A swelling disintegration method for decomposing retired wind turbine blade fiber-resin

Abstract

The present application relates to the technical field of wind blade recycling, and specifically discloses a swelling and disintegration method for fiber-resin separation of retired wind blades, comprising the following steps: (1) cutting the waste wind blade into blocks, removing the surface coating and core material, and obtaining a fiber-reinforced thermosetting resin composite material; (2) testing the contact angle of different polar and / or non-polar liquids with the resin surface in the fiber-reinforced thermosetting resin composite material, and calculating the Hansen solubility parameter of the resin in the composite material according to the relationship among the contact angle, surface free energy and cohesive energy; (3) calculating the relative energy value between the resin and different polar aprotic solvents; and placing the composite material in the polar aprotic solvent with the lowest relative energy value to perform a swelling and degradation reaction. The method can maximize the integrity and mechanical properties of the fibers, and does not damage the molecular structure of the resin, so that the stability of the resin molecular structure can be maintained, and the recycled resin can be used with high value.

Description

Technical Field

[0001] This invention relates to the field of wind turbine blade recycling technology, specifically to a swelling and disintegration method for separating fibers and resins from decommissioned wind turbine blades. Background Technology

[0002] The information disclosed in this background section is intended only to enhance understanding of the overall background of the invention and is not necessarily to be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art.

[0003] In recent years, as early-installed wind turbines have gradually reached their designed service life (20-25 years), the efficient recycling of a large number of retired wind turbine blades has become increasingly prominent. It is estimated that by 2050, the total amount of retired wind turbine blades worldwide will reach 43 million tons, necessitating effective recycling and disposal solutions. Currently, the main reason for the difficulty in degrading retired wind turbine blades lies in their primary component material—fiber-reinforced thermosetting resin composites (hereinafter referred to as "composite materials"). The resin matrix in this material has a dense three-dimensional network structure and highly stable chemical bonds, hindering the efficient degradation of retired wind turbine blades.

[0004] Currently, the main methods for processing retired wind turbine blades include mechanical recycling, thermal recycling, and chemical recycling, as exemplified by the technologies used in patent applications CN202411226136.4, CN202211328617.7, CN202211299751.9, and CN202211299735.X. Mechanical recycling is relatively simple and low-cost, involving mechanically crushing and grinding the wind turbine blades into powder. However, this method cannot separate the resin from the fiber, and the damage to the fiber caused by crushing and grinding significantly reduces its value. Thermal recycling requires high-temperature and high-pressure conditions, resulting in enormous energy consumption. Furthermore, the thermal degradation of the resin produces harmful gases such as CO, nitrogen oxides, and sulfur oxides. These toxic products cause serious environmental and safety problems. Chemical recycling often uses strong acids, strong alkalis, or organic solvents as reaction media, facing the challenge of treating large amounts of waste liquid. Moreover, chemical recycling separates the resin in the composite material from the fiber by degrading it into low-molecular-weight products, making it difficult to recover the resin material itself. Therefore, there is an urgent need for a method for recycling decommissioned wind turbine blades that has mild reaction conditions, high product reuse value, and the ability to achieve non-destructive separation of fibers and resins. Summary of the Invention

[0005] Therefore, this invention proposes a swelling and disintegration method for separating fibers and resin in decommissioned wind turbine blades. This method acts only on the resin in the composite material, without corroding or oxidizing the fibers, thus maximizing the protection of the fiber's integrity and mechanical properties. Furthermore, it does not damage the resin's molecular structure, maintaining its stability and facilitating high-value recycling. Specifically, the technical solution of this invention is as follows.

[0006] A method for separating the fiber-resin in decommissioned wind turbine blades through swelling and disintegration includes the following steps: (1) After cutting the waste wind turbine blades into blocks, remove the surface coating and core material to obtain fiber-reinforced thermosetting resin composite material for later use.

[0007] (2) Test the contact angles between liquids of different polarities and / or non-polarities and the resin surface in the fiber-reinforced thermosetting resin composite material, and calculate the Hansen solubility parameter of the resin in the composite material based on the relationship between "contact angle - surface free energy - cohesive energy", including the dispersion component δ of the resin. d δ polar component p and hydrogen bond component δ h ,spare.

[0008] (3) Based on the Hansen solubility parameter, calculate the relative energy value (RED) between the resin and different polar aprotic solvents. Place the fiber-reinforced thermosetting resin composite material from step (1) in the polar aprotic solvent with the lowest RED for swelling and degradation reaction. After the reaction, separate the solid and liquid components, and dry them separately to obtain fiber and resin disintegration products, thus completing the degradation of the wind turbine blade.

[0009] Furthermore, in step (1), the fibers in the waste wind turbine blades include at least one of glass fiber, carbon fiber, etc.

[0010] Furthermore, in step (1), the resin in the waste wind turbine blades includes at least one of polyetheramine-cured epoxy resin, diethylenetriamine-cured epoxy resin, etc.

[0011] Further, in step (2), the polar liquid includes at least one of N,N-dimethylformamide, dimethyl sulfoxide ethylene glycol, ethyl acetate, acetone, ethanol, methanol, isopropanol, acetonitrile, and water.

[0012] Furthermore, in step (2), the non-polar liquid includes at least one of toluene, cyclohexane, benzene, etc.

[0013] Furthermore, in step (2), the relationship between the contact angle and the surface free energy in the relationship between "contact angle - surface free energy - cohesive energy" is as shown in equation (1): (1); Wherein: γ t,l γ is the total surface free energy of the polar and / or nonpolar liquids; d,l γ is the surface free energy dispersion component of the polar and / or nonpolar liquid; p,l γ is the polar component of the surface free energy of the polar and / or nonpolar liquids; d,s γ is the surface free energy dispersion component of the resin; p,s θ represents the polar component of the surface free energy of the resin; θ represents the contact angle.

[0014] Furthermore, in step (2), the relationship between surface free energy and cohesive energy in the relationship between "contact angle - surface free energy - cohesive energy" is shown in equations (2) to (4): (2); (3); (4); Where, δ d δ represents the dispersion component of the resin. p δ represents the polar component of the resin. h γ is the hydrogen bonding component of the resin. d,l γ is the dispersive surface free energy component of the resin. p,l The polar surface free energy component of the resin.

[0015] Further, in step (3), the polar aprotic solvent includes at least two of the following: 1-methyl-2-pyrrolidone, N,N-dimethylformamide, dimethyl sulfoxide, acetone, tetrahydrofuran, etc.

[0016] Furthermore, in step (3), the formula for calculating the relative energy value RED is shown in equations (5) and (6): (5); (6); Where, δ d δ is the dispersion component of the resin; p δ represents the polar component of the resin. h The hydrogen bonding component of the resin; δ d,l δ is the dispersive component of the polar aprotic solvent; p,l δ is the polar component of the polar aprotic solvent; h,l R0 is the hydrogen bonding component of the polar aprotic solvent; R0 is the radius of the Hansen solubility sphere at which the epoxy resin can swell.

[0017] Further, in step (3), the mass ratio of the fiber-reinforced thermosetting resin composite material to the polar aprotic solvent is 1:10~15.

[0018] Further, in step (3), the swelling degradation reaction is carried out at a temperature of 80-120°C for 6-12 hours. During the swelling degradation process, the solvent with strong affinity for the resin can quickly penetrate into the resin in the composite material and form a swollen layer on the surface. The solvent weakens the inter-chain forces by binding with the resin molecular chain segments through van der Waals forces and hydrogen bonds, causing the chain segments to change from coiling to stretching, thus reducing the strength of the resin. At the same time, the stretching of the molecular chain segments leads to the expansion of pores in the swollen layer, and microcracks are generated around the pores due to expansion stress. When the microcracks expand and connect, the swollen layer gradually disintegrates and peels off. After peeling, the solvent continues to penetrate into the resin and repeats the pore expansion and peeling process until the resin completely disintegrates into powder, ultimately achieving the separation of fibers and resin in the composite material.

[0019] Furthermore, in step (3), the drying temperature is 80~100℃ and the time is 10~12 hours.

[0020] Compared with the prior art, the present invention has at least the following beneficial technical effects: (1) The method proposed in this invention for calculating the Hansen solubility parameter of resin based on the "contact angle-surface free energy-cohesive energy relationship" can directly obtain the Hansen solubility parameter without dissolving the fiber-reinforced thermosetting resin composite material. This effectively solves the problem that traditional testing methods such as reverse gas chromatography are difficult to determine insoluble solids, resulting in the inability to obtain the Hansen solubility parameter. At the same time, this method can non-destructively measure the Hansen solubility parameter of the resin in the composite material, thereby maximizing the protection of the fiber integrity and mechanical properties, and will not damage the molecular structure of the resin, maintaining the stability of the resin molecular structure, and facilitating high-value utilization after recycling.

[0021] (2) The degradation method proposed in this invention can obtain a polar aprotic solvent that acts only on the resin in the composite material through a series of calculations. This solvent will not corrode or oxidize the fiber, but will only weaken the binding force between resin molecular chain segments and expand the internal pores of the resin, thereby achieving the disintegration of the resin and its separation from the fiber interface. This avoids damage to the molecular structure of the resin, thus maintaining the stability of the resin molecular structure and protecting the mechanical properties of the fiber to the greatest extent. This facilitates the high-value utilization of the fiber and resin disintegration products obtained after decomposition. In addition, the swelling disintegration method of this invention has a mild reaction, high decomposition efficiency, and is environmentally friendly, effectively reducing processing costs and energy consumption. Attached Figure Description

[0022] The accompanying drawings, which form part of this specification, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation thereof. Hereinafter, embodiments of the invention will be described in detail with reference to the accompanying drawings.

[0023] Figure 1 The image shows a fiber sample obtained in Example 1 below.

[0024] Figure 2 The image shown is a scanning electron microscope (SEM) image of the fiber obtained in Example 1 below.

[0025] Figure 3 The image shows a sample of resin disintegration products obtained in Example 1 below.

[0026] Figure 4 The following is an infrared comparison image of the resin disintegration products obtained in Example 1.

[0027] Figure 5 The image shows a fiber sample obtained in Example 2 below.

[0028] Figure 6 The image shown is a scanning electron microscope (SEM) image of the fiber obtained in Example 2 below.

[0029] Figure 7 The image shows a sample of resin disintegration products obtained in Example 2 below.

[0030] Figure 8 The following is an infrared comparison image of the resin disintegration products obtained in Example 2.

[0031] Figure 9 The image shows a fiber sample obtained in Example 3 below.

[0032] Figure 10 The image shown is a scanning electron microscope (SEM) image of the fiber obtained in Example 3 below.

[0033] Figure 11 The image shows a sample of resin disintegration products obtained in Example 3 below.

[0034] Figure 12 The following is an infrared comparison image of the resin disintegration products obtained in Example 3.

[0035] Figure 13 The image shows a fiber sample obtained in Example 4 below.

[0036] Figure 14 The image shown is a scanning electron microscope (SEM) image of the fiber obtained in Example 4 below.

[0037] Figure 15 The image shows a sample of resin disintegration products obtained in Example 4 below.

[0038] Figure 16 The following is an infrared comparison image of the resin disintegration products obtained in Example 4.

[0039] Figure 17 The image shows a fiber sample obtained in Example 5 below.

[0040] Figure 18 The image shown is a scanning electron microscope (SEM) image of the fiber obtained in Example 5 below.

[0041] Figure 19 The image shows a sample of resin disintegration products obtained in Example 5 below.

[0042] Figure 20 The following is an infrared comparison image of the resin disintegration products obtained in Example 5. Detailed Implementation

[0043] The present invention is further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Experimental methods in the following embodiments, unless otherwise specified, are generally performed under conventional conditions or as recommended by the manufacturer.

[0044] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of skill in the art. The reagents and raw materials used in this invention are readily available through conventional means, and unless otherwise specified, they shall be used in accordance with conventional methods in the art or as per the product instructions. Furthermore, any methods and materials similar to or equivalent to those described herein may be applied to the methods of this invention.

[0045] Example 1 A method for separating the fiber-resin in decommissioned wind turbine blades through swelling and disintegration includes the following steps: (1) Cut the waste wind turbine blades into blocks of length × width × height = 1.5 × 2 × 0.5 cm, and use an angle grinder to remove the surface coating and core material (such as PVC, balsa wood, etc.) to obtain fiber-reinforced thermosetting resin composite material for later use.

[0046] (2) Test the contact angle θ between different polar and / or non-polar liquids and the resin surface in the fiber-reinforced thermosetting resin composite material. For each liquid, test 5 droplets on the surface of the composite material, each droplet having a volume of 2µl. Measure the contact angle θ on the left and right sides of each droplet, and take the average of all measurements. Obtain the test results of the contact angle θ of each polar and non-polar liquid, as well as the total surface free energy γ of the polar and non-polar liquids. t,l Surface free energy dispersion component γ d,l Surface free energy polar component γ p,l As shown in Table 1 below.

[0047] Table 1

[0048] (3) Calculate the Hansen solubility parameter of the resin in the composite material based on the relationship between "contact angle - surface free energy - cohesive energy". Wherein: The relationship between the contact angle and the surface free energy is shown in equation (1): (1); In the above formula (1): γ t,l γ is the total surface free energy of the polar and / or nonpolar liquids; d,l γ is the surface free energy dispersion component of the polar and / or nonpolar liquid; p,l γ is the polar component of the surface free energy of the polar and / or nonpolar liquids; d,s γ is the surface free energy dispersion component of the resin; p,s θ represents the polar component of the surface free energy of the resin; θ represents the contact angle.

[0049] The relationship between the surface free energy and the cohesive energy is shown in equations (2) to (4): (2); (3); (4); In equations (2) to (4) above: δ d δ represents the dispersion component of the resin. p δ represents the polar component of the resin. h γ is the hydrogen bonding component of the resin. d,l γ is the dispersive surface free energy component of the resin. p,l Let δ be the polar surface free energy component of the resin. Substituting the test results from Table 1 into the above formula, the calculated result is: δ d =14.59MPa 0.5 δ p =7.6MPa 0.5 δ h =13.92MPa 0.5 This refers to the Hansen solubility parameter mentioned above, for future reference.

[0050] (4) Based on the Hansen solubility parameters obtained in the previous step, calculate the relative energy value RED between the resin and different polar aprotic solvents (including 1-methyl-2-pyrrolidone, N,N-dimethylformamide, and dimethyl sulfoxide), and the calculation formulas are shown in equations (5) and (6): (5); (6); Wherein, R0 is the radius of the Hansen solubility sphere when the epoxy resin reaches swelling, and its value is 14.04, δ d,l δ is the dispersive component of the polar aprotic solvent; p,l δ is the polar component of the polar aprotic solvent; h,l The hydrogen bonding component of the polar aprotic solvent is given. The dispersion component, polar component, and hydrogen bonding component are all physical properties of the solvent itself. The specific values ​​of the above parameters and the calculated relative energy values ​​RED are shown in Table 2.

[0051] Table 2

[0052] (4) From the above calculation results, it can be seen that the relative energy value RED between the resins in the polar aprotic solvent N,N-dimethylformamide is the lowest. Therefore, the fiber-reinforced thermosetting resin composite material of step (1) is placed in the polar aprotic solvent N,N-dimethylformamide (the mass ratio of the two is 1:10), and then heated to 120°C in an oil bath and allowed to stand for 3 hours. The composite material exhibits obvious stratification. Then, it is continuously stirred at a speed of 400 r / min for 3 hours to complete the swelling degradation reaction. The obtained reaction liquid is then filtered to separate the solid and liquid phases, and the liquid phase and solid product are obtained respectively. The solid product is washed with anhydrous ethanol and dried at 80°C for 12 hours to obtain fibers (such as... Figure 1 , Figure 2 (As shown). The liquid phase was dried at 80°C for 12 hours to obtain a powdered resin disintegration product (e.g. Figure 3 (As shown). Figure 4 The infrared comparison images of the resin disintegration products and the original resin (i.e., the resin in the discarded wind turbine blades) in this embodiment show that the method in this embodiment does not destroy the molecular structure of the resin, maintains the stability of the resin molecular structure, and helps to protect the integrity and mechanical properties of the fiber to the greatest extent. Meanwhile, from... Figure 2 As can be seen, the fiber surface maintains good structural integrity, indicating that the method of this embodiment achieves resin disintegration and separation from the fiber interface while avoiding damage to the molecular structure of the resin and the fiber surface.

[0053] Example 2 A swelling and disintegration method for separating fiber-resin in decommissioned wind turbine blades is similar to Example 1 above, except that: the fiber-reinforced thermosetting resin composite material is placed in a polar aprotic solvent N,N-dimethylformamide (mass ratio 1:12), then heated in an oil bath to 100°C and allowed to stand for 5 hours, resulting in obvious stratification of the composite material. The mixture is then continuously stirred at 400 r / min for 5 hours to complete the swelling and degradation reaction. The resulting reaction solution is then filtered for solid-liquid separation, yielding a liquid phase and a solid product. The solid product is washed with anhydrous ethanol and dried at 90°C for 11 hours to obtain the fiber (e.g., ...). Figure 5 , Figure 6 The liquid phase was dried at 90°C for 11 hours to obtain a powdered resin disintegration product (as shown). Figure 7 (As shown). Figure 8 The infrared comparison images of the resin disintegration products and the original resin in this embodiment show that the method in this embodiment does not destroy the molecular structure of the resin, maintains the stability of the resin molecular structure, and helps to maximize the protection of the fiber integrity and mechanical properties. Meanwhile, from... Figure 6 It can be seen that the fiber surface maintains good structural integrity.

[0054] Example 3 A swelling and disintegration method for separating fiber-resin in decommissioned wind turbine blades is similar to Example 1 above, except that: the fiber-reinforced thermosetting resin composite material is placed in a polar aprotic solvent N,N-dimethylformamide (mass ratio 1:15), then heated in an oil bath to 80°C and allowed to stand for 6 hours, resulting in obvious stratification of the composite material. The mixture is then continuously stirred at 400 r / min for 6 hours to complete the swelling and degradation reaction. The resulting reaction solution is then filtered for solid-liquid separation, yielding a liquid phase and a solid product. The solid product is washed with anhydrous ethanol and dried at 100°C for 10 hours to obtain the fiber (e.g., ...). Figure 9 , Figure 10 (As shown). The liquid phase was dried at 100°C for 10 hours to obtain a powdered resin disintegration product (e.g. Figure 11 (As shown). Figure 12 The infrared comparison images of the resin disintegration products and the original resin in this embodiment show that the method in this embodiment does not destroy the molecular structure of the resin, maintains the stability of the resin molecular structure, and helps to maximize the protection of the fiber integrity and mechanical properties. Meanwhile, from... Figure 10 It can be seen that the fiber surface maintains good structural integrity.

[0055] Example 4 A swelling and disintegration method for separating fiber-resin in decommissioned wind turbine blades, similar to Example 1 above, differs in that: the fiber-reinforced thermosetting resin composite material is placed in a polar aprotic solvent 1-methyl-2-pyrrolidone (mass ratio 1:10), then heated in an oil bath to 120°C and allowed to stand for 3 hours, resulting in obvious stratification of the composite material. The mixture is then continuously stirred at 400 r / min for 3 hours to complete the swelling and degradation reaction. The resulting reaction solution is then filtered for solid-liquid separation, yielding a liquid phase and a solid product. The solid product is washed with anhydrous ethanol and dried at 80°C for 12 hours to obtain the fiber (e.g., ...). Figure 13 , Figure 14 (As shown). The liquid phase was dried at 80°C for 12 hours to obtain a powdered resin disintegration product (e.g. Figure 15 (As shown). Figure 16 The infrared comparison images of the resin disintegration products and the original resin in this embodiment show that the method in this embodiment does not destroy the molecular structure of the resin, maintains the stability of the resin molecular structure, and helps to maximize the protection of the fiber integrity and mechanical properties. Meanwhile, from... Figure 14 It can be seen that the fiber surface maintains good structural integrity. In this embodiment, with the polar aprotic solvent having a higher relative energy (RED) than N,N-dimethylformamide, good swelling and disintegration effects were achieved by employing matched process parameters.

[0056] Example 5 A swelling and disintegration method for separating fiber-resin in decommissioned wind turbine blades, similar to Example 1 above, differs in that: the fiber-reinforced thermosetting resin composite material is placed in a polar aprotic solvent, dimethyl sulfoxide (mass ratio 1:10), then heated in an oil bath to 120°C and allowed to stand for 3 hours, resulting in obvious stratification of the composite material. The mixture is then continuously stirred at 400 r / min for 3 hours to complete the swelling and degradation reaction. The resulting reaction solution is then filtered for solid-liquid separation, yielding a liquid phase and a solid product. The solid product is washed with anhydrous ethanol and dried at 80°C for 12 hours to obtain the fiber (e.g., ...). Figure 17 , Figure 18 (As shown). The liquid phase was dried at 80°C for 12 hours to obtain a powdered resin disintegration product (e.g. Figure 19 (As shown). Figure 20 The infrared comparison images of the resin disintegration products and the original resin in this embodiment show that the method in this embodiment does not destroy the molecular structure of the resin, maintains the stability of the resin molecular structure, and helps to maximize the protection of the fiber integrity and mechanical properties. Meanwhile, from... Figure 18It can be seen that the fiber surface maintains good structural integrity. In this embodiment, with the polar aprotic solvent having a higher relative energy (RED) than N,N-dimethylformamide, good swelling and disintegration effects were achieved by employing matched process parameters.

[0057] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for the swelling and disintegration of fibers and resins in decommissioned wind turbine blades, characterized in that, Includes the following steps: (1) After cutting the waste wind turbine blades into blocks, the surface coating and core material are removed to obtain fiber-reinforced thermosetting resin composite material for later use; (2) Test the contact angles between liquids of different polarities and / or non-polarities and the resin surface in the fiber-reinforced thermosetting resin composite material, and calculate the Hansen solubility parameter of the resin in the composite material based on the relationship between "contact angle - surface free energy - cohesive energy", including the dispersion component δ of the resin. d δ polar component p and hydrogen bond component δ h ,spare; (3) Based on the Hansen solubility parameter, calculate the relative energy value (RED) between the resin and different polar aprotic solvents; place the fiber-reinforced thermosetting resin composite material from step (1) in the polar aprotic solvent with the lowest RED for swelling and degradation reaction; after the reaction, separate the solid and liquid, and dry them to obtain fiber and resin disintegration products, thus completing the degradation of the wind turbine blade.

2. The swelling and disintegration method for separating fiber-resin in decommissioned wind turbine blades according to claim 1, characterized in that, In step (1), the fibers in the waste wind turbine blades include at least one of glass fiber and carbon fiber.

3. The swelling and disintegration method for separating fiber-resin in decommissioned wind turbine blades according to claim 1, characterized in that, In step (1), the resin in the waste wind turbine blades includes at least one of polyetheramine-cured epoxy resin and diethylenetriamine-cured epoxy resin.

4. The swelling and disintegration method for separating fiber-resin in decommissioned wind turbine blades according to claim 1, characterized in that, In step (2), the polar liquid includes at least one of N,N-dimethylformamide, dimethyl sulfoxide ethylene glycol, ethyl acetate, acetone, ethanol, methanol, isopropanol, acetonitrile, and water. Alternatively, in step (2), the non-polar liquid includes at least one of toluene, cyclohexane, and benzene.

5. The swelling and disintegration method for separating fiber-resin in decommissioned wind turbine blades according to claim 1, characterized in that, In step (2), the relationship between contact angle and surface free energy in the relationship between "contact angle-surface free energy-cohesive energy" is shown in equation (1): （1）； Wherein: γ t,l γ is the total surface free energy of the polar and / or nonpolar liquids; d,l γ is the surface free energy dispersion component of the polar and / or nonpolar liquid; p,l γ is the polar component of the surface free energy of the polar and / or nonpolar liquids; d,s γ is the surface free energy dispersion component of the resin; p,s θ represents the polar component of the surface free energy of the resin; θ represents the contact angle.

6. The swelling and disintegration method for separating fiber-resin in decommissioned wind turbine blades according to claim 1, characterized in that, In step (2), the relationship between "contact angle - surface free energy - cohesive energy" is as shown in equations (2) to (4): （2）； （3）； （4）； Where, δ d δ represents the dispersion component of the resin. p δ represents the polar component of the resin. h γ is the hydrogen bonding component of the resin. d,l γ is the dispersive surface free energy component of the resin. p,l The polar surface free energy component of the resin.

7. The swelling and disintegration method for separating fiber-resin in decommissioned wind turbine blades according to claim 1, characterized in that, In step (3), the polar aprotic solvent includes at least two of the following: 1-methyl-2-pyrrolidone, N,N-dimethylformamide, dimethyl sulfoxide, acetone, and tetrahydrofuran.

8. The swelling and disintegration method for separating fiber-resin in decommissioned wind turbine blades according to claim 1, characterized in that, In step (3), the formulas for calculating the relative energy value RED are shown in equations (5) and (6): （5）； （6）； Where, δ d δ is the dispersion component of the resin; p δ represents the polar component of the resin. h δ represents the hydrogen bonding component of the resin. d,l δ is the dispersive component of the polar aprotic solvent; p,l δ is the polar component of the polar aprotic solvent; h,l R0 is the hydrogen bonding component of the polar aprotic solvent; R0 is the radius of the Hansen solubility sphere at which the epoxy resin can swell.

9. The swelling and disintegration method for separating fiber-resin in decommissioned wind turbine blades according to any one of claims 1-8, characterized in that, In step (3), the mass ratio of the fiber-reinforced thermosetting resin composite material to the polar aprotic solvent is 1:10~15.

10. The swelling and disintegration method for separating fiber-resin in decommissioned wind turbine blades according to any one of claims 1-8, characterized in that, In step (3), the temperature of the swelling degradation reaction is 80~120℃ and the time is 6~12 hours; or, in step (3), the drying temperature is 80~100℃ and the time is 10~12 hours.

Images