Fatigue-resistant degradable epoxy resin composite material and preparation and degradation method thereof

Abstract

The invention discloses a fatigue-resistant degradable epoxy resin composite material and a preparation and degradation method thereof, and belongs to the technical field of fatigue-resistant recyclable epoxy resin. The composite material comprises a component A and a component B, the mass ratio of the component A to the component B is 100: (30-65), and every 100 parts of the component A comprises 0-94% of epoxy resin, 0-50% of an epoxy resin diluent, 1-30% of an epoxy resin anti-fatigue catalyst and 5-60% of an epoxy resin modifier; every 100 parts of the component B comprises 10%-90% of an amine curing agent, 5%-85% of an anhydride curing agent and 0%-5% of an accelerant. The epoxy resin modifier is added, dynamic covalent bonds are introduced into an epoxy resin cross-linked network, when the dynamic covalent bonds are subjected to external stimulation, the dynamic covalent bonds in the cross-linked network are broken, a three-dimensional network is temporarily or permanently depolymerized, waste epoxy resin can be degraded under a certain condition, and the environmental pollution pressure is relieved.

Description

Technical Field

[0001] The invention belongs to the technical field of fatigue-resistant and recyclable epoxy resins, and particularly relates to a fatigue-resistant and degradable epoxy resin composite material and a preparation and degradation method thereof. Background Art

[0002] Epoxy resin is an important type of thermosetting plastic. After curing, it has the characteristics of high strength, light weight, and weather resistance. It is widely used in aerospace, wind power, electronic packaging and other fields. However, when epoxy resin is exposed to high temperature, high humidity, ultraviolet light and other application scenarios for a long time, molecular chain breakage, cross-linking network destruction or stress concentration will cause structural damage such as microcracks, which greatly affects the service life of the epoxy resin material. In addition, similar to other traditional thermosetting plastics, epoxy resin is insoluble and infusible after curing. The irreversible covalent network hinders its degradation, reshaping and reprocessing, resulting in serious environmental and resource waste. Therefore, how to ensure that epoxy resin products maintain excellent comprehensive performance over a long service life and carry out scientific degradation treatment and recycling after retirement has become a difficult problem in the epoxy resin field.

[0003] Designing a fatigue-resistant, degradable epoxy resin composite can effectively solve the above problems. At present, the methods for enhancing the fatigue resistance of epoxy resin mainly include introducing toughening agents, nanoparticles, fibers or dynamic covalent bonds into the resin formula. The introduced toughening agents include rubber elastomers and thermoplastics. Rubber elastomers can absorb energy by inducing silver streaks and shear yielding, thereby inhibiting crack propagation; the introduction of thermoplastics can produce an interpenetrating network with epoxy, enhancing toughness and thus improving fatigue resistance; the introduction of nanoparticles can improve the fatigue life of epoxy resin by hindering crack propagation and limiting the slippage of molecular chains. For example, patent CN119570233A discloses a polymer-modified epoxy resin toughening agent, which contains a nano-silicon dioxide / nano-zirconium dioxide mixture to obtain a high-strength, high-toughness, and high-heat-resistant epoxy resin system. However, the fillers introduced by the above methods have a series of problems such as increased viscosity of the epoxy resin composition after addition, making it difficult to meet the infusion requirements of large structural parts and being difficult to degrade and recycle. In addition, the current degradation and recycling of epoxy resins mostly relies on high temperature and high pressure environments and complex post-degradation processing processes. Summary of the Invention

[0004] To overcome the shortcomings of the aforementioned prior art, the present invention provides a fatigue-resistant, degradable epoxy resin composite, as well as its preparation and degradation methods. This fatigue-resistant, degradable epoxy resin composite offers low viscosity, good fluidity, and a long pot life, meeting the requirements for the infusion of large structural components. The cured product exhibits excellent mechanical properties and fatigue resistance. The epoxy resin composite undergoes mild degradation conditions and a simple recycling process, reducing the cost of post-processing waste epoxy resin cured products.

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

[0006] A fatigue-resistant and degradable epoxy resin composite material comprises a component A and a component B; the component A comprises an epoxy resin, an epoxy resin diluent, an epoxy resin fatigue-resistant catalyst, and an epoxy resin modifier; the component B comprises an amine curing agent, an acid anhydride curing agent, and an accelerator; the mass ratio of the component A to the component B is 100:30-65, wherein every 100 parts of the component A comprises 0%-94% of the epoxy resin, 0%-50% of the epoxy resin diluent, 1%-30% of the epoxy resin fatigue-resistant catalyst, and 5%-60% of the epoxy resin modifier; and every 100 parts of the component B comprises 10%-90% of the amine curing agent, 5%-85% of the acid anhydride curing agent, and 0%-5% of the accelerator.

[0007] Furthermore, the epoxy resin includes one or more of glycidyl ether epoxy resin and glycidyl amine epoxy resin; the glycidyl ether epoxy resin is 、 、 、 、 One or more of the following: the epoxy value of the epoxy resin ranges from 0.44 to 0.7 mol / 100 g, and the viscosity at 25°C is 500 to 3000 mPa·s.

[0008] The epoxy value is 0.440 mol / 100g ~0.588 mol / 100g. The appearance is a transparent viscous liquid with a viscosity of 1000~2400mPa·s at 25℃.

[0009] The epoxy value is 0.575mol / 100g-0.595mol / 100g, the appearance is colorless viscous liquid, and the density is 1.16g / cm 3 .

[0010] The epoxy value is 0.640mol / 100g-0.694mol / 100g, the appearance is light yellow viscous liquid, and the density is 1.16g / cm 3 .

[0011] Furthermore, the epoxy resin diluent is at least one of 1,4-butanediol diglycidyl ether, ethylene glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, benzyl glycidyl ether, butyl glycidyl ether, and phenyl glycidyl ether. The epoxy resin diluent is a low-molecular-weight compound having one or more epoxy groups. The epoxy groups can directly participate in the curing reaction of the epoxy resin, becoming part of the epoxy resin cross-linking network. Furthermore, the epoxy resin diluent's relatively low molecular weight can reduce the viscosity of the epoxy resin composite, thereby meeting the requirements for epoxy resin vacuum infusion.

[0012] Furthermore, the epoxy resin fatigue-resistant catalyst is one or more of an organic base catalyst, a metal salt catalyst, an ionic liquid catalyst, a supramolecular catalyst, and a nanocatalyst; the organic base catalyst is at least one of 1,5,7-triazabicyclo[4.4.0]dec-5-ene or 4-dimethylaminopyridine; the metal salt catalyst is at least one of zinc acetylacetonate, zinc acetate, zinc octoate, dibutyltin dilaurate, or tetraisopropyl titanate; the ionic liquid catalyst is at least one of 1-butyl-3-methylimidazole acetate or choline acetate; the supramolecular catalyst is a ureidopyrimidone derivative; and the nanocatalyst is zinc oxide nanoparticles. The epoxy resin fatigue-resistant catalyst can catalyze the breakage and recombination of dynamic bonds under stimuli such as heat or light, promoting the autonomous repair of damaged areas.

[0013] Furthermore, the epoxy resin modifier is a glycidyl ester having a specific structure. The structural formula of the epoxy resin modifier is as follows:

[0014]

[0015] Wherein, R is one or more of a C1-C18 aliphatic carbon chain, a benzene ring and its derivatives, and a heterocyclic structure containing oxygen, nitrogen, silicon, phosphorus, sulfur, or selenium, and its derivatives; R1 is selected from at least one of a methylene group and a cyclohexyl group; and R2 and R3 are each independently a hydrogen atom, a C1-C18 aliphatic carbon chain, a benzene ring and its derivatives, and a structure containing a carboxyl group, a hydroxyl group, an aldehyde group, or an epoxy group. One or more compounds having this structure are selected; in this embodiment, trimethylolpropane triglycidyl ester, diglycidyl hexahydrophthalate, and diglycidyl terephthalate are selected.

[0016] Furthermore, the amine curing agent is one or more of aromatic amine, aliphatic amine or polyether amine; the aromatic amine is one or more of m-phenylenediamine (MPD), diaminodiphenylmethane (DDM), diaminodiphenyl sulfone (DDS), and methylaniline; the aliphatic amine is one or more of menthanediamine (MDA), 1,3-bis(aminomethyl)cyclohexane, diaminodicyclohexylmethane (PACM), 3,3'-dimethyl-4,4-diaminodicyclohexylmethane (MACM), 4,4'-diaminodicyclohexylmethane, and isophoronediamine (IPDA); the selection criteria of the polyether amine are polymers with a molecular weight of 230 to 2000, at least two terminal amino groups, a main chain of a polyether structure, and an amino group as the terminal active functional group. The polyetheramine includes one or more of D230, D400, and D2000, wherein D represents difunctionality, and 230, 400, and 2000 represent molecular weights of 230, 400, and 2000, respectively.

[0017] Furthermore, the acid anhydride curing agent is one or more of phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, and methylhexahydrophthalic anhydride; and the accelerator is one or more of 2,4,6-tris(dimethylaminomethyl)phenol, benzyldimethylamine, triethanolamine, 2-ethyl-4-methylimidazole, and 1-cyanoethyl-2-ethyl-4-methylimidazole.

[0018] A method for preparing the above-mentioned fatigue-resistant and degradable epoxy resin composite material comprises: weighing component A and component B according to a set mass ratio; mixing the component A and the component B respectively and evenly, and then mixing to obtain a mixture; ultrasonically defoaming the mixture and then curing it at 80-200°C for 1-10 hours to obtain a fatigue-resistant and degradable epoxy resin body.

[0019] A degradation method for a fatigue-resistant degradable epoxy resin body prepared by the above-mentioned preparation method comprises: immersing 1 part of the fatigue-resistant degradable epoxy resin body in 1-10 parts of a degradation liquid according to a mass ratio, heating the body to 80-150° C. to carry out a degradation reaction for 0.5-10 hours, and then adding deionized water in an amount of 1-5 times the weight of the degradation liquid mixture to the obtained degradation mixture to precipitate and separate the degradation products, thereby obtaining a precipitated first degradation product and a liquid second degradation product.

[0020] Furthermore, the degradation liquid is a mixture of an ionic liquid, a strong base and a degradation solvent; the ionic liquid accounts for 0.5wt% to 30wt% of the degradation liquid, the strong base accounts for 0.5wt% to 30wt% of the degradation liquid, and the degradation solvent accounts for 50wt% to 99wt% of the degradation liquid;

[0021] The ionic liquid is an ionic liquid containing imidazolium, ammonium, pyridinium and phosphonium cations, and is paired with various halide anions, including at least one of 1-butyl-3-methylimidazolium chloride ([Bmim] [Cl]), tetrabutylphosphine bromide ([TBP] [Br]), 1-butyl-2-methylpyridinium chloride ([BmPyr] [Cl]), 1-ethyl-3-methylimidazolium chloride ([Emim] [Cl]), 1-butyl-1-methylpiperidinium iodide ([BmPip] [I]), and 1-butyl-1-methylpyrrolidinium chloride ([BmPyrr] [Cl]);

[0022] The strong base is at least one of 1,5,7-triazabicyclo[4.4.0]decene-5-ene TBD, 1,8-diazabicyclo[5.4.0]undec-7-ene DBU, 1,5-diazabicyclo[4.3.0]non-5-ene DBN, and tetramethylguanidine TMG;

[0023] The degradation solvent is at least one of pure water, ethanol, ethylene glycol, propylene glycol, ethanolamine, diethylenetriamine, and triethylenetetramine.

[0024] A method for fully recycling the above-mentioned degradation products includes the following utilization routes: the above-mentioned first degradation product is mixed with epoxy resin to prepare secondary utilization epoxy resin, and the second degradation product is distilled and reused as degradation liquid.

[0025] Compared with the prior art, the advantages of the present invention are: by adding an epoxy resin modifier, dynamic covalent bonds are introduced into the epoxy resin cross-linked network; when the dynamic covalent bonds are subjected to external stimulation, the dynamic covalent bonds in the cross-linked network are broken, resulting in temporary or permanent depolymerization of the three-dimensional network, so that the waste epoxy resin can be degraded under certain conditions, alleviating the pressure of environmental pollution; by screening the epoxy resin fatigue-resistant catalyst, a certain proportion of fatigue-resistant catalyst components are added to the epoxy resin composite, and through carbonyl activation or deprotonation, the carbonyl carbon in the epoxy resin system is susceptible to nucleophilic attack, thereby selectively catalyzing dynamic ester exchange, so that the dynamic ester bonds are preferentially broken and reorganized during stress cycles, reconstructing the cross-linked network and dissipating energy, thereby extending the service life of the epoxy resin; using the ionic liquid + strong base + degradation solvent mode, through the solvation and catalysis of the ionic liquid, the nucleophilic attack of the strong base and the synergistic effect of the solvent, the epoxy resin is rapidly and mildly degraded, and the degradation products can be fully recovered and reused after simple post-processing, further reducing the post-processing cost. DETAILED DESCRIPTION

[0026] The technical solution of the present invention is further described below with reference to the embodiments, but is not limited thereto. Any modification or equivalent replacement of the technical solution of the present invention that does not depart from the spirit and scope of the technical solution of the present invention should be included in the scope of protection of the present invention.

[0027] Example 1

[0028] Prepare a fatigue-resistant biodegradable epoxy resin composite material, wherein the weight ratio of component A to component B is 100:30, wherein every 100 parts of component A includes: 24.8 copies, 25.2 parts, 1,4-butanediol diglycidyl ether 1.7 parts, zinc acetylacetonate 4.7 parts, trimethylolpropane triglycidyl ester 43.6 parts; every 100 parts of component B includes: aromatic amine (DDM) 15.8 parts, fatty amine (PACM) 32.3 parts, polyetheramine D230 37.2 parts, phthalic anhydride 14.2 parts, triethanolamine 0.5 parts.

[0029] Example 2

[0030] Prepare a fatigue-resistant biodegradable epoxy resin composite material, wherein the weight ratio of component A to component B is 100:37, wherein every 100 parts of component A includes: 26.5 servings, 8.5 parts, ethylene glycol diglycidyl ether 9.4 parts, 1,5,7-triazabicyclo[4.4.0]dec-5-ene 13.8 parts, terephthalic acid diglycidyl ester 41.8 parts; every 100 parts of component B include: aromatic amine (DDM) weighed 34.1 parts, fatty amine (PACM weighed 12.3 parts, MACM weighed 24.7 parts), polyetheramine D230 weighed 14.3 parts, hexahydrophthalic anhydride weighed 12.6 parts, 2,4,6-tris(dimethylaminomethyl)phenol weighed 2 parts.

[0031] Example 3

[0032] Prepare a fatigue-resistant biodegradable epoxy resin composite material, wherein the weight ratio of component A to component B is 100:42, wherein every 100 parts of component A includes: 43.7 copies, 18.9 parts, 7.7 parts of 1,6-hexanediol diglycidyl ether, 9.1 parts of zinc acetate, 20.6 parts of hexahydrophthalic acid diglycidyl ester; every 100 parts of component B include: aromatic amine (MPD) weighed 10.9 parts, fatty amine (IPDA weighed 32.8 parts, MACM weighed 32.1 parts), polyetheramine D400 weighed 4.2 parts, methyltetrahydrophthalic anhydride weighed 18.7 parts, benzyldimethylamine weighed 1.3 parts.

[0033] Example 4

[0034] Prepare a fatigue-resistant biodegradable epoxy resin composite material, wherein the weight ratio of component A to component B is 100:47, wherein every 100 parts of component A includes: Weigh 19.8 parts, Weigh 35.1 parts, Weigh 22.5 parts, 1,4-butanediol diglycidyl ether weigh 5.8 parts, zinc acetylacetonate weigh 3.1 parts, trimethylolpropane triglycidyl ester weigh 13.7 parts; every 100 parts of component B include: aromatic amine (DDS) weigh 34.3 parts, fatty amine (IPDA weigh 12.9 parts, PACM weigh 12.1 parts), polyetheramine D400 weigh 21.2 parts, hexahydrophthalic anhydride weigh 15.7 parts, 1-cyanoethyl-2-ethyl-4-methylimidazole weigh 3.8 parts.

[0035] Example 5

[0036] Prepare a fatigue-resistant biodegradable epoxy resin composite material, wherein the weight ratio of component A to component B is 100:50, wherein every 100 parts of component A includes: Weigh 34.9 parts, Weigh 22.5 parts, 1,6-hexanediol diglycidyl ether weigh 2.2 parts, zinc acetate weigh 3.6 parts, terephthalic acid diglycidyl ester weigh 36.8 parts; every 100 parts of component B includes: aromatic amine (DDM) weighed 52.1 parts, fatty amine (MACM) weighed 12.2 parts, polyetheramine D230 weighed 12.2 parts, phthalic anhydride weighed 20.8 parts, and 2-ethyl-4-methylimidazole weighed 2.7 parts.

[0037] Example 6

[0038] Prepare a fatigue-resistant biodegradable epoxy resin composite material, wherein the weight ratio of component A to component B is 100:50, wherein every 100 parts of component A includes: Weigh 13.6 parts, Weigh 35.4 parts, Weigh 15.4 parts of 1,6-hexanediol diglycidyl ether, 5.8 parts of 1,6-hexanediol diglycidyl ether, 12.5 parts of zinc acetate, and 17.3 parts of terephthalic acid diglycidyl ester; every 100 parts of component B include: aromatic amine (MPD) weighed 13.7 parts, fatty amine (PACM) weighed 22.8 parts, polyetheramine D230 weighed 34.5 parts, methyltetrahydrophthalic anhydride weighed 26.4 parts, and benzyldimethylamine weighed 2.6 parts.

[0039] Example 7

[0040] Prepare a fatigue-resistant biodegradable epoxy resin composite material, wherein the weight ratio of component A to component B is 100:33, wherein every 100 parts of component A includes: Weigh 34.5 parts, Weigh 35.5 parts of propylene glycol, 1.3 parts of ethylene glycol diglycidyl ether, 2.2 parts of dibutyltin dilaurate, and 26.5 parts of hexahydrophthalic acid diglycidyl ester; every 100 parts of component B include: 5.5 parts of aromatic amine (DDM), 5.6 parts of fatty amine (MACM), 3.4 parts of polyetheramine D400, 84.3 parts of tetrahydrophthalic anhydride, and 1.2 parts of 1-cyanoethyl-2-ethyl-4-methylimidazole.

[0041] Example 8

[0042] Prepare a fatigue-resistant biodegradable epoxy resin composite material, wherein the weight ratio of component A to component B is 100:54, wherein every 100 parts of component A includes: Weigh 13.5 parts, Weigh 16.9 parts, 1,4-butanediol diglycidyl ether weigh 4.6 parts, zinc acetylacetonate weigh 10.7 parts, trimethylolpropane triglycidyl ester weigh 54.3 parts; every 100 parts of component B include: aromatic amine (DDM) weigh 5.3 parts, fatty amine (MACM weigh 31.4 parts, IPDA weigh 14.2 parts), polyetheramine D230 weigh 36.1 parts, hexahydrophthalic anhydride weigh 10.9 parts, and triethanolamine weigh 2.1 parts.

[0043] Example 9

[0044] Prepare a fatigue-resistant biodegradable epoxy resin composite material, wherein the weight ratio of component A to component B is 100:61, wherein every 100 parts of component A includes: Weigh 23.6 parts, Weigh 21.1 parts, ethylene glycol diglycidyl ether weigh 9.2 parts, zinc acetate weigh 14.9 parts, hexahydrophthalic acid diglycidyl ester weigh 31.2 parts; every 100 parts of component B include: aromatic amine (DDM) weigh 34.2 parts, fatty amine (PACM weigh 11.3 parts, IPDA weigh 2.8 parts), polyetheramine D400 weigh 32.1 parts, methyltetrahydrophthalic anhydride weigh 18.6 parts, and 2-ethyl-4-methylimidazole weigh 1 part.

[0045] Example 10

[0046] Prepare a fatigue-resistant biodegradable epoxy resin composite material, wherein the weight ratio of component A to component B is 100:65, wherein every 100 parts of component A includes: Weigh 22.8 parts, Weigh 31.5 parts, 1,6-hexanediol diglycidyl ether weigh 8.7 parts, 1,5,7-triazabicyclo[4.4.0]dec-5-ene weigh 9.9 parts, terephthalic acid diglycidyl ester weigh 27.1 parts; every 100 parts of component B include: aromatic amine (DDM) weigh 11.7 parts, fatty amine (PACM weigh 15.6 parts, IPDA weigh 13.8 parts, MACM weigh 27.9 parts), polyetheramine D230 weigh 20.6 parts, phthalic anhydride weigh 7.5 parts, 2,4,6-tris(dimethylaminomethyl)phenol weigh 2.9 parts.

[0047] Example 11

[0048] Prepare a fatigue-resistant biodegradable epoxy resin composite material, wherein the weight ratio of component A to component B is 100:44, wherein every 100 parts of component A includes: Weigh 41.2 parts, 1,4-butanediol diglycidyl ether weigh 7.7 parts, zinc acetate weigh 6.4 parts, trimethylolpropane triglycidyl ester weigh 44.7 parts; every 100 parts of component B include: aromatic amine (MPD) weigh 2.4 parts, fatty amine (PACM weigh 22.1 parts, IPDA weigh 5.8 parts, MACM weigh 33.6 parts), polyetheramine D2000 weigh 1.4 parts, hexahydrophthalic anhydride weigh 32.6 parts, benzyldimethylamine weigh 2.1 parts.

[0049] Example 12

[0050] Prepare a fatigue-resistant biodegradable epoxy resin composite material, wherein the weight ratio of component A to component B is 100:47, wherein every 100 parts of component A includes: Weigh 44.1 parts, 9.4 parts of 1,6-hexanediol diglycidyl ether, 6.1 parts of zinc acetylacetonate, and 40.4 parts of hexahydrophthalic acid diglycidyl ester; every 100 parts of component B include: fatty amine (22.4 parts of PACM, 13.2 parts of IPDA, and 31.5 parts of MACM), 21.9 parts of polyetheramine D230, 9.6 parts of tetrahydrophthalic anhydride, and 1.4 parts of 2,4,6-tris(dimethylaminomethyl)phenol.

[0051] Example 13

[0052] Prepare a fatigue-resistant biodegradable epoxy resin composite material, wherein the weight ratio of component A to component B is 100:52, wherein every 100 parts of component A includes: Weigh 43.1 parts, 1,4-butanediol diglycidyl ether weigh 10 parts, dibutyltin dilaurate weigh 7.5 parts, terephthalic acid diglycidyl ester weigh 39.4 parts; every 100 parts of component B include: aromatic amine (DDM) weigh 22.1 parts, fatty amine (IPDA weigh 12.7 parts, MACM weigh 25.3 parts), polyetheramine D230 weigh 26.1 parts, methyltetrahydrophthalic anhydride weigh 10.2 parts, 2-ethyl-4-methylimidazole weigh 3.6 parts.

[0053] The composite materials of the above embodiments are all prepared by the following method: component A and component B are weighed according to a set mass ratio; the components A and B are mixed evenly, and then mixed to obtain a mixture; the mixture is ultrasonically defoamed and then cured at 80~200℃ for 1~10h to obtain a fatigue-resistant and degradable epoxy resin body.

[0054] The fatigue-resistant degradable epoxy resin body obtained in the above embodiment was tested according to the national standard, and the performance data obtained are shown in the following table:

[0055] Table 1 Performance table of the embodiment

[0056]

[0057] Example 14

[0058] The fatigue-resistant, degradable epoxy resin was degraded using the epoxy resin obtained by curing in Example 5. The weight ratio of epoxy resin to degradation solution was 1:1. For every 100 parts of degradation solution, the solution comprised 5 parts 1-butyl-3-methylimidazolium chloride, 5 parts TBD, and 90 parts ethanolamine. Under nitrogen protection, the solution was stirred at 80°C for 10 hours to complete degradation, yielding a pale yellow solution.

[0059] Example 15

[0060] The fatigue-resistant, degradable epoxy resin was degraded using the epoxy resin obtained by curing in Example 8. The weight ratio of epoxy resin to degradation solution was 1:3. For every 100 parts of degradation solution, the solution consisted of 10 parts 1-butyl-2-methylpyridinium chloride, 14 parts TBD, and 76 parts pure water. Under nitrogen protection, the solution was stirred at 98°C for 6 hours to complete degradation, yielding a pale yellow solution.

[0061] Example 16

[0062] The fatigue-resistant, degradable epoxy resin was degraded using the epoxy resin obtained by curing in Example 9. The weight ratio of epoxy resin to degradation solution was 1:5. Per 100 parts of the degradation solution, the solution comprised 10 parts 1-ethyl-3-methylimidazolium chloride, 10 parts TBD, and 80 parts diethylenetriamine. Under nitrogen protection, the solution was stirred at 150°C for 3 hours to complete degradation, yielding a pale yellow solution.

[0063] Example 17

[0064] The fatigue-resistant, degradable epoxy resin was degraded using the epoxy resin obtained by curing in Example 11. The weight ratio of epoxy resin to degradation solution was 1:4. Per 100 parts of the degradation solution, the solution comprised 15 parts 1-butyl-1-methylpyrrolidinoammonium chloride, 20 parts TBD, and 65 parts propylene glycol. Under nitrogen protection, the solution was stirred at 120°C for 4 hours to complete degradation, yielding a pale yellow solution.

[0065] Example 18

[0066] Recycling of fatigue-resistant, biodegradable epoxy resin degradation products. The degradation mixture from Example 15 was selected, and deionized water (twice the volume of the mixture) was added. The mixture was stirred and allowed to stand until the solids were completely precipitated. A solid first degradation product and a liquid second degradation product were separated. The solid first degradation product was mixed with E51 and cured using MACM. The cured resin had a tensile strength of 58 MPa and an elongation at break of 3.2%. The liquid second degradation product, after rotary evaporation to remove the deionized water, was used as the degradation liquid to degrade the epoxy resin cured in Example 8. Under nitrogen protection, the resin was completely degraded by stirring at 110°C for 4 hours.

[0067] Comparative Example 1

[0068] Preparation of epoxy resin composite without adding fatigue-resistant catalyst: The weight ratio of component A to component B is 100:65, wherein every 100 parts of component A includes: Weigh 27.8 parts, Weigh 35.5 parts, 1,6-hexanediol diglycidyl ether weigh 8.7 parts, and diglycidyl terephthalate weigh 28 parts; every 100 parts of component B include: aromatic amine (DDM) weigh 11.7 parts, fatty amine (PACM weigh 15.6 parts, IPDA weigh 13.8 parts, MACM weigh 27.9 parts), polyetheramine D230 weigh 20.6 parts, phthalic anhydride weigh 7.5 parts, and 2,4,6-tris(dimethylaminomethyl)phenol weigh 2.9 parts.

[0069] The comprehensive properties of the epoxy resin obtained by curing the comparative example and the epoxy resin obtained by curing the embodiment 10 are compared as follows:

[0070]

[0071] Comparative Example 1: Degradation of epoxy resin. The epoxy resin obtained by curing in Comparative Example 1 was subjected to degradation. The weight ratio of epoxy resin to degradation solution was 1:5. Per 100 parts of the degradation solution, the following components were present: 10 parts 1-ethyl-3-methylimidazolium chloride, 10 parts TBD, and 80 parts diethylenetriamine. Under nitrogen atmosphere, the mixture was stirred at 150°C for 3 hours for complete degradation, yielding a pale yellow solution. This indicates that the fatigue-resistant catalyst has no negative impact on the degradation performance of the epoxy resin.

[0072] Comparative Example 1: Recycling of epoxy resin degradation products. A degradation mixture from Comparative Example 1 was prepared. Deionized water (twice the volume of the mixture) was added to the mixture. The mixture was stirred and allowed to stand until the solids were completely precipitated. A solid first degradation product and a liquid second degradation product were separated. The first degradation product was mixed with E51 and cured using MACM. The cured resin had a tensile strength of 61 MPa and an elongation at break of 2.9%. The liquid second degradation product, after rotary evaporation to remove the deionized water, was used as the degradation solution to degrade the epoxy resin obtained in Comparative Example 1. Under nitrogen protection, the resin was completely degraded by stirring at 110°C for 4 hours.

Claims

1. A fatigue-resistant and degradable epoxy resin composite, characterized by: The composite material includes component A and component B; the mass ratio of component A to component B is 100:30-65, wherein every 100 parts of component A includes 0%-94% epoxy resin, 0%-50% epoxy resin diluent, 1%-30% epoxy resin anti-fatigue catalyst, and 5%-60% epoxy resin modifier; and every 100 parts of component B includes 10%-90% amine curing agent, 5%-85% acid anhydride curing agent, and 0%-5% accelerator.

2. The fatigue-resistant and degradable epoxy resin composite according to claim 1, characterized in that: The epoxy resin includes one or more of glycidyl ether epoxy resin and glycidyl amine epoxy resin; the glycidyl ether epoxy resin is 、 、 、 、 One or more of the following: the epoxy value of the epoxy resin ranges from 0.44 to 0.7 mol / 100 g, and the viscosity at 25°C is 500 to 3000 mPa·s.

3. The fatigue-resistant and degradable epoxy resin composite according to claim 1, characterized in that: The epoxy resin diluent is at least one of 1,4-butanediol diglycidyl ether, ethylene glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, benzyl glycidyl ether, butyl glycidyl ether, and phenyl glycidyl ether.

4. The fatigue-resistant and degradable epoxy resin composite according to claim 1, wherein: The epoxy resin fatigue-resistant catalyst is one or more of an organic base catalyst, a metal salt catalyst, an ionic liquid catalyst, a supramolecular catalyst, and a nanocatalyst; the organic base catalyst is at least one of 1,5,7-triazabicyclo[4.4.0]dec-5-ene and 4-dimethylaminopyridine; the metal salt catalyst is at least one of zinc acetylacetonate, zinc acetate, zinc octoate, dibutyltin dilaurate, and tetraisopropyl titanate; the ionic liquid catalyst is at least one of 1-butyl-3-methylimidazole acetate and choline acetate; the supramolecular catalyst is a ureidopyrimidone derivative; and the nanocatalyst is zinc oxide nanoparticles.

5. The fatigue-resistant and degradable epoxy resin composite according to claim 1, characterized in that: The structural formula of the epoxy resin modifier is as follows: Wherein, R is one or more structures selected from a C1-C18 aliphatic carbon chain, a benzene ring and its derivatives, and a heterocyclic structure containing oxygen, nitrogen, silicon, phosphorus, sulfur or selenium and its derivatives; R1 is selected from at least one structure selected from a methylene group and a cyclohexyl group; R2 and R3 are each independently a hydrogen atom, a C1-C18 aliphatic carbon chain, a benzene ring and its derivatives, and a structure containing a carboxyl group, a hydroxyl group, an aldehyde group or an epoxy group; 6. The fatigue-resistant and degradable epoxy resin composite according to claim 1, characterized in that: The amine curing agent is one or more of aromatic amine, aliphatic amine or polyetheramine; the aromatic amine is one or more of m-phenylenediamine, diaminodiphenylmethane, diaminodiphenylsulfone and methylaniline; the aliphatic amine is one or more of menthanediamine, 1,3-bis(aminomethyl)cyclohexane, diaminodicyclohexylmethane, 3,3'-dimethyl-4,4-diaminodicyclohexylmethane, 4,4'-diaminodicyclohexylmethane and isophoronediamine; the polyetheramine is selected from the group consisting of a polymer having a molecular weight of 230 to 2000, at least two terminal amino groups, a main chain of a polyether structure, and an amino group as a terminal active functional group.

7. The fatigue-resistant and degradable epoxy resin composite according to claim 1, characterized in that: The acid anhydride curing agent is one or more of phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, and methylhexahydrophthalic anhydride; the accelerator is one or more of 2,4,6-tris(dimethylaminomethyl)phenol, benzyldimethylamine, triethanolamine, 2-ethyl-4-methylimidazole, and 1-cyanoethyl-2-ethyl-4-methylimidazole.

8. A method for preparing the fatigue-resistant and degradable epoxy resin composite according to any one of claims 1 to 7, characterized in that: The method comprises the following steps: weighing component A and component B according to a set mass ratio; uniformly mixing the component A and the component B respectively, and then mixing to obtain a mixture; ultrasonically defoaming the mixture and then curing the mixture at 80-200° C. for 1-10 hours to obtain a fatigue-resistant and degradable epoxy resin body.

9. A method for degrading the fatigue-resistant degradable epoxy resin body prepared by the preparation method according to claim 8, characterized in that: The method comprises the following steps: immersing 1 part of a fatigue-resistant degradable epoxy resin body in 1 to 10 parts of a degradation liquid according to a mass ratio, heating the mixture to 80 to 150° C. to carry out a degradation reaction for 0.5 to 10 hours, and then adding deionized water in an amount of 1 to 5 times the weight of the degradation liquid mixture to the obtained degradation mixture to precipitate and separate the degradation products, thereby obtaining a precipitated first degradation product and a liquid second degradation product.

10. The method for degrading a fatigue-resistant and degradable epoxy resin body according to claim 9, characterized in that: The degradation solution is a mixture of an ionic liquid, a strong base and a degradation solvent; the ionic liquid accounts for 0.5wt% to 30wt% of the degradation solution, the strong base accounts for 0.5wt% to 30wt% of the degradation solution, and the degradation solvent accounts for 50wt% to 99wt% of the degradation solution; The ionic liquids are ionic liquids containing imidazolium, ammonium, pyridinium and phosphonium cations, and are paired with various halide anions; The strong base is at least one of 1,5,7-triazabicyclo[4.4.0]decene-5-ene, 1,8-diazabicyclo[5.4.0]undec-7-ene, 1,5-diazabicyclo[4.3.0]non-5-ene, and tetramethylguanidine; The degradation solvent is at least one of pure water, ethanol, ethylene glycol, propylene glycol, ethanolamine, diethylenetriamine, and triethylenetetramine.

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