High-performance epoxy resin and preparation method thereof
By physically blending the epoxy resin prepolymer with polymer additives of specific structures, the brittleness problem of epoxy resin materials in dynamic loads and extreme environments is solved, and high toughness and high strength are achieved, and production costs are reduced.
Patent Information
- Application Number
- CN202510363142.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-26
- Publication Date
- 2025-05-27
AI Technical Summary
The existing epoxy resin materials have poor long-term reliability under dynamic loads or extreme environments, mainly due to their highly crosslinked mesh structure, resulting in significant brittleness and insufficient toughness and impact resistance.
By physically blending the epoxy resin prepolymer with a polymer additive of a specific structure, the polymer additive consists of rigid aromatic structural monomers, twisted aromatic structural monomers and functional structural monomers, prepared by Fukroyl alkylation reaction to form a composite material with excellent strength and toughness.
The high toughness and high strength of epoxy resin materials are achieved, which improves the long-term reliability of the material in dynamic loads and extreme environments, and the process is relatively simple and the cost is low.
Smart Images
Figure CN120040918A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of polymer materials, and in particular relates to a high-performance epoxy resin and a preparation method thereof. Background Art
[0002] Epoxy resin is a type of thermosetting polymer material with epoxy groups as its characteristic groups. Its advantages come from its unique molecular structure and cross-linking mechanism. Due to its excellent mechanical properties, chemical resistance, bonding strength and thermal stability, it is widely used in aerospace, electronic packaging, composite materials and coatings. However, its highly cross-linked network structure leads to significant intrinsic brittleness, which is manifested as low fracture toughness, poor impact resistance and high microcrack sensitivity, which seriously restricts its long-term reliability under dynamic loads or extreme environments.
[0003] With the growing demand for lightweight and highly durable materials in the industry, toughening modification of epoxy resins has become an important research direction in the field of materials science. Existing toughening technologies mainly include the following directions: elastomer / rubber blending (such as carboxyl-terminated liquid nitrile rubber, amino-terminated liquid nitrile rubber): absorbing energy by inducing silver streaks or shear yielding through the dispersed phase, but often resulting in a significant decrease in modulus and heat resistance; thermoplastic modification (such as polyetherimide, polyethersulfone): forming a dual-continuous phase structure to improve toughness, but limited by poor compatibility and narrow processing window; nanoparticle filling (such as silica, carbon nanotubes): using the nano effect to enhance interfacial interactions, but prone to agglomeration and a threshold bottleneck in toughening efficiency; topological structure design (such as hyperbranched polymers, core-shell particles): improving toughness through molecular chain entanglement or energy dissipation mechanism, but the synthesis process is complex and costly. The above methods generally face the problem of the inverted relationship between "toughness and strength", and it is difficult to take into account the requirements of industrial production for process compatibility and cost.
[0004] In summary, there is an urgent need to find a low-cost method for preparing high-performance epoxy resin. Summary of the invention
[0005] The purpose of the present invention is to provide a method for preparing a high-performance epoxy resin in view of the above-mentioned deficiencies of the existing toughening technology, so as to solve the problem that toughening and strengthening cannot be taken into account at the same time.
[0006] In order to solve the above technical problems, the technical solution of the present invention is as follows:
[0007] A high-performance epoxy resin, wherein the high-performance epoxy resin is prepared by physically blending an epoxy resin prepolymer and a polymer additive, wherein the polymer additive is composed of a rigid aromatic structure monomer Ar 1 , twisted aromatic structure monomer Ar 2 and functional structural monomer R 2, the structural formula of the polymer additive is as follows:
[0008]
[0009] Among them, x is the molar proportion of the rigid aromatic structural unit in the polymer chain, %; y is the molar proportion of the twisted aromatic structural unit in the polymer chain, %; x is 10% - 50%, and y is 50% - 90%;
[0010] Preferably, the structure of Ar 1 is at least one of the following:
[0011]
[0012] Preferably, the structure of Ar 2 is at least one of the following:
[0013]
[0014] Among them, R 2 in the Ar 1 structure is hydrogen or an alkyl group with 1 - 10 carbon atoms. Preferably, the structure of R 2 is at least one of the following:
[0015]
[0016] A preparation method of a high - performance epoxy resin includes the following steps:
[0017] Step 1: Synthesis of the polymer additive;
[0018] Step 1.1, at room temperature, add the monomer to solvent A, stir to dissolve, then add the functional monomer R 2 , continue to stir evenly, and react for 4 - 8 h to obtain a mixed solution; the monomer includes the rigid aromatic structure monomer Ar 1 and the twisted aromatic structure monomer Ar 2 ;
[0019] Step 1.2, in an ice - bath environment, slowly add strong acid A to the mixed solution using a constant - pressure dropping funnel to prevent excessive heat release. After the addition is completed, add acid B to reduce the acidity, then continue to raise the temperature to room temperature, and stir and react for 4 - 8 h to obtain a blue - uniform mucus.
[0020] Step 1.3, after the reaction is completed, solvent A is added to reduce the viscosity. The reaction mixture is precipitated with an excessive amount of solvent B to obtain a light yellow or white fibrous product, which is washed until the pH is neutral and then dried. The dried product is dissolved in solvent C to prepare a solution, and the solution is poured into solvent B for precipitation to obtain a white fibrous product, which is then boiled 2 - 4 times using an electric heating mantle, filtered, and finally dried in a vacuum oven at 80°C to obtain the polymer additive.
[0021] Further, the Ar 1 、Ar 2 and R 2 The molar ratio of the three monomers is 1:(0.8 - 1):(2 - 3), preferably 1:1:2.5; the total molar concentration of the three monomers in solvent A is 2 - 6 mol / L, preferably 4 mol / L.
[0022] Further, the volume ratio of the strong acid A to the acid B is 1:(0.033 - 0.05).
[0023] Further, the stirring speed is 100 - 200 rpm, and the mechanical stirring speed is preferably 150 rpm. The reaction time is preferably 6 h.
[0024] Further, the low - temperature range of the ice - bath environment is 0 - 5°C, preferably 0°C, which can be achieved by adding ice to the water bath to provide the ice - bath environment.
[0025] Further, the solvent A is one of dichloromethane, chloroform, toluene, and tetrahydrofuran, preferably dichloromethane; the solvent B is one of deionized water, methanol, ethanol, ethyl acetate, saturated sodium carbonate solution, and saturated sodium bicarbonate solution, preferably deionized water; the solvent C is one of N - methylpyrrolidone, N,N - dimethylformamide, N,N - dimethylacetamide, tetrahydrofuran, and dichloromethane, preferably N - methylpyrrolidone; the super - strong acid A is one of trifluoromethanesulfonic acid, fluorosulfonic acid, carborane acid, and perfluorobutanesulfonic acid, preferably trifluoromethanesulfonic acid; the acid B is one of trifluoroacetic acid, trichloroacetic acid, and methanesulfonic acid, preferably trifluoroacetic acid.
[0026] Step 2: Preparation of the epoxy resin composite;
[0027] Step 2.1, dissolve the polymer additive synthesized in Step 1 in solvent D and stir until a homogeneous solution is obtained.
[0028] Step 2.2, pour the viscous epoxy resin into a separate beaker and heat - stir at 60 - 80°C to reduce its viscosity to obtain a liquid epoxy resin.
[0029] Step 2.3: Mix the two solutions obtained in Step 2.1 and Step 2.2, and evaporate the solvent in a rotary evaporation device until Solvent D is completely evaporated. After the solvent is completely evaporated, add a curing agent and stir at 70 °C for 10 min until the curing agent is dissolved and mixed evenly.
[0030] Step 2.4: Place the mixture obtained in Step 2.3 in a vacuum oven to remove residual bubbles. Pour the mixture into a preheated mold, keep it warm at 60 - 70 °C for 0.5 - 1.5 h, at 110 - 130 °C for 1 - 3 h, and at 170 - 190 °C for 1 - 3 h.
[0031] Step 2.5: Slowly cool the mold to room temperature and take out the epoxy resin composite material.
[0032] Further, the Solvent D is one of dichloromethane, chloroform, and tetrahydrofuran, preferably chloroform;
[0033] Further, the epoxy resin is one or a mixture of epoxy resin E-51, epoxy resin E-44, and epoxy resin E-42, preferably epoxy resin E-51;
[0034] Further, the curing agent is one of m-phenylenediamine, 4,4'-diaminodiphenyl sulfone, phthalic anhydride, and pyromellitic dianhydride, preferably m-phenylenediamine;
[0035] Further, the mass ratio of the epoxy resin to the polymer additive is 100:(0 - 12), preferably 100:6;
[0036] Further, the mass ratio of the epoxy resin to the curing agent is 100:(10 - 15), preferably 100:13.
[0037] Effects and benefits of the present invention:
[0038] The present invention prepares a high-performance epoxy resin composite material, which combines high toughness and high strength. It is prepared by physical blending of an epoxy resin prepolymer and a polymer additive. The polymer additive is formed by a Friedel-Crafts acylation reaction catalyzed by a superacid and has a rigid structure, a twisted structure, and a functional structure. The rigid structure endows the polymer additive with excellent strength and provides a certain strength for the epoxy network; the twisted structure endows the polymer with a larger free volume and can effectively toughen the epoxy resin; the functional structure not only endows the epoxy resin with specific functions, but also promotes the compatibility of the polymer additive with the epoxy resin at the molecular level, enhances the interfacial interaction between the polymer additive and the epoxy resin, and to a certain extent also ensures the strength and toughness of the composite material. Description of the drawings
[0039] Figure 1It is the preparation flow chart of epoxy resin composite material.
[0040] Figure 2(a) is the 1H NMR spectrum of the polymer synthesized in Example 1.
[0041] Figure 2(b) is the partial enlarged view of region A in Figure 2(a).
[0042] Figure 3 It is the scanning electron microscope image of the bending fracture surface of the epoxy resin composite material sample in Example 2.
[0043] Figure 4 It is the tensile strength and Young's modulus diagram of the epoxy resin composite material.
[0044] Figure 5 It is the fracture toughness and critical strain energy release rate diagram of the epoxy resin composite material. Specific embodiments
[0045] The technical solutions of the present invention will be further described and illustrated below through specific embodiments in conjunction with the accompanying drawings.
[0046] Control example
[0047] Pour 40 g of epoxy resin E-51 into a separate beaker and stir at 60 °C to reduce its viscosity. Then mix the two solutions and evaporate the solvent in a rotary evaporation device until the solvent is completely evaporated. After the solvent is completely evaporated, add 5.1 g of curing agent m-phenylenediamine and stir at 70 °C for 10 min until the curing agent is dissolved and mixed evenly. Place the mixture in a vacuum oven to remove the remaining bubbles. Pour the mixture into a preheated mold, keep it at 60 °C for 1 h, at 120 °C for 2 h, and at 180 °C for 2 h. Finally, slowly cool the mold to room temperature, take out the epoxy resin composite material, and the preparation process is shown in Figure 1 .
[0048] Analysis: The scanning electron microscope image of the fracture surface of the pure epoxy resin spline in the bending experiment shows a smooth surface and shallow cracks, showing obvious brittle fracture, which reflects the low toughness of the pure epoxy resin without adding a polymer modifier.
[0049] Example 1
[0050] At room temperature, 1.1505 g of p-terphenyl and 1.1505 g of m-terphenyl were added to a three-necked flask equipped with a mechanical stirrer. 2.5 mL of dichloromethane was added to dissolve them, and stirring was started at a speed of 150 rpm. Then, 1.5768 g of 4-acetylpyridine was added and stirred evenly. Ice was added to the water bath to provide an ice bath environment, maintaining a low temperature of 0 °C, and stirring was continued for a specific time. Then, 12 mL of trifluoromethanesulfonic acid was slowly added using a constant pressure dropping funnel to prevent excessive heat release. After the addition was completed, 0.55 mL of trifluoroacetic acid was added to reduce the acidity and raise the temperature to room temperature, and stirring was carried out for 4 h. At this time, the entire reaction system showed a dark blue homogeneous mucus. Before the reaction ended, 10 mL of dichloromethane was added to reduce the viscosity. The reaction mixture was precipitated with excess deionized water to obtain a pale yellow or white fibrous product, which was washed until the pH was neutral, and the product was dried. The dried product was dissolved in N-methylpyrrolidone to prepare a solution, and the solution was poured into methanol for precipitation to obtain a white fibrous product, which was then boiled 3 times with an electric heating mantle, filtered, and finally dried in a vacuum oven at 80 °C.
[0051] Take 1 g of the polymer additive synthesized above and dissolve it in chloroform, and stir until a homogeneous solution is obtained. Pour 39 g of epoxy resin E-51 into a separate beaker and stir at 60 °C to reduce its viscosity. Then the two solutions were mixed and the solvent was evaporated in a rotary evaporation device until the solvent was completely evaporated. After the solvent was completely evaporated, 5 g of curing agent m-phenylenediamine was added and stirred at 70 °C for 10 min until the curing agent was dissolved and mixed evenly. The mixture was placed in a vacuum oven to remove residual bubbles. The mixture was poured into a preheated mold, kept at 60 °C for 0.5 h, at 110 °C for 1 h, and at 170 °C for 1 h. Finally, the mold was slowly cooled to room temperature, and the epoxy resin composite material was taken out. The preparation process is shown in Figure 1 .
[0052] Analysis: Figure 2(a) is the nuclear magnetic resonance hydrogen spectrum of the polymer in this example. Figure 2(b) is a partial enlarged view of region A in Figure (a). The chemical shift at 7.18 - 7.80 ppm in the figure is attributed to the terphenyl fragment, while the chemical shift at 2.25 ppm is attributed to the methyl group on the pyridine structure. The chemical shifts at 8.53 ppm, 7.80 ppm, and 7.66 ppm are attributed to the protons on the pyridine ring, the protons on m-terphenyl, and the protons on p-terphenyl, respectively.
[0053] Example 2
[0054] At room temperature, 0.7711 g of biphenyl and 0.8311 g of fluorene were added to a three-necked flask equipped with a mechanical stirrer, and 2.5 mL of dichloromethane was added to dissolve them. Stirring was started at a speed of 150 rpm, and then 1.4710 g of N-methyl-4-piperidone was added and stirred evenly. Ice was added to the water bath to provide an ice bath environment, and the temperature was maintained at 0 °C, and stirring was continued for a specific time. Then, 12 mL of trifluoromethanesulfonic acid was slowly added using a constant pressure dropping funnel to prevent excessive heat release. After the addition was completed, 0.55 mL of trifluoroacetic acid was added to reduce the acidity and raise the temperature to room temperature, and stirring was carried out for 6 h. At this time, the entire reaction system showed a dark blue uniform mucus. Before the reaction ended, 10 mL of dichloromethane was added to reduce the viscosity. The reaction mixture was precipitated with excessive deionized water to obtain a pale yellow or white fibrous product, washed until the pH was neutral, and the product was dried. The dried product was dissolved in N-methylpyrrolidone to prepare a solution, and the solution was poured into methanol to precipitate, obtaining a white fibrous product, which was then boiled 3 times with an electric heating mantle, filtered, and finally dried in a vacuum oven at 80 °C.
[0055] Take 2 g of the polymer additive synthesized above and dissolve it in chloroform, and stir until a homogeneous solution is obtained. Pour 38 g of epoxy resin E-51 into a separate beaker and stir at 60 °C to reduce its viscosity. Then the two solutions were mixed and the solvent was evaporated in a rotary evaporator until the solvent was completely evaporated. After the solvent was completely evaporated, 4.9 g of the curing agent 4,4'-diaminodiphenyl sulfone was added and stirred at 70 °C for 10 min until the curing agent was dissolved and mixed evenly. The mixture was placed in a vacuum oven to remove residual bubbles. The mixture was poured into a preheated mold, kept at 65 °C for 1 h, at 120 °C for 2 h, and at 180 °C for 2 h. Finally, the mold was slowly cooled to room temperature and the epoxy resin composite material was taken out.
[0056] Analysis: Figure 3 It is a scanning electron microscope image of the fracture surface of an epoxy resin spline after a notched three-point bending test. It can be observed that the surface of the sample is uniform and no phase separation has occurred, indicating good compatibility between the polymer additive and the epoxy resin. At the same time, it can be clearly observed that the fracture surface is very rough, with a large number of wrinkles and shear bands appearing, indicating that the composite material undergoes plastic deformation when subjected to external force impact. These wrinkles and shear bands will absorb a large amount of energy, resist the propagation of cracks, and improve the toughness of the material.
[0057] Example 3
[0058] At room temperature, 0.6409 g of naphthalene and 1.5320 g of 1,3,5-triphenylbenzene were added to a three-necked flask equipped with a mechanical stirrer, and 2.5 mL of dichloromethane was added to dissolve them. Stirring was started at a speed of 150 rpm, and then 2.2636 g of 2,2,2-trifluoroacetophenone was added and stirred evenly. Ice was added to the water bath to provide an ice bath environment, and the low temperature was maintained at 0 °C, and stirring was continued for a specific time. Then, 12 mL of trifluoromethanesulfonic acid was slowly added using a constant pressure dropping funnel to prevent excessive heat release. After the dropping was completed, 0.55 mL of trifluoroacetic acid was added to reduce the acidity and raise the temperature to room temperature, and stirring was carried out for 8 h. At this time, the entire reaction system showed a dark blue uniform mucus. Before the reaction ended, 10 mL of dichloromethane was added to reduce the viscosity. The reaction mixture was precipitated with excess deionized water to obtain a pale yellow or white fibrous product, which was washed until the pH was neutral, and the product was dried. The dried product was dissolved in N-methylpyrrolidone to prepare a solution, and the solution was poured into methanol to precipitate, obtaining a white fibrous product, which was then boiled 3 times with an electric heating mantle, filtered, and finally dried in a vacuum oven at 80 °C.
[0059] Take 3 g of the polymer additive synthesized above and dissolve it in chloroform, and stir until a homogeneous solution is obtained. Pour 37 g of epoxy resin E-51 into a separate beaker and stir at 60 °C to reduce its viscosity. Then the two solutions were mixed and the solvent was evaporated in a rotary evaporation device until the solvent was completely evaporated. After the solvent was completely evaporated, 4.8 g of the curing agent m-phenylenediamine was added and stirred at 70 °C for 10 min until the curing agent was dissolved and mixed evenly. The mixture was placed in a vacuum oven to remove residual bubbles. The mixture was poured into a preheated mold, kept at 70 °C for 1.5 h, at 130 °C for 3 h, and at 190 °C for 3 h. Finally, the mold was slowly cooled to room temperature and the epoxy resin composite was taken out.
[0060] Analysis: The Fourier transform infrared spectrum of the polymer additive showed characteristic peaks at 3031 and 2974 cm -1 corresponding to aromatic and aliphatic C-H stretching vibrations, respectively. The peaks at 1590 and 1490 cm -1 were the C=N and C=C stretching vibrations of the aromatic group, respectively. The infrared absorption peaks in the range of 700 - 1000 cm -1 were the characteristic regions of benzene ring substitution, indicating the presence of para-substitution and meta-substitution of the benzene ring in the polymer. It is worth noting that the characteristic absorption C=O peak of 2,2,2-trifluoroacetophenone at 1720 cm -1 disappeared, indicating successful polymerization.
[0061] Example 4
[0062] At room temperature, 1.5320 g of p - terphenyl and 1.7122 g of triphenylene were added to a three - necked flask equipped with a mechanical stirrer. 2.5 mL of dichloromethane was added to dissolve them. Stirring was started at a speed of 150 rpm, and then 2.7313 g of 2',3',4',5',6' - pentafluoroacetophenone was added and stirred evenly. Ice was added to the water bath to provide an ice - bath environment, maintaining a low temperature of 0 °C, and stirring was continued for a specific time. Then, 12 mL of trifluoromethanesulfonic acid was slowly added using a constant - pressure dropping funnel to prevent excessive heat release. After the dropping was completed, 0.55 mL of trifluoroacetic acid was added to reduce the acidity and raise the temperature to room temperature, and stirring was carried out for 5 h. At this time, the entire reaction system presented as a dark - blue homogeneous mucus. Before the reaction ended, 10 mL of dichloromethane was added to reduce the viscosity. The reaction mixture was precipitated with excess deionized water to obtain a pale - yellow or white fibrous product, washed until the pH was neutral, and the product was dried. The dried product was dissolved in N - methylpyrrolidone to prepare a solution, and the solution was poured into methanol for precipitation to obtain a white fibrous product, which was then boiled 3 times using an electric heating mantle, filtered, and finally dried in a vacuum oven at 80 °C.
[0063] Take 4 g of the polymer additive synthesized above and dissolve it in chloroform, and stir until a homogeneous solution is obtained. Pour 36 g of epoxy resin E - 51 into a separate beaker and stir at 60 °C to reduce its viscosity. Then the two solutions are mixed, and the solvent is evaporated in a rotary evaporation device until the solvent is completely evaporated. After the solvent is completely evaporated, 4.7 g of the curing agent 4,4' - diaminodiphenylsulfone is added, and stirring is carried out at 70 °C for 10 min until the curing agent is dissolved and mixed evenly. The mixture is placed in a vacuum oven to remove the remaining bubbles. The mixture is poured into a pre - heated mold, kept at 65 °C for 1 h, at 120 °C for 2 h, and at 180 °C for 2 h. Finally, the mold is slowly cooled to room temperature, and the epoxy resin composite material is taken out.
[0064] Analysis: For the nuclear magnetic resonance hydrogen spectrum of the polymer, the chemical shift at 7.18 - 7.80 ppm in the spectrum is attributed to the terphenyl fragment, while the chemical shift at 2.25 ppm is attributed to the methyl group on 2',3',4',5',6' - pentafluoroacetophenone. The chemical shifts at 8.53 ppm, 7.80 ppm, and 7.66 ppm are attributed to the protons on the fluorine - free pyridine ring, the protons on triphenylene, and the protons on p - terphenyl, respectively.
[0065] Example 5
[0066] At room temperature, 0.8911 g of anthracene and 2.6713 g of hexaphenylbenzene were added to a three-necked flask equipped with a mechanical stirrer. 2.5 mL of dichloromethane was added to dissolve them. Stirring was started at a speed of 150 rpm, and then 1.6403 g of 2-acetylthiophene was added and stirred evenly. Ice was added to the water bath to provide an ice bath environment, maintaining a low temperature of 0 °C, and stirring continued for a specific time. Then, 12 mL of trifluoromethanesulfonic acid was slowly added using a constant-pressure dropping funnel to prevent excessive heat release. After the addition was complete, 0.55 mL of trifluoroacetic acid was added to reduce the acidity and raise the temperature to room temperature, and stirring was carried out for 7 h. At this time, the entire reaction system showed a dark blue homogeneous mucus. Before the reaction ended, 10 mL of dichloromethane was added to reduce the viscosity. The reaction mixture was precipitated with excess deionized water to obtain a pale yellow or white fibrous product, which was washed until the pH was neutral, and the product was dried. The dried product was dissolved in N-methylpyrrolidone to prepare a solution, and the solution was poured into methanol for precipitation to obtain a white fibrous product, which was then boiled 3 times using an electric heating mantle, filtered, and finally dried in a vacuum oven at 80 °C.
[0067] Take 2 g of the polymer additive synthesized above and dissolve it in chloroform, and stir until a homogeneous solution is obtained. Pour 38 g of epoxy resin E-51 into a separate beaker and stir at 60 °C to reduce its viscosity. Then the two solutions were mixed and the solvent was evaporated in a rotary evaporation device until the solvent was completely evaporated. After the solvent was completely evaporated, 4.9 g of the curing agent m-phenylenediamine was added and stirred at 70 °C for 10 min until the curing agent was dissolved and mixed evenly. The mixture was placed in a vacuum oven to remove residual bubbles. The mixture was poured into a preheated mold, held at 65 °C for 1 h, at 120 °C for 2 h, and at 180 °C for 2 h. Finally, the mold was slowly cooled to room temperature and the epoxy resin composite was taken out.
[0068] Analysis: The tensile strength, Young's modulus, fracture toughness, and critical strain energy release rate of the epoxy resin composites in the above 5 examples and the control example are shown in Figure 4 and Figure 5 , and the statistical results are shown in the following table:
[0069] Comparative Example Example 1 Example 2 Example 3 Example 4 Example 5 Tensile Strength 56.5 MPa 65.25 MPa 69.2 MPa 74.3 MPa 83.5 MPa 75.54 MPa Young's Modulus 1110 MPa 1310.9 MPa 1387.9 MPa 1574.6 MPa 1627.4 MPa 1479.4 MPa Fracture Toughness <![CDATA[0.9MPa·m 1 / 2 > <![CDATA[1.32MPa·m 1 / 2 > <![CDATA[1.53MPa·m 1 / 2 > <![CDATA[1.65MPa·m 1 / 2 > <![CDATA[1.81MPa·m 1 / 2 > <![CDATA[2.03MPa·m 1 / 2 > Critical Strain Energy Release Rate <![CDATA[0.23KJ·m -2 > <![CDATA[0.4KJ·m -2 > <![CDATA[0.58KJ·m -2 > <![CDATA[0.73KJ·m -2 > <![CDATA[0.82KJ·m -2 > <![CDATA[1.07KJ·m -2 >
[0070] Tensile strength reflects the maximum stress that a material can withstand when subjected to a tensile force; Young's modulus is a physical quantity that describes the ability of a solid material to resist deformation; fracture toughness characterizes the ability of a material to prevent crack propagation and is a quantitative index to measure the toughness of a material; the critical energy release rate refers to the strain energy that can be released when the crack of a deformed object expands per unit area. The high-performance epoxy resins prepared in Examples 1-5 above all exhibited good strength and toughness, showing a very obvious improvement compared with the pure epoxy resin in the control example.
[0071] The above-described embodiments merely represent the implementation manners of the present invention, but should not be construed as limiting the scope of the patent of the present invention. It should be noted that for those skilled in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all fall within the protection scope of the present invention.
Claims
1. A high performance epoxy resin, characterized in that: The high-performance epoxy resin is prepared by physically blending an epoxy resin prepolymer and a polymer additive. The polymer additive is composed of a rigid aromatic structure monomer Ar1, a twisted aromatic structure monomer Ar2 and a functional structure monomer R2. The structural formula of the polymer additive is as follows: Wherein, x is the molar proportion of the rigid aromatic structural unit in the polymer chain, %; y is the molar proportion of the twisted aromatic structural unit in the polymer chain, %; x is 10% to 50%, and y is 50% to 90%.
2. A high performance epoxy resin according to claim 1, characterized in that: In the polymer additive: The structure of Ar1 is at least one of the following: The structure of Ar2 is at least one of the following: Wherein, R1 in the Ar2 structure is hydrogen or a C1-C10 alkyl group; The structure of R2 is at least one of the following:
3. A method for preparing the high performance epoxy resin according to claim 1 or 2, characterized in that: The steps include: Step 1: Synthesis of polymer additives; Step 1.1, at room temperature, adding monomers to solvent A, stirring and dissolving, and then adding functional monomer R2, continuing to stir evenly, reacting for 4 to 8 hours to obtain a mixed solution; the monomers include rigid aromatic structure monomers Ar1 and twisted aromatic structure monomers Ar2; Step 1.2, in an ice bath environment, slowly add strong acid A to the mixed solution using a constant pressure dropping funnel, then add acid B to reduce the acidity, then continue to raise the temperature to room temperature, stir and react for 4 to 8 hours to obtain a blue uniform viscous solution; Step 1.3, after the reaction is completed, solvent A is added to reduce the viscosity, and the reaction mixture is precipitated with an excess of solvent B to obtain a light yellow or white fibrous product, which is washed to a neutral pH and dried; the dried product is dissolved in solvent C to prepare a solution, and the solution is poured into solvent B for precipitation to obtain a white fibrous product, which is post-treated to obtain a polymer additive; Step 2: Preparation of epoxy resin composite material; Step 2.1, dissolving the polymer additive synthesized in step 1 in solvent D, and stirring until a uniform solution is obtained; Step 2.2, pouring the viscous epoxy resin into a separate beaker, and heating and stirring at 60-80° C. to reduce its viscosity, thereby obtaining a liquid epoxy resin; Step 2.3, mixing the two solutions obtained in step 2.1 and step 2.2, and evaporating the solvent in a rotary evaporator until the solvent D is completely evaporated; after the solvent is completely evaporated, adding a curing agent, and stirring at 70° C. for 10 minutes until the curing agent is dissolved and mixed evenly; Step 2.4, placing the mixture obtained in step 2.3 in a vacuum oven to remove residual bubbles; pouring the mixture into a preheated mold, keeping it at 60-70° C. for 0.5-1.5 h, keeping it at 110-130° C. for 1-3 h, and keeping it at 170-190° C. for 1-3 h; Step 2.5, slowly cool the mold to room temperature and take out the epoxy resin composite material.
4. The method for preparing a high-performance epoxy resin according to claim 3, characterized in that: In the step 1, the molar ratio of the three monomers Ar1, Ar2 and R2 is 1:(0.8-1):(2-3); and the total molar concentration of the three monomers in solvent A is 2-6 mol / L.
5. The method for preparing a high-performance epoxy resin according to claim 4, characterized in that: In the step 1, the molar ratio of the three monomers Ar1, Ar2 and R2 is preferably 1:1:2.5; the total molar concentration of the three monomers in solvent A is preferably 4 mol / L.
6. The method for preparing a high-performance epoxy resin according to claim 3, characterized in that: In the step 1, the volume ratio of the strong acid A to the acid B is 1:(0.033-0.05); The stirring speed is 100-200 rpm, and the reaction time is preferably 6 hours; The low temperature range of the ice bath environment is 0 to 5°C; The solvent A is one of dichloromethane, chloroform, toluene and tetrahydrofuran; the solvent B is one of deionized water, methanol, ethanol, ethyl acetate, saturated sodium carbonate solution and saturated sodium bicarbonate solution; the solvent C is one of N-methylpyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, tetrahydrofuran and dichloromethane; the super acid A is one of trifluoromethanesulfonic acid, fluorosulfonic acid, carborane acid and perfluorobutylsulfonic acid; the acid B is one of trifluoroacetic acid, trichloroacetic acid and methanesulfonic acid.
7. The method for preparing a high-performance epoxy resin according to claim 6, characterized in that: In the step 1, the solvent A is preferably dichloromethane; the solvent B is preferably deionized water; the solvent C is preferably N-methylpyrrolidone; the superacid A is preferably trifluoromethanesulfonic acid; and the acid B is preferably trifluoroacetic acid.
8. The method for preparing a high performance epoxy resin according to claim 3, characterized in that: In the step 2: the solvent D is one of dichloromethane, chloroform and tetrahydrofuran; The epoxy resin is a mixture of one or more of epoxy resin E-51, epoxy resin E-44 and epoxy resin E-42; The curing agent is one of m-phenylenediamine, 4,4'-diaminodiphenyl sulfone, phthalic anhydride and pyromellitic dianhydride; The mass ratio of the epoxy resin to the polymer additive is 100:(0-12); The mass ratio of the epoxy resin to the curing agent is 100:(10-15).
9. The method for preparing a high-performance epoxy resin according to claim 8, characterized in that: In the step 2: the solvent D is preferably chloroform; The epoxy resin is preferably epoxy resin E-51; The curing agent is preferably m-phenylenediamine.
10. The method for preparing a high-performance epoxy resin according to claim 8, characterized in that: In the step 2: the mass ratio of the epoxy resin to the polymer additive is preferably 100:6; The mass ratio of the epoxy resin to the curing agent is preferably 100:13.