High-toughness anti-torsion cable for wind power generation

Abstract

The invention discloses a high-toughness anti-torsion cable for wind power generation. The cable sequentially comprises a conductor, an isolating layer, an insulating layer and a protective layer from inside to outside. The protective layer comprises the following components in parts by weight: 100-120 parts of modified polyurethane, 10-12 parts of composite inorganic filler, 2-3 parts of an antioxidant, 1-2 parts of a plasticizer and 1-2 parts of an anti-aging agent. The preparation method has the beneficial effects that a modified monomer containing a special functional group is designed and synthesized and is introduced into a polyurethane system to form a reinforced network, so that the mechanical strength, torsion resistance and heat resistance of the material are remarkably improved; meanwhile, kaolinite is subjected to surface functional modification, so that kaolinite becomes an efficient carrier of hydroxylated carbon nanotubes, and the performance of the composite material is further optimized by inhibiting agglomeration, enhancing interface bonding and constructing a multi-scale collaborative network.

Description

Technical Field

[0001] The present invention belongs to the technical field of cables, and in particular relates to a high-toughness torsion-resistant cable for wind power generation. Background Art

[0002] With the rapid development of wind power technology, the scale and operating environment requirements of wind power equipment are constantly increasing, posing higher challenges to the performance of cables used in wind power generation. Traditional wind power cables have many defects in practical applications. First, the mechanical properties of existing cables are insufficient. Especially under high torsional stress and complex mechanical load conditions, they are prone to breakage or deformation, affecting the stable operation of wind power generation systems. Secondly, the heat resistance of traditional cables is limited. When working in a high temperature environment, the protective layer is prone to aging, resulting in cable performance degradation or even failure. In addition, the torsional resistance of existing cables is poor and cannot effectively withstand the frequent torsional stress of wind power equipment during operation. Especially in large-capacity, long-distance wind power generation scenarios, the torsional life of the cable becomes a key factor limiting system reliability.

[0003] Therefore, in order to solve the above problems, the present invention prepares a high-toughness torsion-resistant cable for wind power generation. Summary of the Invention

[0004] The purpose of the present invention is to overcome the defects of the prior art and provide a high-toughness torsion-resistant cable for wind power generation.

[0005] The purpose of the present invention can be achieved through the following technical solutions:

[0006] A high-toughness, torsion-resistant cable for wind power generation comprises, from the inside out, a conductor, an isolation layer, an insulating layer, and a protective layer; the protective layer comprises the following components, by weight: 100-120 parts of modified polyurethane, 10-12 parts of composite inorganic filler, 2-3 parts of antioxidant, 1-2 parts of plasticizer, and 1-2 parts of antioxidant.

[0007] More optimally, the preparation process of the modified polyurethane is:

[0008] Step 1: Mix polytetrahydrofuran, modified monomer, 1,6-hexamethylene diisocyanate, and dibutyltin dilaurate, raise the temperature to 90-100°C under a protective atmosphere, react for 2-3 hours, and cool to room temperature to obtain a prepolymer;

[0009] Step 2: Mix the prepolymer, tetrafluorobutanediol, and dibutyltin dilaurate, heat to 80-85°C and react for 1-2 hours, cool to 50-60°C, add 1,4-butanediol and dimethylthiotoluene diamine to extend the chain for 20-30 minutes, cool to 40°C, neutralize, filter and wash to obtain modified polyurethane.

[0010] More optimally, the prepolymer comprises the following components: by weight, 20-22 parts of polytetrahydrofuran, 10-15 parts of 1,6-hexamethylene diisocyanate, 8-10 parts of dibutyltin dilaurate, and 12-14 parts of modified monomers; the modified polyurethane raw material comprises the following components: by weight, 12-15 parts of prepolymer, 8-10 parts of tetrafluorobutanediol, 15-20 parts of dibutyltin dilaurate, 4-7 parts of 1,4-butanediol, and 2-5 parts of dimethylthiotoluenediamine.

[0011] More optimally, the preparation process of the modified monomer is:

[0012] S1: Tetrahydrofuran, magnesium, and iodine are mixed and stirred at 55-60°C for 1-2 hours, followed by the slow addition of 4-bromobiphenyl and the mixture is refluxed and stirred for 1-2 hours. After cooling, the resulting mixture is mixed with trichlorocyanuric acid and tetrahydrofuran, and the temperature is raised to 40-50°C. The reaction is continued for 1-2 hours, and the solvent is evaporated under reduced pressure. The mixture is extracted, dried, and purified to obtain biphenyltriazine.

[0013] S2: Biphenyltriazine, acetone, 3-allyl-2-hydroxybenzaldehyde, and sodium hydroxide were mixed, the temperature was raised to 50-60°C, the reaction was continued for 3-4 hours, and after post-treatment, the mixture was transferred to toluene, 4-(bromomethyl)aniline was added, the temperature was raised to 60-80°C, the reaction was continued for 3-4 hours, and the mixture was naturally cooled and filtered, washed, and dried; the mixture was transferred to a round-bottom flask, anhydrous ethanol and sodium borohydride were added, and magnetic stirring was performed at room temperature until no bubbles overflowed. The reaction was continued for 1-2 hours, the solvent was distilled off under reduced pressure, water was added, the mixture was filtered, and dried to obtain intermediate A;

[0014] S3: Mix intermediate A, triphenylphosphine and toluene, increase the temperature to 50-60°C, and stir to react for 6-7 hours. After the reaction is completed, remove the solvent by distillation under reduced pressure. After purification, transfer to acetone. Under a protective atmosphere, add 1-thioglycerol and azobisisobutyronitrile solution, increase the temperature to 70-80°C, react for 3-4 hours, cool to room temperature, filter, wash, and dry to obtain a modified monomer.

[0015] In the scheme, tetrahydrofuran is used as a solvent, magnesium and iodine are mixed to form magnesium iodide, and then 4-bromobiphenyl is slowly added to generate 4-biphenyl magnesium bromide (Grignard reagent). Trichlorocyanuric acid is used as an electrophilic reagent to undergo a nucleophilic addition reaction with the Grignard reagent to ultimately generate biphenyltriazine. The reaction process is shown below:

[0016]

[0017] In the scheme, the phenolic hydroxyl group of 3-allyl-2-hydroxybenzaldehyde generates a more nucleophilic oxygen anion under alkaline conditions, which then undergoes a nucleophilic attack on the remaining chlorine atom in biphenyltriazine. The reaction process is shown below:

[0018]

[0019] Afterwards, the amino group of 4-(bromomethyl)aniline acts as a nucleophile to attack the carbonyl carbon of the aldehyde group it contains, forming an imine intermediate, which is then reduced to a secondary amine by sodium borohydride. The reaction process is as follows:

[0020]

[0021] In the scheme, intermediate A reacts with triphenylphosphine in toluene to generate a phosphonium salt. The double bond contained in the phosphonium salt undergoes a click reaction with 1-thioglycerol in the presence of azobisisobutyronitrile to obtain a modified monomer containing a diol structure, the structural formula of which is shown below:

[0022]

[0023] More optimally, the biphenyltriazine raw material includes the following components: by weight, 200-280 parts of tetrahydrofuran, 10-12 parts of magnesium, 2-3 parts of iodine, 25-28 parts of 4-bromobiphenyl, and 10-12 parts of trichlorocyanuric acid.

[0024] More optimally, the intermediate A raw material includes the following components: by weight, 12-14 parts of biphenyltriazine, acetone, 5-8 parts of 3-allyl-2-hydroxybenzaldehyde, 0.5-0.8 parts of sodium hydroxide, 80-100 parts of toluene, 3-4 parts of 4-(bromomethyl)aniline, 50-60 parts of anhydrous ethanol, 1-2 parts of sodium borohydride, and 80-100 parts of water.

[0025] More optimally, the modified monomer comprises the following components: by weight, 8-10 parts of intermediate A, 2-4 parts of triphenylphosphine, 80-100 parts of toluene, 60-80 parts of acetone, 1-2 parts of 1-thioglycerol, and 0.5-0.8 parts of azobisisobutyronitrile solution.

[0026] More optimally, the composite inorganic filler comprises modified kaolinite and hydroxylated carbon nanotubes in a mass ratio of 1:(5-6).

[0027] More optimally, the preparation process of the modified kaolinite is as follows: under a nitrogen atmosphere, kaolinite is dispersed in N,N-dimethylformamide, a prepolymer is added, and the mixture is stirred at 60-65° C. for 5-6 hours, cooled, filtered, and dried to obtain the modified kaolinite.

[0028] More optimally, the modified kaolinite comprises the following components: by weight, 15-18 parts of kaolinite, 60-80 parts of N,N-dimethylformamide, and 3-5 parts of prepolymer.

[0029] Beneficial effects of the present invention:

[0030] This invention designs and synthesizes modified monomers containing special functional groups and introduces them into the polyurethane system to form a reinforced network, significantly improving the mechanical strength, torsional resistance, and heat resistance of the material. At the same time, the surface of kaolinite is functionalized to make it an efficient carrier for hydroxylated carbon nanotubes. By inhibiting agglomeration, enhancing interfacial bonding, and building a multi-scale collaborative network, the performance of the composite material is further optimized. The details are as follows:

[0031] The first approach involves introducing aromatic side chains into the polyurethane segments, leveraging the synergistic effects of π-π stacking and hydrogen bonding to enhance the mechanical properties of the material. The π-π stacking between the aromatic side chains creates dynamic crosslinks, while hydrogen bonds act as sacrificial bonds that break and reform under external forces, dissipating energy and improving the overall material's torsional resistance and heat resistance.

[0032] Second: In this scheme, the surface of kaolinite is chemically modified using prepolymer chain segments. Since the phosphonium salt contained in the prepolymer has ionic properties, it can undergo non-covalent ion-π interactions with the π electron cloud on the surface of the carbon nanotubes. This interaction can effectively inhibit the aggregation of the carbon nanotubes and make them more evenly dispersed in the polymer matrix. At the same time, the modified kaolinite contains chain segments similar to polyurethane, which effectively improves the compatibility of the inorganic filler in the matrix, thereby further improving the relevant performance of the material. DETAILED DESCRIPTION

[0033] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0034] Example 1: A high-toughness, torsion-resistant cable for wind power generation, comprising the following steps: adding 100 parts of modified polyurethane, 10 parts of composite inorganic filler, 2 parts of antioxidant, 1 part of plasticizer, and 1 part of antioxidant to an internal mixer, heating to 70°C and stirring, after stirring evenly, raising the temperature to 120°C, and increasing the stirring rate, and continuing to stir until fully swollen to obtain a mixture; then adding the mixture to a twin-screw extruder for extrusion to obtain a protective layer; assembling the conductor, isolation layer, insulation layer, and protective layer to obtain a cable.

[0035] Wherein, the preparation process of modified polyurethane is:

[0036] Step 1: 20 parts of polytetrahydrofuran, 10 parts of 1,6-hexamethylene diisocyanate, 8 parts of dibutyltin dilaurate, and 12 parts of modified monomer were mixed, and the temperature was raised to 90° C. under a protective atmosphere, and the mixture was reacted for 2 hours, and then cooled to room temperature to obtain a prepolymer;

[0037] Step 2: 12 parts of prepolymer, 8 parts of tetrafluorobutanediol, and 15 parts of dibutyltin dilaurate were mixed, heated to 80°C for reaction for 1 hour, cooled to 50°C, 1,4-butanediol and 2 parts of dimethylthiotoluenediamine were added for chain extension for 20 minutes, cooled to 40°C, neutralized, filtered and washed to obtain modified polyurethane;

[0038] Wherein, the preparation process of the modified monomer is:

[0039] S1: 100 parts of tetrahydrofuran, 10 parts of magnesium, and 2 parts of iodine were mixed and stirred at 55°C for 1 hour. Then, 25 parts of 4-bromobiphenyl were slowly added and refluxed with stirring for 1 hour. After cooling, the obtained mixture was mixed with 10 parts of trichlorocyanuric acid and 100 parts of tetrahydrofuran, and the temperature was raised to 40°C. The mixture was reacted for 1 hour, and the solvent was evaporated under reduced pressure. The mixture was extracted, dried, and purified to obtain biphenyltriazine;

[0040] S2: 12 parts of biphenyltriazine, acetone, 5 parts of 3-allyl-2-hydroxybenzaldehyde, and 0.5 parts of sodium hydroxide were mixed, the temperature was raised to 50°C, and the mixture was reacted for 3 hours. After post-treatment, the mixture was transferred to 80 parts of toluene, 3 parts of 4-(bromomethyl)aniline were added, the temperature was raised to 60°C, and the reaction was continued for 3 hours. After natural cooling, the mixture was filtered, washed, and dried. The mixture was transferred to a round-bottom flask, 50 parts of anhydrous ethanol and 1 part of sodium borohydride were added, and the mixture was magnetically stirred at room temperature until no bubbles overflowed. The reaction was continued for 1 hour, the solvent was distilled off under reduced pressure, 80 parts of water were added, the mixture was filtered, and dried to obtain intermediate A.

[0041] S3: 8 parts of intermediate A, 2 parts of triphenylphosphine, and 80 parts of toluene were mixed, the temperature was raised to 50°C, and the mixture was stirred and reacted for 6 hours. After the reaction was completed, the solvent was removed by distillation under reduced pressure. After purification, the mixture was transferred to 60 parts of acetone. Under a protective atmosphere, 1 part of 1-thioglycerol and 0.5 parts of azobisisobutyronitrile solution were added. The temperature was raised to 70°C, the mixture was reacted for 3 hours, and the mixture was cooled to room temperature. The mixture was filtered, washed, and dried to obtain a modified monomer.

[0042] Among them, the composite inorganic filler includes modified kaolinite and hydroxylated carbon nanotubes in a mass ratio of 1:5; the preparation process of the modified kaolinite is: under a nitrogen atmosphere, 15 parts of kaolinite are dispersed in 60 parts of N,N-dimethylformamide, 3 parts of prepolymer are added, and the mixture is stirred at 60°C for 5 hours, cooled, filtered, and dried to obtain the modified kaolinite.

[0043] Example 2: 100 parts of modified polyurethane, 10 parts of composite inorganic filler, 2 parts of antioxidant, 1 part of plasticizer, and 1 part of antioxidant were added to an internal mixer, heated to 70°C and stirred. After stirring evenly, the temperature was raised to 120°C, and the stirring rate was increased. Stirring was continued until fully swollen to obtain a mixture; the mixture was then added to a twin-screw extruder and extruded to obtain a protective layer; the conductor, isolation layer, insulation layer, and protective layer were assembled to obtain a cable;

[0044] The preparation process of the modified polyurethane is:

[0045] Step 1: 22 parts of polytetrahydrofuran, 15 parts of 1,6-hexamethylene diisocyanate, 10 parts of dibutyltin dilaurate, and 14 parts of modified monomer were mixed, and the temperature was raised to 100° C. under a protective atmosphere, and the mixture was reacted for 3 hours, and then cooled to room temperature to obtain a prepolymer;

[0046] Step 2: 15 parts of prepolymer, 10 parts of tetrafluorobutanediol, and 20 parts of dibutyltin dilaurate were mixed, heated to 85°C for reaction for 2 hours, cooled to 60°C, 1,4-butanediol and 5 parts of dimethylthiotoluenediamine were added for chain extension for 30 minutes, cooled to 40°C, neutralized, filtered and washed to obtain modified polyurethane;

[0047] Wherein, the preparation process of the modified monomer is:

[0048] S1: 140 parts of tetrahydrofuran, 12 parts of magnesium, and 3 parts of iodine were mixed and stirred at 60°C for 2 hours. Then, 28 parts of 4-bromobiphenyl were slowly added and the mixture was refluxed and stirred for 2 hours. After cooling, the obtained mixture was mixed with 12 parts of trichlorocyanuric acid and 140 parts of tetrahydrofuran, and the temperature was raised to 50°C. The mixture was reacted for 2 hours, and the solvent was evaporated under reduced pressure. The mixture was extracted, dried, and purified to obtain biphenyltriazine;

[0049] S2: 14 parts of biphenyltriazine, acetone, 8 parts of 3-allyl-2-hydroxybenzaldehyde, and 0.8 parts of sodium hydroxide were mixed, the temperature was raised to 60°C, and the reaction was carried out for 4 hours. After post-treatment, the mixture was transferred to 100 parts of toluene, 4 parts of 4-(bromomethyl)aniline were added, the temperature was raised to 80°C, and the reaction was continued for 4 hours. After natural cooling, the mixture was filtered, washed, and dried. The mixture was transferred to a round-bottom flask, 60 parts of anhydrous ethanol and 2 parts of sodium borohydride were added, and the mixture was magnetically stirred at room temperature until no bubbles overflowed. The reaction was continued for 2 hours, the solvent was distilled off under reduced pressure, 100 parts of water were added, the mixture was filtered, and dried to obtain intermediate A.

[0050] S3: 10 parts of intermediate A, 4 parts of triphenylphosphine, and 100 parts of toluene were mixed, the temperature was raised to 60°C, and the mixture was stirred and reacted for 7 hours. After the reaction, the solvent was removed by distillation under reduced pressure. After purification, the mixture was transferred to 80 parts of acetone. Under a protective atmosphere, 2 parts of 1-thioglycerol and 0.8 parts of azobisisobutyronitrile solution were added. The temperature was raised to 80°C, the mixture was reacted for 4 hours, and the mixture was cooled to room temperature, filtered, washed, and dried to obtain a modified monomer.

[0051] Among them, the composite inorganic filler includes modified kaolinite and hydroxylated carbon nanotubes in a mass ratio of 1:6; the preparation process of the modified kaolinite is: under a nitrogen atmosphere, 18 parts of kaolinite are dispersed in 80 parts of N,N-dimethylformamide, 5 parts of prepolymer are added, and the mixture is stirred at 65°C for 6 hours, cooled, filtered, and dried to obtain the modified kaolinite.

[0052] Example 3: 100 parts of modified polyurethane, 10 parts of composite inorganic filler, 2 parts of antioxidant, 1 part of plasticizer, and 1 part of antioxidant were added to an internal mixer, heated to 70°C and stirred. After stirring evenly, the temperature was raised to 120°C, and the stirring rate was increased. Stirring was continued until fully swollen to obtain a mixture; the mixture was then added to a twin-screw extruder and extruded to obtain a protective layer; the conductor, isolation layer, insulation layer, and protective layer were assembled to obtain a cable;

[0053] The preparation process of the modified polyurethane is:

[0054] Step 1: 21 parts of polytetrahydrofuran, 12.5 parts of 1,6-hexamethylene diisocyanate, 9 parts of dibutyltin dilaurate, and 13 parts of a modified monomer were mixed, and the temperature was raised to 95° C. under a protective atmosphere, and the mixture was reacted for 2.5 hours, and then cooled to room temperature to obtain a prepolymer;

[0055] Step 2: 13.5 parts of prepolymer, 9 parts of tetrafluorobutanediol, and 17.5 parts of dibutyltin dilaurate were mixed, heated to 82.5°C for reaction for 1.5 hours, cooled to 55°C, 1,4-butanediol and 3.5 parts of dimethylthiotoluenediamine were added for chain extension for 25 minutes, cooled to 40°C, neutralized, filtered and washed to obtain a modified polyurethane;

[0056] Wherein, the preparation process of the modified monomer is:

[0057] S1: 120 parts of tetrahydrofuran, 11 parts of magnesium, and 2.5 parts of iodine were mixed and stirred at 57.5°C for 1.5 hours, followed by slow addition of 26.5 parts of 4-bromobiphenyl and reflux stirring for 1.5 hours. After cooling, the resulting mixture was mixed with 11 parts of trichlorocyanuric acid and 120 parts of tetrahydrofuran, the temperature was raised to 45°C, the reaction was continued for 1.5 hours, the solvent was evaporated under reduced pressure, extraction was performed, drying was performed, and purification was performed to obtain biphenyltriazine;

[0058] S2: 13 parts of biphenyltriazine, acetone, 6.5 parts of 3-allyl-2-hydroxybenzaldehyde, and 0.65 parts of sodium hydroxide were mixed, the temperature was raised to 55°C, and the reaction was carried out for 3.5 hours. After post-treatment, the mixture was transferred to 90 parts of toluene, 3.5 parts of 4-(bromomethyl)aniline were added, the temperature was raised to 70°C, and the reaction was continued for 3.5 hours. After natural cooling, the mixture was filtered, washed, and dried; the mixture was transferred to a round-bottom flask, 55 parts of anhydrous ethanol and 1.5 parts of sodium borohydride were added, and magnetic stirring was carried out at room temperature until no bubbles overflowed. The reaction was continued for 1.5 hours, the solvent was distilled off under reduced pressure, 90 parts of water were added, the mixture was filtered, and dried to obtain intermediate A;

[0059] S3: 9 parts of intermediate A, 3 parts of triphenylphosphine, and 90 parts of toluene were mixed, the temperature was raised to 55°C, and the mixture was stirred and reacted for 6.5 hours. After the reaction was completed, the solvent was removed by distillation under reduced pressure. After purification, the mixture was transferred to 70 parts of acetone. Under a protective atmosphere, 1.5 parts of 1-thioglycerol and 0.65 parts of azobisisobutyronitrile solution were added. The temperature was raised to 75°C, the mixture was reacted for 3.5 hours, and the mixture was cooled to room temperature. The mixture was filtered, washed, and dried to obtain a modified monomer.

[0060] Among them, the composite inorganic filler includes modified kaolinite and hydroxylated carbon nanotubes in a mass ratio of 1:5.5; the preparation process of the modified kaolinite is: under a nitrogen atmosphere, 16.5 parts of kaolinite are dispersed in 70 parts of N,N-dimethylformamide, 4 parts of prepolymer are added, and the mixture is stirred at 62.5°C for 5.5 hours, cooled, filtered, and dried to obtain the modified kaolinite.

[0061] Comparative Example 1: During the synthesis of the polyurethane in the protective layer, no modifying monomer was added, and the rest was the same as in Example 3, as follows:

[0062] 100 parts of modified polyurethane, 10 parts of composite inorganic filler, 2 parts of antioxidant, 1 part of plasticizer, and 1 part of antioxidant are added to an internal mixer, heated to 70°C and stirred. After stirring evenly, the temperature is raised to 120°C, and the stirring rate is increased. Stirring is continued until fully swollen to obtain a mixture; the mixture is then added to a twin-screw extruder and extruded to obtain a protective layer; the conductor, isolation layer, insulation layer, and protective layer are assembled to obtain a cable;

[0063] The preparation process of the polyurethane is:

[0064] Step 1: 21 parts of polytetrahydrofuran, 12.5 parts of 1,6-hexamethylene diisocyanate, and 6 parts of dibutyltin dilaurate were mixed, and the temperature was raised to 95° C. under a protective atmosphere, and the mixture was reacted for 2.5 hours, and then cooled to room temperature to obtain a prepolymer;

[0065] Step 2: Mix 13.5 parts of prepolymer, 9 parts of tetrafluorobutanediol, and 17.5 parts of dibutyltin dilaurate, heat to 82.5°C and react for 1.5 hours, cool to 55°C, add 1,4-butanediol and 3.5 parts of dimethylthiotoluene diamine to extend the chain for 25 minutes, cool to 40°C, neutralize, filter and wash to obtain polyurethane.

[0066] Among them, the composite inorganic filler includes modified kaolinite and hydroxylated carbon nanotubes in a mass ratio of 1:5.5; the preparation process of the modified kaolinite is: under a nitrogen atmosphere, 16.5 parts of kaolinite are dispersed in 70 parts of N,N-dimethylformamide, 4 parts of prepolymer are added, and the mixture is stirred at 62.5°C for 5.5 hours, cooled, filtered, and dried to obtain the modified kaolinite.

[0067] Comparative Example 2: No kaolinite was added, and the rest was the same as in Example 3, as follows:

[0068] 100 parts of modified polyurethane, 10 parts of composite inorganic filler, 2 parts of antioxidant, 1 part of plasticizer, and 1 part of antioxidant are added to an internal mixer, heated to 70°C and stirred. After stirring evenly, the temperature is raised to 120°C, and the stirring rate is increased. Stirring is continued until fully swollen to obtain a mixture; the mixture is then added to a twin-screw extruder and extruded to obtain a protective layer; the conductor, isolation layer, insulation layer, and protective layer are assembled to obtain a cable;

[0069] The preparation process of the modified polyurethane is:

[0070] Step 1: 21 parts of polytetrahydrofuran, 12.5 parts of 1,6-hexamethylene diisocyanate, 9 parts of dibutyltin dilaurate, and 13 parts of a modified monomer were mixed, and the temperature was raised to 95° C. under a protective atmosphere, and the mixture was reacted for 2.5 hours, and then cooled to room temperature to obtain a prepolymer;

[0071] Step 2: 13.5 parts of prepolymer, 9 parts of tetrafluorobutanediol, and 17.5 parts of dibutyltin dilaurate were mixed, heated to 82.5°C for reaction for 1.5 hours, cooled to 55°C, 1,4-butanediol and 3.5 parts of dimethylthiotoluenediamine were added for chain extension for 25 minutes, cooled to 40°C, neutralized, filtered and washed to obtain a modified polyurethane;

[0072] Wherein, the preparation process of the modified monomer is:

[0073] S1: 120 parts of tetrahydrofuran, 11 parts of magnesium, and 2.5 parts of iodine were mixed and stirred at 57.5°C for 1.5 hours, followed by slow addition of 26.5 parts of 4-bromobiphenyl and reflux stirring for 1.5 hours. After cooling, the resulting mixture was mixed with 11 parts of trichlorocyanuric acid and 120 parts of tetrahydrofuran, the temperature was raised to 45°C, the reaction was continued for 1.5 hours, the solvent was evaporated under reduced pressure, extraction was performed, drying was performed, and purification was performed to obtain biphenyltriazine;

[0074] S2: 13 parts of biphenyltriazine, acetone, 6.5 parts of 3-allyl-2-hydroxybenzaldehyde, and 0.65 parts of sodium hydroxide were mixed, the temperature was raised to 55°C, and the reaction was carried out for 3.5 hours. After post-treatment, the mixture was transferred to 90 parts of toluene, 3.5 parts of 4-(bromomethyl)aniline were added, the temperature was raised to 70°C, and the reaction was continued for 3.5 hours. After natural cooling, the mixture was filtered, washed, and dried; the mixture was transferred to a round-bottom flask, 55 parts of anhydrous ethanol and 1.5 parts of sodium borohydride were added, and magnetic stirring was carried out at room temperature until no bubbles overflowed. The reaction was continued for 1.5 hours, the solvent was distilled off under reduced pressure, 90 parts of water were added, the mixture was filtered, and dried to obtain intermediate A;

[0075] S3: 9 parts of intermediate A, 3 parts of triphenylphosphine and 90 parts of toluene were mixed, the temperature was raised to 55°C, and the mixture was stirred and reacted for 6.5 hours. After the reaction was completed, the solvent was removed by distillation under reduced pressure. After purification, the mixture was transferred to 70 parts of acetone. Under a protective atmosphere, 1.5 parts of 1-thioglycerol and 0.65 parts of azobisisobutyronitrile solution were added. The temperature was raised to 75°C, the mixture was reacted for 3.5 hours, and the mixture was cooled to room temperature. The mixture was filtered, washed and dried to obtain a modified monomer.

[0076] Testing: (1) The cables prepared in the examples and comparative examples were tested for their elongation at break and tensile strength using the national standard GB / T1040; (2) The cables prepared in the examples and comparative examples were rolled on a round rod and placed in an oven at 130°C for 24 hours. After being taken out, the cables were tested for cracking or breakage; (3) The cables prepared in the examples and comparative examples were hung on a rotating wheel, first rotated 1080° clockwise and then returned to the initial state, then twisted 1080° counterclockwise and returned to the initial state, at a rotation speed of 360° / min. This constituted one cycle, and a total of 3000 cycles were repeated to check for cracking. The data obtained are shown in the following table:

[0077]

[0078] Table 1

[0079] Conclusion: The present invention significantly improves the performance of cables for wind power generation by introducing modified monomers into the polyurethane system and optimizing the preparation process of the composite inorganic filler. Specifically, the cables of Examples 1 to 3 performed well in terms of elongation at break and tensile strength, reaching elongations at break of 780%, 765%, and 789%, and tensile strengths of 25.8 MPa, 26.8 MPa, and 28.7 MPa, respectively. These are much higher than the elongations at break of 653% and 630% and tensile strengths of 14.5 MPa and 12.8 MPa, respectively, of Comparative Examples 1 and 2. In addition, after being placed in a 130°C oven for 24 hours, the cables of the examples did not crack, while the cables of the comparative examples did crack; in the torsion resistance test, the cables of the examples did not change after 3,000 cycles of torsion, while the cables of the comparative examples did crack. These data indicate that the introduction of modified monomers and surface functionalization modification of kaolinite effectively enhance the mechanical strength, torsional resistance and heat resistance of the cable, making it more reliable and stable under complex working conditions.

[0080] Throughout the specification, references to terms such as "one embodiment," "example," or "specific example" indicate that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, schematic representations of these terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0081] The above contents are merely examples and explanations of the present invention. Those skilled in the art may make various modifications or additions to the described specific embodiments or replace them in similar ways. As long as they do not deviate from the invention or exceed the scope defined by the claims, they should all fall within the scope of protection of the present invention.

Claims

1. A high-toughness, torsion-resistant cable for wind power generation, characterized by: The cable comprises a conductor, an isolation layer, an insulating layer and a protective layer in order from the inside out; the protective layer comprises the following components: by weight, 100-120 parts of modified polyurethane, 10-12 parts of composite inorganic filler, 2-3 parts of antioxidant, 1-2 parts of plasticizer and 1-2 parts of antioxidant.

2. The high-toughness torsion-resistant cable for wind power generation according to claim 1, characterized in that: The preparation process of the modified polyurethane is: Step 1: Mix polytetrahydrofuran, modified monomer, 1,6-hexamethylene diisocyanate, and dibutyltin dilaurate, raise the temperature to 90-100°C under a protective atmosphere, react for 2-3 hours, and cool to room temperature to obtain a prepolymer; Step 2: Mix the prepolymer, tetrafluorobutanediol, and dibutyltin dilaurate, heat to 80-85°C and react for 1-2 hours, cool to 50-60°C, add 1,4-butanediol and dimethylthiotoluene diamine to extend the chain for 20-30 minutes, cool to 40°C, neutralize, filter and wash to obtain modified polyurethane.

3. The high-toughness torsion-resistant cable for wind power generation according to claim 2, characterized in that: The prepolymer comprises the following components, by weight: 20-22 parts of polytetrahydrofuran, 10-15 parts of 1,6-hexamethylene diisocyanate, 8-10 parts of dibutyltin dilaurate, and 12-14 parts of a modified monomer; the modified polyurethane raw material comprises the following components, by weight: 12-15 parts of a prepolymer, 8-10 parts of tetrafluorobutanediol, 15-20 parts of dibutyltin dilaurate, 4-7 parts of 1,4-butanediol, and 2-5 parts of dimethylthiotoluenediamine.

4. The high-toughness torsion-resistant cable for wind power generation according to claim 2, characterized in that: The preparation process of the modified monomer is: S1: Tetrahydrofuran, magnesium, and iodine are mixed and stirred at 55-60°C for 1-2 hours, followed by the slow addition of 4-bromobiphenyl and the mixture is refluxed and stirred for 1-2 hours. After cooling, the resulting mixture is mixed with trichlorocyanuric acid and tetrahydrofuran, and the temperature is raised to 40-50°C. The reaction is continued for 1-2 hours, and the solvent is evaporated under reduced pressure. The mixture is extracted, dried, and purified to obtain biphenyltriazine. S2: Biphenyltriazine, acetone, 3-allyl-2-hydroxybenzaldehyde, and sodium hydroxide were mixed, the temperature was raised to 50-60°C, the reaction was continued for 3-4 hours, and after post-treatment, the mixture was transferred to toluene, 4-(bromomethyl)aniline was added, the temperature was raised to 60-80°C, the reaction was continued for 3-4 hours, and the mixture was naturally cooled and filtered, washed, and dried; the mixture was transferred to a round-bottom flask, anhydrous ethanol and sodium borohydride were added, and magnetic stirring was performed at room temperature until no bubbles overflowed. The reaction was continued for 1-2 hours, the solvent was distilled off under reduced pressure, water was added, the mixture was filtered, and dried to obtain intermediate A; S3: Mix intermediate A, triphenylphosphine and toluene, increase the temperature to 50-60°C, and stir to react for 6-7 hours. After the reaction is completed, remove the solvent by distillation under reduced pressure. After purification, transfer to acetone. Under a protective atmosphere, add 1-thioglycerol and azobisisobutyronitrile solution, increase the temperature to 70-80°C, react for 3-4 hours, cool to room temperature, filter, wash, and dry to obtain a modified monomer.

5. The high-toughness torsion-resistant cable for wind power generation according to claim 4, characterized in that: The biphenyltriazine raw material comprises the following components: by weight, 200-280 parts of tetrahydrofuran, 10-12 parts of magnesium, 2-3 parts of iodine, 25-28 parts of 4-bromobiphenyl, and 10-12 parts of trichlorocyanuric acid.

6. The high-toughness torsion-resistant cable for wind power generation according to claim 4, characterized in that: The intermediate A raw material includes the following components: by weight, 12-14 parts of biphenyltriazine, acetone, 5-8 parts of 3-allyl-2-hydroxybenzaldehyde, 0.5-0.8 parts of sodium hydroxide, 80-100 parts of toluene, 3-4 parts of 4-(bromomethyl)aniline, 50-60 parts of anhydrous ethanol, 1-2 parts of sodium borohydride, and 80-100 parts of water.

7. The high-toughness torsion-resistant cable for wind power generation according to claim 4, characterized in that: The modified monomer comprises the following components: by weight, 8-10 parts of intermediate A, 2-4 parts of triphenylphosphine, 80-100 parts of toluene, 60-80 parts of acetone, 1-2 parts of 1-thioglycerol, and 0.5-0.8 parts of azobisisobutyronitrile solution.

8. The high-toughness torsion-resistant cable for wind power generation according to claim 1, characterized in that: The composite inorganic filler comprises modified kaolinite and hydroxylated carbon nanotubes in a mass ratio of 1:(5-6).

9. The high-toughness torsion-resistant cable for wind power generation according to claim 8, characterized in that: The preparation process of the modified kaolinite is as follows: under a nitrogen atmosphere, dispersing kaolinite in N,N-dimethylformamide, adding prepolymer, stirring at 60-65° C. for 5-6 hours, cooling, filtering, and drying to obtain the modified kaolinite.

10. The high-toughness torsion-resistant cable for wind power generation according to claim 9, characterized in that: The modified kaolinite comprises the following components: by weight, 15-18 parts of kaolinite, 60-80 parts of N,N-dimethylformamide, and 3-5 parts of prepolymer.

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