An epoxy resin composite material for insulation of offshore wind turbine equipment and its preparation method

Abstract

This invention relates to an epoxy resin composite material for insulation of offshore wind turbine equipment and its preparation method, belonging to the technical field of insulation materials for offshore wind turbine equipment. The preparation method of the epoxy resin composite material for insulation of offshore wind turbine equipment includes: dispersing nano-MgF2 in an activation liquid after plasma treatment to obtain a MgF2 dispersion; subsequently adding an initiator and styrene to perform a grafting reaction to obtain modified MgF2; dissolving the modified MgF2 in a solvent to obtain a premixed liquid; dispersing the modified epoxy matrix in the premixed liquid; adding a curing agent and an accelerator and stirring evenly; and then degassing, curing, cooling, and demolding to obtain the final product. This epoxy resin composite material for insulation of offshore wind turbine equipment exhibits excellent hydrophobicity and insulation properties, high interfacial bonding strength, and can adapt to the harsh operating environment of offshore wind turbines, including high humidity, high salt spray, and strong vibration. It can be used for core insulation components such as high-voltage busbar insulation support in the nacelle of new energy offshore wind turbines, insulated bushings for hub motors, and insulated seals for submarine cable terminals.

Description

Technical Field

[0001] This invention belongs to the technical field of insulation materials for offshore wind turbine equipment, specifically relating to an epoxy resin composite material for insulation of offshore wind turbine equipment and its preparation method. Background Technology

[0002] With the deepening of the "dual carbon" strategy, offshore wind power has entered a stage of large-scale, deep-sea development. High voltage requirements necessitate high-voltage busbar voltages of 10-35 kV for the nacelle, while long lifespans require a design and maintenance cycle exceeding 25 years. Withstanding the harsh marine environment of high salt spray, high humidity, and strong vibration has become a core technological requirement for offshore wind turbine equipment. The nacelle high-voltage busbar insulation support, hub motor insulation bushing, and submarine cable terminal insulation seals, as key insulation components of offshore wind turbines, bear the dual functions of mechanical load-bearing and electrical isolation. Epoxy resin (EP), with its excellent dielectric properties, mechanical strength, and processability, has become the mainstream matrix material for these core insulation components.

[0003] Offshore wind turbines operate in extreme marine environments for extended periods, with average annual relative humidity exceeding 85% and salt spray concentrations reaching 35 mg / m³. 3 In this harsh environment, the polar groups in the epoxy resin molecular chain easily form hydrogen bonds and chemical adsorption with water molecules and salt spray ions, leading to an abnormally high dielectric constant after moisture absorption, exceeding 30% compared to the dry state. Simultaneously, the dielectric loss increases significantly, with its tanδ value exceeding 0.015, further causing insulation degradation phenomena such as space charge accumulation and a decrease in surface flashover voltage. Modification with nano-inorganic fillers is a core technical approach to improve the marine environmental adaptability of epoxy resins. By constructing a "filler-matrix" interface transition zone, it can both regulate charge transport to improve insulation and block the penetration of moisture and salt spray ions, and its effectiveness has been verified in terrestrial new energy insulation systems. However, directly adding nano-inorganic fillers to epoxy resin still faces three major technical bottlenecks in adapting to offshore wind power: First, the interfacial bonding energy between nano-inorganic fillers and the epoxy resin matrix is ​​low, making them prone to agglomeration and forming microscopic defects, which cannot resist interfacial cracking caused by long-term vibration of the wind turbine; second, the high surface energy of nano-inorganic fillers limits the improvement in hydrophobicity and salt spray resistance, and conductive channels will form on the surface after salt spray immersion, accelerating insulation degradation; third, agglomerates lead to an increase in the density of shallow traps in the interfacial region. The energy level of these shallow traps is below 0.6 eV, and at the same time, they exacerbate the accumulation of space charge, with the accumulated charge density exceeding 0.8 C / m. 3The existing technology cannot meet the insulation safety requirements of offshore wind turbines under high-voltage conditions. Therefore, developing a modification technology and preparation method that can simultaneously solve the problems of dispersion, interfacial bonding, and material "damp heat resistance, salt spray resistance, and vibration resistance" of nano-inorganic fillers, and synergistically improve insulation performance, is of great engineering significance and has broad application prospects for promoting the lifespan of offshore wind turbine insulation components to match the overall turbine operation and maintenance cycle, reducing the maintenance cost of deep-sea and offshore wind power, and ensuring the stable grid connection of offshore wind power. Summary of the Invention

[0004] The first objective of this invention is to provide a method for preparing an epoxy resin composite material for insulation of offshore wind turbine equipment to solve the technical problems of poor dispersibility and poor interfacial bonding of nano-inorganic fillers with the matrix.

[0005] A second objective of this invention is to provide an epoxy resin composite material for insulation of offshore wind turbine equipment.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] A method for preparing an epoxy resin composite material for insulation of offshore wind turbine equipment includes the following steps:

[0008] S1: Nano MgF2 is plasma treated and then dispersed in an activation solution to obtain a MgF2 dispersion. An initiator and styrene are added to the MgF2 dispersion to carry out a grafting reaction to obtain modified MgF2.

[0009] S2: Dissolve modified MgF2 in a solvent to obtain a premixed solution, disperse the modified epoxy group in the premixed solution, then add curing agent and accelerator and stir evenly. After degassing, curing, cooling and demolding, the product is obtained.

[0010] Furthermore, in S1, the nano-MgF2 is dried and then subjected to plasma treatment to obtain pretreated nano-MgF2. The pretreated nano-MgF2 is allowed to stand for 10-15 min and then dispersed in the activation solution. The plasma treatment conditions are: air atmosphere, treatment power of 100-150 W, and treatment time of 8-10 min.

[0011] Furthermore, the activation solution is an ethanol solution of a silane coupling agent; the mass of the silane coupling agent is 15-20% of the mass of the nano-MgF2.

[0012] Furthermore, the initiator is benzoyl peroxide, and the mass of the initiator is 1 to 1.5% of the mass of the styrene; the mass ratio of the nano-MgF2 to the styrene is 1:1.

[0013] Furthermore, the preparation method of the modified MgF2 described in S1 includes: firstly, ultrasonically dispersing the MgF2 dispersion at 55-60 °C and 250-300 W for 20-30 min, then stirring at 550-600 rpm for 30-35 min, finally adding the initiator and styrene, and stirring the reaction at 65-70 °C and 550-600 rpm for 30-35 min to obtain the reaction product, centrifuging the reaction product to collect the precipitate, washing the precipitate with ethanol and drying it to obtain the modified MgF2.

[0014] Furthermore, the solvent in S2 is acetone; the curing agent is methyltetrahydrophthalic anhydride; and the accelerator is 2,4,6-tris(dimethylaminomethyl)phenol.

[0015] Furthermore, the preparation method of the modified epoxy matrix includes: mixing epoxy-terminated polydimethylsiloxane with epoxy resin, ultrasonically treating it at 250-300 W for 5-7 min, and then stirring it at 30-35 ℃ and 500-550 rpm for 30-35 min to obtain the modified MgF2, the mass of which is 1-3% of the total mass of the epoxy resin.

[0016] Furthermore, the mass ratio of the epoxy-terminated polydimethylsiloxane to the epoxy resin is 1:10; the mass ratio of the curing agent to the epoxy resin is 0.85:1; and the mass ratio of the epoxy resin to the accelerator is 100:0.3.

[0017] An epoxy resin composite material for insulation of offshore wind turbine equipment is prepared by the above-described preparation method for epoxy resin composite material for insulation of offshore wind turbine equipment.

[0018] The beneficial effects of this invention are:

[0019] This invention modifies nano-MgF2 through plasma activation-silane coupling-styrene grafting, enabling the modified MgF2 to form a strong interfacial bond with the epoxy resin matrix. EDS testing shows that the proportions of Mg, F, and Si elements in the epoxy resin composite material for insulation of offshore wind turbine equipment with added modified MgF2 are significantly reduced, proving that the polystyrene graft layer and the silane coupling layer together form a complete coating structure. This structure significantly improves the interfacial bonding tightness of the "filler-matrix" interface, which allows the epoxy resin composite material for insulation of offshore wind turbine equipment of this invention to withstand the interfacial stress caused by long-term vibration of offshore wind turbines and avoid cracking.

[0020] The low surface energy of the benzene ring in polystyrene works synergistically with the Si-O-Si skeleton of epoxy-terminated polydimethylsiloxane, thereby increasing the static contact angle of the epoxy resin composite material for insulation of offshore wind turbine equipment from 95.19° to 107.73°, which can effectively resist the corrosion of high humidity and high salt spray environment at sea.

[0021] The epoxy resin composite material prepared by this invention for insulation of offshore wind turbine equipment exhibits excellent hydrophobicity and insulation properties, high interfacial bonding strength, and can withstand the harsh operating environment of offshore wind turbines characterized by high humidity, high salt spray, and strong vibration. It can be used for core insulation components such as high-voltage busbar insulation supports in the nacelle of new energy offshore wind turbines, insulated bushings for hub motors, and insulated seals for submarine cable terminals. The raw materials used in this invention are readily available, and ultrasonic dispersion, step-curing, and vacuum degassing can be achieved using existing equipment without special stringent conditions. Production costs are controllable, making it suitable for large-scale production. Attached Figure Description

[0022] Figure 1 A flowchart illustrating the preparation process of epoxy resin composite materials used for insulation of offshore wind turbine equipment;

[0023] Figure 2 Infrared spectra of the epoxy resin composite materials in Examples 1-2 and Comparative Examples 1-3;

[0024] Figure 3 The images show the SEM and EDS images of the epoxy resin composites of Example 2 and Comparative Example 3, where a is the SEM and EDS image of the epoxy resin composite of Comparative Example 3 and b is the SEM and EDS image of the epoxy resin composite of Example 2.

[0025] Figure 4 The dielectric spectra are shown in Examples 1-2 and Comparative Example 3, where a is the dielectric spectrum and b is the dielectric loss spectrum.

[0026] Figure 5 The diagrams show the surface potential and trap energy levels of the epoxy resin composite materials in Examples 1-2 and Comparative Examples 1-3, where a is the surface potential diagram and b is the trap energy level diagram.

[0027] Figure 6 The static water contact angle diagrams are shown for the epoxy resin composite materials in Examples 1-2 and Comparative Examples 1-3. Detailed Implementation

[0028] The present invention will be further described below with reference to the embodiments and accompanying drawings.

[0029] The nano-MgF2 used in this invention has a particle size of 30 nm and a purity of ≥99.9%.

[0030] The epoxy-terminated polydimethylsiloxane was purchased from Silicone Oil Home (Shenzhen) Chemical Products Center.

[0031] Example 1

[0032] The preparation method of the epoxy resin composite material for insulation of offshore wind turbine equipment in Example 1 includes the following steps:

[0033] S1: Dissolve 0.126 g of silane coupling agent KH-570 in 5.5 mL of 90% ethanol, stir magnetically at 200 rpm for 10 min, and let stand at 25 °C for 20 min to obtain an activation solution. Dry 0.84 g of nano-MgF2 under vacuum at 100 °C for 2 h. Immediately after drying, spread it evenly on a quartz dish and treat it with plasma at 100 W in air for 10 min to introduce hydroxyl active sites, obtaining pretreated nano-MgF2. After waiting for 10 min, add the pretreated nano-MgF2 to the activation solution to avoid deactivation of hydroxyl active sites. Then, ultrasonically disperse at 55 °C and 300 W for 30 min, and stir at 600 rpm for 30 min to obtain a MgF2 dispersion. 0.011 g of benzoyl peroxide (BPO) and 0.84 g of styrene (St) were mixed and then added to a MgF2 dispersion. The mixture was stirred at 70 °C and 600 rpm for 30 min to allow styrene to undergo free radical copolymerization in nano-MgF2 to obtain the reaction product. The reaction product was centrifuged at 8000 rpm for 10 min, and the precipitate was collected. The precipitate was washed three times with anhydrous ethanol and dried under vacuum at 60 °C for 24 h to obtain modified MgF2, which was named PS-g-MgF2.

[0034] S2: Mix 24 g of epoxy resin E-51 and 2.4 g of epoxy-terminated polydimethylsiloxane, ultrasonically disperse at 300 W for 5 min, and then stir at 30 ℃ and 500 rpm for 30 min to obtain the modified epoxy matrix.

[0035] S3: A premix was prepared by mixing 0.24 g of PS-g-MgF2 with 12 mL of acetone. The premix was then mixed with 26.4 g of the modified epoxy matrix and pre-dispersed by stirring at 35 °C and 600 rpm for 10 min, followed by ultrasonic dispersion at 300 W for 30 min. Then, 20.4 g of methyltetrahydrophthalic anhydride (MeTHPA) was added, and the mixture was stirred at 500 rpm for 30 min. Next, 0.072 g of 2,4,6-tris(dimethylaminomethyl)phenol (DMP-30) was added, and the mixture was stirred at 500 rpm for another 30 min to obtain a final mixture. The mixture was then placed in a vacuum dryer and degassed under vacuum at -0.095 MPa and 50 °C for 40 min to remove air bubbles.

[0036] S4: Coat the inner wall of the mold with a fluorocarbon release agent, vacuum dry at 130 ℃ for 2 h, cool to room temperature, preheat to 90 ℃, and then inject the degassed mixture into the mold. Use a flat vulcanizing machine for stepped curing: cure at 90 ℃ for 1 h, then increase the temperature to 120 ℃ and cure for 3 h. Turn off the heat source, maintain pressure, and cool down at a rate of 2 ℃ / min. Demold when the temperature drops to 60 ℃. The epoxy resin composite material used for insulation of offshore wind turbine equipment in Example 1 is named G-MgF2 1%.

[0037] Example 2

[0038] The preparation method of the epoxy resin composite material for insulation of offshore wind turbine equipment in Example 2 includes the following steps:

[0039] S1: Dissolve 0.38 g of silane coupling agent KH-570 in 16.5 mL of 90% ethanol (v / v), stir magnetically at 200 rpm for 10 min, and let stand at 25 °C for 20 min to obtain an activation solution. Dry 2.52 g of nano-MgF2 under vacuum at 100 °C for 2 h. Immediately after drying, spread it evenly on a quartz dish and plasma-treat it in air at 100 W for 10 min to obtain pretreated nano-MgF2. After waiting for 10 min, add the pretreated nano-MgF2 to the activation solution and ultrasonically disperse it at 55 °C and 300 W for 30 min, followed by stirring at 600 rpm for 30 min to obtain a MgF2 dispersion. 0.033 g of BPO and 2.52 g of St were mixed and then added to a MgF2 dispersion. The mixture was stirred at 70 °C and 600 rpm for 30 min to obtain the reaction product. The reaction product was centrifuged at 8000 rpm for 10 min, and the precipitate was collected. The precipitate was washed three times with anhydrous ethanol and dried under vacuum at 60 °C for 24 h to obtain PS-g-MgF2.

[0040] S2: Mix 24 g of epoxy resin E-51 and 2.4 g of epoxy-terminated polydimethylsiloxane, ultrasonically disperse at 300 W for 5 min, and then stir at 30 ℃ and 500 rpm for 30 min to obtain the modified epoxy matrix.

[0041] S3: A premix was prepared by mixing 0.72 g of PS-g-MgF2 with 12 mL of acetone. This premix was then mixed with 26.4 g of the modified epoxy matrix and pre-dispersed by stirring at 35 °C and 600 rpm for 10 min, followed by ultrasonic dispersion at 300 W for 30 min. 20.40 g of MeTHPA was added to the reaction system, and the mixture was stirred at 500 rpm for 30 min. Then, 0.072 g of DMP-30 was added, and the mixture was stirred at 500 rpm for another 30 min to obtain a final mixture. The mixture was then placed in a vacuum dryer and degassed under vacuum at -0.095 MPa and 50 °C for 40 min.

[0042] S4: Coat the inner wall of the mold with a fluorocarbon release agent, vacuum dry at 130 ℃ for 2 h, cool to room temperature, preheat to 90 ℃, and inject the degassed mixture into the mold. Use a flat vulcanizing machine for stepped curing: cure at 90 ℃ for 1 h, then increase the temperature to 120 ℃ and cure for 3 h. Turn off the heat source, maintain pressure, and cool down at a rate of 2 ℃ / min. Demold when the temperature drops to 60 ℃. The epoxy resin composite material used for insulation of offshore wind turbine equipment in Example 2 is named G-MgF2 3%.

[0043] Comparative Example 1

[0044] The preparation method of the epoxy resin composite material of Comparative Example 1 includes the following steps:

[0045] S1: Stir 24 g of epoxy resin E-51 at 500 rpm for 10 min, add 20.4 g of MeTHPA, stir at 500 rpm for 30 min, add 0.072 g of DMP-30, and continue stirring at 500 rpm for 30 min to obtain a homogeneous mixture. Place the mixture in a vacuum dryer and degas at -0.095 MPa and 50 ℃ for 40 min.

[0046] S2: Coat the inner wall of the mold with a fluorocarbon release agent, vacuum dry at 130 ℃ for 2 h, cool to room temperature, preheat to 90 ℃, and inject the degassed mixture into the mold. Use a flat vulcanizing machine for stepped curing: cure at 90 ℃ for 1 h, then increase the temperature to 120 ℃ and cure for 3 h. Turn off the heat source, maintain pressure, and cool down at a rate of 2 ℃ / min. Demold when the temperature drops to 60 ℃. The epoxy resin composite material of Comparative Example 1 is named Pure EP.

[0047] Comparative Example 2

[0048] The preparation method of the epoxy resin composite material of Comparative Example 2 includes the following steps:

[0049] S1: Mix 24 g of epoxy resin E-51 and 2.4 g of epoxy-terminated polydimethylsiloxane, sonicate at 300 W for 5 min for initial dispersion, and then stir at 30 ℃ and 500 rpm for 30 min to form a uniform modified epoxy body.

[0050] S2: Add 20.4 g of MeTHPA to the modified epoxy matrix, stir at 500 rpm for 30 min, add 0.072 g of DMP-30, and continue stirring at 500 rpm for 30 min to obtain a homogeneous mixture. Place the mixture in a vacuum dryer and degas at -0.095 MPa and 50 ℃ for 40 min.

[0051] S3: Coat the inner wall of the mold with a fluorocarbon release agent, vacuum dry at 130 ℃ for 2 h, cool to room temperature, preheat to 90 ℃, and inject the degassed mixture into the mold. Use a flat vulcanizing machine for stepped curing: cure at 90 ℃ for 1 h, then increase the temperature to 120 ℃ and cure for 3 h. Turn off the heat source, maintain pressure, and cool down at a rate of 2 ℃ / min. Demold when the temperature drops to 60 ℃. The epoxy resin composite material of Comparative Example 2 is named EP / PDMS.

[0052] Comparative Example 3

[0053] The preparation method of the epoxy resin composite material of Comparative Example 3 includes the following steps:

[0054] S1: Mix 24 g of epoxy resin E-51 and 2.4 g of epoxy-terminated polydimethylsiloxane, sonicate at 300 W for 5 min for initial dispersion, and then stir at 30 ℃ and 500 rpm for 30 min to form a uniform modified epoxy body.

[0055] S2: A premix was prepared by mixing 0.72 g of nano-MgF2 with 12 mL of acetone. The premix was then mixed with 26.4 g of modified epoxy matrix and pre-dispersed by stirring at 35 ℃ and 600 rpm for 10 min. The mixture was then ultrasonically dispersed at 300 W for 30 min to break up particle agglomerations, resulting in the reaction system. 20.4 g of MeTHPA was added to the reaction system, and the mixture was stirred at 500 rpm for 30 min. Then, 0.072 g of DMP-30 was added, and the mixture was stirred at 500 rpm for another 30 min to achieve homogeneity. The mixture was then placed in a vacuum dryer and degassed under vacuum at -0.095 MPa and 50 ℃ for 40 min.

[0056] S3: Coat the inner wall of the mold with a fluorocarbon release agent, vacuum dry at 130 ℃ for 2 h, cool to room temperature, preheat to 90 ℃, and inject the degassed mixture into the mold. Use a flat vulcanizing machine for stepped curing: cure at 90 ℃ for 1 h, then increase the temperature to 120 ℃ and cure for 3 h. Turn off the heat source, maintain pressure, and cool down at a rate of 2 ℃ / min. Demold when the temperature drops to 60 ℃. The epoxy resin composite material of Comparative Example 3 is named P-MgF2 3%.

[0057] from Figure 2 It can be seen that the epoxy resin composite materials of Examples 1-2 have a thickness of 1600-1500 cm. -1 The presence of a monosubstituted benzene ring characteristic peak and the detection of a Si-O-Si characteristic peak confirms styrene grafting and silane introduction. Figure 3 It can be seen that the epoxy resin composite material with unmodified MgF2 exhibits obvious agglomeration, while the epoxy resin composite material with modified MgF2 is uniformly dispersed and has no obvious defects. EDS data shows that the weight percentages of Mg, F, and Si elements in the epoxy resin composite material of Example 2 decreased to 0.14%, 0.78%, and 1.19%, respectively, which is significantly lower than that in the epoxy resin composite material of Comparative Example 3. The core reason is that the polystyrene and silane coupling agent form a continuous and dense double-layer coating structure, which produces a physical shielding effect on the characteristic elements. The characteristic X-ray penetration depth of the EDS detector is limited. When the polystyrene graft layer and the silane coupling layer form a complete coating, the Mg and F elements in the MgF2 core and the Si element in the silane coupling layer are shielded by the outer polystyrene graft layer, resulting in a significant reduction in the intensity of the characteristic X-ray signals of Mg, F, and Si received by the EDS detector. This is reflected in the quantitative results as a simultaneous decrease in the weight percentage and atomic percentage of Mg, F, and Si elements. Figure 4 The dielectric constant of the epoxy resin composite material in Example 2 was increased by 9% compared to that in Comparative Example 3. The dielectric constant of the epoxy resin composite material in Example 2 was significantly higher than that in Comparative Example 3, especially in the low-frequency region. This phenomenon can be attributed to the combined effect of two types of polarization: firstly, the huge dielectric difference between nano-MgF2 and the epoxy matrix induces strong interfacial polarization; secondly, the modification by plasma and KH570 grafted styrene introduced a large number of interfacial functional groups and molecular chain segments between nano-MgF2 and the epoxy matrix, forming a wider and more complex interfacial region. Figure 4The reduced dielectric loss of the epoxy resin composite material in Example 2 (b) is due to the uniform dispersion of PS-g-MgF2 in the epoxy matrix and the tight interfacial bonding, which greatly inhibits the formation of ion migration channels, thereby reducing dielectric loss. These modified MgF2 particles act as deep-level charge traps, limiting the long-range migration of charge carriers through the Coulomb blockade effect, transforming ohmic conduction into repressive hopping conduction, thus significantly reducing the conductivity loss caused by free charge migration. This allows the epoxy resin composite material used for insulation of offshore wind turbine equipment to achieve both high dielectric constant and excellent low-loss insulation performance. Figure 5 Test results show that the surface potential decay rate of the epoxy resin composite material used for insulation of offshore wind turbine equipment in Example 2 is significantly reduced. Figure 5 b. It can be observed that the density of deep traps inside the epoxy resin composite material for insulating the offshore wind turbine equipment in Example 2 is increased. These deep traps can effectively capture free charges and inhibit their migration and accumulation, thereby alleviating the problem of electric field distortion caused by space charge from the root. Figure 5 The slower degradation of the epoxy resin composite material used for insulation of offshore wind turbine equipment in Example 2 directly proves that the modified MgF2 introduced a large number of deep-level traps. After the charge is trapped in these traps, higher energy is required to escape, leading to a reduced dissipation rate. This is consistent with... Figure 5 The results of the trap energy level distribution of b corroborate each other. Figure 6 In this study, the static water contact angle of the modified epoxy resin composite material used for insulating offshore wind turbine equipment increased from 95.19° to 107.73°, successfully achieving a stable hydrophobic state. This is because the Si-O-Si segments in the epoxy-terminated polydimethylsiloxane migrated to the surface of the epoxy resin composite material, reducing the surface energy. At the same time, the polystyrene shell further synergistically constructed a micro-nano hydrophobic structure, and the two worked together to optimize the hydrophobicity.

[0058] Other embodiments of this disclosure will readily occur to those skilled in the art upon consideration of the specification and practice of the disclosure herein. This disclosure is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this disclosure are indicated by the claims.

[0059] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. The scope of patent protection of the present invention shall be determined by the claims. Similarly, any equivalent structural changes made based on the content of the present invention's specification shall also be included within the scope of protection of the present invention.

Claims

1. A method for preparing an epoxy resin composite material for insulation of offshore wind turbine equipment, characterized in that, Includes the following steps: S1: Nano-MgF2 is plasma-treated and then dispersed in an activation solution to obtain a MgF2 dispersion. An initiator and styrene are added to the MgF2 dispersion to carry out a grafting reaction to obtain modified MgF2. The activation solution is an ethanol solution of a silane coupling agent. The mass of the silane coupling agent is 15-20% of the mass of the nano-MgF2. S2: Dissolve modified MgF2 in a solvent to obtain a premixed solution, disperse the modified epoxy matrix in the premixed solution, then add curing agent and accelerator and stir evenly. After degassing, curing, cooling and demolding, the product is obtained. The method for preparing the modified epoxy matrix includes: mixing epoxy-terminated polydimethylsiloxane with epoxy resin, ultrasonically treating it at 250-300 W for 5-7 min, and then stirring it at 30-35 ℃ and 500-550 rpm for 30-35 min to obtain the modified MgF2, the mass of which is 1-3% of the total mass of the epoxy resin.

2. The method for preparing the epoxy resin composite material for insulation of offshore wind turbine equipment according to claim 1, characterized in that, In S1, the nano-MgF2 is dried and then subjected to plasma treatment to obtain pretreated nano-MgF2. The pretreated nano-MgF2 is allowed to stand for 10-15 min and then dispersed in the activation solution. The plasma treatment conditions are: air atmosphere, treatment power of 100-150 W, and treatment time of 8-10 min.

3. The method for preparing the epoxy resin composite material for insulation of offshore wind turbine equipment according to claim 1, characterized in that, The initiator is benzoyl peroxide, and the mass of the initiator is 1 to 1.5% of the mass of styrene; the mass ratio of nano-MgF2 to styrene is 1:

1.

4. The method for preparing the epoxy resin composite material for insulation of offshore wind turbine equipment according to claim 1, characterized in that, The preparation method of the modified MgF2 described in S1 includes: firstly, ultrasonically dispersing the MgF2 dispersion at 55-60 °C and 250-300 W for 20-30 min, then stirring at 550-600 rpm for 30-35 min, finally adding the initiator and styrene, and stirring the reaction at 65-70 °C and 550-600 rpm for 30-35 min to obtain the reaction product, centrifuging the reaction product to collect the precipitate, washing the precipitate with ethanol and drying it to obtain the modified MgF2.

5. The method for preparing the epoxy resin composite material for insulation of offshore wind turbine equipment according to claim 1, characterized in that, The solvent in S2 is acetone; the curing agent is methyltetrahydrophthalic anhydride; and the accelerator is 2,4,6-tris(dimethylaminomethyl)phenol.

6. The method for preparing the epoxy resin composite material for insulation of offshore wind turbine equipment according to claim 1, characterized in that, The mass ratio of the epoxy-terminated polydimethylsiloxane to the epoxy resin is 1:10; the mass ratio of the curing agent to the epoxy resin is 0.85:1; and the mass ratio of the epoxy resin to the accelerator is 100:0.

3.

7. An epoxy resin composite material for insulation of offshore wind turbine equipment, characterized in that, The epoxy resin composite material for insulation of offshore wind turbine equipment is prepared by the method described in any one of claims 1 to 6.

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