Medical-grade PEEK composite material for 3D printing and preparation method of medical-grade PEEK composite material

Abstract

The invention discloses a medical-grade PEEK composite material for 3D printing and a preparation method of the medical-grade PEEK composite material, relates to the technical field of 3D printing, and solves the problem of low biological activity of an existing PEEK material. The medical-grade PEEK composite material is prepared from the following raw materials in parts by weight: 80-95 parts of a polyether-ether-ketone matrix, 5-15 parts of a bioactive filler, 0.5-5 parts of an interface modifier and 0.1-3 parts of a heat conduction and nucleation enhancer, the bioactive filler comprises nano-hydroxyapatite and bioactive glass in a weight ratio of (1-5): (5-1). The natural bone environment can be effectively simulated, the biological activity of the composite material is improved, and cell adhesion and proliferation are promoted, so that the cell proliferation rate is increased, and the antibacterial effect and the mechanical property of the composite material can be effectively improved.

Description

Technical Field

[0001] This invention relates to the field of 3D printing technology, and specifically to a medical-grade PEEK composite material for 3D printing and its preparation method. Background Technology

[0002] Polyetheretherketone (PEEK), as a high-performance specialty engineering plastic, has shown great potential in 3D printing (especially fused deposition modeling, FDM) medical-grade PEEK composites in aerospace, medical implants, automotive manufacturing and other fields due to its excellent mechanical strength, high temperature resistance, chemical corrosion resistance and biocompatibility.

[0003] In the fields of medical devices and biomedical materials, polyetheretherketone (PEEK) is widely used in orthopedic implants, dental restorative materials, and other areas due to its excellent mechanical properties, chemical resistance, high-temperature resistance, and good biocompatibility. However, despite its outstanding mechanical properties, the low bioactivity of PEEK materials limits its promotion and use in more biomedical-grade PEEK composite materials.

[0004] Bioactivity refers to the ability of a material to interact with biological tissues and promote cell growth and tissue regeneration within a living organism. For implant materials, good bioactivity can effectively promote cell adhesion, proliferation, and differentiation, thereby improving the integration and functionality of the implant. Due to the characteristics of its chemical structure, PEEK materials exhibit low bioactivity and are difficult to promote the healing and repair of surrounding tissues. This deficiency prevents PEEK from achieving its intended effect in some clinical medical-grade PEEK composite materials, especially in situations requiring close integration with biological tissues.

[0005] To address the issue of low bioactivity in PEEK materials, researchers have explored various modification methods in recent years, such as surface modification, filling with bioactive materials, and doping with biominerals, in an attempt to improve the biocompatibility and bioactivity of PEEK materials. Therefore, developing novel PEEK composite materials with excellent bioactivity and their preparation methods has become an important research topic in biomedical materials. Summary of the Invention

[0006] To address the above shortcomings, this invention provides a medical-grade PEEK composite material for 3D printing and its preparation method. This solves the problem of low bioactivity in existing PEEK materials, effectively mimics the natural bone environment, improves the bioactivity of the composite material, promotes cell adhesion and proliferation, thereby increasing the cell proliferation rate. It also effectively improves the antibacterial effect and mechanical properties of the composite material. The specific technical solution is as follows: A medical-grade PEEK composite material for 3D printing is made from the following raw materials in parts by weight: 80-95 parts of polyetheretherketone (PEEK) matrix, 5-15 parts of bioactive filler, 0.5-5 parts of interface modifier, and 0.1-3 parts of thermal conductivity and nucleation enhancer; the bioactive filler comprises nano-hydroxyapatite and bioactive glass in a weight ratio of (1-5):(5-1). The bioactive filler is a compound of surface-activated nano-hydroxyapatite and bioactive glass.

[0007] Preferably, the nano-hydroxyapatite has an average particle size of 30–100 nm and an aspect ratio greater than 5.

[0008] Preferably, the particle size of the bioactive glass is 1–10 μm. Further, the raw materials constituting the bioactive glass include SiO2, CaO, P2O5, and Na2O.

[0009] Preferably, the interface modifier is a silane coupling agent or a titanate coupling agent.

[0010] Preferably, the thermal conductivity and nucleation enhancer is nano-graphene. More preferably, the thermal conductivity and nucleation enhancer is nano-sized titanium dioxide and / or surface-functionalized nano-graphene.

[0011] Preferably, the nanographene is a nanographene sheet with surface functionalization via hydroxyl or carboxyl groups, and its specific surface area is 100-500 m² / g.

[0012] Preferably, the bioactive filler further includes nano-titanium dioxide, which accounts for 1 to 5% of the total weight of the polyether ether ketone matrix.

[0013] Preferably, the melt index of the polyether ether ketone (PEEK) matrix is ​​5 to 50 g / 10 min.

[0014] Preferably, a method for preparing a medical-grade PEEK composite material for 3D printing includes the following steps: S1. Surface activation treatment of bioactive filler: Nano-hydroxyapatite and bioactive glass are dispersed in anhydrous ethanol, an interface modifier is added, and the mixture is ultrasonically stirred at 60-80℃ for 1-3 hours. Then, the mixture is filtered and dried to obtain surface-activated bioactive filler. S2. Premixing: Under the protection of nitrogen or argon atmosphere, the bioactive filler, polyether ether ketone matrix powder, and thermally conductive and nucleating enhancer from step S1 are mixed at a speed of 300-1000 r / min for 10-60 min to obtain a uniform premix. S3. Melt blending and granulation: The premixed material from step S2 is fed into a twin-screw extruder for melt blending, extrusion, cooling, traction and granulation, and then fed into a single-screw extruder for melt extrusion, cooling and shaping, traction and winding to produce FDM 3D printing filament, thus obtaining the medical-grade PEEK composite material.

[0015] Preferably, in step S3, the processing temperature of the twin-screw extruder is: 290-300℃ in zone 1, 300-310℃ in zone 2, 310-320℃ in zone 3, 320-330℃ in zone 4, and 325-330℃ at the die head; the screw speed is 200-400 r / min.

[0016] Preferably, in step S3, the processing temperature of the single-screw extruder is: 300-310℃ in zone 1, 310-320℃ in zone 2, 320-330℃ in zone 3, and 325-330℃ at the die head.

[0017] An application of a medical-grade PEEK composite material prepared by the method described above, characterized in that it is used to prepare medical implants, wherein the medical implants are prepared by FDM 3D printing technology, and the medical implants are orthopedic implants, dental prostheses or cranial prostheses.

[0018] The present invention achieves at least the following beneficial effects: 1. This invention creatively combines nano-hydroxyapatite (high aspect ratio, which is conducive to network construction) with bioactive glass (rapid ion release) in a specific ratio. Some embodiments also add nano-titanium dioxide to effectively simulate the natural bone environment, improve the bioactivity of the composite material, promote cell adhesion and proliferation, and thus increase the cell proliferation rate.

[0019] 2. The addition of thermal conductivity and nucleation enhancer in this invention improves crystallization uniformity during the printing process and reduces internal stress; at the same time, it works together with bioactive filler to induce bone-like apatite deposition more quickly in vivo, significantly improving bioactivity and further increasing cell proliferation rate.

[0020] 3. This invention introduces surface-functionalized graphene nanoparticles, which improves the antibacterial ability of the composite material and helps prevent postoperative infection of the implant.

[0021] 4. In the preparation process, this invention combines ultrasonic treatment and gradient melt extrusion to improve the mechanical properties (flexural strength, tensile strength, etc.) of the composite material. Detailed Implementation

[0022] The specific embodiments of the present invention are described in detail below, but it should be understood that the scope of protection of the present invention is not limited to the specific embodiments. Unless otherwise defined, all technical terms used below have the same meaning as commonly understood by those skilled in the art. The technical terms used herein are for the purpose of describing specific embodiments only and are not intended to limit the scope of protection of the present invention. Unless otherwise specifically stated, all raw materials, reagents, instruments, and equipment used in the present invention are commercially available or can be prepared by existing methods.

[0023] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0024] This application provides a medical-grade PEEK composite material for 3D printing. Through specific formulation and preparation methods, its bioactivity is effectively improved, thus providing a more reliable material choice for clinical medical-grade PEEK composite materials and meeting the urgent needs of the medical industry for high-performance, biocompatible materials. Therefore, the medical-grade PEEK composite material for 3D printing of this invention not only has significant scientific value but also broad prospects for medical-grade PEEK composite materials, providing new ideas and solutions for the development of biomedical materials.

[0025] Example 1 A medical-grade PEEK composite material for 3D printing is made from the following parts by weight of raw materials: 80 parts of polyetheretherketone (PEEK) matrix, melt index of 5 g / 10 min; 5 parts of bioactive filler; 0.5 parts of silane coupling agent; 0.1 parts of nano-graphene have a specific surface area of ​​100 m² / g.

[0026] Specifically, the bioactive filler includes nano-hydroxyapatite and bioactive glass in a weight ratio of 1:5; the bioactive filler also includes nano-titanium dioxide, which accounts for 1% of the total weight of the polyetheretherketone matrix; the average particle size of the nano-hydroxyapatite is 30 nm and the aspect ratio is greater than 5; the particle size of the bioactive glass is 1 μm.

[0027] A method for preparing a medical-grade PEEK composite material for 3D printing includes the following steps: S1. Surface activation treatment of bioactive filler: Nano-hydroxyapatite and bioactive glass are dispersed in anhydrous ethanol, an interface modifier is added, and the mixture is ultrasonically stirred at 60°C for 1 hour. Then, the mixture is filtered and dried to obtain surface-activated bioactive filler. S2. Premixing: Under the protection of nitrogen or argon atmosphere, the bioactive filler, polyether ether ketone matrix powder, and thermally conductive and nucleating enhancer from step S1 are mixed at a speed of 300 r / min for 10 min to obtain a uniform premix. S3. Melt blending and granulation: The premixed material from step S2 is fed into a twin-screw extruder for melt blending, extrusion, cooling, traction and granulation, and then fed into a single-screw extruder for melt extrusion, cooling and shaping, traction and winding to produce FDM 3D printing filament, thus obtaining the medical-grade PEEK composite material. The processing temperatures for a twin-screw extruder are: Zone 1 290℃, Zone 2 300℃, Zone 3 310℃, Zone 4 320℃, and Die head 325℃; the screw speed is 200 r / min. The processing temperatures for a single-screw extruder are: Zone 1 300℃, Zone 2 310℃, Zone 3 320℃, and Die head 325℃.

[0028] Example 2 A medical-grade PEEK composite material for 3D printing is made from the following parts by weight of raw materials: 95 parts of polyetheretherketone (PEEK) matrix, melt index of 50 g / 10 min; 15 parts of bioactive filler; 5 parts of titanate coupling agent; Three parts of nano-graphene, with a specific surface area of ​​500 m² / g.

[0029] Specifically, the bioactive filler includes nano-hydroxyapatite and bioactive glass in a weight ratio of 5:1; the bioactive filler also includes nano-titanium dioxide, which accounts for 5% of the total weight of the polyether ether ketone matrix; the average particle size of the nano-hydroxyapatite is 100 nm and the aspect ratio is greater than 5; the particle size of the bioactive glass is 10 μm.

[0030] A method for preparing a medical-grade PEEK composite material for 3D printing includes the following steps: S1. Surface activation treatment of bioactive filler: Nano hydroxyapatite and bioactive glass are dispersed in anhydrous ethanol, an interface modifier is added, and the mixture is ultrasonically stirred at 80°C for 3 hours. Then, the mixture is filtered and dried to obtain surface-activated bioactive filler. S2. Premixing: Under the protection of nitrogen or argon atmosphere, the bioactive filler, polyether ether ketone matrix powder, and thermally conductive and nucleating enhancer from step S1 are mixed at a speed of 1000 r / min for 60 min to obtain a uniform premix. S3. Melt blending and granulation: The premixed material from step S2 is fed into a twin-screw extruder for melt blending, extrusion, cooling, traction and granulation, and then fed into a single-screw extruder for melt extrusion, cooling and shaping, traction and winding to produce FDM 3D printing filament, thus obtaining the medical-grade PEEK composite material. The processing temperatures of the twin-screw extruder are: Zone 1 300℃, Zone 2 310℃, Zone 3 320℃, Zone 4 330℃, and the die head 330℃; the screw speed is 400 r / min. The processing temperatures of the single-screw extruder are: Zone 1 310℃, Zone 2 320℃, Zone 3 330℃, and the die head 330℃.

[0031] Example 3 A medical-grade PEEK composite material for 3D printing is made from the following parts by weight of raw materials: 85 parts of polyetheretherketone (PEEK) matrix, melt index of 10 g / 10 min; 8 parts of bioactive filler; One part of silane coupling agent and one part of titanate coupling agent; and the weight ratio of silane coupling agent to titanate coupling agent is 1:1; One part of nano-graphene has a specific surface area of ​​200 m² / g.

[0032] Specifically, the bioactive filler includes nano-hydroxyapatite and bioactive glass in a weight ratio of 2:4; the bioactive filler also includes nano-titanium dioxide, which accounts for 2% of the total weight of the polyetheretherketone matrix; the average particle size of the nano-hydroxyapatite is 40 nm and the aspect ratio is greater than 5; the particle size of the bioactive glass is 3 μm.

[0033] A method for preparing a medical-grade PEEK composite material for 3D printing includes the following steps: S1. Surface activation treatment of bioactive filler: Nano-hydroxyapatite and bioactive glass are dispersed in anhydrous ethanol, an interface modifier is added, and the mixture is ultrasonically stirred at 65°C for 1.5 h. Then, it is filtered and dried to obtain surface-activated bioactive filler. S2. Premixing: Under the protection of nitrogen or argon atmosphere, the bioactive filler, polyether ether ketone matrix powder, and thermally conductive and nucleating enhancer from step S1 are mixed at a speed of 400 r / min for 20 min to obtain a uniform premix. S3. Melt blending and granulation: The premixed material from step S2 is fed into a twin-screw extruder for melt blending, extrusion, cooling, traction and granulation, and then fed into a single-screw extruder for melt extrusion, cooling and shaping, traction and winding to produce FDM 3D printing filament, thus obtaining the medical-grade PEEK composite material. The processing temperatures of the twin-screw extruder are: Zone 1 292℃, Zone 2 303℃, Zone 3 312℃, Zone 4 323℃, and Die head 326℃; the screw speed is 250 r / min. The processing temperatures of the single-screw extruder are: Zone 1 302℃, Zone 2 312℃, Zone 3 322℃, and Die head 326℃.

[0034] Example 4 A medical-grade PEEK composite material for 3D printing is made from the following parts by weight of raw materials: 90 parts of polyetheretherketone (PEEK) matrix, melt index of 40 g / 10 min; 13 parts of bioactive filler; 4 parts of titanate coupling agent; 2.5 parts of nano-graphene, with a specific surface area of ​​400 m² / g.

[0035] Specifically, the bioactive filler comprises nano-hydroxyapatite and bioactive glass in a weight ratio of 4:2; the average particle size of the nano-hydroxyapatite is 90 nm and the aspect ratio is greater than 5; the particle size of the bioactive glass is 8 μm.

[0036] A method for preparing a medical-grade PEEK composite material for 3D printing includes the following steps: S1. Surface activation treatment of bioactive filler: Nano-hydroxyapatite and bioactive glass are dispersed in anhydrous ethanol, an interface modifier is added, and the mixture is ultrasonically stirred at 75°C for 2.5 h. Then, it is filtered and dried to obtain surface-activated bioactive filler. S2. Premixing: Under the protection of nitrogen or argon atmosphere, the bioactive filler, polyether ether ketone matrix powder, and thermally conductive and nucleating enhancer from step S1 are mixed at a speed of 900 r / min for 50 min to obtain a uniform premix. S3. Melt blending and granulation: The premixed material from step S2 is fed into a twin-screw extruder for melt blending, extrusion, cooling, traction and granulation, and then fed into a single-screw extruder for melt extrusion, cooling and shaping, traction and winding to produce FDM 3D printing filament, thus obtaining the medical-grade PEEK composite material. The processing temperatures of the twin-screw extruder are: Zone 1 299℃, Zone 2 309℃, Zone 3 318℃, Zone 4 328℃, and Die head 329℃; the screw speed is 350 r / min. The processing temperatures of the single-screw extruder are: Zone 1 308℃, Zone 2 318℃, Zone 3 328℃, and Die head 329℃.

[0037] Example 5 A medical-grade PEEK composite material for 3D printing is made from the following parts by weight of raw materials: 88 parts of polyetheretherketone (PEEK) matrix, melt index of 25 g / 10 min; 10 parts of bioactive filler; 3 parts silane coupling agent; Two parts of nano-graphene, with a specific surface area of ​​300 m² / g.

[0038] Specifically, the bioactive filler includes nano-hydroxyapatite and bioactive glass in a weight ratio of 3:3; the bioactive filler also includes nano-titanium dioxide, which accounts for 3% of the total weight of the polyetheretherketone matrix; the average particle size of the nano-hydroxyapatite is 60 nm and the aspect ratio is greater than 5; the particle size of the bioactive glass is 5 μm.

[0039] A method for preparing a medical-grade PEEK composite material for 3D printing includes the following steps: S1. Surface activation treatment of bioactive filler: Nano-hydroxyapatite and bioactive glass are dispersed in anhydrous ethanol, an interface modifier is added, and the mixture is ultrasonically stirred at 70°C for 2 hours. Then, the mixture is filtered and dried to obtain surface-activated bioactive filler. S2. Premixing: Under the protection of nitrogen or argon atmosphere, the bioactive filler, polyether ether ketone matrix powder, and thermally conductive and nucleating enhancer from step S1 are mixed at a speed of 700 r / min for 30 min to obtain a uniform premix. S3. Melt blending and granulation: The premixed material from step S2 is fed into a twin-screw extruder for melt blending, extrusion, cooling, traction and granulation, and then fed into a single-screw extruder for melt extrusion, cooling and shaping, traction and winding to produce FDM 3D printing filament, thus obtaining the medical-grade PEEK composite material. The processing temperatures of the twin-screw extruder are: Zone 1 295℃, Zone 2 305℃, Zone 3 315℃, Zone 4 325℃, and Die head 327℃; the screw speed is 300 r / min. The processing temperatures of the single-screw extruder are: Zone 1 305℃, Zone 2 315℃, Zone 3 325℃, and Die head 328℃.

[0040] Comparative Example 1 The difference from Example 1 is that no bioactive filler was added, while other conditions remained the same.

[0041] Comparative Example 2 The difference from Example 1 is that the bioactive filler contains only bioactive glass, while other conditions remain the same.

[0042] Comparative Example 3 The difference from Example 1 is that no nano-graphene was added, while other conditions remained the same.

[0043] Comparative Example 4 The difference from Example 1 is that in the preparation process, the ultrasonic treatment in step S1 is ultrasonic stirring at 90°C for 3.5 hours, while other conditions remain unchanged.

[0044] Comparative Example 5 The difference from Example 1 is that in the preparation process, no gradient treatment is performed during melt blending and extrusion in step S3, that is, the processing temperature of the twin-screw extruder is 310°C and the die head is 325°C; other conditions remain unchanged.

[0045] Comparative Example 6 The difference from Example 1 is that, in the preparation process, no gradient treatment is performed during the melt extrusion in step S3, and the processing temperature of the single screw extruder is 310°C, the die head is 325°C, and other conditions remain unchanged.

[0046] Performance testing: Flexural modulus and flexural strength: Tested using a bending testing machine (Jinan Chenxin Testing Machine Manufacturing Co., Ltd.) according to ISO178-2010 standard, with a test loading speed of 0.2 mm / min. Five samples were tested in each group, and the average value of the results was taken. Tensile strength: The test was conducted on a Shimadzu AGS-X universal testing machine. The test specimens were prepared according to GB / T 1040.1-2018 "Determination of tensile properties of plastics". The loading speed of the specimens was 0.2 mm / min. Five samples were tested in each group, and the average value of the results was taken.

[0047] Biocompatibility: Tested according to ISO 10993 method; Bioactivity (cell proliferation rate): The cell proliferation rate (%) was determined by cell proliferation assay and recorded. Antibacterial rate test: determined using ISO 20776-1 method.

[0048] The experimental results of the medical-grade PEEK composite materials prepared in Examples 1-5 and Comparative Examples 1-6 are shown in Table 1 below.

[0049] Table 1 The experimental data show that the medical-grade PEEK composite material prepared in this application has excellent bioactivity, antibacterial properties and mechanical properties.

[0050] The composite material prepared in Comparative Example 1 has extremely low bioactivity (+5%), weak antibacterial properties (10.3%), and significantly reduced mechanical strength. This is because the bioactive filler of the present invention not only provides a source of bioactivity and antibacterial properties, but also enhances and toughens the PEEK matrix due to its good interfacial bonding, thus meeting the requirements of high-performance implants.

[0051] The composite material prepared in Comparative Example 2 showed significantly lower bioactivity (+18%) and antibacterial rate (65.2%) compared to Example 1, and also exhibited poorer mechanical properties. This is because the "nano-hydroxyapatite-bioactive glass" composite system of the present invention can improve performance, while a single bioactive glass may fail to achieve the effect of the composite system due to poor bonding with the matrix or its own performance defects.

[0052] The mechanical properties and bioactivity of Comparative Example 3 were comparable to those of Example 1, but the antibacterial rate dropped drastically to 15.5%. This is because the addition of nano-graphene in this invention not only did not impair the mechanical properties and biocompatibility of the matrix, but also endowed the material with super antibacterial properties.

[0053] Comparative Example 4 showed a significant decline in all performance indicators. This is because the ultrasonic assistance of this invention and the ultrasonic temperature and time specified in this application enable the filler to be uniformly dispersed and enhance the interfacial bonding ability. Without ultrasonic treatment, the filler will severely agglomerate in the matrix, becoming stress defect points, leading to deterioration of mechanical properties. At the same time, the distribution of bioactive points is uneven, and the bioactivity and antibacterial properties are also greatly reduced. However, ultrasonic dispersion treatment alone cannot achieve the expected results. In long-term research and development experiments, the inventors found that excessively high or low ultrasonic temperatures are not conducive to uniform material dispersion, and even extending the dispersion time does not achieve the expected results. Under the ultrasonic dispersion conditions of this invention, the results achieved in terms of both material performance and economic benefits are better.

[0054] The mechanical properties (especially flexural and tensile strength) of Comparative Example 5 were significantly lower than those of Example 1. This is because the gradient heating method in the melt blending and granulation stage of the present invention helps to optimize the microstructure of the composite material (such as crystallization behavior and molecular chain orientation). The isothermal treatment cannot achieve sufficient melting and shear dispersion of fillers and resins, resulting in defects inside the material and the inability to optimize the mechanical properties.

[0055] The bending strength and tensile strength of Comparative Example 6 decreased significantly. This is because the gradient temperature control in the preparation stage of FDM filament in the method of the present invention can effectively improve the compactness, uniformity and dimensional stability of the internal structure of medical-grade PEEK composite material, which helps to improve the interlayer bonding strength and mechanical properties of subsequent 3D printed products.

[0056] The foregoing description of specific exemplary embodiments of the invention is for illustrative and explanatory purposes. These descriptions are not intended to limit the invention to the precise forms disclosed, and it will be apparent that many changes and variations can be made in accordance with the foregoing teachings. The exemplary embodiments were chosen and described in order to explain the specific principles of the invention and its practical medical-grade PEEK composite materials, thereby enabling those skilled in the art to implement and utilize various different exemplary embodiments of the invention, as well as various different choices and variations. The scope of the invention is intended to be defined by the claims and their equivalents.

Claims

1. A medical-grade PEEK composite material for 3D printing, characterized in that, It is made from the following raw materials in parts by weight: 80-95 parts of polyetheretherketone matrix, 5-15 parts of bioactive filler, 0.5-5 parts of interface modifier, and 0.1-3 parts of thermal conductivity and nucleation enhancement agent; The bioactive filler comprises nano-hydroxyapatite and bioactive glass in a weight ratio of (1-5):(5-1).

2. The medical-grade PEEK composite material according to claim 1, characterized in that, The average particle size of the nano-hydroxyapatite is 30–100 nm, and the aspect ratio is greater than 5.

3. The medical-grade PEEK composite material according to claim 1, characterized in that, The bioactive glass has a particle size of 1–10 μm.

4. The medical-grade PEEK composite material according to claim 1, characterized in that, The interface modifier is a silane coupling agent or a titanate coupling agent.

5. The medical-grade PEEK composite material according to claim 1, characterized in that, The thermal conductivity and nucleation enhancer is nano-graphene; the nano-graphene is a nano-graphene sheet with surface functionalization through hydroxyl or carboxyl groups, and its specific surface area is 100-500 m² / g.

6. The medical-grade PEEK composite material according to claim 1, characterized in that, The bioactive filler also includes nano-titanium dioxide, which accounts for 1 to 5% of the total weight of the polyether ether ketone matrix.

7. The medical-grade PEEK composite material according to claim 1, characterized in that, The melt index of the polyetheretherketone matrix is ​​5 to 50 g / 10 min.

8. A method for preparing a medical-grade PEEK composite material for 3D printing as described in any one of claims 1 to 7, characterized in that, Includes the following steps: S1. Surface activation treatment of bioactive filler: Nano-hydroxyapatite and bioactive glass are dispersed in anhydrous ethanol, an interface modifier is added, and the mixture is ultrasonically stirred at 60-80℃ for 1-3 hours. Then, the mixture is filtered and dried to obtain surface-activated bioactive filler. S2. Premixing: Under the protection of nitrogen or argon atmosphere, the bioactive filler, polyether ether ketone matrix powder, and thermally conductive and nucleating enhancer from step S1 are mixed at a speed of 300-1000 r / min for 10-60 min to obtain a uniform premix. S3. Melt blending and granulation: The premixed material from step S2 is fed into a twin-screw extruder for melt blending, extrusion, cooling, traction and granulation, and then fed into a single-screw extruder for melt extrusion, cooling and shaping, traction and winding to produce FDM 3D printing filament, thus obtaining the medical-grade PEEK composite material.

9. The preparation method according to claim 8, characterized in that, In step S3, the processing temperature of the twin-screw extruder is: 290-300℃ in zone 1, 300-310℃ in zone 2, 310-320℃ in zone 3, 320-330℃ in zone 4, and 325-330℃ at the die head; the screw speed is 200-400 r / min.

10. The preparation method according to claim 8, characterized in that, In step S3, the processing temperature of the single-screw extruder is: 300-310℃ in zone 1, 310-320℃ in zone 2, 320-330℃ in zone 3, and 325-330℃ at the die head.

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