Wind power blade protective coating and preparation method thereof

Abstract

The invention relates to the technical field of coatings, in particular to a wind power blade protective coating and a preparation method thereof. The preparation method comprises the following steps: preparing polyhydroxyalkanoate grafted modified sepiolite; preparing a composite anti-ultraviolet filler; preparing a copolymer emulsion; and preparing the wind power blade protective coating. Lignin and dopamine monomers are compounded to form a lignin / polydopamine composite material, zinc ions are introduced and inserted into the lignin / polydopamine composite material, finally, the composite anti-ultraviolet filler is obtained, lignin is biomass waste, low in cost and reproducible, rich phenolic hydroxyl groups and amino groups can be introduced through polydopamine coating, and the composite anti-ultraviolet filler is prepared. According to the invention, lignin is added to enhance the chemical activity and adsorption capacity, polydopamine can chelate zinc ions, promote uniform nucleation of the zinc ions on the surface of the composite material and prevent agglomeration of free zinc ions, lignin and polydopamine have good ultraviolet absorption capacity and have synergistic interaction with broadband ultraviolet shielding of the zinc ions, and the full-wave band anti-ultraviolet performance is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of coating preparation, and particularly relates to a wind turbine blade protection coating and a preparation method thereof. Background Art

[0002] With the continuous progress of technology and the expansion of the market scale, the cost of wind power generation has gradually decreased, making its competitiveness in the energy market continuously enhanced. In some regions, the cost of wind power generation has approached or even fallen below the cost of traditional fossil fuel power generation. This has led to a gradual increase in the proportion of wind power generation in the global energy structure, providing strong support for achieving energy transformation and sustainable development. Wind turbine blades are key components of wind turbines. During operation, wind turbine blades are exposed to complex and changing environments for a long time and face multiple severe environmental tests, mainly including strong wind loads, sand and dust impacts, ultraviolet radiation, and some other tests. Wind turbine blades need to withstand continuous wind speeds of 10 - 25 m / s and extreme gusts. Long-term alternating stresses can easily cause material fatigue. In some areas where wind power is used, the average annual ultraviolet radiation dose can reach 5000 MJ / m 2 , resulting in the degradation of the polymer matrix, surface wear of the wind turbine blade material, and performance decline.

[0003] Therefore, a wind turbine blade protection coating is needed to extend the service life of the blade. Existing protection coatings all contain components with anti-ultraviolet aging and wear resistance. For example, a coating containing nano-TiO2 / ZnO can reflect more than 90% of ultraviolet rays, thereby improving the anti-ultraviolet ability. However, under long-term wind abrasion and extreme meteorological environments, the interfacial adhesion of the protection coating will decrease. For example, Patent CN111171688A discloses a wind turbine blade edge protection paint based on bio-based polyols for long-term protection of wind turbine blade edges. It has good elongation at break, impact strength, adhesion, and comprehensive abilities such as anti-icing, weather resistance, wear resistance, high and low temperature resistance, and rain erosion resistance. However, its film hardness and ultraviolet protection ability under climate aging and radiation exposure have not been tested. Therefore, the present invention provides a wind turbine blade protection coating and a preparation method thereof to improve the anti-ultraviolet performance in the full wavelength range and still have good hardness and protection ability after aging to solve the above problems.

[0004] It should be noted that the information disclosed in the above background art section is only used to enhance the understanding of the background of the present disclosure. Summary of the Invention

[0005] Aiming at the deficiencies of the existing technology, the purpose of the present invention is to provide a wind turbine blade protection coating and a preparation method thereof.

[0006] A preparation method of a wind turbine blade protection coating includes the following steps: S1: Prepare polyhydroxyalkanoate graft-modified sepiolite Sepiolite is added to hydrochloric acid for treatment to obtain acid-treated sepiolite powder. The acid-treated sepiolite powder is mixed and reacted with a polyhydroxyalkanoate solution to obtain polyhydroxyalkanoate-grafted modified sepiolite. S2: Preparation of composite anti-ultraviolet filler Lignin and hydrochloric acid dopamine monomers are subjected to a shaking reaction to obtain a lignin / polydopamine composite material. An ethanol solution of zinc acetate and an ethanol solution of sodium hydroxide are mixed, and then the lignin / polydopamine composite material is added to obtain an intermediate product. Zinc nitrate and hexamethylenetetramine are added to deionized water, and then the intermediate product is added, and the reaction is carried out to obtain a composite anti-ultraviolet filler. S3: Preparation of copolymer emulsion An anionic surfactant is added to an aqueous polyurethane emulsion, and then vinyl acetate, butyl acrylate, acrylic acid, and 2-hydroxyethyl methacrylate are added. Subsequently, an initiator is added, and the reaction is carried out to obtain a copolymer emulsion. S4: Preparation of wind turbine blade protection coating An aqueous polyurethane emulsion, deionized water, and the copolymer emulsion are mixed to prepare a mixed solution. Polyhydroxyalkanoate-grafted modified sepiolite and the composite anti-ultraviolet filler are added to the mixed solution to obtain a wind turbine blade protection coating.

[0007] Furthermore, the preparation of polyhydroxyalkanoate-grafted modified sepiolite in step S1 specifically includes the following steps: S1.1: Sepiolite is added to 1-1.5 mol / L hydrochloric acid at a material-liquid ratio of 1 g:(20-25) mL, magnetically stirred for 4-4.5 h and then filtered by suction. The suspension is adjusted to neutral with deionized water, then oscillated and dispersed for 30-35 min, filtered by suction, dried and ground to obtain acid-treated sepiolite powder. S1.2: Polyhydroxyalkanoate is added to chloroform, and the mass ratio of polyhydroxyalkanoate to chloroform is 1:(5-8) to obtain a polyhydroxyalkanoate solution. The acid-treated sepiolite powder and the polyhydroxyalkanoate solution are mixed at a mass ratio of 1:10, then the water bath is heated to 80-100 °C, and then p-toluenesulfonic acid accounting for 5-10% of the system mass is added, and the stirring reaction is carried out for 4-8 h. Subsequently, the solid is filtered to obtain a solid product, and the solid product is washed 3 times with ethanol, and left to stand and dry to obtain polyhydroxyalkanoate-grafted modified sepiolite.

[0008] Furthermore, the preparation of the composite anti-ultraviolet filler in step S2 specifically includes the following steps: S2.1: 3-5 parts by mass of lignin and 6-10 parts by mass of hydrochloric acid dopamine monomers are dissolved in 20-25 parts by mass of Tris-HCl, and the shaking reaction is carried out on a shaker at room temperature for 12-15 h. Subsequently, centrifugation, washing with water, ultrasonic fragmentation, and high-pressure homogenization are carried out to obtain a lignin / polydopamine composite material. S2.2: Prepare zinc acetate ethanol solution with a concentration of 0.0125 mol / L and sodium hydroxide ethanol solution with a concentration of 0.02 mol / L respectively. Take 16 - 20 parts by mass of each of the two solutions, mix them, add 150 - 200 parts by mass of ethanol, stir evenly, then add 10 - 20 parts by mass of lignin / polydopamine composite material, and let it stand and react in a water bath at 60 - 65 °C for 1 - 1.5 h to obtain an intermediate product; S2.3: Add 3.5 - 4 parts by mass of zinc nitrate and 1.5 - 2 parts by mass of hexamethylenetetramine to 500 parts by mass of deionized water, stir for 10 - 15 min, then add 10 - 20 parts by mass of the intermediate product, let it stand and react in a water bath at 90 - 100 °C for 2 - 3 h, take it out and put it in a freeze dryer to dry for 4 - 5 h to obtain a composite anti-ultraviolet filler.

[0009] Further, the preparation of the copolymer emulsion in step S3 specifically includes the following steps: S3.1: Add deionized water and aqueous polyurethane emulsion into a reaction flask at a volume ratio of (5 - 10):1, heat up to 90 - 95 °C, and continuously stir at a speed of 100 - 120 r / min at this temperature for 2 - 2.5 h. Then lower the temperature to 55 - 60 °C, and use a constant pressure dropping funnel to add an anionic surfactant accounting for 2 - 5% of the system mass into the reaction flask, and stir for 3 - 5 min; S3.2: Mix vinyl acetate, butyl acrylate, acrylic acid and 2-hydroxyethyl methacrylate in a mass ratio of (50 - 60):(30 - 40):(2 - 5):(3 - 8), add them into the reaction flask, and the addition amount is 10 - 15% of the total system mass, and stir for 5 - 10 min; S3.3: Add an initiator accounting for 1 - 3% of the total system mass, raise the temperature to 65 - 70 °C, continuously react for 1 - 1.5 h, then raise the temperature to 75 - 80 °C, continuously react for 200 - 210 min, raise the temperature to 85 - 90 °C, carry out condensation reflux for 1 - 1.5 h, and then lower the temperature to 40 - 45 °C, and adjust the pH value in the reaction flask to 7 - 7.5 to obtain a copolymer emulsion.

[0010] Further, the preparation of the wind turbine blade protection coating in step S4 specifically includes the following steps: S4.1: Mix the aqueous polyurethane emulsion and deionized water, heat it in a water bath to 90 - 95 °C, stir for 1 - 1.5 h, then lower the temperature to 50 - 55 °C, control the mass fraction of the aqueous polyurethane emulsion to be 12 - 15 wt%, then add the copolymer emulsion, and stir for another 10 min to obtain a mixed liquid; S4.2: Ultrasonically disperse the mixture for 5 - 10 min, then mechanically stir at a speed of 60 - 80 r / min for 30 - 60 min. During the stirring process, add polyhydroxyalkanoate graft-modified sepiolite and composite anti-ultraviolet filler. After the stirring is completed, add an antifoaming agent and stir again at a speed of 150 - 200 r / min for 5 - 10 min to obtain the wind turbine blade protection coating.

[0011] Further, the polyhydroxyalkanoate is specifically poly-3-hydroxybutyrate.

[0012] Further, the anionic surfactant is sodium dodecylbenzenesulfonate, and the initiator is an 8 - 10 wt% aqueous ammonium persulfate solution.

[0013] Further, the mass ratio of the copolymer emulsion, 12 wt% aqueous polyurethane emulsion solution, polyhydroxyalkanoate graft-modified sepiolite, composite anti-ultraviolet filler, and antifoaming agent in the wind turbine blade protection coating is (45 - 50):(45 - 50):(30 - 40):(10 - 20):0.1.

[0014] Further, the antifoaming agent is a silicone resin antifoaming agent.

[0015] A wind turbine blade protection coating is prepared by the preparation method of the above-mentioned wind turbine blade protection coating.

[0016] As can be seen from the above technical solutions, the present disclosure has at least the following advantages and positive effects: 1. In the present invention, polyhydroxyalkanoate is grafted and modified with sepiolite. Hydrochloric acid treatment can dissolve the impurities in sepiolite, increase the specific surface area and porosity, and expose more active sites, laying a foundation for the subsequent grafting reaction. The surface of sepiolite after acid treatment is rich in hydroxyl groups, which can directly react with the polyhydroxyalkanoate solution. The steps are efficiently connected. The sepiolite rich in hydroxyl groups introduces hydrophobic segments through polyhydroxyalkanoate grafting, making its compatibility with the organic coating better, avoiding the sedimentation or agglomeration of sepiolite particles, and ensuring the uniformity of the coating. The flexible chain segments of polyhydroxyalkanoate can improve the toughness of sepiolite while retaining the reinforcing effect of its rigid skeleton, realizing the improvement of the mechanical properties of the coating paint such as hardness and wear resistance. Moreover, through the reaction, the chemical bonds in sepiolite form covalent bonds with the groups of polyhydroxyalkanoate, which is more stable than physical mixing, avoiding debonding at the filler-matrix interface, thereby improving the adhesion of the coating and preventing peeling.

[0017] 2. After the lignin and dopamine monomers are compounded to form a lignin / polydopamine composite material, zinc ions are introduced and inserted into it, and finally a composite anti-ultraviolet filler is obtained. Lignin is a biomass waste with low cost and renewable. Through polydopamine coating, abundant phenolic hydroxyl groups and amino groups can be introduced to enhance its chemical activity and adsorption capacity. Polydopamine can chelate zinc ions, promote the uniform nucleation of zinc ions on the surface of the composite material, and prevent the aggregation of free zinc ions. Lignin and polydopamine have good ultraviolet absorption capacity, and synergistically enhance the broadband ultraviolet shielding of zinc ions to improve the anti-ultraviolet performance in the whole wavelength range.

[0018] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The accompanying drawings herein are incorporated into the specification and form a part of the specification, showing embodiments consistent with the present disclosure, and are used together with the specification to explain the principles of the present disclosure. Obviously, the accompanying drawings in the following description are only some embodiments of the present disclosure, and those of ordinary skill in the art can obtain other drawings based on these drawings without creative efforts. In the drawings: Figure 1 It is a flowchart of a preparation method of a wind turbine blade protection coating adopted in an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0020] Example embodiments will now be described more fully with reference to the accompanying drawings. However, the example embodiments can be implemented in various forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided so that this disclosure will be more complete and comprehensive, and will fully convey the concept of the example embodiments to those skilled in the art.

[0021] Example 1

[0022] A preparation method of a wind turbine blade protection coating, as Figure 1 shown, includes the following steps: S1: Prepare polyhydroxyalkanoate graft-modified sepiolite S1.1: Add sepiolite to 1 mol / L hydrochloric acid at a solid-liquid ratio of 1 g:20 mL, magnetically stir for 4 h, then filter by suction, adjust the suspension to neutral with deionized water, then oscillate and disperse for 30 min, filter by suction, dry and grind to obtain acid-treated sepiolite powder; S1.2: Add polyhydroxyalkanoate into chloroform at a mass ratio of polyhydroxyalkanoate to chloroform of 1:5 to obtain a polyhydroxyalkanoate solution. Mix acid-treated sepiolite powder with the polyhydroxyalkanoate solution at a mass ratio of 1:10. Then, raise the temperature in a water bath to 80 °C, add p-toluenesulfonic acid accounting for 5% of the system mass, stir and react for 4 h. Subsequently, filter to obtain a solid. Wash the solid with ethanol three times and let it stand for drying to obtain polyhydroxyalkanoate-grafted modified sepiolite, where the hydroxyalkanoate is specifically poly-3-hydroxybutyrate.

[0023] S2: Prepare a composite anti-ultraviolet filler S2.1: Dissolve 3 parts by mass of lignin and 6 parts by mass of hydrochloric acid dopamine monomer in 20 parts by mass of 10 mmol / L Tris-HCl. After shaking and reacting on a shaker at room temperature for 12 h, then centrifuge, wash with water, ultrasonically crush, and homogenize under high pressure to obtain a lignin / polydopamine composite material; S2.2: Prepare zinc acetate ethanol solution with a concentration of 0.0125 mol / L and sodium hydroxide ethanol solution with a concentration of 0.02 mol / L respectively. Take 16 parts by mass of each of the two solutions, mix them, add 150 parts by mass of ethanol, stir evenly, then add 10 parts by mass of the lignin / polydopamine composite material, and let it stand and react in a 60 °C water bath for 1 h to obtain an intermediate product; S2.3: Add 3.5 parts by mass of zinc nitrate and 1.5 parts by mass of hexamethylenetetramine into 500 parts by mass of deionized water, stir for 10 min, then add 10 parts by mass of the intermediate product, let it stand and react in a 90 °C water bath for 2 h. Take it out and dry it in a freeze dryer for 4 h to obtain a composite anti-ultraviolet filler.

[0024] S3: Preparation of copolymer emulsion S3.1: Add deionized water and aqueous polyurethane emulsion into a reaction flask at a volume ratio of 5:1, raise the temperature to 90 °C, and continuously stir at a speed of 100 r / min at this temperature for 2 h. Then, lower the temperature to 55 °C, use a constant-pressure dropping funnel to add sodium dodecylbenzenesulfonate, an anionic surfactant accounting for 2% of the system mass, into the reaction flask, and stir for 3 min; S3.2: Mix vinyl acetate, butyl acrylate, acrylic acid, and 2-hydroxyethyl methacrylate at a mass ratio of 50:30:2:3, add them into the reaction flask, and the addition amount is 10% of the total system mass, and stir for 5 min; S3.3: Add an initiator accounting for 1% of the total system mass. The initiator is an 8 wt% aqueous solution of ammonium persulfate, raise the temperature to 65 °C, continuously react for 1 - 1.5 h, then raise the temperature to 75 °C, continuously react for 200 min, raise the temperature to 85 °C, carry out condensation reflux for 1 h, and then lower the temperature to 40 °C. Adjust the pH value in the reaction flask to 7 to obtain a copolymer emulsion.

[0025] S4: Preparation of protective coating for wind turbine blades S4.1: After mixing the aqueous polyurethane emulsion powder with deionized water, heat it in a water bath to 90 °C, stir for 1 h, then lower the temperature to 50 °C, control the mass fraction of the aqueous polyurethane emulsion to be 12 wt%, then add the copolymer emulsion, and stir for another 10 min to obtain a mixed solution; S4.2: Ultrasonically disperse the mixed solution for 5 min, then mechanically stir it at a speed of 60 r / min for 30 min. During the stirring process, add polyhydroxyalkanoate graft-modified sepiolite and composite ultraviolet-resistant filler. After the stirring ends, add an antifoaming agent and stir again at a speed of 150 r / min for 5 min to obtain the protective coating for wind turbine blades.

[0026] Among them, the mass ratio of the copolymer emulsion, 12 wt% aqueous polyurethane emulsion solution, polyhydroxyalkanoate graft-modified sepiolite, composite ultraviolet-resistant filler and antifoaming agent in the protective coating for wind turbine blades is 45:45:30:10:0.1.

[0027] Example 2

[0028] A preparation method of a protective coating for wind turbine blades is as Figure 1 shown, including the following steps: S1: Preparation of polyhydroxyalkanoate graft-modified sepiolite S1.1: Add sepiolite to 1.5 mol / L hydrochloric acid at a solid-liquid ratio of 1 g:25 mL, magnetically stir for 4 h and then filter by suction. Adjust the suspension to neutral with deionized water, then oscillate and disperse for 35 min, filter by suction, dry and grind to obtain acid-treated sepiolite powder; S1.2: Add polyhydroxyalkanoate to chloroform, and the mass ratio of polyhydroxyalkanoate to chloroform is 1:5 to obtain a polyhydroxyalkanoate solution. Mix the acid-treated sepiolite powder and the polyhydroxyalkanoate solution at a mass ratio of 1:10, then raise the temperature in a water bath to 100 °C, add p-toluenesulfonic acid accounting for 5% of the system mass, stir and react for 8 h, then filter to obtain a solid. Wash the solid 3 times with ethanol, let it stand and dry to obtain polyhydroxyalkanoate graft-modified sepiolite, where the hydroxy fatty acid ester is specifically poly-3-hydroxybutyrate.

[0029] S2: Preparation of composite ultraviolet-resistant filler S2.1: Dissolve 3 parts by mass of lignin and 6 parts by mass of hydrochloric acid dopamine monomer in 25 parts by mass of 10 mmol / L Tris-HCl. React on a shaker at room temperature for 15 h, then centrifuge, wash with water, ultrasonically break and homogenize under high pressure to obtain a lignin / polydopamine composite material; S2.2: Prepare a zinc acetate ethanol solution with a concentration of 0.0125 mol / L and a sodium hydroxide ethanol solution with a concentration of 0.02 mol / L respectively. Take 16 mass parts of each of the two solutions, mix them, add 150 mass parts of ethanol, stir evenly, then add 10 mass parts of the lignin / polydopamine composite material, and let it stand and react in a water bath at 65 °C for 1.5 h to obtain an intermediate product; S2.3: Add 3.5 mass parts of zinc nitrate and 1.5 mass parts of hexamethylenetetramine to 500 mass parts of deionized water, stir for 15 min, then add 10 mass parts of the intermediate product, let it stand and react in a water bath at 100 °C for 2 h, take it out and dry it in a freeze dryer for 5 h to obtain a composite anti-ultraviolet filler.

[0030] S3: Preparation of copolymer emulsion S3.1: Add deionized water and aqueous polyurethane emulsion to the reaction flask at a volume ratio of 5:1, heat up to 90 °C, and continuously stir at a speed of 120 r / min at this temperature for 2.5 h. Then lower the temperature to 55 °C, and use a constant pressure dropping funnel to add 2% of the system mass of the anionic surfactant sodium dodecylbenzenesulfonate to the reaction flask and stir for 5 min; S3.2: Mix vinyl acetate, butyl acrylate, acrylic acid and 2-hydroxyethyl methacrylate in a mass ratio of 50:30:2:3, add them to the reaction flask, and the addition amount is 10% of the total system mass, and stir for 10 min; S3.3: Add 1% of the total system mass of the initiator. The initiator is an 8 wt% aqueous solution of ammonium persulfate, and raise the temperature to 70 °C, continuously react for 1 - 1.5 h and then raise the temperature to 80 °C, continuously react for 200 min, raise the temperature to 90 °C, carry out condensation reflux for 1 h, then lower the temperature to 45 °C, and adjust the pH value in the reaction flask to 7 to obtain a copolymer emulsion.

[0031] S4: Preparation of wind turbine blade protection coating S4.1: Mix the aqueous polyurethane emulsion powder with deionized water, heat it in a water bath to 95 °C, stir for 1 h, then lower the temperature to 50 °C, control the mass fraction of the aqueous polyurethane emulsion to be 12 wt%, then add the copolymer emulsion, and stir for another 10 min to obtain a mixed solution; S4.2: Ultrasonically disperse the mixed solution for 10 min, then mechanically stir at a speed of 80 r / min for 30 min. During the stirring process, add polyhydroxyalkanoate graft-modified sepiolite and the composite anti-ultraviolet filler. After the stirring is completed, add the defoaming agent and stir again at a speed of 200 r / min for 10 min to obtain the wind turbine blade protection coating.

[0032] Among them, the mass ratio of the copolymer emulsion, 12 wt% aqueous polyurethane emulsion solution, polyhydroxyalkanoate-grafted sepiolite, composite anti-ultraviolet filler and defoamer in the wind power blade protective coating is 45:45:30:10:0.1.

[0033] Example 3

[0034] A preparation method of a wind power blade protective coating is as Figure 1 shown, and includes the following steps: S1: Prepare polyhydroxyalkanoate-grafted sepiolite S1.1: Add sepiolite to 1 mol / L hydrochloric acid at a solid-liquid ratio of 1 g:25 mL, magnetically stir for 4 h and then filter by suction. Adjust the suspension to neutral with deionized water, then oscillate and disperse for 30 min, filter by suction, dry and grind to obtain acid-treated sepiolite powder; S1.2: Add polyhydroxyalkanoate to chloroform, and the mass ratio of polyhydroxyalkanoate to chloroform is 1:8 to obtain a polyhydroxyalkanoate solution. Mix the acid-treated sepiolite powder and the polyhydroxyalkanoate solution at a mass ratio of 1:10, then raise the temperature of the water bath to 80 °C, and then add 10% of the system mass of p-toluenesulfonic acid, stir and react for 4 h, then filter to obtain a solid, wash the solid 3 times with ethanol, and stand and dry to obtain polyhydroxyalkanoate-grafted sepiolite, where the hydroxy fatty acid ester is specifically poly-3-hydroxybutyrate.

[0035] S2: Prepare a composite anti-ultraviolet filler S2.1: Dissolve 5 parts by mass of lignin and 10 parts by mass of hydrochloric acid dopamine monomer in 20 parts by mass of 10 mmol / L Tris-HCl, shake and react on a shaker at room temperature for 12 h, then centrifuge, wash with water, ultrasonically crush and homogenize under high pressure to obtain a lignin / polydopamine composite material; S2.2: Prepare zinc acetate ethanol solutions with a concentration of 0.0125 mol / L and sodium hydroxide ethanol solutions with a concentration of 0.02 mol / L respectively. Take 20 parts by mass of each of the two solutions, mix them, add 200 parts by mass of ethanol and stir evenly, then add 20 parts by mass of the lignin / polydopamine composite material, and stand and react in a 60 °C water bath for 1 h to obtain an intermediate product; S2.3: Add 4 parts by mass of zinc nitrate and 2 parts by mass of hexamethylenetetramine to 500 parts by mass of deionized water, stir for 10 min, then add 20 parts by mass of the intermediate product, stand and react in a 90 °C water bath for 2 h, take it out and dry it in a freeze dryer for 4 h to obtain a composite anti-ultraviolet filler.

[0036] S3: Preparation of copolymer emulsion S3.1: Add deionized water and aqueous polyurethane emulsion into a reaction flask at a volume ratio of 10:1, heat up to 90 °C, and continuously stir at a speed of 100 r / min at this temperature for 2 h. Then lower the temperature to 55 °C, and use a constant-pressure dropping funnel to add sodium dodecylbenzenesulfonate, an anionic surfactant accounting for 2% of the system mass, into the reaction flask, and stir for 3 min; S3.2: Mix vinyl acetate, butyl acrylate, acrylic acid, and 2-hydroxyethyl methacrylate at a mass ratio of 60:40:5:8, add them into the reaction flask, and the addition amount is 10% of the total system mass, then stir for 5 min; S3.3: Add an initiator accounting for 3% of the total system mass. The initiator is an 8 wt% aqueous solution of ammonium persulfate, and raise the temperature to 65 °C. Continuously react for 1 - 1.5 h, then raise the temperature to 75 °C, continuously react for 200 min, raise the temperature to 85 °C, and carry out condensation reflux for 1 h. Then lower the temperature to 40 °C, and adjust the pH value in the reaction flask to 7 to obtain a copolymer emulsion.

[0037] S4: Prepare a protective coating for wind turbine blades S4.1: After mixing the aqueous polyurethane emulsion powder with deionized water, heat it in a water bath to 90 °C and stir for 1 h. Then lower the temperature to 50 °C, control the mass fraction of the aqueous polyurethane emulsion to be 12 wt%, and then add the copolymer emulsion, and stir for another 10 min to obtain a mixed solution; S4.2: Ultrasonically disperse the mixed solution for 5 min, then mechanically stir at a speed of 60 r / min for 30 min. During the stirring process, add polyhydroxyalkanoate graft-modified sepiolite and a composite ultraviolet-resistant filler. After the stirring ends, add an antifoaming agent, and stir again at a speed of 150 r / min for 5 min to obtain a protective coating for wind turbine blades.

[0038] Among them, the mass ratio of the copolymer emulsion, 12 wt% aqueous polyurethane emulsion solution, polyhydroxyalkanoate graft-modified sepiolite, composite ultraviolet-resistant filler, and antifoaming agent in the protective coating for wind turbine blades is 50:50:40:20:0.1.

[0039] Comparative Example 1: Compared with Example 1, the difference in Comparative Example 1 is that step S1.2 is not carried out, and acid-treated sepiolite is used instead of polyhydroxyalkanoate graft-modified sepiolite in step S4. Specifically: "S4.2: Ultrasonically disperse the mixed solution for 5 min, then mechanically stir at a speed of 60 r / min for 30 min. During the stirring process, add acid-treated sepiolite and a composite ultraviolet-resistant filler. After the stirring ends, add an antifoaming agent, and stir again at a speed of 150 r / min for 5 min to obtain a protective coating for wind turbine blades; Among them, the mass ratio of the copolymer emulsion, 12 wt% aqueous polyurethane emulsion solution, acid-treated sepiolite, composite anti-ultraviolet filler, and defoamer in the wind turbine blade protection coating is 45:45:30:10:0.1. The rest of the steps remain unchanged, and the obtained wind turbine blade protection coating is denoted as Comparative Example 1.

[0040] Comparative Example 2: Compared with Example 1, the difference in Comparative Example 2 is that lignin is used instead of the lignin / polydopamine composite material in step S2.2. Specifically: "S2.2: Prepare zinc acetate ethanol solutions with a concentration of 0.0125 mol / L and sodium hydroxide ethanol solutions with a concentration of 0.02 mol / L respectively. Take 16 mass parts of each of the two solutions, mix them, add 150 mass parts of ethanol, stir evenly, then add 10 mass parts of lignin, and let it stand and react in a 60°C water bath for 1 h to obtain an intermediate product." The rest of the steps remain unchanged, and the obtained wind turbine blade protection coating is denoted as Comparative Example 2.

[0041] Comparative Example 3: Compared with Example 1, the difference in Comparative Example 3 is that polydopamine is used instead of the lignin / polydopamine composite material in step S2.2. Specifically: "S2.2: Prepare zinc acetate ethanol solutions with a concentration of 0.0125 mol / L and sodium hydroxide ethanol solutions with a concentration of 0.02 mol / L respectively. Take 16 mass parts of each of the two solutions, mix them, add 150 mass parts of ethanol, stir evenly, then add 10 mass parts of polydopamine, and let it stand and react in a 60°C water bath for 1 h to obtain an intermediate product." The rest of the steps remain unchanged, and the obtained wind turbine blade protection coating is denoted as Comparative Example 3.

[0042] Comparative Example 4: Compared with Example 1, the difference in Comparative Example 4 is that the lignin / polydopamine composite material is used instead of the composite anti-ultraviolet filler in step S4. Specifically: "S4.2: Ultrasonically disperse the mixture for 5 min, then mechanically stir it at a speed of 60 r / min for 30 min. During the stirring process, add polyhydroxyalkanoate-grafted sepiolite and the composite anti-ultraviolet filler. After the stirring ends, add the defoamer and stir again at a speed of 150 r / min for 5 min to obtain the wind turbine blade protection coating; Among them, the mass ratio of the copolymer emulsion, 12 wt% aqueous polyurethane emulsion solution, polyhydroxyalkanoate-grafted sepiolite, lignin / polydopamine composite material, and defoamer in the wind turbine blade protection coating is 45:45:30:10:0.1." The rest of the steps remain unchanged.

[0043] Comparative Example 5: Comparative Example 5 is a commercially available wind turbine blade protection coating, which is an acrylic coating.

[0044] Examples 1-3 and Comparative Examples 2-5 were tested according to the method in GB / T 1865-2009 Paints and varnishes - Artificial weathering and exposure to artificial radiation - Filtered xenon-arc radiation, and the test results are shown in Table 1.

[0045] Examples 1-3 and Comparative Examples 1 and 5 were tested according to the method in GB / T 6739-2022 Paints and varnishes - Determination of film hardness by pencil test, and the test results are shown in Table 2.

[0046] Table 1 Loss of gloss rate (%) Color difference value ΔE Example 1 9 1.7 Example 2 8 1.6 Example 3 9 1.8 Comparative example 2 17 4.8 Comparative example 3 19 5.3 Comparative example 4 16 4.2 Comparative example 5 14 3.4 Table 2 Pencil hardness Example 1 2H Example 2 2H Example 3 2H Comparative example 1 B Comparative example 5 H As can be seen from Table 1, the gloss loss rate and color difference value of Examples 1-3 are both less than those of the comparative examples, indicating that the coatings of the examples have better ultraviolet light resistance than the comparative examples. Moreover, Comparative Example 5 is a commercially available product. It can be seen that the ultraviolet light resistance of the present disclosure is better than that of the commercially available product.

[0047] As can be seen from Table 2, the pencil hardness of Examples 1-3 is 2H, which is better than that of Comparative Example 1 and the commercially available product Comparative Example 5. It can be seen that the polyhydroxyalkanoate graft-modified sepiolite of the present invention provides wear resistance for the coating.

[0048] Those skilled in the art will readily conceive of other embodiments of the present disclosure after considering the specification and the practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of the present disclosure, which follow the general principles of the present disclosure and include common general knowledge or conventional technical means in the technical field not disclosed in the present disclosure. The specification and examples are only regarded as exemplary, and the true scope and spirit of the present disclosure are pointed out by the following claims.

[0049] It should be understood that the present disclosure is not limited to the exact structures described above and shown in the drawings, and various modifications and changes can be made without departing from its scope. The scope of the present disclosure is only limited by the appended claims.

Claims

1. A preparation method of a wind power blade protection coating, characterized in that, It includes the following steps: S1: Prepare polyhydroxyalkanoate graft-modified sepiolite Add sepiolite to hydrochloric acid for treatment to obtain acid-treated sepiolite powder, mix the acid-treated sepiolite powder with polyhydroxyalkanoate solution for reaction to obtain polyhydroxyalkanoate graft-modified sepiolite; S2: Prepare composite anti-ultraviolet filler React lignin and hydrochloric acid dopamine monomer by shaking to obtain lignin / polydopamine composite material. Mix zinc acetate ethanol solution and sodium hydroxide ethanol solution, then add the lignin / polydopamine composite material to obtain an intermediate product. Add zinc nitrate and hexamethylenetetramine to deionized water, then add the intermediate product and react to obtain the composite anti-ultraviolet filler; S3: Preparation of copolymer emulsion Add an anionic surfactant to the aqueous polyurethane emulsion, then add vinyl acetate, butyl acrylate, acrylic acid and 2-hydroxyethyl methacrylate, and then add an initiator and react to obtain a copolymer emulsion; S4: Prepare the protective coating for wind turbine blades Mix the aqueous polyurethane emulsion, deionized water and the copolymer emulsion to prepare a mixture, and add polyhydroxyalkanoate graft-modified sepiolite and the composite anti-ultraviolet filler to the mixture to obtain the protective coating for wind turbine blades.

2. The preparation method of a wind power blade protection coating according to claim 1, characterized in that, In step S1, the polyhydroxyalkanoate graft-modified sepiolite is prepared, which specifically includes the following steps: S1.1: Add sepiolite to 1-1.5 mol / L hydrochloric acid at a material-liquid ratio of 1 g:(20-25) mL, magnetically stir for 4-4.5 h and then filter by suction. Adjust the suspension to neutral with deionized water, then shake and disperse for 30-35 min, filter by suction, dry and grind to obtain acid-treated sepiolite powder; S1.2: Add polyhydroxyalkanoate to chloroform, and the mass ratio of polyhydroxyalkanoate to chloroform is 1:(5-8) to obtain a polyhydroxyalkanoate solution. Mix the acid-treated sepiolite powder and the polyhydroxyalkanoate solution at a mass ratio of 1:10, then raise the temperature of the water bath to 80-100 °C, and then add p-toluenesulfonic acid accounting for 5-10% of the system mass, stir and react for 4-8 h, then filter to obtain a solid, wash the solid 3 times with ethanol, and stand and dry to obtain polyhydroxyalkanoate graft-modified sepiolite.

3. The preparation method of a wind power blade protection coating according to claim 2, characterized in that, In step S2, the composite anti-ultraviolet filler is prepared, which specifically includes the following steps: S2.1: Dissolve 3-5 parts by mass of lignin and 6-10 parts by mass of hydrochloric acid dopamine monomer in 20-25 parts by mass of Tris-HCl, react by shaking on a shaker at room temperature for 12-15 h, then centrifuge, wash with water, ultrasonically crush and homogenize under high pressure to obtain a lignin / polydopamine composite material; S2.2: Prepare zinc acetate ethanol solution with a concentration of 0.0125 mol / L and sodium hydroxide ethanol solution with a concentration of 0.02 mol / L respectively. Take 16-20 parts by mass of each of the two solutions, mix them, add 150-200 parts by mass of ethanol and stir evenly, then add 10-20 parts by mass of the lignin / polydopamine composite material, and stand and react in a water bath at 60-65 °C for 1-1.5 h to obtain an intermediate product; S2.3: Add 3.5 - 4 parts by mass of zinc nitrate and 1.5 - 2 parts by mass of hexamethylenetetramine into 500 parts by mass of deionized water, stir for 10 - 15 min, then add 10 - 20 parts by mass of the intermediate product, let it stand and react in a water bath at 90 - 100 °C for 2 - 3 h, take it out and dry it in a freeze dryer for 4 - 5 h to obtain the composite anti - ultraviolet filler.

4. The preparation method of a wind power blade protection coating according to claim 3, wherein, Step S3 Preparation of the copolymer emulsion, specifically including the following steps: S3.1: Add deionized water and aqueous polyurethane emulsion into the reaction flask at a volume ratio of (5 - 10):1, heat up to 90 - 95 °C, and continuously stir at a speed of 100 - 120 r / min at this temperature for 2 - 2.5 h. Then lower the temperature to 55 - 60 °C, use a constant - pressure dropping funnel to add an anionic surfactant accounting for 2 - 5% of the system mass into the reaction flask, and stir for 3 - 5 min; S3.2: Mix vinyl acetate, butyl acrylate, acrylic acid and 2 - hydroxyethyl methacrylate in a mass ratio of (50 - 60):(30 - 40):(2 - 5):(3 - 8), add them into the reaction flask, and the addition amount is 10 - 15% of the total system mass, and stir for 5 - 10 min; S3.3: Add an initiator accounting for 1 - 3% of the total system mass, raise the temperature to 65 - 70 °C, continuously react for 1 - 1.5 h, then raise the temperature to 75 - 80 °C, continuously react for 200 - 210 min, raise the temperature to 85 - 90 °C, carry out condensation reflux for 1 - 1.5 h, then lower the temperature to 40 - 45 °C, and adjust the pH value in the reaction flask to 7 - 7.5 to obtain the copolymer emulsion.

5. The preparation method of a wind power blade protection coating according to claim 4, characterized in that, Step S4 Preparation of the wind turbine blade protection coating, specifically including the following steps: S4.1: Mix the aqueous polyurethane emulsion and deionized water, heat it in a water bath to 90 - 95 °C, stir for 1 - 1.5 h, then lower the temperature to 50 - 55 °C, control the mass fraction of the aqueous polyurethane emulsion to be 12 - 15 wt%, then add the copolymer emulsion, and stir for another 10 min to obtain a mixed solution; S4.2: Ultrasonically disperse the mixed solution for 5 - 10 min, then mechanically stir at a speed of 60 - 80 r / min for 30 - 60 min. During the stirring process, add polyhydroxyalkanoate - grafted sepiolite and the composite anti - ultraviolet filler. After the stirring ends, add an antifoaming agent, and stir again at a speed of 150 - 200 r / min for 5 - 10 min to obtain the wind turbine blade protection coating.

6. The preparation method of a wind power blade protection coating according to claim 4, characterized in that The polyhydroxyalkanoate is specifically poly - 3 - hydroxybutyrate.

7. The preparation method of a wind power blade protection coating according to claim 4, characterized in that, The anionic surfactant is sodium dodecylbenzenesulfonate, and the initiator is an 8 - 10 wt% aqueous ammonium persulfate solution.

8. The preparation method of a wind turbine blade protection coating according to claim 5, characterized in that, In the wind turbine blade protection coating, the mass ratio of the copolymer emulsion, 12 wt% aqueous polyurethane emulsion solution, polyhydroxyalkanoate - grafted sepiolite, composite anti - ultraviolet filler and antifoaming agent is (45 - 50):(45 - 50):(30 - 40):(10 - 20):0.

1.

9. The preparation method of a wind power blade protection coating according to claim 5, characterized in that, The antifoaming agent is a silicone resin antifoaming agent.

10. A wind power blade protection coating, characterized in that, It is prepared by the preparation method of the wind turbine blade protection coating according to any one of claims 1 - 9.

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