High-performance PEEK composite material and application thereof in robot skeleton

Abstract

The invention discloses a high-performance PEEK composite material and application thereof in a robot skeleton, and belongs to the technical field of special engineering plastics, the PEEK composite material comprises the following components by weight: 50-80 parts of PEEK, 10-20 parts of an elastomer, 15-30 parts of carbon fiber, and 5-10 parts of a compatilizer, monomers 1-4 are copolymerized to obtain a hyperbranched polyaryletherketone copolymer, the hyperbranched polyaryletherketone copolymer is terminated by polysiloxane and modified by maleic anhydride, the monomer 1 is 4, 4 ', 4'-trihydroxy-3, 3 ', 3'-trimethoxytriphenylmethane, the monomer 2 is isopropyl hydroquinone, the monomer 3 is hydroquinone, and the monomer 4 is 4, 4 '-difluorobenzophenone. According to the high-performance PEEK composite material and the application of the high-performance PEEK composite material in the robot skeleton, the self-made compatilizer is added, so that the PEEK and carbon fiber composite material has the characteristics of high strength, good interfacial compatibility, good bending fatigue performance and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of special engineering plastics, and specifically to a high-performance PEEK composite material and its application in a robot skeleton. Background Art

[0002] Under the global intelligent technological innovation, humanoid robots, as the crystallization of the deep integration of frontier technologies such as artificial intelligence, high-end manufacturing, and new materials, are gradually emerging. It is expected to become a new research direction after computers, smartphones, and new energy vehicles. At the same time, the design and performance of humanoid robots highly depend on breakthroughs in material technology, and their core needs to balance lightweight, high strength, wear resistance, high precision, and bionic characteristics. Among them, the application of composite materials is of great significance in robot manufacturing.

[0003] Composite materials have the advantages of high strength, high stiffness, low density, etc., which can effectively reduce the self-weight of robots, improve the movement efficiency and flexibility; they also have good corrosion resistance and high temperature resistance, and can adapt to various harsh working environments. For example, metal alloys such as aluminum alloys and titanium alloys are widely used in the manufacture of humanoid robots. Aluminum alloys have the characteristics of low density, relatively high strength, specific strength close to high alloy steels, and specific stiffness exceeding that of steel. They have good casting performance and plastic processing performance, and are also relatively ideal in terms of electrical conductivity, thermal conductivity, corrosion resistance, and weldability. Titanium alloys have higher strength and corrosion resistance, but relatively high costs, and are generally used as the structural materials of robots to support the overall framework and moving parts of robots. Carbon fiber composite materials have obvious application advantages in humanoid robots. The density of carbon fiber is only about 1 / 3 of that of steel, but its strength is much higher than that of many metal materials. This means that while maintaining the structural strength, the self-weight of humanoid robots can be significantly reduced. In addition, carbon fiber composite materials also have the characteristics of high stiffness, fatigue resistance, corrosion resistance, high temperature resistance, low thermal expansion coefficient, and high energy efficiency. These advantages make carbon fiber composite materials an ideal choice for key components such as robot manipulators and joint parts. As a special engineering plastic, PEEK materials also have high application potential in the field of humanoid robots. The specific strength of PEEK materials is about 8 times that of aluminum alloys, and they have excellent comprehensive physical and chemical properties such as heat resistance, wear resistance, and radiation resistance. Without affecting performance, PEEK materials can reduce the weight of humanoid robots, while improving the energy efficiency and load capacity of robots. In addition, PEEK materials also have excellent tensile properties, creep resistance, insulation properties, and chemical resistance, and are also widely used in fields such as semiconductors, medical treatment, and new energy vehicles.

[0004] Therefore, the composite material obtained by combining PEEK with carbon fiber can achieve the combination of light weight and high strength, and has the characteristics of high temperature resistance, high thermal stability, corrosion resistance and self-lubrication. However, the interface between PEEK and carbon fiber composite materials is the key to affecting the performance of the material. The interface phase is between the carbon fiber reinforcement and the PEEK resin matrix. The two remain independent of each other but not isolated in the region, and coordinate with each other to form a continuous transition zone. As a vulnerable area, the interface phase has an important influence on the mechanical properties, temperature resistance and moisture-heat aging resistance of the composite material. At present, the carbon fiber sizing agents used in China are mostly thermosetting epoxy resin systems, and their operating temperature is generally below 250℃, which is not suitable for PEEK materials with high melting points. In addition, the PEEK resin matrix is chemically inert, with few cross-linkable active groups in the molecular structure, and there are large differences in molecular structure with traditional thermosetting resins. The two have poor compatibility and low interface matching, which are prone to defects such as weak interface bonding, bubbles, and holes, which in turn affect the mechanical properties. Summary of the invention

[0005] In order to overcome the shortcomings of the above-mentioned prior art, the present invention provides a high-performance PEEK composite material and its application in a robot frame. By adding a homemade compatibilizer, the PEEK and carbon fiber composite material has the characteristics of high strength, interface compatibility, good bending fatigue performance, etc.

[0006] Another object of the present invention is to provide a method for preparing a high-performance PEEK composite material and its application in a robot frame.

[0007] The present invention is achieved through the following technical scheme: a high-performance PEEK composite material, which comprises the following components by weight: 50-80 parts of PEEK, 10-20 parts of elastomer, 15-30 parts of carbon fiber, and 5-10 parts of compatibilizer, wherein the compatibilizer is prepared by copolymerizing monomers 1 to 4 to obtain a hyperbranched polyaryletherketone copolymer, which is then capped with polysiloxane and modified with maleic anhydride, wherein monomer 1 is 4,4',4''-trihydroxy-3,3',3''-trimethoxytriphenylmethane, monomer 2 is isopropylhydroquinone, monomer 3 is hydroquinone, and monomer 4 is 4,4'-difluorobenzophenone.

[0008] In a specific embodiment, the grafting rate of maleic anhydride is 0.2-1%.

[0009] In a specific embodiment, the molecular weight of the polysiloxane is 3000-6000.

[0010] In a specific embodiment, the preparation method of the monomer 1 is as follows: Vanillin, guaiacol and absolute ethanol are mixed, the temperature of the system is controlled below 5°C, and an acidic ethanol solution is slowly added dropwise. Under the protection of an inert gas, the reaction is continuously stirred at a temperature below 10°C for 24 to 48 hours. The reaction solution is alternately extracted with dichloromethane and distilled water until neutral, the organic phase is separated, guaiacol is recovered by distillation at 210°C, and crystals are precipitated after cooling to obtain the monomer 1. The structure of the monomer 1 is shown in Formula 1: Formula 1.

[0011] In a specific embodiment, the acidic ethanol solution is a sulfuric acid-ethanol solution.

[0012] In a specific embodiment, the molar ratio of the monomers 1 to 3 is (0.5 to 2):(1 to 3):1, and the molar ratio of the total amount of hydroxyl groups in the monomers 1 to 3 to the fluorine in the monomer 4 is 1:1. By controlling the addition amount of the monomer 1, the degree of branching can be controlled. By controlling the molar ratio of the total amount of hydroxyl groups in the monomers 1 to 3 to the fluorine in the monomer 4, the end groups of the hyperbranched polyaryletherketone copolymer can be controlled to contain both hydroxyl groups and fluorine groups. Further, the hydroxyl groups can be capped by poly(dimethylsiloxane).

[0013] In a specific embodiment, the method for capping with poly(dimethylsiloxane) is as follows: i. The phenolic end groups of the hyperbranched polyaryletherketone copolymer are activated with a base and then subjected to nucleophilic substitution with allyl bromide to obtain an allyl-modified hyperbranched polyaryletherketone copolymer; ii. Hexamethylcyclotrisiloxane is subjected to anionic ring-opening polymerization under the action of trimethylsilanol and tetramethylammonium hydroxide. After reacting at room temperature for 100 to 200 minutes, chlorodimethylsilane and pyridine are added and the reaction continues for a period of time to obtain a hydrosilyl-terminated polydimethylsiloxane; iii. The allyl-modified hyperbranched polyaryletherketone copolymer and the hydrosilyl-terminated polydimethylsiloxane are subjected to a hydrosilylation reaction under the action of a Karstedt catalyst to obtain a poly(dimethylsiloxane)-capped hyperbranched polyaryletherketone copolymer.

[0014] In a specific embodiment, the method for maleic anhydride modification is as follows: The poly(dimethylsiloxane)-capped hyperbranched polyaryletherketone copolymer is dissolved in o-dichlorobenzene, the temperature is raised to 120 to 140°C, an o-dichlorobenzene solution of maleic anhydride and an o-dichlorobenzene solution of benzoyl peroxide are added, and the mixture is kept at 120 to 140°C for 2 to 4 h. After purification, a compatibilizer is obtained.

[0015] In a specific embodiment, the elastomer is selected from at least one of phenyl silicone rubber, fluorosilicone rubber, acrylate rubber, and ethylene-vinyl acetate copolymer, and the carbon fiber is at least one of short fiber carbon fiber and long fiber carbon fiber.

[0016] Preferably, the elastomer is selected from at least one of phenyl silicone rubber and fluorosilicone rubber.

[0017] The present invention also protects a preparation method of a PEEK composite material, comprising the following steps: (1) Weigh PEEK, an elastomer, carbon fiber and a compatibilizer, and perform mechanical blending with a high-speed mixer to obtain a mixed material; (2) Put the mixed material into a twin-screw extruder. The length-diameter ratio of the extrusion screw is 30:1 to 40:1. The temperature of the extruder is set as follows: zone T1 is 340 - 350 °C, zone T2 is 360 - 370 °C, zone T3 is 365 - 375 °C, the die temperature is 360 - 370 °C, and the rotation speed is 30 - 45 r / min; (3) Pass the extruded wire through an air-cooling device and a granulator in sequence to prepare high-performance PEEK composite material pellets.

[0018] The present invention also protects the application of the PEEK composite material in a robot skeleton.

[0019] Beneficial effects

[0020] The present invention provides a high-performance PEEK composite material. By mixing PEEK with an elastomer, carbon fiber and a compatibilizer and extruding and granulating, a PEEK composite material suitable for a robot skeleton is prepared. The PEEK composite material of the present invention achieves a balance between light weight and high rigidity, and through toughening with an elastomer, absorbs impact energy through plastic deformation, solves the problem of low-temperature brittleness of PEEK, improves the high fatigue resistance of the PEEK matrix, and combines the characteristic of the elastomer to delay crack propagation, significantly prolonging the service life of the robot joint during repeated movements.

[0021] The present invention prepares a compatibilizer of hyperbranched polyaryletherketone copolymer + polysiloxane end-capping + maleic anhydride modification. Among them, the hyperbranched polyaryletherketone is similar in structure to the PEEK resin, and can promote molecular diffusion through π-π stacking and physical entanglement, improving the compatibility between the matrix and the filler, and can significantly improve the interfacial shear strength of CF / PEEK; while the maleic anhydride group reacts with the hydroxyl groups on the surface of the carbon fiber to form covalent bonds, reducing the risk of interfacial debonding; at the same time, it improves the compatibility between the elastomer and PEEK, preventing performance degradation caused by phase separation; the polysiloxane chain segment reduces the friction coefficient, reduces the energy consumption of joint movement, improves the flexibility of the composite material under dynamic load, and avoids fracture caused by stress concentration. The hyperbranched structure reduces the melt viscosity and solves the processing difficulty of high-filled CF / PEEK. Description of the drawings

[0022] Figure 1 is the synthesis route of monomer 1; Figure 2 is the 1H NMR spectrum of monomer 1; Figure 3 It is the infrared spectrum diagram of compatibilizer 1. Specific embodiments

[0023] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative work belong to the scope of protection of the present invention.

[0024] In the embodiments, unless otherwise specified, the experimental methods used are all conventional methods, and the materials, reagents, etc. used, unless otherwise specified, can all be obtained from commercial channels.

[0025] The raw materials used in the examples and comparative examples are described as follows: PEEK: 150GL30, Victrex; Carbon fiber: T700, flaky short-cut carbon fiber 6mm, Toray, Japan, and the surface of CF was pre-treated by air plasma. Elastomer: L-108-H phenyl silicone rubber, Guangzhou Lesuo Chemical Technology Co., Ltd. Monomer 1: Self-made, the preparation method is as follows: Place 0.1 mol of vanillin and 0.5 mol of guaiacol in a 250 mL three-necked flask, add 20 mL of anhydrous ethanol, and mix 20 ml of sulfuric acid and 20 ml of anhydrous ethanol and transfer them to a constant pressure dropping funnel. Control the system temperature below 5 °C, slowly dropwise add the acidic ethanol solution, and continuously stir and react at a temperature below 10 °C for 48 hours under nitrogen protection to obtain a purple turbid liquid. The reaction solution was alternately extracted with dichloromethane and distilled water until neutral, the organic phase was separated, guaiacol was recovered by distillation at 210 °C, and red block crystals were precipitated after cooling to obtain 4,4',4''-trihydroxy-3,3',3''-trimethoxytriphenylmethane, with a yield of 74.22%. The reaction formula is as Figure 1 shown, and the nuclear magnetic resonance hydrogen spectrum is as Figure 2 shown; it can be seen from the chemical shifts and integrals on the nuclear magnetic resonance hydrogen spectrum that 4,4',4''-trihydroxy-3,3',3''-trimethoxytriphenylmethane was successfully synthesized.

[0026] Monomer 2: Isopropylhydroquinone, 95%, Shanghai Yuanye Bio-Technology Co., Ltd. Monomer 3: Hydroquinone, 99%, Panhua Chemistry (Shanghai) Co., Ltd. Monomer 4: 4,4'-Difluorobenzophenone, 99.9%, Jiangsu Xinhan New Materials Co., Ltd. Compatibilizer 1: Self-made, the preparation method is as follows: S1. Add 0.01 mol of monomer 1, 0.01 mol of monomer 2, 0.01 mol of monomer 3, 0.035 mol of monomer 4, 0.0105 mol of alkali metal carbonate (K2CO3:Na2CO3 = 19:1), 16.5 ml of sulfolane, and 10 ml of toluene into a three-necked flask. Under a nitrogen atmosphere, control the temperature at 150 °C. After heat preservation for 2 h, raise the temperature to 170 °C for prepolymerization for 1 h, distill out the remaining toluene, raise the temperature to 200 °C for polycondensation for 3.5 h to prepare a copolymer. Discharge the obtained copolymer into deionized water, dry and crush it, and then wash it with ethanol and deionized water respectively to obtain a white powder; S2. Take 3.95 g of the copolymer obtained in step S1 and mix it with 90 ml of tetrahydrofuran in a two-necked flask, and introduce nitrogen for replacement protection; add 235 mg of sodium hydride, stir and react for about 15 minutes, dropwise add 0.47 ml of allyl bromide, and continue to react at room temperature for 24 hours; after the reaction is completed, wash the reaction mixture 3 times with saturated brine; extract the product with chloroform, and combine the organic phases; precipitate the chloroform solution in methanol again, collect the solid, and dry it under vacuum to obtain an allyl-modified copolymer; Under argon protection, add 11.3 mmol of hexamethylcyclotrisiloxane and 9 ml of diethyl ether solution into a Schlenk tube, add 1.25 mmol of trimethylsilanol, inject 0.18 ml of a toluene solution of tetramethylammonium hydroxide with a concentration of 0.625 mol / L as a catalyst, stir and react at 25 °C for 140 minutes, add 2.2 mmol of chlorodimethylsilane and 7.5 mmol of pyridine, and continue to stir for more than 24 hours to ensure hydrosilyl end-capping. Concentrate the reaction solution and wash it with acetonitrile multiple times to obtain hydrosilyl end-capped polydimethylsiloxane with a yield of 92.3%. Determined by GPC, the molecular weight is 3200, and the molecular weight distribution coefficient is 1.09; Under argon protection, mix 0.25 g of the allyl-modified copolymer and 0.51 g of hydrosilyl end-capped polydimethylsiloxane, add 5 ml of anhydrous toluene and 8 drops of Karstedt's catalyst, stir and react at 25 °C, monitor the reaction process by ¹H NMR. After the reaction is completed, concentrate the mixture, wash it with acetone to remove residual PDMS, and dry it under vacuum to obtain a partially polysiloxane end-capped hyperbranched poly(aryl ether ketone) copolymer; S3. Take 1 g of the partially polysiloxane-capped copolymer and add it to a three-necked flask. Add 20 ml of o-dichlorobenzene, and heat it to complete dissolution under nitrogen protection. Then heat it to 130 °C. Dissolve 0.1 g of maleic anhydride in 5 ml of o-dichlorobenzene and directly add it to the three-necked flask. Dissolve 0.04 g of benzoyl peroxide in 5 ml of o-dichlorobenzene and add it dropwise within 1 h. Keep it at 130 °C for 3 h. Pour the product into acetone to precipitate, filter, dry, and crush it to obtain the hyperbranched polyaryletherketone grafted with maleic anhydride and capped with polysiloxane. The grafting rate measured by the alkali titration method is 0.68 wt%. The structure of the compatibilizer is analyzed by an infrared spectrometer (Thermo Nicolet, is 20). The morphology is powder. Select the ATR mode at room temperature, and the scanning range is 4000 cm -1 ~500 cm -1 -1, the number of scans is 32 times, and the resolution is 4 cm -1 -1. Automatically deduct the atmospheric background. Among them, the antisymmetric vibration peak and symmetric vibration peak of the maleic anhydride carbonyl group are observed at 1780 cm -1 -1 and 1748 cm -1 -1; a broad and strong Si-O-Si stretching vibration peak is detected at 1015 cm -1 -1, which proves that the hyperbranched polyaryletherketone is successfully capped with polysiloxane and modified with maleic anhydride.

[0027] Compatibilizer 2: Compared with Compatibilizer 1, the difference is that in step S2, as determined by GPC, the molecular weight of the polysiloxane is 4700, and the molecular weight distribution coefficient is 1.08. The specific method is as follows: the addition amount of trimethylsilanol is adjusted to 0.83 mmol, the addition amount of chlorodimethylsilane is adjusted to 4.2 mmol, and the addition amount of pyridine is adjusted to 6.6 mmol; Compatibilizer 3: Compared with Compatibilizer 1, the difference is that in step S2, as determined by GPC, the molecular weight of the polysiloxane is 6000, and the molecular weight distribution coefficient is 1.07. The specific method is as follows: the addition amount of trimethylsilanol is adjusted to 0.63 mmol, the addition amount of chlorodimethylsilane is adjusted to 3.2 mmol, and the addition amount of pyridine is adjusted to 5.0 mmol; Compatibilizer 4: Compared with Compatibilizer 1, the difference is that in step S2, as determined by GPC, the molecular weight of the polysiloxane is 7000, and the molecular weight distribution coefficient is 1.06. The specific method is as follows: the addition amount of trimethylsilanol is adjusted to 0.45 mmol, the addition amount of chlorodimethylsilane is adjusted to 2.2 mmol, and the addition amount of pyridine is adjusted to 3.5 mmol; Comparative compatibilizer 5: Compared with Compatibilizer 1, the difference is that maleic anhydride grafting is not carried out, that is, step S3 is not carried out; Comparative compatibilizer 6: Compared with Compatibilizer 1, the difference is that polysiloxane capping is not carried out, that is, step S2 is not carried out; Comparative compatibilizer 7: Compared with compatibilizer 1, the difference is that the compatibilizer is linear, that is, monomer 1 is not added in step S1, and the addition amount of monomer 4 is modified to 0.02 mol; Comparative compatibilizer 8: A commercially available compatibilizer, glycidyl methacrylate graft, specifically POE-g-GMA, SOG-03, Jia Yirong; Unless otherwise specified, the component raw materials used in each example and comparative example of the present invention are all commercially available raw materials, and the component raw materials used in each parallel experiment are all of the same kind.

[0028] Examples and comparative examples A PEEK composite material and its preparation method, the weight part formula is shown in Table 1, and the preparation method is as follows: 1) Weigh PEEK, elastomer, carbon fiber and compatibilizer and perform mechanical blending with a high-speed mixer to obtain a mixed material; 2) Put the mixed material into a twin-screw extruder, the aspect ratio of the extrusion screw is 30:1, the temperature of the extruder is set at 345 °C in zone T1, 365 °C in zone T2, 370 °C in zone T3, the die temperature is 365 °C, and the rotation speed is 30 r / min; 3) Pass the extruded wire through an air-cooling device and a granulator in sequence to prepare high-performance PEEK composite material pellets.

[0029] Table 1 Composition and ratio of PEEK composite material (parts by weight)

[0030] Perform the following performance tests on a PEEK composite material prepared in the examples and comparative examples, and the results are shown in Table 2 respectively.

[0031] 1. Flexural strength: The PEEK composite material is molded into a specimen with dimensions of 127×12.7×3.2 mm and tested according to ASTM D7264-21, the test rate is 1 mm / min, and each group of test results contains 5 valid data.

[0032] 2. Flexural modulus: The PEEK composite material is molded into a specimen with dimensions of 127×12.7×3.2 mm and tested according to ASTM D7264-21, the test rate is 1 mm / min, and each group of test results contains 5 valid data.

[0033] 3. Porosity: Use quick-drying glue to fix the PEEK composite material between two building blocks, polish it with 500, 1000, 2000 and 2500-mesh sandpapers in sequence, then polish it with polishing powder, and finally ultrasonically clean it. Measure the porosity of the CF / PEKK composite material according to GB / T 3365−2008 with the help of an upright multi-functional microscope and Image J software.

[0034] 4. Interfacial shear strength: The PEEK composite material was molded into specimens with dimensions of 127×12.7×3.2 mm and tested according to ASTM D2344-22 at a test rate of 1 mm / min. Each set of test results contains 5 valid data.

[0035] 5. Bending fatigue performance test: The PEEK composite materials prepared in the examples and comparative examples were tested according to the standard of GB / T35465.1-2017, with an alternating cycle frequency of 25 Hz and a limiting load of 60% of the maximum stress; Table 2 Performance test results of PEEK composite materials

[0036] It can be seen from Examples 3 to 6 that when the molecular weight of the polysiloxane in the compatibilizer is between 3000 and 6000, the mechanical properties, porosity and bending fatigue performance of the PEEK composite material are the best. When the polysiloxane chain segment is too short (low molecular weight), it is difficult to form a continuous lubricating layer at the PEEK / elastomer interface. When the polysiloxane chain is too long (high molecular weight), the steric hindrance effect will hinder the bonding of maleic anhydride groups with the hydroxyl groups on the carbon fiber surface.

[0037] It can be seen from Example 3 and Comparative Example 1 that when maleic anhydride modification is not carried out, the interfacial bonding force between carbon fiber and PEEK becomes weak, the porosity becomes high, and the interfacial shear strength decreases, thus affecting the mechanical properties.

[0038] It can be seen from Example 3 and Comparative Example 2 that when polysiloxane capping is not carried out, phase separation is likely to occur between the elastomer and PEEK, which will also lead to an increase in porosity, thus affecting the mechanical properties of the PEEK composite material.

[0039] It can be seen from Example 3 and Comparative Example 3 that when a compatibilizer with a linear structure is used, the linear structure of the compatibilizer contains only 2 terminal functional groups, the modification amount of polysiloxane is insufficient, and the linear molecule is difficult to effectively entangle the PEEK chain segment through π-π stacking. The low melting viscosity characteristics of the hyperbranched structure ensure high filling and processing in the PEEK composite material, and its multi-terminal group design maximizes the interfacial modification effect.

[0040] The preferred embodiments of the present invention disclosed above are only used to help illustrate the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to the specific embodiments described. Obviously, many modifications and variations can be made according to the content of this specification. These embodiments are selected and specifically described in this specification to better explain the principle and practical application of the present invention, so that those skilled in the art can understand and utilize the present invention well. The present invention is only limited by the claims and their full scope and equivalents.

Claims

1. A high-performance PEEK composite material, characterized in that, By weight parts, it includes the following components: 50 - 80 parts of PEEK, 10 - 20 parts of elastomer, 15 - 30 parts of carbon fiber, 5 - 10 parts of compatibilizer. The compatibilizer is obtained by copolymerizing monomers 1 to 4 to get a hyperbranched polyaryletherketone copolymer, and then end-capping with polysiloxane and modifying with maleic anhydride. Among them, monomer 1 is 4,4',4''-trihydroxy-3,3',3''-trimethoxytriphenylmethane, monomer 2 is isopropylhydroquinone, monomer 3 is hydroquinone, and monomer 4 is 4,4'-difluorobenzophenone.

2. The PEEK composite material according to claim 1, wherein The grafting rate of the maleic anhydride is 0.2 - 1%.

3. The PEEK composite material according to claim 1, characterized in that, The molecular weight of the polysiloxane is 3000 - 6000.

4. The PEEK composite material according to claim 1, wherein The preparation method of monomer 1 is: Mix vanillin, guaiacol and absolute ethanol, control the system temperature below 5°C, slowly dropwise add an acidic ethanol solution, and continuously stir and react at a temperature below 10°C for 24 - 48 hours under the protection of an inert gas. The reaction solution is alternately extracted with dichloromethane and distilled water until neutral, the organic phase is separated, guaiacol is recovered by distillation at 210°C, and crystals are precipitated after cooling to obtain monomer 1. The structure of monomer 1 is as shown in formula 1: Formula 1.

5. The PEEK composite material according to claim 1, wherein The molar ratio of monomers 1 to 3 is (0.5 - 2):(1 - 3):1, and the total molar amount of hydroxyl groups in monomers 1 to 3 and the molar ratio of fluorine in monomer 4 is 1:

1.

6. The PEEK composite material according to claim 1, wherein, The method for end-capping with polysiloxane is: i. Activate the phenolic end groups of the hyperbranched polyaryletherketone copolymer with a base and carry out nucleophilic substitution with allyl bromide to obtain an allyl-modified hyperbranched polyaryletherketone copolymer; ii. Carry out anionic ring-opening polymerization of hexamethylcyclotrisiloxane under the action of trimethylsilanol and tetramethylammonium hydroxide, react at room temperature for 100 - 200 minutes, then add chlorodimethylsilane and pyridine and continue to react for a period of time to obtain a hydrosilyl-terminated polydimethylsiloxane; iii. Carry out a hydrosilylation reaction of the allyl-modified hyperbranched polyaryletherketone copolymer and the hydrosilyl-terminated polydimethylsiloxane under the action of a Karstedt catalyst to obtain a polysiloxane-terminated hyperbranched polyaryletherketone copolymer.

7. The PEEK composite material according to claim 1, wherein, The method for modifying with maleic anhydride is: Dissolve the polysiloxane-terminated hyperbranched polyaryletherketone copolymer in o-dichlorobenzene, heat up to 120 - 140°C, add an o-dichlorobenzene solution of maleic anhydride and an o-dichlorobenzene solution of benzoyl peroxide, keep the temperature at 120 - 140°C for 2 - 4 h, and obtain the compatibilizer after purification.

8. The PEEK composite material according to claim 1, wherein The elastomer is selected from at least one of phenyl silicone rubber, fluorosilicone rubber, acrylate rubber, ethylene-vinyl acetate copolymer; the carbon fiber is at least one of short fiber carbon fiber or long fiber carbon fiber.

9. The preparation method of the PEEK composite material according to any one of claims 1 to 8, characterized in that, It includes the following steps: (1) Weigh PEEK, elastomer, carbon fiber and compatibilizer and carry out mechanical blending with a high-speed mixer to obtain a mixed material; (2) Put the mixed material into a twin-screw extruder. The length-diameter ratio of the extrusion screw is 30:1 - 40:

1. The temperature of the extruder is set as follows: zone T1 is 340 - 350°C, zone T2 is 360 - 370°C, zone T3 is 365 - 375°C, the die temperature is 360 - 370°C, and the rotation speed is 30 - 45 r / min; (3)The extruded wire material is successively passed through an air-cooling device and a granulator to prepare high-performance PEEK composite material pellets.

10. Application of the PEEK composite material according to any one of claims 1 to 8 in a robot skeleton.

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