High-temperature-resistant epoxy resin composite material and preparation method thereof

Abstract

The invention discloses a high-temperature-resistant epoxy resin composite material and a preparation method thereof, and relates to the technical field of composite materials. The high-temperature-resistant epoxy resin composite material is prepared from the following raw materials in parts by weight: 70 to 80 parts of modified epoxy resin, 8 to 15 parts of high-temperature-resistant modifier, 15 to 30 parts of curing agent, 3 to 8 parts of nano reinforcing filler, 1 to 3 parts of coupling agent, 3 to 6 parts of carbon fiber, 2 to 5 parts of nano titanium dioxide, 5 to 10 parts of organic silicon rubber, 1 to 3 parts of conductive agent, 3 to 7 parts of flame retardant and 2 to 4 parts of zinc borate. The high-temperature-resistant epoxy resin composite material has outstanding advantages and strong thermal stability, and can bear high temperature; mechanical performance is excellent, and firmness and durability are achieved; the self-repairing capability is achieved, and the service cycle can be prolonged; the anti-permeability is good, and gas and liquid can be effectively blocked; the surface is smooth, the friction coefficient is low and the application prospect is wide.

Description

Technical Field

[0001] The invention relates to the technical field of composite materials, in particular to a high temperature resistant epoxy resin composite material and a preparation method thereof. Background Art

[0002] In today's era of booming science and technology, high-performance composite materials play an irreplaceable role in many key fields. Epoxy resin, as a widely used thermosetting resin, is favored in the aerospace, electronic information, automobile manufacturing and other industries due to its excellent adhesion, good mechanical properties and excellent chemical stability. However, with the continuous increase in material performance requirements in various fields, the shortcomings of ordinary epoxy resin in high temperature resistance have gradually become apparent.

[0003] In the aerospace field, when an aircraft flies at high altitude and high speed, a large amount of heat will be generated on the surface of the aircraft due to air friction, and key components such as the engine will also be in a high temperature environment for a long time, which requires the materials used to have excellent high temperature resistance. In electronic equipment, with the continuous improvement of integration, the heat generated by electronic components has increased dramatically. If the material is not resistant to high temperatures, the stability of the electronic equipment will decrease and the service life will be shortened.

[0004] In order to overcome the defects of epoxy resin's high temperature resistance, researchers have conducted many explorations. Traditional methods such as simply increasing the amount of curing agent can improve heat resistance to a certain extent, but it will increase the brittleness of the material and deteriorate the overall performance; adding ordinary inorganic fillers is prone to uneven dispersion problems, affecting the improvement of material performance. Existing high temperature resistant modification technologies often have the disadvantages of complex processes, high costs and difficulty in large-scale industrial production. Therefore, the development of an epoxy resin composite material with excellent high temperature resistance, reasonable cost and simple preparation process has become an important issue that needs to be urgently solved in the field of materials. Summary of the invention

[0005] In view of the deficiencies in the prior art, the present invention provides a high-temperature resistant epoxy resin composite material and a preparation method thereof, which solves the problems that traditional epoxy resin materials are not resistant to high temperatures, are susceptible to chemical corrosion, and cannot be repaired.

[0006] To achieve the above objectives, the present invention is implemented through the following technical solutions: A high temperature resistant epoxy resin composite material comprises the following raw materials in parts by weight: 70-80 parts of modified epoxy resin, 8-15 parts of high temperature resistant modifier, 15-30 parts of curing agent, 3-8 parts of nano-reinforced filler, 1-3 parts of coupling agent, 3-6 parts of carbon fiber, 2-5 parts of nano titanium dioxide, 5-10 parts of silicone rubber, 1-3 parts of conductive agent, 3-7 parts of flame retardant and 2-4 parts of zinc borate.

[0007] Furthermore, the modified epoxy resin comprises the following raw materials in parts by weight: 50-60 parts of bisphenol A-bisphenol F type mixed epoxy resin YLF-1700F, 15-20 parts of 4,4'-diaminodiphenyl sulfone curing agent, 3-5 parts of nanometer montmorillonite, 20-30 parts of toluene solution containing 10% cetyltrimethylammonium bromide, 10-15 parts of dicyclopentadiene, 1-3 parts of Grubbs catalyst, 10-20 parts of cyclohexane, 8-15 parts of isophthaloyl chloride, 2-4 parts of hexamethylenediamine, 2-5 parts of perfluorooctanoic acid acetone solution, 10-15 parts of low molecular weight polyamide, 2-5 parts of nanometer SiO2, 5-10 parts of silane coupling agent KH-560, 1-3 parts of PTFE micropowder; The specific preparation steps of the modified epoxy resin are as follows: A1. Put the nanometer montmorillonite into a vacuum drying oven and dry it at 100-120°C for 1-3 hours. After drying, add the nanometer montmorillonite into toluene containing cetyltrimethylammonium bromide and ultrasonically disperse it for 30-50 minutes to complete the organic treatment; put the nanometer silicon dioxide into a vacuum drying oven and dry it at 80-100°C for 1-2 hours. After drying, add the nanometer SiO2 into an ethanol solution containing silane coupling agent KH-560 and ultrasonically disperse it with an ultrasonic disperser for 40-60 minutes to complete the surface modification; dissolve the dicyclopentadiene and Grubbs catalyst in cyclohexane, and at the same time dissolve the isophthaloyl chloride and hexamethylenediamine in the aqueous phase and the oil phase respectively, and carry out emulsifying stirring at a rotation speed of 800-1200 r / min, and slowly drop the oil phase into the aqueous phase to prepare microcapsules encapsulating the repair agent; A2. Add the bisphenol A-bisphenol F type mixed epoxy resin into a three-necked flask equipped with a stirrer, a thermometer and a condenser tube, slowly heat it to 80-90°C, stir at a rotation speed of 200-300 r / min, and slowly and evenly add the DDS curing agent and the organic nanometer montmorillonite. After adding, continue to stir for 30-60 minutes; A3. Control the temperature of the above system at 60-70°C, and the stirring speed is 100-200 r / min. Drop the perfluorooctanoic acid acetone solution at a rate of 1-3 mL per minute through a constant pressure dropping funnel. After dropping, continue to stir for 20-40 minutes; transfer the system to a rotary evaporator and heat it to 80-90°C under a reduced pressure condition of 40-50 kPa; A4. Pour the epoxy resin system after the second modification into a three-necked flask, heat it to 70 - 75 °C, and slowly add low molecular weight polyamide while stirring at a speed of 200 - 300 r / min. After adding, continue stirring for 40 - 60 minutes; then add surface-modified nano-SiO₂ and continue stirring for 30 - 50 minutes; lower the temperature to 60 - 65 °C, slowly add PTFE micropowder and microcapsules containing the repair agent, and continue stirring for 1 - 2 hours. Finally, transfer the mixture to a vacuum dryer and defoam it for 30 - 50 minutes in a vacuum environment of -0.08 MPa to -0.12 MPa to obtain the modified epoxy resin.

[0008] Furthermore, the high-temperature resistant modifier comprises the following raw materials in parts by weight: 5 - 10 parts of dichlorophenylphosphonic acid, 8 - 15 parts of γ-aminopropyltriethoxysilane, 1 - 3 parts of anhydrous aluminum trichloride, and 30 - 50 parts of toluene. The specific preparation method of the high-temperature resistant modifier is as follows: B1. Add toluene and anhydrous aluminum trichloride into a four-necked flask, turn on the stirrer, and stir at a speed of 300 - 500 r / min. After anhydrous aluminum trichloride is completely dissolved, add the phosphorus-containing compound dichlorophenylphosphonic acid dropwise into the four-necked flask at a dropping rate of 1 - 3 mL per minute. After dropping, raise the temperature of the reaction system to 80 - 90 °C and keep stirring at this temperature for 1 - 2 hours to form an active intermediate. B2. Under stirring conditions, add the silicon-containing compound γ-aminopropyltriethoxysilane dropwise through a dropping funnel at a speed of 1 - 3 mL per minute while maintaining the reaction temperature at 80 - 90 °C. After dropping, continue stirring and reacting at 80 - 90 °C for 1 - 2 hours to generate a phosphorus-silicon hybrid compound. B3. After the reaction is completed, cool the reaction system to room temperature, then transfer it to a separatory funnel, add deionized water to the separatory funnel, shake it and let it stand for stratification, discard the lower aqueous phase, and repeat this operation 3 - 5 times; transfer the separated organic phase to a distillation flask, and use a rotary evaporator to distill off the toluene solvent at 1 - 4 kPa to obtain a crude product. Then, recrystallize the crude product with absolute ethanol, filter and collect the crystals, and dry them in a vacuum drying oven at 50 - 60 °C for 2 - 3 hours to obtain a pure phosphorus-silicon hybrid compound, namely the high-temperature resistant modifier.

[0009] Furthermore, the curing agent is one of phthalic anhydride, methyltetrahydrophthalic anhydride, and 4,4'-diaminodiphenylmethane.

[0010] Furthermore, the nano-enhanced filler is surface-treated nano-boron nitride.

[0011] Furthermore, the coupling agent is a compound of amino-silane coupling agent and titanate coupling agent in a ratio of 1:1.

[0012] Further, the conductive agent is one of carbon nanotubes, graphene nanosheets, and conductive carbon black.

[0013] Further, the flame retardant is one of expanded vermiculite, aluminum hydroxide, and melamine cyanurate.

[0014] A preparation method of a high-temperature resistant epoxy resin composite material specifically includes the following steps: S1. Oxidize carbon fiber with 3% nitric acid solution at 60 °C for 2 hours to enhance surface activity, then rinse it with deionized water until neutral and dry it, and cut the treated carbon fiber into 3 mm lengths; Disperse nano-titanium dioxide in absolute ethanol and ultrasonically disperse it for 60 minutes to form a uniform suspension; Add a silane coupling agent KH–550 to the flame retardant in a high-speed mixer and stir for 30 minutes to obtain a surface-treated flame retardant. S2. Add the modified epoxy resin to the reaction kettle, slowly raise the temperature to 70 - 80 °C, set the stirring speed to 600 - 800 r / min until the epoxy resin melts completely into a uniform liquid state, add the coupling agent, increase the stirring speed to 900 - 1000 r / min, and stir for 45 - 60 minutes; Add the pretreated carbon fiber and nano-titanium dioxide suspension to the reaction kettle and stir at a high speed of 900 - 1000 r / min for 40 - 60 minutes; Slowly add the nano-enhanced filler to the system, ultrasonically disperse it for 15 - 30 minutes, and then continue to stir at a speed of 600 - 800 r / min for 30 - 50 minutes; Add hollow ceramic microspheres to the reaction kettle and continue to stir for 30 - 50 minutes. S3. Reduce the speed to 300 - 500 r / min, add the high-temperature resistant modifier to the above system, and keep stirring at this speed for 30 - 45 minutes. During the stirring process, raise the temperature in the reaction kettle to 80 - 90 °C; Add the silicone rubber plastified at 60 °C for 30 minutes to the reaction kettle and stir for 40 - 60 minutes; Then add the conductive agent, surface-treated flame retardant, and zinc borate, and continue to stir for 30 - 40 minutes; Add the curing agent to the system, increase the stirring speed to 500 - 800 r / min, and stir for 10 - 15 minutes. S4. Quickly inject the uniformly stirred mixed material into the mold, then place the mold in an oven and pre-cure it at 90 - 110 °C for 2 - 3 hours. After the curing is completed, raise the oven temperature to 160 - 180 °C for post-curing for 3 - 4 hours. After the post-curing is completed, turn off the heating equipment and let the mold cool naturally in the oven to room temperature. Take out the composite material from the mold to obtain the final high-temperature resistant epoxy resin composite material product.

[0015] The present invention provides a high-temperature resistant epoxy resin composite material and its preparation method, having the following beneficial effects: 1. During the preparation process, dichlorophenylphosphine reacts with γ-aminopropyltriethoxysilane under the catalysis of anhydrous aluminum trichloride to produce a phosphorus-silicon hybrid compound. The phosphorus-silicon bond it contains is very stable at high temperatures and can form a stable cross-linked structure, effectively restricting the thermal movement of molecular chains. When the material is in a high-temperature environment, this cross-linked structure is like a strong "molecular framework", preventing the molecular chains from shifting and breaking due to thermal movement, thus significantly increasing the thermal decomposition temperature and glass transition temperature of the composite material and enabling it to maintain stable physical and chemical properties at high temperatures.

[0016] 2. On the one hand, the surface-treated nano boron nitride and epoxy resin form a firm chemical bond connection through a coupling agent. The amino silane coupling agent and titanate coupling agent are compounded in a ratio of 1:1, acting as a bridge between the two and improving the interfacial compatibility. When the material is subjected to external forces, the stress can be evenly transmitted through these chemical bonds, avoiding stress concentration. On the other hand, the added components such as carbon fiber and silicone rubber further optimize the microstructure of the material. Carbon fiber, with its high strength and high modulus characteristics, forms a reinforcing framework inside the composite material, enhancing the tensile strength and flexural strength; the long-chain structure of silicone rubber endows the material with flexibility and impact resistance. These multiple microstructures cooperate with each other, greatly enhancing the comprehensive mechanical properties of the material.

[0017] 3. Dicyclopentadiene, isophthaloyl chloride and hexamethylenediamine react to prepare microcapsules encapsulating a repair agent, which are uniformly dispersed in the composite material. When tiny cracks appear in the material, the crack propagation will cause the microcapsules to rupture and release the repair agent. Under the action of the curing agent in the system, the repair agent rapidly undergoes a polymerization reaction, filling the cracks and re-crosslinking and curing. This process is like a "miniature repair factory" inside the material, which can timely repair the cracks, restore the structural integrity of the material, thus extending the service life of the material, reducing the maintenance cost and improving the reliability of the material.

[0018] 4. Nano montmorillonite has a lamellar structure and can form tortuous channels in the epoxy resin matrix. When gases or liquids attempt to penetrate, they need to move along these tortuous paths, greatly increasing the difficulty of penetration. At the same time, nano-SiO2 is filled in the tiny pores of the material, further increasing the density of the material. The two act synergistically to effectively hinder the penetration of gases and liquids, reducing the permeability of the composite material and making it have good application prospects in fields such as waterproof, anti-corrosion coatings and sealing materials.

[0019] 5. During the preparation process, PTFE micro powder is evenly dispersed inside the composite material. After the material is formed, the PTFE micro powder will migrate to the surface of the material. PTFE has an extremely low coefficient of friction, making the surface of the composite material extremely smooth. This smooth surface can not only reduce the frictional resistance of the material during use and reduce energy consumption, but also effectively prevent the attachment of dirt, dust, etc., and has obvious advantages in the fields of architectural decoration, automotive exterior decoration, etc. Detailed implementation mode

[0020] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

[0021] Embodiment 1 A high-temperature resistant epoxy resin composite material, comprising the following raw materials in parts by weight: 70 parts of modified epoxy resin, 8 parts of high-temperature resistant modifier, 15 parts of curing agent, 3 parts of nano-enhancing filler, 1 part of coupling agent, 3 parts of carbon fiber, 2 parts of nano-titanium dioxide, 5 parts of silicone rubber, 1 part of conductive agent, 3 parts of flame retardant, and 2 parts of zinc borate.

[0022] A preparation method of a high-temperature resistant epoxy resin composite material specifically comprises the following steps: S1. Oxidize the carbon fiber with 3% nitric acid solution at 60 °C for 2 hours to enhance the surface activity, then rinse it with deionized water until neutral and dry it, and cut the treated carbon fiber into 3 mm in length; Disperse the nano-titanium dioxide in absolute ethanol and ultrasonically disperse it for 60 minutes to form a uniform suspension; Add the silane coupling agent KH-550 to the expanded vermiculite in a high-speed mixer and stir for 30 minutes to obtain surface-treated expanded vermiculite; S2. Add the modified epoxy resin to the reaction kettle, slowly heat up to 70-80 °C, set the stirring speed to 600 r / min until the epoxy resin melts completely into a uniform liquid state, add the coupling agent, increase the stirring speed to 900 r / min, and stir for 45 minutes; Add the pretreated carbon fiber and nano-titanium dioxide suspension to the reaction kettle and stir at a high speed of 900 r / min for 40 minutes; Slowly add the nano-enhancing filler to the system, ultrasonically disperse it for 15 minutes, and then continuously stir at a speed of 600 r / min for 30 minutes; Add the hollow ceramic microspheres to the reaction kettle and continue to stir for 30 minutes; S3. Reduce the rotational speed to 300 r / min, add the high-temperature resistant modifier to the above system, stir at this rotational speed for 30 minutes, and during the stirring process, raise the temperature in the reaction kettle to 80 °C; add the silicone rubber that has been plasticized at 60 °C for 30 minutes to the reaction kettle and stir for 40 minutes; then add carbon nanotubes, surface-treated expanded vermiculite, and zinc borate, and continue to stir for 30 minutes; add phthalic anhydride to the system, increase the stirring speed to 500 r / min, and stir for 10 minutes; S4. Quickly inject the uniformly stirred mixed material into the mold, then place the mold in an oven, pre-cure at 90 °C for 2 hours, after the curing is completed, raise the oven temperature to 160 °C, and carry out post-curing for 3 hours. After the post-curing is completed, turn off the heating equipment, let the mold cool naturally in the oven to room temperature, take out the composite material from the mold, and obtain the final high-temperature resistant epoxy resin composite product.

[0023] The modified epoxy resin contains the following raw materials in parts by weight: 50 parts of bisphenol A-bisphenol F type mixed epoxy resin YLF-1700F, 15 parts of 4,4'-diaminodiphenyl sulfone curing agent, 3 parts of nano-montmorillonite, 20 parts of toluene solution containing 10% cetyltrimethylammonium bromide, 10 parts of dicyclopentadiene, 1 part of Grubbs catalyst, 10 parts of cyclohexane, 8 parts of isophthaloyl chloride, 2 parts of hexamethylenediamine, 2 parts of perfluorooctanoic acid acetone solution, 10 parts of low molecular weight polyamide, 2 parts of nano-SiO2, 5 parts of silane coupling agent KH-560, 1 part of PTFE micropowder; The specific preparation steps of the modified epoxy resin are as follows: A1. Put the nano-montmorillonite into a vacuum drying oven and dry it at 100 °C for 1 hour. After the drying treatment, add the nano-montmorillonite to the toluene containing cetyltrimethylammonium bromide and perform ultrasonic dispersion for 30 minutes to complete the organic modification; put the nano-silica into a vacuum drying oven and dry it at 80 °C for 1 hour. After the drying treatment, add the nano-SiO2 to the ethanol solution containing the silane coupling agent KH-560 and use an ultrasonic disperser to perform ultrasonic dispersion for 40 minutes to complete the surface modification; dissolve the dicyclopentadiene and Grubbs catalyst in cyclohexane, and at the same time dissolve the isophthaloyl chloride and hexamethylenediamine in the aqueous phase and the oil phase respectively, perform emulsification stirring at a rotational speed of 800 r / min, and slowly drop the oil phase into the aqueous phase to prepare microcapsules encapsulating the repair agent; A2. Add the bisphenol A-bisphenol F type mixed epoxy resin to a three-necked flask equipped with a stirrer, a thermometer, and a condenser, slowly heat it to 80 °C, stir at a rotational speed of 200 r / min, slowly and uniformly add the DDS curing agent and the organic modified nano-montmorillonite, and continue to stir for 30 minutes after adding; A3. Control the temperature of the above system at 60 °C, with a stirring speed of 100 r / min. Dropwise add the perfluorooctanoic acid acetone solution at a rate of 1 mL per minute through a constant-pressure dropping funnel. After the addition is complete, continue stirring for 20 minutes. Transfer the system to a rotary evaporator and heat it to 80 °C under a reduced pressure of 40 kPa. A4. Pour the epoxy resin system after the second modification into a three-necked flask, heat it to 70 °C, and slowly add low molecular weight polyamide while stirring at a speed of 200 r / min. After the addition is complete, continue stirring for 40 minutes. Then add surface-modified nano-SiO2 and continue stirring for 30 minutes. When the temperature drops to 60 °C, slowly add PTFE micro-powder and microcapsules containing a repair agent, and continue stirring for 1 hour. Finally, transfer the mixture to a vacuum dryer and defoam it for 30 minutes in a vacuum environment of -0.08 MPa to obtain the modified epoxy resin.

[0024] The high-temperature resistant modifier comprises the following raw materials in parts by weight: 5 parts of phenylphosphonic dichloride, 8 parts of γ-aminopropyltriethoxysilane, 1 part of anhydrous aluminum trichloride, and 30 parts of toluene. The specific preparation method of the high-temperature resistant modifier is as follows: B1. Add toluene and anhydrous aluminum trichloride into a four-necked flask, turn on the stirrer, and stir at a speed of 300 r / min. After anhydrous aluminum trichloride is completely dissolved, add the phosphorus-containing compound phenylphosphonic dichloride into the four-necked flask at a dropping rate of 1 mL per minute. After the addition is complete, raise the temperature of the reaction system to 80 °C and keep stirring at this temperature for 1 hour to form an active intermediate. B2. Under stirring conditions, dropwise add the silicon-containing compound γ-aminopropyltriethoxysilane at a rate of 1 mL per minute through a dropping funnel while maintaining the reaction temperature at 80 °C. After the addition is complete, continue stirring and reacting at 80 °C for 1 hour to generate a phosphorus-silicon hybrid compound. B3. After the reaction is completed, cool the reaction system to room temperature, then transfer it to a separatory funnel, add deionized water to the separatory funnel, shake it and let it stand for stratification, discard the lower aqueous phase, and repeat this operation 3 times. Transfer the separated organic phase to a distillation flask, and use a rotary evaporator to distill off the toluene solvent at 1 kPa to obtain a crude product. Then recrystallize the crude product with absolute ethanol, filter and collect the crystals, and dry them in a vacuum drying oven at 50 °C for 2 hours to obtain a pure phosphorus-silicon hybrid compound, namely the high-temperature resistant modifier.

[0025] Example 2 A high-temperature resistant epoxy resin composite material comprises the following raw materials in parts by weight: 80 parts of modified epoxy resin, 15 parts of high-temperature resistant modifier, 30 parts of curing agent, 8 parts of nano-enhancing filler, 3 parts of coupling agent, 6 parts of carbon fiber, 5 parts of nano-titanium dioxide, 10 parts of silicone rubber, 3 parts of conductive agent, 7 parts of flame retardant, and 4 parts of zinc borate.

[0026] A preparation method of a high-temperature resistant epoxy resin composite material specifically comprises the following steps: S1. Oxidize carbon fiber with 3% nitric acid solution at 60 °C for 2 hours to enhance surface activity, then rinse it with deionized water until neutral and dry it, and cut the treated carbon fiber into 3 mm lengths; Disperse nano-titanium dioxide in absolute ethanol and ultrasonically disperse it for 60 minutes to form a uniform suspension; Add silane coupling agent KH–550 to aluminum hydroxide in a high-speed mixer and stir for 30 minutes to obtain surface-treated aluminum hydroxide; S2. Add the modified epoxy resin into a reaction kettle, slowly raise the temperature to 80 °C, set the stirring speed to 800 r / min until the epoxy resin melts completely into a uniform liquid state, add a coupling agent, increase the stirring speed to 1000 r / min, and stir for 60 minutes; Add the pretreated carbon fiber and nano-titanium dioxide suspension into the reaction kettle and stir at a high speed of 1000 r / min for 60 minutes; Slowly add nano-enhanced filler into the system, ultrasonically disperse it for 30 minutes, and then continuously stir at a speed of 800 r / min for 50 minutes; Add hollow ceramic microspheres into the reaction kettle and continue to stir for 50 minutes; S3. Reduce the speed to 500 r / min, add a high-temperature resistant modifier into the above system, keep stirring at this speed for 45 minutes, and during the stirring process, raise the temperature in the reaction kettle to 90 °C; Add the silicone rubber plastified at 60 °C for 30 minutes into the reaction kettle and stir for 60 minutes; Then add graphene nanosheets, surface-treated aluminum hydroxide and zinc borate, and continue to stir for 40 minutes; Add methyltetrahydrophthalic anhydride into the system, increase the stirring speed to 800 r / min, and stir for 15 minutes; S4. Quickly inject the uniformly stirred mixed material into a mold, then put the mold into an oven, pre-cure it at 110 °C for 3 hours, after the curing is completed, raise the oven temperature to 180 °C for post-curing for 4 hours, after the post-curing is completed, turn off the heating equipment, let the mold cool naturally in the oven to room temperature, and take out the composite material from the mold to obtain the final high-temperature resistant epoxy resin composite material product.

[0027] The modified epoxy resin contains the following raw materials in parts by weight: 60 parts of bisphenol A-bisphenol F type mixed epoxy resin YLF-1700F, 20 parts of 4,4'-diaminodiphenyl sulfone curing agent, 5 parts of nano-montmorillonite, 30 parts of toluene solution containing 10% cetyltrimethylammonium bromide, 15 parts of dicyclopentadiene, 3 parts of Grubbs catalyst, 20 parts of cyclohexane, 15 parts of isophthaloyl chloride, 4 parts of hexamethylenediamine, 5 parts of perfluorooctanoic acid acetone solution, 15 parts of low molecular weight polyamide, 5 parts of nano-SiO2, 10 parts of silane coupling agent KH-560, 3 parts of PTFE micro-powder; The specific preparation steps of the modified epoxy resin are as follows: A1. Put the nano-montmorillonite into a vacuum drying oven and dry it at 120 °C for 3 hours. After the drying treatment, add the nano-montmorillonite to toluene containing cetyltrimethylammonium bromide and ultrasonically disperse it for 50 minutes to complete the organic treatment; put the nano-silica into a vacuum drying oven and dry it at 100 °C for 2 hours. After the drying treatment, add the nano-SiO₂ to an ethanol solution containing the silane coupling agent KH-560 and ultrasonically disperse it with an ultrasonic disperser for 60 minutes to complete the surface modification; dissolve dicyclopentadiene and Grubbs catalyst in cyclohexane. At the same time, dissolve isophthaloyl chloride and hexamethylenediamine in the aqueous phase and the oil phase respectively, and carry out emulsification stirring at a rotation speed of 1200 r / min. Slowly drop the oil phase into the aqueous phase to prepare microcapsules encapsulating the repair agent. A2. Add the bisphenol A-bisphenol F type mixed epoxy resin to a three-necked flask equipped with a stirrer, a thermometer and a condenser, slowly heat it to 90 °C, stir at a speed of 300 r / min, slowly and evenly add the DDS curing agent and the organic nano-montmorillonite, and continue to stir for 60 minutes after adding. A3. Control the temperature of the above system at 70 °C and the stirring speed at 200 r / min. Drop the perfluorooctanoic acid acetone solution at a rate of 3 mL per minute through a constant pressure dropping funnel. After the dropping is completed, continue to stir for 40 minutes; transfer the system to a rotary evaporator and heat it to 90 °C under a reduced pressure of 50 kPa. A4. Pour the epoxy resin system after the second modification into a three-necked flask, heat it to 75 °C, slowly add the low molecular weight polyamide while stirring at a speed of 300 r / min, and continue to stir for 60 minutes after adding; then add the surface-modified nano-SiO₂ and continue to stir for 50 minutes; when the temperature drops to 65 °C, slowly add the PTFE micro-powder and the microcapsules containing the repair agent, and continue to stir for 2 hours. Finally, transfer the mixed solution to a vacuum dryer and defoam it in a vacuum environment of -0.12 MPa for 50 minutes to obtain the modified epoxy resin.

[0028] The high-temperature resistant modifier contains the following raw materials in parts by weight: 10 parts of phenylphosphonic dichloride, 15 parts of γ-aminopropyltriethoxysilane, 3 parts of anhydrous aluminum trichloride, and 50 parts of toluene. The specific preparation method of the high-temperature resistant modifier is as follows: B1. Add toluene and anhydrous aluminum trichloride to a four-necked flask, turn on the stirrer and stir at a speed of 500 r / min. After the anhydrous aluminum trichloride is completely dissolved, add the phosphorus-containing compound phenylphosphonic dichloride to the four-necked flask at a dropping rate of 3 mL per minute. After the dropping is completed, raise the temperature of the reaction system to 90 °C and keep stirring and reacting at this temperature for 2 hours to form an active intermediate. B2. Under stirring conditions, the silicon-containing compound γ-aminopropyltriethoxysilane is added dropwise through a dropping funnel at a rate of 3 mL per minute, while maintaining the reaction temperature at 90 °C. After the addition is complete, the reaction is continued by stirring at 90 °C for 2 hours to produce a phosphorus-silicon hybrid compound; B3. After the reaction is completed, the reaction system is cooled to room temperature, and then transferred to a separatory funnel. Deionized water is added to the separatory funnel, and after shaking, it is allowed to stand for liquid separation. The lower aqueous phase is discarded, and this operation is repeated 5 times; the separated organic phase is transferred to a distillation flask, and the toluene solvent is removed by distillation using a rotary evaporator at 4 kPa to obtain a crude product. The crude product is then recrystallized with absolute ethanol, the crystals are collected after filtration, and dried in a vacuum drying oven at 60 °C for 3 hours to obtain a pure phosphorus-silicon hybrid compound, namely a high-temperature resistant modifier.

[0029] Example 3

[0030] A high-temperature resistant epoxy resin composite material, comprising the following raw materials in parts by weight: 75 parts of modified epoxy resin, 11 parts of high-temperature resistant modifier, 22 parts of curing agent, 5 parts of nano-enhancing filler, 2 parts of coupling agent, 4 parts of carbon fiber, 3 parts of nano-titanium dioxide, 7 parts of silicone rubber, 2 parts of conductive agent, 5 parts of flame retardant, 3 parts of zinc borate.

[0031] A preparation method of a high-temperature resistant epoxy resin composite material specifically comprises the following steps: S1. The carbon fiber is oxidized with a 3% nitric acid solution at 60 °C for 2 hours to enhance the surface activity, then rinsed with deionized water until neutral and dried, and the treated carbon fiber is cut into 3 mm lengths; the nano-titanium dioxide is dispersed in absolute ethanol and ultrasonically dispersed for 60 minutes to form a uniform suspension; melamine cyanurate is added to a high-speed mixer and stirred with a silane coupling agent KH–550 for 30 minutes to obtain surface-treated melamine cyanurate; S2. The modified epoxy resin is added to a reaction kettle, slowly heated to 75 °C, and the stirring speed is set at 700 r / min until the epoxy resin melts completely into a uniform liquid state. The coupling agent is added, and the stirring speed is increased to 950 r / min and stirred for 52 minutes; the pretreated carbon fiber and nano-titanium dioxide suspension are added to the reaction kettle and stirred at a high speed of 950 r / min for 50 minutes; the nano-enhancing filler is slowly added to the system and ultrasonically dispersed for 22 minutes, and then continuously stirred at a speed of 700 r / min for 40 minutes; the hollow ceramic microspheres are added to the reaction kettle and stirred for another 40 minutes; S3. Reduce the rotational speed to 400 r / min, add the high-temperature resistant modifier to the above system, stir at this rotational speed for 37 minutes, and during the stirring process, raise the temperature in the reaction kettle to 85 °C; add the silicone rubber that has been plastified at 60 °C for 30 minutes to the reaction kettle and stir for 50 minutes; then add conductive carbon black, surface-treated melamine cyanurate and zinc borate, and continue to stir for 35 minutes; add 4,4'-diaminodiphenylmethane to the system, increase the stirring speed to 650 r / min, and stir for 12 minutes; S4. Quickly inject the uniformly stirred mixed material into the mold, then place the mold in the oven, pre-cure at 100 °C for 2.5 hours, after the curing is completed, raise the oven temperature to 170 °C for post-curing for 3.5 hours. After the post-curing is completed, turn off the heating equipment, let the mold cool naturally in the oven to room temperature, take out the composite material from the mold to obtain the final high-temperature resistant epoxy resin composite product.

[0032] The modified epoxy resin contains the following raw materials in parts by weight: 55 parts of bisphenol A-bisphenol F type mixed epoxy resin YLF-1700F, 17 parts of 4,4'-diaminodiphenyl sulfone curing agent, 4 parts of nano-montmorillonite, 25 parts of toluene solution containing 10% cetyltrimethylammonium bromide, 12 parts of dicyclopentadiene, 2 parts of Grubbs catalyst, 15 parts of cyclohexane, 11 parts of isophthaloyl chloride, 3 parts of hexamethylenediamine, 3 parts of perfluorooctanoic acid acetone solution, 12 parts of low molecular weight polyamide, 3 parts of nano-SiO2, 7 parts of silane coupling agent KH-560, 2 parts of PTFE micropowder; The specific preparation steps of the modified epoxy resin are as follows: A1. Put the nano-montmorillonite into a vacuum drying oven and dry it at 110 °C for 2 hours. After the drying treatment, add the nano-montmorillonite to the toluene containing cetyltrimethylammonium bromide and perform ultrasonic dispersion for 40 minutes to complete the organic modification; put the nano-silica into a vacuum drying oven and dry it at 90 °C for 1.5 hours. After drying, add the nano-SiO2 to the ethanol solution containing the silane coupling agent KH-560 and use an ultrasonic disperser to perform ultrasonic dispersion for 50 minutes to complete the surface modification; dissolve the dicyclopentadiene and the Grubbs catalyst in cyclohexane, and at the same time dissolve the isophthaloyl chloride and hexamethylenediamine in the aqueous phase and the oil phase respectively, perform emulsification stirring at a rotational speed of 1000 r / min, and slowly drop the oil phase into the aqueous phase to prepare microcapsules encapsulating the repair agent; A2. Add the bisphenol A-bisphenol F type mixed epoxy resin to a three-necked flask equipped with a stirrer, a thermometer and a condenser, slowly heat it to 85 °C, stir at a rotational speed of 250 r / min, slowly and uniformly add the DDS curing agent and the organic nano-montmorillonite, and continue to stir for 45 minutes after adding; A3. Control the temperature of the above system at 65 °C, with a stirring speed of 150 r / min. Dropwise add the perfluorooctanoic acid acetone solution at a rate of 2 mL per minute through a constant-pressure dropping funnel. After the addition is complete, continue stirring for 30 minutes; transfer the system to a rotary evaporator and heat it to 85 °C under a reduced pressure of 45 kPa; A4. Pour the epoxy resin system after the second modification into a three-necked flask, heat it to 72 °C, and slowly add low-molecular-weight polyamide while stirring at a speed of 250 r / min. After the addition, continue stirring for 50 minutes; then add surface-modified nano-SiO2 and continuously stir for 40 minutes; when the temperature drops to 62 °C, slowly add PTFE micropowder and microcapsules containing the repair agent, and continuously stir for 1.5 hours. Finally, transfer the mixture to a vacuum dryer and defoam it for 40 minutes in a vacuum environment of -0.10 MPa to obtain the modified epoxy resin.

[0033] The high-temperature resistant modifier contains the following raw materials in parts by weight: 7 parts of dichlorophenylphosphine, 11 parts of γ-aminopropyltriethoxysilane, 2 parts of anhydrous aluminum trichloride, and 40 parts of toluene; The specific preparation method of the high-temperature resistant modifier is as follows: B1. Add toluene and anhydrous aluminum trichloride to a four-necked flask, turn on the stirrer, and stir at a speed of 400 r / min. After anhydrous aluminum trichloride is completely dissolved, add the phosphorus-containing compound dichlorophenylphosphine to the four-necked flask at a dropping rate of 2 mL per minute. After the addition is complete, raise the temperature of the reaction system to 85 °C and continue stirring and reacting at this temperature for 1.5 hours to form an active intermediate; B2. Under stirring conditions, dropwise add the silicon-containing compound γ-aminopropyltriethoxysilane at a rate of 2 mL per minute through a dropping funnel while maintaining the reaction temperature at 85 °C. After the addition is complete, continue stirring and reacting at 85 °C for 1.5 hours to generate a phosphorus-silicon hybrid compound; B3. After the reaction is completed, cool the reaction system to room temperature, then transfer it to a separating funnel, add deionized water to the separating funnel, shake it and let it stand for separation, discard the lower aqueous phase, and repeat this operation 4 times; transfer the separated organic phase to a distillation flask, and use a rotary evaporator to distill off the toluene solvent at 2.5 kPa to obtain a crude product. Then, recrystallize the crude product with anhydrous ethanol, filter and collect the crystals, and dry them in a vacuum drying oven at 55 °C for 2.5 hours to obtain a pure phosphorus-silicon hybrid compound, that is, the high-temperature resistant modifier.

[0034] Comparative Example 1 This comparative example is the same as Example 2 except that the modified epoxy resin is not added.

[0035] Comparative Example 2 This comparative example is the same as Example 2 except that the high-temperature resistant modifier is not added.

[0036] Performance test Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Thermal decomposition temperature (°C) 380 400 390 300 320 Glass transition temperature (°C) 180 200 190 150 160 Tensile strength (MPa) 80 95 88 60 70 Flexural strength (MPa) 120 140 130 90 100 Wear loss (mg) 15 12 13 25 20 Self-healing efficiency (%) 70 80 75 0 78 Gas permeability (cm³·cm / cm²·s·Pa) <![CDATA[5×10 -11 > <![CDATA[4×10 -11 > <![CDATA[4.5×10 -11 > <![CDATA[1×10 -10 > <![CDATA[4×10 -11 > Surface friction coefficient 0.12 0.10 0.11 0.20 0.10 Resistivity (S / cm) <![CDATA[1.5×10 -3 > <![CDATA[2.0×10 -3 > <![CDATA[1.8×10 -3 > <![CDATA[1.0×10 -5 > <![CDATA[1.2×10 -5 > Combustion rating V-0 V-0 V-0 V-2 V-1 Through a number of performance tests on Examples 1-3 and Comparative Examples 1-2, the results show that: the performance of each example is better than that of the comparative example. In terms of thermal performance, the thermal decomposition temperature of the examples is 380-400 °C, and the glass transition temperature is 180-200 °C, which is significantly higher than that of the comparative example. This benefits from the stable structure and barrier layer formed by the high-temperature resistant modifier and nano-montmorillonite. In terms of mechanical properties, the tensile strength of the examples is 80-95 MPa, and the flexural strength is 120-140 MPa, far exceeding that of the comparative example. The synergistic effect of nano-boron nitride, modified epoxy resin components and high-temperature resistant modifier enhances the material strength. The abrasion resistance of the examples is also better, with a mass loss of 12-15 mg. In terms of self-healing efficiency, the examples reach 70-80%, while Comparative Example 1 has no repair function. In terms of gas permeability, the examples are lower than Comparative Example 1, indicating better impermeability. The surface friction coefficient of the examples is lower than that of Comparative Example 1, indicating that its surface is smoother and the frictional resistance is smaller. Example 2 has the smallest resistivity and a combustion rating of V-0. The other two examples are inferior to Example 2, and the comparative examples are far less than Example 2. It can be seen that the epoxy resin composite material added with modified epoxy resin and high-temperature resistant modifier has better effects.

[0037] The above content is only an example and explanation of the present invention. Those skilled in the art of the present technology can make various modifications or supplements to the described specific embodiments or use similar methods to replace them. As long as they do not deviate from the invention or exceed the scope defined by the claims of the present invention, they should all fall within the protection scope of the present invention.

Claims

1. A high temperature resistant epoxy resin composite material, characterized in that: The invention comprises the following raw materials in parts by weight: 70-80 parts of modified epoxy resin, 8-15 parts of high temperature resistant modifier, 15-30 parts of curing agent, 3-8 parts of nano-reinforced filler, 1-3 parts of coupling agent, 3-6 parts of carbon fiber, 2-5 parts of nano-titanium dioxide, 5-10 parts of silicone rubber, 1-3 parts of conductive agent, 3-7 parts of flame retardant and 2-4 parts of zinc borate.

2. The high temperature resistant epoxy resin composite material according to claim 1, characterized in that: The modified epoxy resin comprises the following raw materials in parts by weight: 50-60 parts of bisphenol A-bisphenol F type mixed epoxy resin YLF-1700F, 15-20 parts of 4,4'-diaminodiphenyl sulfone curing agent, 3-5 parts of nano-montmorillonite, 20-30 parts of toluene solution containing 10% hexadecyltrimethylammonium bromide, 10-15 parts of dicyclopentadiene, 1-3 parts of Grubbs catalyst, 10-20 parts of cyclohexane, 8-15 parts of isophthaloyl chloride, 2-4 parts of hexamethylenediamine, 2-5 parts of perfluorooctanoic acid acetone solution, 10-15 parts of low molecular weight polyamide, 2-5 parts of nano-SiO2, 5-10 parts of silane coupling agent KH-560, and 1-3 parts of PTFE micropowder; The modified epoxy resin is specifically prepared in the following steps: A1. Place nano-montmorillonite in a vacuum drying oven and dry it at 100-120° C. for 1-3 hours. After drying, add the nano-montmorillonite to toluene containing hexadecyltrimethylammonium bromide and perform ultrasonic dispersion for 30-50 minutes to complete organic treatment. Place nano-silicon dioxide in a vacuum drying oven and dry it at 80-100° C. for 1-2 hours. After drying, add nano-SiO2 to an ethanol solution containing a silane coupling agent KH-560 and perform ultrasonic dispersion for 40-60 minutes using an ultrasonic disperser to complete surface modification. Dissolve dicyclopentadiene and Grubbs catalyst in cyclohexane, dissolve isophthaloyl chloride and hexamethylenediamine in the water phase and the oil phase respectively, perform emulsification and stirring at a speed of 800-1200 r / min, and slowly drop the oil phase into the water phase to prepare microcapsules encapsulating the repair agent. A2, add bisphenol A-bisphenol F type mixed epoxy resin into a three-necked flask containing a stirrer, a thermometer and a condenser, slowly heat to 80-90 ° C, stir at a speed of 200-300 r / min, slowly and evenly add DDS curing agent and organic nano-montmorillonite, and continue stirring for 30-60 minutes after adding; A3. The temperature of the above system is controlled at 60-70°C, the stirring speed is 100-200r / min, and the perfluorooctanoic acid acetone solution is added dropwise at 1-3mL per minute through a constant pressure dropping funnel. After the addition is completed, stirring is continued for 20-40 minutes; the system is transferred to a rotary evaporator and heated to 80-90°C under a reduced pressure of 40-50kPa; A4. Pour the epoxy resin system after the second modification into a three-necked flask, heat it to 70-75°C, slowly add low molecular weight polyamide while stirring at a speed of 200-300r / min, and continue stirring for 40-60 minutes after the addition; then add the surface-modified nano-SiO2, and continue stirring for 30-50 minutes; the temperature is reduced to 60-65°C, slowly add PTFE micropowder and microcapsules containing a repair agent, and continue stirring for 1-2 hours. Finally, transfer the mixed solution to a vacuum dryer, degas in a vacuum environment of -0.08MPa to -0.12MPa for 30-50 minutes to obtain a modified epoxy resin.

3. The high temperature resistant epoxy resin composite material according to claim 1, characterized in that: The high temperature resistant modifier comprises the following raw materials in parts by weight: 5-10 parts of phenylphosphonic acid dichloride, 8-15 parts of γ-aminopropyltriethoxysilane, 1-3 parts of anhydrous aluminum chloride, and 30-50 parts of toluene; The specific preparation method of the high temperature resistant modifier is as follows: B1. Add toluene and anhydrous aluminum chloride to a four-necked flask, turn on the stirrer, stir at a speed of 300-500 r / min, and after the anhydrous aluminum chloride is completely dissolved, add the phosphorus-containing compound phenylphosphonic acid dichloride to the four-necked flask at a drip rate of 1-3 mL per minute. After the dropwise addition is completed, heat the reaction system to 80-90° C. and maintain this temperature and continue stirring the reaction for 1-2 hours to form an active intermediate; B2. Under stirring conditions, add the silicon-containing compound γ-aminopropyltriethoxysilane at a rate of 1-3 mL per minute through a dropping funnel, while maintaining the reaction temperature at 80-90° C. After the addition is completed, continue to stir the reaction at 80-90° C. for 1-2 hours to generate a phosphorus-silicon hybrid compound; B3. After the reaction is completed, the reaction system is cooled to room temperature and then transferred to a separatory funnel, deionized water is added to the separatory funnel, and the mixture is allowed to stand for stratification after shaking, and the lower aqueous phase is discarded. This operation is repeated 3-5 times; the organic phase after separation is transferred to a distillation flask, and the toluene solvent is removed by distillation at 1-4 kPa using a rotary evaporator to obtain a crude product, and the crude product is recrystallized with anhydrous ethanol, and the crystals are collected after filtration, and dried in a vacuum drying oven at 50-60° C. for 2-3 hours to obtain a pure phosphorus-silicon hybrid compound, i.e., a high temperature resistant modifier.

4. The high temperature resistant epoxy resin composite material according to claim 1, characterized in that: The curing agent is one of phthalic anhydride, methyltetrahydrophthalic anhydride and 4,4'-diaminodiphenylmethane.

5. The high temperature resistant epoxy resin composite material according to claim 1, characterized in that: The nano-reinforced filler is surface-treated nano-boron nitride.

6. The high temperature resistant epoxy resin composite material according to claim 1, characterized in that: The coupling agent is an aminosilane coupling agent and a titanate coupling agent mixed in a ratio of 1:

1.

7. The high temperature resistant epoxy resin composite material according to claim 1, characterized in that: The conductive agent is one of carbon nanotubes, graphene nanosheets and conductive carbon black.

8. The high temperature resistant epoxy resin composite material according to claim 1, characterized in that: The flame retardant is one of expanded vermiculite, aluminum hydroxide and melamine cyanurate.

9. The method for preparing a high temperature resistant epoxy resin composite material according to claim 1, characterized in that: The specific steps include: S1. The carbon fiber was oxidized with a 3% nitric acid solution at 60°C for 2 hours to enhance the surface activity, then rinsed with deionized water until neutral and dried, and the treated carbon fiber was cut into 3 mm lengths; nano-titanium dioxide was dispersed in anhydrous ethanol and ultrasonically dispersed for 60 minutes to form a uniform suspension; the flame retardant was added with silane coupling agent KH-550 in a high-speed mixer and stirred for 30 minutes to obtain a surface-treated flame retardant; S2. Add the modified epoxy resin into the reaction kettle, slowly raise the temperature to 70-80°C, set the stirring speed to 600-800r / min, until the epoxy resin is completely melted and becomes a uniform liquid, add the coupling agent, increase the stirring speed to 900-1000r / min, and stir for 45-60 minutes; Add the pretreated carbon fiber and nano-titanium dioxide suspension into the reactor and stir at a high speed of 900-1000r / min for 40-60 minutes; slowly add the nano-reinforced filler into the system, ultrasonically disperse for 15-30 minutes, and then continue stirring at a speed of 600-800r / min for 30-50 minutes; add the hollow ceramic microspheres into the reactor and continue stirring for 30-50 minutes; S3, reduce the speed to 300-500r / min, add the high temperature resistant modifier to the above system, maintain the speed and stir for 30-45 minutes, during the stirring process, increase the temperature in the reactor to 80-90°C; add the silicone rubber after plasticizing at 60°C for 30 minutes to the reactor, stir for 40-60 minutes; then add the conductive agent, the surface treated flame retardant and zinc borate, and continue stirring for 30-40 minutes; add the curing agent to the system, increase the stirring speed to 500-800r / min, and stir for 10-15 minutes; S4. Quickly inject the evenly stirred mixture into the mold, then put the mold into an oven, pre-cure it at 90-110°C for 2-3 hours, and after curing, increase the oven temperature to 160-180°C and post-cure it for 3-4 hours. After post-curing, turn off the heating equipment, let the mold cool naturally to room temperature in the oven, take the composite material out of the mold, and obtain the final high temperature resistant epoxy resin composite material product.