Cable polymer composite material for wind power blade

Abstract

The invention relates to the technical field of polymer composite materials, in particular to a cable polymer composite material for a wind turbine blade, which is prepared from the following raw materials in parts by weight: a polymer base material; a reinforcing material; a polymer modified material; a functional additive; a performance modifier; the functional additive is prepared from an anti-ultraviolet agent, an antioxidant, a silane coupling agent and nano titanium dioxide. According to the invention, the epoxy modified polyether-ether-ketone and bisphenol A epoxy resin compounded base material is matched with a continuous glass fiber, carbon fiber chopped strand and nano silicon nitride multi-element reinforcing system, so that the core short board of insufficient mechanical properties of the traditional material is thoroughly solved, and a magnesium hydroxide, aluminum hydroxide, expanded graphite and nano montmorillonite compounded flame-retardant system is also selected, so that the flame-retardant performance of the material is greatly improved. The flame-retardant cable material is high in flame retardance, free of toxic gas release, capable of meeting the environment-friendly requirement, capable of improving the material interface bonding force and long-term service reliability and capable of meeting the requirement for the service life of 20 years or above of wind power blade cables.

Description

Technical Field

[0001] This invention relates to the field of polymer composite materials technology, specifically to a polymer composite material for cables used in wind turbine blades. Background Technology

[0002] Wind turbine blade cables are core connection components of wind power equipment. They need to be used in extreme outdoor environments for a long time, facing complex conditions such as strong ultraviolet radiation, high and low temperature cycles, high humidity, and alternating loads. This places stringent requirements on the mechanical properties, weather resistance, flame retardancy, dimensional stability, and long-term service reliability of the materials.

[0003] However, traditional cable polymer composite materials typically use polyolefins and ordinary rubber as base materials, combined with conventional inorganic fillers. Their design focuses on insulation and laying flexibility, resulting in insufficient mechanical properties. Tensile strength is usually only 10-30 MPa, and flexural modulus is 100-1000 MPa. They cannot withstand the centrifugal force and aerodynamic loads generated by blade rotation, exhibit poor fatigue resistance, and are prone to cracking and failure under long-term alternating loads. Furthermore, they have weak weather resistance, poor compatibility with UV and antioxidant systems, and are prone to aging and embrittlement after long-term outdoor exposure. Tensile strength retention is less than 70%, and dimensional stability is poor, with a linear expansion coefficient as high as 10-20 × 10⁻⁻⁻⁻⁶. 5 / ℃, when the temperature changes, it is easy to generate internal stress with the main structure of the blade, leading to adhesion and delamination. Among them, there is a contradiction between flame retardancy and environmental protection. Traditional bromine-based flame retardants release toxic gases at high temperatures, and excessive addition of inorganic flame retardants will deteriorate the toughness of the material, resulting in poor processing and molding uniformity, easy generation of agglomerated particles and internal defects, and affecting long-term use stability.

[0004] Based on this, the present invention provides a polymer composite material for cables used in wind turbine blades to solve the aforementioned technical problems. Summary of the Invention

[0005] The purpose of this invention is to provide a polymer composite material for cables used in wind turbine blades, thereby solving the problems mentioned in the background section.

[0006] To achieve the above objectives, the present invention provides the following technical solution: This invention proposes a polymer composite material for cables used in wind turbine blades, which is composed of the following raw materials in parts by weight: polymer matrix: 45-60 parts; reinforcing material: 25-38 parts; polymer modified material: 5-9 parts; functional additives: 3-6.5 parts; performance regulators: 1.2-2.8 parts; auxiliary functional materials: 4-8 parts; The functional additive is composed of an anti-ultraviolet agent, an antioxidant, a silane coupling agent, and nano-titanium dioxide, wherein the anti-ultraviolet agent is 0.5-1 part, the antioxidant is 0.8-1.5 parts, the silane coupling agent is 0.7-1.2 parts, and the nano-titanium dioxide is 1-2.8 parts. The UV inhibitor is composed of 2-hydroxy-4-n-octyloxybenzophenone and bis(2,2,6,6-tetramethylpiperidinyl) sebacate in a mass ratio of 1:1.2; The antioxidant is composed of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and N,N'-bis-(1-naphthyl)-p-phenylenediamine in a mass ratio of 2:1. The silane coupling agent is γ-aminopropyltriethoxysilane; The particle size of the nano-titanium dioxide is 20-50 nm.

[0007] Preferably, the polymer substrate is composed of epoxy-modified polyether ether ketone and bisphenol A type epoxy resin, wherein the epoxy-modified polyether ether ketone comprises 30-42 parts and the bisphenol A type epoxy resin comprises 15-18 parts.

[0008] Preferably, the reinforcing material is composed of continuous glass fiber, chopped carbon fiber filaments, and nano-silicon nitride, wherein the continuous glass fiber comprises 18-25 parts, the chopped carbon fiber filaments comprise 6-10 parts, and the nano-silicon nitride comprises 1-3 parts.

[0009] Preferably, the polymer-modified material is composed of hydroxyl-terminated polybutadiene and fluorocarbon resin, wherein the hydroxyl-terminated polybutadiene comprises 3-5 parts and the fluorocarbon resin comprises 2-4 parts.

[0010] Preferably, the performance modifier is composed of polyetheretherketone wax, polyimide micro powder and titanate coupling agent, wherein the polyetheretherketone wax is 0.5-1 parts, the polyimide micro powder is 0.4-0.9 parts, and the titanate coupling agent is 0.3-0.9 parts.

[0011] Preferably, the fluorocarbon resin is composed of tetrafluoroethylene, hexafluoropropylene and vinylidene fluoride through a free radical copolymerization reaction, and the main chain contains fluorine atomic mass fraction ≥60%.

[0012] Preferably, the auxiliary functional material is composed of magnesium hydroxide, aluminum hydroxide, expanded graphite, and nano-montmorillonite, wherein the magnesium hydroxide content is 1.5-2.5 parts, the aluminum hydroxide content is 1-2 parts, the expanded graphite content is 0.8-1.5 parts, and the nano-montmorillonite content is 0.7-2 parts.

[0013] Based on the above-mentioned polymer composite material, the present invention also proposes a method for preparing a polymer composite material for cables used in wind turbine blades, comprising the following steps: S1. Place 30-42 parts of epoxy-modified polyetheretherketone (PEEK) and 15-18 parts of bisphenol A epoxy resin into a vacuum drying oven and dry at 120-140℃ for 4-6 hours, controlling the moisture content to ≤0.3%; after surface degreasing treatment, 18-25 parts of continuous glass fiber (reinforcing material) are dried at 80-100℃ for 2-3 hours; 6-10 parts of chopped carbon fiber are soaked in a 5% silane coupling agent solution for 30 minutes, then dried at 110℃ for 1.5 hours; 1-3 parts of nano-silicon nitride are pulverized by airflow to a particle size ≤500nm; 3-5 parts of hydroxyl-terminated polybutadiene (P&B) and 2-4 parts of fluorocarbon resin (P&B modified material) are stored at a constant temperature of 25±3℃ to avoid stratification. S2. Add the dried polymer substrate, treated reinforcing material, functional additives (0.5-1 part UV stabilizer, 0.8-1.5 part antioxidant, 0.7-1.2 part silane coupling agent, 1-2.8 parts nano titanium dioxide), and auxiliary functional materials (1.5-2.5 parts magnesium hydroxide, 1-2 parts aluminum hydroxide, 0.8-1.5 parts expanded graphite, and 0.7-2 parts nano montmorillonite) to a high-speed mixer and mix in three stages: Coarse mixing: Stir at 300-400 rpm for 5 minutes to eliminate raw material accumulation; Fine mixing: Stir at 600-800 r / min for 12 min, then add 3-5 parts of hydroxyl-terminated polybutadiene and 2-4 parts of fluorocarbon resin; Homogenization: Stir at 1200-1500 r / min for 8 min, and use an online particle size analyzer to ensure that the agglomerated particle size is ≤10μm and the mixing uniformity is ≥99%. S3. Add 0.5-1 parts of performance regulator polyether ether ketone wax, 0.4-0.9 parts of polyimide micro powder, 0.3-0.9 parts of titanate coupling agent and deionized water to a static mixer at a mass ratio of 1:5, control the water temperature at 25-30℃, and stir for 15 minutes to premix into a homogeneous solution. S4. The mixed dry powder obtained in step S2 and the liquid performance regulator solution prepared in step S3 are fed into a twin-screw extruder at a mass ratio of 100:8-12. The screw speed is 80-120 r / min. After extrusion, the mixture is cooled and pelletized by water to obtain composite material particles with a particle size of 2-4 mm. S5. Feed the composite material particles into the vacuum injection molding machine. For the molding requirements of wind turbine blade cable sheath, control the injection temperature to 240-260℃, the injection pressure to 80-100MPa, the holding pressure to 60-70MPa, the holding time to 15-20s, the mold temperature to 80-100℃, and allow it to cool naturally to room temperature for 30-40min. S6. Post-treatment and curing: Place the molded composite material product in a UV aging chamber and pre-treat it for 48 hours under UV light intensity of 30W / m², temperature of 60℃, and humidity of 50%; then transfer it to a humid heat curing chamber and cure it for 7 days under temperature of 40℃ and humidity of 90%, monitoring the surface condition of the product daily; finally, perform low-temperature aging treatment, keeping it at -40℃ for 24 hours, and then naturally warming it to room temperature to complete the post-treatment. S7. The polymer composite material for wind turbine blades prepared in steps S1 to S6 is subjected to performance testing and packaged. The testing items include tensile strength, flexural modulus, fatigue resistance, UV aging resistance, flame retardancy, dimensional stability and damp heat resistance.

[0014] Preferably, the extrusion temperature in step S4 is controlled in stages as follows: 160-180℃ in the feeding section, 200-220℃ in the compression section, 230-250℃ in the melting section, and 220-230℃ in the die head section.

[0015] Compared with the prior art, the beneficial effects of the present invention are: This invention uses epoxy-modified polyetheretherketone and bisphenol A type epoxy resin as a composite base material, combined with a multi-element reinforcement system of continuous glass fiber, carbon fiber short filaments and nano-silicon nitride. Its comprehensive performance is completely superior to traditional materials, thoroughly solving the core shortcoming of insufficient mechanical properties of traditional materials. Furthermore, through the synergistic effect of UV stabilizers and antioxidants in a specific ratio, it achieves higher resistance to UV aging and damp heat, effectively resisting the corrosion of extreme outdoor environments. It also uses a composite flame retardant system of magnesium hydroxide, aluminum hydroxide, expanded graphite and nano-montmorillonite, which has higher flame retardant performance and no toxic gas release, meeting green environmental protection requirements. It improves the interfacial bonding strength and long-term service reliability of the material, and is suitable for the service life requirement of wind turbine blade cables of more than 20 years. Detailed Implementation

[0016] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. 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 of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0017] I. Materials: Unless otherwise specified, all components of the polymer composite material formulation for wind turbine blade cables in this invention are commercially available. This invention proposes a polymer composite material for cables used in wind turbine blades, which is composed of the following raw materials in parts by weight: polymer matrix: 45-60 parts; reinforcing material: 25-38 parts; polymer modified material: 5-9 parts; functional additives: 3-6.5 parts; performance regulators: 1.2-2.8 parts; auxiliary functional materials: 4-8 parts.

[0018] It should be noted that the functional additives consist of UV stabilizers, antioxidants, silane coupling agents, and nano-titanium dioxide. The UV stabilizer comprises 0.5-1 parts, the antioxidant 0.8-1.5 parts, the silane coupling agent 0.7-1.2 parts, and the nano-titanium dioxide 1-2.8 parts. The UV stabilizer is composed of 2-hydroxy-4-n-octyloxybenzophenone and bis(2,2,6,6-tetramethylpiperidinyl) sebacate in a mass ratio of 1:1.2. The antioxidant is composed of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and N,N'-bis-(1-naphthyl)-p-phenylenediamine in a mass ratio of 2:1. The silane coupling agent is γ-aminopropyltriethoxysilane. The nano-titanium dioxide has a particle size of 20-50 nm.

[0019] It should be noted that the polymer substrate is composed of epoxy-modified polyether ether ketone and bisphenol A type epoxy resin, with epoxy-modified polyether ether ketone comprising 30-42 parts and bisphenol A type epoxy resin comprising 15-18 parts.

[0020] It should be noted that the reinforcing material is composed of continuous glass fiber, chopped carbon fiber filaments and nano-silicon nitride, with continuous glass fiber: 18-25 parts, chopped carbon fiber filaments: 6-10 parts, and nano-silicon nitride: 1-3 parts.

[0021] It should be noted that the polymer-modified material is composed of hydroxyl-terminated polybutadiene and fluorocarbon resin, with 3-5 parts of hydroxyl-terminated polybutadiene and 2-4 parts of fluorocarbon resin. The fluorocarbon resin is composed of tetrafluoroethylene, hexafluoropropylene and vinylidene fluoride through a free radical copolymerization reaction, and the main chain contains ≥60% fluorine atomic mass fraction.

[0022] It should be noted that the performance modifier is composed of polyetheretherketone wax, polyimide micro powder and titanate coupling agent, with polyetheretherketone wax: 0.5-1 parts, polyimide micro powder: 0.4-0.9 parts, and titanate coupling agent: 0.3-0.9 parts.

[0023] It should be noted that the auxiliary functional materials are composed of magnesium hydroxide, aluminum hydroxide, expanded graphite, and nano-montmorillonite, with magnesium hydroxide: 1.5-2.5 parts, aluminum hydroxide: 1-2 parts, expanded graphite: 0.8-1.5 parts, and nano-montmorillonite: 0.7-2 parts.

[0024] II. Process: Based on the above formulation, the present invention also proposes a method for preparing a polymer composite material for wind turbine blade cables, specifically including the following steps: S1. Place 30-42 parts of epoxy-modified polyetheretherketone (PEEK) and 15-18 parts of bisphenol A epoxy resin into a vacuum drying oven and dry at 120-140℃ for 4-6 hours, controlling the moisture content to ≤0.3%; after surface degreasing treatment, 18-25 parts of continuous glass fiber (reinforcing material) are dried at 80-100℃ for 2-3 hours; 6-10 parts of chopped carbon fiber are soaked in a 5% silane coupling agent solution for 30 minutes, then dried at 110℃ for 1.5 hours; 1-3 parts of nano-silicon nitride are pulverized by airflow to a particle size ≤500nm; 3-5 parts of hydroxyl-terminated polybutadiene (P&B) and 2-4 parts of fluorocarbon resin (P&B modified material) are stored at a constant temperature of 25±3℃ to avoid stratification. S2. Add the dried polymer substrate, treated reinforcing material, functional additives (0.5-1 part UV stabilizer, 0.8-1.5 part antioxidant, 0.7-1.2 part silane coupling agent, 1-2.8 parts nano titanium dioxide, and auxiliary functional materials (1.5-2.5 parts magnesium hydroxide, 1-2 parts aluminum hydroxide, 0.8-1.5 parts expanded graphite, and 0.7-2 parts nano montmorillonite) to a high-speed mixer and mix in three stages: Coarse mixing: 300-400 r / min, stirring for 5 min to eliminate raw material accumulation; Fine mixing: 600-800 r / min, stirring for 12 min, adding 3-5 parts of polymer modifier (hydroxyl-terminated polybutadiene) and 2-4 parts of fluorocarbon resin; Homogenization: 1200-1500 r / min, stirring for 8 min. Use an online particle size analyzer to ensure that the agglomerated particle size is ≤10 μm and the mixing uniformity is ≥99%. S3. Add 0.5-1 parts of performance regulator polyether ether ketone wax, 0.4-0.9 parts of polyimide micro powder, 0.3-0.9 parts of titanate coupling agent and deionized water to a static mixer at a mass ratio of 1:5, control the water temperature at 25-30℃, and stir for 15 minutes to premix into a homogeneous solution. S4. The mixed dry powder obtained in step S2 and the liquid performance regulator solution prepared in step S3 are fed into a twin-screw extruder at a mass ratio of 100:8-12. The extrusion temperature is controlled in stages: 160-180℃ in the feeding section, 200-220℃ in the compression section, 230-250℃ in the melting section, and 220-230℃ in the die head section. The screw speed is 80-120 r / min. After extrusion, the material is water-cooled and pelletized to obtain composite material particles with a particle size of 2-4 mm. S5. Feed the composite material particles into the vacuum injection molding machine. For the molding requirements of wind turbine blade cable sheath, control the injection temperature to 240-260℃, the injection pressure to 80-100MPa, the holding pressure to 60-70MPa, the holding time to 15-20s, the mold temperature to 80-100℃, and allow it to cool naturally to room temperature for 30-40min. S6. Post-treatment and curing: Place the molded composite material product in a UV aging chamber and pre-treat it for 48 hours under UV light intensity of 30W / m², temperature of 60℃, and humidity of 50%; then transfer it to a humid heat curing chamber and cure it for 7 days under temperature of 40℃ and humidity of 90%, monitoring the surface condition of the product daily; finally, perform low-temperature aging treatment, keeping it at -40℃ for 24 hours, and then naturally warming it to room temperature to complete the post-treatment. S7. The polymer composite material for wind turbine blades prepared in steps S1 to S6 is subjected to performance testing and packaged. The testing items include tensile strength, flexural modulus, fatigue resistance, UV aging resistance, flame retardancy, dimensional stability and damp heat resistance.

[0025] Example 1: In this example, a polymer composite material for wind turbine blade cables was prepared according to the following process. The formulation components are as follows: Polymer matrix: 36 parts epoxy-modified polyetheretherketone, 16.5 parts bisphenol A type epoxy resin; Reinforcing materials: 21 parts continuous glass fiber, 8 parts chopped carbon fiber, 2 parts nano-silicon nitride; Polymer modifying materials: 4 parts hydroxyl-terminated polybutadiene, 3 parts fluorocarbon resin; Functional additives: 0.8 parts UV stabilizer (0.36 parts 2-hydroxy-4-n-octyloxybenzophenone, bis(2,2,6,6-tetramethylpiperidine)). The composition includes: 0.44 parts of β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, 1.2 parts of antioxidant (0.8 parts of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, 0.4 parts of N,N'-bis-(1-naphthyl)-p-phenylenediamine), 0.9 parts of silane coupling agent, and 2 parts of nano-titanium dioxide; performance modifiers: 0.7 parts of polyether ether ketone wax, 0.6 parts of polyimide micro powder, and 0.6 parts of titanate coupling agent; auxiliary functional materials: 2 parts of magnesium hydroxide, 1.5 parts of aluminum hydroxide, 1.2 parts of expanded graphite, and 1.3 parts of nano-montmorillonite; The preparation process includes the following steps: Step S1: Epoxy-modified polyetheretherketone and bisphenol A type epoxy resin are vacuum dried at 130℃ for 5 hours, with a moisture content of 0.2%; continuous glass fiber is degreased and dried at 90℃ for 2.5 hours; carbon fiber short filaments are soaked in 5% silane coupling agent solution for 30 minutes and then dried at 110℃ for 1.5 hours; nano-silicon nitride is air-jet pulverized to a particle size of 400nm; hydroxyl-terminated polybutadiene and fluorocarbon resin are stored at a constant temperature of 25℃. Step S2: The high-speed mixer is used for coarse mixing at 350 r / min and stirring for 5 min, fine mixing at 700 r / min and stirring for 12 min, and homogenization at 1300 r / min and stirring for 8 min. The mixing uniformity is 99.5%, and the particle size of the agglomerated particles is 8 μm. Step S3: Mix the performance regulator with deionized water at a ratio of 1:5, at a water temperature of 28°C, and stir for 15 minutes to form a homogeneous solution; Step S4: Mix the dry powder and liquid performance regulator solution at a ratio of 100:10 and feed them into a twin-screw extruder. The temperature is 170°C in the feeding section, 210°C in the compression section, 240°C in the melting section, and 225°C in the die head section. The screw speed is 100 r / min and the pellet size is 3 mm. Step S5: Vacuum injection temperature 250℃, injection pressure 90MPa, holding pressure 65MPa, holding time 18s, mold temperature 90℃, cooling time 35min; Step S6: UV aging pretreatment for 48 hours, humid heat curing for 7 days, and low temperature aging for 24 hours.

[0026] Example 2: In this example, the polymer substrate consists of 30 parts epoxy-modified polyetheretherketone and 15 parts bisphenol A type epoxy resin; the reinforcing materials are 18 parts continuous glass fiber, 6 parts chopped carbon fiber filaments, and 1 part nano-silicon nitride; the polymer modifying materials are 3 parts hydroxyl-terminated polybutadiene and 2 parts fluorocarbon resin; the functional additives are 0.5 parts UV stabilizer (0.23 parts 2-hydroxy-4-n-octyloxybenzophenone and 0.27 parts bis(2,2,6,6-tetramethylpiperidinyl) sebacate) and 0.8 parts antioxidant (tetramethylpiperidinyl sebacate). [β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid] pentaerythritol ester 0.53 parts, N,N'-bis-(1-naphthyl)-p-phenylenediamine 0.27 parts, silane coupling agent 0.7 parts, nano titanium dioxide 1 part; performance modifiers: polyether ether ketone wax 0.5 parts, polyimide micro powder 0.4 parts, titanate coupling agent 0.3 parts; auxiliary functional materials: magnesium hydroxide 1.5 parts, aluminum hydroxide 1 part, expanded graphite 0.8 parts, nano montmorillonite 0.7 parts; other process parameters are the same as in Example 1.

[0027] Example 3: In this example, the polymer substrate consists of 42 parts epoxy-modified polyetheretherketone and 18 parts bisphenol A type epoxy resin; the reinforcing materials are 25 parts continuous glass fiber, 10 parts chopped carbon fiber filaments, and 3 parts nano-silicon nitride; the polymer modifying materials are 5 parts hydroxyl-terminated polybutadiene and 4 parts fluorocarbon resin; the functional additives are 1 part UV stabilizer (0.45 parts 2-hydroxy-4-n-octyloxybenzophenone and 0.55 parts bis(2,2,6,6-tetramethylpiperidinyl) sebacate) and 1.5 parts antioxidant. (1 part of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, 0.5 parts of N,N'-bis-(1-naphthyl)-p-phenylenediamine), 1.2 parts of silane coupling agent, 2.8 parts of nano titanium dioxide; performance modifiers: 1 part of polyether ether ketone wax, 0.9 parts of polyimide micro powder, 0.9 parts of titanate coupling agent; auxiliary functional materials: 2.5 parts of magnesium hydroxide, 2 parts of aluminum hydroxide, 1.5 parts of expanded graphite, 2 parts of nano montmorillonite; other process parameters are the same as in Example 1.

[0028] Comparative Example 1: In this comparative example, the reinforcing material is 15 parts of continuous glass fiber, and the other components and process parameters are the same as in Example 1.

[0029] Comparative Example 2: In this comparative example, the amount of UV protectant was 1.5 parts, and the other components and process parameters were the same as in Example 1.

[0030] Comparative Example 3: In this comparative example, the polymer substrate epoxy-modified polyether ether ketone was 45 parts, and other components and process parameters were the same as in Example 1.

[0031] The components of the examples and comparative formulations are shown in Table 1: Table 1: Components of the Examples and Comparative Examples (Unit: Parts)

[0032] III. Performance Testing: The following performance tests were performed on the cable polymer composite materials for wind turbine blades prepared in the examples and comparative examples: a. Tensile strength is tested according to GB / T1040 standard; b. Flexural modulus is tested according to GB / T9341 standard; c. Fatigue resistance was tested according to GB / T3075 standard (10). 7 Sub-alternating load); d. Test the UV aging resistance (tensile strength retention rate after 1000 hours) according to GB / T16422.2 standard; e. Flame retardant performance is tested according to UL94 standard; f. The linear expansion coefficient at -40℃ to 60℃ is tested according to GB / T1036 standard; g. Test the resistance to damp heat (bonding strength after 1000 hours) according to GB / T14623.2 standard; h. Test the impact strength according to GB / T1843 standard; i. Test the heat distortion temperature according to GB / T1634.2 standard.

[0033] Performance data for the examples and comparative examples are shown in Table 2: Table 2: Performance Data of Examples and Comparative Examples

[0034] IV. Analysis Conclusion: As shown in Tables 1 and 2, in Comparative Example 1, the amount of continuous glass fiber was below the lower limit of the formulation range, resulting in insufficient reinforcement. Tensile strength decreased by 26.3%, flexural modulus decreased by 35.7%, impact strength decreased by 26.3%, and flame retardancy dropped to V-1 level. This verifies the crucial influence of the reinforcement material dosage range on mechanical and flame retardant properties. In Comparative Example 2, the amount of UV stabilizer exceeded the upper limit of the formulation range. Excessive UV stabilizer resulted in poor compatibility with the substrate, leading to a 13.7% decrease in UV aging resistance and a 15.8% decrease in tensile strength. This indicates that UV stabilizers need to be compounded within a reasonable range to achieve a synergistic effect. In Comparative Example 3, the amount of epoxy-modified polyetheretherketone exceeded the upper limit of the formulation range, resulting in poor material processing fluidity, decreased internal uniformity, a 18.4% decrease in tensile strength, a 21.4% decrease in flexural modulus, and a 22.6% decrease in damp heat resistance. This demonstrates that the proportion of polymer substrate needs to be strictly controlled to balance processability and performance.

[0035] Based on the data from the examples, Example 1 uses the intermediate ratio of each component. The epoxy-modified polyetheretherketone and bisphenol A epoxy resin work synergistically to provide substrate support. Continuous glass fiber, chopped carbon fiber filaments, and nano-silicon nitride form a multi-element reinforcing network. The ratio of UV stabilizer to antioxidant is optimal, and all properties reach the best level: tensile strength 380 MPa, flexural modulus 28 GPa, UV aging resistance retention rate 95%, and damp heat adhesion strength 6.2 MPa, fully demonstrating the advantages of the synergistic effect of each component. Example 2 uses the lower limit ratio of each component, and the performance meets the basic usage requirements. Example 3 uses the upper limit ratio of each component, and the performance is close to that of Example 1 but not further improved. This indicates that the formulation range design of the present invention is scientific and reasonable, and performance optimization can be achieved without excessive addition of components.

[0036] This invention achieves a comprehensive improvement in the mechanical properties, weather resistance, flame retardancy, and dimensional stability of polymer composite materials for wind turbine blade cables by precisely controlling the proportions of each component and process parameters, thus overcoming the defects of traditional materials and making them suitable for the extreme working environments of wind turbine blades.

[0037] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above 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 one or more embodiments or examples.

[0038] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A cable polymer composite for wind turbine blades, characterized in that, It is composed of the following weight parts of raw materials: high molecular matrix: 45-60 parts; reinforcing material: 25-38 parts; polymer modification material: 5-9 parts; functional additives: 3-6.5 parts; performance regulator: 1.2-2.8 parts; auxiliary functional material: 4-8 parts; The functional additives are composed of ultraviolet resistance agent, antioxidant, silane coupling agent and nano titanium dioxide, the ultraviolet resistance agent: 0.5-1 part, the antioxidant: 0.8-1.5 parts, the silane coupling agent: 0.7-1.2 parts, the nano titanium dioxide: 1-2.8 parts; The ultraviolet resistance agent is composed of 2-hydroxy-4-n-octyloxybenzophenone and bis(2,2,6,6-tetramethylpiperidyl) sebacate with a mass ratio of 1:1.2; The antioxidant is composed of tetra[β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionic acid] pentaerythritol ester and N,N'-bis-(1-naphthyl)-p-phenylenediamine with a mass ratio of 2:1; The silane coupling agent is γ-aminopropyl triethoxysilane; The particle size of the nano titanium dioxide is 20-50 nm.

2. The cable polymer composite for wind turbine blades according to claim 1, characterized in that, The high molecular matrix is composed of epoxy modified polyether ether ketone and bisphenol A type epoxy resin, the epoxy modified polyether ether ketone: 30-42 parts, the bisphenol A type epoxy resin: 15-18 parts.

3. The cable polymer composite for wind turbine blades according to claim 2, characterized in that, The reinforcing material is composed of continuous glass fiber, carbon fiber short cut silk and nano silicon nitride, the continuous glass fiber: 18-25 parts, the carbon fiber short cut silk: 6-10 parts, the nano silicon nitride: 1-3 parts.

4. The cable polymer composite for wind turbine blades according to claim 3, characterized in that, The polymer modification material is composed of hydroxyl-terminated polybutadiene and fluorocarbon resin, the hydroxyl-terminated polybutadiene: 3-5 parts, the fluorocarbon resin: 2-4 parts.

5. The cable polymer composite for wind turbine blades according to claim 4, characterized in that, The performance regulator is composed of polyether ether ketone wax, polyimide micro powder and titanate coupling agent, the polyether ether ketone wax: 0.5-1 part, the polyimide micro powder: 0.4-0.9 part, the titanate coupling agent: 0.3-0.9 part.

6. The cable polymer composite for wind turbine blades according to claim 5, characterized in that, The fluorocarbon resin is composed of tetrafluoroethylene, hexafluoropropylene and vinylidene fluoride by free radical copolymerization, the main chain contains fluorine atom mass fraction ≥60%.

7. A cable polymer composite for wind turbine blades according to claim 6, characterized in that The auxiliary functional material is composed of magnesium hydroxide, aluminum hydroxide and expanded graphite, nano montmorillonite, the magnesium hydroxide: 1.5-2.5 parts, the aluminum hydroxide: 1-2 parts, the expanded graphite: 0.8-1.5 parts, the nano montmorillonite: 0.7-2 parts.

8. The method for preparing the polymer composite material for wind power blade cable according to any one of claims 1-7, characterized in that, Including the following steps: S1. The high molecular substrate epoxy-modified polyether ether ketone 30-42 parts and bisphenol A type epoxy resin 15-18 parts are put into a vacuum drying oven, dried at a temperature of 120-140℃ for 4-6 hours, and the water content is controlled to be ≤0.3%; the reinforcing material continuous glass fiber 18-25 parts is treated by surface degreasing, then dried at a temperature of 80-100℃ for 2-3 hours, the carbon fiber chopped strand 6-10 parts is soaked in a silane coupling agent solution with a concentration of 5% for 30 minutes, then dried at a temperature of 110℃ for 1.5 hours, and the nano silicon nitride 1-3 parts is airflow pulverized to a particle size of ≤500 nm; the polymer modified material hydroxyl-terminated polybutadiene 3-5 parts and fluorocarbon resin 2-4 parts are stored at a constant temperature of 25±3℃ to avoid delamination; S2. The dried high molecular substrate, treated reinforcing material, functional additives, ultraviolet resistant agent 0.5-1 parts, antioxidant 0.8-1.5 parts, silane coupling agent 0.7-1.2 parts, nano titanium dioxide 1-2.8 parts, and auxiliary functional materials magnesium hydroxide 1.5-2.5 parts, aluminum hydroxide 1-2 parts, expanded graphite 0.8-1.5 parts, and nano montmorillonite 0.7-2 parts are put into a high-speed mixer and mixed in three stages: Coarse mixing: rotation speed 300-400 r / min, stirring for 5 min, to eliminate the accumulation of raw materials; Fine mixing: rotation speed 600-800 r / min, stirring for 12 min, adding polymer modified material hydroxyl-terminated polybutadiene 3-5 parts and fluorocarbon resin 2-4 parts; Homogenization: rotation speed 1200-1500 r / min, stirring for 8 min, detected by an online particle size analyzer to ensure that the particle size of the agglomerated particles is ≤10 μm and the mixing uniformity is ≥99%; S3. The performance regulator polyether ether ketone wax 0.5-1 parts, polyimide micro powder 0.4-0.9 parts, and titanium ester coupling agent 0.3-0.9 parts are put into a static mixer with deionized water in a mass ratio of 1:5, the water temperature is controlled at 25-30℃, and the premixed homogeneous solution is stirred for 15 min; S4. The mixed dry powder obtained in step S2 and the liquid performance regulator solution prepared in step S3 are put into a twin-screw extruder in a mass ratio of 100:8-12, the screw rotation speed is 80-120 r / min, and after extrusion, the particles are obtained by water cooling and granulation, and the particle size is 2-4 mm; S5. The composite material particles are put into a vacuum injection molding machine, the injection molding temperature is controlled at 240-260℃, the injection molding pressure is 80-100 MPa, the holding pressure is 60-70 MPa, the holding time is 15-20 s, the mold temperature is 80-100℃, and after molding, the product is naturally cooled to room temperature, and the cooling time is 30-40 min. S6. Post-processing maintenance: after the composite material product is shaped, it is put into a UV aging box, pre-processed for 48 hours under the conditions of UV light intensity 30 W / m2, temperature 60 ℃, humidity 50%; then transferred into a wet heat curing box, cured for 7 days under the conditions of temperature 40 ℃, humidity 90%, the surface state of the product is monitored daily; finally, low-temperature aging treatment is performed, kept at -40 ℃ for 24 hours, naturally warmed to room temperature, and the post-processing is completed; S7. The wind power blade cable polymer composite material prepared in steps S1 to S6 is subjected to performance detection and packaging, and the detection items include tensile strength, bending modulus, fatigue resistance, UV aging resistance, flame resistance, dimensional stability and wet heat resistance.

9. The method for preparing a polymer composite material for wind turbine blade cables according to claim 8, characterized in that, The step S4 stage control extrusion temperature is respectively: feeding section 160-180 ℃, compression section 200-220 ℃, melting section 230-250 ℃, and head section 220-230 ℃.

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