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

Abstract

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

Description

Technical Field

[0001] The present invention belongs to the field of preparation of composite materials, and particularly relates to a high-toughness and high-modulus epoxy resin-based prepreg and its preparation method and application. Background Art

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

[0003] Phenoxy resin, also called phenoloxy resin, poly(phenoloxy resin) or poly(hydroxy ether), has been studied as a common toughening agent for epoxy resins. For example, Chinese Patent CN106589826A discloses a phenoxy resin-epoxy resin premix and its preparation method, and a resin composition for carbon fiber prepreg and its preparation method. By reacting phenoxy resin with epoxy resin to increase the molecular weight, a premix of phenoxy resin is prepared. The epoxy resin for carbon fiber prepreg obtained thereby has excellent toughness, and the impact strength can reach 25.25 kJ / m 2 , however, due to the low modulus of phenoxy resin, the modulus of the matrix resin is not high, and the glass transition temperature (Tg) decreases. For another example, in "Study on the Properties of Novel Phenoxy Resins Containing Biphenyl Groups and Their Blended Composites", a tetramethylbiphenyl structure is introduced into phenoxy resin, thereby increasing the resistance to molecular chain rotation, and thus significantly improving the modulus and Tg of phenoxy resin (increased by nearly 59 °C compared with ordinary bisphenol A type phenoxy resin), but its toughness still cannot meet the requirements.

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

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

[0006] In the first aspect of the present invention, a preparation method of a high-toughness and high-modulus epoxy resin-based prepreg is provided, which includes the following steps:

[0007] (1) Reacting a bisphenol compound, a diamine and a dianhydride at 170-240 °C for 0.5-24 h, adding a first epoxy resin and a catalyst at 130-200 °C, and continuing the reaction 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) Mix the modified phenoxy resin and the second epoxy resin, heat and melt them, and then mix with a latent curing agent to obtain an epoxy resin matrix for prepreg, wherein the first epoxy resin and the second epoxy resin can be the same or different;

[0009] (3) Coat the epoxy resin matrix and pre-impregnate and compound with reinforcing fibers or fabrics to obtain the high-toughness and high-modulus epoxy resin-based prepreg.

[0010] In certain embodiments, according to the method for preparing a high-toughness and high-modulus epoxy resin-based prepreg of the present invention, wherein in step (1), the amount of the 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.

[0011] In certain embodiments, according to the method for preparing a high-toughness and high-modulus epoxy resin-based prepreg of the present invention, wherein 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 certain embodiments, according to the method for preparing a high-toughness and high-modulus epoxy resin-based prepreg of the present invention, wherein the first epoxy resin includes at least one of bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, and bisphenol AD epoxy resin.

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

[0014] In certain embodiments, according to the method for preparing a high-toughness and high-modulus epoxy resin-based prepreg of the present invention, wherein 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, for the method for preparing a high-toughness and high-modulus epoxy resin-based prepreg according to the present invention, the latent curing agent includes at least one of dicyandiamide, modified dicyandiamide, urea derivatives, and diaminodiphenyl sulfone.

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

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

[0018] A second aspect of the present invention provides a high-toughness and 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 present invention provides an application of the high-toughness and high-modulus epoxy resin-based prepreg described in the second aspect of the present invention in aerospace structural materials and high-end sports equipment.

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

[0021] (1) Using the general phenolic monomer of phenoxy resin as a solvent, modifying the phenoxy resin generated by the participation of phenolic monomers with the reaction product of diamine and dianhydride, realizing continuous synthesis and avoiding the treatment of intermediate products. Therefore, the process is reasonable and simple, and the use of highly polluting solvents such as DMAc is avoided.

[0022] (2) Introducing the high-rigidity molecule polyimide, while toughening the phenoxy resin, reducing the deformation of the cured crosslinking network, and increasing the modulus of the matrix resin; realizing interface enhancement between the high-rigidity resin matrix and high-strength and high-modulus carbon fiber, improving compatibility; effectively increasing the modulus of the composite material, and realizing the matching of epoxy resin and high-strength and high-modulus carbon fiber. Detailed Embodiments

[0023] Now, various exemplary embodiments of the present invention will be described in detail. This detailed description should not be considered as a limitation of the present invention, but should be understood as a more detailed description of certain aspects, characteristics, and embodiments of the present invention.

[0024] It should be understood that the terms used in this invention are only for describing particular embodiments and are not intended to limit the invention. Additionally, for the numerical ranges in this invention, it should be understood that the upper and lower limits of the range and each intermediate value therebetween are specifically disclosed. Intermediate values within any stated value or stated range, as well as each smaller range between any other stated value or intermediate value within the stated 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 specified, 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. Although this invention only describes preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the practice or testing of this invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials related to those documents. In case of conflict with any incorporated document, the content of this specification shall prevail.

[0026] Preparation method

[0027] In one aspect of this invention, a method for preparing a high-toughness and high-modulus epoxy resin-based prepreg is provided. In a preferred embodiment, the preparation method of this invention includes the following steps:

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

[0029] (2) Mix the modified phenoxy resin and a second epoxy resin, heat and melt them, and mix 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) Coating the epoxy resin matrix film and pre-impregnating and compounding it with reinforcing fibers or fabrics to obtain the high-toughness and high-modulus epoxy resin-based prepreg.

[0031] In step (1) of the present invention, the diamine and dianhydride preferably react in an inert gas. Examples of the inert gas include but are not limited to nitrogen, argon, etc. The first epoxy resin and the catalyst can be added simultaneously, or the first epoxy resin can be added first, and the catalyst can be added after reacting for a period of time (preferably 1-20 min, more preferably 5-15 min, such as 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 min).

[0032] In order 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, more preferably 140-220 g / mol, further preferably 160-200 g / mol, still 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] In order 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, more preferably 90-160 g / mol, further preferably 100-140 g / mol, still more preferably 100-120 g / mol, even more preferably 105-115 g / mol, such as 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 the epoxy resin-based prepreg, the viscosity of the modified phenoxy resin can be controlled to be 1 - 1,000,000 centipoises, preferably 5 - 950,000 centipoises, more preferably 10 - 900,000 centipoises, further preferably 15 - 850,000 centipoises, still more preferably 15 - 800,000 centipoises, such as 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 800,000 centipoises. In a preferred embodiment, the viscosity of the modified phenoxy resin is 700,000 centipoises. In another preferred embodiment, the viscosity of the modified phenoxy resin is 350,000 centipoises. In yet another preferred embodiment, the viscosity of the modified phenoxy resin is 150,000 centipoises.

[0035] To improve the toughness and modulus of the epoxy resin-based prepreg, the amounts of the bisphenol compound and the catalyst can be controlled within a suitable range. In the present invention, the amount of the bisphenol compound is 40 - 99% of the total mass of the initial materials (i.e., bisphenol compound, diamine, and dianhydride), preferably 40 - 95%, more preferably 40 - 90%, such as 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%, more preferably 0.1 - 1%, such as 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 a 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 the epoxy resin-based prepreg, the molecular weight of the polyimide can be controlled to be 1,500 - 30,000, such as 1,500, 5,000, 10,000, 15,000, 20,000, 25,000, 30,000, and the molecular weight of the modified phenoxy resin is 5,000 - 50,000, preferably 7,000 - 50,000, more preferably 9,000 - 50,000, such as 9,000, 10,000, 15,000, 20,000, 25,000, 30,000, 35,000, 40,000, 45,000, 50,000, or any value within the above range. In a 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 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.

[0039] In a 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 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 ether tetracarboxylic dianhydride.

[0040] In the present invention, the first epoxy resin includes bisphenol type epoxy resins, and the bisphenol type epoxy resins are not particularly limited. Examples thereof 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 bisphenol A epoxy resin.

[0041] In the present invention, the catalyst is not particularly limited, and examples thereof include, but are not limited to, quaternary ammonium salts, triphenylphosphine and its derivatives, etc. In a preferred embodiment, the catalyst is ethyltriphenylphosphonium bromide. In another preferred embodiment, the catalyst is triphenylphosphine. In yet another preferred embodiment, the catalyst is tetrabutylammonium bromide.

[0042] In the present invention, the second epoxy resin is not particularly limited, and examples thereof 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 the present invention, the latent curing agent is not particularly limited, and examples thereof 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 the present invention, the reinforcing fiber or fabric is not particularly limited, and examples thereof include, but are not limited to, high-strength and high-modulus carbon fiber or fabric, such as MX grade, MJ grade, TG grade carbon fiber or fabric, etc.

[0045] In the present invention, a general phenolic monomer (such as bisphenol compounds) of phenoxy resin is used as a solvent, and a diamine and a dianhydride are used as reaction raw materials to synthesize polyimide. Then, a bisphenol type epoxy resin is added to react with the bisphenol compound to synthesize phenoxy resin, obtaining a polyimide-modified phenoxy resin, realizing the continuous synthesis of the modified phenoxy resin, avoiding the treatment of intermediate products, and also avoiding highly polluting solvents such as DMAc required in the traditional synthesis of polyimide. The molecular weight of the polyimide is preferably 1,500 - 30,000, and the molecular weight of the modified phenoxy resin is preferably 5,000 - 50,000.

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

[0047] In one aspect of the present invention, there is provided a high-toughness and high-modulus epoxy resin-based prepreg obtained by the preparation method of the present invention.

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

[0049] In the present invention, the tensile modulus and toughness of the epoxy resin-based prepreg can be determined by methods and apparatuses known in the art, and no particular limitation is imposed thereon. In a preferred embodiment, the high-toughness and high-modulus epoxy resin-based prepreg of the present invention has a tensile modulus of not less than 200 GPa and a fracture toughness of not less than 709 J / m 2 2.

[0050] Application

[0051] In one aspect of the present invention, there is provided the use of the high-toughness and high-modulus epoxy resin-based prepreg 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 (such as, but not limited to, wing spars, wing boxes, wing ribs, etc.), secondary load-bearing structures (such as, but not limited to, fairings, hatches, control surfaces, etc.), engine components (such as, but not limited to, fan blades, nacelle linings, etc.), spacecraft structures (such as, but not limited to, detector structures, fuel tanks, etc.), and the like. Examples of the high-end sports equipment include, but are not limited to, racing cars, mountain bikes, tennis rackets, golf clubs, snowboards, ski poles, hockey sticks, rowing boats, surfboards, and the like.

[0052] Example 1

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

[0054] (1) In a reaction kettle, accurately add 509.1 grams of diamine 1,3-bis(4'-aminophenoxy)benzene (TPE-R), 502.7 grams of 2,3,3',4-biphenyltetracarboxylic dianhydride (α-BPDA), and 1011.8 grams of bisphenol A. Under nitrogen protection, heat the materials to 230 °C and react for 4 hours. At this time, the viscosity is 700,000 centipoises (constant temperature at 120 °C for 30 minutes); lower the system temperature to 200 °C, accurately add 1700.7 grams of bisphenol A epoxy resin (NPEL128 of Nan Ya Plastics Industry Co., Ltd., epoxy equivalent 186.5 g / mol). After reacting for 10 minutes, add 3.7 grams of catalyst ethyltriphenylphosphonium bromide and react for 4 h. At this time, the viscosity is 700,000 centipoises (constant temperature at 150 °C for 30 minutes), and then discharge to obtain the modified phenoxy resin. Among them, the amount of bisphenol solvent is 50% of the total mass of the initial materials, and the molecular weight of the modified phenoxy resin is 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 epoxy resin (Syna-Epoxy 720 of Nantong Xinaxi New Materials Co., Ltd., epoxy equivalent 110.2 g / mol) and dissolve it evenly to prepare an epoxy resin matrix for prepreg with 30 phr of diaminodiphenylsulfone (DDS) as the curing agent;

[0056] (3) Coating the above resin matrix film and compounding it with M40X carbon fiber to obtain a high toughness and high modulus epoxy resin-based prepreg;

[0057] (4) Cutting, laying, and molding the obtained prepreg to obtain an epoxy / carbon fiber composite material.

[0058] Example 2

[0059] The following shows the preparation method of a high toughness and high modulus epoxy resin-based prepreg and its composite material.

[0060] (1) In a reaction kettle, accurately add 278.3 grams of diamine 2,2'-bis[4-(4-aminophenoxyphenyl)]propane (BAPP), 501.3 grams of bisphenol A diether dianhydride (BPADA), and 1169.4 grams of diallyl bisphenol A. Under nitrogen protection, heat the materials to 180 °C and react for 20 hours. At this time, the viscosity is 250,000 centipoises (constant temperature at 120 °C for 30 minutes); lower the system temperature to 180 °C, accurately add 2370.6 grams of bisphenol A epoxy resin (NPEL128 of Nan Ya Plastics Industry Co., Ltd., epoxy equivalent 186.5 g / mol). After reacting for 10 minutes, add 4.3 grams of catalyst triphenylphosphine and react for 10 h. At this time, the viscosity is 350,000 centipoises (constant temperature at 150 °C for 30 minutes), and discharge to obtain a modified phenoxy resin. Among them, the amount of bisphenol solvent is 40% of the total mass of the initial materials, and the molecular weight of the modified phenoxy resin is 10,000;

[0061] (2) Add 5 phr (parts by weight, the same below) of the above modified phenoxy resin to 100 phr of tetraglycidylamine epoxy resin (Syna-Epoxy 720 of Nantong Xinaxi New Materials Co., Ltd., epoxy equivalent 110.2 g / mol) and dissolve evenly to prepare an epoxy resin matrix for prepreg with 30 phr of diaminodiphenyl sulfone as the curing agent;

[0062] (3) Coating the above resin matrix film and compounding it with M40X carbon fiber to obtain a high toughness and high modulus epoxy resin-based prepreg;

[0063] (4) Cutting, laying, and molding the obtained prepreg to obtain an epoxy / carbon fiber composite material.

[0064] Example 3

[0065] The following shows the preparation method of a high toughness and high modulus epoxy resin-based prepreg and its composite material.

[0066] (1) In a reaction kettle, accurately add 328.1 grams of diamine 4,4'-diaminodiphenyl ether (ODA), 500.1 grams of 3,3',4,4'-diphenyl ether tetracarboxylic dianhydride (ODPA), 16.7 grams of catalyst benzimidazole, and 7604.1 grams of diallyl bisphenol A. Under nitrogen protection, heat the materials to 190 °C and react for 8 hours. At this time, the viscosity is 80,000 centipoises (constant temperature at 120 °C for 30 minutes); lower the system temperature to 150 °C, add 3834.5 grams of bisphenol A epoxy resin (NPEL128 of Nan Ya Plastics Industry Co., Ltd., epoxy equivalent 186.5 g / mol). After reacting for 10 minutes, add 24.5 grams of catalyst tetrabutylammonium bromide and react for 5 hours. At this time, the viscosity is 150,000 centipoises (constant temperature at 150 °C for 30 minutes), and then discharge to obtain the modified phenoxy resin. Among them, the amount of bisphenol solvent is 90% of the total mass of the initial materials, 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 tetrafunctional glycidylamine epoxy resin (Syna-Epoxy 720 of Nantong Xinaxi New Materials Co., Ltd., epoxy equivalent 110.2 g / mol) and dissolve it evenly to prepare an epoxy resin matrix for prepreg with 30 phr of diaminodiphenyl sulfone as the curing agent;

[0068] (3) Coat the above resin matrix and compound it with M40X carbon fiber to obtain a high-toughness and high-modulus epoxy resin-based prepreg;

[0069] (4) Cut, lay up, and mold the obtained prepreg to obtain an epoxy / carbon fiber composite material.

[0070] Comparative Example 1

[0071] The following shows the preparation methods of epoxy resin-based prepregs and their composite materials.

[0072] (1) Add 5 phr of phenoxy resin (PKHH of Union Carbide) to 100 phr of tetrafunctional glycidylamine epoxy resin (Syna-Epoxy 720 of Nantong Xinaxi New Materials Co., Ltd., epoxy equivalent 110.2 g / mol) in a reaction kettle and dissolve it evenly to prepare an epoxy resin matrix for prepreg with 30 phr of diaminodiphenyl sulfone as the curing agent;

[0073] (2) Coat the above resin matrix and compound it with M40X carbon fiber to obtain an epoxy resin prepreg;

[0074] (3) Cut, lay up, and mold the obtained prepreg to obtain an epoxy / carbon fiber composite material.

[0075] Comparative Example 2

[0076] The preparation methods of epoxy resin-based prepregs and their composites are shown below.

[0077] (1) Add 5 phr of a polyimide and phenoxy resin mixture (polyimide SK0180 from Changzhou Shangke New Materials Co., Ltd. and phenoxy resin PKHH from Union Carbide of the United States, with SK0180 accounting for 25.1%) to 100 phr of a tetrafunctional glycidyl amine epoxy resin (Syna-Epoxy 720 from Nantong Xinaxi New Materials Co., Ltd., epoxy equivalent 110.2 g / mol) in a reaction kettle and melt them evenly. Use 30 phr of diaminodiphenyl sulfone as the curing agent to prepare the epoxy resin matrix for the prepreg.

[0078] (2) Coating the above resin matrix and compounding it with M40X carbon fiber to obtain an epoxy resin prepreg.

[0079] (3) Cut, layer, and mold the obtained prepreg to obtain an epoxy / carbon fiber composite.

[0080] Test the properties of the composites in Examples 1-3 and Comparative Examples 1-2. Among them, the tensile modulus of the composite is obtained by testing with an Instron-1121 universal material testing machine from the United States, and the test standard is GB 3354; the interlaminar fracture toughness of the composite is obtained by testing with an Instron-1121 universal material testing machine from the United States, and the test standard is HB 7402. The test results are shown in Table 1.

[0081] Table 1 Properties of different composites

[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, but also improves its modulus.

[0084] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features. And these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A preparation method of a high-toughness and high-modulus epoxy resin-based prepreg, characterized in that, It includes the following steps: (1) React a bisphenol compound, a diamine and a dianhydride at 170 - 240 °C for 0.5 - 24 h, add a first epoxy resin and a catalyst at 130 - 200 °C, and continue to react 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) Mix the modified phenoxy resin and a second epoxy resin, heat and melt them, and mix with a 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) Coat the epoxy resin matrix and composite it with a reinforcing fiber or fabric to obtain the high-toughness and high-modulus epoxy resin-based prepreg.

2. The preparation method of the high-toughness and high-modulus epoxy resin-based prepreg according to claim 1, characterized in that, In step (1), the amount of the 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 preparation method of the high-toughness and high-modulus epoxy resin-based prepreg according to claim 1, wherein 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.

4. The preparation method of the high-toughness and high-modulus epoxy resin-based prepreg according to claim 1, wherein, 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 preparation method of the high-toughness and 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 preparation method of the high-toughness and 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 novolac epoxy resin.

7. The preparation method of the high-toughness and 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 preparation method of the high-toughness and high-modulus epoxy resin-based prepreg according to claim 1, wherein, The reinforcing fiber or fabric includes high-strength and high-modulus carbon fiber or fabric.

9. A high-toughness and 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. Application of the high-toughness and high-modulus epoxy resin-based prepreg according to claim 9 in aerospace structural materials and high-end sports equipment.

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