A high-strength cable sheath material and a method for producing and using the same

Abstract

The application 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: polyurethane 50-80 parts, dispersant 1-3 parts, antioxidant 1-3 parts, flame retardant 10-15 parts, and modified silicon carbide 1-5 parts. The high-strength cable sheath material is obtained by adding flame retardant, modified silicon carbide, dispersant, antioxidant and other components into polyurethane, and the cable sheath material has excellent mechanical properties, wear resistance, flame retardance and antistatic capacity.

Description

TECHNICAL FIELD

[0001] The application 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. BACKGROUND

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

[0003] However, with the wide application of power cables in new energy, rail transit and other high-voltage and high-current scenarios, TPU as a cable sheath material faces severe performance challenges. There are many problems in the actual application of traditional TPU cable sheath materials: on the one hand, the flexible characteristics of TPU molecular chains make it difficult to meet the mechanical protection requirements of high-voltage cables in terms of tensile strength and wear resistance; on the other hand, the limiting oxygen index of TPU is much lower than the flame-retardant standard of cables, and it produces melt dripping phenomenon when burning, which poses a major threat to people, property and the environment. In addition, the existing technology usually adopts the scheme of adding inorganic flame retardants (such as aluminum hydroxide) or physically blending flame-retardant plastics, but these methods will cause the elongation at break of the material to decrease and cause interface compatibility problems. Therefore, it is necessary to improve the thermoplastic polyurethane-based cable sheath material to solve the above problems. SUMMARY

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

[0005] Another purpose of the present application is to provide a preparation method of the above-mentioned high-strength cable sheath material.

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

[0007] The purposes of the present application are achieved by the following technical solutions:

[0008] A high-strength cable sheath material comprises the following raw materials in parts by weight: polyurethane 50-80 parts, dispersing agent 1-3 parts, antioxidant 1-3 parts, flame retardant 10-15 parts, and modified silicon carbide 1-5 parts.

[0009] The modified silicon carbide is prepared by the following preparation process:

[0010] (1) dispersing silicon carbide powder into hydrogen peroxide solution, reacting under heating condition, centrifuging after reaction, washing and drying the collected product to obtain pretreated silicon carbide powder;

[0011] (2) adding chitosan, surfactant and acetic acid into water and stirring, then adding sodium molybdate and thiourea and continuing to stir to obtain a precursor solution; adding the pretreated silicon carbide powder obtained in step (1) into the precursor solution to perform hydrothermal reaction, filtering, washing and drying the collected product, carbonizing to obtain the modified silicon carbide.

[0012] Further, in step (1), the mass ratio of the silicon carbide powder to hydrogen peroxide solution is (0.8-1) g:100 mL; the heating temperature is 75-85℃, and the reaction time is 5-8 h.

[0013] Further, 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 polyethylene ether-polypropylene ether-polyethylene ether triblock copolymer; the stirring time is 1-2 h; and the continuing stirring time is 1-2 h.

[0014] Further, in step (2), the hydrothermal reaction temperature is 210-230℃, and the time is 22-30 h; and the carbonization temperature is 650-700℃, and the time is 1-1.5 h.

[0015] Further, the preparation process of the flame retardant is as follows:

[0016]

[0017] (a) adding 5-hydroxy-1-naphthaldehyde ethanolic solution into 1,10-phenanthroline-3,8-diamine ethanolic solution, and reacting under inert gas atmosphere and heating condition; after reaction, cooling the reaction liquid to room temperature, filtering, washing and drying the collected solid to obtain intermediate 1;

[0018] (b) adding the intermediate 1 and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide into ethanol, and refluxing under inert gas atmosphere; after reaction, performing purification treatment to obtain the flame retardant.

[0019] The application utilizes 5-hydroxy-1-naphthaldehyde and 1,10-phenanthroline-3,8-diamine to modify 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) to obtain a flame retardant.The flame retardant mechanism of the flame retardant includes three aspects: ① gas phase flame retardation: the phosphaphenanthrene structure in the flame retardant can decompose to generate PO· free radicals at high temperature, and then capture H· and OH· active free radicals in the combustion chain reaction; the phenanthroline-naphthaldehyde skeleton can promote charring to form a dense carbon layer to isolate oxygen and heat; ② condensed phase flame retardation: the phosphorus element in the flame retardant can promote the dehydration and carbonization of the polymer matrix to form an expanded carbon layer; and a large number of aromatic ring structures can provide high thermal stability, and the hydroxyl and nitrogen atoms can synergistically promote the cross-linking and carbonization reaction; ③ physical barrier effect: the large conjugated plane structure in the flame retardant can form a physical barrier layer in the material, and generate inert gases (CO2, N2) to dilute combustible gases during decomposition.

[0020] Further, in step (a), the molar ratio of the 5-hydroxy-1-naphthaldehyde to the 1,10-phenanthroline-3,8-diamine is (2-2.5):1; the concentration of the ethanol solution of the 5-hydroxy-1-naphthaldehyde is 0.2-0.4 mol / L; the concentration of the ethanol solution of the 1,10-phenanthroline-3,8-diamine is 0.2-0.3 mol / L; the heating temperature is 60-75℃, and the reaction time is 4-6 h.

[0021] Further, in step (b), the molar ratio of the intermediate 1 to the 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide is 1:(2-2.5); and the reflux reaction time is 2-3 d.

[0022] Further, the polyurethane is a polyether type 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.

[0023] The preparation method of the high-strength cable sheath material includes the following steps:

[0024] According to the weight parts, the polyurethane, the dispersant, the antioxidant, the flame retardant and the modified silicon carbide are uniformly mixed, and then melt-extruded and granulated to obtain the cable waterproof and corrosion-resistant sheath material.

[0025] The high-strength cable sheath material is applied to the preparation of a cable sheath.

[0026] Compared with the prior art, the application has the following effects:

[0027] 1. The present application obtains a high-strength cable sheath material by adding flame retardant, modified silicon carbide, dispersant and antioxidant and other components into polyurethane, which has excellent mechanical properties, wear resistance, flame retardance and antistatic ability.

[0028] 2. The flame retardant of the present application can not only significantly improve the flame retardance of the cable sheath material, but also improve the compatibility and dispersibility of the flame retardant and enhance the interfacial bonding strength by forming a strong hydrogen bond network with -NH-CO-O- in polyurethane or forming a covalent bond with isocyanate groups in polyurethane through the hydroxyl groups in the flame retardant molecules.

[0029] 3. The present application significantly improves the mechanical properties of the cable sheath material by adding modified silicon carbide as a reinforcing agent, and also improves its wear resistance and antistatic ability. Silicon carbide is hydroxylated by pretreatment, and then modified silicon carbide with a surface coated with a nitrogen-doped carbon layer and MoS2 nanoparticles is formed by a chitosan-assisted hydrothermal method and carbonization treatment. Chitosan not only promotes the uniform compounding of the material through electrostatic interaction and hydrogen bonding between the protonated amino groups of chitosan and MoO4 2- and pretreated silicon carbide, but also effectively improves the dispersibility of the modified silicon carbide and the antistatic performance of the material. In addition, the MoS2 nanoparticles generated on the surface of the modified silicon carbide can significantly enhance the wear resistance of the material. Moreover, the inherent high hardness and high elastic modulus of silicon carbide provide mechanical support for the material, and the nitrogen-doped carbon layer formed by surface modification can enhance the interaction between the material and the polyurethane matrix, thereby improving the interfacial bonding strength between the two. Meanwhile, the MoS2 nanoparticles uniformly coated on the surface can synergistically improve the overall mechanical properties of the material through nano-enhancing effect. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 SEM image of the modified silicon carbide prepared in Example 1. DETAILED DESCRIPTION

[0031] The technical solutions of the present application are further described below in conjunction with the specific embodiments. However, those skilled in the art should understand that the following examples are only used to illustrate the present application and should not be regarded as limiting the present application. The specific conditions not mentioned in the examples are carried out according to the conventional conditions or the conditions recommended by the manufacturer. The reagents or instruments used, if not specifically mentioned, are conventional products obtained through market channels.

[0032] The surfactant Pluronic P123 in the present application is a trade name of an amphiphilic non-ionic high molecular surfactant, also known as P123, and its full name is polyethylene ether-polypropylene ether-polyethylene ether triblock copolymer (PEO-PP0-PEO, EO 20 PO 70 EO20 ), CAS No. 9003-11-6; the dispersant is RL16, which is a derivative of fatty acid amide and fatty soap, and has good internal lubrication and external lubrication effect.

[0033] Example 1

[0034] A high-strength cable sheath material, comprising the following raw materials in parts by weight: polyether thermoplastic polyurethane with a hardness of 80A 65 parts, dispersant RL16 2 parts, antioxidant 1010 2 parts, flame retardant 12 parts, modified silicon carbide 3 parts.

[0035] The above-mentioned modified silicon carbide is prepared by the following preparation process:

[0036] (1) According to the amount ratio of 0.9 g: 100 mL, the silicon carbide powder is added to the hydrogen peroxide solution with a concentration of 30 wt% for ultrasonic dispersion for 1 h, and then reacted in a water bath at 80℃ for 6 h; after the reaction is completed, centrifugal, the collected solid is washed with ethanol, and then dried in a vacuum oven at 80℃ to obtain the pretreated silicon carbide powder.

[0037] (2) According to the amount ratio of chitosan, surfactant (Pluronic P123), acetic acid, Na2MoO4, CH4N2S and deionized water, pretreated silicon carbide powder is 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 are added to deionized water and stirred for 1.5 h, then Na2MoO4 and CH4N2S are added and continue to stir for 1.5 h to obtain a precursor solution; the pretreated silicon carbide powder obtained in step (1) is added to the precursor solution, and reacted under hydrothermal conditions at 220℃ for 26 h; filter, wash and dry the collected solid with water, then carbonize under nitrogen atmosphere at 680℃ for 1.5 h to obtain the modified silicon carbide, the SEM image of the modified silicon carbide is shown in Figure 1 , it can be seen that the surface of the modified silicon carbide is covered by rough nanosheet layer structure.

[0038] The above-mentioned flame retardant is prepared by the following preparation process:

[0039]

[0040] (a) A 0.3 mol / L solution of 5-hydroxy-1-naphthaldehyde in ethanol was slowly added to a 0.25 mol / L solution of 1,10-phenanthroline-3,8-diamine in ethanol, with a molar ratio of 5-hydroxy-1-naphthaldehyde to 1,10-phenanthroline-3,8-diamine of 2.2:1, and then reacted at 70°C for 5 h under an inert gas atmosphere; after the reaction was completed, the reaction solution was cooled to room temperature, filtered, and 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 (a yield of 76.8%); the intermediate 1 was used in the next step without further purification. 1 HNMR: (CDCI3, 400 MHz, 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 34 H 22 N4O2, 400 MHz, 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] + Calculated 519.17, Found 519.17.

[0041] (b) According to the amount ratio of intermediate 1, 9,10-dihydro-9-oxa-10- phosphaphenanthrene-10-oxide (DOPO), and anhydrous ethanol of 0.01 mol:(0.022) mol:180 mL, the intermediate 1 and DOPO were added to anhydrous ethanol and reacted under reflux for 2.5 d under an inert gas atmosphere; the reaction solution was cooled to room temperature and transferred to dichloromethane, and then the product was precipitated with anti-solvent ethanol, filtered to obtain a solid product, and then dried in a vacuum oven at 60°C for 24 h to obtain a flame retardant (a yield of 57.4%); the flame retardant was used in the next step without further purification. 1 HNMR: (CDCI3, 400 MHz, 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 58 H 40 N4O6P2, 400 MHz, 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]+ Calculated 951.24, found 951.24.

[0042] The embodiment also provides a preparation method of the high-strength cable sheath material, and the steps are as follows:

[0043] According to the above weight parts, the polyether type thermoplastic polyurethane, dispersant RL16, antioxidant 1010, flame retardant and modified silicon carbide are uniformly mixed in a high-speed mixer, and then are added into a double-screw extruder for melt extrusion and granulation to obtain the waterproof and corrosion-resistant cable sheath material; wherein the temperature of the double-screw extruder is set as follows: 150℃, 160℃, 170℃, 180℃, 185℃, 185℃, 190℃, 195℃, 200℃, 200℃.

[0044] Example 2

[0045] A high-strength cable sheath material, comprising the following raw materials in weight parts: polyether type thermoplastic polyurethane with a hardness of 80A 50 parts, dispersant RL16 1 part, antioxidant 1024 1 part, flame retardant 10 parts, modified silicon carbide 1 part.

[0046] The modified silicon carbide is prepared by the following preparation process:

[0047] (1) According to the amount ratio of 0.8 g: 100 mL, the silicon carbide powder is added to the hydrogen peroxide solution with a concentration of 30 wt% for ultrasonic dispersion for 0.5 h, and then is reacted in a 75℃ water bath for 8 h; after the reaction is completed, centrifugation is performed, the collected solid is washed with ethanol, and then is dried in a 80℃ vacuum oven to obtain the pretreated silicon carbide powder.

[0048] (2) According to the amount ratio of chitosan, Pluronic P123, acetic acid, Na2MoO4, CH4N2S and deionized water, pretreated silicon carbide powder of 0.3 g: 0.4 g: 0.9 g: 0.1 g: 0.3 g: 60 mL: 1 g, the chitosan, surfactant Pluronic P123 and acetic acid are added to the deionized water and stirred for 1 h, then Na2MoO4 and CH4N2S are added and continue to stir for 1 h to obtain a precursor solution; the pretreated silicon carbide powder obtained in step (1) is added to the precursor solution, and is reacted under hydrothermal conditions at 210℃ for 30 h; filtration is performed, the collected solid is washed with water and dried, and then is carbonized under the conditions of nitrogen atmosphere and 650℃ for 1.5 h to obtain the modified silicon carbide.

[0049] The flame retardant is prepared by the following preparation process, and the reaction flow chart is the same as that of Example 1:

[0050] (a) A 0.2 mol / L solution of 5-hydroxy-1-naphthaldehyde in ethanol was slowly added to a 0.3 mol / L solution of 1,10-phenanthroline-3,8-diamine in ethanol, with a molar ratio of 5-hydroxy-1-naphthaldehyde to 1,10-phenanthroline-3,8-diamine of 2:1, and then reacted at 60°C for 6 h under an inert gas atmosphere; after the reaction was completed, the reaction solution was cooled to room temperature, filtered, and 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 (a yield of 77.2%); the intermediate 1 was then reacted with 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) in anhydrous ethanol according to a ratio of 0.01 mol:0.02 mol:150 mL, and then reacted at reflux for 2 d under an inert gas atmosphere; the reaction solution was cooled to room temperature and transferred to dichloromethane, and then the product was precipitated with an anti-solvent of ethanol, filtered to obtain a solid product, and then dried in a vacuum oven at 60°C for 24 h to obtain a flame retardant (a yield of 59.0%); the flame retardant was then reacted with 2,2-bis(hydroxymethyl)propionic acid according to a ratio of 0.01 mol:0.02 mol:150 mL, and then reacted at reflux for 2 d under an inert gas atmosphere; the reaction solution was cooled to room temperature and transferred to dichloromethane, and then the product was precipitated with an anti-solvent of ethanol, filtered to obtain a solid product, and then dried in a vacuum oven at 60°C for 24 h to obtain a flame-retardant cable sheath material (a yield of 59.0%). 1 HNMR and HRMS (ESI + ) were consistent with those of Example 1.

[0051] (a) A 0.2 mol / L solution of 5-hydroxy-1-naphthaldehyde in ethanol was slowly added to a 0.3 mol / L solution of 1,10-phenanthroline-3,8-diamine in ethanol, with a molar ratio of 5-hydroxy-1-naphthaldehyde to 1,10-phenanthroline-3,8-diamine of 2:1, and then reacted at 60°C for 6 h under an inert gas atmosphere; after the reaction was completed, the reaction solution was cooled to room temperature, filtered, and 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 (a yield of 77.2%); the intermediate 1 was then reacted with 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) in anhydrous ethanol according to a ratio of 0.01 mol:0.02 mol:150 mL, and then reacted at reflux for 2 d under an inert gas atmosphere; the reaction solution was cooled to room temperature and transferred to dichloromethane, and then the product was precipitated with an anti-solvent of ethanol, filtered to obtain a solid product, and then dried in a vacuum oven at 60°C for 24 h to obtain a flame retardant (a yield of 59.0%); the flame retardant was then reacted with 2,2-bis(hydroxymethyl)propionic acid according to a ratio of 0.01 mol:0.02 mol:150 mL, and then reacted at reflux for 2 d under an inert gas atmosphere; the reaction solution was cooled to room temperature and transferred to dichloromethane, and then the product was precipitated with an anti-solvent of ethanol, filtered to obtain a solid product, and then dried in a vacuum oven at 60°C for 24 h to obtain a flame-retardant cable sheath material (a yield of 59.0%). 1 HNMR and HRMS (ESI + ) were consistent with those of Example 1.

[0052] The present embodiment also provides a preparation method of the above high-strength cable sheath material, and the specific steps are the same as those of Example 1.

[0053] Example 3

[0054] A high-strength cable sheath material comprises the following raw materials in parts by weight: polyether type thermoplastic polyurethane with a hardness of 80A 80 parts, dispersant RL16 3 parts, antioxidant 168 3 parts, flame retardant 15 parts, and modified silicon carbide 5 parts.

[0055] The above modified silicon carbide is prepared by the following preparation process:

[0056] (1) According to a ratio of 1 g:100 mL, silicon carbide powder was added to a 30 wt% hydrogen peroxide solution and ultrasonically dispersed for 1 h, and then reacted in a 85°C water bath for 5 h; after the reaction was completed, the collected solid was washed with ethanol and then dried in a vacuum oven at 80°C to obtain pretreated silicon carbide powder.

[0057] (2) According to the amount ratio of chitosan, surfactant (Pluronic P123), acetic acid, Na2MoO4, CH4N2S and deionized water, pretreated silicon carbide powder 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 are added into deionized water and stirred for 2 h, then Na2MoO4 and CH4N2S are added and stirred for 2 h to obtain a precursor solution; the pretreated silicon carbide powder obtained in step (1) is added into the precursor solution, and the mixture is reacted under hydrothermal conditions at 230°C for 22 h; the collected solid is washed with water and dried, and then carbonized under nitrogen atmosphere at 700°C for 1 h to obtain modified silicon carbide.

[0058] The above flame retardant is prepared by the following preparation process, and the reaction flow chart is the same as that of Example 1:

[0059] (a) A 0.4 mol / L 5-hydroxy-1-naphthaldehyde ethanol solution is slowly added to a 0.2 mol / L 1,10-phenanthroline-3,8-diamine ethanol solution, wherein the molar ratio of 5-hydroxy-1-naphthaldehyde and 1,10-phenanthroline-3,8-diamine is 2.5:1, and then reacted at 75°C under inert gas atmosphere for 4 h; after the reaction is completed, the reaction solution is cooled to room temperature, filtered, and the collected solid is washed with anhydrous ethanol and then dried in a vacuum oven at 60°C for 24 h to obtain intermediate 1 (yield 75.9%); the 1 HNMR and HRMS (ESI + ) of intermediate 1 are consistent with those of Example 1.

[0060] (b) According to the amount ratio of intermediate 1, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO), anhydrous ethanol of 0.01 mol: 0.025 mol: 200 mL, intermediate 1 and DOPO are added into anhydrous ethanol and refluxed under inert gas atmosphere for 3 d; the reaction solution is cooled to room temperature and transferred into dichloromethane, and then the product is precipitated with anti-solvent ethanol, filtered to obtain solid product, and then dried in a vacuum oven at 60°C for 24 h to obtain a flame retardant (yield 56.6%); the 1 HNMR and HRMS (ESI + ) of the flame retardant are consistent with those of Example 1.

[0061] The present embodiment also provides a preparation method of the above high-strength cable sheath material, and the specific steps are the same as those of Example 1.

[0062] Comparative Example 1

[0063] Comparative Example 1 is basically the same as Example 1, except that the flame retardant in Example 1 is replaced by DOPO.

[0064] Comparative Example 2

[0065] Comparative Example 2 is basically 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 in Example 1.

[0066] Test Example

[0067] The cable sheath materials prepared in Examples 1-3 and Comparative Examples 1-2 are subjected to performance tests, and the specific methods are as follows:

[0068] (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 are determined according to GB / T 2951.11-2008 "Cable and optical cable insulation and sheath materials General test methods Part 11: General test methods Thickness and outer dimension measurement Mechanical property test";

[0069] (2) Wear resistance: The mass wear of the cable sheath materials prepared in Examples 1-3 and Comparative Examples 1-2 is determined according to GB / T 3960-2016 "Plastics - Sliding friction and wear testing methods";

[0070] (3) Flame retardant properties: The oxygen index of the cable sheath materials prepared in Examples 1-3 and Comparative Examples 1-2 is determined according to GB / T 2406.2-2009 "Plastics - Determination of the flammability of plastics - Part 2: Test methods at room temperature";

[0071] (4) Antistatic properties: The surface resistivity of the cable sheath materials prepared in Examples 1-3 and Comparative Examples 1-2 is determined according to ASTM D4496-21e1 standard;

[0072] The test results are shown in Table 1.

[0073] Table 1

[0074]

[0075] As can be seen from Table 1, the cable sheath materials prepared in Examples 1-3 have excellent mechanical properties, wear resistance, flame retardant properties, and antistatic properties.

[0076] Compared with Example 1, the flame retardant of the present application is replaced by unmodified DOPO in Comparative Example 1, and the tensile strength, elongation at break and oxygen index are reduced, which shows that the flame retardant prepared by the present application not only affects the flame retardant performance of the cable sheath material, but also has a certain influence on the mechanical properties of the material, because the hydroxyl groups in the flame retardant molecules can form a strong hydrogen bond network with the -NH-CO-O- in the polyurethane, or form a covalent bond with the isocyanate groups in the polyurethane to improve the compatibility and dispersion, and enhance the interfacial bonding strength, thereby avoiding the problem of mechanical property reduction of the material caused by traditional inorganic flame retardants or blended flame retardant plastics.

[0077] Compared with Example 1, the modified silicon carbide in Example 1 is replaced by a simple mixture of silicon carbide, chitosan and molybdenum disulfide in Comparative Example 2, and the tensile strength, elongation at break and surface resistivity of the material are significantly reduced, and the mass wear is significantly increased, which shows that the addition of modified silicon carbide can significantly improve the mechanical properties of the cable sheath material, and also improve its wear resistance and antistatic ability. The silicon carbide is hydroxylated by pretreatment, and then the modified silicon carbide with a surface coated with nitrogen-doped carbon layer and MoS2 nanoparticles is formed by chitosan-assisted hydrothermal method and carbonization treatment. Chitosan not only promotes the uniform compounding of the material through the electrostatic interaction and hydrogen bonding between the protonated amino groups and MoO4 2- and the pretreated silicon carbide, but also effectively improves the dispersion of the modified silicon carbide and the antistatic performance of the material. In addition, 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, and the nitrogen-doped carbon layer formed by surface modification can enhance the interaction between the material and the polyurethane matrix, thereby improving the interfacial bonding strength between the two, and the uniformly coated MoS2 nanoparticles on the surface can synergistically improve the overall mechanical properties of the material through the nano-enhancing effect.

[0078] Finally, it should be pointed out that the above embodiments are only used to illustrate the technical solutions of the present application, but not to limit it. The basic principles and main features of the present application have been described above with specific embodiments, and some modifications or replacements can be made on the basis of the present application, but these modifications or replacements do not make the corresponding technical solutions deviate from the scope of the present application.

Claims

1. A high strength cable jacket material characterized in that, The raw materials include the following components in parts by weight: polyurethane 50-80 parts, dispersing agent 1-3 parts, antioxidant 1-3 parts, flame retardant 10-15 parts, modified silicon carbide 1-5 parts; The structural formula of the flame retardant is as follows: ； The modified silicon carbide is prepared by the following process: (1) The silicon carbide powder is dispersed into hydrogen peroxide solution, and reacted under heating condition. After the reaction is completed, centrifugal separation is performed, and the collected product is washed and dried to obtain pretreated silicon carbide powder; (2) Chitosan, a surfactant, and acetic acid are stirred in water, and then sodium molybdate and thiourea are added and stirred to obtain a precursor solution; The pretreated silicon carbide powder obtained in step (1) is added to the precursor solution for hydrothermal reaction, and the collected product is washed, dried, and carbonized to obtain the modified silicon carbide.

2. The high strength cable jacket material of claim 1, wherein, 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℃, and the reaction time is 5-8 h.

3. The high strength cable jacket material of claim 1, wherein, 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 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 jacket material of claim 1, wherein, In step (2), the hydrothermal reaction temperature is 210-230℃, and the time is 22-30 h; and the carbonization temperature is 650-700℃, and the time is 1-1.5 h.

5. The high strength cable jacket material of claim 1, wherein, The preparation process of the flame retardant is as follows: (a) The ethanol solution of 5-hydroxy-1-naphthaldehyde is added to the ethanol solution of 1,10-phenanthroline-3,8-diamine, and reacted under inert gas atmosphere and heating condition; after the reaction is completed, the reaction liquid is cooled to room temperature, filtered, and the collected solid is washed and dried to obtain intermediate 1; (b) The intermediate 1 and 9,10-dihydro-9-oxa-10-phospha-phenanthrene-10-oxide are added to ethanol, and refluxed under inert gas atmosphere; after the reaction is completed, the product is purified to obtain the flame retardant.

6. The high strength cable jacket material of claim 5, wherein, 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℃, and the reaction time is 4-6 h.

7. The high strength cable jacket material of claim 5, wherein, In step (b), the molar ratio of intermediate 1 to 9,10-dihydro-9-oxa-10-phospha-phenanthrene-10-oxide is 1:(2-2.5); and the reflux reaction time is 2-3 d.

8. The high strength cable jacket material of claim 1, wherein, The polyurethane is a polyether type thermoplastic polyurethane with a hardness of 75-85A; the dispersant is RL16; the antioxidant is at least one of antioxidant 1010, antioxidant 1024 and antioxidant 168.

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

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

Images