High-temperature-resistant cyanate ester resin for carbon fiber composite core and preparation method of high-temperature-resistant cyanate ester resin

Abstract

The invention relates to the technical field of high polymer material preparation, in particular to high-temperature-resistant cyanate ester resin for a carbon fiber composite core and a preparation method of the high-temperature-resistant cyanate ester resin. The high-temperature-resistant cyanate resin for the carbon fiber composite core is prepared from the following raw materials in parts by weight: 45 to 60 parts of bisphenol A dicyanate, 25 to 35 parts of bisphenol E dicyanate, 4 to 8 parts of nano aluminum nitride, 8 to 10 parts of modified polyether-ether-ketone microspheres, 5 to 10 parts of tri (4-cyanophenyl) borate and 2 to 5 parts of molybdenum disulfide nanosheets. The tri (4-cyanophenyl) borate is prepared from the following raw materials: trimethyl borate, p-hydroxybenzonitrile and potassium carbonate; according to the modified polyether-ether-ketone microspheres, chitosan and gamma-methacryloxy propyl trimethoxy silane are adopted as a modifying agent. The carbon fiber composite core prepared from the high-temperature-resistant cyanate ester resin prepared by the invention has excellent high-temperature resistance and aging resistance.

Description

Technical Field

[0001] The present invention relates to the technical field of polymer material preparation, and particularly relates to a high-temperature resistant cyanate ester resin for carbon fiber composite cores and a preparation method thereof. Background Art

[0002] The carbon fiber composite core wire is a new type of wire. Due to its small dielectric loss, it is more suitable for electromagnetic signal sensitive fields or extreme environments such as components near aeroengines and deep-sea exploration equipment. It was mainly used in aerospace equipment and space stations, and now it is mostly used as an overhead transmission line wire. The carbon fiber composite core wire has a single core rod made of a carbon fiber composite core coated with glass fiber as the central layer and trapezoidal cross-section aluminum stranded wire strands as the outer layer. Compared with traditional steel core aluminum stranded wires, the carbon fiber composite core wire has a small load and has significant low sag characteristics, making it suitable for capacity increase and transformation projects.

[0003] The technology of carbon fiber composite core wires currently still has the following technical problems: First, when operating at high temperatures for a long time, the core rod resin in the wire is prone to aging and even brittle fracture; second, the high-temperature resistance of the carbon fiber composite core is not ideal, and the instantaneous working temperature generally does not exceed 300°C. After retrieval, the prior art with the publication number CN103819898A discloses a carbon fiber composite core, whose long-term working temperature can be increased to above 260°C and the instantaneous working temperature can reach 290°C, but its aging resistance is poor; the prior art with the publication number CN112151206A discloses a carbon fiber composite core wire, whose carbon fiber composite wire core has a relatively high tensile strength, but the problem of poor high-temperature resistance has not been solved.

[0004] In summary, the existing resins for carbon fiber composite cores have problems of easy aging and insufficient high-temperature resistance. Summary of the Invention

[0005] Aiming at the above technical problems, the purpose of the present invention is to provide a high-temperature resistant cyanate ester resin for carbon fiber composite cores and a preparation method thereof to improve the high-temperature resistance and aging resistance of the resin for carbon fiber composite cores.

[0006] To achieve the above purpose, the following technical solutions are adopted: A high-temperature resistant cyanate ester resin for carbon fiber composite cores, the raw materials of which include: bisphenol A dicyanate, bisphenol E dicyanate, nano-aluminum nitride, modified polyether ether ketone microspheres, tris(4-cyanophenyl) borate, and molybdenum disulfide nanosheets.

[0007] The weight ratio of the above raw materials is: 45 - 60 parts of bisphenol A dicyanate, 25 - 35 parts of bisphenol E dicyanate, 4 - 8 parts of nano-aluminum nitride, 8 - 10 parts of modified polyether ether ketone microspheres, 5 - 10 parts of tris(4-cyanophenyl) borate, and 2 - 5 parts of molybdenum disulfide nanosheets.

[0008] A preparation method of a high-temperature resistant cyanate ester resin for a carbon fiber composite core, comprising steps of preparing modified polyetheretherketone microspheres, preparing tris(4-cyanophenyl) borate, and synthesizing the cyanate ester resin.

[0009] For the preparation of the modified polyetheretherketone microspheres, based on parts by weight, the raw materials include: 10 - 15 parts of polyetheretherketone microspheres, 0.5 - 1 part of γ-methacryloxypropyltrimethoxysilane, 2 - 5 parts of chitosan, 1 - 2 parts of glacial acetic acid, and 60 - 100 parts of deionized water.

[0010] Furthermore, for the polyetheretherketone microspheres, the molecular weight distribution (PDI) < 2.0, and the particle size is 50 - 100 μm; for the chitosan, the degree of deacetylation (DD) is 50 - 80%, and the molecular weight distribution (PDI) < 1.5.

[0011] The preparation of the modified polyetheretherketone microspheres: Pickle the polyetheretherketone microspheres, put the pickled polyetheretherketone microspheres, γ-methacryloxypropyltrimethoxysilane, and deionized water into a reactor, and stir and react at 80 - 90 °C for 1 - 2 h; after the reaction ends, cool down to 50 - 60 °C, then put glacial acetic acid and chitosan into the reactor, and continue to stir and react for 2 - 3 h; after the reaction ends, filter the materials in the reactor, retain the solid, and obtain the modified polyetheretherketone microspheres.

[0012] Furthermore, for the pickling: Use a 3wt% H2SO4 solution to stir and soak the polyetheretherketone microspheres for 20 - 30 min.

[0013] The preparation of tris(4-cyanophenyl) borate: First, add trimethyl borate and p-hydroxybenzonitrile to dimethyl sulfoxide for pre-reaction, then add potassium carbonate and heat up to 140 - 160 °C, and react for 12 - 18 h to obtain a reaction solution; extract the reaction solution to obtain an organic phase; then perform atmospheric distillation and vacuum distillation on the organic phase, and the obtained solid is tris(4-cyanophenyl) borate.

[0014] The molar ratio of trimethyl borate, p-hydroxybenzonitrile, and potassium carbonate is 1:(3.1 - 3.4):(2 - 3).

[0015] Furthermore, for the pre-reaction, the pre-reaction temperature is 120 - 130 °C, and the pre-reaction time is 6 - 8 h.

[0016] Furthermore, for the dimethyl sulfoxide, the dosage is 20 - 25 times the volume of trimethyl borate.

[0017] Further, for the extraction: Add ice water at 0 - 5°C into the reaction solution. The amount of ice water used is 100 times the volume of trimethyl borate, and stir for 30 min. Then add dichloromethane. The amount of dichloromethane used is 50 times the volume of trimethyl borate, stir for 1 h, let it stand for liquid separation, and retain the lower organic phase.

[0018] Further, for the atmospheric distillation: The temperature is 60 - 65°C.

[0019] Further, for the vacuum distillation: The temperature is 35 - 40°C, and the pressure < -0.080 MPa.

[0020] For the synthesis of the cyanate ester resin, by weight, the raw materials include: 45 - 60 parts of bisphenol A dicyanate, 20 - 35 parts of bisphenol E dicyanate, 4 - 8 parts of nano aluminum nitride, 8 - 10 parts of modified polyetheretherketone microspheres, 5 - 10 parts of tris(4 - cyanophenyl) borate, and 2 - 5 parts of molybdenum disulfide nanosheets.

[0021] Further, for the nano aluminum nitride, the particle size is 50 - 200 nm; for the molybdenum disulfide nanosheets, the diameter is 2 - 10 μm, and the thickness is 10 - 30 nm.

[0022] For the synthesis of the cyanate ester resin: First, add bisphenol A dicyanate and bisphenol E dicyanate into the reactor and heat to 90°C, and maintain for 10 - 20 min. Then add nano aluminum nitride, modified polyetheretherketone microspheres, tris(4 - cyanophenyl) borate, and molybdenum disulfide nanosheets, and obtain the high - temperature - resistant cyanate ester resin through two - step temperature - rising reactions.

[0023] Further, for the two - step temperature - rising reaction: First, raise the temperature to 130°C at a rate of 7 - 10°C / min for the first - step reaction, and the reaction time is 2 - 3 h; then raise the temperature to 170°C at a rate of 4 - 8°C / min for the second - step reaction, and the reaction time is 3 - 4 h.

[0024] The beneficial effects of the present invention are as follows: (1) The carbon fiber composite core made of the high - temperature - resistant cyanate ester resin prepared by the present invention has excellent high - temperature resistance, with a heat distortion temperature > 360°C and a glass transition temperature > 320°C.

[0025] (2) The carbon fiber composite core made of the high - temperature - resistant cyanate ester resin prepared by the present invention has good mechanical properties. The tensile strength reaches 2683 - 2711 MPa, and the interlaminar shear strength reaches 93 - 101 MPa.

[0026] (3) After 1000 h of xenon lamp aging treatment, the attenuation amplitude of the tensile strength performance of the carbon fiber composite core made of the high - temperature - resistant cyanate ester resin prepared by the present invention is < 2%, and the attenuation amplitude of the glass transition temperature is < 3.5%, showing good aging resistance. Detailed Embodiments

[0027] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be further described in detail below. It should be understood that the specific embodiments described herein are only for explaining and illustrating the present invention, and are not used to limit the present invention.

[0028] Example 1 A High-Temperature Resistant Cyanate Ester Resin for Carbon Fiber Composite Core Step 1: Prepare modified polyether ether ketone microspheres By weight, the raw materials include: 12 parts of polyether ether ketone microspheres, 1 part of γ-methacryloxypropyltrimethoxysilane, 2.5 parts of chitosan, 1.5 parts of glacial acetic acid, and 70 parts of deionized water.

[0029] Pickle the polyether ether ketone microspheres with 3wt% H2SO4 solution, take them out after stirring and leaching for 30 min; put the pickled polyether ether ketone microspheres, γ-methacryloxypropyltrimethoxysilane, and deionized water into a reactor, and stir and react at 90 °C for 1 h; after the reaction is completed, cool down to 60 °C, then put glacial acetic acid and chitosan into the reactor, and continue to stir and react for 2 h. After the reaction is completed, filter the materials in the reactor, retain the solid to obtain modified polyether ether ketone microspheres. After the modified polyether ether ketone microspheres are washed with water, they are vacuum dried at 60 °C for 24 h and reserved for use.

[0030] The polyether ether ketone microspheres used in this step: molecular weight distribution (PDI) < 2.0, particle size 50 - 100 μm; chitosan: deacetylation degree (DD) is 50 - 80%, molecular weight distribution (PDI) < 1.5.

[0031] Step 2: Prepare tris(4-cyanophenyl) borate The raw materials include: trimethyl borate, p-hydroxybenzonitrile, and potassium carbonate. The molar ratio of trimethyl borate, p-hydroxybenzonitrile, and potassium carbonate is 1:3.2:2.5.

[0032] Add trimethyl borate and p-hydroxybenzonitrile to dimethyl sulfoxide, protect with nitrogen, and stir and react at 120 °C for 8 h; then add potassium carbonate, raise the temperature to 160 °C, and continue to stir and react for 12 h to obtain a reaction solution; add ice water to the reaction solution and stir for 30 min; then add dichloromethane to extract tris(4-cyanophenyl) borate, continue to stir for 1 h, let it stand until it layers, and retain the lower organic phase; repeat the extraction operation three times. Distill the extracted organic phase: perform atmospheric distillation at 60 °C, after the atmospheric distillation is completed, adjust the temperature to 40 °C and the pressure < -0.080 MPa, and continue to perform vacuum distillation on the organic phase. After distillation is completed, obtain tris(4-cyanophenyl) borate solid.

[0033] In this step, the dosage of dimethyl sulfoxide is 20 times the volume of trimethyl borate; the temperature range of the ice water used is 0 - 5°C, and the dosage of ice water is 100 times the volume of trimethyl borate; the dosage of dichloromethane is 50 times the volume of trimethyl borate.

[0034] Step 3. Synthesis of cyanate ester resin By weight, the raw materials include: 45 parts of bisphenol A dicyanate, 35 parts of bisphenol E dicyanate, 8 parts of nano aluminum nitride, 9 parts of modified polyetheretherketone microspheres, 7 parts of tris(4-cyanophenyl) borate, and 5 parts of molybdenum disulfide nanosheets.

[0035] First, add bisphenol A dicyanate and bisphenol E dicyanate into the reactor, heat up to 90°C, and stir for 10 min. Then put nano aluminum nitride, modified polyetheretherketone microspheres, tris(4-cyanophenyl) borate, and molybdenum disulfide nanosheets into the reactor, and then heat up to 130°C at a rate of 7°C / min and stir and react for 2 h. Then heat up to 170°C at a rate of 8°C / min and stir and react for 4 h. After the reaction ends, a high-temperature resistant cyanate ester resin is obtained.

[0036] In this step, the molybdenum disulfide nanosheets used: diameter 2 - 10 μm, thickness 10 - 30 nm; nano aluminum nitride: particle size 50 - 200 nm.

[0037] Example 2 A high-temperature resistant cyanate ester resin for carbon fiber composite core Step 1. Preparation of modified polyetheretherketone microspheres By weight, the raw materials include: 15 parts of polyetheretherketone microspheres, 1 part of γ-methacryloxypropyltrimethoxysilane, 5 parts of chitosan, 2 parts of glacial acetic acid, and 100 parts of deionized water.

[0038] Use 3wt% H2SO4 solution to pickle the polyetheretherketone microspheres, take them out after stirring and pickling for 30 min; put the pickled polyetheretherketone microspheres, γ-methacryloxypropyltrimethoxysilane, and deionized water into the reactor, and stir and react at 90°C for 1 h; after the reaction ends, cool down to 50°C, then put glacial acetic acid and chitosan into the reactor and continue to stir and react for 3 h. After the reaction ends, filter the materials in the reactor, retain the solid, and obtain modified polyetheretherketone microspheres. After the modified polyetheretherketone microspheres are washed with water, they are vacuum dried at 60°C for 24 h and reserved for use.

[0039] In this step, the polyetheretherketone microspheres used: molecular weight distribution (PDI) < 2.0, particle size 50 - 100 μm; chitosan: deacetylation degree (DD) is 50 - 80%, molecular weight distribution (PDI) < 1.5.

[0040] Step 2. Preparation of tris(4-cyanophenyl) borate The raw materials include: trimethyl borate, 4-hydroxybenzonitrile, and potassium carbonate. The molar ratio of trimethyl borate, 4-hydroxybenzonitrile, and potassium carbonate is 1:3.4:3.

[0041] Add trimethyl borate and 4-hydroxybenzonitrile into dimethyl sulfoxide, introduce nitrogen for protection, and stir and react at 130 °C for 6 h; then add potassium carbonate, raise the temperature to 140 °C, and continue to stir and react for 18 h to obtain a reaction solution; add ice water to the reaction solution and stir for 30 min; then add dichloromethane to extract tris(4-cyanophenyl) borate, continue to stir for 1 h, and let it stand until it is layered, then retain the lower organic phase; repeat the extraction operation three times. Distill the extracted organic phase: perform atmospheric distillation at 65 °C, and after the atmospheric distillation is completed, adjust the temperature to 40 °C and the pressure < -0.080 MPa and continue to perform vacuum distillation on the organic phase; after the distillation is completed, obtain tris(4-cyanophenyl) borate solid.

[0042] In this step, the dosage of dimethyl sulfoxide is 25 times the volume of trimethyl borate; the temperature range of the ice water used is 0 - 5 °C, and the dosage of ice water is 100 times the volume of trimethyl borate; the dosage of dichloromethane is 50 times the volume of trimethyl borate.

[0043] Step Three: Synthesize cyanate ester resin Based on weight parts, the raw materials include: 60 parts of bisphenol A dicyanate, 20 parts of bisphenol E dicyanate, 4 parts of nano aluminum nitride, 10 parts of modified polyetheretherketone microspheres, 10 parts of tris(4-cyanophenyl) borate, and 2 parts of molybdenum disulfide nanosheets.

[0044] First, add bisphenol A dicyanate and bisphenol E dicyanate into a reactor, raise the temperature to 90 °C, and stir for 10 min. Then put nano aluminum nitride, modified polyetheretherketone microspheres, tris(4-cyanophenyl) borate, and molybdenum disulfide nanosheets into the reactor, and then raise the temperature to 130 °C at a rate of 10 °C / min and stir and react for 3 h. Then raise the temperature to 170 °C at a rate of 4 °C / min and stir and react for 3 h. After the reaction is completed, obtain a high-temperature resistant cyanate ester resin.

[0045] In this step, the molybdenum disulfide nanosheets used: the diameter is 2 - 10 μm, and the thickness is 10 - 30 nm; the nano aluminum nitride: the particle size is 50 - 200 nm.

[0046] Example 3 A high-temperature resistant cyanate ester resin for carbon fiber composite core Step One: Prepare modified polyetheretherketone microspheres Based on weight parts, the raw materials include: 10 parts of polyetheretherketone microspheres, 0.5 part of γ-methacryloxypropyltrimethoxysilane, 2 parts of chitosan, 1 part of glacial acetic acid, and 60 parts of deionized water.

[0047] The polyetheretherketone microspheres were pickled with 3 wt% H2SO4 solution, taken out after stirring and soaking for 30 min; the pickled polyetheretherketone microspheres, γ-methacryloxypropyltrimethoxysilane, and deionized water were put into a reactor, and stirred and reacted at 80 °C for 2 h; after the reaction was completed, the temperature was lowered to 55 °C, and then glacial acetic acid and chitosan were put into the reactor, and the stirring reaction was continued for 2 h. After the reaction was completed, the materials in the reactor were filtered, and the solid was retained to obtain modified polyetheretherketone microspheres. The modified polyetheretherketone microspheres were washed with water and vacuum dried at 60 °C for 24 h for standby.

[0048] The polyetheretherketone microspheres used in this step: molecular weight distribution (PDI) < 2.0, particle size 50 - 100 μm; chitosan: degree of deacetylation (DD) is 50 - 80%, molecular weight distribution (PDI) < 1.5.

[0049] Step 2: Prepare tris(4-cyanophenyl) borate The raw materials include: trimethyl borate, p-hydroxybenzonitrile, and potassium carbonate. The molar ratio of trimethyl borate, p-hydroxybenzonitrile, and potassium carbonate is 1:3.1:2.

[0050] Trimethyl borate and p-hydroxybenzonitrile were added to dimethyl sulfoxide, protected by nitrogen, and stirred and reacted at 125 °C for 7 h; then potassium carbonate was added, the temperature was raised to 150 °C, and the stirring reaction was continued for 15 h to obtain a reaction solution; ice water was added to the reaction solution and stirred for 30 min; then dichloromethane was added to extract tris(4-cyanophenyl) borate, and the stirring was continued for 1 h. After standing until layering, the lower organic phase was retained; the extraction operation was repeated three times. The obtained organic phase was distilled: atmospheric distillation was carried out at 65 °C. After the atmospheric distillation was completed, the temperature was adjusted to 35 °C and the pressure < -0.080 MPa, and the organic phase was continued to be distilled under reduced pressure. After distillation, tris(4-cyanophenyl) borate solid was obtained.

[0051] In this step, the dosage of dimethyl sulfoxide is 20 times the volume of trimethyl borate; the temperature range of the ice water used is 0 - 5 °C, and the dosage of ice water is 100 times the volume of trimethyl borate; the dosage of dichloromethane is 50 times the volume of trimethyl borate.

[0052] Step 3: Synthesize cyanate ester resin By weight, the raw materials include: 50 parts of bisphenol A dicyanate, 35 parts of bisphenol E dicyanate, 5 parts of nano-aluminum nitride, 8 parts of modified polyetheretherketone microspheres, 5 parts of tris(4-cyanophenyl) borate, and 3 parts of molybdenum disulfide nanosheets.

[0053] First, bisphenol A dicyanate and bisphenol E dicyanate are added to a reactor, and the temperature is raised to 90 °C, followed by stirring for 20 min. Then, nano-aluminum nitride, modified polyetheretherketone microspheres, tris(4-cyanophenyl) borate, and molybdenum disulfide nanosheets are added to the reactor. Subsequently, the temperature is raised to 130 °C at a rate of 9 °C / min and stirred for 3 h. Then, the temperature is raised to 170 °C at a rate of 6 °C / min and stirred for 3 h. After the reaction is completed, a high-temperature resistant cyanate ester resin is obtained.

[0054] The molybdenum disulfide nanosheets used in this step have a diameter of 2 - 10 μm and a thickness of 10 - 30 nm; the nano-aluminum nitride has a particle size of 50 - 200 nm.

[0055] Comparative Example 1 A cyanate ester resin for carbon fiber composite core Step 1: Synthesize cyanate ester resin By weight, the raw materials include: 50 parts of bisphenol A dicyanate, 35 parts of bisphenol E dicyanate, 6 parts of nano-aluminum nitride, and 3 parts of molybdenum disulfide nanosheets.

[0056] First, bisphenol A dicyanate and bisphenol E dicyanate are added to a reactor, and the temperature is raised to 90 °C, followed by stirring for 10 min. Then, nano-aluminum nitride and molybdenum disulfide nanosheets are added to the reactor. Subsequently, the temperature is raised to 130 °C at a rate of 10 °C / min and stirred for 3 h. Then, the temperature is raised to 170 °C at a rate of 4 °C / min and stirred for 3 h. After the reaction is completed, a cyanate ester resin is obtained.

[0057] The molybdenum disulfide nanosheets used in this comparative example have a diameter of 2 - 10 μm and a thickness of 10 - 30 nm; the nano-aluminum nitride used has a particle size of 50 - 200 nm.

[0058] Example 4 Application of a high-temperature resistant cyanate ester resin for carbon fiber composite core Trihydroxypropane glycidyl ether is added to the cyanate ester resin, and the mass ratio of the cyanate ester resin to trihydroxypropane glycidyl ether is 50:9. After sufficient stirring, a uniform glue solution is formed.

[0059] The T700 - 24K carbon fiber bundle is impregnated in the glue solution, and the carbon fiber bundle is pulled through a pultrusion machine. The pultrusion speed is controlled at 1 m / min, and it is dried with hot air at 100 °C for preliminary curing to obtain a prepreg.

[0060] The prepreg is laminated using an 8-layer lamination design, and the interlayer angle is controlled at ±15°; after lamination, it is transferred to a autoclave for curing to obtain a carbon fiber composite core.

[0061] Performance Test (I) The carbon fiber composite cores prepared from the resins of Examples 1 to 3 and Comparative Example 1 were respectively prepared according to the method of Example 4, and performance tests were carried out. The test results are shown in Table 1.

[0062] Performance test method: Tensile strength and elongation at break test: The carbon fiber composite core was processed into a standard specimen with a length of 700 mm and a diameter of 10 mm, placed in the test environment for 24 h, and tested according to the standard of GB / T 29324-2024.

[0063] Interlaminar shear strength test: The carbon fiber composite core was processed into a standard specimen with a length of 17 mm, a width of 15 mm, and a thickness of 4 mm, placed in the test environment for 24 h, and tested according to the standard of GB / T 1450.1-2005.

[0064] Heat distortion temperature test: The carbon fiber composite core was processed into a standard specimen with a length of 127 mm, a width of 13 mm, and a thickness of 10 mm, placed at 23 ± 2°C and 50 ± 5% relative humidity for 40 h, and tested according to the standard of ASTM D648-21.

[0065] Glass transition temperature test: The carbon fiber composite core was processed into a standard specimen with a length of 60 mm, a width of 10 mm, and a thickness of 2 mm, placed in the test environment for 24 h, and tested according to the standard of GB / T 40396-2021.

[0066] Table 1

[0067] The carbon fiber composite core made of the high-temperature resistant cyanate ester resin prepared by the present invention has an elongation at break of 3.2 - 3.5%, a tensile strength of 2683 - 2711 MPa, an interlaminar shear strength of 93 - 101 MPa, a heat distortion temperature > 360°C, and a glass transition temperature > 320°C, indicating that it has good mechanical properties and high-temperature resistance.

[0068] Performance test (II) The carbon fiber composite cores prepared from the resins of Examples 1 to 3 and Comparative Example 1 were respectively prepared according to the method of Example 4 and subjected to light aging treatment.

[0069] The parameters of the xenon lamp aging chamber for light aging treatment are as follows: irradiation intensity: 0.65 W / m² @ 340 nm, chamber temperature: 80°C ± 2°C, relative humidity: 70% ± 10%, irradiation time: 1000 h.

[0070] After the irradiation, the carbon fiber composite core was subjected to performance tests. The test results are shown in Table 2.

[0071] Table 2

[0072] The carbon fiber composite core made of the high-temperature resistant cyanate ester resin prepared by the present invention, after being subjected to 1000 h of light aging treatment, the attenuation amplitude of the tensile strength performance is <2% compared with that before the aging treatment, reaching 2675 - 2702 MPa, and the attenuation amplitude of the glass transition temperature is <3.5% compared with that before the aging treatment, reaching 314 - 319 °C.

[0073] It can be seen from the above test results that after the aging treatment, its mechanical properties and glass transition temperature have a small attenuation, indicating that the carbon fiber composite core made of the high-temperature resistant cyanate ester resin prepared by the present invention has excellent high-temperature resistance and aging resistance.

[0074] Obviously, there are many specific implementation methods that can be changed under the concept of the present invention. It should be stated here that any changes made under the inventive concept of the present invention will fall within the protection scope of the present invention.

Claims

1. A high-temperature resistant cyanate ester resin for carbon fiber composite core, characterized in that: The raw materials include: Bisphenol A dicyanate, bisphenol E dicyanate, nano aluminum nitride, modified polyetheretherketone microspheres, tris(4-cyanophenyl) borate, molybdenum disulfide nanosheets; The weight ratio of the above raw materials: bisphenol A dicyanate 45 - 60 parts, bisphenol E dicyanate 25 - 35 parts, nano aluminum nitride 4 - 8 parts, modified polyetheretherketone microspheres 8 - 10 parts, tris(4-cyanophenyl) borate 5 - 10 parts, molybdenum disulfide nanosheets 2 - 5 parts; The modified polyetheretherketone microspheres: using chitosan and γ-methacryloxypropyltrimethoxysilane as modifiers; The tris(4-cyanophenyl) borate is made from the following raw materials: trimethyl borate, p-hydroxybenzonitrile, potassium carbonate.

2. The high-temperature resistant cyanate ester resin for carbon fiber composite core according to claim 1, wherein: The modified polyetheretherketone microspheres, by weight, the raw materials include: polyetheretherketone microspheres 10 - 15 parts, γ-methacryloxypropyltrimethoxysilane 0.5 - 1 part, chitosan 2 - 5 parts, glacial acetic acid 1 - 2 parts, deionized water 60 - 100 parts.

3. The high-temperature resistant cyanate ester resin for carbon fiber composite core according to claim 1, characterized in that: The molar ratio of the raw materials of the tris(4-cyanophenyl) borate is trimethyl borate: p-hydroxybenzonitrile: potassium carbonate = 1:(3.1 - 3.4):(2 - 3).

4. The preparation method of a high-temperature resistant cyanate ester resin for a carbon fiber composite core according to claim 1, characterized in that: It includes steps of preparing modified polyetheretherketone microspheres, preparing tris(4-cyanophenyl) borate, and synthesizing cyanate resin.

5. The preparation method of a high-temperature resistant cyanate ester resin for a carbon fiber composite core according to claim 4, characterized in that: The preparation of the modified polyetheretherketone microspheres: pickling the polyetheretherketone microspheres, putting the pickled polyetheretherketone microspheres, γ-methacryloxypropyltrimethoxysilane and deionized water into a reactor, and stirring and reacting at 80 - 90 °C for 1 - 2 h; after the reaction ends, cooling to 50 - 60 °C, then putting glacial acetic acid and chitosan into the reactor and continuing to stir and react for 2 - 3 h; after the reaction ends, filtering the materials in the reactor and retaining the solid to obtain the modified polyetheretherketone microspheres.

6. The preparation method of a high-temperature resistant cyanate ester resin for a carbon fiber composite core according to claim 5, wherein: The pickling: using 3wt% H2SO4 solution to stir and soak the polyetheretherketone microspheres for 20 - 30 min.

7. The preparation method of a high-temperature resistant cyanate ester resin for a carbon fiber composite core according to claim 4, characterized in that: The preparation of the tris(4-cyanophenyl) borate: first adding trimethyl borate and p-hydroxybenzonitrile into dimethyl sulfoxide for pre-reaction, then adding potassium carbonate, heating to 140 - 160 °C and reacting for 12 - 18 h to obtain a reaction solution; extracting the reaction solution to obtain an organic phase; then performing atmospheric distillation and vacuum distillation on the organic phase, and the obtained solid is tris(4-cyanophenyl) borate.

8. The preparation method of a high-temperature resistant cyanate ester resin for a carbon fiber composite core according to claim 7, characterized in that: For the pre-reaction, the pre-reaction temperature is 120 - 130 °C and the pre-reaction time is 6 - 8 h.

9. The preparation method of a high-temperature resistant cyanate ester resin for a carbon fiber composite core according to claim 4, characterized in that: The synthesis of the cyanate resin: first adding bisphenol A dicyanate and bisphenol E dicyanate into a reactor and heating to 90 °C, maintaining for 10 - 20 min; then putting in nano aluminum nitride, modified polyetheretherketone microspheres, tris(4-cyanophenyl) borate, molybdenum disulfide nanosheets, and through two-step temperature-raising reaction, obtaining a high-temperature resistant cyanate resin.

10. The preparation method of a high-temperature resistant cyanate ester resin for a carbon fiber composite core according to claim 9, characterized in that: The two-step temperature-raising reaction: first heating at a rate of 7 - 10 °C / min to 130 °C for the first-step reaction, and the reaction time is 2 - 3 h; then heating at a rate of 4 - 8 °C / min to 170 °C for the second-step reaction, and the reaction time is 3 - 4 h.

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