A polyetheretherketone (PEEK) based composite material, orthopedic implant, and preparation method thereof

Abstract

This invention belongs to the field of orthopedic implant materials, specifically disclosing a polyetheretherketone (PEEK) based composite material, an orthopedic implant, and a preparation method thereof. This application provides a PEEK based composite material prepared by secondary extrusion molding and multiple temperature ranges, along with its preparation method. It also discloses an orthopedic implant prepared based on this material and its preparation method. The PEEK based composite material provided in this application possesses excellent physical properties and biocompatibility. Orthopedic implants made from the PEEK based composite material not only have higher tensile strength and flexural strength but also superior biocompatibility.

Description

Technical Field

[0001] This invention belongs to the field of orthopedic implant materials, specifically relating to a polyether ether ketone-based composite material, an orthopedic implant, and a preparation method thereof. Background Technology

[0002] In recent years, with the continuous advancement of medical technology, orthopedic implant materials are no longer limited to metal, but are developing towards personalized and customized technologies. Customized orthopedic implants can meet the different needs of patients in specific situations, resulting in better actual treatment effects.

[0003] Polyetheretherketone (PEEK) possesses excellent biocompatibility, elastic modulus, and X-ray permeability, and is internationally considered one of the most promising next-generation biomaterials to replace titanium alloys as raw materials for bone implants. Therefore, personalized bone implant materials are currently a key research focus in orthopedic implant materials. However, PEEK is also a highly bioinert material. Soft tissues struggle to adhere and grow on the surface of pure PEEK, and bone tissue cannot integrate with it. This results in a barrier between soft tissue, bone tissue, and the PEEK bone implant, which is detrimental to patient recovery.

[0004] In existing technologies, numerous composite materials have been developed to address the problems associated with polyetheretherketone (PEEK). However, these existing PEEK composite materials still have shortcomings in their specific preparation and application methods. These shortcomings can lead to critical issues such as bioinertness and decreased mechanical properties between soft tissues and bone tissues. Therefore, it is of paramount importance to develop a PEEK composite orthopedic implant material and optimize its preparation and application methods to meet the urgent clinical demand for novel orthopedic implants. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a polyetheretherketone-based composite material, an orthopedic implant, and a preparation method thereof, specifically adopting the following technical solution:

[0006] On the one hand, this application discloses a method for preparing a polyetheretherketone-based composite material, including the following steps;

[0007] Polyetheretherketone (PEEK), hydroxyapatite, and carbon fiber were mixed to obtain material S101. Material S101 was then subjected to a first temperature-switched extrusion process. During this process, material S101 was extruded sequentially at temperatures A, B, C, D, E, and F. Temperature A was 325℃-370℃, temperature B was 335℃-380℃, temperature C was 345℃-375℃, temperature D was 360℃-395℃, temperature E was 360℃-410℃, and temperature F was 385℃-420℃. After the first temperature-switched extrusion process, material S102 was obtained.

[0008] Material S102 was subjected to a second temperature-switched extrusion process. In the second temperature-switched extrusion process, material S102 was extruded sequentially at temperatures G, H, I, J, K, and L. The temperatures for G were 360℃-385℃, H was 380℃-385℃, I was 380℃-395℃, J was 385℃-395℃, K was 395℃-405℃, and L was 95℃-105℃. After the second temperature-switched extrusion process, a polyether ether ketone (PEEK) based composite material was obtained.

[0009] Polyetheretherketone (PEEK) is a high-temperature thermoplastic specialty material with a glass transition temperature exceeding 140°C and a melting point exceeding 300°C. PEEK combines the heat resistance and chemical stability of aromatic thermosetting materials with the easy processing properties of thermoplastics, resulting in excellent overall performance. However, in existing technologies, PEEK-based composite materials often employ simple melting and cooling processes, leading to a failure to fully realize the high material properties of these composites.

[0010] This application provides a polyetheretherketone-based composite material prepared by two temperature-switched extrusion processes based on polyetheretherketone, hydroxyapatite, and carbon fiber. Unlike the prior art, this application prepares the polyetheretherketone-based composite material with superior performance by sequentially processing the raw materials at specific temperatures during the first and second temperature-switched extrusion processes.

[0011] In some preferred embodiments, polyetheretherketone, hydroxyapatite, and carbon fiber are subjected to a first vacuum drying at a temperature of 100℃-180℃ for 3-10 hours. After the first vacuum drying, they are mixed, and after mixing, a second vacuum drying is performed at a temperature of 100℃-120℃ for 10-12 hours. After the second vacuum drying, material S101 is obtained.

[0012] The polyether ether ketone (PEEK) based composite material provided in this application requires strict control of its moisture content to ensure stable and reliable quality during subsequent processing, thereby improving the performance of the PEEK based composite material provided in this application and ensuring a high yield rate.

[0013] In some preferred implementations, the mixing time is 24h-36h.

[0014] In some preferred embodiments, the hydroxyapatite material has a particle size of 15nm-60nm, and the carbon fibers have an average fiber diameter of 6μm-10μm and a length of 10μm-150μm.

[0015] The raw materials used in the polyetheretherketone (PEEK) based composite material provided in this application have specific requirements for the selection of added hydroxyapatite and carbon fiber. The addition of hydroxyapatite with a particle size of 15nm-60nm and carbon fibers with an average fiber diameter of 6μm-10μm and a length of 10μm-150μm can effectively improve the performance of the PEEK based composite material, and at the same time provide certain support for the structure and performance of the PEEK based composite material in the subsequent targeted two-stage temperature extrusion preparation process.

[0016] In some preferred embodiments, the equipment used for the first temperature-controlled extrusion is a twin-screw extruder, and the equipment used for the second temperature-controlled extrusion is a single-screw extruder. In the second temperature-controlled extrusion, the screw speed of the single-screw extruder is 15-45 r / min.

[0017] In this application, a twin-screw extruder is used as the production equipment in the first temperature-switched extrusion preparation process of the polyether ether ketone-based composite material, and a single-screw extruder is selected as the production equipment in the second temperature-switched extrusion preparation process. The reason why this application selects these two types of equipment as the technical solution is that these two types of equipment are common in actual production and have strong repeatability. However, in fact, the technical solution with functions provided in this application is not completely limited to these two types of equipment.

[0018] On the one hand, this application discloses a polyether ether ketone-based composite material prepared by the above preparation method.

[0019] In some preferred embodiments, the composition, by weight percentage, includes 75%-95% polyetheretherketone, 10%-15% hydroxyapatite, and 1%-10% carbon fiber.

[0020] In the polyetheretherketone-based composite material prepared by the above preparation method disclosed in this application, polyetheretherketone, hydroxyapatite and carbon fiber have more outstanding specific properties under this ratio. Therefore, in the subsequent embodiments of this application, the polyetheretherketone-based composite material is prepared based on a mass percentage of 75%-95% polyetheretherketone, 10%-15% hydroxyapatite and 1%-10% carbon fiber.

[0021] This application also discloses an orthopedic implant made from the above-mentioned polyether ether ketone-based composite material.

[0022] This application also discloses a method for preparing an orthopedic implant based on the above-mentioned polyether ether ketone-based composite material, comprising the following steps:

[0023] Orthopedic implants were obtained by fused deposition modeling using polyetheretherketone (PEEK) based composite materials.

[0024] In some preferred embodiments, fused deposition printing includes the following steps: placing the polyetheretherketone (PEEK) composite material in a fused deposition 3D printer and performing fused deposition printing, wherein the printing conditions include: nozzle temperature of 400℃-420℃, printing ambient temperature of 95℃-115℃, printing platform temperature of 90℃-105℃, printing speed of 10mm / s-30mm / s, and printing layer thickness of 0.1mm-0.2mm.

[0025] During theoretical research and experimental exploration, the inventors of this application discovered that in the process of preparing polyether ether ketone-based composite materials, each heating zone of the twin-screw extruder and single-screw extruder used will have a significant impact on the final properties of the polyether ether ketone-based composite material; each temperature parameter in each processing stage of the polyether ether ketone-based composite material will have unpredictable effects on many aspects such as the material's flowability, molecular chain segment relaxation, crystallinity, grain size and distribution.

[0026] Therefore, the inventors conducted extensive research on precise temperature control during the processing to determine the most suitable processing temperature for the polyether ether ketone (PEEK) composite material provided in this application for the preparation of orthopedic implants. Specifically, if the material used to process the PEEK composite material is processed at a lower temperature during isothermal processing, its low fluidity can easily cause difficulties in material transport, leading to equipment jamming and resulting in poor material quality that cannot be further processed and used. If a higher isothermal temperature is used throughout the preparation process, the mechanical strength and stability of the material will be poor, resulting in a final material with low strength that fails to meet performance requirements. The various temperature stages distinguished during the variable-temperature preparation process are also of great significance. The preheating stage requires precise temperature control to ensure the material is continuously fed into the subsequent melting stage in a suitable softened state. Lower temperatures can lead to discontinuous material input, while higher temperatures may cause blockages due to excessive material flow. During the melting stage, it's crucial to avoid incomplete melting at low temperatures, which could reduce material uniformity during processing, and to prevent thermal decomposition of the material at high temperatures. Immediately following the melting stage is the extrusion stage. The purpose of this stage is to ensure smooth shaping of the material before extrusion, promote crystallization, and guarantee the material's mechanical strength and stability. Therefore, excessively high or low temperatures during this stage can lead to irreversible defects in the final product's performance.

[0027] This application optimizes the polyetheretherketone (PEEK) composite material for fused deposition modeling (FDM) by precisely controlling the temperature during its preparation. This results in a PEEK composite material more suitable for FDM 3D printing. The variable-temperature extrusion process allows for a tighter integration of the PEEK composite material with hydroxyapatite and carbon fibers at the microscale. Furthermore, the precise temperature control defines a specific processing window for the PEEK composite material, leading to superior mechanical properties and enabling the production of high-performance orthopedic implants using specific FDM 3D printing conditions.

[0028] The beneficial effects of this application are as follows: the polyether ether ketone-based composite material provided by this application has excellent physical properties and biocompatibility. Orthopedic implants made based on the polyether ether ketone-based composite material provided by this application not only have stronger tensile strength and flexural strength, but also have better biocompatibility. Attached Figure Description

[0029] Figure 1 The image shown is an electron microscope photograph of an orthopedic implant made of polyetheretherketone-based composite material according to a specific embodiment of this application. Detailed Implementation

[0030] The following will provide a clear and complete description of the concept and technical effects of the present invention in conjunction with the embodiments and accompanying drawings, so as to fully understand the purpose, solution and effects of the present invention. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of the present invention can be combined with each other.

[0031] Example

[0032] A polyetheretherketone-based composite material, the preparation method of which includes the following steps:

[0033] First, the raw materials are prepared according to the following mass ratio: 80% polyetheretherketone particles, 15% hydroxyapatite, and 5% carbon fiber. The prepared raw materials are placed in a vacuum drying oven at 100°C and dried for 12 hours. After drying, they are sent to a V-type mixer for mixing and stirring for 24 hours. Agate balls are used as the stirring medium during the mixing process. After the mixing is completed, the mixed composite material is placed in a vacuum drying oven at 110°C and dried for 12 hours for a second vacuum drying. After the second vacuum drying, material S101 is obtained.

[0034] Material S101 is added to the barrel of a twin-screw extruder. The six temperature zones of the twin-screw extruder, namely temperature A, temperature B, temperature C, temperature D, temperature E and temperature F, are set to 365℃, 375℃, 375℃, 390℃, 400℃ and 410℃ respectively. Material S101 undergoes a first temperature-variable extrusion at the above six temperatures in sequence, and the product is prepared into granules by an air-cooling device and a granulator. These granules are material S102.

[0035] Material S102 is added to a single-screw extruder for a second temperature-switched extrusion. The single screw speed is 30 r / min. The six temperature zones of the single-screw extruder, namely temperature G, temperature H, temperature I, temperature J, temperature K and temperature L, are set to 370℃, 380℃, 395℃, 395℃, 405℃ and 100℃ respectively. Material S102 is subjected to the above six temperatures for the second temperature-switched extrusion. The material obtained after the temperature-switched extrusion is the polyether ether ketone-based composite material.

[0036] In this embodiment, the polyetheretherketone-based composite material is wound into shape after final extrusion to form a 3D printing filament with a diameter of 1.75±0.05mm.

[0037] An orthopedic implant, the preparation method of which includes the following steps:

[0038] The polyetheretherketone (PEEK) composite filaments prepared above were placed in a fused deposition modeling (FDM) 3D printer. The 3D model file of the orthopedic implant was imported into the printer's control system for FDM printing. The printing parameters were: nozzle temperature 405℃, ambient temperature 100℃, printing platform temperature 105℃, printing speed 20mm / s, and layer thickness 0.2mm. After printing, excess supports were removed, the sample surface was smoothed, and sandblasted to obtain the finished product, which is the orthopedic implant.

[0039] Comparative Example

[0040] An orthopedic implant, the preparation method of which includes the following steps:

[0041] Pure polyetheretherketone (PEEK) filaments were placed in a fused deposition modeling (FDM) 3D printer. The printer's control system imported a 3D model file of the orthopedic implant, and FDM printing was performed. The printing parameters were: nozzle temperature 405℃, ambient temperature 100℃, printing platform temperature 105℃, printing speed 20mm / s, and layer thickness 0.2mm. After printing, excess supports were removed, the sample surface was smoothed, and sandblasted to obtain the finished product, the orthopedic implant.

[0042] Performance Testing and Results Discussion

[0043] The melt flow index (MFR) of the polyether ether ketone-based composite filaments prepared in the examples was tested at different temperatures, and the results are shown in Table 1.

[0044] The tensile and flexural properties of the orthopedic implants prepared in the examples and comparative examples were tested, and the results are shown in Table 2.

[0045] Osteoblastic progenitor cells MC3T3-E1 were used to perform cell proliferation culture experiments on orthopedic implant sample materials prepared in the examples and comparative examples. The optical density (OD) value of the cells was detected on days 1, 3, 5 and 7 of culture. The results are shown in Table 3.

[0046] Scanning electron microscopy analysis was performed on the cross-sections of the orthopedic implants prepared in the examples, and the results are shown in [Figure number missing]. Figure 1 .

[0047] Table 1

[0048]

[0049] Melt flow index (MFR) is commonly used as a parameter for quality control of thermoplastic resins and for thermoplastic molding process conditions. Since polyetheretherketone (PEEK) composites can be considered thermoplastic resins, their flowability is closely related to their service temperature. Table 1 shows that as the temperature increases, the MFR value of the filaments prepared from the PEEK composites first increases and then decreases, with the highest MFR (21.542 g / 10min) observed at 410℃. This indicates that the melt flowability of the PEEK composite is best at this temperature. Therefore, in the selection of the temperature for the first temperature-variable extrusion, the final temperature was set to 410℃. At this temperature, the PEEK composite melt is most fully melted, resulting in a PEEK composite with optimal flowability, facilitating the subsequent second temperature-variable extrusion.

[0050] Table 2

[0051]

[0052] As shown in Table 2, the tensile strength and flexural strength of the examples are higher than those of the comparative examples, indicating that the mechanical properties of the polyether ether ketone-based composite material prepared by the present invention are enhanced. Analysis suggests that the use of a two-stage temperature-variable extrusion process in the technical solution provided in this application has a positive effect on the rheological properties of the polyether ether ketone-based composite material during processing, resulting in superior steady-state torque performance and thus, more outstanding tensile and flexural strength.

[0053] Table 3

[0054]

[0055] As shown in Table 3, the cell proliferation effect of the sample in the example is better than that of the comparative example, reflecting the excellent biocompatibility of the polyether ether ketone-based composite material prepared by the present invention.

[0056] Based on the above data, it can be concluded that the orthopedic implants prepared by the polyetheretherketone-based composite material provided in this application in conjunction with the orthopedic implant preparation method provided in this application have excellent tensile strength and biocompatibility.

[0057] Although the description of the invention has been quite detailed and particularly of several described embodiments, it is not intended to limit it to any of these details or embodiments or any particular embodiment, but should be considered as providing a broad possible interpretation of the claims by referring to the appended claims and taking into account the prior art, thereby effectively covering the intended scope of the invention. Furthermore, the invention has been described above with respect to embodiments foreseeable by the inventors in order to provide a useful description, and non-substantial modifications to the invention that have not yet been foreseen may still represent equivalent modifications.

Claims

1. A method for preparing a polyetheretherketone-based composite material, characterized in that, Includes the following steps; Polyetheretherketone (PEEK), hydroxyapatite, and carbon fiber are mixed to obtain material S101. Material S101 is then subjected to a first temperature-switched extrusion process. During this first temperature-switched extrusion process, material S101 is extruded sequentially at temperatures A, B, C, D, E, and F. Temperature A is 325℃-370℃, temperature B is 335℃-380℃, temperature C is 345℃-375℃, temperature D is 360℃-395℃, temperature E is 360℃-410℃, and temperature F is 385℃-420℃. After completing the first temperature-switched extrusion process, material S102 is obtained. The material S102 is prepared by a second temperature-switched extrusion process. In this second temperature-switched extrusion process, the material S102 is extruded sequentially at temperatures G, H, I, J, K, and L. The temperatures G, H, I, J, K, and L are 360℃-385℃, 380℃-385℃, 380℃-395℃, 385℃-395℃, 395℃-405℃, and 95℃-105℃. After the second temperature-switched extrusion process, the polyetheretherketone (PEEK) based composite material is obtained. The hydroxyapatite material has a particle size of 15nm-60nm, and the carbon fiber has an average fiber diameter of 6μm-10μm and a length of 10μm-150μm. The equipment used in the first temperature-controlled extrusion process is a twin-screw extruder, and the equipment used in the second temperature-controlled extrusion process is a single-screw extruder with a screw speed of 15 r / min - 45 r / min.

2. The method for preparing a polyetheretherketone-based composite material according to claim 1, characterized in that, Polyetheretherketone, hydroxyapatite, and carbon fiber are subjected to a first vacuum drying at a temperature of 100℃-180℃ for 3-12 hours. After the first vacuum drying, they are mixed and subjected to a second vacuum drying at a temperature of 100℃-120℃ for 10-12 hours. After the second vacuum drying, material S101 is obtained.

3. The method for preparing a polyetheretherketone-based composite material according to claim 1, characterized in that, The mixing time is 24h-36h.

4. A polyetheretherketone-based composite material, characterized in that, It is prepared by the preparation method according to any one of claims 1-3.

5. A polyetheretherketone-based composite material according to claim 4, characterized in that, The polyetheretherketone-based composite material comprises, by mass percentage: 75%-95% polyetheretherketone, 10%-15% hydroxyapatite, and 1%-10% carbon fiber.

6. An orthopedic implant, characterized in that, Including the polyetheretherketone-based composite material as described in claim 4 or 5.

7. A method for preparing an orthopedic implant, characterized in that, Includes the following steps: The orthopedic implant is obtained by fused deposition printing of the polyether ether ketone-based composite material according to claim 4 or 5.

8. The method for preparing an orthopedic implant according to claim 7, characterized in that, The fused deposition modeling (FDM) printing includes the following steps: placing the polyether ether ketone (PEEK)-based composite material in a fused deposition modeling 3D printer for fused deposition modeling printing, wherein the printing conditions include: nozzle temperature of 400℃-420℃, printing ambient temperature of 95℃-115℃, printing platform temperature of 90℃-105℃, printing speed of 10mm / s-30mm / s, and printing layer thickness of 0.1mm-0.2mm.

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