Degradable epoxy resin composite material as well as preparation method and degradation method thereof

Abstract

The invention provides a degradable epoxy resin composite material as well as a preparation method and a degradation method thereof, and belongs to the technical field of epoxy resin composite material recovery. The epoxy resin composite material is prepared from a modified epoxy resin prepolymer, a curing agent and a fiber reinforced material, and the preparation method of the modified epoxy resin prepolymer comprises the following steps: reacting the epoxy resin prepolymer with a modifier to prepare the modified epoxy resin prepolymer. The degradable epoxy resin composite material, the supported Ni-Co-Pd / CeO2 catalyst and a solvent are mixed, hydrogen is introduced for reaction, and degradation treatment of the epoxy resin composite material is achieved. Beta-hydroxy ether is introduced by using a modifier, and in the presence of a supported Ni-Co-Pd / CeO2 catalyst, a C-O bond in epoxy resin is efficiently broken under the synergistic effect of the three metals, so that the epoxy resin composite material is convenient to degrade and recycle phenolic monomers, and the catalyst can be recycled.

Description

Technical Field

[0001] The present invention relates to the technical field of epoxy resin composite material recycling, and particularly to a degradable epoxy resin composite material, a preparation method thereof, and a degradation method thereof. Background Art

[0002] With the continuous growth of the demand for lightweight and high-strength composite materials, traditional epoxy resin-based composite materials have been widely used in the fields of aerospace, wind turbine blades, automobile manufacturing, electronic circuit boards, etc. However, these epoxy resin-based composite materials often belong to thermosetting materials. Once cured to form a crosslinked network, it is difficult to be processed by traditional thermoplastic plastic recycling means (such as simple melt re-molding). The resulting accumulation of waste epoxy composite materials not only causes waste of resources but also brings environmental pressure.

[0003] In recent years, in order to realize the resource recycling of epoxy resin materials, methods such as acid-base dissolution, pyrolysis, oxidative decomposition, catalytic hydrodepolymerization, etc. have been studied and explored. However, the above methods either require high temperature and high pressure (pyrolysis, gasification, etc.) with excessive energy consumption, or require a large amount of acids and bases, bringing subsequent treatment burdens, or cannot recover high-value organic monomers (such as bisphenol A, bisphenol S, etc.) and reinforcing fibers at the same time. In addition, even some catalytic hydrodepolymerization methods can recover phenolic monomers in the resin under relatively mild conditions, but they also face problems such as difficult catalyst recovery, poor reusability, and insufficient adaptability to different curing systems of epoxy resins, making it difficult to be widely promoted on a large scale.

[0004] Based on this, it is of great significance to study an innovative technical route: on the one hand, moderately modify the chemical structure of epoxy resin so that it has controllable degradation characteristics while maintaining mechanical properties; on the other hand, adopt an efficient and reusable catalytic system to realize the controllable depolymerization or degradation of epoxy resin under relatively mild conditions, so as to recover phenolic compounds and high-value reinforcing fibers therein. Summary of the Invention

[0005] The purpose of the present invention is to provide a degradable epoxy resin composite material, a preparation method thereof, and a degradation method thereof to solve the problem that organic monomers and reinforcing fibers cannot be recovered from epoxy resin composite materials in the prior art.

[0006] In order to achieve the above-mentioned invention purpose, the present invention provides the following technical solutions:

[0007] The present invention provides a degradable epoxy resin composite material, which is made of a modified epoxy resin prepolymer, a curing agent, and a fiber reinforcing material;

[0008] The preparation method of the modified epoxy resin prepolymer comprises the following steps: reacting an epoxy resin prepolymer with a modifier to obtain the modified epoxy resin prepolymer.

[0009] Preferably, the addition amount of the modifier is 5-15% of the mass of the epoxy resin prepolymer; the modifier comprises dimethylolpropionic acid or polyether polyol.

[0010] Preferably, the reaction temperature is 80-120 °C and the reaction time is 0.5-2 h.

[0011] The present invention also provides a preparation method of the degradable epoxy resin composite material described above, comprising the following steps:

[0012] (1) Mixing the modified epoxy resin prepolymer and a curing agent to obtain a degradable epoxy resin composition;

[0013] (2) Impregnating or coating a fiber reinforcing material with the degradable epoxy resin composition and then curing to obtain the degradable epoxy resin composite material.

[0014] Preferably, in the step (1), the equivalent ratio of the modified epoxy resin prepolymer to the curing agent is 1:0.8-1.1.

[0015] Preferably, the impregnation method is a pre-impregnation method or a vacuum infusion method; the coating method is a hot melt method or a solvent method.

[0016] The present invention also provides a degradation method of the degradable epoxy resin composite material described above, comprising the following steps: mixing the degradable epoxy resin composite material, a supported Ni–Co–Pd / CeO 2 catalyst and a solvent, and introducing hydrogen to carry out a degradation reaction.

[0017] Preferably, the preparation method of the supported Ni–Co–Pd / CeO 2 catalyst comprises the following steps:

[0018] S1: Mixing nickel salt, cobalt salt and palladium salt in water to obtain a precursor solution;

[0019] S2: Adding cerium oxide to the precursor solution, dropping sodium hydroxide solution to adjust the pH value to 9-10, and then successively carrying out aging, filtering, washing, drying, calcination and reduction reactions to obtain the supported Ni–Co–Pd / CeO 2 catalyst.

[0020] Preferably, the molar ratio of Ni, Co and Pd in the precursor solution is 3-5:1-2:0.5-1; the mass-volume ratio of cerium oxide to the precursor solution is 1-3 g:40-80 mL.

[0021] Preferably, the addition amount of the supported Ni–Co–Pd / CeO 2 catalyst accounts for 1-5% of the mass of the degradable epoxy resin composite; the mass-volume ratio of the degradable epoxy resin composite to the solvent is 100-200 g: 200-400 mL.

[0022] Advantages of the present invention:

[0023] (1) In the present invention, a β-hydroxy ether is introduced into the epoxy resin prepolymer by using a modifier, so that the C-O bond in the epoxy resin can be efficiently broken in the presence of a catalyst, facilitating the degradation treatment of the epoxy resin and recovering phenolic monomers.

[0024] (2) The present invention uses a supported Ni–Co–Pd / CeO 2 catalyst to degrade the epoxy resin composite. Through the synergistic effect between the three metals, the catalytic performance of the selective hydrogenolysis of the C-O bond can be significantly enhanced, and the supported Ni–Co–Pd / CeO 2 catalyst can be recycled.

[0025] (3) The degradation method provided by the present invention can effectively recover the fiber reinforcement in the epoxy resin composite, ensuring that its surface is clean and its mechanical properties are not significantly damaged. Detailed implementation manners

[0026] The present invention provides a degradable epoxy resin composite, which is made of a modified epoxy resin prepolymer, a curing agent and a fiber reinforcement;

[0027] The preparation method of the modified epoxy resin prepolymer includes the following steps: reacting the epoxy resin prepolymer with a modifier to obtain the modified epoxy resin prepolymer.

[0028] In the present invention, there is no special limitation on the type of the epoxy resin prepolymer. The present invention preferably uses a bisphenol A epoxy resin prepolymer and / or a phenol novolac epoxy resin prepolymer.

[0029] The present invention has no special limitation on the type of the fiber reinforcement, as long as it belongs to the fiber reinforcement.

[0030] In the present invention, the addition amount of the modifier is 5-15% of the mass of the epoxy resin prepolymer, preferably 8-12%, and further preferably 10%; the modifier contains dimethylolpropionic acid or polyether polyol, preferably dimethylolpropionic acid.

[0031] In the present invention, the temperature of the reaction is 80 to 120 °C, preferably 90 to 110 °C, and more preferably 100 °C, and the reaction time is 0.5 to 2 h, preferably 1 to 1.5 h.

[0032] The present invention also provides a method for preparing the degradable epoxy resin composite material described above, comprising the following steps:

[0033] (1) Mix the modified epoxy resin prepolymer and the curing agent to obtain a degradable epoxy resin composition;

[0034] (2) Impregnate or coat the fiber-reinforced material with the degradable epoxy resin composition and then cure it to obtain the degradable epoxy resin composite material.

[0035] In the present invention, in the step (1), the equivalent ratio of the modified epoxy resin prepolymer to the curing agent is 1:0.8 to 1.1.

[0036] In the present invention, an accelerator may also be added when preparing the degradable epoxy resin composition; the accelerator is preferably an imidazole-based accelerator.

[0037] In the present invention, the curing agent comprises one or more of amine curing agents, acid anhydride curing agents, imidazole curing agents, phenolic curing agents, and organic urea curing agents; the amine curing agents comprise one or more of aliphatic amines, cycloaliphatic amines, polyether amines, aromatic amines, tertiary amines and their salts, polymeric amines, and modified amines; the aliphatic amines include ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, diethylamine, aminopropyltriethoxysilane; the cycloaliphatic amines include isophorone diamine, 1,3-cyclohexanedimethanamine, cyclohexylamine, methylcyclohexylamine, dicyclohexylamine, 4,4'-diaminodicyclohexylmethane; the aromatic amines include diaminodiphenylmethane, 4,4'-diaminostilbene, 4,4'-diaminodiphenyl sulfone, m-phenylenediamine, o-phenylenediamine, p-phenylenediamine; the polymeric amines include amine compounds obtained by polymerizing any epoxy resin curing agent and an epoxide compound, and the epoxy resin curing agent is present in an excessive amount in the reaction composition; the tertiary amines and their salts include triethylamine, trimethylamine, triethanolamine, tetrabutylammonium chloride, triethyl phenylphosphonate; the acid anhydride curing agents include aliphatic acid anhydrides, aromatic acid anhydrides, cycloaliphatic acid anhydrides, and special acid anhydrides; the aliphatic acid anhydrides include succinic anhydride, glutaric anhydride, adipic anhydride, sebacic anhydride, dodecenylsuccinic anhydride; the aromatic acid anhydrides include phthalic anhydride, maleic anhydride, pyromellitic dianhydride, 3,3',4,4'-diphenyl ether dianhydride, trimellitic anhydride, ketene phthalic anhydride; the cycloaliphatic acid anhydrides include hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, dicyclopentadiene dianhydride, nadic anhydride, methylnadic anhydride; the special acid anhydrides include maleic anhydride, methyl-2-butenedioic anhydride, maleic anhydride modified products, trifluoromaleic anhydride, hydrogenated acid anhydrides (hydrogenated maleic anhydride or hydrogenated phthalic anhydride).

[0038] In the present invention, the imidazole curing agent includes monocyclic imidazole, imidazole derivatives, bis-imidazole compounds, imidazole salts, and latent imidazole curing agents; the monocyclic imidazole includes imidazole, 1-methylimidazole, 2-methylimidazole, 4-methylimidazole, 2-ethyl-4-methylimidazole, or 2-phenylimidazole; the imidazole derivatives include long-chain alkyl imidazoles, alkoxy imidazoles, ester-based imidazoles, amide-based imidazoles, or carboxyl imidazoles; the bis-imidazole compounds include 4,4'-bis(imidazolyl)benzene, 1,1'-bis(imidazolyl)ethane, 1,2-bis(imidazolyl)ethane, bis(imidazolyl)methane; the imidazole salts include imidazole tetrafluoroborate, imidazole phosphate, imidazole sulfate, or imidazole p-toluenesulfonate; the latent imidazole curing agents include N-ethylimidazole-2-formate, N-phenylimidazole derivatives, or blocked imidazole compounds; the phenolic curing agents include bisphenol A phenolic resin, phenol phenolic resin, naphthalene-based phenolic resin, biphenyl phenol-based phenolic resin, biphenyl phenol-based naphthol resin, dicyclopentadiene phenol addition resin, phenol aralkyl resin, naphthol aralkyl resin; the organic ureas include one or a mixture of two of 3-phenyl-1,1-dimethylurea, 1,3-diphenylurea, 1,3-dimethylurea, and N-(3-chlorophenyl)-N',N'-dimethylurea.

[0039] In the present invention, the impregnation method is the pre-impregnation method and the vacuum infusion method; the coating method is the hot melt method or the solvent method.

[0040] In the present invention, when the vacuum infusion method is adopted, the curing includes first curing and / or second curing; the temperature of the first curing is 80-120°C, preferably 90-110°C, more preferably 100°C, and the time is 2-4 h, preferably 1.5-3.5 h, more preferably 2 h; the temperature of the second curing is 100-180°C, preferably 120-170°C, more preferably 130-160°C, and the time is 1-3 h, preferably 1.5-2.5 h, more preferably 2 h.

[0041] The present invention also provides a degradation method for the above-mentioned degradable epoxy resin composite material, including the following steps: mixing the degradable epoxy resin composite material, the supported Ni–Co–Pd / CeO 2 catalyst and a solvent, and introducing hydrogen to carry out the degradation reaction.

[0042] In the present invention, the preparation method of the supported Ni–Co–Pd / CeO 2 catalyst includes the following steps:

[0043] S1: Mixing nickel salt, cobalt salt, and palladium salt in water to obtain a precursor solution;

[0044] S2: Add cerium oxide to the precursor solution, dropwise add sodium hydroxide solution to adjust the pH value to 9 - 10, and then successively carry out aging, filtration, washing, drying, calcination, and reduction reaction to obtain the supported Ni–Co–Pd / CeO 2 catalyst.

[0045] In the present invention, there are no special restrictions on the specific types of nickel salts, cobalt salts, and palladium salts, as long as they are nickel salts, cobalt salts, and palladium salts that can dissolve in water. In the examples of the present invention, nickel nitrate hexahydrate is preferably used as the nickel salt, cobalt nitrate hexahydrate as the cobalt salt, and palladium chloride as the palladium salt.

[0046] In the present invention, the molar ratio of Ni, Co, and Pd in the precursor solution is 3 - 5:1 - 2:0.5 - 1, preferably 4:1:1; the mass - to - volume ratio of cerium oxide to the precursor solution is 1 - 3 g:40 - 80 mL, preferably 2 g:50 - 70 mL, and more preferably 2 g:60 mL.

[0047] In the present invention, the concentration of nickel ions in the precursor mixed solution is 3 - 5 mol / L, the concentration of cobalt ions is 1 - 2 mol / L, and the concentration of palladium ions is 0.5 - 1 mol / L.

[0048] In the present invention, the aging is carried out at room temperature, and the aging time is 12 - 24 h; the drying temperature is 100 - 140 °C; the calcination temperature is 300 - 400 °C, and the calcination time is 2 - 4 h; the reduction reaction is carried out in a hydrogen atmosphere or a mixed atmosphere of hydrogen and argon, the reduction reaction temperature is 200 - 350 °C, and the reduction reaction time is 0.5 - 2 h.

[0049] In the present invention, the addition amount of the supported Ni–Co–Pd / CeO 2 catalyst accounts for 1 - 5% of the mass of the degradable epoxy resin composite material, preferably 2 - 4%, and more preferably 3%; the mass - to - volume ratio of the degradable epoxy resin composite material to the solvent is 100 - 200 g:200 - 400 mL, preferably 120 - 180 g:250 - 350 mL, and more preferably 150 g:300 mL.

[0050] In the present invention, the solvent is N - methylpyrrolidone (NMP) or γ - butyrolactone.

[0051] In the present invention, the degradable epoxy resin composite material, the supported Ni–Co–Pd / CeO 2Mix the catalyst and the solvent, and then introduce hydrogen gas to carry out the degradation reaction. After introducing hydrogen gas, the pressure is 0.5 - 2 MPa, preferably 1 MPa; the temperature of the degradation reaction is 200 - 240 °C, preferably 210 - 230 °C, more preferably 220 °C, and the time of the degradation reaction is 4 - 8 h, preferably 5 - 7 h, further preferably 6 h.

[0052] In the present invention, after the reaction is completed, cooling, filtration, rotary evaporation, and column chromatography are carried out in sequence. Among them, filtration can obtain the fiber-reinforced material and the supported Ni–Co–Pd / CeO 2 catalyst, and the monomer can be obtained by column chromatography.

[0053] The technical solutions provided by the present invention will be described in detail below with reference to the examples, but they should not be construed as limiting the protection scope of the present invention.

[0054] Preparation Example 1

[0055] Put 100 parts of E-128 bisphenol A epoxy resin prepolymer (epoxy equivalent is 190) into a reaction kettle, heat it up to 100 °C, add dimethylolpropionic acid (the addition amount is 10%), and continue to react at 100 °C for 1 h to obtain a modified epoxy resin prepolymer with a β-hydroxy ether structure.

[0056] Into the above-prepared modified epoxy resin prepolymer, add methyltetrahydrophthalic anhydride (the equivalent ratio of the modified epoxy resin prepolymer to methyltetrahydrophthalic anhydride is 1:1) and 3 parts of aminoimidazole compound (the mass ratio of 2-methylimidazole to 2-aminoimidazole is 1:1) to obtain a degradable epoxy resin composition.

[0057] Preheat the mold to 120 °C, immerse the carbon fiber in the above-prepared degradable epoxy resin composition through an impregnation tank, continuously pull the carbon fiber into the preheated mold, complete the curing in the mold cavity, and the traction speed is 0.8 m / min to obtain a degradable epoxy resin composite material.

[0058] Preparation Example 2

[0059] Put 100 parts of E-128 bisphenol A epoxy resin prepolymer (epoxy equivalent is 190) into a reaction kettle, heat it up to 100 °C, add dimethylolpropionic acid (the addition amount is 10%), and continue to react at 100 °C for 1 h to obtain a modified epoxy resin prepolymer with a β-hydroxy ether structure.

[0060] In the above-prepared modified epoxy resin prepolymer, polyetheramine D230 and isophorone diamine are added (where the mass ratio of polyetheramine D230 to isophorone diamine is 1:1.5, and the equivalent ratio of the modified epoxy resin prepolymer to the amino group is 1:1), and 0.1 part of an aminoimidazole compound (where the mass ratio of 2-methylimidazole to 2-aminoimidazole is 1:1) is added to obtain a degradable epoxy resin composition.

[0061] Place the prefabricated carbon fiber multi-layer fabric in a mold, encapsulate and evacuate; place the degradable epoxy resin composition in a vacuum tank, raise the temperature to 50 °C for defoaming, and after defoaming, inject it into the mold by vacuum infusion method. After filling, raise the temperature to 80 °C and keep it warm for 3 h for the first curing; then raise the temperature to 100 °C and keep it warm for 2 h for the second curing to obtain a degradable epoxy resin composite material.

[0062] Preparation Example 3

[0063] Put 40 parts of E-828 bisphenol A epoxy resin prepolymer (epoxy equivalent 190), 40 parts of E-901 bisphenol A epoxy resin prepolymer (epoxy equivalent 500), and 20 parts of E-638S Novolac phenol novolac epoxy resin (epoxy equivalent 180) into a reaction kettle, raise the temperature to 120 °C, add dimethylolpropionic acid (the addition amount is 15%), and continue to react at 80 °C for 1 h to obtain a modified epoxy resin prepolymer with a β-hydroxy ether structure.

[0064] In the above-prepared modified epoxy resin prepolymer, a dicyandiamide (Dicy) curing agent is added (where the equivalent ratio of the modified epoxy resin prepolymer to the amino group in dicyandiamide (Dicy) is 1:1), and 0.5 part of 1,3-dimethylurea is added to obtain a degradable epoxy resin composition.

[0065] Coat the above degradable epoxy resin composition on the carbon fiber fabric by the hot melt method, pre-react at 80 °C to make the resin reach partial curing, and cure it again during use. The curing temperature is 150 °C and the curing time is 2 h to obtain a degradable epoxy resin composite material.

[0066] Example 1

[0067] Dissolve nickel nitrate hexahydrate, cobalt nitrate hexahydrate, and palladium chloride in water to ensure that the molar ratio of Ni, Co, and Pd is 4:1:1, where the concentration of nickel ions is 4 mol / L, the concentration of cobalt ions is 1 mol / L, and the concentration of palladium ions is 1 mol / L to prepare a precursor solution.

[0068] Take 60 mL of the precursor solution, add 2 g of cerium oxide powder, stir evenly, add 1 mol / L sodium hydroxide solution to adjust the pH value to 9, then age at room temperature for 16 h, then filter and wash with deionized water until neutral, dry at 120 °C, and calcine the dried powder in an air atmosphere at 350 °C for 3 h. Then, carry out a reduction reaction on the calcined powder in a hydrogen atmosphere at 250 °C for 1 h to obtain the supported Ni–Co–Pd / CeO 2 catalyst.

[0069] Cut the epoxy resin composite material prepared in Preparation Example 1 into small pieces of about 1 cm × 1 cm, take 150 g and put it into a reaction kettle, add 300 mL of NMP and 3 g of the supported Ni–Co–Pd / CeO 2 catalyst, fill with hydrogen to make the pressure in the reaction kettle 1 MPa, then heat up to 220 °C and react under stirring conditions for 6 h. After the reaction is completed, cool to room temperature, filter to obtain carbon fiber and the supported Ni–Co–Pd / CeO 2 catalyst. Then, the filtrate is rotary evaporated to remove the solvent and bisphenol A is obtained by column chromatography with a purity of 99.4% and a yield of 85%. There is no obvious residue on the surface of the carbon fiber.

[0070] Example 2

[0071] Dissolve nickel nitrate hexahydrate, cobalt nitrate hexahydrate and palladium chloride in water to ensure that the molar ratio of Ni, Co and Pd is 3:2:0.5, where the concentration of nickel ions is 3 mol / L, the concentration of cobalt ions is 2 mol / L, and the concentration of palladium ions is 0.5 mol / L to prepare the precursor solution.

[0072] Take 60 mL of the precursor solution, add 3 g of cerium oxide powder, stir evenly, add 1 mol / L sodium hydroxide solution to adjust the pH value to 10, then age at room temperature for 24 h, then filter and wash with deionized water until neutral, dry at 140 °C, and calcine the dried powder in an air atmosphere at 400 °C for 4 h. Then, carry out a reduction reaction on the calcined powder in a hydrogen atmosphere at 200 °C for 2 h to obtain the supported Ni–Co–Pd / CeO 2 catalyst.

[0073] Cut the epoxy resin composite material prepared in Preparation Example 2 into small pieces of about 1 cm × 1 cm, take 150 g and put it into a reaction kettle, add 300 mL of NMP and 5 g of the supported Ni–Co–Pd / CeO 2The catalyst was charged with hydrogen to make the pressure in the reaction kettle 1 MPa, and then the temperature was raised to 220 °C and reacted for 6 h under stirring conditions. After the reaction ended, it was cooled to room temperature, and carbon fiber and supported Ni–Co–Pd / CeO were obtained by filtration. 2 The catalyst was then used. The filtrate was rotary evaporated to remove the solvent and bisphenol A was obtained by column chromatography with a purity of 98.6% and a yield of 89%. There was no obvious residue on the surface of the carbon fiber.

[0074] Example 3

[0075] Nickel nitrate hexahydrate, cobalt nitrate hexahydrate and palladium chloride were dissolved in water to ensure a molar ratio of Ni, Co and Pd of 5:2:1, where the concentration of nickel ions was 5 mol / L, the concentration of cobalt ions was 2 mol / L, and the concentration of palladium ions was 1 mol / L to prepare a precursor solution.

[0076] 60 mL of the precursor solution was taken, 1 g of cerium oxide powder was added, stirred evenly, and 1 mol / L sodium hydroxide solution was added dropwise to adjust the pH value to 9. Then it was aged at room temperature for 12 h, then filtered, washed with deionized water to neutrality, dried under the condition of 100 °C, and the dried powder was calcined in air atmosphere at 300 °C for 3 h. The calcined powder was reduced in hydrogen atmosphere at 300 °C for 0.5 h to prepare supported Ni–Co–Pd / CeO 2 catalyst.

[0077] The epoxy resin composite material prepared in Preparation Example 1 was cut into small pieces of about 1 cm × 1 cm, 150 g was taken and put into a reaction kettle, 300 mL of NMP and 1 g of supported Ni–Co–Pd / CeO 2 catalyst were added. Hydrogen was charged to make the pressure in the reaction kettle 1 MPa, and then the temperature was raised to 220 °C and reacted for 6 h under stirring conditions. After the reaction ended, it was cooled to room temperature, and carbon fiber and supported Ni–Co–Pd / CeO were obtained by filtration. 2 The catalyst was then used. The filtrate was rotary evaporated to remove the solvent and bisphenol A was obtained by column chromatography with a purity of 98.3% and a yield of 92%. There was no obvious residue on the surface of the carbon fiber.

[0078] The supported Ni–Co–Pd / CeO used after the degradation treatment in Examples 1 to 3 2 catalyst was washed with deionized water and dried, and finally regenerated in hydrogen atmosphere at 300 °C for 1 h to obtain the regenerated supported Ni–Co–Pd / CeO 2 catalyst. The regenerated catalyst could be reused, and the yield remained above 80% and could be reused more than 5 times, indicating that the supported Ni–Co–Pd / CeO prepared in the present invention 2The catalyst has good stability.

[0079] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and modifications can be made, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A degradable epoxy resin composite material, characterized in that: The degradable epoxy resin composite material is made of modified epoxy resin prepolymer, curing agent and fiber reinforcement material; The preparation method of the modified epoxy resin prepolymer comprises the following steps: reacting the epoxy resin prepolymer with a modifier to obtain the modified epoxy resin prepolymer.

2. The degradable epoxy resin composite material according to claim 1, characterized in that: The addition amount of the modifier is 5-15% of the mass of the epoxy resin prepolymer; the modifier comprises dimethylol propionic acid or polyether polyol.

3. The degradable epoxy resin composite material according to claim 1 or 2, characterized in that: The reaction temperature is 80-120° C., and the reaction time is 0.5-2 h.

4. The method for preparing the degradable epoxy resin composite material according to any one of claims 1 to 3, characterized in that: The steps include: (1) mixing a modified epoxy resin prepolymer and a curing agent to obtain a degradable epoxy resin composition; (2) The fiber-reinforced material is impregnated or coated with the degradable epoxy resin composition and then cured to obtain a degradable epoxy resin composite material.

5. The method for preparing the degradable epoxy resin composite material according to claim 4, characterized in that: In the step (1), the equivalent ratio of the modified epoxy resin prepolymer to the curing agent is 1:0.8-1.

1.

6. The method for preparing the degradable epoxy resin composite material according to claim 4 or 5, characterized in that: The impregnation method is a pre-impregnation method or a vacuum infusion method; the coating method is a hot melt method or a solvent method.

7. The method for degrading the degradable epoxy resin composite material according to any one of claims 1 to 3, characterized in that: The method comprises the following steps: mixing a degradable epoxy resin composite material, a supported Ni-Co-Pd / CeO2 catalyst and a solvent, and introducing hydrogen to carry out a degradation reaction.

8. The method for degrading a degradable epoxy resin composite material according to claim 7, characterized in that: The preparation method of the supported Ni-Co-Pd / CeO2 catalyst comprises the following steps: S1: mixing nickel salt, cobalt salt and palladium salt in water to obtain a precursor solution; S2: Cerium oxide is added to the precursor solution, and sodium hydroxide solution is added dropwise to adjust the pH value to 9-10, followed by aging, filtering, washing, drying, calcining and reduction reactions to obtain a supported Ni-Co-Pd / CeO2 catalyst.

9. The method for degrading a degradable epoxy resin composite material according to claim 8, characterized in that: The molar ratio of Ni, Co and Pd in ​​the precursor solution is 3-5:1-2:0.5-1; the mass volume ratio of the cerium oxide and the precursor solution is 1-3g:40-80mL.

10. The method for degrading a degradable epoxy resin composite material according to claim 8 or 9, characterized in that: The added amount of the supported Ni-Co-Pd / CeO2 catalyst accounts for 1-5% of the mass of the degradable epoxy resin composite material; the mass volume ratio of the degradable epoxy resin composite material and the solvent is 100-200g:200-400mL.