Temperature-resistant and wear-resistant three-layer insulated wire and preparation method thereof

Abstract

The application discloses a kind of temperature-resistant wear-resistant three-layer insulated wire and preparation method thereof, it is related to cable technical field.The preparation method of the application is: the surface of conductor material is extruded and packed inner layer material to form inner insulation layer, then the surface of inner insulation layer is extruded and packed modified silicone rubber to form middle layer, then the surface of middle layer is extruded and packed outer layer material to form outer insulation layer, and high-temperature-resistant flame-retardant cable material is obtained after curing.In which, inner layer material is made of low-density polyethylene, antioxidant 1010, insulation particle, voltage stabilizer and the like;Modified silicone rubber is made of silicone rubber, boron nitride compound, modified magnesium oxide and the like;Outer layer material is made of inner layer material, boron nitride compound.The introduction of insulation particle, voltage stabilizer, boron nitride compound and the like components effectively improves the high-voltage resistance, aging resistance, wear resistance and temperature resistance of crosslinked polyethylene insulated power cable wire.Therefore, the application has wide application prospect.

Description

Technical Field

[0001] This invention relates to the field of cable technology, specifically to a temperature-resistant and wear-resistant triple-insulated wire and its preparation method. Background Technology

[0002] Cross-linked polyethylene (XLPE) is a modified polymer material that forms a three-dimensional network structure through a cross-linking reaction. It possesses excellent heat resistance, creep resistance, impact resistance, and electrical insulation properties, and is widely used for insulation in high-voltage power cables. With the continuous development of ultra-high voltage / extra-high voltage transmission technology, the voltage levels of power cables are constantly increasing, and the requirements for the electrical performance of insulation materials are becoming increasingly stringent, which ordinary XLPE materials can hardly meet.

[0003] However, cross-linked polyethylene (XLPE) cable insulation materials still suffer from poor insulation under high voltage fields, susceptibility to aging under high temperature and pressure, and relatively poor wear resistance and high temperature resistance in practical applications, which limits their use. Therefore, the high voltage resistance, aging resistance, wear resistance, and temperature resistance of existing XLPE cable insulation materials still need further improvement. Summary of the Invention

[0004] The purpose of this invention is to provide a temperature- and wear-resistant triple-insulated wire and its preparation method, thereby solving the following technical problems:

[0005] Existing cross-linked polyethylene insulated power cables still have problems with poor high voltage resistance, aging resistance, abrasion resistance, and temperature resistance.

[0006] The objective of this invention can be achieved through the following technical solutions:

[0007] A method for preparing a temperature-resistant and wear-resistant triple-insulated wire includes the following steps:

[0008] An inner insulation layer with a thickness of 2-3 mm is formed by extruding an inner layer material onto the surface of the conductor material. Then, modified silicone rubber is extruded onto the surface of the inner insulation layer to form an intermediate layer with a thickness of 1-2 mm. Finally, an outer insulation layer with a thickness of 0.8-1 mm is extruded onto the surface of the intermediate layer and cured at 150-170℃ and 18MPa for 3-4 hours to obtain a high-temperature resistant flame-retardant cable material.

[0009] The inner layer material is made of low-density polyethylene, antioxidant 1010, insulating particles, voltage stabilizer, and dicumyl peroxide.

[0010] The modified silicone rubber is made of silicone rubber, boron nitride compound, modified magnesium oxide, and dicumyl peroxide;

[0011] The outer layer material is made of the inner layer material and a boron nitride composite.

[0012] The insulating particles are composed of zirconium phosphate nanosheets modified with a silane coupling agent and MXene coated with silica.

[0013] The voltage stabilizer is oxaloylbis(p-phenylene)bismaleimide;

[0014] The boron nitride composite is formed by combining hexagonal boron nitride nanotubes with a borazine-ammoniaborane prepolymer after hydrogen peroxide surface treatment;

[0015] The modified magnesium oxide is nano-magnesium oxide that has been pretreated with a silane coupling agent and then modified with methane plasma.

[0016] Preferably, the preparation method of the inner layer material is as follows:

[0017] Low-density polyethylene is mixed at 130-140℃ for 1-2 minutes, then antioxidant 1010 is added and mixed for 2-3 minutes, then insulating particles are added and mixed for 2-3 minutes, then voltage stabilizer is added and ultrasonically assisted stirring is performed for 8-10 minutes, then mixed at 105-110℃ for 3-5 minutes, and finally dicumyl peroxide is added and mixed for 1-2 minutes to obtain the inner layer material.

[0018] The mass ratio of the low-density polyethylene, antioxidant 1010, insulating granules, voltage stabilizer, and dicumyl peroxide is 400-500:1.2-1.5:0.5-1:1.2-1.5:5.2-6.5.

[0019] Preferably, the modified silicone rubber is prepared by the following method:

[0020] After degassing the silicone rubber under vacuum, add boron nitride composite and stir for 10-20 min. Then add modified magnesium oxide and stir for 20-30 min. Finally, add dicumyl peroxide and stir at 45-55℃ for 30-50 min. After vacuuming, the modified silicone rubber is obtained.

[0021] The mass ratio of the silicone rubber, boron nitride compound, modified magnesium oxide, and dicumyl peroxide is 100-120:0.8-1.2:5-6:1-1.2.

[0022] Preferably, the outer layer material is prepared by the following method:

[0023] Add boron nitride complex to the inner layer material and mix at 105-110℃ for 3-5 minutes to obtain the outer layer material;

[0024] The mass ratio of the inner layer material to the boron nitride composite is 200-240:1-3.

[0025] Preferably, the method for preparing the insulating particles is as follows:

[0026] A1: Add titanium aluminum carbide powder to hydrofluoric acid aqueous solution and stir for 20-25h. Centrifuge and wash until the pH is 6.5-7.5 after adding deionized water. Then add tetraethyl orthosilicate and ammonia water and stir at 55-60℃ for 2-2.5h. Then add to dimethyl sulfoxide aqueous solution and sonicate for 1-2h to obtain MXene colloid.

[0027] A2: Add zirconium oxychloride octahydrate and concentrated phosphoric acid to deionized water and react at 140-150℃ for 45-50h. After centrifugation and washing until pH 6-7, add the precipitate to tetrabutylammonium hydroxide aqueous solution, seal and stir at 55-60℃ for 20-25h. Then add deionized water and sonicate for 30-50min. After centrifugation, vacuum dry the supernatant and grind it to obtain zirconium phosphate nanosheets.

[0028] A3: Add zirconium phosphate nanosheets to deionized water and sonicate for 20-40 min. Adjust the pH to 3-5, add silane coupling agent KH550 and sonicate for 20-40 min. After centrifugation and washing of the precipitate, add it to deionized water and sonicate for 20-30 min. Then add MXene colloid and stir well. Adjust the pH to 5 and stir at 55-60℃ for 4-6 h. After centrifugation and drying, insulating particles are obtained.

[0029] Preferably, the mass ratio of the hydrofluoric acid aqueous solution, titanium aluminum carbide powder, deionized water, tetraethyl orthosilicate, ammonia, and dimethyl sulfoxide aqueous solution in A1 is 10-12:1-1.2:55-65:10-12:5-6:530-636;

[0030] The hydrofluoric acid aqueous solution described in A1 has a mass fraction of 40%;

[0031] The mass fraction of ammonia in A1 is 25%;

[0032] The mass fraction of the dimethyl sulfoxide aqueous solution in A1 is 80%-85%;

[0033] The mass ratio of the deionized water, zirconium oxychloride octahydrate, concentrated phosphoric acid, and tetrabutylammonium hydroxide aqueous solution in A2 is 200-240:10-12:15-20:100-120;

[0034] The concentrated phosphoric acid in A2 has a mass fraction of 85%;

[0035] The mass fraction of the tetrabutylammonium hydroxide aqueous solution in A2 is 5%;

[0036] The mass ratio of deionized water, zirconium phosphate nanosheets, silane coupling agent KH550, deionized water, and MXene colloid in A3 is 20-24:0.6-0.7:0.02-0.04:1000-1200:300-360.

[0037] Preferably, the boron nitride complex is prepared by the following method:

[0038] B1: Dissolve borazine and ammonia borane in tetrahydrofuran and reflux under nitrogen atmosphere for 5-7 h, then remove the solvent by vacuum distillation to obtain the prepolymer;

[0039] B2: Add hexagonal boron nitride nanotubes to an aqueous hydrogen peroxide solution and sonicate for 2-3 hours. Wash with water until the pH is 6.5-7.5 and then vacuum dry. Disperse the nanotubes in anhydrous ethanol, add the prepolymer and stir with ultrasonic assistance for 1-1.5 hours. After curing and grinding, the boron nitride composite is obtained.

[0040] Preferably, the mass ratio of borazine, aminoborane, and tetrahydrofuran in B1 is 20-24:5-6:100-120;

[0041] The mass ratio of hydrogen peroxide aqueous solution, hexagonal boron nitride nanotubes, anhydrous ethanol, and prepolymer in B2 is 400-500: 8-10: 150-200: 16-20;

[0042] The mass fraction of the hydrogen peroxide aqueous solution described in B2 is 3%-5%.

[0043] Preferably, the modified magnesium oxide is prepared by the following method:

[0044] C1: Add nano-magnesium oxide to anhydrous ethanol and sonicate at 45-50℃ for 20-40 min. Then add silane coupling agent KH560 and sonicate for 20-40 min. After centrifugation, wash the precipitate, dry it, and grind it to obtain pretreated magnesium oxide.

[0045] C2: Pretreated magnesium oxide is subjected to plasma treatment for 20-30 minutes at a pressure of 13-13.5 kPa, a voltage of 10-20 kV, and a frequency of 8-9 kHz under a methane atmosphere to obtain modified magnesium oxide.

[0046] The mass ratio of anhydrous ethanol, nano-magnesium oxide, and silane coupling agent KH560 in C1 is 20-40:8-10:0.1-0.5.

[0047] Preferably, the voltage stabilizer is prepared by the following method:

[0048] D1: Add 4,4'-dichlorobenzoyl to dimethylformamide and stir well to obtain a 4,4'-dichlorobenzoyl solution;

[0049] D2: Add maleimide to dimethylformamide and stir well to obtain a maleimide solution;

[0050] D3: Add cuprous iodide to dimethylformamide and stir well to obtain a cuprous iodide solution;

[0051] D4: Add N,N-dimethylethylenediamine and potassium carbonate to dimethylformamide and stir well. Then add cuprous iodide solution and stir well. Then add 4,4'-dichlorobenzoyl solution while stirring and stir well. Finally, add maleimide solution dropwise while stirring at 98-100℃. Reflux at 98-100℃ under nitrogen atmosphere for 8-9 hours. After cooling and filtration, wash the filtrate with acid, thin wash, and water until the pH is 6.5-7.5. Add anhydrous sodium sulfate, dry, filter, and remove the solvent by rotary evaporation to obtain the voltage stabilizer.

[0052] Preferably, the mass ratio of dimethylformamide to 4,4'-dichlorobenzoyl in D1 is 40-80:14-28;

[0053] The mass ratio of dimethylformamide to maleimide in D2 is 50-100:17-34;

[0054] The mass ratio of dimethylformamide to cuprous iodide in D3 is 25-50:0.5-1;

[0055] The mass ratio of dimethylformamide, N,N-dimethylethylenediamine, potassium carbonate, cuprous iodide solution, 4,4'-dichlorobenzoyl solution, and maleimide solution in D4 is 10-20:0.88-1.76:0.1-0.2:25.5-51:54-108:67-134.

[0056] The beneficial effects of this invention are:

[0057] This invention provides a temperature- and wear-resistant triple-insulated wire and its preparation method. The invention effectively improves the high-voltage resistance, aging resistance, wear resistance and temperature resistance of cross-linked polyethylene insulated power cables through the following method.

[0058] (1) In the modified magnesium oxide of this invention, magnesium oxide itself is resistant to high temperature. After pretreatment with silane coupling agent and modification with methane plasma, its compatibility with the organic matrix is ​​significantly improved. It can effectively hinder the thermal motion of the matrix molecular chains, delay thermal degradation, and thus improve the product's temperature resistance and resistance to thermo-oxidative aging. Nano magnesium oxide has high hardness. After modification, it can reduce the shedding of fillers during friction and reduce the wear aggravation caused by interface defects, thereby enhancing the product's wear resistance. Magnesium oxide is an excellent insulating material. After modification, it can form a continuous insulating network in the matrix, hindering charge migration and improving or maintaining the product's good insulation properties. Magnesium oxide can inhibit the growth of electrical trees, and after modification, it reduces interface voids, reducing the aging induction under voltage, thereby improving the product's high voltage resistance and resistance to electrical aging.

[0059] (2) The hexagonal boron nitride nanotubes in the boron nitride composite of the present invention have extremely high thermal stability and high temperature resistance, while the prepolymer generated by the reaction of borazine and ammonia borane forms a high temperature resistant network after curing. The combination of the two can effectively enhance the thermal stability and improve the temperature resistance of the material. The hexagonal boron nitride nanotubes can improve the hardness and mechanical strength of the material, and the tight interface formed with the prepolymer can reduce particle shedding during the wear process, thereby enhancing wear resistance. The hexagonal boron nitride nanotubes have extremely high surface and volume resistivity and excellent dielectric properties. After being combined, they can be uniformly dispersed in the matrix to form an insulating network, effectively hindering carrier migration, improving the insulation resistance of the material, and reducing dielectric loss; at the same time, the prepolymer itself has good insulation properties, which can synergistically improve the overall insulation of the material. Hexagonal boron nitride nanotubes can reduce local electric field concentration, inhibit electrical tree growth, and improve the overall breakdown field strength of composite materials. Their excellent thermal conductivity helps to quickly dissipate local hot spots, preventing insulation performance degradation or even breakdown due to local overheating. They can also effectively shield the diffusion of aging factors such as oxygen and moisture into the polymer matrix. Nitrogen- and boron-containing prepolymers can inhibit aging degradation under voltage by capturing free radicals and stabilizing molecular chains, thus jointly enhancing the material's resistance to voltage aging. The high thermal stability of the composite itself helps the matrix resist thermo-oxidative aging, and its good heat dissipation capacity can reduce the internal operating temperature of the material, slowing down the oxidative degradation rate at high temperatures. Therefore, the addition of boron nitride composites can significantly delay the aging rate of cable insulation under the influence of heat, oxygen, and humidity, extending the cable's service life.

[0060] (3) The silica layer coating on the surface of MXene, which has excellent high-temperature resistance, further improves the oxidation resistance and thermal stability of the insulating particles of the present invention. At the same time, zirconium phosphate nanosheets also have extremely high thermal stability. The combination of the two can inhibit the thermal decomposition of the matrix, improve the thermal stability range of the material, and enhance the temperature resistance of the product. The insulating particles can form a good interface bond with the matrix. Their addition can improve the hardness and mechanical properties of the material, reduce friction and wear, and enhance wear resistance. The silica insulating layer generated in situ on the surface of MXene can completely encapsulate the conductive MXene and block the conductive path. Zirconium phosphate itself is a highly insulating layered material. After modification with silane coupling agent, it can further modify MXene and inhibit its conductivity. At the same time, the silane coupling agent treatment improves the compatibility with the matrix and reduces interface defects, thereby improving the insulation performance of the product. Insulating particles within the polymer matrix effectively twist and block the propagation of electrical trees, reducing electric field concentration and lowering the probability of partial discharge and breakdown. The interface between the particles and the polymer matrix, as well as the defects within the particles themselves, can act as traps for charge carriers, reducing the probability of them accelerating their impact on molecular chains under high electric fields, leading to breakdown. This improves withstand voltage and, in conjunction with voltage stabilizers, inhibits degradation reactions under voltage, thereby enhancing the product's resistance to electrical aging. Lamellar inorganic particles can form a physical barrier layer, hindering the diffusion and penetration of oxygen, small molecule degradation products, and potential water vapor within the material, significantly slowing down the thermo-oxidative aging rate of the polymer matrix.

[0061] (4) The voltage stabilizer in this invention contains a large number of conjugated aromatic rings and strongly polar groups, which can effectively capture free electrons and holes generated by electric field, heat or radiation in the material and prevent them from forming conductive channels; it can also change the local electric field distribution and reduce the electric field concentration; it can also effectively inhibit the initiation and growth of electrical trees and prevent the insulation layer from being broken down under long-term high voltage; thus, it significantly improves the volume resistivity and surface resistivity of the material, reduces dielectric loss, enhances its resistance to partial discharge and electrical breakdown, as well as short-time power frequency breakdown voltage, lightning impulse breakdown voltage and long-term withstand voltage life. The voltage stabilizer can significantly improve the electrical aging life of the material by inhibiting electrical treeing and partial discharge; it can also improve the overall thermo-oxidative stability of the material, and at the same time reduce the heat and active substances generated by partial discharge, indirectly slowing down the thermal aging process; when used in combination with antioxidant 1010, it can also provide more comprehensive antioxidant protection. The improvement of insulation and the ability to inhibit electrothermal effect can also enable the material to maintain the stability of its electrical properties at higher operating temperatures.

[0062] Therefore, the temperature-resistant and wear-resistant triple-insulated wire prepared by this invention has excellent high-voltage resistance, aging resistance, wear resistance, temperature resistance, and a wider range of application prospects. Detailed Implementation

[0063] 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.

[0064] Unless otherwise specified, the following information pertains to some of the raw materials used in the following embodiments and comparative examples of this invention:

[0065] Silicone rubber (RTV-II type) was purchased from Hebei Zhonglian Huayu Electric Power Technology Co., Ltd.; titanium aluminum carbide powder was purchased from Forsmann Technology (Beijing) Co., Ltd., item number: 2203009; low-density polyethylene was purchased from Sinopec Yanshan Branch, model: LD920.

[0066] Example 1: A method for preparing a temperature-resistant and wear-resistant triple-insulated wire is as follows:

[0067] S1: Add 8g of nano magnesium oxide to 20g of anhydrous ethanol and ultrasonically disperse at 45℃ for 20min. Then add 0.1g of silane coupling agent KH560 and ultrasonically disperse for 20min. Then centrifuge and wash the precipitate twice with anhydrous ethanol. Dry at 75℃ and grind to obtain pretreated magnesium oxide.

[0068] S2: Pretreated magnesium oxide was subjected to plasma treatment for 20 minutes at a pressure of 13 kPa, a voltage of 10 kV, and a frequency of 8 kHz under a methane atmosphere to obtain modified magnesium oxide.

[0069] S3: Dissolve 20g of borazine and 5g of ammonia borane in 100g of tetrahydrofuran and reflux at 63°C under a nitrogen atmosphere for 5h. Then remove the solvent by vacuum distillation at 40°C to obtain the prepolymer.

[0070] S4: Add 8g of hexagonal boron nitride nanotubes to 400g of 3% hydrogen peroxide aqueous solution and sonicate for 2h. Wash with water until pH is 6.5 and then vacuum dry at 75℃. Then disperse in 150g of anhydrous ethanol, add 16g of prepolymer and stir for 1h with ultrasonic assistance. Finally, cure at 120℃ for 1h and grind to obtain boron nitride composite.

[0071] S5: Degas 100g of silicone rubber under vacuum for 20min, then add 0.8g of boron nitride composite and stir for 10min, then add 5g of modified magnesium oxide and stir for 20min, finally add 1g of dicumyl peroxide and stir at 3000r / min at 45℃ for 30min, then vacuum for 20min to obtain modified silicone rubber.

[0072] S6: Add 1g of titanium aluminum carbide powder to 10g of 40% hydrofluoric acid aqueous solution and stir for 20h. Centrifuge and wash until the pH is 6.5 after adding 55g of deionized water. Then add 10g of tetraethyl orthosilicate and 5g of 25% ammonia water and stir at 55℃ for 2h. Then add to 530g of 80% dimethyl sulfoxide aqueous solution and sonicate for 1h to obtain MXene colloid.

[0073] S7: Add 10g of zirconium oxychloride octahydrate and 15g of concentrated phosphoric acid (85% by mass) to 200mL of deionized water and react in an autoclave at 140℃ for 45h. After centrifugation and washing until pH 6, add the precipitate to 100g of tetrabutylammonium hydroxide aqueous solution (5% by mass), seal and stir at 55℃ for 20h. Then add 100g of deionized water and sonicate for 30min. After centrifugation for 4min, vacuum dry the supernatant at 55℃ and grind to obtain zirconium phosphate nanosheets.

[0074] S8: Add 0.6g of zirconium phosphate nanosheets to 20mL of deionized water and sonicate for 20min. Adjust the pH to 3, add 0.02g of silane coupling agent KH550 and sonicate for 20min. Centrifuge and wash the precipitate twice with anhydrous ethanol. Add the precipitate to 1000mL of deionized water and sonicate for 20min. Add 300g of MXene colloid and stir for 10min. Adjust the pH to 5 and stir at 55℃ for 4h. Centrifuge and dry to obtain insulating particles.

[0075] S9: Add 14g of 4,4'-dichlorobenzoyl to 40g of dimethylformamide and stir until homogeneous to obtain a 4,4'-dichlorobenzoyl solution;

[0076] S10: Add 17g of maleimide to 50g of dimethylformamide and stir until homogeneous to obtain a maleimide solution;

[0077] S11: Add 0.5g of cuprous iodide to 25g of dimethylformamide and stir until homogeneous to obtain a cuprous iodide solution;

[0078] S12: Add 0.88g of N,N-dimethylethylenediamine and 0.1g of potassium carbonate to 10g of dimethylformamide and stir until homogeneous. Then add 25.5g of cuprous iodide solution and stir for 10min. Then add 54g of 4,4'-dichlorobenzoyl solution while stirring and stir for 10min. Finally, add 67g of maleimide solution dropwise while stirring at 98℃. Reflux at 98℃ under nitrogen atmosphere for 9h. After natural cooling and filtration, acid wash the filtrate, wash with 1% sodium carbonate aqueous solution for 4min, rinse with deionized water until pH is 6.5, add anhydrous sodium sulfate to dry, filter, and remove solvent by rotary evaporation of the filtrate to obtain voltage stabilizer.

[0079] S13: Mix 400g of low-density polyethylene at 130℃ and 40r / min for 1min, then add 1.2g of antioxidant 1010 and mix for 2min, then add 0.5g of insulating granules and mix for 2min, then add 1.2g of voltage stabilizer and ultrasonically assisted stirring for 8min, then mix at 105℃ for 5min, and finally add 5.2g of dicumyl peroxide and mix for 1min to obtain the inner layer material;

[0080] S14: Add 1g of boron nitride complex to 200g of inner layer material and stir and mix at 105℃ for 5min to obtain outer layer material;

[0081] S15: An inner insulation layer with a thickness of 2mm is formed by extruding an inner layer material onto the surface of the conductor material. Then, modified silicone rubber is extruded onto the surface of the inner insulation layer to form an intermediate layer with a thickness of 1mm. Finally, an outer insulation layer with a thickness of 0.8mm is extruded onto the surface of the intermediate layer and cured at 150℃ and 18MPa for 4 hours to obtain a temperature-resistant and wear-resistant triple-insulated wire.

[0082] Example 2: A method for preparing a temperature-resistant and wear-resistant triple-insulated wire is as follows:

[0083] S1: Add 9g of nano magnesium oxide to 30g of anhydrous ethanol and ultrasonically disperse at 48℃ for 30min. Then add 0.3g of silane coupling agent KH560 and ultrasonically disperse for 30min. Then centrifuge and wash the precipitate three times with anhydrous ethanol. Dry at 78℃ and grind to obtain pretreated magnesium oxide.

[0084] S2: Pretreated magnesium oxide was subjected to plasma treatment for 25 minutes at a pressure of 13.3 kPa, a voltage of 15 kV, and a frequency of 8.5 kHz under a methane atmosphere to obtain modified magnesium oxide.

[0085] S3: Dissolve 22g of borazine and 5.5g of ammoniaborane in 110g of tetrahydrofuran and reflux at 64℃ under a nitrogen atmosphere for 6h. Then remove the solvent by vacuum distillation at 45℃ to obtain the prepolymer.

[0086] S4: Add 9g of hexagonal boron nitride nanotubes to 450g of 4% hydrogen peroxide aqueous solution and sonicate for 2.5h. Wash with water until pH 7, then vacuum dry at 78℃. Disperse in 175g of anhydrous ethanol, then add 18g of prepolymer and stir with ultrasonic assistance for 1.2h. Finally, cure at 130℃ for 1.5h and grind to obtain boron nitride composite.

[0087] S5: Degas 110g of silicone rubber under vacuum for 25min, then add 1g of boron nitride composite and stir for 15min, then add 5.5g of modified magnesium oxide and stir for 25min, finally add 1.1g of dicumyl peroxide and stir at 3500r / min at 50℃ for 40min, then vacuum for 25min to obtain modified silicone rubber.

[0088] S6: Add 1.1g of titanium aluminum carbide powder to 11g of 40% hydrofluoric acid aqueous solution and stir for 23h. After centrifugation and washing until the pH is 7 after adding 60g of deionized water, add 11g of tetraethyl orthosilicate and 5.5g of 25% ammonia water and stir at 58℃ for 2.2h. Then add to 583g of 83% dimethyl sulfoxide aqueous solution and sonicate for 1.5h to obtain MXene colloid.

[0089] S7: Add 11g of zirconium oxychloride octahydrate and 17.5g of concentrated phosphoric acid (85% by mass) to 220mL of deionized water and react in an autoclave at 145℃ for 48h. After centrifugation and washing until pH 6.5, add the precipitate to 110g of tetrabutylammonium hydroxide aqueous solution (5% by mass), seal and stir at 58℃ for 23h. Then add 110g of deionized water and sonicate for 40min. After centrifugation for 5min, vacuum dry the supernatant at 58℃ and grind to obtain zirconium phosphate nanosheets.

[0090] S8: Add 0.65g of zirconium phosphate nanosheets to 22mL of deionized water and sonicate for 30min. Adjust the pH to 4, add 0.03g of silane coupling agent KH550 and sonicate for 30min. Centrifuge and wash the precipitate three times with anhydrous ethanol. Add the precipitate to 1100mL of deionized water and sonicate for 25min. Add 330g of MXene colloid and stir for 20min. Adjust the pH to 5 and stir at 58℃ for 5h. Centrifuge and dry to obtain insulating particles.

[0091] S9: Add 21g of 4,4'-dichlorobenzoyl to 60g of dimethylformamide and stir until homogeneous to obtain a 4,4'-dichlorobenzoyl solution;

[0092] S10: Add 25.5g of maleimide to 75g of dimethylformamide and stir until homogeneous to obtain a maleimide solution;

[0093] S11: Add 0.75g of cuprous iodide to 37.5g of dimethylformamide and stir until homogeneous to obtain a cuprous iodide solution;

[0094] S12: Add 1.32g of N,N-dimethylethylenediamine and 0.15g of potassium carbonate to 15g of dimethylformamide and stir until homogeneous. Then add 28.25g of cuprous iodide solution and stir for 15min. Then add 81g of 4,4'-dichlorobenzoyl solution while stirring and stir for 15min. Finally, add 100.5g of maleimide solution dropwise while stirring at 99℃. Reflux at 99℃ under nitrogen atmosphere for 8.5h. After natural cooling and filtration, acid wash the filtrate, wash with 1% sodium carbonate aqueous solution for 5min, rinse with deionized water until pH is 7, add anhydrous sodium sulfate to dry, filter, and remove the solvent by rotary evaporation of the filtrate to obtain the voltage stabilizer.

[0095] S13: Mix 450g of low-density polyethylene at 135℃ and 50r / min for 1.5min, then add 1.35g of antioxidant 1010 and mix for 2.5min, then add 0.751g of insulating granules and mix for 2.5min, then add 1.35g of voltage stabilizer and ultrasonically assisted stirring for 9min, then mix at 108℃ for 4min, and finally add 5.8g of dicumyl peroxide and mix for 1.5min to obtain the inner layer material;

[0096] S14: Add 2g of boron nitride complex to 220g of inner layer material and stir and mix at 108℃ for 3-5min to obtain outer layer material;

[0097] S15: An inner insulation layer with a thickness of 2.5 mm is formed by extruding an inner layer material on the surface of the conductor material. Then, modified silicone rubber is extruded on the surface of the inner insulation layer to form an intermediate layer with a thickness of 1.5 mm. Finally, an outer insulation layer with a thickness of 0.9 mm is extruded on the surface of the intermediate layer and cured at 160℃ and 18MPa for 3.5 h to obtain a temperature-resistant and wear-resistant triple-insulated wire.

[0098] Example 3: A method for preparing a temperature-resistant and wear-resistant triple-insulated wire is as follows:

[0099] S1: Add 10g of nano magnesium oxide to 40g of anhydrous ethanol and ultrasonically disperse at 50℃ for 40min. Then add 0.5g of silane coupling agent KH560 and ultrasonically disperse for 40min. Then centrifuge and wash the precipitate 4 times with anhydrous ethanol. Dry at 80℃ and grind to obtain pretreated magnesium oxide.

[0100] S2: Pretreated magnesium oxide was subjected to plasma treatment for 30 minutes at a pressure of 13.5 kPa, a voltage of 20 kV, and a frequency of 9 kHz under a methane atmosphere to obtain modified magnesium oxide.

[0101] S3: Dissolve 24g of borazine and 6g of ammoniaborane in 120g of tetrahydrofuran and reflux at 65°C under a nitrogen atmosphere for 7h. Then remove the solvent by vacuum distillation at 50°C to obtain the prepolymer.

[0102] S4: Add 10g of hexagonal boron nitride nanotubes to 500g of 5% hydrogen peroxide aqueous solution and sonicate for 3h. Wash with water until pH 7.5, then vacuum dry at 80℃. Disperse in 200g of anhydrous ethanol, then add 20g of prepolymer and stir for 1.5h with ultrasonic assistance. Finally, cure at 150℃ for 2h and grind to obtain boron nitride composite.

[0103] S5: Degas 120g of silicone rubber under vacuum for 30min, then add 1.2g of boron nitride composite and stir for 20min, then add 6g of modified magnesium oxide and stir for 30min, finally add 1.2g of dicumyl peroxide and stir at 4000r / min at 55℃ for 50min, and then vacuum for 30min to obtain modified silicone rubber.

[0104] S6: Add 1.2g of titanium aluminum carbide powder to 12g of 40% hydrofluoric acid aqueous solution and stir for 25h. After centrifugation and washing until the pH is 7.5 after adding 65g of deionized water, add 12g of tetraethyl orthosilicate and 6g of 25% ammonia water and stir at 60℃ for 2.5h. Then add to 636g of 85% dimethyl sulfoxide aqueous solution and sonicate for 2h to obtain MXene colloid.

[0105] S7: Add 12g zirconium oxychloride octahydrate and 20g concentrated phosphoric acid (85% by mass) to 240mL of deionized water and react in an autoclave at 150℃ for 50h. After centrifugation and washing until pH 7, add the precipitate to 120g tetrabutylammonium hydroxide aqueous solution (5% by mass), seal and stir at 60℃ for 25h. Then add 120g of deionized water and sonicate for 50min. After centrifugation for 6min, vacuum dry the supernatant at 60℃ and grind to obtain zirconium phosphate nanosheets.

[0106] S8: Add 0.7g of zirconium phosphate nanosheets to 24mL of deionized water and sonicate for 40min. Adjust the pH to 5, add 0.04g of silane coupling agent KH550 and sonicate for 40min. Centrifuge and wash the precipitate 4 times with anhydrous ethanol. Add the precipitate to 1200mL of deionized water and sonicate for 30min. Add 360g of MXene colloid and stir for 30min. Adjust the pH to 5 and stir at 60℃ for 4h. Centrifuge and dry to obtain insulating particles.

[0107] S9: Add 28g of 4,4'-dichlorobenzoyl to 80g of dimethylformamide and stir until homogeneous to obtain a 4,4'-dichlorobenzoyl solution;

[0108] S10: Add 34g of maleimide to 100g of dimethylformamide and stir until homogeneous to obtain a maleimide solution;

[0109] S11: Add 1g of cuprous iodide to 50g of dimethylformamide and stir until homogeneous to obtain a cuprous iodide solution;

[0110] S12: Add 1.76g of N,N-dimethylethylenediamine and 0.2g of potassium carbonate to 20g of dimethylformamide and stir until homogeneous. Then add 51g of cuprous iodide solution and stir for 20min. Then add 108g of 4,4'-dichlorobenzoyl solution while stirring and stir for 20min. Finally, add 134g of maleimide solution dropwise while stirring at 100℃. Reflux at 100℃ under nitrogen atmosphere for 9h. After natural cooling and filtration, acid wash the filtrate, wash with 1% sodium carbonate aqueous solution for 6min, rinse with deionized water until pH 7.5, add anhydrous sodium sulfate to dry, filter, and remove the solvent by rotary evaporation to obtain the voltage stabilizer.

[0111] S13: Mix 500g of low-density polyethylene at 140℃ and 60r / min for 2min, then add 1.5g of antioxidant 1010 and mix for 3min, then add 1g of insulating granules and mix for 3min, then add 1.5g of voltage stabilizer and ultrasonically assisted stirring for 10min, then mix at 110℃ for 3min, and finally add 6.5g of dicumyl peroxide and mix for 2min to obtain the inner layer material;

[0112] S14: Add 3g of boron nitride compound to 240g of inner layer material and stir and mix at 110℃ for 3min to obtain outer layer material;

[0113] S15: An inner insulation layer with a thickness of 3mm is formed by extruding an inner layer material onto the surface of the conductor material. Then, modified silicone rubber is extruded onto the surface of the inner insulation layer to form an intermediate layer with a thickness of 2mm. Finally, an outer insulation layer with a thickness of 1mm is extruded onto the surface of the intermediate layer and cured at 170℃ and 18MPa for 3 hours to obtain a temperature-resistant and wear-resistant triple-insulated wire.

[0114] Comparative Example 1:

[0115] Compared with Example 1, this comparative example only replaces the "modified magnesium oxide" added in the preparation process of S5 with "pretreated magnesium oxide". All other steps and parameters are the same, and will not be repeated in this comparative example. Finally, a temperature-resistant and wear-resistant triple-insulated wire is obtained.

[0116] Comparative Example 2:

[0117] Compared with Example 1, this comparative example only did not add "modified magnesium oxide" in the preparation process of S5. All other steps and parameters were the same, and will not be repeated here. The final result was a temperature-resistant and wear-resistant triple-insulated wire.

[0118] Comparative Example 3:

[0119] Compared with Example 1, this comparative example only replaces the "boron nitride complex" added in the preparation process of S5 with "hexagonal boron nitride nanotubes". All other steps and parameters are the same, and will not be repeated in this comparative example. Finally, a temperature-resistant and wear-resistant triple-insulated wire is obtained.

[0120] Comparative Example 4:

[0121] Compared with Example 1, this comparative example only omits the step of "adding 10g of tetraethyl orthosilicate and 5g of ammonia with a mass fraction of 25% and stirring at 55°C for 2 hours" in the preparation process of S6. All other steps and parameters are the same, and will not be repeated in this comparative example. The final result is a temperature-resistant and wear-resistant triple-insulated wire.

[0122] Comparative Example 5:

[0123] Compared with Example 1, this comparative example only did not add "MXene colloid" in the preparation process of S8. All other steps and parameters were the same, and will not be repeated here. The final result was a temperature-resistant and wear-resistant triple-insulated wire.

[0124] Comparative Example 6:

[0125] Compared with Example 1, this comparative example only omits the addition of "insulating particles" during the preparation process of S13. All other steps and parameters are the same, and will not be repeated here. The final result is a temperature-resistant and wear-resistant triple-insulated wire.

[0126] Comparative Example 7:

[0127] Compared with Example 1, this comparative example only omits the addition of a "voltage stabilizer" during the preparation process of S13. All other steps and parameters are the same, and will not be repeated here. The final result is a temperature-resistant and wear-resistant triple-insulated wire.

[0128] Comparative Example 8:

[0129] Compared with Example 1, this comparative example only did not add "boron nitride complex" in the preparation process of S14. All other steps and parameters were the same, and will not be repeated here. The final result was a temperature-resistant and wear-resistant triple-insulated wire.

[0130] Performance testing:

[0131] Abrasion resistance testing:

[0132] Referring to GB / T 1689-2014 "Determination of Abrasion Resistance of Vulcanized Rubber (using Akron Abrasion Tester)", the abrasion amount (cm) of the temperature-resistant and abrasion-resistant triple-insulated wires prepared in Examples 1-3 and Comparative Examples 1-8 of this invention after rubbing for 1.61 km under a constant load of 26.5 N with a 100-mesh silicon carbide grinding wheel was determined. 3 The test results are shown in Table 1.

[0133] Measurement of volume resistivity:

[0134] Referring to GB / T 1410-2006 "Test Methods for Volume Resistivity and Surface Resistivity of Solid Insulating Materials", the volume resistivity (Ω·m) of the three-layer insulation materials of the temperature-resistant and wear-resistant three-layer insulation wires prepared in Examples 1-3 and Comparative Examples 1-8 of this invention was determined at 25℃ and 150℃. The test results are shown in Table 1.

[0135] Determination of heat distortion temperature:

[0136] Referring to GB / T 1634.2-2004 "Determination of Deformation Temperature of Plastics under Load - Part 2: Plastics, Hard Rubber and Long Fiber Reinforced Composites", the heat distortion temperature (°C) of the three-layer insulation material of the heat-resistant and wear-resistant three-layer insulation wires prepared in Examples 1-3 and Comparative Examples 1-8 of this invention was determined under a load of 1 MPa. The test results are shown in Table 1.

[0137] Determination of aging resistance:

[0138] Referring to GB / T 2951.12-2008 "General Test Methods for Insulation and Sheath Materials of Cables and Optical Wires - Part 12: General Test Methods - Thermal Aging Test Method", the tensile strength retention rate (%) of the three-layer insulation materials of the temperature-resistant and wear-resistant three-layer insulation wires prepared in Examples 1-3 and Comparative Examples 1-8 of this invention after aging at 150℃ for 168h was determined. The test results are shown in Table 1.

[0139] Measurement of electrical strength:

[0140] Referring to GB / T 1408.1-2016 "Electrical Strength Test Methods for Insulating Materials Part 1: Tests at Power Frequency", a step-by-step voltage increase test with a step-up rate of 1 kV / s was conducted to determine the DC breakdown voltage of the three-layer insulation material of the temperature-resistant and wear-resistant three-layer insulation wires prepared in Examples 1-3 and Comparative Examples 1-8 of this invention at 20°C, and the corresponding electrical strength (kV·mm) was calculated. -1 The test results are shown in Table 1.

[0141] Table 1: Performance test results of Examples 1-3 and Comparative Examples 1-8

[0142]

[0143] Data Analysis:

[0144] As can be seen from Table 1, the temperature-resistant and wear-resistant triple-insulated wire prepared according to the embodiments of the present invention has excellent wear resistance, insulation, temperature resistance, aging resistance and high voltage resistance.

[0145] The foregoing has provided a detailed description of one embodiment of the present invention, but this description is merely a preferred embodiment and should not be construed as limiting the scope of the invention. All equivalent variations and modifications made within the scope of the claims of this invention should still fall within the patent coverage of this invention.

Claims

1. A process for the preparation of a temperature and abrasion resistant three-layer insulated wire, characterized in that, The method comprises the following steps: The inner insulation layer is formed by extruding the inner layer material on the surface of the conductor material, then the intermediate layer is formed by extruding the modified silicone rubber on the surface of the inner insulation layer, and then the outer insulation layer is formed by extruding the outer layer material on the surface of the intermediate layer, and the high-temperature-resistant and flame-retardant cable material is obtained after curing; The inner layer material is made of low-density polyethylene, antioxidant 1010, insulation particles, voltage stabilizer and dicumyl peroxide; The modified silicone rubber is made of silicone rubber, boron nitride compound, modified magnesium oxide and dicumyl peroxide; The outer layer material is made of the inner layer material and boron nitride compound; The insulation particles are made of zirconium phosphate nanosheets modified by silane coupling agent and then compounded with MXene coated with silicon dioxide; The voltage stabilizer is oxalyl bis (p-phenylene) bismaleimide; The boron nitride compound is formed by combining hexagonal boron nitride nanotubes treated by hydrogen peroxide with borazine-ammonia borane prepolymer; The modified magnesium oxide is nano-magnesium oxide pretreated by silane coupling agent and then modified by methane plasma.

2. The method for preparing a temperature-resistant and wear-resistant triple-insulated wire according to claim 1, characterized in that, The preparation method of the inner layer material is as follows: The low-density polyethylene is mixed at 130-140 DEG C for 1-2 min, then the antioxidant 1010 is added and mixed for 2-3 min, then the insulation particles are added and mixed for 2-3 min, then the voltage stabilizer is added and ultrasonic-assisted stirring is performed for 8-10 min, then mixing is performed at 105-110 DEG C for 3-5 min, and finally the dicumyl peroxide is added and mixed for 1-2 min to obtain the inner layer material; The mass ratio of the low-density polyethylene, antioxidant 1010, insulation particles, voltage stabilizer and dicumyl peroxide is 400-500:1.2-1.5:0.5-1:1.2-1.5:5.2-6.

5.

3. The method for preparing a temperature-resistant and wear-resistant triple-insulated wire according to claim 1, characterized in that, The preparation method of the modified silicone rubber is as follows: The silicone rubber is degassed under vacuum, then the boron nitride compound is added and stirred, then the modified magnesium oxide is added and stirred, finally the dicumyl peroxide is added and stirred at 45-55 DEG C for 30-50 min, and then the modified silicone rubber is obtained after vacuum extraction; The mass ratio of the silicone rubber, boron nitride compound, modified magnesium oxide and dicumyl peroxide is 100-120:0.8-1.2:5-6:1-1.

2.

4. The method for preparing a temperature-resistant and wear-resistant triple-insulated wire according to claim 1, characterized in that, The preparation method of the outer layer material is as follows: The boron nitride compound is added to the inner layer material and stirred and mixed at 105-110 DEG C for 3-5 min to obtain the outer layer material; The mass ratio of the inner layer material and boron nitride compound is 200-240:1-3.

5. The method for preparing a temperature-resistant and wear-resistant triple-insulated wire according to claim 1, characterized in that, The preparation method of the insulation particles is as follows: A1: titanium aluminum carbide powder is added to an aqueous hydrofluoric acid solution and stirred for 20-25 h, centrifugal washing is performed until the pH of the deionized water is 6.5-7.5, then tetraethyl orthosilicate and ammonia water are added and stirred at 55-60 DEG C for 2-2.5 h, then the mixture is added to an aqueous dimethyl sulfoxide solution and ultrasonic treatment is performed for 1-2 h to obtain a MXene colloid; A2: adding zirconium oxychloride octahydrate, concentrated phosphoric acid into deionized water and reacting at 140-150℃ for 45-50h, after centrifugal washing until the pH of the precipitate is 6-7, adding the precipitate into the aqueous solution of tetrabutylammonium hydroxide, sealing and stirring at 55-60℃ for 20-25h, then adding deionized water and ultrasonic for 30-50min, after centrifugal separation, vacuum drying the supernatant, grinding to obtain zirconium phosphate nanosheets; A3: adding zirconium phosphate nanosheets into deionized water and ultrasonic for 20-40min, adding silane coupling agent KH550 after adjusting the pH to 3-5 and ultrasonic for 20-40min, after centrifugal separation and washing the precipitate, adding into deionized water, ultrasonic for 20-30min, then adding MXene colloid and stirring, adjusting the pH to 5 and stirring at 55-60℃ for 4-6h, after centrifugal separation and drying, obtaining insulating particles.

6. The method for preparing a temperature-resistant and wear-resistant triple-insulated wire according to claim 5, characterized in that, The mass ratio of the aqueous hydrofluoric acid, titanium aluminum carbide powder, deionized water, tetraethyl orthosilicate, ammonia water, aqueous dimethyl sulfoxide solution in A1 is 10-12:1-1.2:55-65:10-12:5-6:530-636; The mass fraction of the aqueous hydrofluoric acid in A1 is 40%; The mass fraction of the ammonia water in A1 is 25%; The mass fraction of the aqueous dimethyl sulfoxide solution in A1 is 80%-85%; The mass ratio of the deionized water, zirconium oxychloride octahydrate, concentrated phosphoric acid, aqueous tetrabutylammonium hydroxide solution in A2 is 200-240:10-12:15-20:100-120; The mass fraction of the concentrated phosphoric acid in A2 is 85%; The mass fraction of the aqueous tetrabutylammonium hydroxide solution in A2 is 5%; The mass ratio of the deionized water, zirconium phosphate nanosheets, silane coupling agent KH550, deionized water, MXene colloid in A3 is 20-24:0.6-0.7:0.02-0.04:1000-1200:300-360.

7. The method for preparing a temperature-resistant and wear-resistant triple-insulated wire according to claim 1, characterized in that, The preparation method of the boron nitride composite is as follows: B1: dissolving borazine and ammonia borane in tetrahydrofuran and refluxing under nitrogen atmosphere for 5-7h, then removing the solvent by distillation under reduced pressure to obtain a prepolymer; B2: adding hexagonal boron nitride nanotubes into an aqueous hydrogen peroxide solution and ultrasonic for 2-3h, after washing with water until the pH is 6.5-7.5, vacuum drying, then dispersing in anhydrous ethanol, then adding the prepolymer and stirring under ultrasonic assistance for 1-1.5h, solidifying and grinding to obtain a boron nitride composite.

8. The method for preparing a temperature-resistant and wear-resistant triple-insulated wire according to claim 7, characterized in that, The mass ratio of the borazine, ammonia borane, tetrahydrofuran in B1 is 20-24:5-6:100-120; The mass ratio of the aqueous hydrogen peroxide solution, hexagonal boron nitride nanotubes, anhydrous ethanol, prepolymer in B2 is 400-500:8-10:150-200:16-20; The mass fraction of the aqueous hydrogen peroxide solution in B2 is 3%-5%.

9. The method for preparing a temperature-resistant and wear-resistant triple-insulated wire according to claim 1, characterized in that, The preparation method of the modified magnesium oxide is as follows: C1: adding nano-magnesium oxide into anhydrous ethanol and ultrasonicating for 20-40 min at 45-50 DEG C, then adding silane coupling agent KH560 and ultrasonicating for 20-40 min, centrifuging and washing the precipitate, and drying, grinding to obtain pretreated magnesium oxide; C2: plasma treating the pretreated magnesium oxide under methane gas atmosphere to obtain modified magnesium oxide; The mass ratio of the anhydrous ethanol, nano-magnesium oxide and silane coupling agent KH560 in C1 is 20-40:8-10:0.1-0.

5.

10. A temperature and abrasion resistant three-layer insulated wire, characterized by, The preparation method according to any one of claims 1-9.

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