High-temperature-resistant multi-scale synergistically toughened epoxy resin, and preparation method and application thereof

Abstract

The application belongs to the technical field of epoxy resin modification, and discloses a high-temperature-resistant multi-scale synergistically toughened epoxy resin and a preparation method and application thereof.The high-temperature-resistant multi-scale synergistically toughened epoxy resin comprises the following raw materials in mass fractions: 80-110 parts of epoxy resin; 80-100 parts of a curing agent; and 5-20 parts of toughening particles.Through regulating and controlling the molecular structures and particle morphologies of the two kinds of toughening particles and the matching of the toughening particles of various scales, the advantages of the two kinds of toughening particles can be exerted, and the toughening effect can be synergistically exerted, so that an epoxy resin system with high toughness, low viscosity at pouring temperature and meeting the requirements of liquid molding process is obtained, and the epoxy resin system is suitable for manufacturing large-sized civil aviation main load-bearing structure composites with complex structures by using dry fiber automatic laying liquid molding process.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of epoxy resin modification, and particularly relates to a high-temperature-resistant multi-scale synergistically toughened epoxy resin and a preparation method and application thereof. BACKGROUND

[0002] High-performance resin matrix composites have outstanding characteristics such as high specific strength, high specific modulus and excellent forming adaptability, and are widely used in advanced manufacturing fields such as aerospace. Taking the aviation field as an example, whether for military or civil aircraft, the amount of high-performance resin matrix composites is rapidly increasing, and the amount is even regarded as one of the indicators of the advancement of aircraft. For example, the lightweight composite material is selected to replace the traditional metal material in the fuselage part of Boeing 787 and Airbus A350 passenger aircraft, and about 50% of the weight of the entire Boeing 787 passenger aircraft comes from the composite material, greatly reducing the weight of the entire aircraft.

[0003] In recent years, due to the advantages of low design and manufacturing cost, precise control of part size, large degree of freedom of operation, and suitability for integrated manufacturing of complex structures, liquid molding technology is gradually becoming the focus of research and development in the field of aviation composite manufacturing. However, when the resin matched with the liquid molding is a highly cross-linked thermosetting epoxy resin, the brittle nature of the epoxy resin makes it difficult for the epoxy-based composite material to meet the damage tolerance requirements of the main load-bearing composite material components of civil aviation. On the other hand, the size of the main load-bearing structure composite material of civil aviation is too large, and when it is manufactured by liquid molding process, a long process window and a low resin viscosity are required, and the viscosity at the pouring temperature should not exceed 300 mPa.s and should be maintained for more than 5 hours. Therefore, in the liquid molding epoxy resin system, due to the dual restrictions of the viscosity requirements of the pouring process and the fiber filtration effect, the conventional prepreg resin toughening method is almost not applicable, which directly leads to the lack of such high-performance liquid molding epoxy resin.

[0004] So far, the development and modification of liquid molding epoxy resin has been one of the focuses of research at home and abroad, and the use of thermoplastic polymer particles and core-shell particles has been proven to effectively improve the toughness of the epoxy resin. However, the use of thermoplastic polymer particles alone will cause the viscosity of the resin system to increase sharply, which cannot meet the needs of the liquid molding process; and the addition of core-shell particles alone will reduce the strength and modulus of the matrix resin. The use of thermoplastic polymer particles and core-shell particles alone cannot meet the needs of the liquid molding process and the mechanical properties. SUMMARY

[0005] The present application aims to provide a high-temperature-resistant multi-scale synergistically toughened epoxy resin and a preparation method and application thereof, which solves the problem that the existing epoxy resin cannot meet the needs of the liquid molding process and the mechanical properties.

[0006] To achieve the above object, the present application provides the following technical solutions.

[0007] The present application provides a high-temperature-resistant multi-scale synergistically toughened epoxy resin, comprising the following raw materials in mass fraction:

[0008] Epoxy resin 80-110 parts;

[0009] Curing agent 80-100 parts;

[0010] Toughening particles 5-20 parts;

[0011] The epoxy resin comprises a mixture of a trifunctional epoxy resin and a tetrafunctional epoxy resin.

[0012] The toughening particles comprise a mixture of core-shell particles and thermoplastic polymer particles.

[0013] Preferably, in the high-temperature-resistant multi-scale synergistically toughened epoxy resin, the trifunctional epoxy resin comprises one or two of 4,5-epoxycyclohexane-1,2-dicarboxylic acid diglycidyl ester, m-aminophenol triglycidyl epoxy resin, and p-aminophenol triglycidyl epoxy resin.

[0014] The tetrafunctional epoxy resin comprises 3,3'-diethyl-4,4'-diamino diphenyl methane tetraglycidyl amine and / or 4,4'-diamino diphenyl methane tetraglycidyl amine epoxy resin.

[0015] Preferably, in the high-temperature-resistant multi-scale synergistically toughened epoxy resin, the curing agent comprises 4,4'-methylene bis-(3-chloro-2,6-diethyl aniline) and / or 3,3'-dichloro-4,4'-diamino diphenyl methane.

[0016] Preferably, in the high-temperature-resistant multi-scale synergistically toughened epoxy resin, the particle size of the core-shell particles is 80-200 nm.

[0017] Preferably, in the high-temperature-resistant multi-scale synergistically toughened epoxy resin, the inner core of the core-shell particles is an acrylate soft monomer polymer.

[0018] The acrylate soft monomer used in the acrylate soft monomer polymer comprises one or more of isooctyl acrylate, ethyl acrylate, lauryl acrylate, butyl acrylate, 2-ethylhexyl acrylate, and lauryl methacrylate.

[0019] The shell of the core-shell particles is an acrylate hard monomer polymer.

[0020] The acrylate hard monomer used in the acrylate hard monomer polymer includes one or more of methyl acrylate, acrylonitrile, methyl methacrylate, acrylamide, and styrene.

[0021] Preferably, in the high-temperature-resistant multi-scale synergistically toughened epoxy resin, the particle size of the thermoplastic polymer particles is 0.5-2 μm.

[0022] The thermoplastic polymer particles include one or more of polyether sulfone, polyamide, polyetherimide, and polyether ether ketone.

[0023] Preferably, in the high-temperature-resistant multi-scale synergistically toughened epoxy resin, the mass ratio of the core-shell particles to the thermoplastic polymer particles is 1:2-2:1.

[0024] The application further provides a preparation method of the high-temperature-resistant multi-scale synergistically toughened epoxy resin, including the following steps:

[0025] (1) mixing the core-shell particles and the trifunctional epoxy resin by using a phase transfer method, the mass ratio of the core-shell particles to the trifunctional epoxy resin being 1:3-4, to obtain a first mixture;

[0026] (2) mixing the tetrafunctional epoxy resin, the remaining trifunctional epoxy resin, and the thermoplastic polymer particles to obtain a second mixture;

[0027] (3) mixing the first mixture, the second mixture, and a curing agent to obtain the high-temperature-resistant multi-scale synergistically toughened epoxy resin;

[0028] The steps (1) and (2) have no order limitation.

[0029] Preferably, in the preparation method of the high-temperature-resistant multi-scale synergistically toughened epoxy resin, in the step (3), the mixing conditions of the first mixture, the second mixture, and the curing agent include: the mixing temperature is 90-120 ℃, and the mixing time is 40-60 min.

[0030] The application further provides an application of the high-temperature-resistant multi-scale synergistically toughened epoxy resin in liquid molding manufacturing of a composite material.

[0031] According to the above technical solution, compared with the prior art, the application has the following beneficial effects:

[0032] The high-temperature-resistant multi-scale synergistic toughening epoxy resin provided by the application can play the advantages of the two kinds of toughening particles by regulating the molecular structure and particle morphology of the two kinds of toughening particles and the ratio of the toughening particles of each scale. The micron-level thermoplastic polymer particles and the nanometer-level core-shell particles are dispersed in the matrix epoxy resin in the form of molecules and particles respectively, and neither of the two kinds of toughening particles can be filtered by the fibers and can permeate around the fibers with the matrix resin. With the progress of the curing reaction, the thermoplastic polymer particles and the core-shell particles are uniformly distributed in the composite material in the form of particles of different scales, and the multi-scale synergistic toughening technology is used to synergistically play the toughening effect.

[0033] In addition, neither of the two kinds of toughening particles and the matrix epoxy resin can react chemically, and the chemical reaction characteristics of the matrix resin are not affected, and the operation time and storage period of the resin are not shortened. The nanometer-level core-shell particles are always dispersed in the epoxy resin in the form of particles during the entire liquid molding process, and have very little effect on the increase in viscosity. The micron-level thermoplastic polymer particles are dissolved in the epoxy resin in the form of molecules. Although the micron-level thermoplastic polymer particles contribute slightly more to the increase in the viscosity of the matrix resin, the influence of the thermoplastic polymer particles on the overall resin viscosity is reduced due to the regulation of the specific ratio of the two kinds of toughening particles, and the resin can still maintain low viscosity and long process window at the infusion temperature.

[0034] In summary, the application obtains an epoxy resin system with high-temperature resistance, high toughness, low viscosity at the infusion temperature and meeting the requirements of the liquid molding process, which is suitable for the automatic dry fiber placement liquid molding process to manufacture complex structure and large-size civil aviation main load-bearing structure composites. DETAILED DESCRIPTION

[0035] The application provides a high-temperature-resistant multi-scale synergistic toughening epoxy resin, which comprises the following raw materials in mass fraction:

[0036] 80-110 parts of epoxy resin;

[0037] 80-100 parts of curing agent;

[0038] 5-20 parts of toughening particles;

[0039] The epoxy resin comprises a mixture of trifunctional epoxy resin and tetrafunctional epoxy resin.

[0040] The toughening particles comprise a mixture of core-shell particles and thermoplastic polymer particles.

[0041] In the present application, the trifunctional epoxy resin preferably includes one or two of 4,5-epoxycyclohexane-1,2-dicarboxylic acid diglycidyl ester (CAS: 25293-64-5), m-aminophenol triglycidyl epoxy resin (CAS: 71604-74-5), p-aminophenol triglycidyl epoxy resin (CAS: 5026-74-4), further preferably includes m-aminophenol triglycidyl epoxy resin and / or p-aminophenol triglycidyl epoxy resin, and more preferably includes m-aminophenol triglycidyl epoxy resin and p-aminophenol triglycidyl epoxy resin.

[0042] In the present application, the tetrafunctional epoxy resin preferably includes 3,3'-diethyl-4,4'-diaminodiphenylmethane tetraglycidyl amine (CAS: 130728-76-6) and / or 4,4'-diaminodiphenylmethane tetraglycidyl amine epoxy resin (CAS: 28768-32-3), and further preferably includes 4,4'-diaminodiphenylmethane tetraglycidyl amine epoxy resin.

[0043] In the present application, the mass ratio of the trifunctional epoxy resin to the tetrafunctional epoxy resin is preferably any ratio.

[0044] In the present application, when the trifunctional epoxy resin or the tetrafunctional epoxy resin is preferably two, the ratio between various types of epoxy resins is not limited, and any ratio can be used.

[0045] In the present application, the mass fraction of the epoxy resin is preferably 85 to 105 parts, further preferably 90 to 100 parts, and more preferably 100 parts.

[0046] In the present application, the curing agent preferably includes 4,4'-methylenebis-(3-chloro-2,6-diethylaniline) (CAS: 106246-33-7) and / or 3,3'-dichloro-4,4'-diaminodiphenylmethane (CAS: 101-14-4), and further preferably includes 4,4'-methylenebis-(3-chloro-2,6-diethylaniline).

[0047] In the present application, when the curing agent is preferably two, the ratio between various types of curing agents is not limited, and any ratio can be used.

[0048] In the present application, the mass fraction of the curing agent is preferably 85 to 98 parts, further preferably 90 to 96 parts, and more preferably 96 parts.

[0049] In the present application, the particle size of the core-shell particle is preferably 80 to 200 nm, further preferably 100 to 160 nm, and more preferably 100 to 120 nm. In the present application, the particle size of the core-shell particle is preferably 80 to 200 nm, further preferably 100 to 160 nm, and more preferably 100 to 120 nm.

[0050] In the present application, the inner core of the core-shell particle is preferably an acrylate soft monomer polymer.

[0051] In the present application, the acrylate soft monomer used in the acrylate soft monomer polymer preferably includes one or more of isooctyl acrylate, ethyl acrylate, lauryl acrylate, butyl acrylate, 2-ethylhexyl acrylate, lauryl methacrylate, further preferably one or more of isooctyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, and more preferably isooctyl acrylate.

[0052] In the present application, the shell of the core-shell particle is preferably an acrylate hard monomer polymer.

[0053] In the present application, the acrylate hard monomer used in the acrylate hard monomer polymer preferably includes one or more of methyl acrylate, acrylonitrile, methyl methacrylate, acrylamide, styrene, further preferably one or more of methyl acrylate, methyl methacrylate, acrylamide, and more preferably methyl methacrylate.

[0054] In the present application, when the acrylate soft monomer or the acrylate hard monomer is multiple, the ratio between the various types is not limited, and any ratio can be used.

[0055] In the present application, the preparation method of the core-shell particle is preferably emulsion polymerization, suspension polymerization or solution polymerization, further preferably emulsion polymerization.

[0056] In the present application, the method of emulsion polymerization is not limited, and details are referred to the Chinese patent application with the publication number CN118271792A and the patent name “Toughening and reinforcing type nano core-shell particle toughening agent, its preparation method and application”.

[0057] In the present application, the particle size of the thermoplastic polymer particle is preferably 0.5-2 μm, further preferably 0.8-1.5 μm, and more preferably 1-1.2 μm.

[0058] In the present application, the thermoplastic polymer particle preferably includes one or more of polyether sulfone, polyamide, polyether imide, polyether ether ketone, further includes polyether sulfone, polyamide, polyether imide or polyether ether ketone, and more preferably polyether sulfone.

[0059] In the present application, the weight average molecular weight of the polyether sulfone, the polyamide, the polyether imide, the polyether ether ketone is not limited, and products well known to those skilled in the art can be used.

[0060] In the present application, the thermoplastic polymer particles are preferably multiple, and the ratio between various types is not limited, and any ratio can be used.

[0061] In the present application, the mass ratio of the core-shell particles to the thermoplastic polymer particles is preferably 1:2 to 2:1, further preferably 1:1 to 2:1, and more preferably 1.6:1 to 1.8:1.

[0062] In the present application, the mass fraction of the toughening particles is preferably 6 to 18 parts, further preferably 8 to 16 parts, and more preferably 14 to 16 parts.

[0063] The present application also provides a preparation method of a high-temperature-resistant multi-scale synergistic toughening epoxy resin, comprising the following steps:

[0064] (1) mixing core-shell particles and a trifunctional epoxy resin by a phase transfer method, the mass ratio of the core-shell particles to the trifunctional epoxy resin being 1:3 to 4, to obtain a first mixture;

[0065] (2) mixing a tetrafunctional epoxy resin, the remaining trifunctional epoxy resin, and thermoplastic polymer particles to obtain a second mixture;

[0066] (3) mixing the first mixture, the second mixture, and a curing agent to obtain a high-temperature-resistant multi-scale synergistic toughening epoxy resin;

[0067] Wherein, steps (1) and (2) have no order limitation.

[0068] In the present application, in step (1), the mass ratio of the core-shell particles to the trifunctional epoxy resin is preferably 1:3 to 3.8, further preferably 1:3 to 3.5, and more preferably 1:3 to 3.2.

[0069] In the present application, the phase transfer method in step (1) is not limited, and details are referred to the Chinese patent application with publication number CN118271792A and patent name "Toughening and reinforcing type nano core-shell particle toughening agent and its preparation method and application".

[0070] In the present application, in step (2), the mixing method of the tetrafunctional epoxy resin, the remaining trifunctional epoxy resin, and the thermoplastic polymer particles is preferably:

[0071] The tetrafunctional epoxy resin and the remaining trifunctional epoxy resin are first mixed, and the thermoplastic polymer particles are added for second mixing.

[0072] In the present application, the temperature of the first mixing is preferably 75 to 85°C, further preferably 78 to 82°C, and more preferably 80°C.

[0073] In the present application, the temperature of the second mixing is preferably 90-130℃, further preferably 115-125℃, and more preferably 120℃.

[0074] In the present application, the time for the first mixing and the time for the second mixing are not limited, as long as the mixing is even.

[0075] In the present application, in step (3), the way of mixing the first mixture, the second mixture and the curing agent is preferably: mixing the first mixture and the second mixture to form a third mixture, and adding the curing agent to the third mixture to form a fourth mixture.

[0076] In the present application, the temperature of the third mixing is preferably 80-90℃, further preferably 80-85℃, and more preferably 80℃. The time for the third mixing is not limited, as long as the mixing is even.

[0077] In the present application, in step (3), the conditions of mixing the first mixture, the second mixture and the curing agent include: the mixing temperature is preferably 90-120℃, further preferably 95-110℃, and more preferably 100℃; and the mixing time is preferably 40-60min, further preferably 50-60min, and more preferably 60min.

[0078] The present application also provides an application of the high-temperature-resistant multi-scale synergistically toughened epoxy resin in liquid molding manufacturing of composite materials.

[0079] In the present application, the method for the application is not limited, and the method known to those skilled in the art can be used.

[0080] The technical solutions in the embodiments of the present application will be described clearly and completely below. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0081] Embodiment 1

[0082] The present embodiment provides a preparation method of a high-temperature-resistant multi-scale synergistically toughened epoxy resin, comprising the following steps:

[0083] (1) In a reaction kettle, 200 parts of water and 3.75 parts of sodium dodecyl benzene sulfonate were added, and the temperature was raised to 70°C, and stirring was started. After 30 minutes, 4 parts of a mixture of isooctyl acrylate and 0.2 parts of ethylene glycol dimethacrylate was added dropwise into the reaction kettle, and 5 parts of 5wt% ammonium persulfate-sodium methyl sulfinate initiation system was added to initiate the formation of a certain amount of seed emulsion. After 1 hour, 76 parts of a mixture of isooctyl acrylate and 3.8 parts of ethylene glycol dimethacrylate core layer monomer, 80 parts of methyl methacrylate and 4 parts of ethylene glycol dimethacrylate shell layer monomer were added dropwise at a constant rate for 3 hours. The shell layer monomer mixture was added after the core layer monomer mixture. At the same time, 10 parts of 5wt% initiation system was added dropwise at a constant rate. After the completion of the addition of the initiation system, the temperature was maintained at 70°C for 1.5 hours, and then the natural cooling was carried out. After the filtration through a 200 mesh screen, the product was placed in a storage tank for subsequent use. The particle size of the obtained core-shell particles was 100-120nm.

[0084] (2) 80g of butanone was added to a 300mL beaker, then 50g of the core-shell particle emulsion prepared above was added and stirred to mix uniformly, then 25g of water was added and stirred. After 30 minutes, the stirring was stopped, and the mixture was left to stand at room temperature for 1 hour to form a clear layer. The lower water layer was filtered. Then 40g of m-aminophenol triglycidyl epoxy resin was added to the organic solvent containing the nanoparticles, and the solvent was removed by distillation under reduced pressure to obtain a core-shell particle-m-aminophenol triglycidyl epoxy resin dispersion. The mass ratio of the epoxy resin to the core-shell particle in the dispersion was 3:1. The dispersion was named as the first mixture.

[0085] (3) 20 parts of 4,4'-diamino diphenyl methane tetraglycidyl amine epoxy resin, 40 parts of p-aminophenol triglycidyl epoxy resin and 10 parts of m-aminophenol triglycidyl epoxy resin were mixed at 80°C, then 6 parts of thermoplastic polyether sulfone PES polymer particles (weight average molecular weight 55000, particle size 1-1.2μm) were added, and the mixture was stirred at 120°C until the thermoplastic polymer particles were completely dissolved to obtain a second mixture.

[0086] (4) 40 parts of the first mixture and the second mixture obtained in step (3) were mixed at 80°C, and 96 parts of 4,4'-methylene bis-(3-chloro-2,6-diethyl aniline) curing agent was slowly added, and the mixture was stirred at 100°C for 60 minutes to obtain a high temperature resistant multi-scale synergistically toughened epoxy resin.

[0087] The epoxy resin composition obtained in Example 1 was placed in a vacuum oven at 80°C to eliminate the air bubbles in the resin. The resin composition was poured into a mold, and placed in an oven at 180°C for curing for 3 hours. After the completion of the curing, the oven switch was turned off to allow the natural cooling to room temperature to form an epoxy resin cured product.

[0088] The epoxy resin composition obtained in Example 1 has a viscosity of 202 mPa.s at the working temperature of the liquid molding resin (100°C) and an operation time of 9.5 h.

[0089] The tensile strength of the cured product of the epoxy resin obtained in Example 1 is 93.8 MPa and the tensile modulus is 3.3 GPa, which are tested according to the standard of ASTM D638. The fracture toughness of the cured product of the epoxy resin obtained in Example 1 is 1.29 MPa.m 1 / 2 , and the glass transition temperature obtained by DMA test is 196°C.

[0090] Example 2

[0091] The present embodiment provides a preparation method of a high-temperature-resistant multi-scale synergistically toughened epoxy resin, comprising the following steps:

[0092] (1) Core-shell particles are prepared by using isooctyl acrylate as the core and methyl methacrylate as the shell by emulsion polymerization, and the preparation method is the same as the scheme of step (1) of Example 1, and the particle size of the core-shell particles is 100-120 nm;

[0093] (2) The core-shell particles in the water phase are transferred into the m-aminophenol triglycidyl epoxy resin by phase transfer technology, and the mass ratio of the epoxy resin to the core-shell particles is 3:1, and the method is the same as the scheme of step (2) of Example 1, to obtain a first mixture;

[0094] (3) 20 parts of 4,4'-diamino diphenyl methane tetraglycidyl amine epoxy resin, 40 parts of p-aminophenol triglycidyl epoxy resin and 10 parts of m-aminophenol triglycidyl epoxy resin are mixed at 80°C, then 10 parts of thermoplastic PES polymer particles (weight average molecular weight 55000, particle size 1-1.2 μm) are added, and the mixture is stirred at 120°C until the thermoplastic polymer particles are completely dissolved, to obtain a second mixture;

[0095] (4) 40 parts of the first mixture and the second mixture obtained in step (3) are mixed at 80°C, 96 parts of 4,4'-methylene bis-(3-chloro-2,6-diethyl aniline) curing agent are slowly added, and the mixture is stirred at 100°C for 60 min, to obtain a high-temperature-resistant multi-scale synergistically toughened epoxy resin.

[0096] The composition of the epoxy resin obtained in Example 2 is placed in a vacuum oven at 80°C to eliminate bubbles in the resin; the resin composition is poured into a mold and placed in an oven at 180°C for curing for 3 h, and after curing is completed, the oven switch is turned off to naturally cool to room temperature to form an epoxy resin cured product.

[0097] The epoxy resin composition obtained in Example 2 has a viscosity of 480 mPa.s at the working temperature of the liquid molding resin (100°C) and an operation time of 8.4 h.

[0098] The tensile strength of the cured product of the epoxy resin obtained in Example 2 is 92.9 MPa, the tensile modulus is 3.4 GPa, the fracture toughness is 1.41 MPa.m 1 / 2 , and the glass transition temperature is 196°C.

[0099] Comparative Example 1

[0100] This comparative example provides a method for preparing an epoxy resin, comprising the following steps:

[0101] 20 parts of 4,4'-diaminodiphenylmethane tetraglycidyl amine epoxy resin, 40 parts of p-aminophenol triglycidyl epoxy resin and 40 parts of m-aminophenol triglycidyl epoxy resin are mixed at 80°C, 96 parts of 4,4'-methylenebis-(3-chloro-2,6-diethyl aniline) curing agent is slowly added thereto, and the mixture is stirred at a temperature of 100°C for 60 min to obtain an epoxy resin.

[0102] The composition of the epoxy resin obtained in Comparative Example 1 is placed in a vacuum oven at 80°C to eliminate bubbles in the resin; the resin composition is poured into a mold and placed in an oven at 180°C for curing for 3 h, and after curing is completed, the oven switch is turned off to allow it to cool naturally to room temperature to form an epoxy resin cured product.

[0103] The epoxy resin composition obtained in Comparative Example 1 has a viscosity of 57 mPa.s at the working temperature of the liquid molding resin (100°C) and an operation time of 13.7 h.

[0104] The tensile strength of the cured product of the epoxy resin obtained in Comparative Example 1 is 77.7 MPa, the tensile modulus is 3.7 GPa, the fracture toughness is 0.70 MPa.m 1 / 2 , and the glass transition temperature is 194°C.

[0105] Comparative Example 2

[0106] This comparative example provides a method for preparing a toughened epoxy resin, comprising the following steps:

[0107] (1) Core-shell particles are prepared with isooctyl acrylate as the core and methyl methacrylate as the shell by emulsion polymerization, and the preparation method is the same as that of step (1) of Example 1, and the particle size of the core-shell particles is 100-120 nm.

[0108] (2) The core-shell particles in the water phase were transferred into the m-aminophenol triglycidyl epoxy resin by phase transfer technology, the mass ratio of the epoxy resin to the core-shell particles was 3:1, the method was the same as the scheme of step (2) of Example 1, to obtain a first mixture;

[0109] (3) 20 parts of 4,4'-diamino diphenyl methane tetraglycidyl amine epoxy resin, 40 parts of p-aminophenol triglycidyl epoxy resin and 10 parts of m-aminophenol triglycidyl epoxy resin were mixed at 80°C to obtain a second mixture;

[0110] (4) 40 parts of the first mixture and the second mixture obtained in step (3) were mixed at 80°C, 96 parts of 4,4'-methylene bis-(3-chloro-2,6-diethyl aniline) curing agent was slowly added, the temperature was raised to 100°C and mixed for 60 min under stirring to obtain a toughened epoxy resin.

[0111] The composition of the epoxy resin obtained in Comparative Example 2 was placed in a vacuum oven at 80°C to eliminate bubbles in the resin; the resin composition was poured into a mold and placed in an oven at 180°C for curing for 3h, after curing, the oven switch was turned off and the mold was naturally cooled to room temperature to form an epoxy resin cured product.

[0112] The viscosity of the epoxy resin composition obtained in Comparative Example 2 was 69 mPa.s at the working temperature of the liquid molding resin (100°C), and the operation time was 12.1h.

[0113] The tensile strength of the epoxy resin cured product obtained in Comparative Example 2 was 77.4 MPa, the tensile modulus was 3.4 GPa, the fracture toughness was 1.23 MPa.m 1 / 2 , and the glass transition temperature was 194°C.

[0114] Comparative Example 3

[0115] This comparative example provides a method for preparing a toughened epoxy resin, comprising the following steps:

[0116] (1) 20 parts of 4,4'-diamino diphenyl methane tetraglycidyl amine epoxy resin, 40 parts of p-aminophenol triglycidyl epoxy resin and 40 parts of m-aminophenol triglycidyl epoxy resin were mixed at 80°C, then 6 parts of thermoplastic PES polymer particles (weight average molecular weight 55000, particle size 1-1.2 μm) were added, mixed and stirred at 120°C until the thermoplastic polymer particles were completely dissolved to obtain a mixture;

[0117] (2) 96 parts of 4,4'-methylene bis-(3-chloro-2,6-diethyl aniline) curing agent was slowly added to the mixture obtained in step (1) at 80°C, the temperature was raised to 100°C and mixed for 60 min under stirring to obtain a toughened epoxy resin.

[0118] The epoxy resin composition obtained in Comparative Example 3 was placed in a vacuum oven at 80°C to eliminate air bubbles in the resin; the resin composition was cast into a mold, placed in an oven at 180°C for 3h, and after curing, the oven switch was turned off to allow the epoxy resin cured product to cool to room temperature naturally.

[0119] The epoxy resin composition obtained in Comparative Example 3 had a viscosity of 92 mPa.s at the working temperature of the liquid molding resin (100°C) and an operation time of 11.7h.

[0120] The epoxy resin cured product obtained in Comparative Example 3 had a tensile strength of 78.8 MPa, a tensile modulus of 3.6 GPa, a fracture toughness of 0.77 MPa.m 1 / 2 , and a glass transition temperature of 192°C, as tested according to the aforementioned standards.

[0121] The above description is merely preferred embodiments of the present application, and it should be noted that those skilled in the art can make several improvements and refinements without departing from the principles of the present application, and these improvements and refinements should also be considered within the scope of the present application.

Claims

1. A high temperature resistant, multiscale synergistically toughened epoxy resin, characterized in that, Raw materials comprising the following mass fractions: epoxy resin 80~110 parts; curing agent 80~100 parts; toughening particles 5~20 parts; wherein the epoxy resin comprises a mixture of a trifunctional epoxy resin and a tetrafunctional epoxy resin; the toughening particles comprise a mixture of core-shell particles and thermoplastic polymer particles; the core-shell particles have a particle size of 80~200 nm; the inner core of the core-shell particles is an acrylate soft monomer polymer; the acrylate soft monomer used in the acrylate soft monomer polymer comprises one or more of isooctyl acrylate, ethyl acrylate, lauryl acrylate, butyl acrylate, 2-ethylhexyl acrylate, and lauryl methacrylate; the outer shell of the core-shell particles is an acrylate hard monomer polymer; the acrylate hard monomer used in the acrylate hard monomer polymer comprises one or more of methyl acrylate, acrylonitrile, methyl methacrylate, acrylamide, and styrene; the thermoplastic polymer particles have a particle size of 0.5~2 µm; the mass ratio of the core-shell particles to the thermoplastic polymer particles is 1:2~2:

1.

2. A high temperature resistant multi-scale synergistically toughened epoxy resin as claimed in claim 1, wherein, the trifunctional epoxy resin comprises one or both of 4,5-epoxycyclohexane-1,2-dicarboxylic acid diglycidyl ester, m-aminophenol triglycidyl epoxy resin, and p-aminophenol triglycidyl epoxy resin; the tetrafunctional epoxy resin comprises 3,3'-diethyl-4,4'-diaminodiphenylmethane tetraglycidyl amine and / or 4,4'-diaminodiphenylmethane tetraglycidyl amine epoxy resin.

3. A high temperature resistant multi-scale synergistically toughened epoxy resin as claimed in claim 1, wherein, the curing agent comprises 4,4'-methylenebis-(3-chloro-2,6-diethylbenzenamine) and / or 3,3'-dichloro-4,4'-diaminodiphenylmethane.

4. A high temperature resistant multi-scale synergistically toughened epoxy resin as claimed in claim 1, wherein, the thermoplastic polymer particles comprise one or more of polyether sulfone, polyamide, polyetherimide, and polyether ether ketone.

5. The method for preparing a high temperature resistant multi-scale synergistically toughened epoxy resin according to any one of claims 1-4, characterized in that, comprising the following steps: (1) mixing the core-shell particles and the trifunctional epoxy resin using a phase transfer method, the mass ratio of the core-shell particles to the trifunctional epoxy resin being 1:3~4, to obtain a first mixture; (2) mixing the tetrafunctional epoxy resin, the remaining trifunctional epoxy resin, and the thermoplastic polymer particles to obtain a second mixture; (3) mixing the first mixture, the second mixture, and the curing agent to obtain the high-temperature-resistant multi-scale synergistically toughened epoxy resin; wherein steps (1) and (2) are not limited in order.

6. The method according to claim 5, wherein the method is characterized by, in step (3), the mixing conditions of the first mixture, the second mixture, and the curing agent include a mixing temperature of 90~120℃ and a mixing time of 40~60 min.

7. Use of the high-temperature-resistant multi-scale synergistically toughened epoxy resin of any one of claims 1~4 or prepared by the method of any one of claims 5~6 in liquid molding to manufacture a composite material.