High-strength cable sheath material as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of cable sheath materials, and particularly relates to a high-strength cable sheath material and a preparation method and application thereof. The high-strength cable sheath material comprises the following raw materials in parts by weight: 50-80 parts of polyurethane, 1-3 parts of a dispersing agent, 1-3 parts of an antioxidant, 10-15 parts of a flame retardant and 1-5 parts of modified silicon carbide. The flame retardant, the modified silicon carbide, the dispersing agent, the antioxidant and other components are added into polyurethane to obtain the high-strength cable sheath material, and the cable sheath material has excellent mechanical properties, wear resistance, flame retardance and antistatic capacity.

Description

Technical Field

[0001] The present invention belongs to the technical field of cable sheath materials, and in particular relates to a high-strength cable sheath material and a preparation method and application thereof. Background Art

[0002] Thermoplastic polyurethane (TPU) elastomer is a (AB) n Block linear polymers, composed of flexible soft segments and rigid hard segments, have been widely used in the field of cable sheath materials due to their excellent oil resistance, low temperature resistance and high elasticity.

[0003] However, with the widespread application of power cables in high-voltage and high-current scenarios such as new energy and rail transit, TPU as a cable sheathing material faces severe performance challenges. Traditional TPU cable sheathing materials present numerous problems in practical applications: on the one hand, the flexible nature of the TPU molecular chain makes it difficult for its tensile strength and abrasion resistance to meet the mechanical protection requirements of high-voltage cables; on the other hand, TPU's limiting oxygen index is far below the cable flame retardant standard, and it produces molten droplets during combustion, posing a significant threat to life, property, and the environment. Furthermore, existing technologies typically employ solutions such as the addition of inorganic flame retardants (such as aluminum hydroxide) or physical blending of flame-retardant plastics, but these methods result in a decrease in the material's elongation at break and introduce interfacial compatibility issues. Therefore, it is necessary to improve thermoplastic polyurethane-based cable sheathing materials to address these issues. Summary of the Invention

[0004] In order to overcome the deficiencies of the prior art, the primary purpose of the present invention is to provide a high-strength cable sheath material, which has flame retardant properties, wear resistance, mechanical properties and antistatic capabilities.

[0005] Another object of the present invention is to provide a method for preparing the above-mentioned high-strength cable sheath material.

[0006] The third object of the present invention is to provide an application of the above-mentioned high-strength cable sheath material in the preparation of cable sheaths.

[0007] The purpose of the present invention is achieved through the following technical solutions: A high-strength cable sheath material, comprising the following raw materials in parts by weight: 50-80 parts of polyurethane, 1-3 parts of dispersant, 1-3 parts of antioxidant, 10-15 parts of flame retardant, and 1-5 parts of modified silicon carbide; The modified silicon carbide is prepared by the following preparation process: (1) dispersing silicon carbide powder into hydrogen peroxide solution, reacting under heating conditions, centrifuging after the reaction, washing and drying the collected product to obtain pretreated silicon carbide powder; (2) Chitosan, a surfactant, and acetic acid are added to water and stirred, and sodium molybdate and thiourea are added and stirred continuously to obtain a precursor solution; the pretreated silicon carbide powder obtained in step (1) is added to the precursor solution to carry out a hydrothermal reaction, filtered, and the collected product is washed, dried, and carbonized to obtain the modified silicon carbide.

[0008] Furthermore, in step (1), the amount ratio of the silicon carbide powder to the hydrogen peroxide solution is (0.8-1) g:100 mL; the heating temperature is 75-85° C., and the reaction time is 5-8 h.

[0009] Furthermore, in step (2), the mass ratio of chitosan, surfactant, acetic acid, sodium molybdate, thiourea and pretreated silicon carbide powder is (3-6): (4-4.5): (9-10): (1-1.5): (3-3.5): 10; the surfactant is a polyethylene ether-polypropylene ether-polyethylene ether triblock copolymer; the stirring time is 1-2 h; and the continued stirring time is 1-2 h.

[0010] Furthermore, the temperature of the hydrothermal reaction in step (2) is 210-230°C, and the time is 22-30 h; the temperature of the carbonization is 650-700°C, and the time is 1-1.5 h.

[0011] Furthermore, the preparation process of the flame retardant is as follows: (a) adding an ethanol solution of 5-hydroxy-1-naphthaldehyde to an ethanol solution of 1,10-phenanthroline-3,8-diamine, and reacting under an inert gas atmosphere and heating; after the reaction, cooling the reaction solution to room temperature, filtering, and washing and drying the collected solid to obtain intermediate 1; (b) adding the intermediate 1 and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide to ethanol and subjecting them to reflux reaction under an inert gas atmosphere; after the reaction is completed, the flame retardant is obtained by purification.

[0012] This flame retardant is prepared by modifying 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) using 5-hydroxy-1-naphthaldehyde and 1,10-phenanthroline-3,8-diamine. The flame retardant's flame retardancy mechanism includes three aspects: 1. Gas-phase flame retardancy: The phosphaphenanthrene structure in the flame retardant decomposes at high temperatures to produce PO· free radicals, which in turn capture H· and OH· active free radicals in the combustion chain reaction. The phenanthroline-naphthaldehyde skeleton promotes carbonization, forming a dense carbon layer that isolates oxygen and heat. 2. Condensed-phase flame retardancy: The phosphorus in the flame retardant promotes dehydration and carbonization of the polymer matrix, forming an expanded carbon layer. The large number of aromatic rings provides high thermal stability, and the hydroxyl and nitrogen atoms synergistically promote cross-linking carbonization. 3. Physical barrier effect: The large conjugated planar structure in the flame retardant forms a physical barrier layer in the material, and upon decomposition, it produces inert gases (CO2, N2) that dilute the combustible gas.

[0013] Furthermore, in step (a), the molar ratio of 5-hydroxy-1-naphthaldehyde to 1,10-phenanthroline-3,8-diamine is (2-2.5):1; the concentration of the ethanol solution of 5-hydroxy-1-naphthaldehyde is 0.2-0.4 mol / L; the concentration of the ethanol solution of 1,10-phenanthroline-3,8-diamine is 0.2-0.3 mol / L; the heating temperature is 60-75°C, and the reaction time is 4-6 h.

[0014] Furthermore, in step (b), the molar ratio of the intermediate 1 to 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide is 1:(2-2.5); and the reflux reaction time is 2-3 days.

[0015] Furthermore, the polyurethane is a polyether thermoplastic polyurethane with a hardness of 75-85A; the dispersant is RL16; and the antioxidant is at least one of antioxidant 1010, antioxidant 1024, and antioxidant 168.

[0016] The method for preparing the above-mentioned high-strength cable sheath material comprises the following steps: The polyurethane, dispersant, antioxidant, flame retardant and modified silicon carbide are uniformly mixed according to the weight proportions, and then melt-extruded and granulated to obtain a waterproof and corrosion-resistant cable sheath material.

[0017] Application of the above-mentioned high-strength cable sheath material in the preparation of cable sheaths.

[0018] The present invention has the following effects compared to the prior art: 1. The present invention obtains a high-strength cable sheath material by adding flame retardants, modified silicon carbide, dispersants, and antioxidants to polyurethane. The cable sheath material has excellent mechanical properties, wear resistance, flame retardancy, and antistatic capabilities.

[0019] 2. The flame retardant of the present invention can not only significantly improve the flame retardant properties of cable sheath materials, but the hydroxyl groups in the flame retardant molecules can also form a strong hydrogen bond network with the -NH-CO-O- in polyurethane, or form covalent bonds with the isocyanate groups in polyurethane to improve its compatibility and dispersibility, and enhance the interfacial bonding strength.

[0020] 3. The present invention significantly improves the mechanical properties of the cable sheath material by adding modified silicon carbide as a reinforcing agent, while also improving its wear resistance and antistatic ability. Silicon carbide is pretreated to obtain hydroxylated silicon carbide, which is then treated with chitosan-assisted hydrothermal method and carbonization to form modified silicon carbide with a surface coated with nitrogen-doped carbon layer and MoS2 nanoparticles. Chitosan not only reacts with MoO4 through its protonated amino groups, but also 2- The electrostatic interaction and hydrogen bonding generated by the pre-treated silicon carbide promote the uniform compounding of the material. The nitrogen-doped carbon layer formed after carbonization can also effectively improve the dispersibility of the modified silicon carbide and the antistatic properties of the material. At the same time, the MoS2 nanoparticles generated on the surface of the modified silicon carbide can significantly enhance the wear resistance of the material. In addition, the inherent high hardness and high elastic modulus of silicon carbide provide mechanical support for the material. The nitrogen-doped carbon layer formed by surface modification can enhance its interaction with the polyurethane matrix, thereby improving the interfacial bonding strength between the two. At the same time, the MoS2 nanoparticles uniformly coated on the surface synergistically improve the overall mechanical properties of the material through the nano-enhancement effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is the SEM image of the modified silicon carbide prepared in Example 1. DETAILED DESCRIPTION

[0022] The technical solution of the present invention will be further described below in conjunction with specific embodiments. However, it should be understood by those skilled in the art that the following examples are only intended to illustrate the present invention and should not be construed as limiting the present invention. Specific conditions not specified in the examples are to be followed according to conventional conditions or the conditions recommended by the manufacturer. All reagents or instruments used, unless otherwise specified, are conventional products obtained from commercial channels.

[0023] The surfactant Pluronic P123 in the present invention is a trade name of an amphiphilic nonionic polymer surfactant, also known as P123, and its full name is polyvinyl ether-polypropylene ether-polyvinyl ether triblock copolymer (PEO-PPO-PEO, EO 20 PO 70 EO 20 ), CAS No. 9003-11-6; the dispersant is RL16, a derivative of fatty acid amide and fatty soap, with good internal and external lubrication effects.

[0024] Example 1 A high-strength cable sheath material comprises the following raw materials in parts by weight: 65 parts of polyether thermoplastic polyurethane with a hardness of 80A, 2 parts of dispersant RL16, 2 parts of antioxidant 1010, 12 parts of flame retardant, and 3 parts of modified silicon carbide.

[0025] The modified silicon carbide is prepared by the following preparation process: (1) Silicon carbide powder was added to a 30 wt% hydrogen peroxide solution at a dosage ratio of 0.9 g:100 mL and ultrasonically dispersed for 1 h. The solution was then reacted in a water bath at 80 °C for 6 h. After the reaction, the solution was centrifuged, and the collected solid was washed with ethanol and then dried in a vacuum oven at 80 °C to obtain pretreated silicon carbide powder.

[0026] (2) Chitosan, surfactant (Pluronic P123), acetic acid, Na2MoO4, CH4N2S, deionized water, and pretreated silicon carbide powder were added to deionized water in a ratio of 0.4 g: 0.42 g: 0.95 g: 0.11 g: 0.32 g: 60 mL: 1 g. Chitosan, surfactant Pluronic P123, and acetic acid were added to deionized water and stirred for 1.5 h. Na2MoO4 and CH4N2S were then added and stirred for 1.5 h to obtain a precursor solution. The pretreated silicon carbide powder obtained in step (1) was added to the precursor solution and reacted under hydrothermal conditions at 220°C for 26 h. The solid was filtered, washed with water, dried, and then carbonized at 680°C in a nitrogen atmosphere for 1.5 h to obtain modified silicon carbide. The SEM image of the modified silicon carbide is shown in FIG. Figure 1 As shown, it can be seen that the surface of the modified silicon carbide is covered with a rough nanosheet structure.

[0027] The flame retardant is prepared by the following preparation process: (a) A 0.3 mol / L ethanol solution of 5-hydroxy-1-naphthaldehyde was slowly added dropwise to a 0.25 mol / L ethanol solution of 1,10-phenanthroline-3,8-diamine, wherein the molar ratio of 5-hydroxy-1-naphthaldehyde to 1,10-phenanthroline-3,8-diamine was 2.2:1, and then the mixture was reacted at 70°C under an inert gas atmosphere for 5 h. After the reaction, the reaction solution was cooled to room temperature and filtered. The collected solid was washed with anhydrous ethanol and then dried in a vacuum oven at 60°C for 24 h to obtain intermediate 1 (yield 76.8%). 1 HNMR: (C 34 H 22N4O2, 400MHz, DMSO-d6) δ: 9.00(s,2H), 8.71(s, 2H), 8.58-8.54(dd, 2H), 8.52(s, 2H), 8.49-8.45(dd, 2H), 8.41(s,2H), 8.02-7.95(m, 4H), 7.50-7.42(m, 4H), 6.30-6.26(dd, 2H); HRMS (ESI + ): [M+H] + The calculation is 519.17, and the result is 519.17.

[0028] (b) Intermediate 1 and DOPO were added to anhydrous ethanol at a ratio of 0.01 mol: (0.022) mol: 180 mL of intermediate 1, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO), and anhydrous ethanol, and the mixture was refluxed under an inert gas atmosphere for 2.5 d. The reaction solution was cooled to room temperature and transferred to dichloromethane, and the product was precipitated with anti-solvent ethanol. The solid product was filtered to obtain a solid product, which was then dried in a vacuum oven at 60°C for 24 h to obtain a flame retardant (yield 57.4%). 1 HNMR: (C 58 H 40 N4O6P2, 400MHz, DMSO-d6) δ: 8.81(s, 2H), 8.41(s, 2H), 8.20-8.16(dd, 2H), 8.02-7.98(dd, 2H), 7.81(s, 2H), 7.76-7.73(d, 2H), 7.57-7.29(m,18H), 7.07(s, 2H), 6.98-6.94(dd, 2H), 6.79(s, 2H), 6.23-6.19(dd, 2H), 3.90(d,2H); HRMS (ESI + ): [M+H] + Calculated to be 951.24, found to be 951.24.

[0029] This embodiment also provides a method for preparing the above-mentioned high-strength cable sheath material, the steps of which are as follows: According to the above-mentioned parts by weight, polyether thermoplastic polyurethane, dispersant RL16, antioxidant 1010, flame retardant and modified silicon carbide are added to a high-speed mixer and mixed evenly, and then added to a twin-screw extruder, melt-extruded and granulated to obtain a cable waterproof and corrosion-resistant sheath material; wherein the temperature zones 1 to 10 of the twin-screw extruder are set as follows: 150°C, 160°C, 170°C, 180°C, 185°C, 185°C, 190°C, 195°C, 200°C, 200°C.

[0030] Example 2 A high-strength cable sheath material comprises the following raw materials in parts by weight: 50 parts of polyether thermoplastic polyurethane with a hardness of 80A, 1 part of dispersant RL16, 1 part of antioxidant 1024, 10 parts of flame retardant, and 1 part of modified silicon carbide.

[0031] The modified silicon carbide is prepared by the following preparation process: (1) Silicon carbide powder was added to a 30 wt% hydrogen peroxide solution at a dosage ratio of 0.8 g:100 mL and ultrasonically dispersed for 0.5 h. The solution was then reacted in a 75 °C water bath for 8 h. After the reaction, the solution was centrifuged, the collected solid was washed with ethanol, and then dried in a vacuum oven at 80 °C to obtain pretreated silicon carbide powder.

[0032] (2) Chitosan, surfactant Pluronic P123 and acetic acid were added to deionized water and stirred for 1 h, and then Na2MoO4 and CH4N2S were added and stirred for 1 h to obtain a precursor solution. The pretreated silicon carbide powder obtained in step (1) was added to the precursor solution and reacted under hydrothermal conditions at 210°C for 30 h. The collected solid was filtered, washed with water, dried, and then carbonized at 650°C in a nitrogen atmosphere for 1.5 h to obtain modified silicon carbide.

[0033] The flame retardant is prepared by the following preparation process, and the reaction flow is the same as that in Example 1: (a) A 0.2 mol / L ethanol solution of 5-hydroxy-1-naphthaldehyde was slowly added dropwise to a 0.3 mol / L ethanol solution of 1,10-phenanthroline-3,8-diamine, wherein the molar ratio of 5-hydroxy-1-naphthaldehyde to 1,10-phenanthroline-3,8-diamine was 2:1, and then the mixture was reacted at 60°C under an inert gas atmosphere for 6 h. After the reaction, the reaction solution was cooled to room temperature and filtered. The collected solid was washed with anhydrous ethanol and then dried in a vacuum oven at 60°C for 24 h to obtain intermediate 1 (yield 77.2%). 1 HNMR and HRMS (ESI + ) is consistent with Example 1.

[0034] (b) Intermediate 1 and DOPO were added to anhydrous ethanol at a ratio of 0.01 mol:0.02 mol:150 mL, and the mixture was refluxed under an inert gas atmosphere for 2 d. The reaction solution was cooled to room temperature and transferred to dichloromethane, and the product was precipitated with anti-solvent ethanol. The solid product was filtered and dried in a vacuum oven at 60°C for 24 h to obtain a flame retardant (yield 59.0%). 1 HNMR and HRMS (ESI + ) is consistent with Example 1.

[0035] This embodiment also provides a method for preparing the above-mentioned high-strength cable sheath material, and the specific steps are the same as those in Example 1.

[0036] Example 3 A high-strength cable sheath material comprises the following raw materials in parts by weight: 80 parts of polyether thermoplastic polyurethane with a hardness of 80A, 3 parts of dispersant RL16, 3 parts of antioxidant 168, 15 parts of flame retardant, and 5 parts of modified silicon carbide.

[0037] The modified silicon carbide is prepared by the following preparation process: (1) Silicon carbide powder was added to a 30 wt% hydrogen peroxide solution at a dosage ratio of 1 g:100 mL and ultrasonically dispersed for 1 h. The solution was then reacted in a water bath at 85 °C for 5 h. After the reaction, the solution was centrifuged, and the collected solids were washed with ethanol and then dried in a vacuum oven at 80 °C to obtain pretreated silicon carbide powder.

[0038] (2) Chitosan, surfactant (Pluronic P123), acetic acid, Na2MoO4, CH4N2S, deionized water, and pretreated silicon carbide powder were added to deionized water in a ratio of 0.6 g: 0.45 g: 1.0 g: 0.15 g: 0.35 g: 65 mL: 1 g. Chitosan, surfactant Pluronic P123, and acetic acid were added to deionized water and stirred for 2 h. Na2MoO4 and CH4N2S were then added and stirred for 2 h to obtain a precursor solution. The pretreated silicon carbide powder obtained in step (1) was added to the precursor solution and reacted under hydrothermal conditions at 230 °C for 22 h. The solid was filtered, washed with water, dried, and then carbonized under nitrogen atmosphere at 700 °C for 1 h to obtain modified silicon carbide.

[0039] The flame retardant is prepared by the following preparation process, and the reaction flow is the same as that in Example 1: (a) A 0.4 mol / L ethanol solution of 5-hydroxy-1-naphthaldehyde was slowly added dropwise to a 0.2 mol / L ethanol solution of 1,10-phenanthroline-3,8-diamine, wherein the molar ratio of 5-hydroxy-1-naphthaldehyde to 1,10-phenanthroline-3,8-diamine was 2.5:1, and then the mixture was reacted at 75°C under an inert gas atmosphere for 4 h. After the reaction, the reaction solution was cooled to room temperature and filtered. The collected solid was washed with anhydrous ethanol and then dried in a vacuum oven at 60°C for 24 h to obtain intermediate 1 (yield 75.9%). 1 HNMR and HRMS (ESI + ) is consistent with Example 1.

[0040] (b) Intermediate 1 and DOPO were added to anhydrous ethanol at a ratio of 0.01 mol:0.025 mol:200 mL, and the mixture was refluxed under an inert gas atmosphere for 3 days. The reaction solution was cooled to room temperature and transferred to dichloromethane. The product was then precipitated with anti-solvent ethanol, filtered to obtain a solid product, and then dried in a vacuum oven at 60°C for 24 hours to obtain a flame retardant (yield 56.6%). 1 HNMR and HRMS (ESI + ) is consistent with Example 1.

[0041] This embodiment also provides a method for preparing the above-mentioned high-strength cable sheath material, and the specific steps are the same as those in Example 1.

[0042] Comparative Example 1 Comparative Example 1 is substantially the same as Example 1, except that the flame retardant in Example 1 is replaced by DOPO.

[0043] Comparative Example 2 Comparative Example 2 is substantially the same as Example 1, except that the modified silicon carbide in Example 1 is replaced by a simple mixture of silicon carbide, chitosan, and molybdenum disulfide, wherein the amounts of silicon carbide, chitosan, and molybdenum disulfide are the same as those in Example 1.

[0044] Test example The performance test of the cable sheath materials prepared in Examples 1-3 and Comparative Examples 1-2 was carried out as follows: (1) Mechanical properties: The tensile strength and elongation at break of the cable sheath materials prepared in Examples 1-3 and Comparative Examples 1-2 were measured in accordance with GB / T 2951.11-2008 General test methods for insulation and sheathing materials of electric and optical cables Part 11: General test methods for thickness and dimensions - Mechanical properties test. (2) Wear resistance: The mass wear of the cable sheath materials prepared in Examples 1-3 and Comparative Examples 1-2 was measured in accordance with GB / T 3960-2016 “Test method for sliding friction and wear of plastics”; (3) Flame retardant properties: The oxygen index of the cable sheath materials prepared in Examples 1-3 and Comparative Examples 1-2 was measured in accordance with GB / T 2406.2-2009 “Determination of combustion behavior of plastics by oxygen index method Part 2: Room temperature test”; (4) Antistatic properties: The surface resistivity of the cable sheath materials prepared in Examples 1-3 and Comparative Examples 1-2 was measured according to ASTM D4496-21e1. The above test results are shown in Table 1.

[0045] Table 1 It can be seen from Table 1 that the cable sheath materials prepared in Examples 1-3 of the present invention have excellent mechanical properties, wear resistance, flame retardancy and antistatic capabilities.

[0046] Compared with Example 1, in Comparative Example 1, the flame retardant of the present invention is replaced with unmodified DOPO, and the tensile strength, elongation at break and oxygen index are reduced. This shows that the flame retardant prepared by the present invention not only affects the flame retardant properties of the cable sheath material, but also has a certain effect on the mechanical properties of the material. This is because the hydroxyl group in the flame retardant molecule of the present invention can form a strong hydrogen bond network with -NH-CO-O- in the polyurethane, or form a covalent bond with the isocyanate group in the polyurethane to improve its compatibility and dispersibility, and enhance the interfacial bonding strength, thereby avoiding the problem of traditional inorganic flame retardants or blended flame retardant plastics causing a decrease in the mechanical properties of the material.

[0047] Compared with Example 1, Comparative Example 2 replaces the modified silicon carbide in Example 1 with a simple mixture of silicon carbide, chitosan, and molybdenum disulfide. The tensile strength, elongation at break, and surface resistivity of the material are significantly reduced, and the mass wear is significantly increased. This shows that the addition of modified silicon carbide can significantly improve the mechanical properties of the cable sheath material, while also improving its wear resistance and antistatic ability. Silicon carbide is pretreated to obtain hydroxylated silicon carbide, and then a chitosan-assisted hydrothermal method and carbonization treatment are used to form a modified silicon carbide with a surface coated with a nitrogen-doped carbon layer and MoS2 nanoparticles. Chitosan not only reacts with MoO4 through its protonated amino groups, but also improves the mechanical properties of the cable sheath material. 2- The electrostatic interaction and hydrogen bonding generated by the pre-treated silicon carbide promote the uniform compounding of the material. The nitrogen-doped carbon layer formed after carbonization can also effectively improve the dispersibility of the modified silicon carbide and the antistatic properties of the material. At the same time, the MoS2 nanoparticles generated on the surface of the modified silicon carbide can significantly enhance the wear resistance of the material. In addition, the inherent high hardness and high elastic modulus of silicon carbide provide mechanical support for the material. The nitrogen-doped carbon layer formed by surface modification can enhance its interaction with the polyurethane matrix, thereby improving the interfacial bonding strength between the two. At the same time, the MoS2 nanoparticles uniformly coated on the surface synergistically improve the overall mechanical properties of the material through the nano-enhancement effect.

[0048] Finally, it should be noted that the above embodiments are intended only to illustrate the technical solutions of the present invention and are not intended to limit the same. The basic principles and main features of the present invention have been described above using specific implementation schemes. Modifications or substitutions may be made based on the present invention, but such modifications or substitutions do not detract from the essence of the corresponding technical solutions from the scope of protection claimed by the present invention.

Claims

1. A high-strength cable sheath material, characterized in that: The invention comprises the following raw materials in parts by weight: 50-80 parts of polyurethane, 1-3 parts of dispersant, 1-3 parts of antioxidant, 10-15 parts of flame retardant, and 1-5 parts of modified silicon carbide; The modified silicon carbide is prepared by the following preparation process: (1) dispersing silicon carbide powder into hydrogen peroxide solution, reacting under heating conditions, centrifuging after the reaction, washing and drying the collected product to obtain pretreated silicon carbide powder; (2) Add chitosan, surfactant, and acetic acid into water and stir, then add sodium molybdate and thiourea and continue stirring to obtain a precursor solution; The pretreated silicon carbide powder obtained in step (1) is added to the precursor solution to carry out a hydrothermal reaction, and the mixture is filtered. The collected product is washed, dried, and carbonized to obtain the modified silicon carbide.

2. The high-strength cable sheath material according to claim 1, characterized in that: In step (1), the amount ratio of silicon carbide powder to hydrogen peroxide solution is (0.8-1) g: 100 mL; the heating temperature is 75-85° C., and the reaction time is 5-8 h.

3. The high-strength cable sheath material according to claim 1, characterized in that: The mass ratio of chitosan, surfactant, acetic acid, sodium molybdate, thiourea and pretreated silicon carbide powder in step (2) is (3-6): (4-4.5): (9-10): (1-1.5): (3-3.5): 10; the surfactant is a polyethylene ether-polypropylene ether-polyethylene ether triblock copolymer; the stirring time is 1-2 h; and the continued stirring time is 1-2 h.

4. The high-strength cable sheath material according to claim 1, characterized in that: The temperature of the hydrothermal reaction in step (2) is 210-230°C, and the time is 22-30 h; the temperature of the carbonization is 650-700°C, and the time is 1-1.5 h.

5. The high-strength cable sheath material according to claim 1, characterized in that: The preparation process of the flame retardant is as follows: (a) adding an ethanol solution of 5-hydroxy-1-naphthaldehyde to an ethanol solution of 1,10-phenanthroline-3,8-diamine, and reacting under an inert gas atmosphere and heating; after the reaction, cooling the reaction solution to room temperature, filtering, and washing and drying the collected solid to obtain intermediate 1; (b) adding the intermediate 1 and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide to ethanol and subjecting them to reflux reaction under an inert gas atmosphere; after the reaction is completed, the flame retardant is obtained by purification.

6. The high-strength cable sheath material according to claim 5, characterized in that: The molar ratio of 5-hydroxy-1-naphthaldehyde to 1,10-phenanthroline-3,8-diamine in step (a) is (2-2.5):1; the concentration of the ethanol solution of 5-hydroxy-1-naphthaldehyde is 0.2-0.4 mol / L; the concentration of the ethanol solution of 1,10-phenanthroline-3,8-diamine is 0.2-0.3 mol / L; the heating temperature is 60-75° C., and the reaction time is 4-6 h.

7. The high-strength cable sheath material according to claim 5, characterized in that: In step (b), the molar ratio of the intermediate 1 to 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide is 1:(2-2.5); and the reflux reaction time is 2-3 days.

8. The high-strength cable sheath material according to claim 1, characterized in that: The polyurethane is polyether thermoplastic polyurethane with a hardness of 75-85A; the dispersant is RL16; and the antioxidant is at least one of antioxidant 1010, antioxidant 1024, and antioxidant 168.

9. The method for preparing the high-strength cable sheath material according to any one of claims 1 to 8, characterized in that: The following steps are involved: The polyurethane, dispersant, antioxidant, flame retardant and modified silicon carbide are uniformly mixed according to the weight proportions, and then melt-extruded and granulated to obtain a waterproof and corrosion-resistant cable sheath material.

10. Use of the high-strength cable sheath material according to any one of claims 1 to 8 in the preparation of cable sheaths.

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