Epoxy resin composition, preparation method thereof and composite material

Abstract

The invention provides an epoxy resin composition, a preparation method thereof and a composite material. The epoxy resin composition comprises the following raw material components in parts by mass: 50-100 parts of a resin matrix; 11 to 15 parts by mass of thermoplastic toughening particles; 25-35 parts by mass of an aromatic amine curing agent; 2-8 parts by mass of a reactive diluent; and the molar ratio of the amino group in the aromatic amine curing agent to the epoxy group in the resin matrix is 1.0-1.3. By adjusting the content of each raw material component in the epoxy resin composition, the content of the thermoplastic toughening particles, the resin matrix and the aromatic amine curing agent is in a proper range, and the molar ratio of amino in the curing agent to epoxy group in the resin matrix is controlled. Therefore, the polymer formed by the resin composition has good strength and toughness. Besides, the reactive diluent can reduce the viscosity of the resin matrix, so that the thermoplastic toughening particles can be well dispersed in the resin matrix in the dispersion stage, and the impact resistance of a polymer formed by the resin composition is improved.

Description

Technical Field

[0001] The present disclosure relates to the technical field of composite materials, and in particular to an epoxy resin composition and a preparation method thereof, and a composite material. Background Art

[0002] Composite materials are widely used and favored due to their high mechanical strength, good fatigue resistance and corrosion resistance, and low density. Composite materials are formed by reinforcing fibers and matrix resins, and the mechanical properties of the matrix resin have an important influence on the mechanical properties of composite materials. At present, in order to improve the toughness of the matrix resin, a high proportion of toughening agent is usually added to the composition forming the matrix resin, but the strength and modulus of the matrix resin will be affected and weakened. Therefore, how to take into account both the strength and toughness of the matrix resin is a problem that needs to be solved. Summary of the invention

[0003] In order to overcome the problems existing in the related art, the present disclosure provides an epoxy resin composition and a preparation method thereof, and a composite material.

[0004] According to a first aspect of the present disclosure, an epoxy resin composition is provided, wherein the raw material components in the epoxy resin composition are expressed in parts by mass as follows:

[0005] Resin matrix: 50-100 parts by mass;

[0006] Thermoplastic toughening particles: 11-15 parts by mass;

[0007] Aromatic amine curing agent: 25-35 parts by mass;

[0008] Active diluent: 2-8 parts by mass;

[0009] The molar ratio of the amine groups in the aromatic amine curing agent to the epoxy groups in the resin matrix is ​​1.0-1.3.

[0010] In some embodiments of the present disclosure, the resin matrix includes at least one of bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, bisphenol S diglycidyl ether, tetraglycidyl 4,4-diaminodiphenylmethane, and aminophenol-based trifunctional epoxy resin.

[0011] In some embodiments of the present disclosure, the resin matrix includes: 15-25 parts by mass of bisphenol A diglycidyl ether; 5-15 parts by mass of aminophenol-based trifunctional epoxy resin; and 30-45 parts by mass of tetraglycidyl 4,4-diaminodiphenylmethane.

[0012] In some embodiments of the present disclosure, the aromatic amine curing agent includes 3,3 diaminodiphenyl sulfone and 4,4 diaminodiphenyl sulfone;

[0013] Among them, 3,3-diaminodiphenyl sulfone is 10-14 parts by mass, and 4,4-diaminodiphenyl sulfone is 15-19 parts by mass.

[0014] In some embodiments of the present disclosure, the active diluent includes at least one of butyl glycidyl ether, trimethylolpropane triglycidyl ether, alkylene glycidyl ether, and phenyl glycidyl ether.

[0015] In some embodiments of the present disclosure, the active diluent includes: butyl glycidyl ether: 1-5 parts by mass; trimethylolpropane triglycidyl ether: 1-3 parts by mass.

[0016] In some embodiments of the present disclosure, the particle size of the thermoplastic toughening particles is 50 μm to 500 μm;

[0017] The material of the thermoplastic toughening particles includes at least one of polyethersulfone, polyphenylene ether, polyetheretherketone and polyaryletherketone.

[0018] According to a second aspect of the present disclosure, a method for preparing an epoxy resin composition is provided, the method for preparing the epoxy resin composition comprising:

[0019] Under first preset conditions, stirring the resin matrix to obtain a first solution;

[0020] Under the second preset condition, adding a reactive diluent to the first solution for mixing to obtain a second solution;

[0021] Under a third preset condition, adding thermoplastic toughening particles into the second solution for dispersion treatment in multiple times to obtain a third solution;

[0022] Under a fourth preset condition, the thermoplastic toughening particles in the third solution are dissolved to obtain a fourth solution;

[0023] Under the fifth preset condition, adding an aromatic amine curing agent into the fourth solution and dispersing it to obtain the epoxy resin composition;

[0024] The raw material components in the epoxy resin composition are expressed in parts by mass as follows: resin matrix: 50-100 parts by mass; thermoplastic toughening particles: 11-15 parts by mass; aromatic amine curing agent: 25-35 parts by mass; active diluent: 2-8 parts by mass; wherein the molar ratio of the amine group in the aromatic amine curing agent to the epoxy group in the resin matrix is ​​1.0-1.3.

[0025] In some embodiments of the present disclosure, the first preset condition includes: stirring temperature: 70°C-90°C, stirring time: 20min-40min, stirring speed: 20rpm / min-40rpm / min; and / or,

[0026] The second preset conditions include: mixing temperature: 70°C-90°C, mixing time: 20min-40min, rotation speed: 10rpm / min-30rpm / min; and / or,

[0027] The third preset conditions include: dispersion temperature: 70°C-90°C, dispersion time after each feeding: 10min-20min, rotation speed: 400rpm / min-500rpm / min; and / or,

[0028] The fourth preset conditions include: dissolution temperature: 150°C-160°C, dissolution time: 60min-90min, rotation speed: 400rpm / min-500rpm / min; and / or,

[0029] The fifth preset condition includes: temperature: 50°C-60°C, time: 20min-40min.

[0030] According to a third aspect of the present disclosure, a composite material is provided. The composite material includes reinforcement fibers and a matrix resin wrapping the reinforcement fibers. The matrix resin is formed from the epoxy resin composition provided by the first aspect of the present disclosure.

[0031] The technical solution provided by the embodiments of the present disclosure may include the following beneficial effects: by adjusting the content of each raw material component in the epoxy resin composition, the content of the three main components of thermoplastic toughening particles, resin matrix, and aromatic amine curing agent is within a suitable range, and the molar ratio of the amine group in the curing agent to the epoxy group in the resin matrix is ​​controlled, so that the polymer formed by the resin composition has both good strength and toughness. In addition, the active diluent can reduce the viscosity of the resin matrix, so that the thermoplastic toughening particles can be well dispersed in the resin matrix during the dispersion stage, avoiding the situation where the thermoplastic toughening particles agglomerate in the resin composition and cause uneven mechanical properties, and the active diluent can participate in the reaction when the resin composition is cured to form a uniform system, so as to improve the impact resistance of the polymer formed by the resin composition.

[0032] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present disclosure. DETAILED DESCRIPTION

[0033] Here, exemplary embodiments are described in detail. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Instead, they are only examples of devices and methods consistent with some aspects of the present invention as detailed in the appended claims.

[0034] Composite materials are widely used and favored due to their high mechanical strength, good fatigue resistance and corrosion resistance, and low density. Composite materials are formed by reinforcing fibers and matrix resins, and the mechanical properties of the matrix resin have an important influence on the mechanical properties of composite materials. At present, in order to improve the toughness of the matrix resin, a high proportion of toughening agent is usually added to the composition forming the matrix resin, but the strength and modulus of the matrix resin will be affected and weakened. Therefore, how to take into account both the strength and toughness of the matrix resin is a problem that needs to be solved.

[0035] In order to solve the above technical problems, the present disclosure provides an epoxy resin composition, wherein the raw material components in the epoxy resin composition are expressed in parts by mass as follows: resin matrix: 50-100 parts by mass; thermoplastic toughening particles: 11-15 parts by mass; aromatic amine curing agent: 25-35 parts by mass; reactive diluent: 2-8 parts by mass; the molar ratio of the amine group in the aromatic amine curing agent to the epoxy group in the resin matrix is ​​1.0-1.3. By adjusting the content of each raw material component in the epoxy resin composition, the content of the three main components of the thermoplastic toughening particles, the resin matrix, and the aromatic amine curing agent is within a suitable range, and the molar ratio of the amine group in the curing agent to the epoxy group in the resin matrix is ​​controlled, so that the polymer formed by the resin composition has both good strength and toughness. In addition, the active diluent can reduce the viscosity of the resin matrix, so that the thermoplastic toughening particles can be well dispersed in the resin matrix during the dispersion stage, avoiding the agglomeration of the thermoplastic toughening particles in the resin composition resulting in uneven mechanical properties. The active diluent can participate in the reaction when the resin composition is cured to form a uniform system, thereby improving the impact resistance of the polymer formed by the resin composition.

[0036] An exemplary embodiment of the present disclosure provides an epoxy resin composition, in which the raw material components in the epoxy resin composition are expressed in parts by mass as follows: resin matrix: 50-100 parts by mass; thermoplastic toughening particles: 11-15 parts by mass; aromatic amine curing agent: 25-35 parts by mass; reactive diluent: 2-8 parts by mass; the molar ratio of the amine group in the aromatic amine curing agent to the epoxy group in the resin matrix is ​​1.0-1.3.

[0037] The resin matrix is ​​a resin with an epoxy group. The resin matrix is ​​used as the main agent in the epoxy resin composition. The resin matrix can fully infiltrate the reinforcement fiber. When the resin matrix is ​​cross-linked and cured, the resin matrix forms a mesh structure and is bonded to the reinforcement fiber as a whole, which plays a role in orienting and positioning the reinforcement fiber, and can transfer stress during the product stress process, so that the formed composite material has a certain strength and can withstand tensile stress, bending stress, compression stress, etc. The resin matrix can be a saturated epoxy resin, an unsaturated epoxy resin, a cycloaliphatic epoxy resin, an alicyclic epoxy resin, a heterocyclic epoxy resin, etc. It is understood that the resin matrix can be any suitable difunctional epoxy resin, trifunctional epoxy resin and / or multifunctional epoxy resin. In some examples, the resin matrix includes at least one of bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, bisphenol S diglycidyl ether, tetraglycidyl 4,4 diaminodiphenylmethane, and aminophenol trifunctional epoxy resin.

[0038] Among them, the bisphenol A diglycidyl ether molecules contain hydroxyl groups and ether bonds, and new hydroxyl groups and ether bonds are further generated during the curing process, so that the cured product has higher cohesion and adhesion. The bisphenol A diglycidyl ether in the present disclosure can adopt low viscosity models such as E55, E51, and E44, so that the thermoplastic toughening particles can be well evenly dispersed during the preparation of the epoxy resin composition. For example, the viscosity of E44 type bisphenol A at 25°C is between 20Pa.s and 40Pa.s.

[0039] Bisphenol F diglycidyl ether is prepared by etherification and ring-closing reaction of bisphenol F and excess epichlorohydrin under the catalysis of tetramethylammonium chloride and alkaline conditions. The viscosity of bisphenol F diglycidyl ether is low, and the viscosity at 25°C is between 0.9Pa.s and 1.5Pa.s, which is conducive to the good uniform dispersion of thermoplastic toughening particles.

[0040] Bisphenol S diglycidyl ether is obtained by polycondensation of bisphenol S and excess epichlorohydrin under alkaline conditions. The presence of a highly polar sulfone group in the molecule makes the cured product of bisphenol S diglycidyl ether have good thermal stability and a high heat deformation temperature. Bisphenol S diglycidyl ether is a light yellow solid at room temperature. It can be mixed with other low-viscosity epoxy resins or directly diluted with an active diluent so that the thermoplastic toughening particles can be well evenly dispersed.

[0041] Tetraglycidyl 4,4-diaminodiphenylmethane is prepared by addition polycondensation of 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl ether, and 4,4'-diaminodiphenyl sulfone with epichlorohydrin in the presence of a catalyst and a base. The cured resin has a high crosslinking density and good thermal stability. The viscosity of tetraglycidyl 4,4-diaminodiphenylmethane is relatively high, ranging from 220Pa.s to 620Pa.s at 50°C. Therefore, tetraglycidyl 4,4-diaminodiphenylmethane can be mixed with other low-viscosity epoxy resins, or directly diluted with a reactive diluent, so that the thermoplastic toughened particles can be well evenly dispersed.

[0042] The aminophenol-based trifunctional epoxy resin molecule has multiple epoxy groups and aromatic rings, which can form a higher cross-linking density during the curing process, so that the cured product has good heat resistance and mechanical strength. Its viscosity at 25°C is between 1.5Pa.s and 5.0Pa.s, which is conducive to the good uniform dispersion of thermoplastic toughening particles.

[0043] Thermoplastic toughening particles can improve the toughness of the cured product formed by the resin matrix, reduce the brittleness of the cured product, and effectively prevent the propagation of cracks, thereby improving the impact resistance of the material. Thermoplastic toughening particles can be uniformly dispersed in the resin matrix before adding the aromatic amine cured product, and dissolved in the resin composition by heating. The material of the thermoplastic toughening particles can be a thermoplastic resin, which can include the following materials alone or in combination: polyurethane, polyamide, copolyamide, polyimide, aromatic polyamide, polyketone, polyetheretherketone, polyaryletherketone, polyester, polysulfone, polyethersulfone, polyphenylene oxide, elastomer, liquid crystal polymer, block elastomer, etc. In some examples, the material of the thermoplastic toughening particles includes at least one of polyethersulfone, polyphenylene oxide, polyetheretherketone, and polyaryletherketone.

[0044] It is understandable that the particle size of the thermoplastic toughening particles should be controlled within an appropriate range. If the particle size is too small, it is easy to greatly increase the viscosity of the resin system after adding it to the resin matrix, and it is easy to agglomerate in the resin system; if the particle size is too large, the thermoplastic toughening particles cannot be well dissolved in the resin system, and it is easy to have poor uniformity. In some examples, the particle size of the thermoplastic toughening particles can be between 50μm and 500μm. In some examples, the particle size of the thermoplastic toughening particles can be between 80μm and 300μm. In some examples, the particle size of the thermoplastic toughening particles can be between 100μm and 200μm.

[0045] Since the molecules in the resin matrix are linear structures, the aromatic amine curing agent is used to promote the ring-opening polymerization of the resin matrix, and to perform addition polymerization or catalytic polymerization with the epoxy group of the resin matrix to form a cross-linked cured product with a three-dimensional network structure. The aromatic amine curing agent may include m-phenylenediamine, 1,3-diaminobenzene, 4,4'-diaminodiphenylmethane, 1,4-diaminobenzene, and polyaminosulfones (including 4,4'-diaminodiphenylsulfone, 3,3'-diaminodiphenylsulfone, 4-aminophenylsulfone, etc.). In some examples, the aromatic amine curing agent uses 4,4'-diaminodiphenylsulfone (4,4'-DDS) with low reactivity. In other examples, the aromatic amine curing agent uses both 4,4'-DDS with low reactivity and 3,3'-diaminodiphenylsulfone (3,3'-DDS) with high reactivity. The 3,3'-DDS body can improve the strength of the resin matrix cured product, and the 4,4'-DDS can balance the viscosity of the resin matrix cured product.

[0046] In some examples, in order to achieve an optimal balance between the external life, adhesion and mechanical properties of the composite material formed by the epoxy resin composition, the molar ratio of the amine groups in the aromatic amine curing agent to the epoxy groups in the resin matrix is ​​controlled between 1.0 and 1.3.

[0047] Reactive diluents are a class of low molecular weight epoxy compounds containing epoxy groups, which have light color and low viscosity. They have good compatibility with resin matrices including epoxy resins, can reduce the viscosity of the resin matrix, so that the thermoplastic toughening particles can be well dispersed, and can participate in the curing reaction of the resin matrix, become part of the cross-linked network structure of the cured product, and reduce the shrinkage of the cured product. In some examples, the reactive diluent may include at least one of butyl glycidyl ether, trimethylolpropane triglycidyl ether, alkylene glycidyl ether, and phenyl glycidyl ether. Among them, butyl glycidyl ether contains ether bonds and epoxy groups in the molecule, participates in the reaction when the resin matrix is ​​cured, and has a viscosity of about 0.002 Pa.s at 25°C. Trimethylolpropane triglycidyl ether contains three hydroxyl groups and three epoxy groups in the molecule, participates in the reaction when the resin matrix is ​​cured, and has a viscosity of between 0.1 Pa.s and 0.2 Pa.s at 25°C. The viscosity of alkylene glycidyl ether at 25°C is about 0.002 Pa.s. The viscosity of phenyl glycidyl ether at 25°C is between 0.002 Pa.s and 0.008 Pa.s.

[0048] In some examples, the raw material components in the epoxy resin composition are expressed in parts by mass as follows: resin matrix: 50-100 parts by mass; thermoplastic toughening particles: 11-15 parts by mass; aromatic amine curing agent: 25-35 parts by mass; active diluent: 2-8 parts by mass.

[0049] In some examples, the raw material components in the epoxy resin composition are expressed in parts by mass as follows: resin matrix: 50-100 parts by mass; thermoplastic toughening particles: 11-15 parts by mass; aromatic amine curing agent: 25-35 parts by mass; reactive diluent: 2-8 parts by mass. The resin matrix may include at least two of bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, bisphenol S diglycidyl ether, tetraglycidyl 4,4-diaminodiphenylmethane, and aminophenol trifunctional epoxy resin, and the mass ratio of low viscosity resin to high viscosity resin in the resin matrix is ​​controlled to be 4:6, so that the resin matrix can satisfy the thermoplastic toughening particles for good even distribution and dispersion, and the cured product of the resin matrix has good crosslinking density and strength.

[0050] In some examples, the raw material components in the epoxy resin composition are expressed in parts by mass as follows: resin matrix: 50-100 parts by mass; thermoplastic toughening particles: 11-15 parts by mass; aromatic amine curing agent: 25-35 parts by mass; reactive diluent: 2-8 parts by mass. Among them, the resin matrix includes: bisphenol A diglycidyl ether: 15-25 parts by mass; aminophenol trifunctional epoxy resin: 5-15 parts by mass; tetraglycidyl 4,4-diaminodiphenylmethane: 30-45 parts by mass.

[0051] In some examples, the raw material components in the epoxy resin composition are expressed in parts by mass as follows: resin matrix: 50-100 parts by mass; thermoplastic toughening particles: 11-15 parts by mass; aromatic amine curing agent: 25-35 parts by mass; reactive diluent: 2-8 parts by mass. Among them, the aromatic amine curing agent includes: 3,3 diaminodiphenyl sulfone: 10-14 parts by mass; 4,4 diaminodiphenyl sulfone: 15-19 parts by mass.

[0052] In some examples, the raw material components in the epoxy resin composition are expressed in parts by mass as follows: resin matrix: 50-100 parts by mass; thermoplastic toughening particles: 11-15 parts by mass; aromatic amine curing agent: 25-35 parts by mass; active diluent: 2-8 parts by mass. Among them, the active diluent includes: butyl glycidyl ether: 1-5 parts by mass; trimethylolpropane triglycidyl ether: 1-3 parts by mass.

[0053] In some examples, the raw material components in the epoxy resin composition are expressed in parts by mass as follows: bisphenol A diglycidyl ether: 15-25 parts by mass; aminophenol-based trifunctional epoxy resin: 5-15 parts by mass; tetraglycidyl 4,4-diaminodiphenylmethane: 30-45 parts by mass; thermoplastic toughening particles: 11-15 parts by mass; 3,3-diaminodiphenyl sulfone: 10-14 parts by mass; 4,4-diaminodiphenyl sulfone: 15-19 parts by mass; butyl glycidyl ether: 1-5 parts by mass; trimethylolpropane triglycidyl ether: 1-3 parts by mass.

[0054] It is understandable that on the basis of the epoxy resin composition provided in the present disclosure, other additives may be added in appropriate amounts based on demand, including but not limited to coupling agents, curing accelerators, delayed curing agents, antioxidants, anti-yellowing agents, ultraviolet absorbers, etc.

[0055] In an exemplary embodiment, the present disclosure provides a method for preparing an epoxy resin composition, which is used to prepare the epoxy resin composition provided in the above embodiment of the present disclosure, and the preparation method comprises:

[0056] Step S1, stirring the resin matrix under a first preset condition to obtain a first solution;

[0057] Step S2, under a second preset condition, adding a reactive diluent to the first solution for mixing to obtain a second solution;

[0058] Step S3, under a third preset condition, adding the thermoplastic toughening particles into the second solution for dispersion treatment in multiple times to obtain a third solution;

[0059] Step S4, under a fourth preset condition, the thermoplastic toughening particles in the third solution are dissolved to obtain a fourth solution;

[0060] Step S5: under the fifth preset condition, adding the aromatic amine curing agent into the fourth solution and dispersing it to obtain an epoxy resin composition.

[0061] In step S1, under the first preset condition, the resin matrix is ​​stirred so that the resin matrix is ​​evenly dispersed. When the resin matrix includes a plurality of epoxy resin materials, the stirring process can make the plurality of epoxy resins evenly mixed to obtain a first solution. Since the resin matrix may include epoxy resins that exist as solids at room temperature, when the resin matrix is ​​stirred, it is necessary to carry out the stirring process at a certain heating temperature to increase the dispersion uniformity of the first solution. In some examples, the first preset condition includes: stirring temperature: 70°C-90°C, stirring time: 20min-40min, stirring speed: 20rpm / min-40rpm / min. In some examples, the first preset condition also includes the protection of an inert atmosphere.

[0062] In some examples, in order to improve the dispersion uniformity of the resin matrix, before stirring the resin matrix, the resin matrix can be placed in an oven or other heating device and preheated at 60°C-80°C for 15min-25min, so that the resin matrix is ​​liquid and the subsequent curing process of the resin matrix can be avoided to cause explosion.

[0063] In step S2, under the second preset condition, the active diluent is added to the first solution for mixing. The purpose of this step is to adjust the viscosity of the resin matrix with the active diluent so that the obtained second solution is conducive to the uniform dispersion of the thermoplastic toughening particles. It can be understood that the temperature condition in the second preset condition is less than the temperature at which the resin matrix is ​​cured. In some examples, the second preset condition includes: mixing temperature: 70°C-90°C, mixing time: 20min-40min, rotation speed: 10rpm / min-30rpm / min. That is to say, when the resin matrix is ​​in a liquid state uniformly stirred in step S1, the active diluent is added thereto while maintaining the temperature. As the viscosity of the second solution gradually decreases, the stirring speed is appropriately reduced.

[0064] In step S3, under the third preset condition, the thermoplastic toughening particles are added to the second solution for uniform dispersion. In order to avoid agglomeration of the thermoplastic toughening particles in the second solution due to a large amount of feeding, a certain mass of thermoplastic toughening particles is added to the second solution in multiple times. Since the second solution includes an active diluent and the viscosity of the second solution at 70°C-90°C is close to 0Pa.s, the dispersion resistance of the thermoplastic toughening particles at this temperature is small, which is conducive to achieving a uniform dispersion effect to obtain a third solution. In some examples, the third preset condition includes: dispersion temperature: 70°C-90°C, dispersion time after each feeding: 10min-20min, rotation speed: 400rpm / min-500rpm / min. That is to say, when the second solution is in a liquid state uniformly stirred in step S2, the temperature is maintained and the thermoplastic toughening particles are added thereto in multiple times. In order to ensure the uniformity of dispersion of the thermoplastic toughening particles, stirring and dispersion are continued for 10min-20min after each addition. Since the viscosity of the system gradually increases after the addition of the thermoplastic toughening particles, the stirring speed is appropriately increased to 400rpm / min-500rpm / min.

[0065] It is understandable that after adding the thermoplastic toughening particles, the system cannot be evenly dispersed by the stirring paddle due to its high viscosity. The stirring speed mainly refers to the speed of the dispersion disk to destroy the toughening particles that are clumping or agglomerated.

[0066] It can be understood that during the dispersion of the thermoplastic toughening particles, since the thermoplastic toughening particles are in contact with the resin matrix, the thermoplastic toughening particles can absorb the resin matrix to swell.

[0067] In step S4, the thermoplastic toughening particles gradually change from a solid state to a liquid state to form a fourth solution. The fourth preset condition mainly includes temperature, rotation speed and time. It can be understood that the temperature of the fourth preset condition needs to be lower than the temperature at which the resin matrix undergoes self-polymerization to avoid affecting the degree of curing of the resin matrix. In some examples, the fourth preset condition includes: dissolution temperature: 150°C-160°C, dissolution time: 60min-90min, rotation speed: 400rpm / min-500rpm / min. That is to say, when the third solution is in a uniformly dispersed state in step S3, the rotation speed is not adjusted. After the heating temperature is adjusted to 150°C-160°C, the temperature and rotation speed are maintained to dissolve the thermoplastic toughening particles so that the dissolved toughening agent is evenly dispersed in the resin system to obtain a fourth solution.

[0068] In step S5, an aromatic amine curing agent is added to the fourth solution and dispersed to obtain an epoxy resin composition. In order to avoid the curing agent being added to the fourth solution and causing a polymerization reaction in the resin system, the fourth solution needs to be cooled to a certain temperature before the aromatic amine curing agent is added. Therefore, the fifth preset condition may include: the temperature of the resin system: 50°C-60°C, the dispersion time of the aromatic amine curing agent: 20min-40min, so that the aromatic amine curing agent is evenly dispersed in the resin system, and the resin matrix is ​​still in an unpolymerized state to obtain an epoxy resin composition.

[0069] In the epoxy resin composition, each raw material component is expressed in parts by mass as follows: resin matrix: 50-100 parts by mass; thermoplastic toughening particles: 11-15 parts by mass; aromatic amine curing agent: 25-35 parts by mass; active diluent: 2-8 parts by mass; wherein the molar ratio of the amine group in the aromatic amine curing agent to the epoxy group in the resin matrix is ​​1.0-1.3.

[0070] In some examples, after the epoxy resin composition is formed, in order to improve the mechanical strength of the cured product formed by the epoxy resin composition, the epoxy resin composition may be subjected to a vacuum degassing treatment to remove bubbles in the epoxy resin composition. The treatment temperature during vacuum degassing may be between 60° C. and 70° C., and the degassing time may be 20 min to 30 min.

[0071] In an exemplary embodiment, the present disclosure also provides a composite material, the composite material includes a reinforcement fiber and a matrix resin wrapped around the reinforcement fiber, and the matrix resin is cured by the epoxy resin composition provided in the above embodiment of the present disclosure. The temperature at which the epoxy resin composition is cured to form the matrix resin can be between 175°C and 190°C, and the holding time can be 1.5h-2.5h. The matrix resin is cross-linked and cured to form a three-dimensional mesh structure with good mechanical properties, so that the composite material has the advantages of high strength, good impact resistance and high toughness. In the composite material, the reinforcement fiber can include glass fiber, carbon fiber, aramid fiber, basalt fiber, polyarylate fiber, polyamide fiber, ultra-high molecular weight polyethylene fiber, polyphenylene benzobisoxazole fiber, polyvinyl alcohol fiber, etc. The reinforcement fiber can be continuous fiber filaments, fiber bundles, fiber woven cloths, fiber felts, etc. It can be understood that the reinforcement fiber can be a fiber comprising a material alone, or a mixed fiber formed by mixing two or more fibers.

[0072] In order to more clearly explain the technical solution of the present disclosure, the performance of the epoxy resin composition provided by the present disclosure is described in detail below in conjunction with specific examples. The examples and comparative examples are all polymer casting specimens formed by curing the resin composition system.

[0073] Example 1

[0074] Bisphenol A diglycidyl ether (DGEBA), aminophenol trifunctional epoxy resin (TGAP) and tetraglycidyl 4,4-diaminodiphenylmethane (TGDDM) are placed in an oven and preheated at 65°C for 15 minutes; under the protection of nitrogen, 17 parts by mass of bisphenol A diglycidyl ether, 6 parts by mass of aminophenol trifunctional epoxy resin and 32 parts by mass of tetraglycidyl 4,4-diaminodiphenylmethane are added into a reaction kettle, stirred at a low speed of 20 rpm / min, and premixed at 80°C for 30 minutes to obtain a first solution; 3 parts by mass of butyl glycidyl ether and 2 parts by mass of trimethylolpropane triglycidyl ether are added, stirred at a low speed of 20 rpm / min, and premixed at 70°C-90°C for 30 minutes to obtain a second solution. After the temperature in the reactor is kept stable at 70°C-90°C, 11 parts by mass of thermoplastic toughening particles are added in multiple batches for dispersion. The speed of the dispersion disk is 400rpm / min. After the feeding is completed, the dispersion is dispersed for 15 minutes to obtain the third solution. After the thermoplastic toughening particles are dispersed, the temperature is raised to 160°C, the speed of the dispersion disk is 400rpm / min, and the solution is dissolved for 90 minutes to obtain the fourth solution. The fourth solution is cooled to 50°C, 17 parts by mass of 4,4`-DDS and 12 parts by mass of 3,3`-DDS are added, and the dispersion is mixed for 30 minutes to obtain an epoxy resin composition. The vacuum degassing mode is turned on, and the degassing is carried out at 65°C for 20 minutes. The fifth solution of the epoxy resin composition that has been vacuum degassed is cured for 2 hours under the autoclave curing system at 180°C to obtain a polymer casting body strip.

[0075] Example 2

[0076] The feeding preparation process is similar to that of Example 1, except that the raw material components of the epoxy resin composition are expressed in parts by mass as follows: bisphenol A diglycidyl ether: 25 parts by mass; aminophenol-based trifunctional epoxy resin: 6 parts by mass; tetraglycidyl 4,4-diaminodiphenylmethane: 40 parts by mass; thermoplastic toughening particles: 15 parts by mass; 4,4`-DDS: 19 parts by mass; 3,3`-DDS: 10 parts by mass; butyl glycidyl ether: 5 parts by mass; trimethylolpropane triglycidyl ether: 3 parts by mass.

[0077] Example 3

[0078] The feeding preparation process is similar to that of Example 1, except that the raw material components of the epoxy resin composition are expressed in parts by mass as follows: bisphenol A diglycidyl ether: 15 parts by mass; aminophenol-based trifunctional epoxy resin: 15 parts by mass; tetraglycidyl 4,4-diaminodiphenylmethane: 45 parts by mass; thermoplastic toughening particles: 13 parts by mass; 4,4`-DDS: 15 parts by mass; 3,3`-DDS: 14 parts by mass; butyl glycidyl ether: 5 parts by mass; trimethylolpropane triglycidyl ether: 1 part by mass.

[0079] Example 4

[0080] The feeding preparation process is similar to that of Example 1, except that the raw material components of the epoxy resin composition are expressed in parts by mass as follows: bisphenol A diglycidyl ether: 20 parts by mass; aminophenol-based trifunctional epoxy resin: 10 parts by mass; tetraglycidyl 4,4-diaminodiphenylmethane: 30 parts by mass; thermoplastic toughening particles: 15 parts by mass; 4,4`-DDS: 17 parts by mass; 3,3`-DDS: 12 parts by mass; butyl glycidyl ether: 1 part by mass; trimethylolpropane triglycidyl ether: 3 parts by mass.

[0081] Example 5

[0082] The feeding preparation process is similar to that of Example 1, except that the raw material components of the epoxy resin composition are expressed in parts by mass as follows: bisphenol A diglycidyl ether: 22 parts by mass; aminophenol-based trifunctional epoxy resin: 12 parts by mass; tetraglycidyl 4,4-diaminodiphenylmethane: 38 parts by mass; thermoplastic toughening particles: 14 parts by mass; 4,4`-DDS: 18 parts by mass; 3,3`-DDS: 11 parts by mass; butyl glycidyl ether: 4 parts by mass; trimethylolpropane triglycidyl ether: 2 parts by mass.

[0083] Example 6

[0084] The feeding preparation process is similar to that of Example 1, except that the raw material components of the epoxy resin composition are expressed in parts by mass as follows: bisphenol A diglycidyl ether: 18 parts by mass; aminophenol-based trifunctional epoxy resin: 8 parts by mass; tetraglycidyl 4,4-diaminodiphenylmethane: 35 parts by mass; thermoplastic toughening particles: 11 parts by mass; 4,4`-DDS: 15 parts by mass; 3,3`-DDS: 10 parts by mass; butyl glycidyl ether: 3 parts by mass; trimethylolpropane triglycidyl ether: 1 part by mass.

[0085] Table 1 Glass transition temperature and fracture toughness of examples and comparative examples

[0086]

[0087] Among them, comparative example 1 is a commercially available polymer casting body specimen. Referring to Table 1, it can be seen from the above embodiments and comparative examples that the polymer formed by curing the resin composition provided by the present disclosure has a higher glass transition temperature, indicating that the polymer formed by curing the resin composition has a higher strength, and the fracture toughness is significantly higher than that of the comparative example, indicating that the epoxy resin composition provided by the present disclosure has good strength performance and toughness.

[0088] Those skilled in the art will readily appreciate other embodiments of the present invention after considering the specification and practicing the invention disclosed herein. This application is intended to cover any variations, uses or adaptations of the present invention that follow the general principles of the present invention and include common knowledge or customary techniques in the art that are not disclosed in this disclosure. The specification and examples are to be considered exemplary only, and the true scope and spirit of the present invention are indicated by the following claims.

[0089] It should be understood that the present invention is not limited to the above description and that various modifications and changes may be made without departing from its scope. The scope of the present invention is limited only by the appended claims.

Claims

1. An epoxy resin composition, characterized in that The raw material components in the epoxy resin composition are expressed in parts by mass as follows: Resin matrix: 50-100 parts by mass; Thermoplastic toughening particles: 11-15 parts by mass; Aromatic amine curing agent: 25-35 parts by mass; Active diluent: 2-8 parts by mass; The molar ratio of the amine groups in the aromatic amine curing agent to the epoxy groups in the resin matrix is ​​1.0-1.

3.

2. The epoxy resin composition according to claim 1, characterized in that The resin matrix includes at least one of bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, bisphenol S diglycidyl ether, tetraglycidyl 4,4-diaminodiphenylmethane, and aminophenol-based trifunctional epoxy resin.

3. The epoxy resin composition according to claim 2, characterized in that The resin matrix comprises: 15-25 parts by mass of bisphenol A diglycidyl ether; 5-15 parts by mass of aminophenol-based trifunctional epoxy resin; and 30-45 parts by mass of tetraglycidyl 4,4-diaminodiphenylmethane.

4. The epoxy resin composition according to claim 1, characterized in that The aromatic amine curing agent includes 3,3 diaminodiphenyl sulfone and 4,4 diaminodiphenyl sulfone; Among them, 3,3-diaminodiphenyl sulfone is 10-14 parts by mass, and 4,4-diaminodiphenyl sulfone is 15-19 parts by mass.

5. The epoxy resin composition according to claim 1, characterized in that The active diluent includes at least one of butyl glycidyl ether, trimethylolpropane triglycidyl ether, alkylene glycidyl ether, and phenyl glycidyl ether.

6. The epoxy resin composition according to claim 5, characterized in that The active diluent comprises: 1-5 parts by weight of butyl glycidyl ether; and 1-3 parts by weight of trimethylolpropane triglycidyl ether.

7. The epoxy resin composition according to claim 1, characterized in that The particle size of the thermoplastic toughening particles is 50 μm to 500 μm; The material of the thermoplastic toughening particles includes at least one of polyethersulfone, polyphenylene ether, polyetheretherketone and polyaryletherketone.

8. A method for preparing an epoxy resin composition, characterized in that: The preparation method of the epoxy resin composition comprises: Under first preset conditions, stirring the resin matrix to obtain a first solution; Under the second preset condition, adding a reactive diluent to the first solution for mixing to obtain a second solution; Under a third preset condition, adding thermoplastic toughening particles into the second solution for dispersion treatment in multiple times to obtain a third solution; Under a fourth preset condition, the thermoplastic toughening particles in the third solution are dissolved to obtain a fourth solution; Under the fifth preset condition, adding an aromatic amine curing agent into the fourth solution and dispersing it to obtain the epoxy resin composition; The raw material components in the epoxy resin composition are expressed in parts by mass as follows: resin matrix: 50-100 parts by mass; thermoplastic toughening particles: 11-15 parts by mass; aromatic amine curing agent: 25-35 parts by mass; active diluent: 2-8 parts by mass; wherein the molar ratio of the amine group in the aromatic amine curing agent to the epoxy group in the resin matrix is ​​1.0-1.

3.

9. The method for preparing the epoxy resin composition according to claim 8, characterized in that: The first preset conditions include: stirring temperature: 70°C-90°C, stirring time: 20min-40min, stirring speed: 20rpm / min-40rpm / min; and / or, The second preset conditions include: mixing temperature: 70°C-90°C, mixing time: 20min-40min, rotation speed: 10rpm / min-30rpm / min; and / or, The third preset conditions include: dispersion temperature: 70°C-90°C, dispersion time after each feeding: 10min-20min, rotation speed: 400rpm / min-500rpm / min; and / or, The fourth preset conditions include: dissolution temperature: 150°C-160°C, dissolution time: 60min-90min, rotation speed: 400rpm / min-500rpm / min; and / or, The fifth preset condition includes: temperature: 50°C-60°C, time: 20min-40min.

10. A composite material, characterized in that: The composite material comprises reinforcement fibers and a matrix resin wrapping the reinforcement fibers, wherein the matrix resin is formed from the epoxy resin composition according to any one of claims 1 to 7.

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