Plasma-modified epoxy resin wind turbine blade coating and its preparation method

Abstract

This invention discloses a plasma-fluorinated modified epoxy resin wind turbine blade coating and its preparation method, applicable to wind turbine blades. The coating is formed by curing an epoxy resin matrix composition and modified fillers. The modified fillers are nano-zinc oxide and short-cut basalt fibers that have been surface-modified with a silane coupling agent and then fluorinated by dielectric barrier discharge plasma treatment, with a mass ratio of 1:1. The total mass of the fillers accounts for 1% to 9% of the total coating mass. In the preparation process, the fillers are first coupled and modified with KH560, then plasma fluorination is performed using CF4 as the working gas. The resulting synergistically modified fillers are dispersed in the epoxy resin, and a curing agent, toughening agent, and accelerator are added. After degassing and gradient curing, the coating is formed. With a filler content of 5 wt%, the coating tensile strength increases by 21.94%, and the breakdown field strength increases by 48.06%, exhibiting excellent overall performance and suitable for surface protection of wind turbine blades.

Description

Technical Field

[0001] This invention belongs to the field of new materials and wind power generation technology, specifically relating to plasma fluorinated modified epoxy resin wind turbine blade coating, a method for preparing the plasma fluorinated modified epoxy resin wind turbine blade coating, and a wind turbine blade coated with the plasma fluorinated modified epoxy resin wind turbine blade coating. Background Technology

[0002] Wind power generation, as an important component of clean energy, has seen continuous growth in installed capacity. Wind turbine blades, as the core component of wind turbines for capturing wind energy, are exposed to harsh natural environments for extended periods, enduring complex loads such as gravity, aerodynamic loads, and centrifugal forces. This makes them prone to surface cracks and delamination between fibers and resin, which can damage the blade's surface insulation structure and lead to insulation failure under lightning strikes. Epoxy resin, due to its good moldability and strong adhesion, is often used as the base material for protective coatings on wind turbine blades. However, pure epoxy resin suffers from insufficient toughness, poor impact resistance, and unsatisfactory dielectric properties, making it difficult to simultaneously meet the dual requirements of mechanical and electrical insulation performance for wind turbine blades.

[0003] To improve the overall performance of epoxy resins, the industry commonly uses the addition of inorganic micro / nano fillers. However, there is a critical threshold for the amount of filler added; exceeding this threshold can lead to filler agglomeration, resulting in decreased interfacial bonding strength and ultimately deteriorating material properties. Silane coupling agents are a conventional method for improving filler dispersibility. By constructing chemical bridges between inorganic fillers and organic resins, they can improve the interfacial compatibility of the two phases to some extent. However, the improvement in the overall performance of composite materials by modifying with a single silane coupling agent is limited, especially in terms of its effect on optimizing electrical insulation properties.

[0004] Low-temperature plasma fluorination modification technology can introduce fluorine-containing functional groups onto the material surface. Utilizing the high bond energy and strong hydrophobicity of the C-F bond, it reduces the surface energy of the filler, inhibits particle aggregation, and simultaneously optimizes the interfacial charge distribution, thereby improving the material's insulation performance. However, most existing technologies employ either coupling agent modification or plasma fluorination modification alone, using these two processes independently without a reasonable synergistic combination. A search of existing patents and journal articles reveals the following significant shortcomings in current modification schemes: (1) Although single coupling agent modification can improve the dispersibility of filler, it cannot effectively control the interfacial charge behavior and the insulation performance is limited; although single plasma fluorination modification can optimize the surface electrical properties, it cannot build a stable chemical bond layer between inorganic filler and organic resin, resulting in weak interfacial bonding and easily damaged mechanical properties.

[0005] (2) In the prior art, there are occasional attempts to combine the two processes, but the processing order is mostly fluorination first and then coupling modification, which results in the fluorine functional groups being covered by the subsequent coupling agent, the modification effect is limited, and it is difficult to form an effective synergistic gain.

[0006] (3) When conventional nanofillers and chopped fiber fillers are simply blended, heterogeneous agglomeration is likely to occur due to differences in morphology and surface properties, and it is always impossible to achieve simultaneous improvement in mechanical properties and electrical insulation properties.

[0007] Therefore, a common technical bias exists in this field, suggesting that coupling modification and plasma fluorination processes are difficult to synergize effectively, and that step-by-step combination cannot produce significant performance gains. How to simultaneously improve the mechanical strength and electrical insulation properties of epoxy resin-based coatings while ensuring good filler dispersibility has become a pressing technical challenge in this field. Summary of the Invention

[0008] The primary objective of this invention is to provide a plasma-fluorinated modified epoxy resin wind turbine blade coating, which solves the technical problem that inorganic fillers in existing epoxy resin-based coatings tend to agglomerate and have many interface defects, making it difficult to synergistically improve mechanical strength and electrical insulation performance.

[0009] The second objective of this invention is to provide a method for preparing plasma fluorination modified epoxy resin wind turbine blade coatings, which solves the technical problem that existing coupling agent modification processes and plasma fluorination processes are difficult to effectively coordinate, and improper combination order leads to a significant reduction in modification effect.

[0010] The third objective of this invention is to provide wind turbine blades that address the technical problem that existing wind turbine blade surface coatings are prone to cracking, interface debonding, and insulation failure under complex loads and lightning strikes, making it difficult to meet the requirements for long-term reliable operation.

[0011] The first technical solution adopted in this invention is a plasma fluorinated modified epoxy resin wind turbine blade coating, wherein the coating is formed by curing an epoxy resin matrix composition and a modified filler uniformly dispersed therein. The epoxy resin matrix composition comprises epoxy resin, curing agent, toughening agent and accelerator; The modified filler consists of nano zinc oxide and short-cut basalt fibers that have been surface modified with silane coupling agent and then fluorinated by dielectric barrier discharge plasma, with a mass ratio of nano zinc oxide to short-cut basalt fibers of 1:1. The total mass of modified fillers accounts for 1% to 9% of the total mass of the coating.

[0012] The first technical solution of this invention is further characterized by: The total mass of the modified filler accounts for 5% of the total mass of the coating.

[0013] The silane coupling agent is KH560, and the working gas for dielectric barrier discharge plasma fluorination treatment is CF4; or the silane coupling agent is KH550 or KH570, and the working gas is SF6 or C4F8.

[0014] Based on 100 parts by weight of epoxy resin, the curing agent is 15-25 parts by weight, the toughening agent is 3-8 parts by weight, and the accelerator is 0.5-2 parts by weight.

[0015] The second technical solution adopted in this invention is a method for preparing plasma-fluorinated modified epoxy resin wind turbine blade coating, comprising the following steps: Step 1: Mix nano zinc oxide and chopped basalt fibers at a mass ratio of 1:1, add silane coupling agent and deionized water to carry out surface modification reaction, and obtain coupling modified filler after drying; Step 2: Place the coupling modified filler in a dielectric barrier discharge plasma reaction chamber and perform plasma fluorination treatment using fluorine-containing gas as the working gas to obtain the synergistic modified filler. Step 3: Disperse the synergistic modified filler in epoxy resin, then add curing agent, toughening agent and accelerator, mix evenly, and then degas and gradient cure to form a composite coating on the surface of wind turbine blades.

[0016] The second technical solution of the present invention is further characterized by: In step 1, the silane coupling agent is KH560, and the addition amount is 10g of KH560 per 100g of filler. The amount of deionized water added is 5g per 100g of filler. The modification reaction conditions are: 50℃ constant temperature water bath, mechanical stirring and ultrasonic dispersion treatment for 20min~40min, and then drying at 80℃ until dry.

[0017] In step 2, the fluorine-containing gas is CF4; the dielectric barrier discharge plasma treatment parameters are: voltage 2.0kV~3.0kV, frequency 8kHz~10kHz, cavity gas pressure below 10Pa, and treatment time 5min~15min.

[0018] In step 3, the gradient curing process involves holding the product at 100℃, 110℃, 120℃, 140℃, and 150℃ for 1 hour each.

[0019] The total amount of synergistic modified fillers added accounts for 5% of the total mass of the coating.

[0020] The third technical solution adopted in this invention is a wind turbine blade, the surface of which is coated with a plasma fluorinated modified epoxy resin wind turbine blade coating, or the above-mentioned preparation method is used to form a plasma fluorinated modified epoxy resin wind turbine blade coating on its surface.

[0021] The beneficial effects of this invention are: This invention achieves significant beneficial effects through a positive synergistic modification process of "silane coupling grafting followed by plasma fluorination modification," combined with a precise 1:1 blend of nano-zinc oxide and short-cut basalt fibers. With a filler content of 5 wt%, the composite coating exhibits a 21.94% increase in tensile strength, a 32.62% increase in interfacial shear strength, a 41.62% increase in volume resistivity, a 55.91% increase in partial discharge initiation voltage, and a 48.06% increase in AC breakdown field strength compared to pure epoxy resin. Simultaneously, the relative permittivity decreases by 11.44%, and the dielectric loss factor decreases by 41.28%, achieving a substantial synergistic improvement in both mechanical and electrical insulation properties. This synergistic effect far surpasses the simple superposition of single coupling modification or single fluorination modification, overcoming the technical prejudice that the two processes are difficult to effectively synergize. Furthermore, the preparation process of this invention is compatible with existing DBD plasma equipment and epoxy resin coating production lines, requiring no additional large-scale equipment. It boasts good process stability and is easy to mass-produce industrially, providing a protective coating solution for wind turbine blades that combines high mechanical strength, excellent insulation, and good processability. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the fluorination process in the preparation method of the plasma fluorination modified epoxy resin wind turbine blade coating of the present invention. Figure 2 The tensile strength variation curves of the composite coating of the present invention under different filler contents are shown. Figure 3 The graph shows the breakdown field strength variation of the composite coating of the present invention under different filler contents. Detailed Implementation

[0023] This invention discloses a plasma-fluorinated modified epoxy resin wind turbine blade coating, its preparation method, and its application in wind turbine blades. The coating is formed by curing an epoxy resin matrix composition and a uniformly dispersed modified filler therein. The epoxy resin matrix composition includes epoxy resin, a curing agent, a toughening agent, and an accelerator. The modified filler is surface-modified with a silane coupling agent followed by dielectric barrier discharge plasma fluorination treatment (e.g.,...). Figure 1The coating consists of nano-zinc oxide and chopped basalt fibers (as shown), with a mass ratio of nano-zinc oxide to chopped basalt fibers of 1:1. The total mass of the modified filler accounts for 1% to 9% (preferably 5%) of the total mass of the coating. The preferred silane coupling agent is KH560, and the preferred working gas for plasma fluorination is CF4, although KH550 / KH570 and SF6 / C4F8 can also be used. Based on 100 parts by mass of epoxy resin, the curing agent comprises 15 to 25 parts by mass, the toughening agent comprises 3 to 8 parts by mass, and the accelerator comprises 0.5 to 2 parts by mass. The preparation method of the coating includes: first, mixing nano-zinc oxide and chopped basalt fibers in a 1:1 ratio, adding silane coupling agent and deionized water to carry out surface modification reaction, and drying to obtain coupling modified filler; then placing the coupling modified filler in a dielectric barrier discharge plasma reaction chamber and treating it with fluorine-containing gas (preferably CF4) under the conditions of voltage 2.0-3.0kV, frequency 8-10kHz, and pressure below 10Pa for 5-15 minutes to obtain synergistic modified filler; then dispersing the synergistic modified filler in epoxy resin, adding curing agent, toughening agent and accelerator, mixing evenly, and then degassing and gradient curing (holding at 100℃, 110℃, 120℃, 140℃ and 150℃ for 1 hour each) to form a composite coating on the surface of the wind turbine blade. In the coupling modification step, the amount of KH560 added is 10g per 100g of filler, and the amount of deionized water added is 5g per 100g of filler. The modification reaction conditions are a constant temperature water bath at 50℃, mechanical stirring combined with ultrasonic dispersion for 20-40min, and then drying at 80℃ until dry. The total amount of synergistically modified filler added is preferably 5% of the total mass of the coating. This invention overcomes the technical challenges of filler agglomeration, weak interfacial bonding, and difficulty in synergistically improving mechanical and insulation properties through a positive synergistic modification process of "coupling first, then fluorination," combined with a precise 1:1 blend of nano-ZnO and short-cut basalt fiber. It achieves significant beneficial effects: with a filler content of 5 wt%, the tensile strength is increased by 21.94% compared to pure epoxy resin, the interfacial shear strength by 32.62%, the volume resistivity by 41.62%, the partial discharge initiation voltage by 55.91%, and the AC breakdown field strength by 48.06%. Simultaneously, the relative permittivity is reduced by 11.44%, and the dielectric loss factor by 41.28%. The overall performance far exceeds the simple superposition of single modification processes and can be widely applied to the surface protection of wind turbine blades.

[0024] Example 1 (1% filler content, 5 min plasma treatment, 15 parts curing agent) Target filler content: 1%; Matrix formulation: 100g E51 epoxy resin, 15g MTHPA curing agent, 3g toughening agent DH410, 0.5g DMP-30 accelerator; Total mass of the matrix: 100 + 15 + 3 + 0.5 = 118.5 g; Total required mass of packing material: m = (1% / 99%) × 118.5 = 1.197g ≈ 1.20g; Of which: 0.60g of nano-ZnO and 0.60g of short-cut basalt fiber; Step 1: Packing coupling modification treatment 1.1 Weigh 0.60g of nano ZnO (50nm particle size) and 0.60g of short-cut basalt fiber (400μm length), mix them and dry them in an 80℃ constant temperature drying oven for 2h.

[0025] 1.2 Place the dried mixed filler in a container, add 15 mL of anhydrous ethanol to wet it, and treat it for 20 min under constant temperature water bath at 50℃ with mechanical stirring at 4500 r / min and ultrasonic dispersion (power 200 W).

[0026] 1.3 Add 0.12g KH560 silane coupling agent (10% of the filler mass) and 0.06g deionized water (5% of the filler mass) to the system and continue stirring for 40min.

[0027] 1.4 Transfer the mixture into an 80℃ constant temperature forced-air drying oven and dry for 24 hours.

[0028] 1.5 The dried block material was ground into a uniform powder to obtain KH560 coupling modified composite filler.

[0029] Step 2: DBD plasma fluorination modification treatment of the packing material 2.1 Check the sealing of the DBD plasma reaction chamber. After evacuation, confirm that there is no leakage and clean the electrodes.

[0030] 2.2 Place the quartz glass plate between the two electrode plates, spread the coupling modified filler thinly on the surface of the quartz plate (thickness ≤ 0.3 mm), and seal the cavity.

[0031] 2.3 Evacuate the gas until the pressure is below 10 Pa, then introduce CF4 gas to replace it and stabilize the pressure.

[0032] 2.4 Start the plasma generator, set the voltage to 2.0kV and the frequency to 8kHz, and continue the fluorination treatment for 5 minutes.

[0033] 2.5 Turn off the power, vent the gas, remove the modified filler and seal it for storage.

[0034] Step 3: Preparation of epoxy resin composite coating samples 3.1 Weigh 1.20g of the above-mentioned synergistic modified composite filler.

[0035] 3.2 Take 100g of E51 epoxy resin, add filler, and disperse it in a constant temperature water bath at 50℃ with mechanical stirring at 4500r / min and ultrasonic dispersion for 20min.

[0036] 3.3 Add 15g of curing agent MTHPA, 3g of toughening agent DH410, and 0.5g of accelerator DMP-30 in sequence, and continue stirring for 40 minutes.

[0037] 3.4 Vacuum degas the mixed slurry for 20 minutes; clean the mold, spray with release agent, and preheat to 80℃.

[0038] 3.5 Inject into the mold and cure in a gradient: hold at 100℃, 110℃, 120℃, 140℃, and 150℃ for 1 hour each.

[0039] 3.6 Allow the sample to cool naturally before demolding to obtain the final sample.

[0040] Example 2 (5% filler content, 10 min plasma treatment, 20 parts curing agent) Target filler content: 5%; Matrix formulation: E51 100g, curing agent 20g, toughening agent 5g, accelerator 1.0g; Total mass of the matrix: 100 + 20 + 5 + 1 = 126.0 g; Total required mass of packing material: m = (5% / 95%) × 126.0 = 6.632g ≈ 6.63g; Of which: 3.315g of nano ZnO and 3.315g of short-cut basalt fiber; Step 1: Packing coupling modification treatment 1.1 Weigh 3.315g of nano ZnO and 3.315g of short-cut basalt fiber, and dry them.

[0041] 1.2 Add 50 mL of anhydrous ethanol, incubate in a 50°C water bath, stir at 4500 rpm and sonicate for 20 min.

[0042] 1.3 Add 0.663g of KH560 (10% of the total mass of the packing material) and 0.3315g of deionized water (5%), and continue stirring for 40 minutes.

[0043] 1. Dry at 480℃ for 24 hours, then grind.

[0044] Step 2: DBD plasma fluorination modification treatment of the packing material 2.1 Same as steps 2.1-2.3 in Example 1.

[0045] 2.2 Set the voltage to 2.5kV, the frequency to 9kHz, and the processing time to 10min.

[0046] 2.3 The rest is the same as in Example 1.

[0047] Step 3: Preparation of epoxy resin composite coating samples 3.1 Weigh 6.63g of the synergistic modified composite filler.

[0048] 3.2 Add to 100g of E51 resin and disperse for 20min.

[0049] 3.3 Add 20g of curing agent, 5g of toughening agent and 1.0g of accelerator in sequence, and stir for 40 minutes.

[0050] 3.4 Degassing, molding, and gradient curing (conditions are the same as in Example 1).

[0051] 3.5 Cooling and demolding.

[0052] Example 3 (9% filler content, plasma treatment for 15 min, 25 parts curing agent) Target filler content: 9%; Matrix formulation: E51 100g, curing agent 25g, toughening agent 8g, accelerator 2.0g; Total mass of the matrix: 100 + 25 + 8 + 2 = 135.0 g; Total required mass of packing material: m = (9% / 91%) × 135.0 = 13.352g ≈ 13.35g; Of which: 6.675g of nano ZnO and 6.675g of short-cut basalt fiber; Step 1: Packing coupling modification treatment 1.1 Weigh 6.675g of nano ZnO and 6.675g of short-cut basalt fiber, and dry them.

[0053] 1.2 Add 80 mL of anhydrous ethanol, incubate in a 50°C water bath, stir at 4500 rpm and sonicate for 40 min.

[0054] 1.3 Add 1.335g (10%) of KH560 and 0.6675g (5%) of deionized water, and stir for 40 minutes.

[0055] 1. Dry at 480℃ for 24 hours, then grind.

[0056] Step 2: DBD plasma fluorination modification treatment of the packing material 2.1 Same as steps 2.1-2.3 in Example 1.

[0057] 2.2 Set the voltage to 3.0kV, the frequency to 10kHz, and the processing time to 15min.

[0058] 2.3 The rest is the same as in Example 1.

[0059] Step 3: Preparation of epoxy resin composite coating samples 3.1 Weigh 13.35g of the synergistic modified composite filler.

[0060] 3.2 Add to 100g of E51 resin and disperse for 20min.

[0061] 3.3 Add 25g of curing agent, 8g of toughening agent and 2.0g of accelerator in sequence, and stir for 40 minutes.

[0062] 3.4 Degassing, injection molding, and gradient curing.

[0063] 3.5 Cooling and demolding.

[0064] Example 4 (1% filler + 15 min plasma + 25 parts curing agent) Target filler content: 1% Matrix formulation: E51 100g, curing agent 25g, toughening agent 8g, accelerator 2.0g; Total matrix mass: 135.0g; Total required mass of packing material: m = (1% / 99%) × 135.0 = 1.364g ≈ 1.36g; Of which: 0.68g of nano-ZnO and 0.68g of short-cut basalt fiber; Step 1: Packing coupling modification treatment 1.1 Weigh 0.68g of nano ZnO and 0.68g of short-cut basalt fiber, and dry them.

[0065] 1.2 Add 15 mL of anhydrous ethanol, incubate in a 50°C water bath, stir at 4500 rpm and sonicate for 20 min.

[0066] 1.3 Add 0.136g of KH560 and 0.068g of deionized water, and stir for 40 minutes.

[0067] 1. Dry at 480℃ for 24 hours, then grind.

[0068] Step 2: DBD plasma fluorination modification treatment of the packing material 2.1 Same as steps 2.1-2.3 in Example 1.

[0069] 2.2 Set the voltage to 3.0kV, the frequency to 10kHz, and the processing time to 15min.

[0070] 2.3 The rest is the same as in Example 1.

[0071] Step 3: Preparation of epoxy resin composite coating samples 3.1 Weigh 1.36g of the synergistic modified composite filler.

[0072] 3.2 Add to 100g of E51 resin and disperse for 20min.

[0073] 3.3 Add 25g of curing agent, 8g of toughening agent and 2.0g of accelerator in sequence, and stir for 40 minutes.

[0074] 3.4 Degassing, injection molding, and gradient curing.

[0075] 3.5 Cooling and demolding.

[0076] Example 5 (9% filler + 5 min plasma + 15 parts curing agent) Target filler content: 9%; Matrix formulation: E51 100g, curing agent 15g, toughening agent 3g, accelerator 0.5g; Total matrix mass: 118.5g; Total required mass of packing material: m = (9% / 91%) × 118.5 = 11.72g ≈ 11.72g; Of which: 5.86g of nano ZnO and 5.86g of short-cut basalt fiber; Step 1: Packing coupling modification treatment 1.1 Weigh 5.86g of nano ZnO and 5.86g of short-cut basalt fiber, and dry them.

[0077] 1.2 Add 80 mL of anhydrous ethanol, incubate in a 50°C water bath, stir at 4500 rpm and sonicate for 40 min.

[0078] 1.3 Add 1.172g of KH560 and 0.586g of deionized water, and stir for 40 minutes.

[0079] 1. Dry at 480℃ for 24 hours, then grind.

[0080] Step 2: DBD plasma fluorination modification treatment of the packing material 2.1 Same as steps 2.1-2.3 in Example 1.

[0081] 2.2 Set voltage to 2.0kV, frequency to 8kHz, and processing time to 5min.

[0082] 2.3 The rest is the same as in Example 1.

[0083] Step 3: Preparation of epoxy resin composite coating samples 3.1 Weigh 11.72g of the synergistic modified composite filler.

[0084] 3.2 Add to 100g of E51 resin and disperse for 20min.

[0085] 3.3 Add 15g of curing agent, 3g of toughening agent and 0.5g of accelerator in sequence, and stir for 40 minutes.

[0086] 3.4 Degassing, injection molding, and gradient curing.

[0087] 3.5 Cooling and demolding.

[0088] Example 6 (5% filler + 7 min plasma + 18 parts curing agent, 6 parts toughening agent, 1.2 parts accelerator) Target filler content: 5%; Matrix formulation: E51 100g, curing agent 18g, toughening agent 6g, accelerator 1.2g; Total mass of the matrix: 100 + 18 + 6 + 1.2 = 125.2 g; Total required mass of packing material: m = (5% / 95%) × 125.2 = 6.589g ≈ 6.59g; Of which: 3.295g of nano-ZnO and 3.295g of short-cut basalt fiber; Step 1: Packing coupling modification treatment 1.1 Weigh 3.295g of nano ZnO and 3.295g of short-cut basalt fiber, and dry them.

[0089] 1.2 Add 50 mL of anhydrous ethanol, incubate in a 50°C water bath, stir at 4500 rpm and sonicate for 30 min.

[0090] 1.3 Add 0.659g of KH560 and 0.3295g of deionized water, and stir for 40 minutes.

[0091] 1. Dry at 480℃ for 24 hours, then grind.

[0092] Step 2: DBD plasma fluorination modification treatment of the packing material 2.1 Same as steps 2.1-2.3 in Example 1.

[0093] 2.2 Set the voltage to 2.3kV, the frequency to 8.5kHz, and the processing time to 7min.

[0094] 2.3 The rest is the same as in Example 1.

[0095] Step 3: Preparation of epoxy resin composite coating samples 3.1 Weigh 6.59g of the synergistic modified composite filler.

[0096] 3.2 Add to 100g of E51 resin and disperse for 20min.

[0097] 3.3 Add 18g of curing agent, 6g of toughening agent and 1.2g of accelerator in sequence, and stir for 40 minutes.

[0098] 3.4 Degassing, injection molding, and gradient curing.

[0099] 3.5 Cooling and demolding.

[0100] In summary, Examples 1 to 6 fully demonstrate the feasibility and technical effects of the present invention: Total filler content coverage range: Examples 1 and 4 (1 wt%), Examples 2 and 6 (5 wt%), and Examples 3 and 5 (9 wt%) fully cover the defined filler content range of 1 wt% to 9 wt%, with 5 wt% being the optimal content (Examples 2 and 6).

[0101] The proportions of the matrix components covered the following ranges: Examples 1 and 5 used 15 parts curing agent, 3 parts toughening agent, and 0.5 parts accelerator; Examples 2 and 6 used 18-20 parts curing agent, 5-6 parts toughening agent, and 1.0-1.2 parts accelerator; Examples 3 and 4 used 25 parts curing agent, 8 parts toughening agent, and 2.0 parts accelerator, which fully covered the defined proportion range.

[0102] The plasma fluorination process parameters cover the following ranges: Examples 1 and 5 use a processing time of 5 min, a voltage of 2.0 kV, and a frequency of 8 kHz; Example 2 uses a processing time of 10 min, a voltage of 2.5 kV, and a frequency of 9 kHz; Examples 3 and 4 use a processing time of 15 min, a voltage of 3.0 kV, and a frequency of 10 kHz; Example 6 uses a processing time of 7 min, a voltage of 2.3 kV, and a frequency of 8.5 kHz, which fully covers the range of process parameters defined in this scheme.

[0103] Consistency of technical effects: All embodiments exhibit good mechanical and electrical insulation properties. For example, Figure 2 and Figure 3 As shown, Example 2 (5wt% filler, plasma treatment for 10 min, matrix ratio 20 / 5 / 1) exhibits the best overall performance: tensile strength 19.45 MPa, volume resistivity 2.53 × 10¹. 5 Ω·cm, breakdown field strength 39.68kV / mm. Based on the synergistic effect of the process of this invention, it is reasonable to expect that the performance of the other embodiments will also be significantly better than that of the unmodified pure epoxy resin system, demonstrating the universality and stability within the scope of this invention.

[0104] The above embodiments fully demonstrate that by employing the positive synergistic modification process of the present invention, which involves "silane coupling grafting followed by plasma fluorination modification," and combined with a 1:1 composite system of nano-ZnO and short-cut basalt fiber, epoxy resin-based composite coatings with synergistically improved mechanical and electrical insulation properties can be obtained within the parameter range of 1wt% to 9wt% total filler content, matrix component ratio (based on 100 parts of epoxy resin), 15 to 25 parts curing agent, 3 to 8 parts toughening agent, 0.5 to 2 parts accelerator, plasma treatment time of 5 to 15 min, voltage of 2.0 to 3.0 kV, and frequency of 8 to 10 kHz. This is particularly suitable for the surface protection of wind turbine blades.

Claims

1. A plasma-modified epoxy resin coating for wind turbine blades, characterized in that, The coating is formed by curing an epoxy resin matrix composition and a modified filler uniformly dispersed therein; The epoxy resin matrix composition comprises epoxy resin, curing agent, toughening agent and accelerator; The modified filler consists of nano zinc oxide and short-cut basalt fibers that have been surface modified with silane coupling agent and then fluorinated by dielectric barrier discharge plasma, with a mass ratio of nano zinc oxide to short-cut basalt fibers of 1:

1. The total mass of modified fillers accounts for 1% to 9% of the total mass of the coating.

2. The plasma-fluorinated modified epoxy resin wind turbine blade coating according to claim 1, characterized in that, The total mass of the modified filler accounts for 5% of the total mass of the coating.

3. The plasma-fluorinated modified epoxy resin wind turbine blade coating according to claim 1, characterized in that, The silane coupling agent is KH560, and the working gas for the dielectric barrier discharge plasma fluorination treatment is CF4; or the silane coupling agent is KH550 or KH570, and the working gas is SF6 or C4F8.

4. The plasma-fluorinated modified epoxy resin wind turbine blade coating according to claim 1, characterized in that, Based on 100 parts by weight of epoxy resin, the curing agent is 15-25 parts by weight, the toughening agent is 3-8 parts by weight, and the accelerator is 0.5-2 parts by weight.

5. The method for preparing plasma-modified epoxy resin wind turbine blade coating as described in any one of claims 1 to 4, characterized in that, Includes the following steps: Step 1: Mix nano zinc oxide and chopped basalt fibers at a mass ratio of 1:1, add silane coupling agent and deionized water to carry out surface modification reaction, and obtain coupling modified filler after drying; Step 2: Place the coupling modified filler in a dielectric barrier discharge plasma reaction chamber and perform plasma fluorination treatment using fluorine-containing gas as the working gas to obtain the synergistic modified filler. Step 3: Disperse the synergistic modified filler in epoxy resin, then add curing agent, toughening agent and accelerator, mix evenly, and then degas and gradient cure to form the composite coating on the surface of wind turbine blade.

6. The method for preparing plasma-modified epoxy resin wind turbine blade coating according to claim 5, characterized in that, In step 1, the silane coupling agent is KH560, and the addition amount is 10g of KH560 per 100g of filler, and the addition amount of deionized water is 5g per 100g of filler; the modification reaction conditions are: 50℃ constant temperature water bath, mechanical stirring and ultrasonic dispersion treatment for 20min~40min, and then drying at 80℃ until dry.

7. The method for preparing plasma-modified epoxy resin wind turbine blade coating according to claim 5, characterized in that, In step 2, the fluorine-containing gas is CF4; the dielectric barrier discharge plasma treatment parameters are: voltage 2.0kV~3.0kV, frequency 8kHz~10kHz, cavity gas pressure below 10Pa, and treatment time 5min~15min.

8. The method for preparing plasma-modified epoxy resin wind turbine blade coating according to claim 5, characterized in that, In step 3, the gradient curing is carried out at 100℃, 110℃, 120℃, 140℃ and 150℃ for 1 hour each.

9. The method for preparing plasma-modified epoxy resin wind turbine blade coating according to claim 5, characterized in that, The total amount of the synergistic modified filler added accounts for 5% of the total mass of the coating.

10. A wind turbine blade, characterized in that: Its surface is coated with the plasma fluorinated modified epoxy resin wind turbine blade coating according to any one of claims 1 to 4, or the plasma fluorinated modified epoxy resin wind turbine blade coating is formed on its surface by the preparation method according to any one of claims 5 to 9.

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