High-toughness high-modulus epoxy resin-based prepreg, and preparation method and application thereof

Abstract

The application discloses a high-toughness and high-modulus epoxy resin-based prepreg as well as a preparation method and application thereof. A phenolic monomer of phenoxy resin is used as a reaction medium to synthesize a modifier, and the phenoxy resin generated by the participation of the phenolic monomer is further modified, so that continuous synthesis of the modified phenoxy resin is realized, intermediate product treatment is avoided, the process is simplified, and the use of a high-pollution solvent is avoided. In addition, a high-rigidity group is introduced into the phenoxy resin, so that toughening is realized, the deformation of a cross-linking network of a cured product is reduced, the modulus of a matrix resin is improved, and interface enhancement between the high-rigidity resin matrix and high-strength and high-modulus carbon fibers is realized, so that the compatibility is improved.

Description

Technical Field

[0001] This invention belongs to the field of composite material preparation, and in particular relates to a high-toughness, high-modulus epoxy resin-based prepreg, its preparation method, and its application. Background Technology

[0002] To meet the high strength and high modulus requirements for further weight reduction in fields such as aerospace structural materials and high-end sports equipment, research on third-generation high-strength and high-modulus carbon fibers M40X and M46X, as well as corresponding prepregs, has attracted much attention.

[0003] Phenoxy resin, also known as polyphenolic resin, polyphenolic resin, or polyhydroxy ether, has been studied as a commonly used toughening agent for epoxy resins. For example, Chinese patent CN106589826A discloses a phenoxy resin-epoxy resin premix and its preparation method, as well as a resin composition for carbon fiber prepreg and its preparation method. The phenoxy resin premix is ​​prepared by increasing the molecular weight through the reaction of phenoxy resin and epoxy resin. The resulting epoxy resin for carbon fiber prepreg exhibits excellent toughness, with an impact strength reaching 25.25 kJ / m. 2 However, due to the low modulus of phenoxy resin and the low modulus of the matrix resin, the glass transition temperature (Tg) decreases. For example, in the study "Performance Research of Novel Biphenyl-Containing Phenoxy Resins and Their Blend Composites," a tetramethylbiphenyl structure was introduced into phenoxy resin, thereby increasing the molecular chain rotation resistance and significantly improving the modulus and Tg of the phenoxy resin (by nearly 59°C compared to ordinary bisphenol A type phenoxy resin). However, its toughness still does not meet the requirements.

[0004] Therefore, there is an urgent need to develop an epoxy resin-based prepreg with high toughness and high modulus. Summary of the Invention

[0005] To address at least some of the technical problems in the prior art, the present invention provides a high-toughness, high-modulus epoxy resin-based prepreg, its preparation method, and its applications. Specifically, the present invention includes the following:

[0006] A first aspect of the present invention provides a method for preparing a high-toughness, high-modulus epoxy resin-based prepreg, comprising the following steps:

[0007] (1) A bisphenol compound, a diamine and a dianhydride are reacted at 170-240°C for 0.5-24 h, and a first epoxy resin and a catalyst are added at 130-200°C. The reaction is continued for 0.1-12 h to obtain a modified phenoxy resin, wherein the viscosity of the modified phenoxy resin is 1-1,000,000 centipoise.

[0008] (2) The modified phenoxy resin and the second epoxy resin are mixed, heated and melted, and mixed with a latent curing agent to obtain an epoxy resin matrix for prepreg, wherein the first epoxy resin and the second epoxy resin may be the same or different.

[0009] (3) The epoxy resin matrix is ​​coated and combined with reinforcing fibers or fabric prepreg to obtain the high toughness and high modulus epoxy resin prepreg.

[0010] In some embodiments, according to the method for preparing high-toughness, high-modulus epoxy resin-based prepreg of the present invention, in step (1), the amount of catalyst is 0.01-2% of the total mass of the first epoxy resin and the bisphenol compound; the molecular weight of the modified phenoxy resin is 5000-50,000.

[0011] In some embodiments, according to the method for preparing high-toughness, high-modulus epoxy resin-based prepreg of the present invention, the bisphenol compound includes at least one of bisphenol A, bisphenol F, bisphenol S, diallyl bisphenol A, and diallyl bisphenol S; the diamine includes at least one of diaminodiphenylmethane, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, 2,2'-bis[4-(4-aminophenoxyphenyl)]propane, 1,3-bis(4'-aminophenoxy)benzene, and 1,4-bis(4'-aminophenoxy)benzene; the dianhydride includes at least one of bisphenol A type diether dianhydride, 3,3',4,4'-benzophenone tetracarboxylic dianhydride, 3,3',4,4'-diphenyl ether tetracarboxylic dianhydride, 2,3,3',4'-biphenyltetracarboxylic dianhydride, and 2,2'-bis(3,4-dicarboxyphenyl)hexafluoropropane tetracarboxylic dianhydride.

[0012] In some embodiments, according to the method for preparing high-toughness, high-modulus epoxy resin-based prepreg of the present invention, the first epoxy resin includes at least one of bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, and bisphenol AD ​​type epoxy resin.

[0013] In some embodiments, according to the method for preparing high-toughness, high-modulus epoxy resin-based prepreg of the present invention, the catalyst comprises at least one of quaternary ammonium salt, triphenylphosphine and its derivatives.

[0014] In some embodiments, according to the method for preparing high-toughness, high-modulus epoxy resin-based prepreg of the present invention, the second epoxy resin includes at least one of bisphenol A glycidyl ether, bisphenol F glycidyl ether, o-cresol epoxy resin, glycidylamine epoxy resin, glycidyl ester epoxy resin, alicyclic epoxy resin, and phenolic epoxy resin.

[0015] In some embodiments, according to the method for preparing high-toughness, high-modulus epoxy resin-based prepregs of the present invention, the latent curing agent includes at least one of dicyandiamide, modified dicyandiamide, urea derivatives, and diaminodiphenyl sulfone.

[0016] In some embodiments, according to the method for preparing high-toughness, high-modulus epoxy resin-based prepreg of the present invention, the reinforcing fiber or fabric comprises high-strength, high-modulus carbon fiber or fabric.

[0017] In some embodiments, according to the method for preparing high-toughness, high-modulus epoxy resin-based prepreg of the present invention, the reinforcing fiber or fabric comprises MX grade carbon fiber or fabric.

[0018] In a second aspect, the present invention provides a high-toughness, high-modulus epoxy resin-based prepreg obtained by the preparation method described in the first aspect of the present invention.

[0019] A third aspect of the invention provides the application of the high-toughness, high-modulus epoxy resin-based prepreg according to the second aspect of the invention in aerospace structural materials and high-end sports equipment.

[0020] The present invention has the following beneficial effects:

[0021] (1) Using the common phenolic monomers of phenoxy resin as solvents, the reaction products of diamine and dianhydride are used to modify the phenoxy resin generated by the phenolic monomers, so as to achieve continuous synthesis and avoid intermediate product processing. Therefore, the process is reasonable and simple, and avoids the use of highly polluting solvents such as DMAc.

[0022] (2) High-rigidity molecular polyimide was introduced to reduce the deformation of the cross-linking network of the cured product while toughening the phenyloxy resin, thereby increasing the modulus of the matrix resin; interface reinforcement was achieved between the high-rigidity resin matrix and the high-strength and high-modulus carbon fiber, improving compatibility; effectively improving the modulus of the composite material and achieving the matching between epoxy resin and high-strength and high-modulus carbon fiber. Detailed Implementation

[0023] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0024] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that the upper and lower limits of the range and each intermediate value between them are specifically disclosed. Any stated value or intermediate value within a stated range, as well as each smaller range between any other stated value or intermediate value within said range, are also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0025] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0026] Preparation method

[0027] One aspect of the present invention provides a method for preparing a high-toughness, high-modulus epoxy resin-based prepreg. In a preferred embodiment, the preparation method of the present invention includes the following steps:

[0028] (1) The bisphenol compound, diamine, and dianhydride are reacted at 170-240°C, preferably 175-235°C, even more preferably 180-230°C, for example 180, 185, 190, 195, 200, 205, 210, 215, 220, 225, 230°C for 0.5-24 h, preferably 1-23 h, even more preferably 2-22 h, further preferably 3-21 h, more preferably 4-20 h, for example 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20 h, at... The first epoxy resin and catalyst are added at 130-200℃, preferably 140-200℃, and even more preferably 150-200℃, for example 150, 155, 160, 165, 170, 175, 180, 185, 190, 195, 200℃, and the reaction is continued for 0.1-12h, preferably 1-12h, even more preferably 2-12h, further preferably 3-11h, and more preferably 4-10h, for example 4, 5, 6, 7, 8, 9, 10h, to obtain the modified phenoxy resin, wherein the viscosity of the modified phenoxy resin is controlled to be 1-1,000,000 centipoise;

[0029] (2) The modified phenoxy resin and the second epoxy resin are mixed, heated and melted, and mixed with a latent curing agent to obtain an epoxy resin matrix for prepreg, wherein the first epoxy resin and the second epoxy resin may be the same or different.

[0030] (3) The epoxy resin matrix is ​​coated and combined with reinforcing fibers or fabric prepreg to obtain the high toughness and high modulus epoxy resin prepreg.

[0031] In step (1) of this invention, the diamine and dianhydride are preferably reacted in an inert gas, examples of which include, but are not limited to, nitrogen and argon. The first epoxy resin and the catalyst can be added simultaneously, or the first epoxy resin can be added first, and the reaction can proceed for a period of time (preferably 1-20 min, more preferably 5-15 min, for example 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 min) before adding the catalyst.

[0032] To improve the toughness and modulus of the epoxy resin-based prepreg, the epoxy equivalent of the first epoxy resin can be controlled to be 100-260 g / mol, preferably 120-240 g / mol, even more preferably 140-220 g / mol, further preferably 160-200 g / mol, and more preferably 180-190 g / mol, such as 180, 181, 182, 183, 184, 185, 186, 187, 188, 189, 190 g / mol, or any value within the above range. In a preferred embodiment, the epoxy equivalent of the first epoxy resin is 186.5 g / mol.

[0033] To improve the toughness and modulus of the epoxy resin-based prepreg, the epoxy equivalent of the second epoxy resin can be controlled to be 50-200 g / mol, preferably 70-180 g / mol, even more preferably 90-160 g / mol, further preferably 100-140 g / mol, more preferably 100-120 g / mol, and even more preferably 105-115 g / mol, for example 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115 g / mol, or any value within the above range. In a preferred embodiment, the epoxy equivalent of the second epoxy resin is 110.2 g / mol.

[0034] To improve the toughness and modulus of epoxy resin-based prepregs, the viscosity of the modified phenoxy resin can be controlled to be 1-1,000,000 centipoise, preferably 50,000-950,000 centipoise, even more preferably 100,000-900,000 centipoise, further preferably 150,000-850,000 centipoise, and more preferably 150,000-800,000 centipoise, for example, 150,000, 200,000, 250, 300, 350, 400, 450, 500, 550, 600, 650, 700, 750, 800,000 centipoise. In one preferred embodiment, the viscosity of the modified phenoxy resin is 700,000 centipoise. In another preferred embodiment, the viscosity of the modified phenoxy resin is 350,000 centipoise. In yet another preferred embodiment, the viscosity of the modified phenoxy resin is 150,000 centipoise.

[0035] To improve the toughness and modulus of epoxy resin-based prepregs, the amounts of bisphenol compounds and catalysts can be controlled within appropriate ranges. In this invention, the amount of the bisphenol compound is 40-99% of the total mass of the initial materials (i.e., the bisphenol compound, diamine, and dianhydride), preferably 40-95%, more preferably 40-90%, for example 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%). The amount of the catalyst is 0.01-2% of the total mass of the first epoxy resin and the bisphenol compound, preferably 0.05-1.5%, even more preferably 0.1-1%, for example 0.1%, 0.12%, 0.14%, 0.16%, 0.18%, 0.2%, 0.21%, 0.22%, 0.24%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%.

[0036] In one preferred embodiment, the amount of the bisphenol compound is 50% of the total mass of the initial materials, and the amount of the catalyst is 0.14% of the total mass of the first epoxy resin and the bisphenol compound. In another preferred embodiment, the amount of the bisphenol compound is 40% of the total mass of the initial materials, and the amount of the catalyst is 0.12% of the total mass of the first epoxy resin and the bisphenol compound. In yet another preferred embodiment, the amount of the bisphenol compound is 90% of the total mass of the initial materials, and the amount of the catalyst is 0.21% of the total mass of the first epoxy resin and the bisphenol compound.

[0037] To improve the toughness and modulus of epoxy resin-based prepregs, the molecular weight of the polyimide can be controlled to be between 1,500 and 30,000, for example, 1,500, 5,000, 10,000, 15,000, 20,000, 25,000, or 30,000. The molecular weight of the modified phenoxy resin is between 5,000 and 50,000, preferably 7,000 to 50,000, and even more preferably 9,000 to 50,000, for example, 9,000, 10,000, 15,000, 20,000, 25,000, 30,000, 35,000, 40,000, 45,000, or 50,000, or any value within the above range. In one preferred embodiment, the molecular weight of the polyimide is 30,000, and the molecular weight of the modified phenoxy resin is 50,000. In another preferred embodiment, the molecular weight of the polyimide is 1,500, and the molecular weight of the modified phenoxy resin is 10,000. In yet another preferred embodiment, the molecular weight of the polyimide is 25,000, and the molecular weight of the modified phenoxy resin is 40,000.

[0038] In this invention, the bisphenol compounds include at least one of bisphenol A, bisphenol F, bisphenol S, diallyl bisphenol A, and diallyl bisphenol S; the diamines include at least one of diaminodiphenylmethane, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, 2,2'-bis[4-(4-aminophenoxyphenyl)]propane, 1,3-bis(4'-aminophenoxy)benzene, and 1,4-bis(4'-aminophenoxy)benzene; the dianhydrides include at least one of bisphenol A type diether dianhydride, 3,3',4,4'-benzophenone tetracarboxylic dianhydride, 3,3',4,4'-diphenyl ether tetracarboxylic dianhydride, 2,3,3',4'-biphenyltetracarboxylic dianhydride, and 2,2'-bis(3,4-dicarboxyphenyl)hexafluoropropane tetracarboxylic dianhydride.

[0039] In one preferred embodiment, the bisphenol compound is diallyl bisphenol A, the diamine is 1,3-bis(4'-aminophenoxy)benzene, and the dianhydride is 2,3,3',4'-biphenyltetracarboxylic dianhydride. In another preferred embodiment, the bisphenol compound is bisphenol A, the diamine is 2,2'-bis[4-(4-aminophenoxyphenyl)]propane, and the dianhydride is a bisphenol A-type diether dianhydride. In yet another preferred embodiment, the bisphenol compound is diallyl bisphenol A, the diamine is 4,4'-diaminodiphenyl ether, and the dianhydride is 3,3',4,4'-diphenyl ethertetracarboxylic dianhydride.

[0040] In this invention, the first epoxy resin includes a bisphenol-type epoxy resin. The bisphenol-type epoxy resin is not particularly limited, and examples include, but are not limited to, at least one of bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, and bisphenol AD ​​type epoxy resin. In a preferred embodiment, the first epoxy resin is a bisphenol A epoxy resin.

[0041] In this invention, the catalyst is not particularly limited, and examples include, but are not limited to, quaternary ammonium salts, triphenylphosphine, and their derivatives. In one preferred embodiment, the catalyst is ethyltriphenylphosphine bromide. In another preferred embodiment, the catalyst is triphenylphosphine. In yet another preferred embodiment, the catalyst is tetrabutylammonium bromide.

[0042] In this invention, the second epoxy resin is not particularly limited, and examples include, but are not limited to, bisphenol A glycidyl ether, bisphenol F glycidyl ether, o-cresol epoxy resin, glycidylamine epoxy resin, glycidyl ester epoxy resin, alicyclic epoxy resin, phenolic epoxy resin, etc. In a preferred embodiment, the second epoxy resin is a tetraglycidylamine type epoxy resin.

[0043] In this invention, the latent curing agent is not particularly limited, and examples include, but are not limited to, at least one of dicyandiamide, modified dicyandiamide, urea derivatives, and diaminodiphenyl sulfone. In a preferred embodiment, the latent curing agent is diaminodiphenyl sulfone.

[0044] In this invention, the reinforcing fiber or fabric is not particularly limited, and examples include, but are not limited to, high-strength, high-modulus carbon fibers or fabrics, such as MX grade, MJ grade, TG grade carbon fibers or fabrics, etc.

[0045] This invention uses common phenolic monomers (such as bisphenol compounds) of phenoxy resin as solvents and diamines and dianhydrides as reactants to synthesize polyimides. Then, bisphenol-type epoxy resin is added to the bisphenol compounds to synthesize phenoxy resin, yielding polyimide-modified phenoxy resin. This achieves continuous synthesis of modified phenoxy resin, avoiding intermediate product processing and the use of highly polluting solvents such as DMAc required in traditional polyimide synthesis. The molecular weight of the polyimide is preferably 15 million to 30,000, and the molecular weight of the modified phenoxy resin is preferably 50 million to 50,000.

[0046] High-toughness, high-modulus epoxy resin-based prepreg

[0047] In one aspect, the present invention provides a high-toughness, high-modulus epoxy resin-based prepreg obtained by the preparation method described in the present invention.

[0048] In a preferred embodiment, the high-toughness, high-modulus epoxy resin-based prepreg is prepared from raw materials comprising: 1-600 parts by weight of a bisphenol compound, 1-50 parts by weight of a diamine, 1-50 parts by weight of a dianhydride, 0.01-5 parts by weight of a catalyst, 5-200 parts by weight of a first epoxy resin, 10-4000 parts by weight of a second epoxy resin, and 5-1200 parts by weight of a latent curing agent.

[0049] In this invention, the tensile modulus and toughness of the epoxy resin-based prepreg can be determined using methods and apparatus known in the art, and are not particularly limited thereto. In a preferred embodiment, the high-toughness, high-modulus epoxy resin-based prepreg of this invention has a tensile modulus of not less than 200 GPa and a tensile modulus of not less than 709 J / m. 2 Fracture toughness.

[0050] application

[0051] One aspect of the present invention provides the application of the high-toughness, high-modulus epoxy resin-based prepreg described according to the present invention in aerospace structural materials and high-end sports equipment. Examples of the aerospace structural materials include, but are not limited to, primary load-bearing components (e.g., but not limited to wing spars, wing boxes, wing ribs, etc.), secondary load-bearing structures (e.g., but not limited to fairings, hatches, control surfaces, etc.), engine components (e.g., but not limited to fan blades, nacelle liners, etc.), and spacecraft structures (e.g., but not limited to probe structures, fuel tanks, etc.). Examples of the high-end sports equipment include, but are not limited to, racing cars, mountain bikes, tennis rackets, golf clubs, skis, ski poles, ice hockey sticks, racing boats, surfboards, etc.

[0052] Example 1

[0053] The following illustrates the preparation method of high-toughness, high-modulus epoxy resin-based prepreg and its composite materials.

[0054] (1) In a reactor, accurately add 509.1 g of the diamine 1,3-bis(4'-aminophenoxy)benzene (TPE-R), 502.7 g of 2,3,3',4-biphenyltetracarboxylic dianhydride (α-BPDA), and 1011.8 g of bisphenol A. Under nitrogen protection, heat the materials to 230°C and react for 4 hours. At this point, the viscosity is 700,000 centipoise (at 120°C for 30 minutes). Cool the system to 200°C and accurately add bisphenol A. 1700.7 g of phenol A epoxy resin (Nan Ya Plastics Industrial Co., Ltd. NPEL128, epoxy equivalent 186.5 g / mol) was reacted for 10 minutes, and then 3.7 g of ethyltriphenylphosphine bromide catalyst was added. The reaction was continued for 4 hours, at which point the viscosity was 700,000 centipoise (at 150°C for 30 minutes). The modified phenoxy resin was obtained by discharging the material. The amount of bisphenol solvent was 50% of the total mass of the initial material, and the molecular weight of the modified phenoxy resin was 50,000.

[0055] (2) Take 5 phr (parts by weight, the same below) of the modified phenoxy resin and add it to 100 phr of tetraglycidylamine type epoxy resin (Nantong Xinnaxi New Material Co., Ltd. Syna-Epoxy 720, epoxy equivalent 110.2 g / mol) and melt it evenly. Use 30 phr of diaminodiphenyl sulfone (DDS) as curing agent to prepare epoxy resin matrix for prepreg.

[0056] (3) The above-mentioned resin matrix is ​​coated and combined with M40X carbon fiber to obtain a high-toughness, high-modulus epoxy resin-based prepreg.

[0057] (4) The obtained prepreg is cut, laid up and shaped to obtain epoxy / carbon fiber composite material.

[0058] Example 2

[0059] The following illustrates the preparation method of high-toughness, high-modulus epoxy resin-based prepreg and its composite materials.

[0060] (1) In a reaction vessel, accurately add 278.3 g of the diamine 2,2'-bis[4-(4-aminophenoxyphenyl)]propane (BAPP), 501.3 g of bisphenol A type diether dianhydride (BPADA), and 1169.4 g of diallyl bisphenol A. Under nitrogen protection, heat the materials to 180°C and react for 20 hours. At this point, the viscosity is 250,000 centipoise (at 120°C for 30 minutes). Then, lower the system temperature to 180°C and accurately... 2370.6 g of bisphenol A epoxy resin (NPEL128 from Nan Ya Plastics Industrial Co., Ltd., epoxy equivalent 186.5 g / mol) was added and reacted for 10 minutes. Then, 4.3 g of triphenylphosphine catalyst was added and reacted for 10 hours. At this time, the viscosity was 350,000 centipoise (at 150°C for 30 minutes). The modified phenoxy resin was obtained by discharging the material. The amount of bisphenol solvent was 40% of the total mass of the initial material, and the molecular weight of the modified phenoxy resin was 10,000.

[0061] (2) The modified phenoxy resin 5 phr (parts by weight, the same below) was added to 100 phr of tetraglycidylamine type epoxy resin (Nantong Xinnaxi New Material Co., Ltd. Syna-Epoxy 720, epoxy equivalent 110.2 g / mol) and melted evenly. The epoxy resin matrix for prepreg was prepared using 30 phr of diaminodiphenyl sulfone as curing agent.

[0062] (3) The above-mentioned resin matrix is ​​coated and combined with M40X carbon fiber to obtain a high-toughness, high-modulus epoxy resin-based prepreg.

[0063] (4) The obtained prepreg is cut, laid up and shaped to obtain epoxy / carbon fiber composite material.

[0064] Example 3

[0065] The following illustrates the preparation method of high-toughness, high-modulus epoxy resin-based prepreg and its composite materials.

[0066] (1) In a reactor, accurately add 328.1 g of the diamine 4,4'-diaminodiphenyl ether (ODA), 500.1 g of 3,3',4,4'-diphenyl ether tetracarboxylic dianhydride (ODPA), 16.7 g of the catalyst benzoimidazole, and 7604.1 g of diallyl bisphenol A. Under nitrogen protection, heat the materials to 190°C and react for 8 hours. At this point, the viscosity is 80,000 centipoise (at 120°C for 30 minutes). Then, lower the system temperature to 150°C. Add 3834.5 g of bisphenol A epoxy resin (Nan Ya Plastics Industrial Co., Ltd. NPEL128, epoxy equivalent 186.5 g / mol), react for 10 minutes, then add 24.5 g of tetrabutylammonium bromide catalyst, and react for 5 hours. At this time, the viscosity is 150,000 centipoise (150℃ constant temperature for 30 minutes). The modified phenoxy resin is obtained by discharging the material. The amount of bisphenol solvent is 90% of the total mass of the initial material, and the molecular weight of the modified phenoxy resin is 40,000.

[0067] (2) Take 5 phr (parts by weight, the same below) of the modified phenoxy resin and add it to 100 phr of tetraglycidylamine type epoxy resin (Nantong Xinnaxi New Material Co., Ltd. Syna-Epoxy 720, epoxy equivalent 110.2 g / mol) and melt it evenly. Use 30 phr of diaminodiphenyl sulfone as curing agent to prepare epoxy resin matrix for prepreg.

[0068] (3) The above-mentioned resin matrix is ​​coated and combined with M40X carbon fiber to obtain a high-toughness, high-modulus epoxy resin-based prepreg.

[0069] (4) The obtained prepreg is cut, laid up and shaped to obtain epoxy / carbon fiber composite material.

[0070] Comparative Example 1

[0071] The following illustrates the preparation methods of epoxy resin-based prepregs and their composites.

[0072] (1) Add 5 phr of phenoxy resin (U.S. Union Carbide PKHH) to 100 phr of tetraglycidylamine type epoxy resin (Nantong Xinnaxi New Material Co., Ltd. Syna-Epoxy 720, epoxy equivalent 110.2 g / mol) in the reactor and melt evenly. Use 30 phr of diaminodiphenyl sulfone as curing agent to prepare epoxy resin matrix for prepreg.

[0073] (2) The above-mentioned resin matrix is ​​coated and combined with M40X carbon fiber to obtain epoxy resin prepreg;

[0074] (3) The obtained prepreg is cut, laid up and shaped to obtain epoxy / carbon fiber composite material.

[0075] Comparative Example 2

[0076] The following illustrates the preparation methods of epoxy resin-based prepregs and their composites.

[0077] (1) Add 5 phr of polyimide and phenoxy resin mixture (Changzhou Shangke New Material Co., Ltd. polyimide SK0180 and American Linke phenoxy resin PKHH, SK0180 accounts for 25.1%) to 100 phr of tetraglycidylamine type epoxy resin (Nantong Xinnaxi New Material Co., Ltd. Syna-Epoxy 720, epoxy equivalent 110.2 g / mol) in the reactor and melt it evenly. Use 30 phr of diaminodiphenyl sulfone as curing agent to prepare epoxy resin matrix for prepreg.

[0078] (2) The above-mentioned resin matrix is ​​coated and combined with M40X carbon fiber to obtain epoxy resin prepreg;

[0079] (3) The obtained prepreg is cut, laid up and shaped to obtain epoxy / carbon fiber composite material.

[0080] The properties of the composite materials in Examples 1-3 and Comparative Examples 1-2 were tested. The tensile modulus of the composite materials was obtained by testing with an Instron-1121 universal testing machine, according to the test standard GB 3354. The interlaminar fracture toughness of the composite materials was obtained by testing with an Instron-1121 universal testing machine, according to the test standard HB 7402. The test results are shown in Table 1.

[0081] Table 1 Properties of different composite materials

[0082]

[0083] The results show that the epoxy resin-based prepreg obtained by the method of the present invention not only improves the toughness of the composite material, but also increases its modulus.

[0084] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing a high-toughness, high-modulus epoxy resin-based prepreg, characterized in that, Includes the following steps: (1) Make 1 600 parts by weight of a bisphenol compound, 1-50 parts by weight of a diamine and 1-50 parts by weight of a dianhydride are reacted at 170-240°C for 0.5-24 h. Then, 5-200 parts by weight of a first epoxy resin and 0.01-5 parts by weight of a catalyst are added at 130-200°C, and the reaction is continued for 0.1-12 h to obtain a modified phenoxy resin, wherein the viscosity of the modified phenoxy resin is 1-1,000,000 centipoise. (2) The modified phenoxy resin and 10-4000 parts by weight of the second epoxy resin are mixed, heated and melted, and mixed with 5-1200 parts by weight of the latent curing agent to obtain an epoxy resin matrix for prepreg, wherein the first epoxy resin and the second epoxy resin are the same or different. (3) The epoxy resin matrix is ​​coated and combined with reinforcing fibers or fabrics to obtain the high-toughness, high-modulus epoxy resin prepreg.

2. The method for preparing the high-toughness, high-modulus epoxy resin-based prepreg according to claim 1, characterized in that, In step (1), the amount of catalyst is 0.01-2% of the total mass of the first epoxy resin and the bisphenol compound; the molecular weight of the modified phenoxy resin is 5,000-50,000.

3. The method for preparing the high-toughness, high-modulus epoxy resin-based prepreg according to claim 1, characterized in that, The bisphenol compounds include at least one of bisphenol A, bisphenol F, bisphenol S, diallyl bisphenol A, and diallyl bisphenol S; the diamines include at least one of diaminodiphenylmethane, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, 2,2'-bis[4-(4-aminophenoxyphenyl)]propane, 1,3-bis(4'-aminophenoxy)benzene, and 1,4-bis(4'-aminophenoxy)benzene; the dianhydrides include at least one of bisphenol A type diether dianhydride, 3,3',4,4'-benzophenone tetracarboxylic dianhydride, 3,3',4,4'-diphenyl ether tetracarboxylic dianhydride, 2,3,3',4'-biphenyltetracarboxylic dianhydride, and 2,2'-bis(3,4-dicarboxyphenyl)hexafluoropropane tetracarboxylic dianhydride.

4. The method for preparing the high-toughness, high-modulus epoxy resin-based prepreg according to claim 1, characterized in that, The first epoxy resin includes at least one of bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin and bisphenol AD ​​type epoxy resin.

5. The method for preparing high-toughness, high-modulus epoxy resin-based prepreg according to claim 1, characterized in that, The catalyst includes at least one of quaternary ammonium salts, triphenylphosphine and its derivatives.

6. The method for preparing the high-toughness, high-modulus epoxy resin-based prepreg according to claim 1, characterized in that, The second epoxy resin includes at least one of bisphenol A glycidyl ether, bisphenol F glycidyl ether, o-cresol epoxy resin, glycidylamine epoxy resin, glycidyl ester epoxy resin, alicyclic epoxy resin, and phenolic epoxy resin.

7. The method for preparing high-toughness, high-modulus epoxy resin-based prepreg according to claim 1, characterized in that, The latent curing agent includes at least one of dicyandiamide, modified dicyandiamide, urea derivatives, and diaminodiphenyl sulfone.

8. The method for preparing high-toughness, high-modulus epoxy resin-based prepreg according to claim 1, characterized in that, The reinforcing fibers or fabrics include high-strength, high-modulus carbon fibers or fabrics.

9. A high-toughness, high-modulus epoxy resin-based prepreg, characterized in that, It is obtained by the preparation method described in any one of claims 1-8.

10. The application of the high-toughness, high-modulus epoxy resin-based prepreg according to claim 9 in aerospace structural materials and high-end sports equipment.

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