Lightweight aluminum alloy control cable based on graphene composite shielding layer

Abstract

The present application relates to the technical field of aluminum alloy cable, in particular to a light-weight aluminum alloy control cable based on a graphene composite shielding layer; comprising a conductor, an insulating layer coated on the conductor, a shielding layer coated on the insulating layer, and a sheath layer coated on the shielding layer; the shielding layer is made of the following raw materials in weight fractions: 65-75 parts of acrylate-pyrrole copolymer, 10-15 parts of modified graphene particles, 8-12 parts of carbon black, 1-3 parts of silane coupling agent, 2-5 parts of dioctyl phthalate, and 1-2 parts of zinc stearate. The control cable uses acrylate-pyrrole copolymer as the main material of the shielding layer, and improves the conductivity of the shielding layer by using modified graphene particles, so that the shielding layer can effectively protect the conductor and avoid external interference. Moreover, the modified graphene has good compatibility with the acrylate-pyrrole copolymer, which can effectively ensure the mechanical properties of the shielding layer and avoid cracking during use.

Description

Technical Field

[0001] This invention relates to the field of aluminum alloy cable technology, specifically to a lightweight aluminum alloy control cable based on a graphene composite shielding layer. Background Technology

[0002] Control cables are cables specifically designed for transmitting control, measurement, and signal commands, and are widely used in industrial automation, process control, power systems, and mechanical equipment. Because industrial environments are filled with various interference sources, such as high-power motors, frequency converters, wireless equipment, and high-voltage transmission lines, which generate strong electromagnetic fields, control cables need to have excellent electromagnetic shielding properties to resist interference from these fields and ensure the accuracy of transmitted control signals.

[0003] Existing cable shielding layers mainly include wrapped shielding layers, braided shielding layers, and polymer shielding layers. Wrapped shielding layers are made by spirally wrapping metal strips around the cable core. However, due to gaps between the metal strips, the metal strips are prone to cracking, loosening, or developing gaps when the cable is frequently bent, moved, or subjected to vibration, thus losing their shielding function. Braided shielding layers require metal wires to be woven into a mesh and covered on the cable core. Although this provides better shielding performance, the manufacturing cost is high. While polymer shielding layers have good toughness and high coverage, the existing polymer shielding layers have poor conductivity, resulting in generally poor shielding performance. Summary of the Invention

[0004] To address the aforementioned problems, this invention provides a lightweight aluminum alloy control cable based on a graphene composite shielding layer.

[0005] The technical solution of the present invention is: a lightweight aluminum alloy control cable based on a graphene composite shielding layer, comprising a conductor, an insulation layer covering the conductor, a shielding layer covering the insulation layer, and a sheath layer covering the shielding layer; the shielding layer is made of the following raw materials by weight: 65-75 parts of acrylate-pyrrole copolymer, 10-15 parts of modified graphene particles, 8-12 parts of carbon black, 1-3 parts of silane coupling agent, 2-5 parts of dioctyl phthalate, and 1-2 parts of zinc stearate.

[0006] Note: The above control cable uses acrylate-pyrrole copolymer as the main material of the shielding layer, and the conductivity of the shielding layer is improved by adding modified graphene particles, so that the shielding layer can effectively protect the conductor and avoid external interference. In addition, the modified graphene and acrylate-pyrrole copolymer have good compatibility, which can effectively ensure the mechanical properties of the shielding layer and prevent the shielding layer from cracking during use.

[0007] Furthermore, the silane coupling agent is KH-550 or KH-560.

[0008] Note: The above-mentioned silane coupling agent can improve the compatibility between carbon black and acrylate-pyrrole copolymer, ensuring that carbon black is uniformly dispersed in acrylate-pyrrole copolymer.

[0009] Furthermore, the preparation method of the modified graphene particles includes the following steps: 1) Place graphene oxide powder in deionized water and ultrasonically disperse for 15-20 minutes to obtain graphene oxide dispersion; wherein the mass ratio of graphene oxide powder to deionized water is 1:10-12. 2) Add an activator to the graphene oxide dispersion, and then stir at room temperature for 0.5-1 hour under an inert gas atmosphere. After stirring, filter and dry to obtain activated graphene. The amount of activator added is 2-4% of the mass of the graphene oxide dispersion. 3) Add activated graphene powder to an ethanol solution with a mass concentration of 60-80%, and disperse it ultrasonically for 15-20 minutes to obtain an activated graphene dispersion; wherein the mass ratio of activated graphene powder to ethanol solution is 1:6-8. 4) At room temperature, the activated graphene dispersion is added to a reactor, and then inert gas is introduced into the reactor until the pressure inside the reactor reaches 0.25~0.3 MPa. Pressurization is then stopped, and diethylenetriamine is added to the reactor. The reactor is then heated, and pressure is released during the heating process. The heating rate is 4~5℃ / min, and the pressure release rate is 0.01~0.02 MPa / min, until the temperature inside the reactor reaches 60~70℃. Pressure release is then stopped, and the temperature is maintained. A metal salt solution is then added to the reactor, and inert gas is introduced again during the heat maintenance process until the pressure inside the reactor reaches 0.3~0.4 MPa. The mixture is then maintained at this temperature and pressure for 20~24 hours to obtain the first mixture. The amount of diethylenetriamine added is 3~4% of the initial mass of the activated graphene dispersion, and the amount of the metal salt solution added is 1~3% of the initial mass of the activated graphene dispersion. 5) Filter the first mixture to obtain solid particles, wash and dry the solid particles to obtain modified graphene particles.

[0010] Explanation: The above method connects graphene to the amino groups on diethylenetriamine and chelates copper ions to improve the conductivity of modified graphene particles. At the same time, the amino groups of diethylenetriamine can form covalent bonds with the polymer chains of acrylate-pyrrole copolymer to improve the compatibility between modified graphene particles and acrylate-pyrrole copolymer.

[0011] Furthermore, the activator is hydroxysuccinimide or 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide.

[0012] Note: The above activator can activate the carboxyl groups on the surface of graphene oxide to increase the loading rate of diethylenetriamine on the graphene surface.

[0013] Furthermore, the preparation method of the acrylate-pyrrole copolymer includes the following steps: 1) Add pyrrole to dimethylformamide and stir until the pyrrole is completely dissolved to obtain a pyrrole solution. Then, add ammonium persulfate aqueous solution dropwise to the pyrrole solution and continue stirring for 15-20 minutes to obtain a second mixture. The mass ratio of pyrrole, ammonium persulfate aqueous solution and dimethylformamide is 1:0.1-0.2:8-10. 2) Add acrylate to the second mixture, stir for 10-15 min, then add azobisisobutyronitrile (AIBN), and continue stirring at 65-70℃ for 45-60 min to obtain the reaction solution; wherein, the amount of acrylate added accounts for 10-15% of the total mass of the second mixture, and the amount of AIBN added accounts for 1-2% of the total mass of the second mixture; 3) Add the reaction solution to 5 to 7 times its mass of anhydrous ethanol, then centrifuge to obtain a precipitate. Wash and dry the precipitate to obtain an acrylate-pyrrole copolymer.

[0014] Note: The above method copolymerizes acrylate and pyrrole. Pyrrole provides conductivity to the copolymer, ensuring the electromagnetic shielding performance of the shielding layer, while acrylate provides good flexibility and film-forming properties to ensure that the remaining raw materials of the shielding layer can be uniformly dispersed.

[0015] Furthermore, the mass concentration of the ammonium persulfate aqueous solution is 4-8%.

[0016] Note: The above-mentioned concentration of ammonium persulfate aqueous solution can initiate the prepolymerization of pyrrole to form polypyrrole oligomers and ensure the length of the polypyrrole chains.

[0017] Furthermore, the precipitate is dried by drying at a vacuum of 0.08~0.1MPa and a temperature of 45~60℃ for 20~30 minutes.

[0018] Note: The above drying parameters can effectively remove moisture from the acrylate-pyrrole copolymer and reduce impurities in the acrylate-pyrrole copolymer.

[0019] Furthermore, the method for preparing the control cable includes the following steps: S1. After drawing the aluminum alloy rod, aluminum alloy monofilaments are obtained. Multiple aluminum alloy monofilaments are twisted together and then annealed to obtain a conductor. S2. The cable insulation material is added into the screw extruder and melted at 160~180℃. It is then extruded onto the conductor through the extruder to form an insulation layer. After cooling, the conductor covered with the insulation layer is obtained. The thickness of the insulation layer is 0.6~1.5mm. S3. According to the stated weight proportions, the shielding layer raw material is added to a mixer and mixed for 30-40 minutes to obtain a mixture. The mixture is then added to a screw extruder and melt-blended at 175-195°C. Subsequently, it is extruded through an extruder onto a conductor with an insulating layer to form a shielding layer. After cooling, a conductor with a shielding layer is obtained. The thickness of the shielding layer is 0.5-1.0 mm. S4. The cable sheath material is added into the screw extruder and melted at 170~180℃. It is then extruded through the extruder onto the conductor covering the shielding layer to form a sheath layer. After cooling, the control cable is obtained. The thickness of the sheath layer is 1.5~2.0mm.

[0020] Note: The above preparation method uses aluminum alloy monofilaments to form a conductor, ensuring that the cable is lightweight while having good conductivity. Then, insulation, shielding and sheathing layers are wrapped around the conductor through multiple extrusions to protect the conductor. The shielding layer can effectively block external electromagnetic interference and ensure the reliability of signal transmission within the cable.

[0021] The beneficial effects of this invention are: (1) The control cable of the present invention uses acrylate-pyrrole copolymer as the main material of the shielding layer, and improves the conductivity of the shielding layer by modifying graphene particles, so that the shielding layer can effectively protect the conductor and avoid external interference. Furthermore, the modified graphene and acrylate-pyrrole copolymer have good compatibility, which can effectively ensure the mechanical properties of the shielding layer and prevent the shielding layer from cracking during use.

[0022] (2) The present invention connects graphene with the amino group on diethylenetriamine and chelates copper ions to improve the conductivity of modified graphene particles. At the same time, the amino group of diethylenetriamine can form covalent bonds with the polymer chain of acrylate-pyrrole copolymer to improve the compatibility between modified graphene particles and acrylate-pyrrole copolymer.

[0023] (3) The preparation method of the present invention uses aluminum alloy monofilaments to form a conductor, which ensures that the cable is lightweight while having good conductivity. Then, insulation layer, shielding layer and sheath layer are wrapped on the conductor by multiple extrusions to protect the conductor. The shielding layer can effectively block external electromagnetic interference and ensure the reliability of signal transmission in the cable. Detailed Implementation

[0024] To further illustrate the methods and effects of this invention, the technical solution of this invention will be clearly and completely described below in conjunction with experiments.

[0025] Example 1: A lightweight aluminum alloy control cable based on a graphene composite shielding layer, comprising a conductor, an insulation layer covering the conductor, a shielding layer covering the insulation layer, and a sheathing layer covering the shielding layer; the shielding layer, by weight, is made of the following raw materials: 70 parts acrylate-pyrrole copolymer, 12 parts modified graphene particles, 10 parts carbon black, 2 parts silane coupling agent, 4 parts dioctyl phthalate, and 1.5 parts zinc stearate; the silane coupling agent is KH-550; the carbon black is acetylene black; The preparation method of modified graphene particles includes the following steps: 1) Place graphene oxide powder in deionized water and ultrasonically disperse for 18 min to obtain graphene oxide dispersion; wherein, the mass ratio of graphene oxide powder to deionized water is 1:11; the sheet diameter of graphene oxide powder is 1~20μm. 2) An activator was added to the graphene oxide dispersion, and then stirred at room temperature for 0.8 h under an inert gas atmosphere. After stirring, the mixture was filtered and dried to obtain activated graphene. The activator was hydroxysuccinimide, and the amount of activator added accounted for 3% of the mass of the graphene oxide dispersion. 3) Add activated graphene powder to a 70% ethanol solution and ultrasonically disperse for 18 min to obtain an activated graphene dispersion; wherein the mass ratio of activated graphene powder to ethanol solution is 1:7. 4) At room temperature, the activated graphene dispersion was added to the reactor, and then inert gas was introduced into the reactor until the pressure inside the reactor reached 0.28 MPa. Pressurization was then stopped, and diethylenetriamine was added to the reactor. The reactor was then heated, and pressure was released during the heating process. The heating rate was 4.5℃ / min, and the pressure release rate was 0.015 MPa / min, until the temperature inside the reactor reached 65℃. Pressure release was then stopped, and the reactor was kept at this temperature. A 9% (w / w) copper sulfate aqueous solution was then added to the reactor, and inert gas was introduced again during the heat preservation process until the pressure inside the reactor reached 0.35 MPa. The reactor was then kept at this temperature and pressure for 22 hours to obtain the first mixture. The amount of diethylenetriamine added accounted for 3.5% of the initial mass of the activated graphene dispersion, and the amount of copper sulfate aqueous solution added accounted for 2% of the initial mass of the activated graphene dispersion. 5) Filter the first mixture to obtain solid particles, wash and dry the solid particles to obtain modified graphene particles; The preparation method of acrylate-pyrrole copolymer includes the following steps: 1) Add pyrrole to dimethylformamide and stir until the pyrrole is completely dissolved to obtain a pyrrole solution. Then, add ammonium persulfate aqueous solution dropwise to the pyrrole solution and continue stirring for 18 minutes to obtain a second mixture. The mass ratio of pyrrole, ammonium persulfate aqueous solution and dimethylformamide is 1:0.15:9; the mass concentration of ammonium persulfate aqueous solution is 6%. 2) Add acrylate to the second mixture, stir for 13 min, then add azobisisobutyronitrile (AIBN), and continue stirring at 68°C for 55 min to obtain the reaction solution; wherein, the amount of acrylate added accounts for 12% of the total mass of the second mixture, and the amount of AIBN added accounts for 1.5% of the total mass of the second mixture; 3) Add the reaction solution to 6 times its mass of anhydrous ethanol, then centrifuge to obtain a precipitate. Wash and dry the precipitate to obtain the acrylate-pyrrole copolymer. The precipitate is dried at 0.09 MPa vacuum and 55°C for 25 min. The method for preparing the control cable includes the following steps: S1. After drawing the aluminum alloy rod, a 1mm diameter aluminum alloy single wire is obtained. Nineteen aluminum alloy single wires are concentrically twisted together and then annealed to obtain a conductor. The annealing method is to hold at 340℃ for 6 hours and then furnace cool to room temperature. S2. The cable insulation material is added into the screw extruder, melted at 170°C, and then extruded onto the conductor through the extruder to form an insulation layer. After cooling, the conductor with the insulation layer is obtained. The cable insulation material is commercially available polyethylene cable material with an insulation layer thickness of 1.2 mm. S3. According to the stated weight proportions, the shielding layer raw material is added to a mixer and mixed for 35 minutes to obtain a mixture. The mixture is then added to a screw extruder and melt-blended at 185°C. Subsequently, it is extruded through an extruder onto a conductor with an insulating layer to form a shielding layer. After cooling, a conductor with a shielding layer is obtained. The shielding layer thickness is 0.8 mm. S4. The cable sheath material is added into the screw extruder and melted at 175°C. It is then extruded through the extruder onto the conductor covering the shielding layer to form a sheath layer. After cooling, the control cable is obtained. The cable sheath material is commercially available polyvinyl chloride cable material with a sheath layer thickness of 1.8mm.

[0026] Example 2: This example is basically the same as Example 1, except that it includes a conductor, an insulating layer covering the conductor, a shielding layer covering the insulating layer, and a sheath layer covering the shielding layer; the shielding layer is made of the following raw materials by weight: 65 parts of acrylate-pyrrole copolymer, 10 parts of modified graphene particles, 8 parts of carbon black, 1 part of silane coupling agent, 2 parts of dioctyl phthalate, and 1 part of zinc stearate.

[0027] Example 3: This example is basically the same as Example 1, except that it includes a conductor, an insulating layer covering the conductor, a shielding layer covering the insulating layer, and a sheath layer covering the shielding layer; the shielding layer is made of the following raw materials by weight: 75 parts of acrylate-pyrrole copolymer, 15 parts of modified graphene particles, 12 parts of carbon black, 3 parts of silane coupling agent, 5 parts of dioctyl phthalate, and 2 parts of zinc stearate.

[0028] Example 4: This example is basically the same as Example 1, except that the amount of activator added accounts for 2% of the mass of the graphene oxide dispersion.

[0029] Example 5: This example is basically the same as Example 1, except that the amount of activator added accounts for 4% of the mass of the graphene oxide dispersion.

[0030] Example 6: This example is basically the same as Example 1, except that an inert gas is introduced into the reactor until the pressure inside the reactor reaches 0.25 MPa, then the pressurization is stopped, and diethylenetriamine is added into the reactor.

[0031] Example 7: This example is basically the same as Example 1, except that an inert gas is introduced into the reactor until the pressure inside the reactor reaches 0.3 MPa, then the pressurization is stopped, and diethylenetriamine is added into the reactor.

[0032] Example 8: This example is basically the same as Example 1, except that the amount of diethylenetriamine added accounts for 3% of the initial mass of the activated graphene dispersion.

[0033] Example 9: This example is basically the same as Example 1, except that the amount of diethylenetriamine added accounts for 4% of the initial mass of the activated graphene dispersion.

[0034] Example 10: This example is basically the same as Example 1, except that the heating rate inside the reactor during the heating process is 4℃ / min and the depressurization rate is 0.01MPa / min.

[0035] Example 11: This example is basically the same as Example 1, except that the heating rate inside the reactor during the heating process is 5℃ / min and the depressurization rate is 0.02MPa / min.

[0036] Example 12: This example is basically the same as Example 1, except that when the temperature inside the reactor reaches 60°C, the pressure is released and the temperature is maintained. Then, a 9% copper sulfate aqueous solution is added to the reactor.

[0037] Example 13: This example is basically the same as Example 1, except that when the temperature inside the reactor reaches 70°C, the pressure is released and the temperature is maintained. Then, a 9% copper sulfate aqueous solution is added to the reactor.

[0038] Example 14: This example is basically the same as Example 1, except that the amount of copper sulfate aqueous solution added accounts for 1% of the initial mass of the activated graphene dispersion.

[0039] Example 15: This example is basically the same as Example 1, except that the amount of copper sulfate aqueous solution added accounts for 3% of the initial mass of the activated graphene dispersion.

[0040] Example 16: This example is basically the same as Example 1, except that inert gas is introduced into the reactor again during the heat preservation process until the pressure inside the reactor reaches 0.3 MPa, and the heat preservation and pressure preservation lasts for 22 hours.

[0041] Example 17: This example is basically the same as Example 1, except that inert gas is introduced into the reactor again during the heat preservation process until the pressure inside the reactor reaches 0.4 MPa, and the heat preservation and pressure preservation lasts for 22 hours.

[0042] Example 18: This example is basically the same as Example 1, except that the mass ratio of pyrrole, ammonium persulfate aqueous solution and dimethylformamide is 1:0.1:8.

[0043] Example 19: This example is basically the same as Example 1, except that the mass ratio of pyrrole, ammonium persulfate aqueous solution and dimethylformamide is 1:0.2:10.

[0044] Example 20: This example is basically the same as Example 1, except that the amount of acrylate added accounts for 10% of the total mass of the second mixture, and the amount of azobisisobutyronitrile added accounts for 1% of the total mass of the second mixture.

[0045] Example 21: This example is basically the same as Example 1, except that the amount of acrylate added accounts for 15% of the total mass of the second mixture, and the amount of azobisisobutyronitrile added accounts for 2% of the total mass of the second mixture.

[0046] Example 22: This example is basically the same as Example 1, except that the mixture is added to a screw extruder and melt-blended at 175°C.

[0047] Example 23: This example is basically the same as Example 1, except that the mixture is added to a screw extruder and melt-blended at 195°C.

[0048] Comparative Example 1: Referring to Example 1, the acrylate-pyrrole copolymer was replaced with polypyrrole.

[0049] Comparative Example 2: Referring to Example 1, the modified graphene particles were replaced with unmodified graphene particles.

[0050] Comparative Example 3: Referring to Example 1, the reactor was not depressurized during the heating process.

[0051] Comparative Example 4: Referring to Example 1, no inert gas was introduced into the reactor after the copper sulfate aqueous solution was added.

[0052] Experimental Example: To investigate the influence of various preparation parameters on the performance of control cables, the DC resistance of the shielding layer of the cable samples from each embodiment and comparative example was tested. Subsequently, the cable samples from each embodiment and comparative example were subjected to 10,000 mechanical bends with a bending radius of 31 mm, and the DC resistance of the cables from each embodiment and comparative example was tested again. The DC resistance increase rate of each embodiment and comparative example cable was calculated. The specific investigation is as follows: Experiment Example 1: Investigating the Influence of Shielding Layer Material Composition on Cable Performance Using Examples 1, 2, and 3, and Comparative Examples 1 and 2 as experimental comparisons, the cable performance under different shielding layer material compositions is shown in Table 1 below: Table 1 Cable performance under different raw material compositions of shielding layer

[0053] As shown in Table 1, compared with Examples 1, 2, and 3, Example 1 has the lowest DC resistance and DC resistance increase rate of the cable shielding layer, indicating that the shielding performance of the cable in Example 1 is the best. The shielding performance degradation rate after mechanical bending is the lowest. This may be because the shielding layer material composition in Example 1 is the most uniform. Therefore, the shielding layer material composition selected in Example 1 is the best.

[0054] Compared with Comparative Examples 1 and 2, in Example 1, after replacing the acrylate-pyrrole copolymer with polypyrrole or replacing the modified graphene particles with unmodified graphene particles, the DC resistance and DC resistance increase rate of the cable shielding layer both increased. This indicates that the combination of the acrylate-pyrrole copolymer and the modified graphene particles in this application can effectively improve the shielding performance of the cable. Therefore, the raw material composition of the shielding layer in this application is superior.

[0055] Experiment Example 2: Investigating the effect of activator dosage on cable performance. Using Examples 1, 4, and 5 as comparative experiments, the cable performance under different amounts of activator is shown in Table 2 below: Table 2 Cable performance under different activator addition amounts

[0056] As shown in Table 2, compared with Examples 1, 4, and 5, Example 1 has the lowest DC resistance and DC resistance increase rate of the cable shielding layer, indicating that the shielding performance of the cable in Example 1 is the best. This may be because the graphene oxide can be fully activated under the activator addition amount in Example 1. Therefore, the activator addition amount selected in Example 1 is the best.

[0057] Experiment Example 3: Investigating the effects of diethylenetriamine addition pressure and dosage on cable performance. Using Examples 1, 6, 7, 8, and 9 as comparative experiments, the cable performance under different addition pressures and amounts of diethylenetriamine is shown in Table 3 below: Table 3 Cable performance under different addition pressures and dosages of diethylenetriamine

[0058] As shown in Table 3, compared with Examples 1, 6, 7, 8, and 9, Example 1 has the lowest DC resistance and DC resistance increase rate of the cable shielding layer, indicating that the cable of Example 1 has the best shielding performance. This may be because the activated graphene surface can be fully loaded with diethylenetriamine under the addition pressure and amount of diethylenetriamine in Example 1. Therefore, the addition pressure and amount of diethylenetriamine selected in Example 1 are the best.

[0059] Experiment Example 4: Investigating the effect of the reactor heating and depressurization rate on cable performance. Using Examples 1, 10, 11 and Comparative Example 3 as experimental comparisons, the cable performance under different heating and depressurization rates in the reactor is shown in Table 4 below: Table 4. Cable performance under different heating and depressurization rates in the reactor.

[0060] As shown in Table 4, compared with Examples 1, 10, and 11, Example 1 has the lowest DC resistance and DC resistance increase rate of the cable shielding layer, indicating that the shielding performance of the cable in Example 1 is the best. This may be because the loading rate of activated graphene on diethylenetriamine is the highest under the heating and depressurization rate of Example 1. Therefore, the heating and depressurization rate selected in Example 1 is the best.

[0061] Compared with Comparative Example 3, in Example 1, without depressurizing the reactor during heating, both the DC resistance of the cable shield and the rate of increase in DC resistance increased. This may be because the reactivity of diethylenetriamine was affected. Therefore, the reactor pressure and temperature parameters selected in Example 1 were optimal.

[0062] Experiment Example 5: Investigating the effects of copper sulfate aqueous solution addition temperature and dosage on cable performance. Using Examples 1, 12, 13, 14, and 15 as comparative experiments, the cable performance under different addition temperatures and amounts of copper sulfate aqueous solution is shown in Table 5 below: Table 5. Cable performance at different addition temperatures and dosages of copper sulfate aqueous solution.

[0063] As shown in Table 5, compared with Examples 1, 12, 13, 14, and 15, Example 1 has the lowest DC resistance and DC resistance increase rate of the cable shielding layer, indicating that the shielding performance of the cable in Example 1 is the best. This may be because the activated graphene powder can fully chelate copper ions under the addition temperature and amount of copper sulfate aqueous solution in Example 1. Therefore, the addition temperature and amount of copper sulfate aqueous solution selected in Example 1 are the best.

[0064] Experiment Example 6: Investigating the Influence of Thermal Insulation and Pressure Holding Parameters on Cable Performance Using Examples 1, 16, 17 and Comparative Example 4 as experimental comparisons, the cable performance under different thermal insulation and pressure insulation parameters is shown in Table 6 below: Table 6 Cable performance under different thermal insulation and pressure resistance parameters

[0065] As shown in Table 6, compared with Examples 1, 16, and 17, Example 1 has the lowest DC resistance and DC resistance increase rate of the cable shielding layer, indicating that the shielding performance of the cable in Example 1 is the best. This may be because under the heat preservation and pressure preservation parameters of Example 1, diethylenetriamine can be fully grafted onto the graphene powder. Therefore, the heat preservation and pressure preservation parameters selected in Example 1 are the best.

[0066] Compared with Comparative Example 4, in Example 1, without refilling the reactor with inert gas, both the DC resistance and the rate of increase of the DC resistance of the cable shielding layer increased. This may be because copper ions cannot fully chelate with the activated graphene. Therefore, the filling method selected in Example 1 is better.

[0067] Experiment Example 7: Investigating the effect of the second mixture composition on cable performance. Using Examples 1, 18, and 19 as comparative experiments, the cable performance under different compositions of the second mixture is shown in Table 7 below: Table 7 Cable performance under different components of the second mixture.

[0068] As shown in Table 7, compared with Examples 1, 18, and 19, Example 1 has the lowest DC resistance and DC resistance increase rate of the cable shielding layer, indicating that the shielding performance of the cable in Example 1 is the best. This may be because the pyrrole in the second mixture of Example 1 can be fully prepolymerized, so the second mixture of Example 1 is better.

[0069] Experiment Example 8: Investigating the effect of reaction solution composition on cable performance Using Examples 1, 20, and 21 as comparative experiments, the cable performance under different reaction solution compositions is shown in Table 8 below: Table 8 Cable performance under different reaction solution compositions

[0070] As shown in Table 8, compared with Examples 1, 20, and 21, Example 1 has the lowest DC resistance and DC resistance increase rate of the cable shielding layer, indicating that the shielding performance of the cable in Example 1 is the best. This may be because the conversion rate of the acrylate-pyrrole copolymer in the reaction solution of Example 1 is the highest. Therefore, the reaction solution composition selected in Example 1 is the best.

[0071] Experiment Example 9: Investigating the effect of shielding layer extrusion temperature on cable performance Using Examples 1, 22, and 23 as comparative experiments, the cable performance at different extrusion temperatures of the shielding layer is shown in Table 9 below: Table 9 Cable performance at different extrusion temperatures of the shielding layer

[0072] As shown in Table 9, compared with Examples 1, 20, and 21, Example 1 has the lowest DC resistance and DC resistance increase rate of the cable shielding layer, indicating that the shielding performance of the cable in Example 1 is the best. This may be because the shielding layer of Example 1 has the best fluidity at the extrusion temperature. Therefore, the extrusion temperature of the shielding layer selected in Example 1 is the best.

Claims

1. A lightweight aluminum alloy control cable based on a graphene composite shielding layer, characterized in that, It includes a conductor, an insulating layer covering the conductor, a shielding layer covering the insulating layer, and a sheathing layer covering the shielding layer; the shielding layer is made of the following raw materials in parts by weight: 65-75 parts of acrylate-pyrrole copolymer, 10-15 parts of modified graphene particles, 8-12 parts of carbon black, 1-3 parts of silane coupling agent, 2-5 parts of dioctyl phthalate, and 1-2 parts of zinc stearate.

2. The lightweight aluminum alloy control cable based on a graphene composite shielding layer according to claim 1, characterized in that, The silane coupling agent is KH-550 or KH-560.

3. The lightweight aluminum alloy control cable based on a graphene composite shielding layer according to claim 1, characterized in that, The method for preparing the modified graphene particles includes the following steps: 1) Place graphene oxide powder in deionized water and ultrasonically disperse for 15-20 minutes to obtain graphene oxide dispersion; wherein the mass ratio of graphene oxide powder to deionized water is 1:10-12. 2) Add an activator to the graphene oxide dispersion, and then stir at room temperature for 0.5-1 hour under an inert gas atmosphere. After stirring, filter and dry to obtain activated graphene. The amount of activator added is 2-4% of the mass of the graphene oxide dispersion. 3) Add activated graphene powder to an ethanol solution with a mass concentration of 60-80%, and disperse it ultrasonically for 15-20 minutes to obtain an activated graphene dispersion; wherein the mass ratio of activated graphene powder to ethanol solution is 1:6-8. 4) At room temperature, the activated graphene dispersion is added to the reactor, and then inert gas is introduced into the reactor until the pressure inside the reactor reaches 0.25~0.3 MPa. Pressurization is then stopped, and diethylenetriamine is added to the reactor. The reactor is then heated, and pressure is released during the heating process. The heating rate inside the reactor is 4~5℃ / min, and the pressure release rate is 0.01~0.02 MPa / min, until the temperature inside the reactor reaches 60~70℃. Pressure release is then stopped, and the temperature is maintained. An 8~10% (w / w) copper sulfate aqueous solution is then added to the reactor, and inert gas is introduced again during the heat maintenance process until the pressure inside the reactor reaches 0.3~0.4 MPa. The mixture is then maintained at this temperature and pressure for 20~24 h to obtain the first mixture. The amount of diethylenetriamine added is 3~4% of the initial mass of the activated graphene dispersion, and the amount of copper sulfate aqueous solution added is 1~3% of the initial mass of the activated graphene dispersion. 5) Filter the first mixture to obtain solid particles, wash and dry the solid particles to obtain modified graphene particles.

4. The lightweight aluminum alloy control cable based on a graphene composite shielding layer according to claim 3, characterized in that, The activator is hydroxysuccinimide or 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide.

5. The lightweight aluminum alloy control cable based on a graphene composite shielding layer according to claim 1, characterized in that, The preparation method of the acrylate-pyrrole copolymer includes the following steps: 1) Add pyrrole to dimethylformamide and stir until the pyrrole is completely dissolved to obtain a pyrrole solution. Then, add ammonium persulfate aqueous solution dropwise to the pyrrole solution and continue stirring for 15-20 minutes to obtain a second mixture. The mass ratio of pyrrole, ammonium persulfate aqueous solution and dimethylformamide is 1:0.1-0.2:8-10. 2) Add acrylate to the second mixture, stir for 10-15 min, then add azobisisobutyronitrile (AIBN), and continue stirring at 65-70℃ for 45-60 min to obtain the reaction solution; wherein, the amount of acrylate added accounts for 10-15% of the total mass of the second mixture, and the amount of AIBN added accounts for 1-2% of the total mass of the second mixture; 3) Add the reaction solution to 5 to 7 times its mass of anhydrous ethanol, then centrifuge to obtain a precipitate. Wash and dry the precipitate to obtain an acrylate-pyrrole copolymer.

6. The lightweight aluminum alloy control cable based on a graphene composite shielding layer according to claim 5, characterized in that, The mass concentration of the ammonium persulfate aqueous solution is 4-8%.

7. The lightweight aluminum alloy control cable based on a graphene composite shielding layer according to claim 5, characterized in that, The precipitate is dried at a vacuum of 0.08~0.1MPa and a temperature of 45~60℃ for 20~30 minutes.

8. The lightweight aluminum alloy control cable based on a graphene composite shielding layer according to claim 1, characterized in that, The method for preparing the control cable includes the following steps: S1. After drawing the aluminum alloy rod, aluminum alloy monofilaments are obtained. Multiple aluminum alloy monofilaments are twisted together and then annealed to obtain a conductor. S2. The cable insulation material is added into the screw extruder and melted at 160~180℃. It is then extruded onto the conductor through the extruder to form an insulation layer. After cooling, the conductor covered with the insulation layer is obtained. The thickness of the insulation layer is 0.6~1.5mm. S3. According to the stated weight proportions, the shielding layer raw material is added to a mixer and mixed for 30-40 minutes to obtain a mixture. The mixture is then added to a screw extruder and melt-blended at 175-195°C. Subsequently, it is extruded through an extruder onto a conductor with an insulating layer to form a shielding layer. After cooling, a conductor with a shielding layer is obtained. The thickness of the shielding layer is 0.5-1.0 mm. S4. The cable sheath material is added into the screw extruder and melted at 170~180℃. It is then extruded through the extruder onto the conductor covering the shielding layer to form a sheath layer. After cooling, the control cable is obtained. The thickness of the sheath layer is 1.5~2.0mm.

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