Plate for wind power blade as well as preparation method and application of plate

Abstract

The invention provides a plate for a wind power blade and a preparation method and application thereof, the preparation method comprises the following steps: (1) adding a first monomer and an initiator into a reactor, reacting until bubbles appear in a reaction liquid, and then quenching the reaction to obtain liquid resin; and (2) mixing the liquid resin obtained in the step (1) with a microcapsule type phase change material, defoaming, and then performing post-curing by adopting a vacuum infusion process (VARIM) to obtain the plate for the wind power blade. In a liquid resin post-curing system through a VARIM process, the microcapsule type phase change material is introduced to absorb heat released by a reaction in a liquid resin post-curing polymerization process, so that a gel effect in a polymerization reaction is avoided. The obtained plate for the wind power blade is uniform in texture, and has the mechanical property equivalent to that of the commercialized epoxy resin-based wind power blade at present.

Description

Technical Field

[0001] This invention belongs to the field of vacuum infusion technology, and relates to a plate material for wind turbine blades, its preparation method and application. Background Technology

[0002] Wind turbine blades are the core components of wind turbines, with a lifespan of approximately 20-25 years. Currently, commercially available wind turbine blades are composite materials made from thermosetting resins and fibrous fillers. The cross-linked structure of thermosetting resins prevents the recycling of solid waste from these blades, leading to their typical disposal through landfill or incineration after retirement, posing a significant environmental hazard. In contrast, thermoplastic resin products are biodegradable, reprocessable, and reusable, overcoming the shortcomings of thermosetting resins while offering advantages such as short molding cycles and weldability. Vigorously developing thermoplastic resin research and development to replace thermosetting resins is a crucial direction for the development of the wind power industry. Currently, domestically developed wind turbine blade resins are still primarily thermosetting epoxy resins. Therefore, there is an urgent need to develop technologies for room-temperature curing thermoplastic wind turbine blades to replace thermosetting wind turbine blades.

[0003] Acrylic monomers, such as methyl methacrylate (MMA), can polymerize and cure at room temperature under specific conditions to form polymethyl methacrylate (PMMA). PMMA and its monomer MMA are miscible, forming a PMMA-MMA reactive binary liquid resin with potential applications. Combining the excellent weather resistance, chemical corrosion resistance, superior optical properties, and relatively low density of acrylic resins, they hold promise for large-scale commercial application as a recyclable and reusable resin substrate for wind turbine blades. However, the MMA polymerization reaction is exothermic. During the free monomer polymerization process, the viscosity of MMA increases sharply with the increase of conversion rate, making heat dissipation difficult and leading to an auto-accelerated reaction (also known as the gel effect), resulting in rapid polymerization and degradation, making the reaction difficult to control. Vacuum infusion molding (VARIM) is a suitable technology for manufacturing large-size wind turbine blades. However, the gel effect during the post-curing process of PMMA-MMA binary liquid resin using the VARIM process will affect the mechanical properties of the blades.

[0004] Therefore, in this field, there is a desire to develop a method for preparing wind turbine blades using a vacuum infusion process, which avoids the gelation effect, resulting in rapid polymerization, degradation, etc. Summary of the Invention

[0005] In view of the shortcomings of the prior art, the purpose of this invention is to provide a plate for wind turbine blades, its preparation method and application.

[0006] To achieve this objective, the present invention adopts the following technical solution:

[0007] In a first aspect, the present invention provides a method for preparing a sheet metal for wind turbine blades, the method comprising the following steps:

[0008] (1) Add the first monomer and the initiator to the reactor and react until bubbles appear in the reaction liquid. Then quench the reaction to obtain liquid resin.

[0009] (2) The liquid resin obtained in step (1) is mixed with microcapsule-type phase change material, degassed, and then post-cured using vacuum infusion process (VARIM) to obtain the plate material for wind turbine blades.

[0010] This invention introduces a microencapsulated phase change material into the post-curing system of liquid resin using the VARIM process. This material absorbs the heat released during the polymerization reaction of the liquid resin during post-curing, thus avoiding the gel effect in the polymerization reaction. The resulting wind turbine blade sheet exhibits uniform texture and mechanical properties comparable to those of commercially available epoxy resin-based wind turbine blades.

[0011] The heat generated during the post-curing of liquid resin using the VARIM process causes the system temperature to rise, resulting in a gel effect. Introducing microencapsulated phase change materials into the liquid resin system allows the phase change materials to absorb the heat of polymerization generated by the system and undergo a phase transition, thereby maintaining the system temperature below the gel reaction temperature.

[0012] The process route of this invention is clear and feasible, simple to operate, requires few controllable conditions and is easy to implement, and can be used for large-scale mass production.

[0013] Preferably, the first monomer comprises methyl methacrylate (MMA).

[0014] Preferably, the initiator comprises any one or a combination of at least two of benzoyl peroxide (BPO), azobisisobutyronitrile (AIBN), and N,N-dimethylaniline (DMA).

[0015] Preferably, the shell material of the microcapsule-type phase change material has good compatibility with the liquid resin.

[0016] Preferably, the shell material of the microencapsulated phase change material includes, but is not limited to, organic materials such as melamine-formaldehyde resin (MF), polystyrene co-acrylate, acrylate-based polymers, high-density polyethylene (HDPE), polyurea, polyoxymethylene, polyurethane, gelatin, gum arabic, polydimethylsiloxane (PDMS), carbon-based materials (e.g., graphene), tetraethoxysilane (TEOS), methacryloyloxypropyltrimethoxysilane (MPS), etc.; inorganic materials such as zinc oxide (ZnO), iron(II,III) oxide (Fe3O4), silicon dioxide (SiO2), calcium carbonate, titanium dioxide (TiO2), metals, etc.; and can be prepared into double-shell or multi-shell microcapsules and composite microcapsules such as SiO2 / TiO2, SiO2 / Fe3O4, SiO2 / graphene, tetraethoxysilane (TEOS) / methacryloyloxypropyltrimethoxysilane (MPS), etc.

[0017] Preferably, the phase change temperature of the core material of the microcapsule-type phase change material is similar to the post-curing temperature in step (2).

[0018] Preferably, the core material of the microencapsulated phase change material includes any one or a combination of at least two of stearic acid, palmitic acid, paraffin, acetamide, sodium acetate trihydrate, and barium hydroxide octahydrate.

[0019] Preferably, the size of the microencapsulated phase change material is 50nm-100μm, such as 50nm, 100nm, 200nm, 300nm, 400nm, 500nm, 600nm, 700nm, 800nm, 900nm, 1μm, 3μm, 5μm, 8μm, 10μm, 20μm, 30μm, 40μm, 50μm, 60μm, 70μm, 80μm, 90μm, 100μm, etc.

[0020] Preferably, based on the total weight of the first monomer, initiator, and microencapsulated phase change material as 100%, the amount of the first monomer is 94-99.4%, for example, 94%, 94.5%, 95%, 95.5%, 96%, 96.5%, 97%, 97.5%, 98%, 98.5%, 99%, 99.4%, etc.; the amount of the initiator is 0.1-1%, for example, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, etc.; and the amount of the microencapsulated phase change material is 0.5-5%, for example, 0.5%, 0.8%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, etc.

[0021] Preferably, step (2) further includes a second monomer.

[0022] Preferably, the second monomer comprises any one or a combination of at least two of butyl methacrylate, butyl acrylate, and styrene.

[0023] Preferably, based on the total weight of the first monomer, the second monomer, the initiator, and the microencapsulated phase change material as 100%, the amount of the first monomer is 84-99.4%, for example, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, 99.4%, etc., and the amount of the second monomer is 0-10%, for example, 0.1%, 0.3%, 0.5%, 1%. The amounts of the initiator are 0.1-1%, such as 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, etc., and the amounts of the microencapsulated phase change material are 0.5-5%, such as 0.5%, 0.8%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, etc.

[0024] Preferably, the reaction temperature in step (1) is 70-100℃, such as 70℃, 75℃, 80℃, 85℃, 90℃, 95℃, 100℃, etc.

[0025] Preferably, the reaction in step (1) is carried out under a protective atmosphere.

[0026] Preferably, the protective atmosphere comprises nitrogen.

[0027] Preferably, the quenching of the reaction in step (1) specifically involves transferring the reactor to an ice bath to quench the reaction.

[0028] Preferably, the mixing in step (2) includes ultrasonic mixing;

[0029] Preferably, the ultrasonic mixing time is not less than 2 hours, for example, 2 hours, 2.5 hours, 3 hours, 3.5 hours, 4 hours, etc., until the mixture is uniform.

[0030] Preferably, the degassing time in step (2) is 20-40 min, such as 20 min, 25 min, 30 min, 35 min, 40 min, etc.

[0031] Preferably, the post-curing temperature in step (2) is room temperature.

[0032] Preferably, step (2) of the post-curing process using vacuum infusion technology further includes the step of adding reinforcing fibers.

[0033] Preferably, the reinforcing fibers comprise glass fibers and / or carbon fibers.

[0034] That is, the board obtained by the preparation method provided by the present invention can be a board without reinforcing fibers or a board containing reinforcing fibers, such as PMMA board, MMA and butyl methacrylate copolymer board, MMA and butyl acrylate copolymer board, glass fiber reinforced PMMA composite board, etc.

[0035] As a preferred embodiment of the present invention, the preparation method includes the following steps:

[0036] (1) Add the first monomer, optional second monomer and initiator to the reactor, reflux under a protective atmosphere, react at 70-100℃ until bubbles appear in the reaction liquid and the conversion rate reaches more than 10%, then quickly transfer the reactor to an ice bath to quench the reaction and obtain liquid resin.

[0037] (2) The liquid resin obtained in step (1) is ultrasonically mixed with the microcapsule-type phase change material, vacuum degassing for 20-40 minutes, and then post-cured at room temperature using a vacuum infusion process to obtain the plate material for wind turbine blades.

[0038] Alternatively, the liquid resin obtained in step (1) is ultrasonically mixed with the microcapsule-type phase change material, vacuum degassed for 20-40 minutes, and then vacuum infusion process is used to co-cure the degassed mixture with the reinforcing fiber at room temperature to obtain the plate material for wind turbine blades.

[0039] In a second aspect, the present invention provides a sheet material for wind turbine blades, which is prepared by the preparation method described in the first aspect.

[0040] Thirdly, the present invention provides an application of the sheet metal for wind turbine blades as described in the second aspect in wind power generation.

[0041] Compared with the prior art, the present invention has the following beneficial effects:

[0042] This invention introduces a microencapsulated phase change material into the post-curing system of liquid resin using the VARIM process. This material absorbs the heat released during the polymerization reaction of the liquid resin during post-curing, thus avoiding the gel effect in the polymerization reaction. The resulting wind turbine blade sheet exhibits uniform texture and mechanical properties comparable to those of commercially available epoxy resin-based wind turbine blades. Attached Figure Description

[0043] Figure 1 The image shows the appearance of a sample of the sheet metal for wind turbine blades provided in Example 1.

[0044] Figure 2The appearance of the sample of the sheet metal for wind turbine blades provided for Comparative Example 1. Detailed Implementation

[0045] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention.

[0046] Unless otherwise specified, the microcapsule-type phase change materials used in the embodiments and comparative examples of this invention are prepared by the following methods:

[0047] 1.6 g of surfactant cetyltrimethylammonium bromide (CTAB) was uniformly dispersed in a mixture of 70 ml ethanol and 140 ml deionized water to form a homogeneous aqueous phase. Separately, 10 g of paraffin, 6 g of TEOS, and 0.7 g of γ-methacryloyloxypropyltrimethoxysilane were mixed uniformly to form an oil phase. The above oil and water phases were then stirred at 10,000 rpm for 10 min to form a homogeneous oil-in-water (O / W) emulsion. 2.6 mL of ammonia water was then slowly added to the emulsion, and the mixture was mechanically stirred for 10 h. Finally, after vacuum filtration, washing several times with deionized water and ethanol, and thorough drying, the microcapsule-type phase change material was obtained.

[0048] Example 1

[0049] This embodiment provides a sheet metal for wind turbine blades, the preparation method of which includes the following steps:

[0050] (1) The first monomer (methyl methacrylate, 298.2g) and the initiator (azobisisobutyronitrile, 0.3g) were added to a three-necked flask and refluxed under nitrogen. The reaction was carried out at 70°C until bubbles appeared in the reaction liquid and the conversion rate reached more than 10%. Then the three-necked flask was quickly transferred to an ice bath to quench the reaction and obtain liquid resin.

[0051] (2) The liquid resin obtained in step (1) is ultrasonically mixed with microcapsule phase change material (1.5g) until the mixture is uniform, vacuum degassing for 30min, and then post-curing is carried out at room temperature using vacuum infusion process to obtain the plate material for wind turbine blades.

[0052] The sample appearance of the sheet metal for wind turbine blades provided in this embodiment is as follows: Figure 1 As shown, the sample has a uniform texture and no bubbles were generated during the solidification process, indicating that no burst polymerization occurred.

[0053] Example 2

[0054] This embodiment provides a sheet metal for wind turbine blades, the preparation method of which includes the following steps:

[0055] (1) The first monomer (methyl methacrylate, 294g) and the initiator (benzoyl peroxide, 2.1g; N,N-dimethylaniline, 0.9g) were added to a three-necked flask and refluxed under nitrogen atmosphere. The reaction was carried out at 80°C until bubbles appeared in the reaction liquid and the conversion rate reached more than 10%. Then the three-necked flask was quickly transferred to an ice bath to quench the reaction and obtain liquid resin.

[0056] (2) The liquid resin obtained in step (1) is ultrasonically mixed with microcapsule phase change material (3g) until the mixture is uniform, vacuum degassing for 30min, and then post-cured at room temperature using vacuum infusion process to obtain the plate material for wind turbine blades.

[0057] Example 3

[0058] This embodiment provides a sheet metal for wind turbine blades, the preparation method of which includes the following steps:

[0059] (1) The first monomer (methyl methacrylate, 264.3g), the second monomer (styrene, 29.4g), and the initiator (azobisisobutyronitrile, 0.3g) were added to a three-necked flask and refluxed under nitrogen atmosphere. The reaction was carried out at 90°C until bubbles appeared in the reaction liquid and the conversion rate reached more than 10%. Then the three-necked flask was quickly transferred to an ice bath to quench the reaction and obtain liquid resin.

[0060] (2) The liquid resin obtained in step (1) is ultrasonically mixed with microcapsule-type phase change material (6g) until the mixture is uniform, vacuum degassing for 30 minutes, and then post-curing is carried out at room temperature using a vacuum infusion process to obtain the plate material for wind turbine blades.

[0061] Example 4

[0062] This embodiment provides a sheet metal for wind turbine blades, the preparation method of which includes the following steps:

[0063] (1) The first monomer (methyl methacrylate, 255.2g), the second monomer (butyl methacrylate, 28.3g), and the initiator (benzoyl peroxide, 1.5g) were added to a three-necked flask and refluxed under nitrogen atmosphere. The reaction was carried out at 100°C until bubbles appeared in the reaction liquid and the conversion rate reached more than 10%. Then the three-necked flask was quickly transferred to an ice bath to quench the reaction and obtain liquid resin.

[0064] (2) The liquid resin obtained in step (1) is ultrasonically mixed with microcapsule phase change material (15g) until the mixture is uniform, vacuum degassing for 30min, and then post-curing is carried out at room temperature using vacuum infusion process to obtain the plate material for wind turbine blades.

[0065] Example 5

[0066] This embodiment provides a sheet metal for wind turbine blades, the preparation method of which includes the following steps:

[0067] (1) The first monomer (methyl methacrylate, 284.7g) and the initiator (benzoyl peroxide, 0.3g) were added to a three-necked flask and refluxed under nitrogen. The reaction was carried out at 70°C until bubbles appeared in the reaction liquid and the conversion rate reached more than 10%. Then the three-necked flask was quickly transferred to an ice bath to quench the reaction and obtain liquid resin.

[0068] (2) The liquid resin obtained in step (1) is ultrasonically mixed with microcapsule-type phase change material (15g) until the mixture is uniform, vacuum degassing for 30min, and then vacuum infusion process is used to co-cur with glass fiber (four layers of glass fiber cloth) at room temperature to obtain the plate material for wind turbine blades.

[0069] Example 6

[0070] The only difference between this embodiment and embodiment 1 is that the amount of microcapsule phase change material used in step (2) is 0.6g.

[0071] Example 7

[0072] The only difference between this embodiment and embodiment 1 is that the amount of microcapsule phase change material used in step (2) is 18g.

[0073] Comparative Example 1

[0074] The only difference between this comparative example and Example 1 is that microcapsule-type phase change material is not added in step (2).

[0075] The sample appearance of the sheet metal for wind turbine blades provided in this comparative example is as follows: Figure 2 As shown, the sample without microencapsulated phase change material underwent explosive polymerization during the curing process, making its performance undetectable.

[0076] The performance of the sheet metal for wind turbine blades provided in the embodiments and comparative examples was tested using the following methods:

[0077] (1) Tensile strength, tensile modulus and elongation at break: tested in accordance with GB / T1040.2-2006;

[0078] (2) Bending strength and bending modulus: Tested in accordance with GB / T9341-2008.

[0079] The performance test results are shown in Table 1.

[0080] Table 1

[0081]

[0082]

[0083] As can be seen from Table 1, the wind turbine blade plates provided in Examples 1-5 of the present invention all have mechanical properties comparable to those of currently commercialized epoxy resin-based wind turbine blades, and the preparation process does not exhibit a gel effect, which could lead to explosive polymerization.

[0084] Compared to Example 1, the wind turbine blade plate provided in Comparative Example 1 has a large number of bubbles. This is because Comparative Example 1 did not add microencapsulated phase change materials during the preparation process, which would cause a gel effect leading to explosive polymerization, making it impossible to test the mechanical properties of the final plate (e.g., ...). Figure 2 (As shown).

[0085] The applicant declares that the present invention is illustrated by the above embodiments to demonstrate the wind turbine blade plate, its preparation method, and its application. However, the present invention is not limited to the above embodiments, that is, it does not mean that the present invention must rely on the above embodiments to be implemented. Those skilled in the art should understand that any improvements to the present invention, equivalent substitutions of the raw materials used in the present invention, additions of auxiliary components, and selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A method for preparing a sheet metal for wind turbine blades, characterized in that, The preparation method includes the following steps: (1) Add the first monomer and the initiator to the reactor and react until bubbles appear in the reaction liquid. Then quench the reaction to obtain liquid resin. (2) The liquid resin obtained in step (1) is mixed with microcapsule phase change material, degassed, and then post-cured using a vacuum infusion process to obtain the plate material for wind turbine blades.

2. The preparation method according to claim 1, characterized in that, The first monomer includes methyl methacrylate; Preferably, the initiator includes any one or a combination of at least two of benzoyl peroxide, azobisisobutyronitrile, and N,N-dimethylaniline.

3. The preparation method according to claim 1 or 2, characterized in that, The shell material of the microencapsulated phase change material includes any one or a combination of at least two of the following: melamine-formaldehyde resin, polystyrene co-ethylene acrylate, acrylate-based polymers, high-density polyethylene, polyurea, polyoxymethylene, polyurethane, gelatin, gum arabic, polydimethylsiloxane, carbon-based materials, tetraethoxysilane, methacryloxypropyltrimethoxysilane, zinc oxide, iron tetroxide, silicon dioxide, calcium carbonate, titanium dioxide, and metals. Preferably, the core material of the microencapsulated phase change material includes any one or a combination of at least two of stearic acid, palmitic acid, paraffin, acetamide, sodium acetate trihydrate, and barium hydroxide octahydrate; Preferably, the size of the microcapsule-type phase change material is 50nm-100μm.

4. The preparation method according to any one of claims 1-3, characterized in that, Based on the total weight of the first monomer, initiator, and microencapsulated phase change material as 100%, the amount of the first monomer is 94-99.4%, the amount of the initiator is 0.1-1%, and the amount of the microencapsulated phase change material is 0.5-5%.

5. The preparation method according to any one of claims 1-4, characterized in that, Step (2) also includes a second monomer; Preferably, the second monomer comprises any one or a combination of at least two of butyl methacrylate, butyl acrylate, and styrene; Preferably, based on the total weight of the first monomer, the second monomer, the initiator, and the microencapsulated phase change material as 100%, the amount of the first monomer is 84-99.4%, the amount of the second monomer is 0-10%, the amount of the initiator is 0.1-1%, and the amount of the microencapsulated phase change material is 0.5-5%.

6. The preparation method according to any one of claims 1-5, characterized in that, The reaction temperature in step (1) is 70-100℃; Preferably, the reaction in step (1) is carried out under a protective atmosphere; Preferably, the protective atmosphere includes nitrogen; Preferably, the quenching of the reaction in step (1) specifically involves transferring the reactor to an ice bath to quench the reaction.

7. The preparation method according to any one of claims 1-6, characterized in that, The mixing in step (2) includes ultrasonic mixing; Preferably, the ultrasonic mixing time is not less than 2 hours; Preferably, the degassing time in step (2) is 20-40 min; Preferably, the post-curing temperature in step (2) is room temperature; Preferably, in step (2), the post-curing process using vacuum infusion technology further includes the step of adding reinforcing fibers; Preferably, the reinforcing fibers comprise glass fibers and / or carbon fibers.

8. The preparation method according to any one of claims 1-7, characterized in that, The preparation method includes the following steps: (1) Add the first monomer, optional second monomer and initiator to the reactor, reflux under a protective atmosphere, react at 70-100℃ until bubbles appear in the reaction liquid, and then transfer the reactor to an ice bath to quench the reaction to obtain liquid resin. (2) The liquid resin obtained in step (1) is ultrasonically mixed with the microcapsule-type phase change material, vacuum degassing for 20-40 minutes, and then post-cured at room temperature using a vacuum infusion process to obtain the plate material for wind turbine blades. Alternatively, the liquid resin obtained in step (1) is ultrasonically mixed with the microcapsule-type phase change material, vacuum degassed for 20-40 minutes, and then vacuum infusion process is used to co-cure the degassed mixture with the reinforcing fiber at room temperature to obtain the plate material for wind turbine blades.

9. A type of sheet metal for wind turbine blades, characterized in that, The sheet metal for wind turbine blades is prepared using the preparation method described in any one of claims 1-8.

10. The application of the sheet metal for wind turbine blades as described in claim 9 in wind power generation.

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