Ultralow-temperature-resistant PAEK composite material and preparation method thereof

Abstract

The invention relates to the technical field of polyaryletherketone material modification, in particular to an ultralow-temperature-resistant PAEK composite material and a preparation method thereof.The ultralow-temperature-resistant PAEK composite material is prepared from PAEK resin, polyethersulfone resin, aramid fibers subjected to surface carboxylation pretreatment, flaky heat conduction filler with the heat conductivity coefficient being at least 400 W / m.K and a coupling agent; according to the invention, through the blending modification of the flaky heat-conducting filler in cooperation with the polyether sulfone (PES) microspheres and the aramid fibers, the composite material has the advantages of high strength, high toughness and low thermal stress in an extremely low-temperature environment.

Description

Technical Field

[0001] The present invention relates to the technical field of polyaryletherketone (PAEK) material modification, and in particular to an ultra-low temperature resistant PAEK composite material and a preparation method thereof. Background Art

[0002] Polyaryletherketones (PEEKs) are a class of crystalline polymers composed of phenylene rings connected by oxygen bridges (ether bonds) and carbonyl groups (ketones). Depending on the order and ratio of ether bonds, ketone groups, and benzene rings in the molecular chain, they are primarily classified as follows: polyetheretherketone (PEEK), polyetherketone (PEK), polyetherketoneketone (PEKK), polyetheretherketoneketone (PEEKK), and polyetherketoneetherketoneketone (PEKEKK). The rigidity of the benzene rings in the molecular structure of polyaryletherketones gives them excellent high-temperature performance, mechanical properties, electrical insulation, radiation resistance, and chemical corrosion resistance. The ether bonds in their molecular structure impart flexibility. Within the polyaryletherketone family, the lower the ether bond to ketone group ratio (E / K) in the molecular chain, the higher the melting point and glass transition temperature. Polyetheretherketone (PEEK), a semi-crystalline specialty engineering plastic, is widely used in aerospace, medical devices, energy equipment, and other fields. However, with the rapid development of extreme low-temperature scenarios such as liquid hydrogen (-253°C) and liquid nitrogen (-196°C) (such as commercial rocket liquid oxygen / liquid hydrogen tanks and superconducting magnet cryogenic support systems), the limitations caused by the low-temperature brittleness of traditional PAEK materials have gradually been exposed.

[0003] Fillers are often used for modification in the existing technology, but improving the low-temperature performance of PAEK by adding fillers such as fibers or particles has significant defects: glass fiber (GF) modification, the large difference in the interfacial thermal expansion coefficient between GF and PEEK leads to low-temperature thermal stress concentration; although carbon fiber (CF) modification can increase the modulus, the high modulus leads to low stress transfer efficiency at low temperatures, and the conductivity of CF is not suitable for insulation scenarios; the addition of traditional toughening agents (such as PTFE) leads to a decrease in the creep resistance of the material, which cannot meet long-term pressure requirements. Summary of the Invention

[0004] To address the aforementioned technical issues, a cryogenically resistant PAEK composite material and its preparation method are provided. By modifying the composite material through the blending of phosphorus-doped hexagonal boron nitride (P-BN) with polyethersulfone (PES) microspheres and aramid fibers, the composite material exhibits high strength, high toughness, and low thermal stress in extremely low-temperature environments.

[0005] In order to achieve the above objectives, the present invention is implemented through the following technical solutions:

[0006] A super-low temperature resistant PAEK composite material, comprising 100% by weight of the following materials:

[0007] PAEK resin 60%-75%,

[0008] Polyethersulfone resin 5%-10%,

[0009] 10%-20% of aramid fiber pretreated with surface carboxylation,

[0010] 5%-10% of sheet-like thermal conductive filler with a thermal conductivity of at least 400W / m·K,

[0011] Coupling agent 0.5%-1%.

[0012] Furthermore, the flaky thermally conductive filler is selected from phosphorus-doped hexagonal boron nitride, with a phosphorus content of 3wt%-5wt%, a flake thickness of 20-50nm, and an aspect ratio of at least 300. A phosphorus content of less than 3wt% results in insufficient P-N bond density and limited impact resistance improvement. A phosphorus content of more than 5wt% destroys the BN layered structure, reducing thermal conductivity and accelerating interface aging due to oxidation of free phosphorus. A phosphorus content of 3wt%-5wt% is the optimal window for low-temperature modified PAEK, maximizing low-temperature toughening, enhanced thermal conductivity, and interface strengthening while maintaining P-BN structural stability. Method for obtaining phosphorus-doped hexagonal boron nitride: Boron phosphate (BPO4) is used as a solid-phase boron and phosphorus source, the temperature is raised to 1000-1100°C under an inert gas protective atmosphere and the reaction is kept warm for 0.5-2 hours, and then a nitrogen source such as ammonia (NH3) or nitrogen (N2) is introduced, and the reaction is continued at the insulation temperature for 30-60 minutes. The product is removed, ultrasonically treated in ethanol, filtered and dried to obtain phosphorus-doped hexagonal boron nitride with a sheet thickness of about 20-50 nm and an aspect ratio of at least 300; wherein the nitrogen source flow rate is 200-500 seem, and the inert gas protective atmosphere flow rate is 800-1000 seem.

[0013] Furthermore, the PAEK resin is selected from one or more resins selected from polyetheretherketone (PEEK), polyetherketone (PEK), polyetherketoneketone (PEKK), polyetheretherketoneketone (PEEKK) and polyetherketoneetherketoneketone (PEKEKK), the resin particle size does not exceed 200 microns, and the melt index under the test conditions of 380°C and a load of 2.16 kg is 10-50 g / 10 min.

[0014] Furthermore, the particle size of the polyethersulfone resin is no more than 50 microns; the length of the aramid fiber is 100-300 microns and the diameter is 10-15 microns; and the coupling agent is selected from phosphate coupling agents.

[0015] Further, the coupling agent is selected from one or more of tetraisopropyl di(dioctylphosphite) titanate, a compound of di(2-ethylhexyl) phosphate and triethanolamine, a chelate of dioctylpyrophosphate titanate and triethanolamine, octadecyl phosphate, isopropyl tri(dioctylpyrophosphate) titanate, isopropyl tri(dioctylphosphite) titanate, bis(dioctylpyrophosphate) ethylene titanate, 2-fluoro-1,3-dimethylimidazolium chloride hexafluorophosphate, and isopropylated triphenyl phosphate.

[0016] The preparation method of the ultra-low temperature resistant PAEK composite material comprises the following steps:

[0017] S1. Preparing materials according to a formula; pre-treating a flaky thermally conductive filler having a thermal conductivity of at least 400 W / m·K and a polyethersulfone resin with a phosphate coupling agent to obtain a first material;

[0018] Introducing carboxyl groups on the surface of aramid fibers to obtain a second material;

[0019] S2. Melt-blending and extruding the PAEK resin, the first material, and the second material to obtain an ultra-low temperature resistant PAEK composite material.

[0020] Furthermore, the pretreatment step of S1 is as follows: dispersing the flaky thermal conductive filler and the polyethersulfone resin in an alcohol solvent, adding the phosphate coupling agent after ultrasonic dispersion, heating to 2-8°C below the boiling point of the alcohol solvent and continuing ultrasonic dispersion for 1-5 hours, and then drying, grinding, and sieving.

[0021] Furthermore, the surface introduction method of S1 is: first drying the aramid fiber to a moisture content of less than 0.1 wt%, and then treating it with low-temperature oxygen plasma at a power of 60-100 W and an oxygen flow rate of 5-20 sccm for 4-10 minutes.

[0022] Furthermore, S2 uses a co-rotating meshing twin-screw extruder for melt blending, the screw diameter of the twin-screw extruder is 35 mm, the aspect ratio is 40:1, the rotation speed is 250-350 rpm, and the temperature of each section of the twin-screw extruder is set as follows: feeding section 340-350 ° C, melting section 370-380 ° C, mixing section 370-380 ° C, exhaust section 345-365 ° C, homogenization section 355-365 ° C, head 340-355 ° C; wherein the second material is added from the side feeding port at a feeding rate of 3-6 kg / h (to avoid thermal damage to the fiber); wherein the exhaust section has an exhaust port connected to the vacuum system, and volatile small molecular substances such as alcohol solvents in the melt are removed by negative pressure, and the vacuum negative pressure is -0.06 MPa to -0.09 MPa.

[0023] Beneficial technical effects:

[0024] The present invention treats phosphorus-doped hexagonal boron nitride (P-BN) and polyethersulfone (PES) microspheres with a phosphate coupling agent, and then melt-blends them with surface-carboxylated aramid fibers and a PAEK matrix resin to obtain a composite material with the advantages of high strength, high toughness, and low thermal stress in extremely low-temperature environments. The composite material of the present invention is suitable for liquid hydrogen / liquid oxygen storage and transportation system components such as sealing rings and valve components, for superconducting magnet support structures with low thermal expansion and high insulation, and for polar equipment such as mechanical joints and sensor housings. DETAILED DESCRIPTION

[0025] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, rather than all embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is in no way intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0026] Unless otherwise specifically stated, the numerical value set forth in these embodiments does not limit the scope of the present invention. The technology and method known to those of ordinary skill in the relevant art may not be discussed in detail, but in appropriate circumstances, the technology and method should be considered as a part of the specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments can have different values. It should be noted that, for example, the value described as "within the range of ab", "between the range of ab" does not include endpoint values ​​a and b; the value described as "for ab", "is ab", "ab" includes endpoint values ​​a and b.

[0027] In addition, it should be noted that the use of terms such as "first" and "second" to limit materials is only for the convenience of distinguishing the substances in each step. Unless otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.

[0028] In the following examples, the experimental methods without specific conditions are generally measured according to national standards; if there is no corresponding national standard, the general standard requirements or general methods are used.

[0029] Preparation Example 1

[0030] This case is the preparation of phosphorus-doped hexagonal boron nitride:

[0031] 200 g of boron phosphate powder was placed in a crucible and heated to 1000°C at a rate of 10°C / min in an argon atmosphere of 1000 sccm. The mixture was then annealed at 1000°C for 10 minutes. Ammonia was then introduced at a rate of 500 sccm and the reaction was continued at 1000°C for 30 minutes. After the mixture was naturally cooled to room temperature, the product was removed, ultrasonically treated in ethanol, and filtered and dried to obtain phosphorus-doped hexagonal boron nitride with a sheet thickness of 20-50 nm and an aspect ratio of at least 300, which was designated P-BN-I.

[0032] 200 g of boron phosphate powder was placed in a crucible and heated to 1100°C at a rate of 10°C / min in an argon atmosphere of 900 sccm. The mixture was then annealed at 1100°C for 10 min, followed by introduction of ammonia at a rate of 300 sccm and continued to react at 1100°C for 60 min. After naturally cooling to room temperature, the product was removed, ultrasonically treated in ethanol, and filtered and dried to obtain phosphorus-doped hexagonal boron nitride with a sheet thickness of 20-50 nm and an aspect ratio of at least 300, which was designated P-BN-II.

[0033] 200 g of boron phosphate powder was placed in a crucible and heated to 1000°C at a rate of 10°C / min in an argon atmosphere of 800 sccm. The mixture was then annealed at 1000°C for 10 minutes. Ammonia was then introduced at a rate of 400 sccm and the reaction was continued at 1000°C for 45 minutes. After cooling naturally to room temperature, the product was removed, ultrasonically treated in ethanol, and filtered and dried to obtain phosphorus-doped hexagonal boron nitride with a sheet thickness of 20-50 nm and an aspect ratio of at least 300, which was designated P-BN-III.

[0034] The phosphorus content of the phosphorus-doped hexagonal boron nitride is tested to be approximately 3-5 wt %.

[0035] Example 1

[0036] A super-low temperature resistant PEEK composite material, comprising 100% by weight of the following materials:

[0037] PEEK resin (Junhua, PEEK3600UF) with a particle size of 100-200 μm, a melt index of 30 g / 10 min under the test conditions of 380°C and a load of 2.16 kg is 64%,

[0038] 8% polyethersulfone resin microspheres with a particle size of 10 μm (solvay VW-10200RSFP further ground)

[0039] Surface carboxylation treated aramid fibers (length 100-300 microns, diameter 10-15 microns) 17%,

[0040] Phosphorus doped hexagonal boron nitride flake filler (P-BN-Ⅰ) 10%,

[0041] Bis(dioctyloxypyrophosphate)ethylene titanate 1%;

[0042] The preparation method of the ultra-low temperature resistant PEEK composite material comprises the following steps:

[0043] S1. Prepare materials according to the recipe;

[0044] Phosphorus-doped hexagonal boron nitride flake filler and polyethersulfone resin microspheres were dispersed in anhydrous ethanol (solid-liquid ratio of 1 g:10 mL), and ultrasonically dispersed at a power of 600 W and a frequency of 40 kHz for 30 minutes. Then, bis(dioctyloxypyrophosphate)ethylene titanate was added, and the temperature was raised to 70° C. and ultrasonically dispersed for 2 hours. The mixture was then dried, ground, and passed through a 300-mesh sieve to obtain a first material for pretreatment.

[0045] The aramid fiber is dried to a moisture content of less than 0.1 wt %, and then treated with a low-temperature oxygen plasma at a power of 80 W and an oxygen flow rate of 10 sccm for 8 minutes (the aramid fiber is spread in a reaction chamber of the low-temperature oxygen plasma equipment with a stacking thickness of ≤3 cm, and the single batch processing volume does not exceed 15% of the effective volume of the reaction chamber) to introduce carboxyl groups on the surface of the aramid fiber to obtain a second material;

[0046] S2. PEEK resin, the first material and the second material are melt-blended and extruded using a co-rotating meshing twin-screw extruder, wherein the screw diameter of the twin-screw extruder is 35 mm, the aspect ratio is 40:1, and the rotation speed is 280 rpm. The temperature of each section of the twin-screw extruder is set as follows: 340°C for the feeding section, 370°C for the melting section, 370°C for the mixing section, 350°C for the exhaust section, 365°C for the homogenizing section, and 340°C for the die; wherein the second material is added from the side feeding port at a feeding rate of 5.0 kg / h; wherein the exhaust section has an exhaust port connected to a vacuum system, and volatile small molecular substances such as alcohol solvents in the melt are removed by negative pressure, and the vacuum negative pressure is -0.09 MPa. After extrusion, granulation is performed to obtain an ultra-low temperature resistant PEEK composite material.

[0047] Example 2

[0048] A super-low temperature resistant PEEK composite material, comprising 100% by weight of the following materials:

[0049] PEEK resin (Junhua, PEEK3600UF) with a particle size of 100-200 μm, a melt index of 30 g / 10 min under the test conditions of 380°C and a load of 2.16 kg, 70%

[0050] Polyethersulfone resin microspheres with a particle size of 10 μm (solvay VW-10200RSFP further ground) 10%,

[0051] Surface carboxyl treated aramid fibers (length 100-300 microns, diameter 10-15 microns) 12%,

[0052] Phosphorus doped hexagonal boron nitride flake filler (P-BN-Ⅱ) 7%,

[0053] Isopropyl tris(dioctyl pyrophosphate) titanate 1%;

[0054] The preparation method of the ultra-low temperature resistant PEEK composite material comprises the following steps:

[0055] S1. Prepare materials according to the recipe;

[0056] Phosphorus-doped hexagonal boron nitride flake filler and polyethersulfone resin microspheres were dispersed in anhydrous ethanol (solid-liquid ratio of 1 g:10 mL), and ultrasonically dispersed at a power of 600 W and a frequency of 40 kHz for 30 minutes. Isopropyl tri(dioctyl pyrophosphate) titanate was then added, and the temperature was raised to 70° C. and ultrasonically dispersed for 2 hours. The mixture was then dried, ground, and passed through a 300-mesh sieve to obtain a first material for pretreatment.

[0057] The aramid fiber is dried to a moisture content of less than 0.1 wt %, and then treated with low-temperature oxygen plasma at a power of 80 W and an oxygen flow rate of 10 sccm for 8 minutes to introduce carboxyl groups on the surface of the aramid fiber to obtain a second material;

[0058] S2. PEEK resin, the first material and the second material are melt-blended and extruded using a co-rotating meshing twin-screw extruder, wherein the screw diameter of the twin-screw extruder is 35 mm, the aspect ratio is 40:1, and the rotation speed is 300 rpm. The temperature of each section of the twin-screw extruder is set as follows: 340°C for the feeding section, 375°C for the melting section, 375°C for the mixing section, 355°C for the exhaust section, 365°C for the homogenizing section, and 345°C for the die; wherein the second material is added from the side feeding port at a feeding rate of 4.5 kg / h; wherein the exhaust section has an exhaust port connected to a vacuum system, and volatile small molecular substances such as alcohol solvents in the melt are removed by negative pressure, and the vacuum negative pressure is -0.09 MPa. After extrusion, granulation is performed to obtain an ultra-low temperature resistant PEEK composite material.

[0059] Example 3

[0060] A super-low temperature resistant PEEK composite material, comprising 100% by weight of the following materials:

[0061] PEEK resin (Junhua, PEEK3600UF) with a particle size of 100-200 μm, a melt index of 30 g / 10 min under the test conditions of 380°C and a load of 2.16 kg, 68%,

[0062] 7% polyethersulfone resin microspheres with a particle size of 10 μm (solvay VW-10200RSFP further ground)

[0063] Surface carboxyl treated aramid fibers (length 100-300 microns, diameter 10-15 microns) 19%,

[0064] Phosphorus doped hexagonal boron nitride flake filler (P-BN-Ⅲ) 5%,

[0065] Isopropyl tri(dioctylphosphoyl) titanate 1%;

[0066] The preparation method of the ultra-low temperature resistant PEEK composite material comprises the following steps:

[0067] S1. Prepare materials according to the recipe;

[0068] Phosphorus-doped hexagonal boron nitride flake filler and polyethersulfone resin microspheres were dispersed in anhydrous ethanol (solid-liquid ratio of 1 g:10 mL), and ultrasonically dispersed at a power of 600 W and a frequency of 40 kHz for 30 minutes. Isopropyl tri(dioctylphosphoyl) titanate was then added, and the temperature was raised to 70° C. and ultrasonically dispersed for 3 hours. The mixture was then dried, ground, and passed through a 300-mesh sieve to obtain a first material for pretreatment.

[0069] The aramid fiber is dried to a moisture content of less than 0.1 wt %, and then treated with low-temperature oxygen plasma at a power of 80 W and an oxygen flow rate of 10 sccm for 8 minutes to introduce carboxyl groups on the surface of the aramid fiber to obtain a second material;

[0070] S2. PEEK resin, the first material and the second material are melt-blended and extruded using a co-rotating meshing twin-screw extruder, wherein the screw diameter of the twin-screw extruder is 35 mm, the aspect ratio is 40:1, and the rotation speed is 320 rpm. The temperature of each section of the twin-screw extruder is set as follows: 345°C for the feeding section, 375°C for the melting section, 380°C for the mixing section, 360°C for the exhaust section, 365°C for the homogenizing section, and 355°C for the die; wherein the second material is added from the side feeding port at a feeding rate of 5.5 kg / h; wherein the exhaust section has an exhaust port connected to a vacuum system, and volatile small molecular substances such as alcohol solvents in the melt are removed by negative pressure, and the vacuum negative pressure is -0.09 MPa. After extrusion, granulation is performed to obtain an ultra-low temperature resistant PEEK composite material.

[0071] Comparative Example 1

[0072] The formulation and preparation process of the composite material in this case were the same as those in Example 2, except that the PEEK composite material comprised 100% of the following materials: 70% PEEK, 7% hexagonal boron nitride (lamellar thickness 20-50 nm, aspect ratio of at least 300, and phosphorus-free), 8% polyethersulfone resin microspheres, 14% untreated aramid fiber, and 1% isopropyl trioleyl titanate. All other conditions were the same as in Example 2.

[0073] Comparative Example 2

[0074] The formula and preparation process of the composite material in this case are the same as those in Example 2, except that unsurface-treated aramid fiber is used in the formula; and no pretreatment is performed during the preparation process to obtain the first material.

[0075] Comparative Example 3

[0076] The composite material formulation and preparation process for this example are the same as those in Example 2, except that the formula is: 74% PEEK resin, 10% polyethersulfone resin microspheres, 15% surface-carboxylated aramid fiber (treated as the second material in Example 2), and 1% isopropyl tri(dioctyl pyrophosphate) titanate. The composite material preparation process is the same as in S2 of Example 2. This example does not contain any thermally conductive filler.

[0077] Comparative Example 4

[0078] The composite material formulation and preparation process for this example were the same as those in Example 2, except that the formula was: 75% PEEK resin, 10% polyethersulfone resin microspheres, 15% phosphorus-doped hexagonal boron nitride flake filler, and 1% isopropyl tri(dioctyl pyrophosphate) titanate. The composite material preparation process was the same as the first material S1 and S2 in Example 2. This example did not include surface carboxylation-treated aramid fibers.

[0079] Test Case

[0080] The composite materials of the above embodiments and comparative examples were sampled and their performance was tested. The results are shown in Table 1.

[0081] Table 1 Performance of each case

[0082]

[0083]

[0084] As can be seen from Table 1, the present invention treats phosphorus-doped hexagonal boron nitride (P-BN) and polyethersulfone (PES) microspheres with a phosphate coupling agent, and then forms a composite material with surface carboxyl-treated aramid fiber and PEEK matrix resin. The PES microspheres are cavitated to absorb impact energy, the surface carboxyl-modified aramid fiber is bridged to inhibit crack propagation, and the P-BN layers are evenly dispersed to reduce stress concentration, so that the composite material has good ultra-low temperature toughness, and the ultra-low temperature toughness is significantly improved: in a -196°C liquid nitrogen environment, the notched impact strength of the material in Example 2 reaches 21.8 kJ / m 2 (Comparative Example 1 solution is 16.5kJ / m 2 , increased by 32%); At the same time, the composite material of the present invention can effectively reduce the thermal stress gradient in low temperature environment. The thermal conductivity of the material of Example 2 reaches 1.9W / mK (the thermal conductivity of the solution of Comparative Example 1 is 1.5W / mK, increased by 27%); and has low thermal expansion performance and high insulation (volume resistivity>2.5×10 15 Ω·cm), the thermal expansion coefficient of the composite material of Example 2 is 3.5×10 -5 / ℃(compared to 4.1×10 -5 / ℃ reduced by 15%), and can be used to match metal parts (such as the aluminum alloy shell of liquid hydrogen storage tanks).

[0085] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. A super-low temperature resistant PAEK composite material, characterized in that: The following materials are included in 100% weight percentage: PAEK resin 60%-75%, Polyethersulfone resin 5%-10%, 10%-20% of aramid fiber pretreated with surface carboxylation, 5%-10% of sheet-like thermal conductive filler with a thermal conductivity of at least 400W / m·K, Coupling agent 0.5%-1%.

2. The ultra-low temperature resistant PAEK composite material according to claim 1, characterized in that: The sheet-like thermal conductive filler is selected from phosphorus-doped hexagonal boron nitride, with a phosphorus content of 3wt%-5wt%, a sheet thickness of 20-50nm, and an aspect ratio of at least 300.

3. The ultra-low temperature resistant PAEK composite material according to claim 2, characterized in that: The PAEK resin is selected from one or more resins of polyetheretherketone, polyetherketone, polyetherketoneketone, polyetheretherketoneketone and polyetherketoneetherketoneketone. The particle size of the resin does not exceed 200 microns, and the melt index under the test conditions of 380°C and a load of 2.16 kg is 10-50 g / 10 min.

4. The ultra-low temperature resistant PAEK composite material according to claim 2, characterized in that: The particle size of the polyethersulfone resin does not exceed 50 microns; the length of the aramid fiber is 100-300 microns and the diameter is 10-15 microns; and the coupling agent is selected from phosphate coupling agents.

5. The ultra-low temperature resistant PAEK composite material according to claim 4, characterized in that: The coupling agent is selected from one or more of tetraisopropyl di(dioctylphosphite) titanate, a compound of di(2-ethylhexyl) phosphate and triethanolamine, a chelate of dioctylpyrophosphate titanate and triethanolamine, octadecyl phosphate, isopropyl tri(dioctylpyrophosphate) titanate, isopropyl tri(dioctylphosphite) titanate, bis(dioctylpyrophosphate) ethylene titanate, 2-fluoro-1,3-dimethylimidazolium chloride hexafluorophosphate, and isopropylated triphenyl phosphate.

6. A method for preparing an ultra-low temperature resistant PAEK composite material, characterized in that: The composite material according to any one of claims 1 to 5 comprises the following steps: S1. Preparing materials according to a formula; pre-treating a flaky thermally conductive filler having a thermal conductivity of at least 400 W / m·K and a polyethersulfone resin with a phosphate coupling agent to obtain a first material; Introducing carboxyl groups on the surface of the aramid fiber to obtain a second material; S2. Melt-blending and extruding the PAEK resin, the first material, and the second material to obtain an ultra-low temperature resistant PAEK composite material.

7. The method for preparing a super-low temperature resistant PAEK composite material according to claim 6, characterized in that: The pretreatment step of S1 is as follows: dispersing the flaky thermal conductive filler and the polyethersulfone resin in an alcohol solvent, adding the phosphate coupling agent after ultrasonic dispersion, heating to 2-8°C below the boiling point of the alcohol solvent and continuing ultrasonic dispersion for 1-5 hours, and then drying, grinding, and sieving.

8. The method for preparing a super-low temperature resistant PAEK composite material according to claim 6, characterized in that: The surface introduction method of S1 is as follows: firstly, the aramid fiber is dried to a moisture content of less than 0.1 wt%, and then treated with low-temperature oxygen plasma at a power of 60-100 W and an oxygen flow rate of 5-20 sccm for 4-10 minutes.

9. The method for preparing a super-low temperature resistant PAEK composite material according to claim 6, characterized in that: S2 uses a co-rotating meshing twin-screw extruder for melt blending. The twin-screw extruder has a screw diameter of 35 mm, an aspect ratio of 40:1, and a rotation speed of 250-350 rpm. The temperature of each section of the twin-screw extruder is set as follows: 340-350°C for the feeding section, 370-380°C for the melting section, 370-380°C for the mixing section, 345-365°C for the exhaust section, 355-365°C for the homogenizing section, and 340-355°C for the die. The second material is added from the side feeding port at a feeding rate of 3-6 kg / h. The exhaust section has an exhaust port connected to a vacuum system, and volatile small molecular substances such as alcohol solvents in the melt are removed by negative pressure. The vacuum negative pressure is -0.06 MPa to -0.09 MPa.

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