Lightweight and High-Strength Power Cable Based on Composite Materials and Its Applications

Abstract

The present invention discloses a lightweight and high-strength power cable based on composite materials and its application, belonging to the technical field of cable preparation, and is used to solve the technical problem that the lightweight and electromagnetic interference resistance performance of lightweight cables in the prior art need to be further improved; the present invention includes a conductor layer, a lightweight shielding layer, a wrapping layer, and a composite sheath layer arranged in sequence from inside to outside. A modified carbon sphere is introduced into the titanium dioxide aerogel structure for filling and loading copper particles, and the obtained composite aerogel is used as the filling material of the lightweight shielding layer, and the modified carbon sphere is used as the cross-linking agent and filling material of lightweight polyurethane. The composite aerogel and lightweight polyurethane significantly reduce the cable density and significantly improve its lightweight performance, and through the synergistic cooperation of copper particles, titanium dioxide aerogel structure, and hollow carbon spheres, the electromagnetic interference resistance performance of the material is significantly improved.

Description

Technical Field

[0001] The present invention relates to the technical field of special cable preparation, and particularly relates to a lightweight and high-strength power cable based on composite materials and its applications. Background Art

[0002] Lightweight and electromagnetic shielding technologies are two core paths for the development of power cables, respectively addressing the requirements for weight optimization and anti-interference performance. These two technologies have achieved remarkable progress through material innovation and technological breakthroughs.

[0003] In terms of lightweight, cables have gradually evolved from traditional copper cables to aluminum alloy and carbon fiber composite materials, significantly reducing weight while maintaining strength. In the field of electromagnetic shielding, shielding technologies have gradually evolved from early copper meshes and aluminum foils to nano-materials and flexible composite materials, further improving shielding effectiveness and material adaptability. The maturity of these technologies provides more lightweight, durable, and excellent anti-interference power transmission solutions for fields such as aerospace, electric vehicles, and smart grids.

[0004] The prior art CN118919148B discloses a lightweight flexible drum cable, including an outer sheath, a reinforcing layer, an inner sheath, a mica tape layer, a ground wire, and a main wire. The apparent density of the inner sheath ≤ 0.35 g / cm 3 , and the tensile strength ≥ 3.5 MPa. The provided drum cable with an inner sheath is lightweight and high-strength, which can avoid adverse effects on the normal operation of equipment and the performance of the cable itself due to excessive weight.

[0005] However, the above patent content is to prepare a lightweight flexible cable by foaming the inner sheath layer. However, after foaming the inner sheath layer, a large number of micro-pores are introduced, weakening the electrical conductivity and shielding integrity of the sheath layer, resulting in a significant reduction in electromagnetic interference shielding ability. In a high electromagnetic interference environment, this performance degradation may have an adverse impact on the stability and safety of equipment operation. Secondly, the lightweight improvement of a single component also has limitations in overall performance improvement. Due to the overall complexity of the cable structure, simply optimizing the weight of a certain component cannot meet the comprehensive requirements of modern power transmission for lightweight and excellent electromagnetic shielding performance.

[0006] A solution is proposed for the technical defects in this regard. Summary of the Invention

[0007] The purpose of the present invention is to provide a lightweight and high-strength power cable based on composite materials and its applications, aiming to solve the technical problem that the lightweight and anti-electromagnetic interference performance of lightweight cables in the prior art need to be further improved.

[0008] The object of the present invention can be achieved by the following technical solutions: A lightweight and high-strength power cable based on composite materials, comprising a conductor layer, a lightweight shielding layer, a wrapping layer, and a composite sheath layer arranged in sequence from the inside out;

[0009] The conductor layer is composed of several copper wires stranded and coated with polyvinylidene fluoride on the surface; the wrapping layer is obtained by wrapping a polyvinylidene fluoride wrapping tape around the outside of the composite aerogel; the composite sheath layer is composed of composite cable material;

[0010] The lightweight shielding layer is obtained by wrapping the composite aerogel on the surface of the conductor layer and fixing it with a wrapping tape; the composite sheath layer is obtained by melting and extruding the composite cable material onto the surface of the wrapping layer and shaping it. Among them, the composite cable material is obtained by mixing lightweight polyurethane, flame retardant, plasticizer, ultraviolet absorber, and lubricant in a mass ratio of 70 - 85 g: 10 - 15 g: 5 - 8 g: 0.2 - 0.5 g: 3 - 5 g.

[0011] Further, the flame retardant is one or both of melamine and hexabromocyclododecane; the plasticizer is one or more of dioctyl phthalate, diisooctyl phthalate, and epoxidized soybean oil; the ultraviolet absorber is one or both of 2 - hydroxy - 4 - octyloxybenzophenone and bis(2,2,6,6 - tetramethylpiperidinyl) sebacate; the lubricant is one or more of calcium stearate, oxidized polyethylene wax, and montan wax.

[0012] Further, the preparation method of the composite aerogel includes the following steps:

[0013] A1. Add modified carbon spheres, tetrabutyl titanate, and deionized water to a reaction kettle, stir at room temperature for 10 - 15 min, then drop the copper source solution into the reaction kettle, and continue to stir for 5 - 8 min to obtain a composite solution;

[0014] A2. Transfer the composite solution to a hydrothermal reaction kettle, raise the temperature of the hydrothermal reaction kettle to 160 - 200 °C, keep the temperature for reaction for 20 - 28 h, and perform post - treatment to obtain a gel precursor;

[0015] A3. Transfer the gel precursor to a tubular furnace, calcine and reduce it to obtain the composite aerogel.

[0016] Reaction principle for preparing the composite aerogel: Under hydrothermal conditions, the siloxane structure on the surface of tetrabutyl titanate and modified carbon spheres undergoes hydrolysis to produce a gel structure, and the copper nitrate molecules inside the copper source solution adhere to the surface of the gel structure. After freeze - drying, a gel precursor is obtained. After high - temperature hydrogen reduction, the copper salt on the surface of the gel precursor is reduced to copper particles, and finally the composite aerogel is prepared.

[0017] Further, in step A1, the stirring rate of the reaction kettle is 60 - 80 rpm, and the dosage ratio of the modified carbon spheres, tetrabutyl titanate, deionized water and copper source solution is 4 - 6 g: 7 - 8 g: 60 - 80 mL: 10 - 20 mL. The copper source solution is obtained by mixing copper nitrate and ethylene glycol in a dosage ratio of 1 - 2 g: 8 - 10 mL;

[0018] Further, in step A2, the post-treatment includes: after the reaction is completed, after the temperature of the hydrothermal reaction kettle is reduced to room temperature, the material is transferred to a stainless steel mold, and then the stainless steel mold is transferred to a copper column immersed in liquid nitrogen. After standing for 20 - 30 min, the mold is transferred to a vacuum dryer, the temperature is set to 30 - 50 °C, the vacuum degree is 3 - 5 mBar, and vacuum drying is carried out for 1 - 2 h to obtain a gel precursor;

[0019] Further, in step A3, the calcination reduction operation is as follows: after the tubular furnace is purged with nitrogen, it is heated to 400 - 500 °C at a heating rate of 3 - 5 °C / min, then the nitrogen is cut off, and a mixed gas with a volume ratio of hydrogen to nitrogen of 4 - 5 mL: 95 mL is introduced into the tubular furnace. After holding for 30 - 40 min, it is naturally cooled to room temperature to obtain a composite aerogel.

[0020] Further, the preparation method of the modified carbon spheres includes the following steps:

[0021] B1. Disperse the nano-calcium carbonate powder in a hydrothermal reaction kettle containing a carbon source solution. After stirring at room temperature for 5 - 8 min, the temperature of the hydrothermal reaction kettle is raised to 140 - 160 °C, and the reaction is held for 6 - 8 h. After post-treatment, carbon-coated nano-spheres are obtained;

[0022] B2. Add the carbon-coated nano-spheres and 49.0 wt% sulfuric acid to the reaction kettle. After stirring at room temperature for 10 - 15 min, add potassium permanganate to the reaction kettle. The temperature of the reaction kettle is raised to 40 - 50 °C, and the reaction is held for 1 - 2 h. After post-treatment, carbon-shell hollow spheres are obtained;

[0023] B3. Add the hollow carbon spheres and N,N-dimethylformamide to the reaction kettle, purge with nitrogen, after stirring at room temperature for 5 - 8 min, add 3-isocyanatopropyltrimethoxysilane solution to the reaction kettle. The temperature of the reaction kettle is raised to 30 - 50 °C, and the treatment is held for 30 - 40 min. After post-treatment, modified carbon spheres are obtained.

[0024] The reaction principle for preparing the modified carbon spheres is as follows: under hydrothermal reaction, glucose in the carbon source solution undergoes dehydration and adheres to the surface of the nano-calcium carbonate powder to form an organic layer. After high-temperature carbonization, the nano-calcium carbonate powder is removed by an acidic oxidation solution, and then the carbon layer is oxidized and a siloxane structure is modified on its surface to obtain the modified carbon spheres.

[0025] Further, in step B1, the stirring rate of the reaction kettle is 60 - 80 rpm, the dosage ratio of nano - calcium carbonate powder to carbon source solution is 1 - 2 g:20 - 24 mL, the carbon source solution is a glucose solution with a concentration of 0.5 - 0.8 M, and the post - treatment includes: after the reaction is completed, when the temperature of the reaction kettle drops to room temperature, filter the reaction solution by suction to collect the filter cake, transfer the filter cake to a drying oven at 60 - 80 °C for vacuum drying, after the filter cake reaches a constant weight, transfer the filter cake to a tubular furnace, after introducing nitrogen for protection, the tubular furnace is heated to 720 °C at a heating rate of 5 °C / min, keep the temperature for calcination for 5 h, and then cool naturally to obtain carbon - coated nanospheres;

[0026] Further, in step B2, the stirring rate of the reaction kettle is 60 - 80 rpm, the dosage ratio of carbon - coated nanospheres, 49.0 wt% sulfuric acid and potassium permanganate is 2 - 3 g:30 - 36 mL:6 - 8 g, and the post - treatment includes: after the reaction is completed, when the temperature of the reaction kettle drops to room temperature, add a protective sodium hydroxide solution to the reaction kettle, adjust the reaction solution to be neutral, filter the reaction solution by suction to collect the filter cake, wash the filter cake 3 - 5 times with anhydrous ethanol and deionized water, transfer the filter cake to a drying oven at 60 - 80 °C for vacuum drying until the filter cake reaches a constant weight to obtain carbon - shell hollow spheres;

[0027] Further, in step B3, the stirring rate of the reaction kettle is 60 - 80 rpm, the dosage ratio of hollow carbon spheres, N,N - dimethylformamide and 3 - isocyanatopropyltrimethoxysilane solution is 4 - 5 g:30 - 40 mL:10 - 12 mL, the 3 - isocyanatopropyltrimethoxysilane solution is obtained by mixing 3 - isocyanatopropyltrimethoxysilane and N,N - dimethylformamide according to the dosage ratio of 2 - 3 g:10 - 15 mL, and the post - treatment includes: after the reaction is completed, when the temperature of the reaction kettle drops to room temperature, filter the reaction solution by suction to collect the filter cake, wash the filter cake 3 - 5 times with anhydrous ethanol, transfer the filter cake to a drying oven at 60 - 80 °C for vacuum drying until the filter cake reaches a constant weight to obtain modified carbon spheres.

[0028] Further, the preparation method of light polyurethane includes the following steps:

[0029] C1. Add hydroxyl silicone oil, hydroquinone di - hydroxyethyl ether, N,N - dimethylformamide and dibutyltin dilaurate into a reaction kettle, after introducing nitrogen for protection, add isophthalic diisocyanate solution to the reaction kettle, raise the temperature of the reaction kettle to 50 - 60 °C, keep the temperature for reaction for 1 - 2 h, and perform post - treatment to obtain modified polyurethane;

[0030] C2. Add modified polyurethane and N,N-dimethylformamide into a reaction kettle and stir. After the temperature of the reaction kettle rises to 40 - 60 °C, add 3-isocyanatopropyltrimethoxysilane solution into the reaction kettle. After heat preservation and stirring for 30 - 40 min, add deionized water and sodium hydroxide powder into the reaction kettle. After heat preservation and stirring for 5 - 8 min, add modified carbon spheres into the reaction kettle. After heat preservation reaction for 20 - 30 min, conduct post-treatment to obtain lightweight polyurethane.

[0031] The reaction equation for preparing lightweight polyurethane is:

[0032]

[0033] In the formula:

[0034] ;

[0035] ;

[0036] ;

[0037] “ ” represents modified carbon spheres; “*” represents the active connection site of the organic chain segment.

[0038] The reaction principle for preparing lightweight polyurethane is: During the reaction process, using m-xylylene diisocyanate as a cross-linking agent, under the condition of a catalyst, the isocyanate group on m-xylylene diisocyanate acts as an active group to condense with the hydroxyl groups on hydroquinone di(2-hydroxyethyl) ether and hydroxyl silicone oil, forming a segment in which the hydroquinone di(2-hydroxyethyl) ether segment and the polysiloxane segment are co-embedded. And through hydrolysis, the isocyanate group is capped and transformed into an amino-capped modified polyurethane. The isocyanate group on 3-isocyanatopropyltrimethoxysilane can react with the amino group capped on the modified polyurethane to form a siloxane segment, and through co-hydrolysis with the modified carbon spheres, lightweight polyurethane is obtained.

[0039] Furthermore, in step C1, the dosage ratio of hydroxyl silicone oil, hydroquinone di(2-hydroxyethyl) ether, N,N-dimethylformamide, dibutyltin dilaurate and m-xylylene diisocyanate solution is 8 - 10 g: 1 - 2 g: 40 - 60 mL: 0.2 - 0.5 g: 10 - 12 mL. The m-xylylene diisocyanate solution is obtained by mixing m-xylylene diisocyanate and N,N-dimethylformamide according to the dosage ratio of 3 - 4 g: 10 - 15 mL. The post-treatment includes: after the reaction is completed, add purified water into the reaction kettle, raise the temperature of the reaction kettle to 120 - 140 °C, and conduct vacuum distillation until no liquid is drawn out to obtain modified polyurethane;

[0040] Furthermore, the stirring rate of the reaction kettle is 60 - 80 rpm. In step C2, the dosage ratio of the modified polyurethane, N,N-dimethylformamide, 3-isocyanatopropyltrimethoxysilane solution, and modified carbon spheres is 8 - 10 g : 40 - 50 mL : 10 - 15 mL : 2 - 3 g. The 3-isocyanatopropyltrimethoxysilane solution is obtained by mixing 3-isocyanatopropyltrimethoxysilane and N,N-dimethylformamide according to the dosage ratio of 2 - 3 g : 10 - 15 mL. The post-treatment includes: after the reaction is completed, when the reaction kettle cools to room temperature, the reaction solution is added into a rotary evaporator with a water bath temperature of 80 - 100 °C, and vacuum distillation is carried out until no liquid is taken out to obtain light polyurethane.

[0041] Furthermore, the preparation method of the lightweight cable includes the following steps:

[0042] S1. After coating the surface of the conductor layer with the composite aerogel, a polyvinylidene fluoride wrapping tape is used to wrap around the outside of the composite aerogel to obtain a lightweight shielding layer and a wrapping layer.

[0043] S2. The composite cable material is added into a twin-screw extruder, melted and extruded onto the surface of the wrapping layer, and naturally cooled to obtain the lightweight cable.

[0044] Furthermore, the temperatures of the eight temperature zones of the twin-screw extruder from the feed port towards the discharge port are 200 °C, 215 °C, 215 °C, 220 °C, 220 °C, 230 °C, 230 °C, and 240 °C in sequence. The main machine speed of the twin-screw extruder is 80 - 120 rpm, and the pressure is 100 - 150 bar.

[0045] The present invention also proposes an application of the lightweight high-strength power cable based on the composite material. The above-mentioned lightweight high-strength power cable based on the composite material is applied to aerospace, high-altitude cable erection, ship power supply, and ocean engineering.

[0046] The present invention has the following beneficial effects:

[0047] 1. The present invention prepares carbon-coated nanospheres by using nano-calcium carbonate powder as a template. While removing calcium carbonate in an acidic potassium permanganate solution, the carbon layer is oxidized to obtain carbon-shell hollow spheres. A highly hydrolyzable silane coupling agent is modified on its surface to obtain modified carbon spheres. The modified carbon spheres are used as filling materials to hydrothermally hydrolyze tetrabutyl titanate to obtain a gel precursor. After copper nitrate is loaded and reduced on it, a composite aerogel is obtained. The porous structure of the composite aerogel and the hollow carbon spheres cooperate synergistically to significantly reduce the density of the material, significantly improving the lightweight performance of the material. And in the process of preparing lightweight polyurethane, the modified carbon spheres are used as filling materials and chain extenders, hybridizing polyurethane segments and reducing the density of polyurethane materials. The complex three-dimensional spatial structure of polyurethane segments and the spherical buffer structure of modified carbon spheres significantly enhance the cantilever beam impact strength of lightweight cables, significantly improving the strength of cable materials.

[0048] 2. The copper particles in the composite aerogel structure prepared by the present invention contribute to the uniform dispersion of heat through their good thermal conductivity, preventing local overheating and indirectly enhancing the thermal stability and high-temperature resistance of the material. Titanium dioxide, as an inorganic compound with high thermal stability, can form a protective ceramic layer at high temperatures, effectively preventing the spread of flames and enhancing the overall flame retardant effect. The hollow carbon spheres in the composite aerogel structure and lightweight polyurethane utilize their porous structure and low-density characteristics. The hollow carbon spheres form a charred layer and enhance the thermal insulation effect, preventing the spread of flames and helping to reduce heat conduction. And with their low thermal conductivity and high specific surface area, they provide additional thermal insulation protection, optimizing the synergistic effect of other components, thereby enhancing the flame retardant ability of the overall material. Through the synergistic effect of these three, the cable can effectively delay the combustion process under high-temperature and flame exposure conditions, prevent the spread of flames, and provide excellent flame retardant performance.

[0049] 3. The composite aerogel prepared by the present invention is used as a filling material for a lightweight shielding layer. The copper particles loaded in its structure absorb and reflect electromagnetic waves through their excellent conductivity. The titanium dioxide structure utilizes its semiconductor characteristics and strong photoelectric effect to enhance the absorption and reflection effect of high-frequency electromagnetic waves and provide a better dispersion environment for copper particles, improving the overall shielding ability. The hollow carbon spheres in the composite aerogel structure and lightweight polyurethane rely on their porous structure, lightweight characteristics and conductivity to increase the reflection and scattering effects of the material and reduce the density, making the material more balanced and efficient in anti-electromagnetic interference. In addition, as a carrier, the aerogel matrix optimizes the cooperation between copper particles, titanium dioxide and hollow carbon spheres through its extremely low density and high specific surface area, enabling more reflection, scattering and absorption of electromagnetic waves inside the material. Through the synergistic effect of the three, the anti-electromagnetic interference performance of the material is significantly improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0051] Figure 1 Schematic diagram of the result of the lightweight cable prepared according to the present invention.

[0052] In the figure: 100, conductor layer; 200, lightweight shielding layer; 300, wrapping layer; 400, composite sheath layer. Detailed implementation manners

[0053] The following will clearly and completely describe the technical solutions of the present invention in combination with the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0054] The hydroxyl silicone oil used in the present invention is purchased from Zhejiang Zhenghe Silicon Materials Co., Ltd., with the product number 207-35;

[0055] The nano calcium carbonate powder used in the present invention is purchased from Beijing Juguang Yingchuang Technology Co., Ltd., with the product number BM11268.

[0056] Example 1

[0057] This example is used to provide a preparation method of modified carbon spheres for lightweight and high-strength power cables based on composite materials, including the following steps:

[0058] Step ①, prepare carbon-coated nanospheres

[0059] Weigh: 100.0 g of nano calcium carbonate powder is dispersed in a hydrothermal reaction kettle containing 2000.0 mL of 0.5 M glucose solution. The stirring rate of the reaction kettle is 60 rpm. After stirring at room temperature for 5 min, the temperature of the hydrothermal reaction kettle is raised to 140 °C and kept for 6 h. After the reaction is completed, when the temperature of the reaction kettle is lowered to room temperature, the reaction solution is filtered to collect the filter cake. The filter cake is transferred to a drying oven at 60 °C for vacuum drying. After the filter cake reaches a constant weight, the filter cake is transferred to a tube furnace. After introducing nitrogen protection, the tube furnace is heated at a heating rate of 5 °C / min to 720 °C and kept for calcination for 5 h, and then naturally cooled to obtain carbon-coated nanospheres.

[0060] Step ②, prepare carbon-shell hollow spheres

[0061] Weigh: 200.0 g of carbon-coated nanospheres and 3000.0 mL of 49.0 wt% sulfuric acid were added to a reaction kettle. The stirring rate of the reaction kettle was 60 rpm. After stirring at room temperature for 10 min, 600.0 g of potassium permanganate was added to the reaction kettle. The temperature of the reaction kettle was raised to 40 °C and kept warm for 1 h. After the reaction was completed, after the temperature of the reaction kettle decreased to room temperature, a protective sodium hydroxide solution was added to the reaction kettle to adjust the reaction solution to be neutral. The reaction solution was filtered by suction to collect the filter cake, and the filter cake was washed 3 times with absolute ethanol and deionized water. The filter cake was transferred to a drying oven at 60 °C and vacuum dried until the filter cake reached a constant weight to obtain carbon shell hollow spheres.

[0062] Step ③, Preparation of modified carbon spheres

[0063] Weigh: 200.0 g of 3-isocyanatopropyltrimethoxysilane and 1000.0 mL of N,N-dimethylformamide were mixed to obtain a 3-isocyanatopropyltrimethoxysilane solution;

[0064] Weigh: 400.0 g of hollow carbon spheres and 3000.0 mL of N,N-dimethylformamide were added to a reaction kettle, and nitrogen protection was introduced. The stirring rate of the reaction kettle was 60 rpm. After stirring at room temperature for 5 min, 1000.0 mL of 3-isocyanatopropyltrimethoxysilane solution was added to the reaction kettle. The temperature of the reaction kettle was raised to 30 °C and kept warm for 30 min. After the reaction was completed, after the temperature of the reaction kettle decreased to room temperature, the reaction solution was filtered by suction to collect the filter cake, and the filter cake was washed 3 times with absolute ethanol. The filter cake was transferred to a drying oven at 60 °C and vacuum dried until the filter cake reached a constant weight to obtain modified carbon spheres.

[0065] Example 2

[0066] This example is used to provide a preparation method of modified carbon spheres for lightweight and high-strength power cables based on composite materials, including the following steps:

[0067] Step ①, Preparation of carbon-coated nanospheres

[0068] Weigh: 200.0 g of nano-calcium carbonate powder was dispersed in a hydrothermal reaction kettle containing 24 mL of 0.8 M glucose solution. The stirring rate of the reaction kettle was 80 rpm. After stirring at room temperature for 5 min, the temperature of the hydrothermal reaction kettle was raised to 140 °C and kept warm for 6 h. After the reaction was completed, after the temperature of the reaction kettle decreased to room temperature, the reaction solution was filtered by suction to collect the filter cake. The filter cake was transferred to a drying oven at 60 °C for vacuum drying. After the filter cake reached a constant weight, the filter cake was transferred to a tube furnace. After introducing nitrogen protection, the tube furnace was heated at a heating rate of 5 °C / min to 720 °C, kept warm and calcined for 5 h, and then naturally cooled to obtain carbon-coated nanospheres.

[0069] Step ②, Preparation of carbon shell hollow spheres

[0070] Weigh: 300.0 g of carbon-coated nanospheres and 3600.0 mL of 49.0 wt% sulfuric acid were added to a reaction kettle. The stirring rate of the reaction kettle was 80 rpm. After stirring at room temperature for 15 min, 800.0 g of potassium permanganate was added to the reaction kettle. The temperature of the reaction kettle was raised to 50 °C and kept for 2 h. After the reaction was completed, after the temperature of the reaction kettle was lowered to room temperature, a protective sodium hydroxide solution was added to the reaction kettle to adjust the reaction solution to be neutral. The reaction solution was filtered by suction to collect the filter cake, and the filter cake was washed 5 times with absolute ethanol and deionized water. The filter cake was transferred to a drying oven at 80 °C and vacuum dried until the filter cake reached a constant weight, and carbon shell hollow spheres were obtained.

[0071] Step ③, preparation of modified carbon spheres

[0072] Weigh: 300.0 g of 3-isocyanatopropyltrimethoxysilane and 1500.0 mL of N,N-dimethylformamide were mixed to obtain a 3-isocyanatopropyltrimethoxysilane solution;

[0073] Weigh: 500.0 g of hollow carbon spheres and 4000.0 mL of N,N-dimethylformamide were added to a reaction kettle, and nitrogen protection was introduced. The stirring rate of the reaction kettle was 80 rpm. After stirring at room temperature for 8 min, 1200.0 mL of the 3-isocyanatopropyltrimethoxysilane solution was added to the reaction kettle. The temperature of the reaction kettle was raised to 50 °C and kept for 40 min. After the reaction was completed, after the temperature of the reaction kettle was lowered to room temperature, the reaction solution was filtered by suction to collect the filter cake, and the filter cake was washed 5 times with absolute ethanol. The filter cake was transferred to a drying oven at 80 °C and vacuum dried until the filter cake reached a constant weight, and modified carbon spheres were obtained.

[0074] Example 3

[0075] This example is used to provide a preparation method of modified carbon spheres for a lightweight and high-strength power cable based on a composite material, including the following steps:

[0076] Step ①, preparation of carbon-coated nanospheres

[0077] Weigh: 150.0 g of nano-calcium carbonate powder was dispersed in a hydrothermal reaction kettle containing 2100.0 mL of 0.6 M glucose solution. The stirring rate of the reaction kettle was 70 rpm. After stirring at room temperature for 8 min, the temperature of the hydrothermal reaction kettle was raised to 150 °C and kept for 7 h. After the reaction was completed, after the temperature of the reaction kettle was lowered to room temperature, the reaction solution was filtered by suction to collect the filter cake. The filter cake was transferred to a drying oven at 70 °C for vacuum drying. After the filter cake reached a constant weight, the filter cake was transferred to a tube furnace. After introducing nitrogen protection, the tube furnace was heated at a heating rate of 5 °C / min to 720 °C and kept for 5 h of calcination, and then naturally cooled to obtain carbon-coated nanospheres.

[0078] Step ②, preparation of carbon shell hollow spheres

[0079] Weigh: 250.0 g of carbon-coated nanospheres and 3200.0 mL of 49.0 wt% sulfuric acid were added to the reaction kettle. The stirring rate of the reaction kettle was 70 rpm. After stirring at room temperature for 12 min, 700.0 g of potassium permanganate was added to the reaction kettle. The temperature of the reaction kettle was raised to 45 °C and kept warm for 2 h. After the reaction was completed, after the temperature of the reaction kettle was lowered to room temperature, a protective sodium hydroxide solution was added to the reaction kettle to adjust the reaction solution to be neutral. The reaction solution was filtered by suction to collect the filter cake, and the filter cake was washed 4 times with absolute ethanol and deionized water. The filter cake was transferred to a drying oven at 70 °C and vacuum dried until the filter cake reached a constant weight to obtain carbon shell hollow spheres.

[0080] Step ③, Prepare modified carbon spheres

[0081] Weigh: 250.0 g of 3-isocyanatopropyltrimethoxysilane and 1200.0 mL of N,N-dimethylformamide were mixed to obtain a 3-isocyanatopropyltrimethoxysilane solution;

[0082] Weigh: 450.0 g of hollow carbon spheres and 3600.0 mL of N,N-dimethylformamide were added to the reaction kettle, and nitrogen protection was introduced. The stirring rate of the reaction kettle was 70 rpm. After stirring at room temperature for 6 min, 1100.0 mL of the 3-isocyanatopropyltrimethoxysilane solution was added to the reaction kettle. The temperature of the reaction kettle was raised to 40 °C and kept warm for 35 min. After the reaction was completed, after the temperature of the reaction kettle was lowered to room temperature, the reaction solution was filtered by suction to collect the filter cake, and the filter cake was washed 4 times with absolute ethanol. The filter cake was transferred to a drying oven at 70 °C and vacuum dried until the filter cake reached a constant weight to obtain modified carbon spheres.

[0083] Example 4

[0084] This example is used to provide a preparation method of a composite aerogel for a lightweight and high-strength power cable based on a composite material, including the following steps:

[0085] Step ⑴, Prepare a composite solution

[0086] Weigh: 100.0 g of copper nitrate and 800.0 mL of ethylene glycol were mixed to obtain a copper source solution;

[0087] Weigh: 400.0 g of the modified carbon spheres prepared in Example 1, 700.0 g of tetrabutyl titanate and 6000.0 mL of deionized water were added to the reaction kettle. The stirring rate of the reaction kettle was 60 rpm. After stirring at room temperature for 10 min, 1000.0 mL of the copper source solution was added dropwise to the reaction kettle, and stirring was continued for 5 min to obtain a composite solution.

[0088] Step ⑵, Prepare a gel precursor

[0089] Weigh: Transfer 3000.0 mL of the composite solution into a hydrothermal reactor. Raise the temperature of the hydrothermal reactor to 160 °C and keep it at this temperature for 20 h. After the reaction is completed, wait for the temperature of the hydrothermal reactor to drop to room temperature, then transfer the material into a stainless-steel mold. After that, transfer the stainless-steel mold onto a copper column immersed in liquid nitrogen. Let it stand for 20 min, and then transfer the mold into a vacuum dryer. Set the temperature to 30 °C and the vacuum degree to 3 mBar, and conduct vacuum drying for 1 h to obtain the gel precursor.

[0090] Step (3), preparing the composite aerogel

[0091] Weigh: Transfer 1000.0 g of the gel precursor into a tubular furnace. After purging the tubular furnace with nitrogen, heat it up to 400 °C at a heating rate of 3 °C / min. Then, cut off the nitrogen supply and introduce a mixed gas of hydrogen and nitrogen with a volume ratio of 4 mL:95 mL into the tubular furnace. Keep it at this temperature for 30 min and then let it cool naturally to room temperature to obtain the composite aerogel.

[0092] Example 5

[0093] This example is used to provide a preparation method of a composite aerogel for a lightweight and high-strength power cable based on a composite material, which includes the following steps:

[0094] Step (1), preparing the composite solution

[0095] Weigh: Mix 200.0 g of copper nitrate and 1000.0 mL of ethylene glycol to obtain the copper source solution;

[0096] Weigh: Add 600.0 g of the modified carbon spheres prepared in Example 2, 800.0 g of tetrabutyl titanate, and 8000.0 mL of deionized water into a reaction kettle. The stirring rate of the reaction kettle is 80 rpm. After stirring at room temperature for 15 min, add 2000.0 mL of the copper source solution dropwise into the reaction kettle and continue stirring for 8 min to obtain the composite solution.

[0097] Step (2), preparing the gel precursor

[0098] Weigh: Transfer 3000.0 mL of the composite solution into a hydrothermal reactor. Raise the temperature of the hydrothermal reactor to 200 °C and keep it at this temperature for 28 h. After the reaction is completed, wait for the temperature of the hydrothermal reactor to drop to room temperature, then transfer the material into a stainless-steel mold. After that, transfer the stainless-steel mold onto a copper column immersed in liquid nitrogen. Let it stand for 30 min, and then transfer the mold into a vacuum dryer. Set the temperature to 50 °C and the vacuum degree to 5 mBar, and conduct vacuum drying for 2 h to obtain the gel precursor.

[0099] Step (3), preparing the composite aerogel

[0100] Weigh: Transfer 1000.0 g of the gel precursor into a tubular furnace. After purging the tubular furnace with nitrogen for protection, heat it up to 500 °C at a heating rate of 5 °C / min, then cut off the nitrogen, and introduce a mixed gas of hydrogen and nitrogen with a volume ratio of 5 mL:95 mL into the tubular furnace. Keep it at a constant temperature for 40 min, and then cool it naturally to room temperature to obtain the composite aerogel.

[0101] Example 6

[0102] This example is used to provide a preparation method of a composite aerogel for lightweight and high-strength power cables based on composite materials, including the following steps:

[0103] Step ⑴, Prepare the composite liquid

[0104] Weigh: Mix 150.0 g of copper nitrate and 900.0 mL of ethylene glycol to obtain the copper source solution;

[0105] Weigh: Add 500.0 g of the modified carbon spheres prepared in Example 3, 750.0 g of tetrabutyl titanate, and 7200.0 mL of deionized water into a reaction kettle. The stirring rate of the reaction kettle is 70 rpm. After stirring at room temperature for 12 min, add 1600.0 mL of the copper source solution dropwise into the reaction kettle, and continue stirring for 6 min to obtain the composite liquid.

[0106] Step ⑵, Prepare the gel precursor

[0107] Weigh: Transfer 3000.0 mL of the composite liquid into a hydrothermal reaction kettle. Raise the temperature of the hydrothermal reaction kettle to 180.0 °C and keep it at a constant temperature for 24 h. After the reaction is completed, wait for the temperature of the hydrothermal reaction kettle to drop to room temperature, then transfer the material into a stainless steel mold, and then transfer the stainless steel mold onto a copper column immersed in liquid nitrogen. After standing for 25 min, transfer the mold into a vacuum dryer, set the temperature to 40 °C and the vacuum degree to 4 mBar, and vacuum dry for 1 h to obtain the gel precursor.

[0108] Step ⑶, Prepare the composite aerogel

[0109] Weigh: Transfer 1000.0 of the gel precursor into a tubular furnace. After purging the tubular furnace with nitrogen for protection, heat it up to 450.0 °C at a heating rate of 4 °C / min, then cut off the nitrogen, and introduce a mixed gas of hydrogen and nitrogen with a volume ratio of 5 mL:95 mL into the tubular furnace. Keep it at a constant temperature for 35 min, and then cool it naturally to room temperature to obtain the composite aerogel.

[0110] Example 7

[0111] This example is used to provide a preparation method of lightweight polyurethane for lightweight and high-strength power cables based on composite materials, including the following steps:

[0112] Step Ⅰ, Prepare the modified polyurethane

[0113] Weigh: 300.0 g of isophthalic diisocyanate and 1000.0 mL of N,N-dimethylformamide are mixed to obtain an isophthalic diisocyanate solution;

[0114] Weigh: 800.0 g of hydroxyl silicone oil, 100.0 g of hydroquinone di(2-hydroxyethyl) ether, 4000.0 mL of N,N-dimethylformamide and 20.0 g of dibutyltin dilaurate are added to a reaction kettle. After purging with nitrogen, 1000.0 mL of the isophthalic diisocyanate solution is added to the reaction kettle. The temperature of the reaction kettle is raised to 50 °C and kept warm for 4 h. After the reaction is completed, purified water is added to the reaction kettle, and the temperature of the reaction kettle is raised to 120 °C. Vacuum distillation is carried out until no liquid is collected, and the modified polyurethane is obtained.

[0115] Step II. Preparation of lightweight polyurethane

[0116] Weigh: 300.0 g of 3-isocyanatopropyltrimethoxysilane and 1000.0 mL of N,N-dimethylformamide are mixed to obtain a 3-isocyanatopropyltrimethoxysilane solution;

[0117] Weigh: 800.0 g of the modified polyurethane and 4000.0 mL of N,N-dimethylformamide are added to a reaction kettle and stirred at a stirring rate of 60 rpm. After the temperature of the reaction kettle is raised to 40 °C, 1000.0 mL of the 3-isocyanatopropyltrimethoxysilane solution is added to the reaction kettle. After stirring at a constant temperature for 30 min, deionized water and sodium hydroxide powder are added to the reaction kettle. After stirring at a constant temperature for 5 min, 200.0 g of the modified carbon spheres prepared in Example 1 are added to the reaction kettle. After reacting at a constant temperature for 20 min, after the reaction kettle is cooled to room temperature, the reaction solution is added to a rotary evaporator with a water bath temperature of 80 °C. Vacuum distillation is carried out until no liquid is collected, and the lightweight polyurethane is obtained.

[0118] Example 8

[0119] This example is used to provide a preparation method of lightweight polyurethane for a lightweight high-strength power cable based on a composite material, including the following steps:

[0120] Step I. Preparation of modified polyurethane

[0121] Weigh: 400.0 g of isophthalic diisocyanate and 1500.0 mL of N,N-dimethylformamide are mixed to obtain an isophthalic diisocyanate solution;

[0122] Weigh: 1000.0 g of hydroxy silicone oil, 200.0 g of hydroquinone dihydroxyethyl ether, 6000.0 mL of N,N-dimethylformamide, and 50.0 g of dibutyltin dilaurate and add them to a reaction kettle. After introducing nitrogen for protection, add 1200.0 mL of isophthalic acid dimethyl isocyanate solution to the reaction kettle. Raise the temperature of the reaction kettle to 60 °C and keep the temperature for reaction for 2 h. After the reaction is completed, add purified water to the reaction kettle, raise the temperature of the reaction kettle to 140 °C, and distill under reduced pressure until no liquid is drawn out to obtain modified polyurethane.

[0123] Step II, preparation of lightweight polyurethane

[0124] Weigh: 400.0 g of 3-isocyanatopropyltrimethoxysilane and 1500.0 mL of N,N-dimethylformamide and mix them to obtain a 3-isocyanatopropyltrimethoxysilane solution;

[0125] Weigh: 1000.0 g of modified polyurethane and 5000.0 mL of N,N-dimethylformamide and add them to a reaction kettle for stirring. The stirring rate is 60 - 80 rpm. After raising the temperature of the reaction kettle to 60 °C, add 1500.0 mL of 3-isocyanatopropyltrimethoxysilane solution to the reaction kettle. After keeping the temperature and stirring for 40 min, add deionized water and sodium hydroxide powder to the reaction kettle. After keeping the temperature and stirring for 8 min, add 300.0 g of modified carbon spheres prepared in Example 2 to the reaction kettle, keep the temperature for reaction for 30 min. After the reaction is completed, wait for the reaction kettle to cool to room temperature, add the reaction solution to a rotary evaporator with a water bath temperature of 100 °C, and distill under reduced pressure until no liquid is drawn out to obtain lightweight polyurethane.

[0126] Example 9

[0127] This example is used to provide a preparation method of lightweight polyurethane for lightweight high-strength power cables based on composite materials, including the following steps:

[0128] Step I, preparation of modified polyurethane

[0129] Weigh: 350.0 g of isophthalic acid dimethyl isocyanate and 1200.0 mL of N,N-dimethylformamide and mix them to obtain an isophthalic acid dimethyl isocyanate solution;

[0130] Weigh: 900.0 g of hydroxy silicone oil, 160.0 g of hydroquinone dihydroxyethyl ether, 5000.0 mL of N,N-dimethylformamide, and 350.0 g of dibutyltin dilaurate and add them to a reaction kettle. After introducing nitrogen for protection, add 1100.0 mL of isophthalic acid dimethyl isocyanate solution to the reaction kettle. Raise the temperature of the reaction kettle to 54 °C and keep the temperature for reaction for 2 h. After the reaction is completed, add purified water to the reaction kettle, raise the temperature of the reaction kettle to 130 °C, and distill under reduced pressure until no liquid is drawn out to obtain modified polyurethane.

[0131] Step II: Prepare lightweight polyurethane

[0132] Weigh: 350.0 g of 3-isocyanatopropyltrimethoxysilane and 1200.0 mL of N,N-dimethylformamide are mixed to obtain a 3-isocyanatopropyltrimethoxysilane solution;

[0133] Weigh: 900.0 g of modified polyurethane and 4500.0 mL of N,N-dimethylformamide are added to a reaction kettle and stirred. The stirring rate is 70 rpm. After the temperature of the reaction kettle rises to 50 °C, 1200.0 mL of the 3-isocyanatopropyltrimethoxysilane solution is added to the reaction kettle. After heat-preserving and stirring for 35 min, deionized water and sodium hydroxide powder are added to the reaction kettle. After heat-preserving and stirring for 6 min, 250.0 g of the modified carbon spheres prepared in Example 3 are added to the reaction kettle. After heat-preserving and reacting for 24 min, after the reaction is completed and the reaction kettle is cooled to room temperature, the reaction solution is added to a rotary evaporator with a water bath temperature of 90 °C, and vacuum distillation is carried out until no liquid is drawn out to obtain lightweight polyurethane.

[0134] Example 10

[0135] This example is used to provide a preparation method of a lightweight and high-strength power cable based on composite materials, including the following steps:

[0136] Step 1: Prepare a lightweight shielding layer and a wrapping layer

[0137] After using the composite aerogel prepared in Example 4 to coat the surface of the conductor layer 100, a polyvinylidene fluoride wrapping tape is used to wrap around the outside of the composite aerogel to obtain a lightweight shielding layer 200 and a wrapping layer 300.

[0138] Step 2: Prepare a lightweight cable

[0139] Weigh: 7000.0 g of the lightweight polyurethane prepared in Example 7, 1000.0 g of hexabromocyclododecane, 500.0 g of dioctyl phthalate, 20.0 g of 2-hydroxy-4-octyloxybenzophenone, and 300.0 g of calcium stearate are added to a twin-screw extruder. The temperatures of the eight temperature zones of the twin-screw extruder from the feed port to the discharge port are 200 °C, 215 °C, 215 °C, 220 °C, 220 °C, 230 °C, 230 °C, and 240 °C in sequence. The main engine speed of the twin-screw extruder is 80 rpm, and the pressure is 100 bar. It is melt-extruded onto the surface of the wrapping layer 300 and naturally cooled to obtain a lightweight cable.

[0140] Example 11

[0141] This example is used to provide a preparation method of a lightweight and high-strength power cable based on composite materials, including the following steps:

[0142] Step 1: Prepare the lightweight shielding layer and the wrapping layer

[0143] After coating the surface of the conductor layer 100 with the composite aerogel prepared in Example 5, wrap the outside of the composite aerogel with a polyvinylidene fluoride wrapping tape to obtain the lightweight shielding layer 200 and the wrapping layer 300.

[0144] Step 2: Prepare the lightweight cable

[0145] Weigh: 8500.0 g of the lightweight polyurethane prepared in Example 8, 1500.0 g of hexabromocyclododecane, 800.0 g of dioctyl phthalate, 50.0 g of 2-hydroxy-4-octyloxybenzophenone, and 500.0 g of calcium stearate and add them to a twin-screw extruder. The temperatures of the eight temperature zones of the twin-screw extruder from the feed port to the discharge port are 200 °C, 215 °C, 215 °C, 220 °C, 220 °C, 230 °C, 230 °C, and 240 °C in sequence. The main machine speed of the twin-screw extruder is 120 rpm, the pressure is 150 bar, melt extrude it onto the surface of the wrapping layer 300, and naturally cool to obtain the lightweight cable.

[0146] Example 12

[0147] This example is used to provide a preparation method of a lightweight and high-strength power cable based on composite materials, including the following steps:

[0148] Step 1: Prepare the lightweight shielding layer and the wrapping layer

[0149] After coating the surface of the conductor layer 100 with the composite aerogel prepared in Example 6, wrap the outside of the composite aerogel with a polyvinylidene fluoride wrapping tape to obtain the lightweight shielding layer 200 and the wrapping layer 300.

[0150] Step 2: Prepare the lightweight cable

[0151] Weigh: 8100.0 g of the lightweight polyurethane prepared in Example 9, 1200.0 g of hexabromocyclododecane, 720.0 g of dioctyl phthalate, 35.0 g of 2-hydroxy-4-octyloxybenzophenone, and 400.0 g of calcium stearate and add them to a twin-screw extruder. The temperatures of the eight temperature zones of the twin-screw extruder from the feed port to the discharge port are 200 °C, 215 °C, 215 °C, 220 °C, 220 °C, 230 °C, 230 °C, and 240 °C in sequence. The main machine speed of the twin-screw extruder is 100 rpm, the pressure is 120 bar, melt extrude it onto the surface of the wrapping layer 300, and naturally cool to obtain the lightweight cable.

[0152] Comparative Example 1

[0153] The difference between this comparative example and Example 12 is that in the preparation process of the light polyurethane used in Step 1, Step II is cancelled, and the modified polyurethane is used to replace the light polyurethane in equal amount.

[0154] Comparative Example 2

[0155] The difference between this comparative example and Example 12 is that in the preparation process of the composite aerogel used in Step 2, the use of modified carbon spheres is cancelled in Step (1).

[0156] Comparative Example 3

[0157] The difference between this comparative example and Example 12 is that in the preparation process of the composite aerogel used in Step 2, the use of copper source solution is cancelled in Step (1).

[0158] Performance test:

[0159] Refer to the standard XF 306.1-2007 "Flame Retardant and Fire Resistant Cables - Classification and Requirements for Flame Retardant and Fire Resistant Cables with Plastic Insulation - Part 1: Flame Retardant Cables" to test the tensile strength of the light cables prepared in Examples 10 - 12 and Comparative Examples 1 - 3;

[0160] Refer to the standard GB / T 32511-2016 "General Technical Requirements for Electromagnetic Shielding Plastics" to test the anti-electromagnetic interference efficiency of the light cables prepared in Examples 10 - 12 and Comparative Examples 1 - 3;

[0161] Refer to the standard XF 306.1-2007 "Flame Retardant and Fire Resistant Cables - Classification and Requirements for Flame Retardant and Fire Resistant Cables with Plastic Insulation - Part 1: Flame Retardant Cables" to test the flame retardant grade of the light cables prepared in Examples 10 - 12 and Comparative Examples 1 - 3;

[0162] Refer to the standard GB / T 1033.2-2010 "Plastics - Determination of the Density of Non-Cellular Plastics - Part 2: Density Gradient Column Method" to test the density of the composite sheath layers prepared in Examples 10 - 12 and Comparative Examples 1 - 3;

[0163] Refer to the standard GB / T 1033.2-2010 "Plastics - Determination of the Density of Non-Cellular Plastics - Part 2: Density Gradient Column Method" to determine the density of the composite aerogels used in Examples 10 - 12 and Comparative Examples 1 - 3. The specific data are shown in Table 1.

[0164] Table 1 - Performance Detection Data Table of Each Specimen

[0165] Project Group Example 10 Example 11 Example 12 Comparative Example 1 Comparative Example 2 Comparative Example 3 Tensile Strength / MPa 25.3 26.1 27.2 13.2 21.3 20.2 Electromagnetic Interference Resistance Efficiency / level SE-1 SE-1 SE-1 SE-2 SE-2 SE-2 Flame Retardant Rating / level ⅠA ⅠA ⅠA ⅠB ⅠC ⅠB <![CDATA[Composite sheath tube density / g·cm -3 > 0.2785 0.2732 0.2691 0.7215 0.2815 0.2824 <![CDATA[Composite aerogel density / g·cm -3 > 0.25 0.24 0.24 0.26 0.48 0.22

[0166] Data analysis:

[0167] Comparative analysis of the data in Table 1 reveals that the tensile strength of the lightweight cable prepared by the present invention is 27.2 MPa, the anti-electromagnetic interference efficacy is SE-1 level, and the flame retardant rating is IA. The density of the composite sheath layer is 0.2691 g·cm -3 and the density of the composite aerogel is 0.24 g·cm -3 , and the performance test data of each item are better than those of the comparative example;

[0168] It shows that the present invention prepares carbon-coated nanospheres by using nano-calcium carbonate powder as a template, and while removing calcium carbonate in an acidic potassium permanganate solution, oxidizes the carbon layer to obtain carbon shell hollow spheres, modifies the surface with a highly hydrolyzable silane coupling agent to obtain modified carbon spheres. The modified carbon spheres are used as filling materials and react with tetrabutyl titanate by hydrothermal hydrolysis to obtain a gel precursor. After loading and reducing copper nitrate on it, a composite aerogel is obtained. The porous structure of the composite aerogel and the hollow carbon spheres cooperate synergistically to significantly reduce the density of the material, significantly improving the lightweight performance of the material. And in the process of preparing lightweight polyurethane, the modified carbon spheres are used as filling materials and chain extenders, hybridizing polyurethane segments and reducing the density of polyurethane materials. The complex three-dimensional spatial structure of polyurethane segments and the spherical buffer structure of modified carbon spheres significantly enhance the cantilever beam impact strength of the lightweight cable, significantly improving the strength of the cable material;

[0169] It shows that the copper particles in the composite aerogel structure prepared by the present invention, due to their good thermal conductivity, help to evenly disperse heat, prevent local overheating, and indirectly enhance the thermal stability and high-temperature resistance of the material. Titanium dioxide, as an inorganic compound with high thermal stability, can form a protective ceramic layer at high temperatures, effectively preventing the spread of flames and enhancing the overall flame retardant effect. The hollow carbon spheres in the composite aerogel structure and lightweight polyurethane utilize their porous structure and low-density characteristics to form a carbonized layer and enhance the thermal insulation effect, prevent the spread of flames, and help reduce heat conduction. And with their low thermal conductivity and high specific surface area, they provide additional thermal insulation protection, optimizing the synergistic effect of other components, thereby enhancing the flame retardant ability of the overall material. Through the synergistic effect of these three, the cable can effectively delay the combustion process under high-temperature and flame exposure conditions, prevent the spread of flames, and provide excellent flame retardant performance.

[0170] It is noted that the composite aerogel prepared in the present invention is used as a filling material for a lightweight shielding layer. The copper particles loaded in its structure absorb and reflect electromagnetic waves through their excellent electrical conductivity. The titanium dioxide structure utilizes its semiconductor properties and strong photoelectric effect to enhance the absorption and reflection effects of high-frequency electromagnetic waves, and provides a better dispersion environment for the copper particles, thereby improving the overall shielding ability. The composite aerogel structure and the hollow carbon spheres in the lightweight polyurethane increase the reflection and scattering effects of the material and reduce the density by virtue of their porous structures, lightweight characteristics, and electrical conductivity, making the material more balanced and efficient in anti-electromagnetic interference. In addition, as a carrier, the aerogel matrix optimizes the cooperation among the copper particles, titanium dioxide, and hollow carbon spheres through its extremely low density and high specific surface area, enabling more reflection, scattering, and absorption of electromagnetic waves inside the material. Through the synergistic effect of the three, the anti-electromagnetic interference performance of the material is significantly improved.

[0171] The preferred embodiments of the present invention disclosed above are only used to help illustrate the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the present invention to only the specific implementation manners. Obviously, many modifications and variations can be made according to the content of this specification. These embodiments are selected and specifically described in this specification to better explain the principle and practical application of the present invention, so that those skilled in the relevant technical field can well understand and utilize the present invention. The present invention is only limited by the claims and their full scope and equivalents.

Claims

1. A lightweight and high-strength power cable based on composite materials, characterized in that: It comprises a conductor layer (100), a lightweight shielding layer (200), a wrapping layer (300) and a composite sheath layer (400) which are arranged in sequence from the inside to the outside; The conductor layer (100) is composed of a plurality of copper wires twisted together and coated with polyvinylidene fluoride; the wrapping layer (300) is obtained by wrapping a polyvinylidene fluoride wrapping tape around the outside of the composite aerogel; and the composite sheath layer (400) is composed of a composite cable material; The lightweight shielding layer (200) is obtained by coating the conductor layer (100) with a composite aerogel and fixing it with a wrapping tape; the composite sheath layer (400) is obtained by melting and extruding a composite cable material onto the surface of the wrapping layer (300) and shaping it, wherein the composite cable material is a mixture of lightweight polyurethane, flame retardant, plasticizer, ultraviolet absorber and lubricant in a mass ratio of 70-85g:10-15g:5-8g:0.2-0.5g:3-5g; The preparation method of the composite aerogel comprises the following steps: A1. Add modified carbon spheres, tetrabutyl titanate and deionized water into a reactor, stir at room temperature for 10-15 minutes, then dropwise add copper source solution into the reactor, and continue stirring for 5-8 minutes to obtain a composite solution; A2, transferring the composite liquid to a hydrothermal reactor, raising the temperature of the hydrothermal reactor to 160-200°C, keeping the temperature for 20-28h, and post-treating to obtain a gel precursor; A3, transferring the gel precursor to a tubular furnace, calcining and reducing to obtain a composite aerogel; The preparation method of the modified carbon spheres comprises the following steps: B1. Disperse nano-calcium carbonate powder in a hydrothermal reactor filled with a carbon source solution, stir for 5-8 minutes at room temperature, raise the temperature of the hydrothermal reactor to 140-160°C, keep the reaction for 6-8 hours, and post-treat to obtain carbon-coated nanospheres; B2, adding carbon-coated nanospheres and 49.0wt% sulfuric acid into a reactor, stirring at room temperature for 10-15min, adding potassium permanganate into the reactor, raising the temperature of the reactor to 40-50°C, keeping the temperature for 1-2h, and post-treating to obtain carbon shell hollow spheres; B3. Add hollow carbon spheres and N,N-dimethylformamide into a reactor, introduce nitrogen protection, stir at room temperature for 5-8 minutes, add 3-isocyanatepropyltrimethoxysilane solution into the reactor, increase the temperature of the reactor to 30-50°C, keep warm for 30-40 minutes, and post-treat to obtain modified carbon spheres.

2. The lightweight and high-strength power cable based on composite materials according to claim 1, characterized in that: In step A1, the amount ratio of modified carbon spheres, tetrabutyl titanate, deionized water and copper source solution is 4-6g:7-8g:60-80mL:10-20mL, and the copper source solution is obtained by mixing copper nitrate and ethylene glycol in an amount ratio of 1-2g:8-10mL; in step A3, the calcination reduction operation is as follows: after nitrogen protection is introduced into the tubular furnace, the temperature is increased to 400-500°C at a heating rate of 3-5°C / min, the nitrogen is disconnected, and a mixed gas of hydrogen and nitrogen in a volume ratio of 4-5mL:95mL is introduced into the tubular furnace, and the mixture is kept warm for 30-40min, and naturally cooled to room temperature to obtain a composite aerogel.

3. The lightweight and high-strength power cable based on composite materials according to claim 1, characterized in that: In step B1, the dosage ratio of nano calcium carbonate powder and carbon source solution is 1-2g:20-24mL, and the carbon source solution is a glucose solution with a concentration of 0.5-0.8M; in step B2, the dosage ratio of carbon-coated nanospheres, 49.0wt% sulfuric acid and potassium permanganate is 2-3g:30-36mL:6-8g.

4. The lightweight and high-strength power cable based on composite materials according to claim 1, characterized in that: In step B3, the amount ratio of the hollow carbon sphere, N,N-dimethylformamide and 3-isocyanate propyltrimethoxysilane solution is 4-5g:30-40mL:10-12mL, and the 3-isocyanate propyltrimethoxysilane solution is obtained by mixing 3-isocyanate propyltrimethoxysilane and N,N-dimethylformamide in an amount ratio of 2-3g:10-15mL.

5. The lightweight and high-strength power cable based on composite materials according to claim 1, characterized in that: The preparation method of the lightweight polyurethane comprises the following steps: C1. Add hydroxy silicone oil, hydroquinone dihydroxyethyl ether, N,N-dimethylformamide and dibutyltin dilaurate into a reactor, introduce nitrogen protection, add meta-xylyl diisocyanate solution into the reactor, increase the temperature of the reactor to 50-60°C, keep the reaction temperature for 1-2h, and post-treat to obtain modified polyurethane; C2. Add modified polyurethane and N,N-dimethylformamide into a reactor and stir. After the temperature of the reactor rises to 40-60°C, add 3-isocyanatepropyltrimethoxysilane solution into the reactor. After stirring for 30-40 minutes, add deionized water and sodium hydroxide powder into the reactor. After stirring for 5-8 minutes, add modified carbon balls into the reactor. Keep warm for 20-30 minutes, and obtain lightweight polyurethane by post-treatment.

6. The lightweight and high-strength power cable based on composite materials according to claim 5, characterized in that: In step C1, the amount ratio of hydroxy silicone oil, dihydroxyethyl hydroquinone, N,N-dimethylformamide, dibutyltin dilaurate and meta-phenylenedimethyl isocyanate solution is 8-10g:1-2g:40-60mL:0.2-0.5g:10-12mL; in step C2, the amount ratio of modified polyurethane, N,N-dimethylformamide, 3-isocyanatepropyltrimethoxysilane solution and modified carbon sphere is 8-10g:40-50mL:10-15mL:2-3g.

7. Application of lightweight and high-strength power cables based on composite materials, characterized in that: The lightweight and high-strength power cable based on composite materials described in any one of claims 1 to 6 is applied to aerospace, high-altitude cable construction, ship power supply and marine engineering.

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