Degradable epoxy resin composite material with adjustable curing speed, preparation and mild full recycling method thereof

Abstract

A degradable epoxy resin composite material with adjustable curing speed, its preparation and mild full recycling method. The existing degradable epoxy resin has problems such as high cost, harsh degradation conditions, and is difficult to meet the requirements of curing speed and temperature for different application scenarios. The present application provides an epoxy resin composite material containing a curing agent component (epoxy resin amine curing agent and ester-containing polysulfide curing agent), an epoxy resin component (glycidyl ether, glycidyl amine, glycidyl ester epoxy resin). The cured product of the composite material can be catalytically degraded under mild conditions by using the mechanism of breaking the ester bond with Lewis acid and amino, realizing full recycling, and the degradation product can be directly used as a curing agent, a toughening agent, and a chain extender. The epoxy resin composite material of the present application not only has adjustable curing speed and high performance, but also realizes environmental friendliness and resource recycling, providing a new solution for the sustainable development of epoxy resin.

Description

Technical Field

[0001] This invention belongs to the field of biodegradable epoxy resin technology, and particularly relates to a biodegradable epoxy resin composite material with adjustable curing speed, its preparation and a mild and fully recyclable method. Background Technology

[0002] Traditional epoxy resins are widely used in many fields due to their excellent mechanical properties and chemical stability. However, these properties also make them difficult to degrade in the natural environment, resulting in long-term pollution and environmental burden. With increasing environmental awareness and the growing acceptance of sustainable development concepts, the biodegradability of epoxy resins has become particularly important. Therefore, developing biodegradable epoxy resin composites has become a crucial research topic in the field of polymer materials. Currently, although research has been conducted on developing biodegradable epoxy resin materials, existing technologies still face many challenges. For example, while dynamically bonded epoxy resins possess some biodegradability, they are expensive and have poor processability, hindering large-scale application. Furthermore, while epoxy resins containing ester groups can theoretically be degraded through alkaline hydrolysis, alcoholysis, and aminolysis, the actual degradation conditions are extremely harsh, typically requiring strong acid and alkali environments and high temperatures (usually above 120°C). For example, CN115536615B discloses a bio-based epoxy resin that, through esterification, yielded a series of compounds containing both polycarboxyl groups and double bonds. Based on these, a series of bio-based epoxy resin precursors containing ester groups and double bonds were obtained, which were then degraded using the hydrolysis of ester bonds under strongly alkaline conditions. This not only increases the cost of degradation and recycling but also inevitably leads to secondary pollution, limiting its feasibility in practical applications. Although some studies have attempted to address these issues through composite formulation design and degradation methods, numerous technical challenges remain, and widespread application breakthroughs have not yet been achieved.

[0003] Meanwhile, different application areas have their own strict requirements for the curing speed and curing temperature of epoxy resins. For example, in vacuum infusion processes, a longer gel time (100-200 minutes) is usually required to ensure uniform filling and curing effects; while for applications such as maintenance resins or adhesives, rapid curing at room temperature is necessary to improve construction efficiency and ease of use. However, current epoxy resin composites still have significant limitations in controlling the curing speed and curing temperature, making it difficult to simultaneously meet the needs of multiple application scenarios. Therefore, there is an urgent need to optimize the composition of epoxy resin composites to achieve flexible control of curing speed and curing temperature, while also considering the biodegradability and environmental friendliness of the materials. Summary of the Invention

[0004] The purpose of this invention is to address the problems of existing epoxy resins being difficult to degrade and the significant limitations in the control of curing speed and curing temperature of composite materials. This invention provides a degradable epoxy resin composite material with adjustable curing speed, as well as its preparation and a mild method for full recycling. This method can meet the requirements of low viscosity, adjustable curing speed, and high performance of epoxy resins. Furthermore, the recycling reaction conditions are mild, enabling the full recycling of both epoxy resin and reinforcement.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] A biodegradable epoxy resin composite with adjustable curing speed, the composite comprising a curing agent component, an epoxy resin component, a curing accelerator, and a toughening agent; the molar ratio of epoxy groups to active hydrogen in the curing agent is 1:1-1.2; the curing accelerator accounts for 0wt%-5wt% of the epoxy resin composite, and the toughening agent accounts for 0wt%-20wt% of the epoxy resin composite;

[0007] The curing agent comprises an epoxy resin amine curing agent and an ester-containing polythiol curing agent, wherein the ester-containing polythiol curing agent accounts for 0.1wt%-70wt% of the curing agent composition; and the epoxy resin amine curing agent accounts for 30wt%-99.9wt% of the curing agent composition.

[0008] The ester-containing polythiol curing agent is selected from one or more types and has the following general structural formula:

[0009]

[0010] R1 and R2 are one or more of the following: aliphatic carbon chains of C1-C18, benzene rings and their derivatives, and heterocyclic structures and their derivatives containing oxygen, nitrogen, sulfur, phosphorus or silicon.

[0011] The epoxy resin amine curing agent is one or more of the following: isophorone diamine, 4,4-diaminodicyclohexylmethane, 3,3'-dimethyl-4,4-diaminodicyclohexylmethane, alkyl diamine, hydrogenated diaminodiphenylmethane, N-aminoethylpiperazine, ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, diaminodiphenylmethane, diaminodiphenyl sulfone, m-phenylenediamine, polyetheramine D230, polyetheramine T403, and dicyandiamide;

[0012] The epoxy resin components include glycidyl ether epoxy resin, glycidyl amine epoxy resin, and glycidyl ester epoxy resin, wherein glycidyl ether epoxy resin and glycidyl amine epoxy resin account for 12wt%-78wt% of the epoxy resin components; and glycidyl ester epoxy resin accounts for 22wt%-88wt% of the epoxy resin components.

[0013] Further, the glycidyl ether epoxy resin is one or more of the following: bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, bisphenol S diglycidyl ether, tetrabromobisphenol A diglycidyl ether, hydrogenated bisphenol A epoxy resin, linear phenolic epoxy resin, o-cresol formaldehyde epoxy resin, neopentyl glycol diglycidyl ether, 1,4-butanediol diglycidyl ether, glycerol triglycidyl ether, trimethylolpropane triglycidyl ether, pentaerythritol tetraglycidyl ether, polypropylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, resorcinol diglycidyl ether, naphthol formaldehyde epoxy resin, biphenyl diglycidyl ether, alicyclic glycidyl ether, cyclohexanediol diglycidyl ether, and C12-C14 fatty alcohol glycidyl ether.

[0014] The glycidylamine epoxy resin is one or more of the following: 4,4'-diaminodiphenylmethane epoxy resin, triglycidyl-p-aminophenol, tetraglycidyl-m-phenylenediamine, triglycidyl carbamate, N,N,N',N'-tetraglycidyl-4,4'-diaminodiphenyl ether, and triglycidyl triisocyanate.

[0015] The glycidyl ester epoxy resin is one or more of the following: diglycidyl phthalate, hexahydrodiglycidyl phthalate, diglycidyl terephthalate, diglycidyl isophthalate, diglycidyl tetrahydrophthalate, diglycidyl methyltetrahydrophthalate, diglycidyl methylmethylenetetrahydrophthalate, diglycidyl adipate, triglycidyl trimellitate, tetraglycidyl pyromellitic acid, and soybean oil-based glycidyl ester.

[0016] Further, the curing accelerator is one or more of the following: 2,4,6-tris(dimethylaminomethyl)benzene, 1,8-diazabicyclo(5,4,0)-7-undecene, benzyl dimethylamine, 1,5,7-trizabicyclo[4.4.0]dec-5-ene, 2-ethyl-4-methylimidazolium, 1-cyanoethyl-2-ethyl-4-methylimidazolium, 2-mercaptobenzothiazole, and metal salts of acetylacetone;

[0017] The toughening agent is one or more of inorganic nanoparticles, polyether polyols, polysulfide rubber, and PU prepolymers.

[0018] Further, the ester-containing polythiol curing agent is one or more of pentaerythritol tetra(3-mercaptopropionate), dipentaerythritol hexa(3-mercaptopropionate), trimethylolpropane tri(3-mercaptopropionate), bis(3-mercaptopropionic acid) ethylene glycol di(3-mercaptopropionate), polypropylene glycol di(3-mercaptopropionate), di(2-mercaptoethyl terephthalate), triglyceride tri(3-mercaptopropionate), and di(2-mercaptoethyl adipate).

[0019] Furthermore, the composite material also includes reinforcing bodies and auxiliary materials;

[0020] The reinforcement is at least one of carbon fiber, glass fiber, natural fiber, chemical fiber and fabrics made of fiber materials, carbon nanomaterials, boron nitride nanomaterials, metal nanoparticles, metal oxide nanoparticles, and organic nanoparticles, accounting for 50wt%-65wt% of the total mass of the composite material;

[0021] The auxiliary materials are at least one of the following: accelerator, diluent, plasticizer, toughening agent, thickener, coupling agent, defoamer, leveling agent, ultraviolet absorber, antioxidant, brightener, fluorescent reagent, pigment, and filler, accounting for 0.1wt%-2wt% of the total mass of the composite material.

[0022] A method for preparing the above-mentioned biodegradable epoxy resin composite material with adjustable curing speed involves taking various raw materials according to their content and mixing them, and curing them at 25~100℃ for 1~24 h.

[0023] A mild and fully recyclable method for the above-mentioned biodegradable epoxy resin composite with adjustable curing speed is provided. The method comprises: immersing the biodegradable epoxy resin composite with adjustable curing speed in a catalytic degradation solution, and carrying out a catalytic bond-breaking reaction at 40-100℃ for 1-100 h to obtain a homogeneous degradation mixture solution; the reinforcing material can be recycled without damage after filtration, cleaning, and drying; the homogeneous degradation mixture solution can be used directly as a curing agent, toughening agent, or chain extender for epoxy resin or polyurethane without purification or separation.

[0024] Furthermore, the catalytic degradation liquid comprises a mixture of Lewis acid catalyst, amine compound, alcohol compound, and alkanolamine compound; the mass percentage of Lewis acid catalyst is 0.1%-30%, the mass percentage of amine compound is 0%-99%, the mass percentage of alcohol compound is 0%-99%, and the mass percentage of alkanolamine compound is 0%-99%.

[0025] Further, the Lewis acid catalyst is one or more selected from aluminum trichloride, ferric trichloride, titanium tetrachloride, boron trifluoride, boron trichloride, zinc chloride, trimethylaluminum, diethylzinc, triphenylboron, scandium trifluoromethanesulfonate, ytterbium trifluoromethanesulfonate, and aluminum chloride-imidazolium salt;

[0026] The amine compound is one or more selected from ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, butanediamine, hexanediamine, isophoronediamine, oleylamine, isopropylamine, tert-butylamine, benzylamine, cyclohexylamine, acrylamine, and pyrrolidineamine.

[0027] The alcohol compounds are one or more selected from methanol, ethanol, isopropanol, butanol, cyclohexanol, glycerol, ethylene glycol, propylene glycol, butanediol, pentanediol, pentaerythritol, 1,4-cyclohexanediethanol, tricyclodecanediethanol, polytetrahydrofurandiol, polypropylene glycol, castor oil-based diol, and polycarbonate diol.

[0028] The alkanolamine compound is one or more of the following: ethanolamine, diethanolamine, isopropanolamine, aminomethylpropanol, hydroxyethyl ethylenediamine, diethylene glycolamine, 1-amino-2-propanol, 1-amino-2-butanol, phenylethanolamine, 2-amino-2-methyl-1-propanol, and 2-amino-1-butanol.

[0029] The advantages of this invention over the prior art are as follows:

[0030] (1) The present invention uses an ester-containing polythiol curing agent as a degradable and adjustable curing speed functional curing agent. After reacting with epoxy resin, the introduced ester group can be dissociated under the action of amine compounds, alcohol compounds and alkanolamine compounds, thus giving it degradation and recycling properties.

[0031] (2) The ester-containing polythiol curing agent has high thiol activity and can cure epoxy resin at room temperature. By adjusting the proportion of the ester-containing polythiol curing agent, the curing speed of the epoxy resin composite can be controlled. The epoxy resin composite obtained by compounding with commercial epoxy resin and curing agent has low viscosity, adjustable reaction rate and high glass transition temperature of cured product, which can meet the process performance and performance requirements of existing wind turbine blades and maintenance resin production.

[0032] (3) The mild and fully recyclable method provided by the present invention achieves the synergistic effect of Lewis acid catalytic cleavage of CN bonds and ester dissociation reaction, and the catalytic degradation temperature is reduced to below 100°C under normal pressure. The degradation conditions are mild, the degradation process is green and there is no waste discharge. The recycled reinforcing material can be reused after separation, washing and drying. The resin degradation products can be used directly as curing agents, toughening agents and chain extenders for epoxy resin or polyurethane without any purification or separation. Detailed Implementation

[0033] The technical solution of the present invention will be further described below with reference to the embodiments, but it is not limited thereto. Any modifications or equivalent substitutions to the technical solution of the present invention without departing from the spirit and scope of the technical solution of the present invention should be covered within the protection scope of the present invention. Example 1

[0034] Degradable epoxy resin composite material with adjustable curing speed 1: The epoxy resin components are 70 parts by weight of bisphenol A diglycidyl ether epoxy resin and 30 parts by weight of diglycidyl adipate. The curing agent components are 29 parts by weight of pentaerythritol tetra(3-mercaptopropionate), 1 part by weight of 2,4,6-tris(dimethylaminomethyl)benzene, and 70 parts by weight of 4,4-diaminodicyclohexylmethane.

[0035] Preparation of degradable epoxy resin 1 cured product with adjustable curing speed: Take the above epoxy resin components and curing agent components and mix them evenly at a mass ratio of 100:37. After vacuum degassing, pour the mixture into a metal mold and cure at room temperature for 24 hours or at 60°C for 8 hours to obtain the epoxy resin casting.

[0036] Degradation and recycling: Prepare degradation solution by dissolving 1.5 g zinc chloride and 6.5 g ethanolamine in 100 mL tetrahydrofuran, take 5 g of the epoxy resin prepared above, completely immerse it in the degradation solution, seal the system and heat it to 80°C, and stir continuously for 12 h. The resin is completely degraded and dissolved in the degradation solution.

[0037] Table 1. Basic properties of biodegradable, adjustable-curing-speed epoxy resin castings

[0038]

[0039] Preparation of biodegradable epoxy resin composite material with adjustable curing speed: The composite material is prepared by vacuum infusion method. An appropriate amount of the epoxy resin composite material prepared above is prepared and kept at 30°C. After vacuum degassing, it is introduced into a vacuum bag with carbon fiber fabric to fully impregnate the resin. After ensuring that there are no air bubbles in the system, the infusion is stopped and the temperature is raised to 60°C for curing for 8 hours to obtain fiber reinforced composite material.

[0040] Degradation and recycling of the composite material: A degradation solution was prepared by dissolving 1.5 g of zinc chloride and 6.5 g of ethanolamine in 100 mL of tetrahydrofuran. Approximately 8 g of the composite material prepared above was completely immersed in the degradation solution. The system was sealed and heated to 80°C, and stirred continuously for 12 h until the resin was completely degraded and dissolved in the degradation solution. The carbon fiber fabric was then removed and ultrasonically cleaned with dichloromethane and ethanol, respectively, to obtain the recycled carbon fiber fabric without damage. Example 2

[0041] Degradable epoxy resin composite material 2 with adjustable curing speed: The epoxy resin components are 50 parts by weight of 4,4'-diaminodiphenylmethane epoxy resin and 50 parts by weight of tetrahydrophthalic acid diglycidyl ester, and the curing agent components are 15 parts by weight of pentaerythritol tetra(3-mercaptopropionate) and 85 parts by weight of m-phenylenediamine.

[0042] Preparation of biodegradable epoxy resin 2 with adjustable curing speed: Take the above epoxy resin components and curing agent components and mix them evenly at a mass ratio of 100:28. After vacuum degassing, pour the mixture into a metal mold and cure it at 80℃ for 12 hours to obtain the epoxy resin casting.

[0043] Table 2 Basic Properties of Biodegradable, Adjustable Curing Speed ​​Epoxy Resin 2

[0044]

[0045] Degradation and recycling of degradable epoxy resin 2 with adjustable curing speed: Prepare degradation solution by mixing 1 g of ferric chloride with 8 g of ethylenediamine, taking 5 g of the epoxy resin prepared above and completely immersing it in the degradation solution, sealing the system and heating it to 100°C, stirring continuously for 8 hours, and the resin is completely degraded and dissolved in the degradation solution.

[0046] Preparation of biodegradable epoxy resin composite material with adjustable curing speed: The composite material is prepared by vacuum infusion method. An appropriate amount of the epoxy resin composite material prepared above is prepared and kept at 30°C. After vacuum degassing, it is introduced into a vacuum bag with carbon fiber fabric to fully impregnate the resin. After ensuring that there are no air bubbles in the system, the infusion is stopped and the temperature is raised to 80°C for 12 hours to obtain fiber reinforced composite material.

[0047] Degradation and recycling of the composite material: A degradation solution was prepared by mixing 1 g of ferric chloride with 8 g of ethylenediamine. Approximately 8 g of the composite material prepared above was completely immersed in the degradation solution. The system was sealed and heated to 100°C, and stirred continuously for 8 hours until the resin was completely degraded and dissolved in the degradation solution. The carbon fiber fabric was then removed and ultrasonically cleaned with dichloromethane and ethanol, respectively, to obtain the recycled carbon fiber fabric without damage.

[0048] Comparative Example 1:

[0049] Comparative epoxy resin composite: The epoxy resin component is 100 parts by weight of E51 epoxy resin, and the curing agent component is 100 parts by weight of m-phenylenediamine.

[0050] Preparation of comparative epoxy resin: Take the above epoxy resin components and curing agent components and mix them evenly at a mass ratio of 100:15. After vacuum degassing, pour the mixture into a metal mold and cure it at 80°C for 12 hours to obtain the epoxy resin casting.

[0051] Table 3 Performance of Comparative Epoxy Resins

[0052]

[0053] Degradation and recycling of comparative epoxy resin: A degradation solution was prepared by mixing 1 g of ferric chloride with 8 g of ethylenediamine, and then 5 g of the epoxy resin prepared above was completely immersed in the degradation solution. The system was sealed and heated to 100°C and stirred continuously for 8 hours. The resin only showed obvious swelling and failed to degrade and dissolve in the degradation solution.

[0054] Comparing Tables 1, 2, and 3, it can be seen that the mechanical properties and thermal stability of the resin provided in the embodiments of the present invention are comparable to those of currently commercially available epoxy resins, meeting most application requirements. However, in terms of degradability, the resin provided in the embodiments of the present invention can rapidly degrade under mild conditions below 100 °C, completely dissolving in solution, which facilitates the non-destructive recovery of carbon fibers in composite materials and the recycling and reuse of the recovered products. However, the resin in the comparative examples, due to its stable three-dimensional structure, failed to degrade under comparable conditions. This demonstrates that the epoxy resin system prepared by the method provided in this invention has excellent thermodynamic properties and degradability.

Claims

1. A method for the complete recycling of biodegradable epoxy resin composites with adjustable curing speed, characterized in that: The composite material includes a curing agent component, an epoxy resin component, a curing accelerator, and a toughening agent; the molar ratio of epoxy groups to active hydrogen in the curing agent is 1:1~1.2; the curing accelerator accounts for 0wt%~5wt% of the epoxy resin composite material, and the toughening agent accounts for 0wt%~20wt% of the epoxy resin composite material. The curing agent consists of an epoxy resin amine curing agent and an ester-containing polythiol curing agent, wherein the ester-containing polythiol curing agent accounts for 0.1 wt% to 70 wt% of the curing agent composition; and the epoxy resin amine curing agent accounts for 30 wt% to 99.9 wt% of the curing agent composition. The epoxy resin amine curing agent is one or more of the following: isophorone diamine, 4,4-diaminodicyclohexylmethane, 3,3'-dimethyl-4,4-diaminodicyclohexylmethane, alkyl diamine, hydrogenated diaminodiphenylmethane, N-aminoethylpiperazine, ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, diaminodiphenylmethane, diaminodiphenyl sulfone, m-phenylenediamine, polyetheramine D230, polyetheramine T403, and dicyandiamide; The epoxy resin component includes glycidyl ether epoxy resin, glycidyl amine epoxy resin, and glycidyl ester epoxy resin, wherein glycidyl ether epoxy resin and glycidyl amine epoxy resin account for 12wt%~78wt% of the epoxy resin component; and glycidyl ester epoxy resin accounts for 22wt%~88wt% of the epoxy resin component. The curing accelerator is one or more of the following: 2,4,6-tris(dimethylaminomethyl)benzene, 1,8-diazabicyclo(5,4,0)-7-undecene, benzyl dimethylamine, 1,5,7-trizabicyclo[4.4.0]dec-5-ene, 2-ethyl-4-methylimidazolium, 1-cyanoethyl-2-ethyl-4-methylimidazolium, 2-mercaptobenzothiazole, and metal salts of acetylacetone; The toughening agent is one or more of inorganic nanoparticles, polyether polyols, polysulfide rubber, and PU prepolymers; The ester-containing polythiol curing agent is one or more of the following: pentaerythritol tetra(3-mercaptopropionate), dipentaerythritol hexa(3-mercaptopropionate), trimethylolpropane tri(3-mercaptopropionate), bis(3-mercaptopropionic acid) ethylene glycol, polyethylene glycol di(3-mercaptopropionate), polypropylene glycol di(3-mercaptopropionate), di(2-mercaptoethyl terephthalate), triglyceride tri(3-mercaptopropionate), and di(2-mercaptoethyl adipate); The mild and fully recyclable method for the biodegradable epoxy resin composite with adjustable curing speed is as follows: the biodegradable epoxy resin composite with adjustable curing speed is immersed in a catalytic degradation solution and subjected to a catalytic bond-breaking reaction at 40~100℃ for 1~100 h to obtain a homogeneous degradation mixture solution; the reinforcement can be recycled without damage after filtration, cleaning and drying; the homogeneous degradation mixture solution can be used directly as a curing agent, toughening agent and chain extender for epoxy resin or polyurethane without purification and separation; The catalytic degradation solution is a mixture of Lewis acid catalyst, amine compounds, alcohol compounds, and alkanolamine compounds; the mass percentage of Lewis acid catalyst is 0.1%~30%, the mass percentage of amine compounds is 0%~99%, the mass percentage of alcohol compounds is 0%~99%, and the mass percentage of alkanolamine compounds is 0%~99%. The Lewis acid catalyst is one or more of the following: aluminum trichloride, ferric trichloride, titanium tetrachloride, boron trifluoride, boron trichloride, zinc chloride, trimethylaluminum, diethylzinc, triphenylboron, scandium trifluoromethanesulfonate, ytterbium trifluoromethanesulfonate, and aluminum chloride-imidazolium salt. The amine compound is one or more selected from ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, butanediamine, hexanediamine, isophoronediamine, oleylamine, isopropylamine, tert-butylamine, benzylamine, cyclohexylamine, acrylamine, and pyrrolidineamine. The alcohol compounds are one or more selected from methanol, ethanol, isopropanol, butanol, cyclohexanol, glycerol, ethylene glycol, propylene glycol, butanediol, pentanediol, pentaerythritol, 1,4-cyclohexanediethanol, tricyclodecanediethanol, polytetrahydrofurandiol, polypropylene glycol, castor oil-based diol, and polycarbonate diol. The alkanolamine compound is one or more selected from ethanolamine, diethanolamine, isopropanolamine, aminomethylpropanol, hydroxyethyl ethylenediamine, diethylene glycolamine, 1-amino-2-propanol, 1-amino-2-butanol, phenylethanolamine, 2-amino-2-methyl-1-propanol, and 2-amino-1-butanol. The glycidyl ether epoxy resin is one or more of the following: bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, bisphenol S diglycidyl ether, tetrabromobisphenol A diglycidyl ether, hydrogenated bisphenol A epoxy resin, linear phenolic epoxy resin, o-cresol formaldehyde epoxy resin, neopentyl glycol diglycidyl ether, 1,4-butanediol diglycidyl ether, glycerol triglycidyl ether, trimethylolpropane triglycidyl ether, pentaerythritol tetraglycidyl ether, polypropylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, resorcinol diglycidyl ether, naphthol formaldehyde epoxy resin, biphenyl diglycidyl ether, alicyclic glycidyl ether, cyclohexanediol diglycidyl ether, and C12-C14 fatty alcohol glycidyl ether. The glycidylamine epoxy resin is one or more of the following: 4,4'-diaminodiphenylmethane epoxy resin, triglycidyl-p-aminophenol, tetraglycidyl-m-phenylenediamine, triglycidyl carbamate, N,N,N',N'-tetraglycidyl-4,4'-diaminodiphenyl ether, and triglycidyl triisocyanate. The glycidyl ester epoxy resin is one or more of the following: diglycidyl phthalate, hexahydrodiglycidyl phthalate, diglycidyl terephthalate, diglycidyl isophthalate, diglycidyl tetrahydrophthalate, diglycidyl methyltetrahydrophthalate, diglycidyl methylmethylenetetrahydrophthalate, diglycidyl adipate, triglycidyl trimellitate, tetraglycidyl pyromellitic acid, and soybean oil-based glycidyl ester. The composite material also includes reinforcing materials and auxiliary materials; The reinforcement is at least one of carbon fiber, glass fiber, natural fiber, chemical fiber and fabrics made of fiber materials, carbon nanomaterials, boron nitride nanomaterials, metal nanoparticles, metal oxide nanoparticles, and organic nanoparticles, accounting for 50wt% to 65wt% of the total mass of the composite material; The auxiliary materials are at least one of diluent, plasticizer, thickener, coupling agent, defoamer, leveling agent, ultraviolet absorber, antioxidant, brightener, fluorescent agent, and pigment, accounting for 0.1wt% to 2wt% of the total mass of the composite material.

2. The method for the complete recycling of biodegradable epoxy resin composites with adjustable curing speed according to claim 1, characterized in that: The composite material is prepared by taking various raw materials according to their content and mixing them, and then curing them at 25~100℃ for 1~24h.

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