A high temperature resistant cable jacket material and method of making the same

Abstract

This invention relates to the field of polymer materials technology, and discloses a high-temperature resistant cable sheath material and its preparation method. The cable sheath material prepared by this invention comprises the following raw materials in parts by weight: 50-70 parts silicone rubber, 12-16 parts EPDM rubber, 3-5 parts ethylene-octene copolymer, 20-30 parts composite flame retardant, 3-5 parts antimony trioxide, 10-15 parts reinforcing agent, 1-3 parts lubricant, 0.8-1.5 parts antioxidant, 2-3 parts vulcanizing agent, 0.5-1 part crosslinking agent, and 2-3 parts silane coupling agent KH570. This cable sheath material not only has excellent mechanical properties and flame retardant properties, but also excellent high-temperature resistance and thermal stability.

Description

Technical Field

[0001] This invention relates to the field of polymer materials technology, specifically to a high-temperature resistant cable sheath material and its preparation method. Background Technology

[0002] High-temperature resistant cable sheathing materials are key components in aerospace, new energy vehicles, rail transportation, and high-temperature industrial sensors, and their performance directly determines the reliability and lifespan of signal transmission in extreme thermal environments. Silicone rubber, due to its unique silicon-oxygen backbone structure, possesses excellent electrical insulation, physiological inertness, and wide-temperature-range flexibility, making it a preferred matrix material for manufacturing high-temperature resistant cable sheaths. However, when traditional silicone rubber sheaths are exposed to temperatures above 250°C for extended periods or subjected to periodic thermal shock, the methyl groups in their side chains are prone to thermal oxidative decomposition, generating silanol groups and further inducing backbone degradation, leading to increased material hardness, loss of elasticity, surface cracking, and even pulverization. Furthermore, the low intrinsic thermal conductivity of silicone rubber means that localized overheating can accelerate these aging processes, making it difficult to meet the urgent requirements of modern high-power-density equipment for sheathing materials that can withstand long-term temperatures of 250°C or even 300°C. Summary of the Invention

[0003] To address the aforementioned technical problems, this invention provides a high-temperature resistant cable sheath material and its preparation method.

[0004] The objective of this invention can be achieved through the following technical solutions:

[0005] A high-temperature resistant cable sheath material comprises the following raw materials in parts by weight: 50-70 parts silicone rubber, 12-16 parts EPDM rubber, 3-5 parts ethylene-octene copolymer, 20-30 parts composite flame retardant, 3-5 parts antimony trioxide, 10-15 parts reinforcing agent, 1-3 parts lubricant, 0.8-1.5 parts antioxidant, 2-3 parts vulcanizing agent, 0.5-1 part crosslinking agent, and 2-3 parts silane coupling agent KH570;

[0006] Furthermore, the composite flame retardant is a mixture of magnesium hydroxide and ammonium polyphosphate, and the mass ratio of magnesium hydroxide to ammonium polyphosphate is 1:2;

[0007] Furthermore, the lubricant is either polyethylene wax or silicone powder;

[0008] Furthermore, the antioxidant is antioxidant 1010;

[0009] Furthermore, the vulcanizing agent is a peroxide vulcanizing agent;

[0010] Furthermore, the crosslinking agent is TAIC;

[0011] The reinforcing agent is prepared by the following steps:

[0012] Step A1: Mix 3 mol / L nitric acid solution and 10 mol / L sulfuric acid solution in a 1:3 ratio to prepare a mixed acid, then add carbon nanotubes and stir at room temperature for 12-20 h, filter, wash and dry to obtain carboxylated carbon nanotubes.

[0013] Furthermore, in step A1, the ratio of the mixed acid to carbon nanotubes is 100 mL: 0.5 g;

[0014] Step A2: Terephthalic acid and 2-aminoterephthalic acid were ultrasonically dispersed in N,N-dimethylformamide for 20 min to prepare an organic ligand solution; cerium(IV) ammonium nitrate and carboxylated carbon nanotubes were ultrasonically dispersed in 15 mL of N,N-dimethylformamide for 10 min, then stirred for 30 min, followed by the addition of formic acid and the organic ligand solution, and the mixture was transferred to a 100℃ water bath for 12 h. After centrifugation, washing, and drying, carbon nanotubes@Ce-MOF were obtained.

[0015] Furthermore, in step A2, the ratio of terephthalic acid, 2-aminoterephthalic acid, and N,N-dimethylformamide in the organic solution is 0.85-1.05 g: 0.22-0.37 g: 40 mL.

[0016] Furthermore, in step A2, the ratio of cerium(IV) ammonium nitrate, carboxylated carbon nanotubes, formic acid, and organic ligand solution is 3-3.5 g: 0.1-0.2 g: 1.2-2.4 mL: 40 mL;

[0017] Step A3: Under nitrogen conditions, carbon nanotubes @Ce-MOF are ultrasonically dispersed in anhydrous toluene for 30 min, then polysiloxane modifier is added, and the mixture is heated to 70-80℃ and refluxed for 12-24 h. After cooling to room temperature, the mixture is washed with anhydrous ethanol and vacuum dried to obtain the reinforcing agent.

[0018] Furthermore, in step A3, the molar ratio of amino groups in the carbon nanotubes@Ce-MOF and epoxy groups in the polysiloxane modifier is 1:1.5-2;

[0019] Furthermore, the polysiloxane modifier mentioned in step A3 is specifically prepared by the following steps:

[0020] Step B1: Under nitrogen atmosphere, maleic anhydride is dissolved in anhydrous acetone, and 3-aminopropyltriethoxysilane is slowly added dropwise over 30 min. The mixture is reacted at room temperature for 4 h, then triethylamine and hydroquinone are added and stirred for 15 min. Acetic anhydride is then added, and the temperature is raised to 70-80 °C and reacted for 4-6 h. After cooling, the mixture is allowed to stand overnight, washed with anhydrous ethanol, and dried under vacuum to obtain the functional silane.

[0021] Further, in step B1, the ratio of maleic anhydride, anhydrous acetone, 3-aminopropyltriethoxysilane, triethylamine, hydroquinone, and acetic anhydride is 0.05 mol: 60 mL: 0.05 mol: 0.5-1 mL: 0.05-0.1 g: 5-6 mL;

[0022] Step B2: Add functional silane and KH560 to ethanol and water and stir at room temperature for 30 min to prepare a pre-hydrolyzed solution; add trimethylmethoxysilane, polyvinylpyrrolidone, sodium dodecyl sulfonate and deionized water to a flask and stir for 40 min, add the pre-hydrolyzed solution and stir for 15 min, then add triethylamine and continue stirring for 3-4 h, then add KH560 and stir for 2-3 h, filter and wash to obtain polysiloxane modifier;

[0023] Further, in step B2, the ratio of trimethylmethoxysilane, polyvinylpyrrolidone, sodium dodecyl sulfonate, deionized water, pre-hydrolyzed solution, triethylamine, and KH560 is 10-15g:0.15-0.2g:0.3-0.5g:25mL:6.5mL:7.5-8.5mL:0.5-1mL;

[0024] Furthermore, in step B2, the ratio of functional silane, KH560, ethanol, and water in the pre-hydrolyzed solution is 1.5-2.5g:0.5mL:5mL:1mL.

[0025] A method for preparing a high-temperature resistant cable sheath material includes the following steps:

[0026] Weigh the raw materials according to the weight proportions. Add the silane coupling agent KH570, composite flame retardant, antimony trioxide and reinforcing agent to the internal mixer and mix for 1-2 minutes. Then add silicone rubber, EPDM rubber and ethylene-octene copolymer and mix under nitrogen and 70-90℃ for 15-25 minutes. Then add lubricant and antioxidant and mix for 5-8 minutes. Then transfer to an open mill, add vulcanizing agent and crosslinking agent, and mix at 40-50℃ for 8-10 minutes. Pass through a thin mill 3-5 times, extrude the sheet, let it stand for 12 hours, and then extrude and vulcanize to obtain the high temperature resistant cable sheath material.

[0027] The beneficial effects of this invention are:

[0028] The cable sheath material prepared by this invention is made of silicone rubber and EPDM rubber as the main base materials, with the addition of functional additives such as ethylene-octene copolymer, silane coupling agent KH570, composite flame retardant, antimony trioxide, reinforcing agent and vulcanizing agent. This cable sheath material not only has excellent mechanical properties and flame retardant properties, but also excellent high temperature resistance and thermal stability.

[0029] The cable sheath material prepared in this invention incorporates a reinforcing agent, improving its high-temperature resistance and thermal stability. Specifically, carbon nanotubes, serving as the core framework of the reinforcing agent, construct a three-dimensional thermally conductive network within the composite material. When the sheath experiences localized overheating, heat is rapidly dissipated through the carbon nanotube channels, preventing localized ablation or accelerated aging caused by concentrated hotspots. Silicone rubber, as the main substrate, undergoes aging primarily through a free radical chain reaction at high temperatures. The MOF in the reinforcing agent utilizes its porous structure to capture the reactive peroxide radicals (ROO·) generated by the cracking of silicone rubber, and utilizes the transition metal ions (Ce·) within the MOF nodes... 3+ / Ce 4+ The unique variable valence state of the polysiloxane allows it to catalyze the electron transfer of free radicals like an enzyme, converting them into stable molecules, thereby breaking the degradation chain and significantly improving thermal oxidation stability. The outermost polysiloxane layer itself is a "silicone rubber analogue," perfectly integrating into the silicone rubber matrix, ensuring good compatibility of the reinforcing agent within the matrix. Simultaneously, the imide rings in the functional silanes introduced by the polysiloxane enhance high-temperature resistance. This is because polysiloxanes containing imide rings have an increased glass transition temperature, meaning that at high temperatures, the microspheres remain rigid glassy spheres, preventing softening and collapse, thus continuously providing support and reinforcement, ensuring the long-term reliability of the sheath material under extreme high temperatures. Detailed Implementation

[0030] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] Example 1: The reinforcing agent was prepared by the following steps:

[0032] Step A1: Mix 3 mol / L nitric acid solution and 10 mol / L sulfuric acid solution in a ratio of 1:3 to prepare 100 mL of mixed acid, then add 0.5 g of carbon nanotubes and stir at room temperature for 12 h. Filter, wash and dry to obtain carboxylated carbon nanotubes.

[0033] Step A2: 1.05 g of terephthalic acid and 0.22 g of 2-aminoterephthalic acid were ultrasonically dispersed in 40 mL of N,N-dimethylformamide for 20 min to prepare an organic ligand solution; 3 g of cerium(IV) ammonium nitrate and 0.1 g of carboxylated carbon nanotubes were ultrasonically dispersed in 15 mL of N,N-dimethylformamide for 10 min, and then stirred for 30 min. Subsequently, 1.2 mL of formic acid and 40 mL of organic ligand solution were added, and the mixture was transferred to a 100 °C water bath and reacted for 12 h. After centrifugation, washing, and drying, carbon nanotubes@Ce-MOF were obtained.

[0034] Step A3: Under nitrogen atmosphere, carbon nanotubes @Ce-MOF are ultrasonically dispersed in anhydrous toluene for 30 min, then polysiloxane modifier is added, and the mixture is heated to 70℃ and refluxed for 12 h. After cooling to room temperature, the mixture is washed with anhydrous ethanol and vacuum dried to obtain the reinforcing agent. The molar ratio of amino groups in carbon nanotubes @Ce-MOF to epoxy groups in polysiloxane modifier is 1:1.5.

[0035] Preferably, the polysiloxane modifier in step A3 is prepared by the following steps:

[0036] Step B1: Under nitrogen atmosphere, dissolve 0.05 mol maleic anhydride in 60 mL anhydrous acetone, slowly add 0.05 mol 3-aminopropyltriethoxysilane dropwise over 30 min, and react at room temperature for 4 h. Then add 0.5 mL triethylamine and 0.05 g hydroquinone and stir for 15 min. Then add 5 mL acetic anhydride and heat to 70 °C and react for 4 h. After cooling, let stand overnight, wash with anhydrous ethanol, and vacuum dry to obtain the functional silane.

[0037] Step B2: Add 1.5g of functional silane and 0.5mL of KH560 to 5mL of ethanol and 1mL of water and stir at room temperature for 30min to obtain a pre-hydrolyzed solution; add 10g of trimethylmethoxysilane, 0.15g of polyvinylpyrrolidone, 0.3g of sodium dodecyl sulfonate and 25mL of deionized water to a flask and stir for 40min, add 6.5mL of the pre-hydrolyzed solution and stir for 15min, then add 7.5mL of triethylamine and continue stirring for 3h, then add 0.5mL of KH560 and stir for 2h, filter and wash to obtain the polysiloxane modifier.

[0038] Example 2: The reinforcing agent was prepared by the following steps:

[0039] Step A1: Mix 3 mol / L nitric acid solution and 10 mol / L sulfuric acid solution in a ratio of 1:3 to prepare 100 mL of mixed acid, then add 0.5 g of carbon nanotubes and stir at room temperature for 16 h. Filter, wash and dry to obtain carboxylated carbon nanotubes.

[0040] Step A2: Disperse 0.95g of terephthalic acid and 0.3g of 2-aminoterephthalic acid in 40mL of N,N-dimethylformamide by ultrasonication for 20min to obtain an organic ligand solution; disperse 3.2g of cerium(IV) ammonium nitrate and 0.15g of carboxylated carbon nanotubes in 15mL of N,N-dimethylformamide by ultrasonication for 10min, then stir for 30min, then add 1.8mL of formic acid and 40mL of organic ligand solution, and transfer to a 100℃ water bath for reaction for 12h. Centrifuge, wash and dry to obtain carbon nanotubes@Ce-MOF;

[0041] Step A3: Under nitrogen atmosphere, carbon nanotubes @Ce-MOF are ultrasonically dispersed in anhydrous toluene for 30 min, then polysiloxane modifier is added, and the mixture is heated to 75℃ and refluxed for 18 h. After cooling to room temperature, the mixture is washed with anhydrous ethanol and vacuum dried to obtain the reinforcing agent. The molar ratio of amino groups in carbon nanotubes @Ce-MOF to epoxy groups in polysiloxane modifier is 1:1.8.

[0042] Preferably, the polysiloxane modifier in step A3 is prepared by the following steps:

[0043] Step B1: Under nitrogen atmosphere, dissolve 0.05 mol maleic anhydride in 60 mL anhydrous acetone, slowly add 0.05 mol 3-aminopropyltriethoxysilane dropwise over 30 min, and react at room temperature for 4 h. Then add 0.75 mL triethylamine and 0.075 g hydroquinone and stir for 15 min. Then add 5.5 mL acetic anhydride and heat to 75 °C for 5 h. After cooling, let stand overnight, wash with anhydrous ethanol, and vacuum dry to obtain the functional silane.

[0044] Step B2: Add 2g of functional silane and 0.5mL of KH560 to 5mL of ethanol and 1mL of water and stir at room temperature for 30min to obtain a pre-hydrolyzed solution; add 12g of trimethylmethoxysilane, 0.18g of polyvinylpyrrolidone, 0.4g of sodium dodecyl sulfonate and 25mL of deionized water to a flask and stir for 40min, add 6.5mL of the pre-hydrolyzed solution and stir for 15min, then add 8mL of triethylamine and continue stirring for 3.5h, then add 0.8mL of KH560 and stir for 2.5h, filter and wash to obtain the polysiloxane modifier.

[0045] Example 3: The reinforcing agent was prepared by the following steps:

[0046] Step A1: Mix 3 mol / L nitric acid solution and 10 mol / L sulfuric acid solution in a ratio of 1:3 to prepare 100 mL of mixed acid, then add 0.5 g of carbon nanotubes and stir at room temperature for 20 h. Filter, wash and dry to obtain carboxylated carbon nanotubes.

[0047] Step A2: Disperse 0.85g of terephthalic acid and 0.37g of 2-aminoterephthalic acid in 40mL of N,N-dimethylformamide by ultrasonication for 20min to obtain an organic ligand solution; disperse 3.5g of cerium(IV) ammonium nitrate and 0.2g of carboxylated carbon nanotubes in 15mL of N,N-dimethylformamide by ultrasonication for 10min, then stir for 30min, then add 2.4mL of formic acid and 40mL of organic ligand solution, and transfer to a 100℃ water bath for reaction for 12h. Centrifuge, wash and dry to obtain carbon nanotubes@Ce-MOF;

[0048] Step A3: Under nitrogen atmosphere, carbon nanotubes @Ce-MOF are ultrasonically dispersed in anhydrous toluene for 30 min, then polysiloxane modifier is added, and the mixture is heated to 80℃ and refluxed for 24 h. After cooling to room temperature, the mixture is washed with anhydrous ethanol and vacuum dried to obtain the reinforcing agent. The molar ratio of amino groups in carbon nanotubes @Ce-MOF to epoxy groups in polysiloxane modifier is 1:2.

[0049] Preferably, the polysiloxane modifier in step A3 is prepared by the following steps:

[0050] Step B1: Under nitrogen atmosphere, dissolve 0.05 mol maleic anhydride in 60 mL anhydrous acetone, slowly add 0.05 mol 3-aminopropyltriethoxysilane dropwise over 30 min, and react at room temperature for 4 h. Then add 1 mL triethylamine and 0.1 g hydroquinone and stir for 15 min. Then add 6 mL acetic anhydride and heat to 80 °C for 6 h. After cooling, let stand overnight, wash with anhydrous ethanol, and vacuum dry to obtain the functional silane.

[0051] Step B2: Add 2.5g of functional silane and 0.5mL of KH560 to 5mL of ethanol and 1mL of water and stir at room temperature for 30min to obtain a pre-hydrolyzed solution; add 15g of trimethylmethoxysilane, 0.2g of polyvinylpyrrolidone, 0.5g of sodium dodecyl sulfonate and 25mL of deionized water to a flask and stir for 40min, add 6.5mL of the pre-hydrolyzed solution and stir for 15min, then add 8.5mL of triethylamine and continue stirring for 4h, then add 1mL of KH560 and stir for 3h, filter and wash to obtain the polysiloxane modifier.

[0052] Example 4: A method for preparing a high-temperature resistant cable sheath material includes the following steps:

[0053] 50 parts silicone rubber, 12 parts EPDM rubber, 3 parts ethylene-octene copolymer, 20 parts composite flame retardant, 3 parts antimony trioxide, 10 parts reinforcing agent prepared in Example 1, 1 part lubricant, 0.8 parts antioxidant, 2 parts vulcanizing agent, 0.5 parts crosslinking agent, and 2 parts silane coupling agent KH570.

[0054] Preferably, the composite flame retardant is a mixture of magnesium hydroxide and ammonium polyphosphate, and the mass ratio of magnesium hydroxide to ammonium polyphosphate is 1:2;

[0055] Preferably, the lubricant is polyethylene wax;

[0056] Preferably, the antioxidant is antioxidant 1010;

[0057] Preferably, the vulcanizing agent is dicumyl peroxide;

[0058] Preferably, the crosslinking agent is TAIC;

[0059] Weigh the raw materials according to the weight parts, add silane coupling agent KH570, composite flame retardant, antimony trioxide and the reinforcing agent prepared in Example 1 to the internal mixer and mix for 1 min, then add silicone rubber, EPDM rubber and ethylene-octene copolymer, mix under nitrogen and 70°C for 15 min, then add lubricant and antioxidant and mix for 5 min, then transfer to open mill, add vulcanizing agent and crosslinking agent, mix at 40°C for 8 min, pass through thin mill 3 times, sheet out, let stand for 12 h, then extrude and vulcanize to obtain high temperature resistant cable sheath material.

[0060] Example 5: A method for preparing a high-temperature resistant cable sheath material includes the following steps:

[0061] 60 parts silicone rubber, 14 parts EPDM rubber, 4 parts ethylene-octene copolymer, 25 parts composite flame retardant, 4 parts antimony trioxide, 12 parts reinforcing agent prepared in Example 2, 2 parts lubricant, 1.2 parts antioxidant, 2.5 parts vulcanizing agent, 0.8 parts co-crosslinking agent, and 2.5 parts silane coupling agent KH570.

[0062] Preferably, the composite flame retardant is a mixture of magnesium hydroxide and ammonium polyphosphate, and the mass ratio of magnesium hydroxide to ammonium polyphosphate is 1:2;

[0063] Preferably, the lubricant is silicone powder;

[0064] Preferably, the antioxidant is antioxidant 1010;

[0065] Preferably, the vulcanizing agent is dicumyl peroxide;

[0066] Preferably, the crosslinking agent is TAIC;

[0067] Weigh the raw materials according to the weight parts, add the silane coupling agent KH570, composite flame retardant, antimony trioxide and the reinforcing agent prepared in Example 2 to the internal mixer and mix for 1.5 min, then add silicone rubber, EPDM rubber and ethylene-octene copolymer, and mix under nitrogen and 80°C for 20 min, then add lubricant and antioxidant and mix for 6.5 min, then transfer to open mill, add vulcanizing agent and crosslinking agent, and mix at 45°C for 9 min, pass through thin mill 4 times, sheet out, let stand for 12 h, and then extrude and vulcanize to obtain high temperature resistant cable sheath material.

[0068] Example 6: A method for preparing a high-temperature resistant cable sheath material includes the following steps:

[0069] 70 parts silicone rubber, 16 parts EPDM rubber, 5 parts ethylene-octene copolymer, 30 parts composite flame retardant, 5 parts antimony trioxide, 15 parts reinforcing agent prepared in Example 3, 3 parts lubricant, 1.5 parts antioxidant, 3 parts vulcanizing agent, 1 part crosslinking agent, and 3 parts silane coupling agent KH570.

[0070] Preferably, the composite flame retardant is a mixture of magnesium hydroxide and ammonium polyphosphate, and the mass ratio of magnesium hydroxide to ammonium polyphosphate is 1:2;

[0071] Preferably, the lubricant is polyethylene wax;

[0072] Preferably, the antioxidant is antioxidant 1010;

[0073] Preferably, the vulcanizing agent is dicumyl peroxide;

[0074] Preferably, the crosslinking agent is TAIC;

[0075] Weigh the raw materials according to the weight parts, add silane coupling agent KH570, composite flame retardant, antimony trioxide and the reinforcing agent prepared in Example 3 to the internal mixer and mix for 2 minutes, then add silicone rubber, EPDM rubber and ethylene-octene copolymer, and mix under nitrogen and 90°C for 25 minutes, then add lubricant and antioxidant and mix for 8 minutes, then transfer to open mill, add vulcanizing agent and crosslinking agent, and mix at 50°C for 10 minutes, pass through thin mill 5 times, sheet out, let stand for 12 hours, and then extrude and vulcanize to obtain high temperature resistant cable sheath material.

[0076] Comparative Example 1: This comparative example is a cable sheath material. The difference between this example and Example 6 is that silica is used instead of the reinforcing agent prepared in Example 3. All other aspects are the same.

[0077] Comparative Example 2: This comparative example is a cable sheath material. The difference between this example and Example 6 is that the carbon nanotubes@Ce-MOF prepared in Example 3 are used instead of the reinforcing agent prepared in Example 3. All other aspects are the same.

[0078] Comparative Example 3: This comparative example is a cable sheath material. The difference from Example 6 is that the polysiloxane modifier prepared in Example 3 is used instead of the reinforcing agent prepared in Example 3.

[0079] The cable sheath materials prepared in Examples 4-6 and Comparative Examples 1-3 were subjected to performance tests:

[0080] Mechanical property testing: Tensile strength and elongation at break were tested in accordance with GB / T 528-2009 "Determination of tensile stress-strain properties of vulcanized rubber or thermoplastic rubber".

[0081] Heat aging resistance test: The retention rate of tensile strength and elongation at break after heat aging was tested according to GB / T 3512-2014 "Accelerated aging and heat resistance test of vulcanized rubber or thermoplastic rubber in hot air". The retention rate = performance after aging / performance before aging × 100%.

[0082] Flame retardant performance test: The limiting oxygen index was tested in accordance with GB / T 10707-2008 "Determination of the flammability of rubber" standard;

[0083] The test results are shown in Table 1:

[0084] Table 1: Performance Test Results

[0085]

[0086] As can be seen from Table 1, the cable sheath material prepared by this invention not only has excellent tensile strength and elongation at break, but also excellent high temperature resistance and flame retardant properties.

[0087] The above content is merely an example and illustration of the concept of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described or use similar methods to replace them, as long as they do not deviate from the scope defined by the inventive concept, they should all fall within the protection scope of the present invention.

Claims

1. A high temperature resistant cable jacket material characterized in that, The raw materials include the following parts by weight: 50-70 parts silicone rubber, 12-16 parts EPDM rubber, 3-5 parts ethylene-octene copolymer, 20-30 parts composite flame retardant, 3-5 parts antimony trioxide, 10-15 parts reinforcing agent, 1-3 parts lubricant, 0.8-1.5 parts antioxidant, 2-3 parts vulcanizing agent, 0.5-1 part co-crosslinking agent, and 2-3 parts silane coupling agent KH570; The composite flame retardant is a mixture of magnesium hydroxide and ammonium polyphosphate, and the mass ratio of magnesium hydroxide to ammonium polyphosphate is 1:

2. The reinforcing agent is prepared by coating Ce-MOF onto the surface of carbon nanotubes, and then reacting the amino groups on the surface of Ce-MOF with the epoxy groups on the surface of the polysiloxane modifier. The polysiloxane modifier is prepared by condensation reaction of trimethylmethoxysilane, functional silane and KH560 as the main raw materials. The functional silane is prepared by reacting maleic anhydride and 3-aminopropyltriethoxysilane.

2. A high temperature resistant cable jacket material according to claim 1, wherein, The reinforcing agent is prepared by the following steps: Step A1: Mix 3 mol / L nitric acid solution and 10 mol / L sulfuric acid solution in a 1:3 ratio to prepare a mixed acid, then add carbon nanotubes and stir at room temperature for 12-20 h, filter, wash and dry to obtain carboxylated carbon nanotubes. Step A2: Terephthalic acid and 2-aminoterephthalic acid are ultrasonically dispersed in N,N-dimethylformamide for 20 min to prepare an organic ligand solution; cerium(IV) ammonium nitrate and carboxylated carbon nanotubes are ultrasonically dispersed in 15 mL of N,N-dimethylformamide for 10 min, then stirred for 30 min, followed by the addition of formic acid and the organic ligand solution, and then transferred to a 100℃ water bath for 12 h. After centrifugation, washing, and drying, carbon nanotubes@Ce-MOF are obtained. Step A3: Under nitrogen atmosphere, carbon nanotubes @Ce-MOF are ultrasonically dispersed in anhydrous toluene for 30 min, then polysiloxane modifier is added, and the mixture is heated to 70-80℃ and refluxed for 12-24 h. After cooling to room temperature, the mixture is washed with anhydrous ethanol and vacuum dried to obtain the reinforcing agent.

3. A high temperature resistant cable jacket material according to claim 2, wherein, In step A1, the ratio of mixed acid to carbon nanotubes is 100 mL: 0.5 g.

4. A high temperature resistant cable jacket material according to claim 2, wherein, In step A2, the ratio of terephthalic acid, 2-aminoterephthalic acid, and N,N-dimethylformamide in the organic solution is 0.85-1.05 g: 0.22-0.37 g: 40 mL.

5. The high-temperature resistant cable sheath material according to claim 2, characterized in that, In step A2, the ratio of cerium ammonium nitrate, carboxylated carbon nanotubes, formic acid, and organic ligand solution is 3-3.5g:0.1-0.2g:1.2-2.4mL:40mL.

6. The high-temperature resistant cable sheath material according to claim 2, characterized in that, In step A3, the molar ratio of amino groups in the carbon nanotubes @Ce-MOF and epoxy groups in the polysiloxane modifier is 1:1.5-2.

7. The high-temperature resistant cable sheath material according to claim 2, characterized in that, The polysiloxane modifier mentioned in step A3 is prepared by the following steps: Step B1: Under nitrogen atmosphere, maleic anhydride is dissolved in anhydrous acetone, and 3-aminopropyltriethoxysilane is slowly added dropwise over 30 min. The mixture is reacted at room temperature for 4 h, then triethylamine and hydroquinone are added and stirred for 15 min. Acetic anhydride is then added, and the temperature is raised to 70-80 °C and reacted for 4-6 h. After cooling, the mixture is allowed to stand overnight, washed with anhydrous ethanol, and dried under vacuum to obtain the functional silane. Step B2: Add functional silane and KH560 to ethanol and water and stir at room temperature for 30 min to prepare a pre-hydrolyzed solution; add trimethylmethoxysilane, polyvinylpyrrolidone, sodium dodecyl sulfonate and deionized water to a flask and stir for 40 min, add the pre-hydrolyzed solution and stir for 15 min, then add triethylamine and continue stirring for 3-4 h, then add KH560 and stir for 2-3 h, filter and wash to obtain the polysiloxane modifier.

8. The high-temperature resistant cable sheath material according to claim 7, characterized in that, In step B1, the ratio of maleic anhydride, anhydrous acetone, 3-aminopropyltriethoxysilane, triethylamine, hydroquinone, and acetic anhydride is 0.05 mol: 60 mL: 0.05 mol: 0.5-1 mL: 0.05-0.1 g: 5-6 mL.

9. The high-temperature resistant cable sheath material according to claim 7, characterized in that, In step B2, the ratio of trimethylmethoxysilane, polyvinylpyrrolidone, sodium dodecyl sulfonate, deionized water, pre-hydrolyzed solution, triethylamine, and KH560 is 10-15g:0.15-0.2g:0.3-0.5g:25mL:6.5mL:7.5-8.5mL:0.5-1mL. In the pre-hydrolyzed solution, the ratio of functional silane, KH560, ethanol, and water is 1.5-2.5g:0.5mL:5mL:1mL.

10. A method for preparing the high-temperature resistant cable sheath material according to any one of claims 1-9, characterized in that, Includes the following steps: Weigh the raw materials according to the weight proportions. Add the silane coupling agent KH570, composite flame retardant, antimony trioxide and reinforcing agent to the internal mixer and mix for 1-2 minutes. Then add silicone rubber, EPDM rubber and ethylene-octene copolymer and mix under nitrogen and 70-90℃ for 15-25 minutes. Then add lubricant and antioxidant and mix for 5-8 minutes. Then transfer to an open mill, add vulcanizing agent and crosslinking agent, and mix at 40-50℃ for 8-10 minutes. Pass through a thin mill 3-5 times, extrude the sheet, let it stand for 12 hours, and then extrude and vulcanize to obtain the high temperature resistant cable sheath material.

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