, it can be seen that the present invention not only achieves a breakthrough in environmental protection performance, but also significantly improves in terms of flame retardancy, safety and material service life compared with the prior art.

[0022] Although this application is disclosed above with preferred embodiments, it is not intended to limit this application. Any person skilled in the art can make possible changes and modifications without departing from the spirit and scope of this application. Therefore, the protection scope of this application should be subject to the scope defined by the claims of this application.

Claims

1. An environmentally friendly insulating cable material, characterized in that, Prepared from the following raw materials in parts by weight: Poly(butylene adipate-co-terephthalate) (PBAT) 31 parts; Ethylene-vinyl acetate copolymer (EVA) 24 parts; Maleic anhydride grafted low density polyethylene (LDPE-g-MAH) 10 parts; Surface aminopropyl modified zinc borate powder 7 parts; Graphene oxide-block polyether grafted covalent hybrid 4 parts; Silica microspheres treated with titanate coupling agent 5 parts; Surface active microencapsulated phase change polyether material 3 parts; Polyphosphazene flame retardant 6 parts; Cerium doped nano-titanium dioxide 2 parts; Photosensitive free radical initiator 1 part.

2. A preparation method of the environmentally friendly insulating cable material according to claim 1, characterized in that, Including the following steps: Component pretreatment step S1, including preparing surface aminopropyl modified zinc borate powder; preparing graphene oxide-block polyether grafted covalent hybrid; preparing surface active microencapsulated phase change polyether material; Matrix mixing step S2: Mix and melt blend 31 parts of poly(butylene adipate-co-terephthalate) (PBAT), 24 parts of ethylene-vinyl acetate copolymer (EVA) and 10 parts of maleic anhydride grafted low density polyethylene (LDPE-g-MAH) in an open mill at 85 °C for 8 minutes to obtain a flexible matrix blend A; Functional filler mixing step S3: Mix 7 parts by weight of the surface aminopropyl modified zinc borate powder, 4 parts by weight of the graphene oxide-block polyether grafted covalent hybrid, and 3 parts by weight of the surface active microencapsulated polyether type phase change material powder obtained in the component pretreatment step S1 with 6 parts of polyphosphazene flame retardant, 5 parts of silica microspheres treated with titanate coupling agent, and 2 parts of cerium doped nano-titanium dioxide respectively, dry blend in a high speed disperser for 15 minutes, and after ultrasonic assisted dispersion treatment, obtain a composite functional powder mixture B; Functional filler mixing S4: Gradually add the functional powder mixture B to the matrix blend A, melt blend in a twin screw extruder at 110 °C for 10 minutes, cool to room temperature, add 1 part of photosensitive free radical initiator, and then irradiate with ultraviolet light of wavelength 365 nm in a closed light chamber for 5 minutes to induce pre-activation but incomplete crosslinking of the initiator in the matrix to obtain an activated composite C; Molding process S5: Melt extrude the activated composite C again at 280 °C and inject it into a metal mold, apply a pressure of 20 MPa to mold it into a cable sheath or insulation layer product, and obtain the finished product of the environmentally friendly insulating cable material after water cooling and shaping and peeling off the mold.

3. The preparation method of the environmentally friendly insulating cable material according to claim 2, characterized in that, The preparation of the surface aminopropyl modified zinc borate powder includes: Weigh 100 parts by weight of industrial grade zinc borate powder and add it to 500 parts by weight of absolute ethanol, and stir to form a homogeneous suspension; at room temperature, slowly dropwise add 5 parts by weight of γ-aminopropyltriethoxysilane (KH550), and control the dropping time to be 30 minutes to ensure sufficient contact and hydrolysis condensation reaction; heat the mixed solution to 40 °C, and stir and react for 2 hours under the condition of opening the reflux condenser and in an atmospheric air atmosphere; after the reaction is completed, quickly cool to room temperature, collect the precipitate by vacuum filtration, and wash it three times with absolute ethanol to remove the unreacted silane; place the collected wet precipitate in a vacuum drying oven at 60 °C and dry it for 6 hours, and grind the dried powder in a ball mill at 800 rpm for 15 minutes, and sieve it to obtain surface aminopropyl-modified zinc borate powder with a particle size less than 200 mesh.

4. The preparation method of the environmentally friendly insulating cable material according to claim 2, characterized in that, The preparation of graphene oxide-block polyether grafted covalent hybrid includes: Add 10 parts by weight of natural flake graphite powder and 5 parts by weight of sodium nitrate to 250 parts of concentrated sulfuric acid, stir for 15 minutes in an ice-water bath, and then slowly add 30 parts by weight of potassium permanganate, maintaining the reaction system temperature at 10 °C; heat the reaction system to 35 °C, continue to stir and react for 1 hour, dropwise add 250 parts by weight of deionized water to raise the system temperature to about 90 °C, and continue to react for 30 minutes; dropwise add 25 parts by weight of hydrogen peroxide solution (30%) to terminate the reaction, and the system turns yellow; wash the reaction product repeatedly with dilute hydrochloric acid aqueous solution and deionized water until neutral, centrifuge to collect the precipitate, and freeze-dry for 48 hours to obtain graphene oxide (GO) dry powder; take 2 parts by weight of GO powder and add it to 100 parts by weight of anhydrous DMF, ultrasonically disperse it, then add 0.2 parts by weight of basic regulator NaOH to adjust the pH to 10; then add 4 parts by weight of polymer Pluronic F127, and react at 60 °C for 8 hours to form a polyether covalent hybrid structure with epoxy ring-opening grafted on the GO surface; after the reaction is completed, wash the product with ethanol / water mixed solution until neutral, centrifuge and collect it, then freeze-dry and grind and sieve it to obtain graphene oxide-block polyether grafted covalent hybrid powder.

5. The preparation method of the environmentally friendly insulating cable material according to claim 2, characterized in that, The preparation of surface-active microencapsulated phase change polyether material includes: 50 parts by weight of polyoxyethylene ether was dissolved in 100 parts by weight of the organic phase. The organic phase was composed of a mixture of 20 parts by weight of cyclohexane and 80 parts by weight of n-hexane, and 2 parts by weight of hexamethylene diisocyanate (HDI) was added as the oil-phase prepolymer component; 150 parts by weight of deionized water was taken as the aqueous phase, 3 parts by weight of Tween 80 was added as an emulsifier, and the organic phase was slowly added dropwise. Emulsification was carried out at 800 rpm for 15 minutes to form a stable water-in-oil emulsion; 1 part by weight of ethylenediamine was slowly added dropwise to the formed stable water-in-oil emulsion, and the addition time was controlled to be 10 minutes to cause a polyurea reaction with the isocyanate at the water-oil interface to form a microcapsule shell; the emulsification system was maintained at a stirring rate of 800 rpm, the reaction temperature was controlled at 30 °C, and the reaction time was 2 hours; after the reaction was completed, it was allowed to stand and cool to room temperature, filtered through a 200-mesh filter cloth to obtain a milky white microcapsule precipitate, and then dried in a blast drying oven at 50 °C for 8 hours to obtain the surface-active microencapsulated polyether-based phase change material powder.