Epoxy-anhydride system composite material degradation solution, preparation method and application thereof
The degradation solution prepared by mixing zinc acetate and zinc acetylacetone hydrate with ethylene glycol completely degrades fiber-reinforced epoxy resin-based composite materials at high temperature using transesterification reaction, solving the problems of low degradation efficiency and high energy consumption in existing technologies, and achieving efficient and low-cost fiber recycling.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- CHUZHOU UNIV
- Filing Date
- 2023-06-19
- Publication Date
- 2026-05-19
AI Technical Summary
Existing technologies are unable to efficiently degrade fiber-reinforced epoxy resin-based composites, resulting in low recycling rates. Furthermore, traditional methods are energy-intensive, inefficient, and prone to damaging the fiber structure.
A degradation solution was prepared by mixing zinc acetate and zinc acetylacetone hydrate with ethylene glycol. The resin matrix in the composite material was completely degraded at high temperature through transesterification, and the fiber reinforcement was recovered.
A carbon fiber reinforced epoxy resin matrix composite material with epoxy-anhydride matrix was completely degraded within 16 h at 180℃, while maintaining the fiber properties well. The degradation rate was high, the energy consumption was low, and the cost was low.
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Figure CN116574305B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of composite material degradation technology, specifically relating to an epoxy-anhydride composite material degradation solution, its preparation method, and its application. Background Technology
[0002] Advanced composite material molding and high-end equipment manufacturing are important indicators of a nation's scientific and technological advancement, strategic emerging industries vigorously developed by the country, and the cornerstone of national weaponry development. Among these, fiber-reinforced epoxy resin-based composites are the most widely used advanced composite materials, characterized by high specific strength, high specific modulus, and good dimensional stability, playing a vital role in aerospace, sporting goods, and the automotive industry. However, the rapid development of the composite materials industry has also brought unavoidable problems: with the continuous increase in demand over the past few decades, many industries have generated a large amount of waste composite materials. Statistics show that if these waste composite materials are not recycled, by 2035, the aircraft industry will generate 23,000 tons / year of composite material waste, and by 2030, the wind power industry will generate 100,000 tons / year of decommissioned wind turbine blade waste. These waste materials will place a huge burden on the environment; the energy consumption for producing raw fibers is 183-286 MJ, 14 times higher than that for steel production; and the greenhouse gas emissions from carbon fiber manufacturing are 10 times that of steel manufacturing. Therefore, degrading composite materials and recycling fibers can not only solve environmental pollution problems but also generate significant economic value from the recycled fibers.
[0003] However, due to the three-dimensional cross-linked network structure of epoxy resin matrix, which exhibits insoluble and infusible properties, these composite materials are very difficult to degrade and recycle. The mechanical crushing method and high-temperature pyrolysis method commonly used in industry have many problems such as high energy consumption, low efficiency, and damage to fiber structure. At present, the global recycling rate of composite materials is less than 10%, and only 1% of carbon fiber is recycled and utilized. Summary of the Invention
[0004] The purpose of this invention is to prepare an efficient organic-inorganic degradation solution for epoxy-anhydride composite materials. A novel catalyst, zinc acetate or zinc acetylacetone hydrate, is discovered and dissolved alone in ethylene glycol, or a mixture of both dissolved in ethylene glycol, to prepare the degradation solution. This degradation solution is specifically designed for carbon fiber reinforced epoxy resin composites with an epoxy-anhydride matrix. The material to be degraded or recycled is placed in the degradation solution and reacted at 175-190°C for 12-16 hours to completely degrade the resin in the composite material. This invention primarily utilizes the transesterification reaction between the degradation solution and the resin matrix in the composite material, resulting in complete degradation of the resin matrix. Finally, the remaining fibers after complete degradation are washed three times in acetone and dried to obtain the fiber reinforcement in the composite material. The practical effects of this invention are as follows:Figure 1 As shown, where Figure 1 The resin material is TDE-85 epoxy resin cured with methylhexahydrophthalic anhydride as a curing agent. The composite material is T300 carbon fiber cloth and TDE-85 epoxy resin cured with methylhexahydrophthalic anhydride and 1,2,3,6-tetrahydrophthalic anhydride (molar ratio 1:1). The TDE-85 epoxy resin matrix is provided by Anhui Zhongbo New Materials Co., Ltd.
[0005] The preparation process of the degradation solution described in this invention is as follows:
[0006] Dissolve zinc acetate or zinc acetylacetonate hydrate in water, and then add ethylene glycol dropwise to the dissolved mixture; stir the above mixture at 110~130℃ to obtain a milky white suspension; let the above milky white suspension stand at room temperature to obtain the degradation solution.
[0007] The final concentration of zinc acetate is 0.0185~0.074 mol / L, and the final concentration of zinc acetylacetone hydrate is 0.0185~0.074 mol / L.
[0008] The stirring time is 10-25 min and the stirring speed is 150-300 r / min.
[0009] The settling time is 0.5 to 5 hours.
[0010] The degradation solution described in this invention is used as follows:
[0011] (1) The prepared carbon fiber reinforced epoxy resin matrix composite material or pure resin is completely immersed in the degradation solution. This can be done in a beaker or a reaction vessel. The container is sealed to prevent the degradation solution from evaporating during the degradation process. If there is a serious evaporation phenomenon in the degradation solution during the degradation process, the degradation solution can be added until the material is completely immersed.
[0012] (2) Place the above degradation container in an oven at 180°C and remove it after a certain degradation time. The degradation time can be determined according to the actual situation, generally 4 h, 8 h, 12 h, or 16 h.
[0013] (3) Take out the completely degraded fiber, wash it three times in acetone, and dry it at 40~50℃ to obtain the recycled fiber. Beneficial effects
[0014] This invention prepares an organic-inorganic degradation solution for the efficient degradation of epoxy-anhydride composite materials by mixing zinc acetate and zinc acetylacetone hydrate, two substances with completely different properties and solubility characteristics. After mixing, the solution enables the complete degradation of carbon fiber reinforced epoxy resin matrix composites based on epoxy-anhydride within 16 hours at 180°C. In contrast, the degradation rate of zinc acetate and zinc acetylacetone hydrate alone in the degradation of epoxy-anhydride matrix carbon fiber reinforced epoxy resin matrix composites is very low after 20 hours. However, when they are combined and prepared into a suspension, they can rapidly degrade epoxy-anhydride matrix carbon fiber reinforced epoxy resin matrix composites, thereby achieving efficient recovery of fibers from the composite material.
[0015] The degradation mechanism of the fiber-reinforced resin matrix composite material with epoxy-anhydride matrix in this invention is as follows: (1) Zinc acetate or zinc acetylacetonate hydrate is dissolved in water, and then ethylene glycol is added dropwise and mixed evenly to obtain a degradation solution; (2) During the degradation process, the mixed degradation solution swells and enters the polymer matrix network; (3) Under the action of the catalyst, the ester bonds in the polymer matrix (epoxy-anhydride crosslinking network) undergo transesterification reaction with the hydroxyl groups of ethylene glycol, thereby breaking the ester bonds in the crosslinking network and forming a new structure with ethylene glycol, thus achieving the degradation of the crosslinking network; (4) The degraded small molecule fragments dissolve in ethylene glycol, and the fiber can be obtained directly by filtration.
[0016] The degradation solution and its supporting degradation method described in this invention have the characteristics of low cost, wide applicability, convenient use, low degradation energy consumption, and no damage to fiber properties. Attached Figure Description
[0017] Figure 1 : Actual effect diagram of the application of this invention. Implementation
[0018] In the examples, zinc acetate, zinc acetylacetone hydrate, and ethylene glycol were all purchased from Beijing Innocare Reagent Co., Ltd. The degradable materials targeted were fiber-reinforced resin matrix composites and pure resin materials, specifically carbon fiber reinforced resin matrix composites based on an epoxy-anhydride system. The epoxy resin matrix used to prepare this composite material was provided by Anhui Zhongbo New Materials Co., Ltd.
[0019] In this invention, the preparation method of the carbon fiber reinforced epoxy resin matrix composite material of the epoxy-anhydride system used in the examples and comparative examples is as follows:
[0020] Using scissors, cut the T300 carbon fiber cloth into four pieces measuring 100 mm * 80 mm. Measure 10.04 g of TDE-85 resin using an electronic balance and place it in a small beaker. Heat the beaker in an oil bath at an initial temperature of 120°C. Weigh 4.52 g of methylhexahydrophthalic anhydride (MHHPA) and 5.04 g of 1,2,3,6-tetrahydrophthalic anhydride (TMMA) using weighing paper. Add these to the TDE-85 resin in batches, stirring with a magnetic stirrer until MHHPA and TMMA are fully dissolved, resulting in a pale yellow homogeneous solution. A small amount of white filamentous solid is produced during stirring. This solidifies into a white solid after the solution is removed from the heat source and returns to its original state upon reheating. Evenly coat the treated carbon fiber surface with the resin solution, impregnating each of the four carbon fiber pieces layer by layer. Finally, place the mixture into a mold. After preheating the flat vulcanizing apparatus to an initial temperature of 130℃ for 30 minutes, a stainless steel flat mold with dimensions of 100 mm long, 80 mm wide, and 1 mm thick, fitted with release paper, is placed on the apparatus for preheating. The mixed liquid and solid are transferred into the mold, and the apparatus is started to apply pressure and heat for curing. The curing process is as follows: 10 MPa pressure, 130℃ / 1 h, 150℃ / 2 h, 180℃ / 1 h. After curing, the mixture is cooled and demolded to obtain a black solid sheet with a relatively brittle and hard texture. Example
[0021] This embodiment provides an inorganic degradation solution, which is an ethylene glycol solution of zinc acetate, with a final concentration of 0.074 mol / L. The specific preparation method is as follows:
[0022] Dissolve 0.4075 g (0.0022 mol) of zinc acetate in 10 mL of deionized water, and then place the solution in a beaker containing 30 mL of ethylene glycol.
[0023] The above mixture was stirred at 120°C for 15 min at a stirring speed of 200 r / min to obtain a milky white solution.
[0024] The above milky white solution was left to stand at room temperature for 1 hour to obtain the degradation solution.
[0025] The degradation solution is used to degrade epoxy-anhydride composite materials, which are carbon fiber reinforced resin matrix composite materials based on epoxy-anhydride systems. The specific degradation method is as follows.
[0026] Pour 30 mL of the above degradation solution into a beaker, then cut the epoxy-anhydride composite material into 0.5 cm*0.5 cm*0.1 cm pieces, accurately weigh them, and then completely immerse them in the degradation solution. Seal the beaker to prevent the degradation solution from evaporating during the degradation process.
[0027] The beaker containing the degradation solution and composite material was placed in an oven at 180°C and the degradation was stopped and removed after reaching constant weight.
[0028] The carbon fibers obtained after complete degradation were washed three times in acetone and dried in an oven at 40°C for 2 hours to obtain the recycled carbon fibers.
[0029] Example 1: Degradation rate of carbon fiber reinforced resin matrix composites in epoxy-anhydride system at different degradation times
[0030] Degradation time Original sample mass / g Degradation mass / g Degradation rate (mass after degradation / original mass) 4 h 0.0402 0.0411 102.24 % 8 h 0.0422 0.0429 101.67 % 12 h 0.0400 0.0405 101.25 % 16 h 0.0412 0.0408 99.03 % 20.5 h 0.0412 0.0402 97.57 %
[0031] As can be seen from the above results, the inorganic degradation solution provided in this embodiment has a very slow degradation rate, and the degradation rate is very low after 20.5 h. Example
[0032] This embodiment provides an organic degradation solution for degrading epoxy-anhydride composite materials. The organic degradation solution is an ethylene glycol solution of zinc acetylacetone hydrate, wherein the final concentration of zinc acetylacetone hydrate is 0.074 mol / L. The specific preparation method is as follows:
[0033] Dissolve 0.585 g (0.0022 mol) of zinc acetylacetonate hydrate in 10 mL of deionized water, and then place the solution in a beaker containing 30 mL of ethylene glycol.
[0034] The above mixture was stirred at 120°C for 15 min at a stirring speed of 200 r / min to obtain a milky white suspension.
[0035] The above milky white suspension was allowed to stand at room temperature for 1 h to obtain the organic degradation solution.
[0036] The degradation solution is used to degrade epoxy-anhydride composite materials, which are carbon fiber reinforced resin matrix composite materials based on epoxy-anhydride systems. The specific degradation method is as follows.
[0037] Pour 30 mL of the above degradation solution into a beaker, then cut the epoxy-anhydride composite material into 0.5 cm*0.5 cm*0.1 cm pieces, accurately weigh them, and then completely immerse them in the degradation solution. Seal the beaker to prevent the degradation solution from evaporating during the degradation process.
[0038] The beaker containing the degradation solution and composite material was placed in an oven at 180°C and the degradation was stopped and removed after reaching constant weight.
[0039] The carbon fibers obtained after complete degradation were washed three times in acetone and dried in an oven at 40°C for 2 hours to obtain the recycled carbon fibers.
[0040] Example 2: Degradation rate of carbon fiber reinforced resin matrix composites in epoxy-anhydride system at different degradation times
[0041] Degradation time Original sample mass / g Degradation mass / g Degradation rate (mass after degradation / original mass) 4 h 0.0416 0.0433 104.09 % 8 h 0.0416 0.0424 101.92 % 12 h 0.0396 0.0403 101.77 % 16 h 0.0405 0.0390 96.30 % 20.5 h 0.0405 0.0378 93.33 %
[0042] As can be seen from the above results, the organic degradation solution provided in this embodiment has a very slow degradation rate, and the degradation rate is very low after 20.5 h. Example
[0043] This embodiment provides an organic-inorganic degradation solution for the efficient degradation of epoxy-anhydride composite materials. The degradation solution is an ethylene glycol solution of zinc acetate and zinc acetylacetone hydrate, wherein the final concentration of zinc acetate and zinc acetylacetone hydrate is 0.0185 mol / L. The specific preparation method is as follows:
[0044] Dissolve 0.1025 g (0.0006 mol) of zinc acetate and 0.1475 g (0.0006 mol) of zinc acetylacetonate hydrate in 10 mL of deionized water, and then place the solution in a beaker containing 30 mL of ethylene glycol.
[0045] The above mixture was stirred at 130°C for 10 min at a stirring speed of 200 r / min to obtain a milky white suspension.
[0046] The above-mentioned milky white suspension was allowed to stand at room temperature for 0.5 h to obtain the degradation solution.
[0047] The degradation solution is used to efficiently degrade epoxy-anhydride composite materials, which are carbon fiber reinforced resin matrix composite materials based on the epoxy-anhydride system. The specific degradation method is as follows.
[0048] Pour 30 mL of the above degradation solution into a beaker, then cut the epoxy-anhydride composite material into 0.5 cm*0.5 cm*0.1 cm pieces, accurately weigh them, and then completely immerse them in the degradation solution. Seal the beaker to prevent the degradation solution from evaporating during the degradation process.
[0049] The beaker containing the degradation solution and composite material was placed in a 175°C oven and allowed to degrade to a constant weight before being removed.
[0050] The carbon fibers obtained after complete degradation were washed three times in acetone and dried in an oven at 40°C for 2 hours to obtain the recycled carbon fibers.
[0051] Example 3: Degradation rate of carbon fiber reinforced resin matrix composites in epoxy-anhydride system at different degradation times
[0052] Degradation time Original sample mass / g Degradation mass / g Degradation rate (mass after degradation / original mass) 4 h 0.0398 0.0408 102.51 % 8 h 0.0430 0.0426 99.07 % 12 h 0.0376 0.0368 97.87 % 16 h 0.0386 0.0369 95.60 % 20.5 h 0.0386 0.0299 77.46 %
[0053] As can be seen from the above results, the degradation rate of the organic-inorganic mixed degradation solution provided in this embodiment is significantly improved compared with that of Examples 1 and 2 after 20.5 h. Example
[0054] This embodiment provides an organic-inorganic degradation solution for the efficient degradation of epoxy-anhydride composite materials. The degradation solution is an ethylene glycol solution of zinc acetate and zinc acetylacetone hydrate, wherein the final concentration of zinc acetate and zinc acetylacetone hydrate is 0.037 mol / L. The specific preparation method is as follows:
[0055] Dissolve 0.205 g (0.00011 mol) of zinc acetate and 0.295 g (0.00011 mol) of zinc acetylacetonate hydrate in 10 mL of deionized water, and then place the solution in a beaker containing 30 mL of ethylene glycol.
[0056] The above mixture was stirred at 140°C for 25 min at a stirring speed of 150 r / min to obtain a milky white suspension.
[0057] The above milky white suspension was allowed to stand at room temperature for 1 h to obtain the degradation solution.
[0058] The degradation solution is used to efficiently degrade epoxy-anhydride composite materials, which are carbon fiber reinforced resin matrix composite materials based on the epoxy-anhydride system. The specific degradation method is as follows.
[0059] Pour 30 mL of the above degradation solution into a beaker, then cut the epoxy-anhydride composite material into 0.5 cm*0.5 cm*0.1 cm pieces, accurately weigh them, and completely immerse them in the degradation solution. Seal the beaker to prevent the degradation solution from evaporating during the degradation process.
[0060] The beaker containing the degradation solution and composite material was placed in an oven at 180°C and the degradation was stopped and removed after reaching constant weight.
[0061] The carbon fibers obtained after complete degradation were washed three times in acetone and dried in an oven at 40°C for 2 hours to obtain the recycled carbon fibers.
[0062] Example 4: Degradation rate of carbon fiber reinforced resin matrix composites in epoxy-anhydride system at different degradation times
[0063] Degradation time Original sample mass / g Degradation mass / g Degradation rate (mass after degradation / original mass) 4 h 0.0367 0.0378 103.00 % 8 h 0.0391 0.0387 98.98 % 12 h 0.0432 0.0398 92.13 % 16 h 0.0418 0.0365 87.32 % 20.5 h 0.0418 0.0286 68.42 %
[0064] As can be seen from the above results, the degradation rate of the organic-inorganic mixed degradation solution provided in this embodiment is significantly improved compared with that of Examples 1, 2, and 3 after 20.5 h. Example
[0065] This embodiment provides an organic-inorganic degradation solution for the efficient degradation of epoxy-anhydride composite materials. The degradation solution is an ethylene glycol solution of zinc acetate and zinc acetylacetone hydrate, wherein the final concentration of zinc acetate and zinc acetylacetone hydrate is 0.074 mol / L. The specific preparation method is as follows:
[0066] Dissolve 0.4075 g (0.0022 mol) of zinc acetate hydrate and 0.585 g (0.0022 mol) of zinc acetylacetone hydrate in 10 mL of deionized water, and then place the solution in a beaker containing 30 mL of ethylene glycol.
[0067] The above mixture was stirred at 120°C for 15 min at a stirring speed of 300 r / min to obtain a milky white suspension.
[0068] The above milky white suspension was left to stand at room temperature for 5 h to obtain the degradation solution.
[0069] The degradation solution is used to efficiently degrade epoxy-anhydride composite materials. The specific degradation method for the epoxy-anhydride system is as follows.
[0070] Pour 30 mL of the above degradation solution into a beaker, then cut the epoxy-anhydride composite material into 0.5 cm*0.5 cm*0.1 cm pieces, accurately weigh them, and then completely immerse them in the degradation solution. Seal the beaker to prevent the degradation solution from evaporating during the degradation process.
[0071] The beaker containing the degradation solution and composite material was placed in a 190°C oven and allowed to degrade to a constant weight before being removed.
[0072] The carbon fibers obtained after complete degradation were washed three times in acetone and dried in an oven at 40°C for 3 hours to obtain the recycled carbon fibers.
[0073] Example 5 Degradation rate at different degradation times
[0074] Degradation time Original sample mass / g Degradation mass / g Degradation rate (mass after degradation / original mass) 4 h 0.0388 0.0390 100.52 % 8 h 0.0404 0.0388 96.04 % 12 h 0.0437 0.0399 91.30 % 16 h 0.0433 0.0367 84.76 % 19 h 0.0433 0.0296 68.36 %
[0075] As can be seen from the above results, the degradation rate of the organic-inorganic mixed degradation solution provided in this embodiment is higher than that of Examples 1, 2, and 3. Example
[0076] The ethylene glycol solutions of zinc acetate and zinc acetylacetone hydrate, both prepared in Example 5, with a final concentration of 0.037 mol / L, were used to degrade the pure resin matrix of the epoxy-anhydride system. The preparation method of the pure resin matrix of the epoxy-anhydride system is as follows:
[0077] 10.34 g of TDE-85 resin was measured using an electronic balance and placed in a small beaker. An oil bath was used for heating, with an initial temperature set to 100℃. 9.27 g of methylhexahydrophthalic anhydride (MHHPA) was weighed using weighing paper and added to the TDE-85 resin in batches, with magnetic stirring throughout until MHHPA was fully dissolved. The temperature was then raised to 130℃ within 30 minutes, yielding a pale yellow homogeneous solution. A small amount of white filamentous solid was produced during stirring; this solidified into a white solid after the solution was removed from the heat source and returned to its original state upon reheating. The flat vulcanizing apparatus was started and preheated to 130℃ for 30 minutes. A stainless steel flat mold with release paper (100 mm long, 80 mm wide, and 1 mm thick) was placed on the flat vulcanizing apparatus for preheating. The mixed liquid was transferred into a mold, and the flat vulcanizing apparatus was started to apply pressure and heat for curing. The curing process was 10 MPa pressure, 130℃ / 1 h, 150℃ / 2 h, and 180℃ / 1 h. After curing, the mixture was cooled and demolded to obtain a light yellow, transparent sheet with a relatively brittle and hard texture.
[0078] Pour 30 mL of the above degradation solution into a beaker, then accurately weigh the pure resin matrix of the epoxy-anhydride system and completely immerse it in the degradation solution. Seal the beaker to prevent the degradation solution from evaporating during the degradation process. Place the beaker in an oven at 175~190℃ and degrade to constant weight.
[0079] The degradation solution can also rapidly degrade epoxy-anhydride resin systems. Experiments showed that when 0.0205 g of pure epoxy-anhydride resin matrix was added to 30 mL of the degradation solution, after 12 h, only 0.0043 g of pure epoxy-anhydride resin matrix remained, representing a degradation of 78.90%. Constant weight was achieved in approximately 16 h, meaning that complete degradation of the pure epoxy-anhydride resin matrix requires 16 h. Example
[0080] The organic-inorganic degradation solutions prepared in Examples 2-5 yielded milky white suspensions. These suspensions were unstable during the degradation process, and white powder remained on the surface of the degraded material after retrieval. Therefore, an organic-inorganic degradation solution that can be stably stored for 7 days is provided. The preparation method of this organic-inorganic degradation solution is as follows:
[0081] The degradation solution is an ethylene glycol solution of zinc acetate and zinc acetylacetone hydrate, wherein the final concentration of zinc acetate is 0.037 mol / L and the final concentration of zinc acetylacetone hydrate is 0.037 mol / L. The specific preparation method is as follows:
[0082] Dissolve 0.205 g (0.00011 mol) of zinc acetate and 0.295 g (0.00011 mol) of zinc acetylacetonate hydrate in 10 mL of deionized water, and then place the solution in a beaker containing 30 mL of ethylene glycol.
[0083] Add 0.0359 g (0.0001 mol) of glyceryl monostearate to the beaker prepared in step ①.
[0084] The mixture obtained in step ② was stirred at 120°C for 25 min at a stirring speed of 150 r / min to obtain a milky white suspension.
[0085] The above milky white suspension was allowed to stand at room temperature for 1 h to obtain the degradation solution.
[0086] Tests showed that the degradation solution without added glyceryl monostearate would separate into layers and precipitate after about 5 hours, while the mixed suspension with added glyceryl monostearate could remain without separation or precipitation for 7 days.
[0087] Experiments showed that glyceryl monostearate at concentrations of 0.001–0.005 mol / L could maintain its stratification or precipitation for 7 days.
[0088] In this embodiment, ethylene glycol was purchased from Beijing Innocare Reagent Co., Ltd. The target degradation material is an epoxy-anhydride composite material, and the epoxy resin matrix used to prepare this composite material was provided by Anhui Zhongbo New Materials Co., Ltd.
[0089] Pour 30 mL of ethylene glycol into a beaker, then completely immerse the epoxy-anhydride composite material (carbon fiber reinforced composite material, 8 g) in the degradation solution, and seal the beaker to prevent the degradation solution from evaporating during the degradation process.
[0090] The beaker containing the degradation solution and composite material was placed in an oven at 180°C and removed after 10 hours of degradation.
[0091] This embodiment cannot degrade the pure resin matrix of the epoxy-anhydride system or the epoxy-anhydride composite material.
[0092] As can be seen from the performance tests of Examples 1-6 and the comparative examples, the degradation solution described in this invention can achieve complete degradation of the resin matrix and fiber recovery within 16 hours at 180°C, and the properties of the recovered fiber are close to those of the original fiber.
Claims
1. A degradation solution for epoxy-anhydride composite materials, characterized in that: The degradation solution is an ethylene glycol mixed suspension of zinc acetate and zinc acetylacetone hydrate; the final concentration of zinc acetate is 0.0185~0.074 mol / L, and the final concentration of zinc acetylacetone hydrate is 0.0185~0.074 mol / L.
2. The epoxy-anhydride composite material degradation solution according to claim 1, characterized in that: The epoxy-anhydride composite material degradation solution also includes glyceryl monostearate, with an addition amount of 0.001~0.005 mol / L.
3. A method for preparing the epoxy-anhydride composite material degradation solution according to claim 1, characterized in that: The preparation method of the degradation solution includes the following steps: dissolving zinc acetate and zinc acetylacetonate hydrate in deionized water to obtain a mixed solution, then placing the mixed solution in ethylene glycol and stirring at 120~140℃ to obtain a milky white suspension, which is then allowed to stand to obtain the degradation solution.
4. The method for preparing the epoxy-anhydride composite material degradation solution according to claim 3, characterized in that: The final concentration of zinc acetate is 0.0185~0.074 mol / L, and the final concentration of zinc acetylacetone hydrate is 0.0185~0.074 mol / L.
5. The method for preparing the epoxy-anhydride composite material degradation solution according to claim 3, characterized in that: After placing the mixed solution in ethylene glycol, the method further includes adding 0.001~0.005 mol / L of glyceryl monostearate.
6. The method for preparing the epoxy-anhydride composite material degradation solution according to claim 3, characterized in that: The stirring time for the stirring process is 10-25 min, and the stirring speed is 150-300 r / min.
7. The method for preparing the epoxy-anhydride composite material degradation solution according to claim 3, characterized in that: The settling time is 0.5 to 5 hours.
8. The application of the epoxy-anhydride composite material degradation solution according to claim 1, characterized in that: The degradation solution is used to degrade pure resin in the epoxy-anhydride system at a temperature of 175~190℃.
9. The application of the epoxy-anhydride composite material degradation solution according to claim 1, characterized in that: The degradation solution is used in carbon fiber reinforced epoxy resin matrix composites of epoxy-anhydride system, with a degradation temperature of 175~190℃.