High-temperature-resistant multi-scale synergistic toughening epoxy resin as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of epoxy resin modification, and discloses high-temperature-resistant multi-scale synergistically toughened epoxy resin as well as a preparation method and application thereof. The high-temperature-resistant multi-scale synergistic toughening epoxy resin comprises the following raw materials in parts by mass: 80-110 parts of epoxy resin; 80 to 100 parts of a curing agent; and 5-20 parts of toughening particles. According to the invention, by regulating and controlling the molecular structure and the particle morphology of the two toughening particles and the proportion of the toughening particles with various sizes, the advantages of the two toughening particles can be exerted, and the toughening effect can be synergistically exerted, so that an epoxy resin system which is resistant to high temperature, high in toughness and low in viscosity at the pouring temperature and meets the requirements of a liquid forming process is obtained; the method is suitable for manufacturing a civil aviation main load-bearing structure composite material with a complex structure and a large size through a dry fiber automatic laying liquid forming process.

Description

Technical Field

[0001] The present invention relates to the technical field of epoxy resin modification, and in particular to a high temperature resistant multi-scale synergistic toughening epoxy resin and a preparation method and application thereof. Background Art

[0002] High-performance resin-based composite materials have outstanding characteristics such as high specific strength, high specific modulus and excellent molding adaptability, and are widely used in advanced manufacturing fields such as aerospace. Taking the aviation field as an example, the use of high-performance resin-based composite materials has shown rapid growth in both military and civilian aircraft, and its use is even regarded as one of the indicators of the advancement of aircraft. For example, the fuselage parts of Boeing 787 and Airbus A350 passenger aircraft have chosen lightweight composite materials to replace traditional metal materials. Among them, about 50% of the weight of the Boeing 787 passenger aircraft comes from composite materials, which greatly reduces the weight of the whole aircraft.

[0003] In recent years, liquid molding technology has gradually become the focus of research and development in the field of aviation composite material manufacturing due to its advantages such as low design and manufacturing cost, precise control of part size, large degree of freedom in operation, and suitability for integrated manufacturing of complex structures. However, when the resin used in liquid molding is a highly cross-linked thermosetting epoxy resin, its brittle nature makes it difficult for epoxy-based composite materials to meet the damage tolerance requirements of civil aviation main load-bearing composite components. On the other hand, the size of civil aviation main load-bearing structural composite materials is too large, and the use of liquid molding technology requires a longer process window and lower resin viscosity. Generally, the viscosity does not exceed 300mPa.s at the infusion temperature and needs to be maintained for more than 5h. Therefore, in the liquid molding epoxy resin system, due to the dual restrictions of the infusion process on the viscosity of the resin and the fiber filtration effect, conventional prepreg resin toughening methods are almost not applicable, which directly leads to the lack of such high-performance liquid molding epoxy resins.

[0004] So far, the development and modification of epoxy resin for liquid molding has been one of the research focuses at home and abroad. The use of thermoplastic polymer particles and core-shell particles have been proven to effectively improve the toughness of 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 requirements of the liquid molding process; and the addition of core-shell particles alone will reduce the strength and modulus of the matrix resin. It is difficult to simultaneously meet the requirements of the liquid molding process and mechanical properties by simply using thermoplastic polymer particles and core-shell particles. Summary of the invention

[0005] The purpose of the present invention is to provide a high temperature resistant multi-scale synergistic toughening epoxy resin and a preparation method and application thereof, so as to solve the problem that the existing epoxy resin is difficult to simultaneously meet the requirements of liquid molding process and mechanical properties.

[0006] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0007] The present invention provides a high temperature resistant multi-scale synergistic toughening epoxy resin, comprising the following raw materials in parts by mass:

[0008] 80-110 parts of epoxy resin;

[0009] 80-100 parts of curing agent;

[0010] 5-20 parts of toughening particles;

[0011] Wherein, the epoxy resin comprises a mixture of a trifunctional epoxy resin and a tetrafunctional epoxy resin;

[0012] The toughened particles include a mixture of core-shell particles and thermoplastic polymer particles.

[0013] Preferably, in the high temperature resistant multi-scale synergistic toughening epoxy resin, the trifunctional epoxy resin includes 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 includes 3,3'-diethyl-4,4'-diaminodiphenylmethane tetraglycidylamine and / or 4,4'-diaminodiphenylmethane tetraglycidylamine epoxy resin.

[0015] Preferably, in the high temperature resistant multi-scale synergistic toughening epoxy resin, the curing agent includes 4,4'-methylenebis-(3-chloro-2,6-diethylaniline) and / or 3,3'-dichloro-4,4'-diaminodiphenylmethane.

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

[0017] Preferably, in the high temperature resistant multi-scale synergistic toughening epoxy resin, the core of the core-shell particle is an acrylic soft monomer polymer;

[0018] The acrylic soft monomer used in the acrylic soft monomer polymer includes 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 particle is an acrylic acid ester hard monomer polymer;

[0020] The acrylic ester hard monomer used in the acrylic ester 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 synergistic toughening epoxy resin, the particle size of the thermoplastic polymer particles is 0.5 to 2 μm;

[0022] The thermoplastic polymer particles include one or more of polyethersulfone, polyamide, polyetherimide, and polyetheretherketone.

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

[0024] The present invention also provides a method for preparing a high temperature resistant multi-scale synergistic toughening epoxy resin, comprising the following steps:

[0025] (1) mixing the core-shell particles with a trifunctional epoxy resin by a phase transfer method, wherein the mass ratio of the core-shell particles to the trifunctional epoxy resin is 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 a high temperature resistant multi-scale synergistic toughened epoxy resin;

[0028] There is no restriction on the order of steps (1) and (2).

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

[0030] The present invention also provides an application of a high temperature resistant multi-scale synergistic toughening epoxy resin in liquid molding to manufacture composite materials.

[0031] It can be seen from the above technical solution that compared with the prior art, the present invention has the following beneficial effects:

[0032] The high temperature resistant multi-scale synergistic toughening epoxy resin provided by the present invention includes thermoplastic polymer particles and core-shell particles in the toughening particles. By regulating the molecular structure and particle morphology of the two toughening particles and the ratio of the toughening particles of each scale, the advantages of the two toughening particles can be brought into play. Micron-sized thermoplastic polymer particles and nano-sized core-shell particles are dispersed in the matrix epoxy resin in the form of molecules and particles, respectively. Both toughening particles will not be filtered by the fiber and can penetrate around the fiber with the matrix resin. As the curing reaction proceeds, the thermoplastic polymer particles and core-shell particles are evenly distributed in the composite material in the form of particles of different scales, and the multi-scale synergistic toughening technology is utilized to synergistically exert the toughening effect.

[0033] In addition, the two added toughening particles will not react chemically with the matrix epoxy resin, will not affect the chemical reaction characteristics of the matrix resin, and will not shorten the operation time and storage period of the resin. The nano-scale core-shell particles are always dispersed in the epoxy resin in the form of particles throughout the liquid molding process, and their effect on the increase in viscosity is very small. The micron-sized thermoplastic polymer particles are dissolved in the epoxy resin in molecular form. Although the micron-sized thermoplastic polymer particles contribute slightly more to the increase in the viscosity of the matrix resin, the specific ratio of the two toughening ions is controlled, so that the influence of the thermoplastic polymer particles on the overall resin viscosity is reduced, and the low viscosity and long process window can still be maintained at the infusion temperature.

[0034] In summary, the present invention obtains an epoxy resin system that is resistant to high temperatures, has high toughness, has low viscosity at the infusion temperature, and meets the requirements of the liquid molding process. The epoxy resin system is suitable for manufacturing complex and large-sized civil aviation main load-bearing structure composite materials by dry fiber automatic placement liquid molding process. DETAILED DESCRIPTION

[0035] The present invention provides a high temperature resistant multi-scale synergistic toughening epoxy resin, comprising the following raw materials in parts by mass:

[0036] 80-110 parts of epoxy resin;

[0037] 80-100 parts of curing agent;

[0038] 5-20 parts of toughening particles;

[0039] Wherein, the epoxy resin comprises a mixture of a trifunctional epoxy resin and a tetrafunctional epoxy resin;

[0040] The toughened particles include a mixture of core-shell particles and thermoplastic polymer particles.

[0041] In the present invention, 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), and p-aminophenol triglycidyl epoxy resin (CAS: 5026-74-4), and 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 invention, the tetrafunctional epoxy resin preferably includes 3,3'-diethyl-4,4'-diaminodiphenylmethane tetraglycidylamine (CAS: 130728-76-6) and / or 4,4'-diaminodiphenylmethane tetraglycidylamine epoxy resin (CAS: 28768-32-3), and further preferably includes 4,4'-diaminodiphenylmethane tetraglycidylamine epoxy resin.

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

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

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

[0046] In the present invention, 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 invention, when the curing agent is preferably two types, the ratio between the different types of curing agents is not limited and any ratio can be used.

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

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

[0050] In the present invention, the core of the core-shell particles is preferably an acrylic soft monomer polymer.

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

[0052] In the present invention, the shell of the core-shell particles is preferably an acrylic acid ester hard monomer polymer.

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

[0054] In the present invention, when the acrylic soft monomer or the acrylic hard monomer is preferably a plurality of types, the ratio between the types is not limited and any ratio can be used.

[0055] In the present invention, the preparation method of the core-shell particles is preferably emulsion polymerization, suspension polymerization or solution polymerization, and more preferably emulsion polymerization.

[0056] In the present invention, the emulsion polymerization method is not limited. For details, please refer to the Chinese patent application with publication number CN118271792A and patent name "Toughening and Reinforced Nano Core-Shell Particle Toughening Agent and Preparation Method and Application thereof".

[0057] In the present invention, the particle size of the thermoplastic polymer particles is preferably 0.5 to 2 μm, more preferably 0.8 to 1.5 μm, and even more preferably 1 to 1.2 μm.

[0058] In the present invention, the thermoplastic polymer particles preferably include one or more of polyethersulfone, polyamide, polyetherimide, and polyetheretherketone, and further include polyethersulfone, polyamide, polyetherimide, or polyetheretherketone, and more preferably polyethersulfone.

[0059] In the present invention, the weight average molecular weight of the polyethersulfone, the polyamide, the polyetherimide, and the polyetheretherketone is not limited, and products well known to those skilled in the art may be used.

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

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

[0062] In the present invention, the weight fraction of the toughening particles is preferably 6 to 18 parts, more preferably 8 to 16 parts, and even more preferably 14 to 16 parts.

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

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

[0065] (2) mixing the tetrafunctional epoxy resin, the remaining trifunctional epoxy resin and the 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 toughened epoxy resin;

[0067] There is no restriction on the order of steps (1) and (2).

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

[0069] In the present invention, the phase transfer method in step (1) is not limited. For details, please refer to the Chinese patent application with publication number CN118271792A and patent name "Toughening and Reinforced Nano Core-Shell Particle Toughening Agent and Preparation Method and Application thereof".

[0070] In the present invention, in step (2), the method of mixing 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 thermoplastic polymer particles are added thereto for second mixing.

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

[0073] In the present invention, the temperature of the second mixing is preferably 90 to 130°C, more preferably 115 to 125°C, and even more preferably 120°C.

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

[0075] In the present invention, in step (3), the method of mixing the first mixture, the second mixture and the curing agent is preferably: performing a third mixing of the first mixture and the second mixture, and adding the curing agent thereto for a fourth mixing.

[0076] In the present invention, the temperature of the third mixing is preferably 80 to 90° C., more preferably 80 to 85° C., and more preferably 80° C. The time of the third mixing is not limited, as long as the mixing is uniform.

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

[0078] The present invention also provides an application of a high temperature resistant multi-scale synergistic toughening epoxy resin in liquid molding to manufacture composite materials.

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

[0080] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0081] Example 1

[0082] This embodiment provides a method for preparing a high temperature resistant multi-scale synergistic toughening epoxy resin, comprising the following steps:

[0083] (1) Add 200 parts of water and 3.75 parts of sodium dodecylbenzene sulfonate to a reaction kettle, heat to 70°C, start stirring, and after 30 minutes, drop 4 parts of a mixture of isooctyl acrylate and 0.2 parts of ethylene glycol dimethacrylate into the reaction kettle, and add 5 parts of a 5 wt% concentration of ammonium persulfate-sodium methylsulfoxylate initiator system to initiate the generation of a certain amount of seed emulsion; after 1 hour, drop 76 parts of isooctyl acrylate and 3.8 parts of a core layer monomer mixture of ethylene glycol dimethacrylate, and 80 parts of methyl methacrylate and 4 parts of a shell layer monomer mixture of ethylene glycol dimethacrylate at a uniform speed for 3 hours, and the shell layer monomer mixture is added after the core layer monomer mixture; at the same time, drop 3.5 hours at a uniform speed. 10 parts of 5 wt% initiator system; after the initiator system is added, keep warm at 70°C for 1.5 hours, cool naturally, filter through a 200-mesh sieve and put into a storage tank for subsequent use. The particle size of the obtained core-shell particles is 100-120 nm;

[0084] (2) Add 80 g of butanone to a 300 mL beaker, then add 50 g of the core-shell particle emulsion prepared above and stir to mix evenly, then add 25 g of water to the mixture and stir; stop stirring after 30 min, let stand at room temperature for 1 h to form obvious stratification, filter the lower water layer; continue to add 40 g of m-aminophenol triglycidyl epoxy resin to the organic solvent containing the nanoparticles, and remove the solvent by reduced pressure distillation to obtain a core-shell particle-m-aminophenol triglycidyl epoxy resin dispersion, in which the mass ratio of epoxy resin to core-shell particles is 3:1, and the dispersion is named the first mixture;

[0085] (3) 20 parts of 4,4'-diaminodiphenylmethane tetraglycidylamine epoxy resin, 40 parts of p-aminophenol triglycidyl epoxy resin and 10 parts of m-aminophenol triglycidyl epoxy resin were mixed at 80° C., and then 6 parts of thermoplastic polyethersulfone PES polymer particles (weight average molecular weight 55,000, particle size 1-1.2 μm) were added, and the mixture was mixed and 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., 96 parts of 4,4′-methylenebis-(3-chloro-2,6-diethylaniline) curing agent were slowly added, and the mixture was stirred at 100° C. for 60 minutes to obtain a high temperature resistant multi-scale synergistic toughened epoxy resin.

[0087] The epoxy resin composition obtained in Example 1 was placed in a vacuum oven at 80°C to evacuate 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 curing, the oven switch was turned off and allowed to cool naturally 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 liquid molding resin working temperature (100° C.) and an operating time of 9.5 h.

[0089] According to the ASTM D638 standard, the tensile strength of the epoxy resin cured product obtained in Example 1 is 93.8 MPa, and the tensile modulus is 3.3 GPa. According to the ASTM D5045 standard, the fracture toughness of the epoxy resin cured product obtained in Example 1 is 1.29 MPa·m 1 / 2 The glass transition temperature obtained by DMA test is 196℃.

[0090] Example 2

[0091] This embodiment provides a method for preparing a high temperature resistant multi-scale synergistic toughening epoxy resin, comprising the following steps:

[0092] (1) Using isooctyl acrylate as the core and methyl methacrylate as the shell, core-shell particles were prepared by emulsion polymerization. The preparation method was the same as that of step (1) of Example 1. The particle size of the core-shell particles was 100 to 120 nm.

[0093] (2) using a phase transfer technique to transfer the core-shell particles in the aqueous phase to the m-aminophenol triglycidyl epoxy resin, wherein the mass ratio of the epoxy resin to the core-shell particles is 3:1, and the method is the same as that of step (2) of Example 1, to obtain a first mixture;

[0094] (3) 20 parts of 4,4'-diaminodiphenylmethane tetraglycidylamine epoxy resin, 40 parts of p-aminophenol triglycidyl epoxy resin and 10 parts of m-aminophenol triglycidyl epoxy resin were mixed at 80° C., and then 10 parts of thermoplastic PES polymer particles (weight average molecular weight 55,000, particle size 1-1.2 μm) were added, and the mixture was mixed and stirred at 120° C. until the thermoplastic polymer particles were completely dissolved to obtain a second mixture;

[0095] (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′-methylenebis-(3-chloro-2,6-diethylaniline) curing agent were slowly added, and the mixture was stirred at 100° C. for 60 minutes to obtain a high temperature resistant multi-scale synergistic toughened epoxy resin.

[0096] The epoxy resin composition obtained in Example 2 was placed in a vacuum oven at 80°C to evacuate 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 curing, the oven switch was turned off and allowed to cool naturally 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 liquid molding resin working temperature (100° C.) and an operating time of 8.4 h.

[0098] According to the above standards, the tensile strength of the epoxy resin cured product obtained in Example 2 is 92.9 MPa, the tensile modulus is 3.4 GPa, and the fracture toughness is 1.41 MPa·m 1 / 2 , the glass transition temperature is 196℃.

[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 tetraglycidylamine epoxy resin, 40 parts of p-aminophenol triglycidyl epoxy resin and 40 parts of m-aminophenol triglycidyl epoxy resin were mixed at 80°C, 96 parts of 4,4'-methylenebis-(3-chloro-2,6-diethylaniline) curing agent were slowly added thereto, the temperature was raised to 100°C and stirred for 60 minutes to obtain epoxy resin.

[0102] The epoxy resin composition obtained in Comparative Example 1 was placed in a vacuum oven at 80°C to evacuate 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 curing, the oven switch was turned off and allowed 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 liquid molding resin working temperature (100° C.) and an operating time of 13.7 h.

[0104] According to the above standards, the tensile strength of the epoxy resin cured product obtained in Comparative Example 1 is 77.7 MPa, the tensile modulus is 3.7 GPa, and the fracture toughness is 0.70 MPa·m 1 / 2 , the glass transition temperature is 194℃.

[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 were prepared using isooctyl acrylate as the core and methyl methacrylate as the shell. The preparation method was emulsion polymerization. The preparation method was the same as that of step (1) of Example 1. The particle size of the core-shell particles was 100 to 120 nm.

[0108] (2) using a phase transfer technique to transfer the core-shell particles in the aqueous phase to the m-aminophenol triglycidyl epoxy resin, wherein the mass ratio of the epoxy resin to the core-shell particles is 3:1, and the method is the same as that of step (2) of Example 1, to obtain a first mixture;

[0109] (3) mixing 20 parts of 4,4'-diaminodiphenylmethane tetraglycidylamine epoxy resin, 40 parts of p-aminophenol triglycidyl epoxy resin and 10 parts of m-aminophenol triglycidyl epoxy resin 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′-methylenebis-(3-chloro-2,6-diethylaniline) curing agent were slowly added, the temperature was raised to 100° C., and the mixture was stirred and mixed for 60 minutes to obtain a toughened epoxy resin.

[0111] The epoxy resin composition obtained in Comparative Example 2 was placed in a vacuum oven at 80°C to evacuate 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 curing, the oven switch was turned off and allowed to cool naturally to room temperature to form an epoxy resin cured product.

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

[0113] According to the above standards, the tensile strength of the epoxy resin cured product obtained in Comparative Example 2 is 77.4 MPa, the tensile modulus is 3.4 GPa, and the fracture toughness is 1.23 MPa·m 1 / 2 , the glass transition temperature is 194℃.

[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'-diaminodiphenylmethane tetraglycidylamine epoxy resin, 40 parts of p-aminophenol triglycidyl epoxy resin and 40 parts of m-aminophenol triglycidyl epoxy resin were mixed at 80° C., and then 6 parts of thermoplastic PES polymer particles (weight average molecular weight 55,000, particle size 1-1.2 μm) were added, and the mixture was mixed and stirred at 120° C. until the thermoplastic polymer particles were completely dissolved to obtain a mixture;

[0117] (2) Slowly add 96 parts of 4,4'-methylenebis-(3-chloro-2,6-diethylaniline) curing agent to the mixture obtained in step (1) at 80°C, raise the temperature to 100°C and stir and mix for 60 minutes 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 evacuate 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 curing, the oven switch was turned off and allowed to cool naturally to room temperature to form an epoxy resin cured product.

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

[0120] According to the above standards, the tensile strength of the epoxy resin cured product obtained in Comparative Example 3 is 78.8 MPa, the tensile modulus is 3.6 GPa, and the fracture toughness is 0.77 MPa·m 1 / 2 , the glass transition temperature is 192℃.

[0121] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A high temperature resistant multi-scale synergistic toughening epoxy resin, characterized in that: Contains the following raw materials in parts by weight: 80-110 parts of epoxy resin; 80-100 parts of curing agent; 5-20 parts of toughening particles; Wherein, the epoxy resin comprises a mixture of a trifunctional epoxy resin and a tetrafunctional epoxy resin; The toughened particles include a mixture of core-shell particles and thermoplastic polymer particles.

2. A high temperature resistant multi-scale synergistic toughening epoxy resin as claimed in claim 1, characterized in that: The trifunctional epoxy resin includes one or two 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 includes 3,3′-diethyl-4,4′-diaminodiphenylmethane tetraglycidylamine and / or 4,4′-diaminodiphenylmethane tetraglycidylamine epoxy resin.

3. A high temperature resistant multi-scale synergistic toughening epoxy resin as claimed in claim 1, characterized in that: The curing agent includes 4,4'-methylenebis-(3-chloro-2,6-diethylaniline) and / or 3,3'-dichloro-4,4'-diaminodiphenylmethane.

4. The high temperature resistant multi-scale synergistic toughening epoxy resin according to claim 1, characterized in that: The particle size of the core-shell particles is 80-200 nm.

5. A high temperature resistant multi-scale synergistic toughening epoxy resin as claimed in claim 1 or 4, characterized in that: The core of the core-shell particle is an acrylic soft monomer polymer; The acrylic soft monomer used in the acrylic soft monomer polymer includes one or more of isooctyl acrylate, ethyl acrylate, lauryl acrylate, butyl acrylate, 2-ethylhexyl acrylate, and lauryl methacrylate; The shell of the core-shell particle is an acrylic acid ester hard monomer polymer; The acrylic ester hard monomer used in the acrylic ester hard monomer polymer includes one or more of methyl acrylate, acrylonitrile, methyl methacrylate, acrylamide and styrene.

6. The high temperature resistant multi-scale synergistic toughening epoxy resin according to claim 1, characterized in that: The particle size of the thermoplastic polymer particles is 0.5 to 2 μm; The thermoplastic polymer particles include one or more of polyethersulfone, polyamide, polyetherimide, and polyetheretherketone.

7. The high temperature resistant multi-scale synergistic toughening epoxy resin according to claim 1, characterized in that: The mass ratio of the core-shell particles to the thermoplastic polymer particles is 1:2 to 2:

1.

8. The method for preparing a high temperature resistant multi-scale synergistic toughened epoxy resin according to any one of claims 1 to 7, characterized in that: The following steps are involved: (1) mixing the core-shell particles with a trifunctional epoxy resin by a phase transfer method, wherein the mass ratio of the core-shell particles to the trifunctional epoxy resin is 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 a curing agent to obtain a high temperature resistant multi-scale synergistic toughened epoxy resin; There is no restriction on the order of steps (1) and (2).

9. The method for preparing a high temperature resistant multi-scale synergistic toughened epoxy resin according to claim 8, characterized in that: In step (3), the conditions for mixing the first mixture, the second mixture and the curing agent include: a mixing temperature of 90 to 120° C. and a mixing time of 40 to 60 min.

10. Use of a high-temperature resistant multi-scale synergistically toughened epoxy resin as described in any one of claims 1 to 7 or a high-temperature resistant multi-scale synergistically toughened epoxy resin prepared by the preparation method of a high-temperature resistant multi-scale synergistically toughened epoxy resin as described in any one of claims 8 to 9 in liquid molding to manufacture composite materials.