Dual-network polyether-ether-ketone composite material as well as preparation method and application thereof

Abstract

The invention discloses a polyether-ether-ketone composite material with a double-network structure and a preparation method of the polyether-ether-ketone composite material. The composite material comprises a matrix component, a rigid network component, an interface compatibilization component and a function synergistic component, the material is specifically prepared from polyether-ether-ketone resin, a thermotropic liquid crystal polymer, surface functionalized boron nitride nanofibers, silane coupling agent modified nano titanium dioxide whiskers, maleic anhydride grafted SEBS, polyetherimide, molybdenum disulfide / carbon nanotube hybrid filler, polytetrafluoroethylene micro powder and nano hydroxyapatite according to a specific ratio. The preparation method mainly comprises the following steps: carrying out surface functionalization treatment on the nanofiller; dispersing the components in a polyetheretherketone concentrated sulfuric acid solution to form structured slurry; carrying out wet precipitation and two-way stretching to obtain a pre-oriented gel blank; and finally, mixing with functional synergistic components, and carrying out hot press molding. According to the method, a unique dual-network reinforced structure is constructed, the interface compatibility and dispersity of all the components are effectively improved, and the prepared composite material is excellent in comprehensive performance.

Description

Technical Field

[0001] This invention relates to the field of polymer composite materials technology, and in particular to a polyetheretherketone composite material with a dual network structure, its preparation method, and its application. Background Technology

[0002] Polyetheretherketone (PEEK), a high-performance specialty engineering plastic, possesses excellent mechanical properties, heat resistance (glass transition temperature approximately 143°C, melting point approximately 343°C), and chemical stability, making it widely used in aerospace, medical devices, and the electronics industry. However, pure PEEK materials have the following inherent drawbacks: 1. Its wear resistance is poor, with a friction coefficient typically between 0.3 and 0.4, which limits its application in friction components such as bearings and gears; 2. Insufficient toughness; the notched impact strength is generally 50-60 J / m, making it prone to brittle fracture under impact load. 3. Poor thermal conductivity, with a thermal conductivity coefficient of approximately 0.25 W / (m·K), which is not conducive to the dissipation of frictional heat and heat from electronic components; 4. It has strong biological inertness and limited ability to integrate with bone tissue, which affects its application effect in orthopedic implants.

[0003] Existing improvement technologies, such as CN112280245A which discloses carbon fiber reinforced PEEK composites, improve stiffness and strength, but reduce impact toughness by about 20%, and their biocompatibility with human tissue remains unsatisfactory. US20180201562A1 uses graphite and MoS2 blends to improve wear resistance, but the material's strength and bioactivity are not simultaneously improved. These single modification methods are insufficient to achieve synergistic optimization of the material's overall performance. Summary of the Invention

[0004] The present invention aims to provide a dual-network structure polyetheretherketone composite material. Another objective of the present invention is to provide a method for preparing the above-mentioned composite material. Yet another objective of the present invention is to illustrate the application of this composite material in several high-requirement fields such as artificial joints, aerospace bearings, and electronic heat sinks.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: The composite material is characterized by comprising the following components by mass percentage, the sum of which is 100%: Matrix components: 55-75% polyetheretherketone (PEEK) resin and 5-15% thermotropic liquid crystal polymer (TLCP). The addition of TLCP can form microfibers during processing, forming a preliminary composite network with the PEEK matrix.

[0006] Rigid network components: 3-8% surface-functionalized boron nitride nanofibers (BNNF) and 2-7% silane coupling agent-modified nano-titanium dioxide (TiO2) whiskers. These one-dimensional / whisker-like nanomaterials, after surface functionalization, are aligned and overlapped during processing to form a rigid three-dimensional reinforcing network that runs through the material.

[0007] Interface compatibilizing components: 3-8% maleic anhydride-grafted styrene-ethylene-butadiene-styrene block copolymer (SEBS-g-MAH) and 2-5% polyetherimide (PEI). This compound system can significantly improve the interfacial compatibility and adhesion between inorganic rigid fillers and organic polymer matrices, achieve effective stress transfer, and enhance matrix toughness.

[0008] Synergistic functional components: 1-3% molybdenum disulfide / carbon nanotube hybrid filler (MoS2 / CNT), 2-4% polytetrafluoroethylene (PTFE) micropowder, and 1-5% nano-hydroxyapatite (nHA). These components mainly contribute to friction lubrication, thermal conductivity, and bioactivity, respectively, and there is a synergistic effect among them.

[0009] Preferably, the surface-functionalized boron nitride nanofibers have a diameter of 50-200 nm and an aspect ratio of 20-50. Their surfaces are grafted with hydroxyl and carboxyl groups through acid treatment, and the surface hydroxyl density is not less than 3 per nm².

[0010] Preferably, the silane coupling agent modified nano-TiO2 whiskers are treated with γ-aminopropyltriethoxysilane (KH-550) or the like.

[0011] Preferably, in the interface compatibilizer, the mass ratio of SEBS-g-MAH to PEI is 2:1 to 1:1.

[0012] Preferably, the molybdenum disulfide and multi-walled carbon nanotubes are pre-constructed into a core-shell or entangled hybrid filler by hydrothermal or vapor deposition methods at a mass ratio of 1:1 to 1:2.

[0013] A method for preparing a dual-network polyetheretherketone composite material, the method comprising the following steps: (1) Surface functionalization treatment: Boron nitride nanofibers were placed in a mixture of concentrated sulfuric acid and concentrated nitric acid with a volume ratio of 3:1 and refluxed at 80°C for 2 hours. After cooling, washing and drying, functionalized BNNF with hydroxyl and carboxyl groups on the surface was obtained. Nano TiO2 whiskers were dispersed in an ethanol solution, and silane coupling agent KH-550 was added. The mixture was stirred at 75°C for 4 hours. After filtration, washing and drying, aminated TiO2 whiskers were obtained.

[0014] (2) Preparation of dual-network slurry: A measured amount of PEEK resin was dissolved in concentrated sulfuric acid to prepare a homogeneous solution with a mass fraction of approximately 20%. Under stirring, the functionalized BNNF, modified TiO2 whiskers, TLCP particles, and all the amounts of SEBS-g-MAH and PEI obtained in step (1) were added sequentially to the above PEEK sulfuric acid solution. The mixture was transferred to a high-speed shear emulsifier and strongly dispersed at a speed of 8000 rpm for 30 minutes to form a uniform and stable "dual-network" structured slurry. Among them, TLCP and nanofillers were initially dispersed under shear force and may have pre-oriented.

[0015] (3) In-situ stretching: The above slurry is injected into a large amount of deionized water at a uniform speed. PEEK and its composite material precipitate out and form a gel solid due to the sharp decrease in solubility. Before the gel material is completely solidified and shaped, it is immediately subjected to biaxial stretching in a specific device. The stretching temperature is controlled at 80-120℃, and the longitudinal and transverse stretching ratios are controlled at 3:1 (ranging from 2:1 to 4:1). The stretching rate is 10 mm / min. This process forces the TLCP molecular chains, BNNF and TiO2 whiskers to be highly oriented along the stretching direction, forming an ordered three-dimensional reinforcing skeleton "frozen" inside the material. The stretched material is thoroughly washed until neutral and then dried to obtain a composite material blank with a pre-oriented structure.

[0016] (4) Hot pressing: The dried blank is uniformly mixed with the remaining functional synergistic components (MoS2 / CNT hybrid filler, PTFE micro powder and nHA) in a high-speed mixer; the mixed material is placed in a hot press mold and hot-pressed at 385℃ and 35 MPa, and held at this temperature and pressure for 90 minutes to allow the material to fully melt, plasticize and finally solidify; after hot pressing, the temperature is controlled by a program and cooled at a slow rate of 1-3℃ / min (preferably 2℃ / min) to below 200℃, and then naturally cooled to room temperature. This slow cooling process helps to eliminate internal stress and improve the crystal structure of PEEK, thereby stabilizing the material properties.

[0017] The beneficial effects of this invention are as follows: 1. This invention is the first to construct a dual interpenetrating network structure in PEEK composites, in which an "oriented inorganic nanofiber / whisker rigid network" and a "PEEK / TLCP organic matrix flexible network" interpenetrate and synergistically interact. This structure achieves optimized integration of the reinforcing phase and the matrix at the nano and micro scales; 2. This invention achieves innovative multi-component synergistic effects. Firstly, there is mechanical synergy: oriented BNNF and TiO2 whiskers provide high-strength and high-modulus rigid support, while SEBS-g-MAH and PEI inhibit crack propagation through compatibilization and toughening mechanisms. This results in a composite material with a tensile strength ≥120 MPa and a notched impact strength increased by more than 40% (≥85 J / m). Secondly, there is tribological synergy: PTFE acts as a solid lubricant, providing a continuous lubricating film, while the MoS2 / CNT hybrid filler forms a stable transfer film at the friction interface and enhances its adhesion. The synergy of these two components significantly reduces the coefficient of friction of the composite material to 0.15-0.20 and the wear rate to ≤2.5×10⁻⁻⁻⁶. 6 The third aspect is the synergistic effect of thermal management. The highly thermally conductive BNNF and CNT form an efficient three-dimensional thermal conduction pathway in the matrix through orientational arrangement, which increases the thermal conductivity of the composite material to 1.8-2.2 W / (m·K), which is nearly an order of magnitude higher than that of pure PEEK. Finally, there is the synergistic effect of biological function. nHA provides biomineralization active sites, and TiO2 whiskers also have certain biological activity after surface modification. Together, they promote osteoblast adhesion, proliferation and the formation of bone-like apatite layer, and the cell proliferation rate can be increased by 50%. 3. A unique step-by-step process combining "solution blending - in-situ gel stretching - melt hot pressing" has been developed. Solution blending ensures the initial uniform dispersion of the nanofiller; in-situ biaxial stretching in the gel state is key to achieving high orientation of the filler and TLCP and forming a double network structure; subsequent melt hot pressing solidifies the structure and introduces other functional components. This process improves the reinforcement / toughening efficiency of the filler by approximately 35% compared to conventional melt blending methods. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the microstructure of the dual-network polyetheretherketone composite material of the present invention.

[0019] Figure 2 This is a flowchart illustrating the preparation process of the dual-network polyetheretherketone composite material of the present invention.

[0020] Figure 3 This is a bar chart comparing the tensile strength of Examples 1-3 and Comparative Examples 1-6 of the present invention.

[0021] Figure 4 This is a bar chart comparing the notched impact strength of Examples 1-3 and Comparative Examples 1-6 of the present invention.

[0022] Figure 5 This is a bar chart comparing the friction coefficients of Examples 1-3 and Comparative Examples 1-6 of the present invention.

[0023] Figure 6 This is a bar chart comparing the notch thermal conductivity of Embodiments 1-3 and Comparative Examples 1-6 of the present invention.

[0024] Figure 7 This is a bar chart comparing the wear rates of Examples 1-3 and Comparative Examples 1-6 of the present invention.

[0025] Figure 8 Line graphs showing the comparison of cell proliferation rates in Examples 1-3 and Comparative Examples 1-6 of this invention. Detailed Implementation

[0026] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Example 1

[0027] A dual-network structure polyetheretherketone composite material, the composition of which by mass percentage is: 65% polyetheretherketone resin, 10% thermotropic liquid crystal polymer; 5.5% surface-functionalized boron nitride nanofibers (diameter 100-150 nm, aspect ratio 20-50, surface hydroxyl density approximately 3.5 hydroxyl groups / nm²), 4.5% silane coupling agent modified nano-titanium dioxide whiskers; 5.5% maleic anhydride-grafted styrene-ethylene-butadiene-styrene block copolymer (SEBS-g-MAH to PEI mass ratio 1.5:1), 3.7% polyetherimide; 2% molybdenum disulfide / carbon nanotube hybrid filler (MoS2:CNT=1:1.5, core-shell structure), 3% polytetrafluoroethylene micropowder, and 3% nano-hydroxyapatite.

[0028] Its preparation method includes the following steps: 1. Surface functionalization treatment: Treat BNNF and TiO2 whiskers according to the instructions.

[0029] 2. Preparation of Dual-Network Slurry: Dissolve 65g of PEEK in 260g of concentrated sulfuric acid to prepare a 20% solution. Under stirring, add the treated BNNF, TiO2 whiskers, TLCP particles, SEBS-g-MAH, and PEI sequentially. Place the mixture in a high-speed shear emulsifier and disperse at 8000 rpm for 30 minutes to obtain a homogeneous slurry.

[0030] 3. In-situ stretching: The slurry is injected uniformly into a large amount of deionized water, causing gelation. The gel is then subjected to biaxial stretching at 100°C, with a longitudinal to transverse stretching ratio of 3:1 and a speed of 10 mm / min. After stretching, the material is washed and dried to obtain the preform.

[0031] 4. Hot pressing: The blank is mixed with MoS2 / CNT, PTFE micro powder, and nHA at high speed until homogeneous. The mixture is placed in a hot press mold at 385℃ and 35 MPa and held under pressure for 90 minutes. Then, the temperature is reduced to below 200℃ at a rate of 2℃ / min, and then allowed to cool naturally to room temperature to obtain the composite material sheet. Example 2

[0032] A dual-network structure polyetheretherketone composite material, the composition of which by mass percentage is: 72% polyetheretherketone resin, 8% thermotropic liquid crystal polymer; 3% surface-functionalized boron nitride nanofibers (diameter 100-150 nm, aspect ratio 20-50, surface hydroxyl density approximately 3.5 hydroxyl groups / nm²), 2% silane coupling agent modified nano-titanium dioxide whiskers; 4% maleic anhydride-grafted styrene-ethylene-butadiene-styrene block copolymer (SEBS-g-MAH to PEI mass ratio 2:1), 2% polyetherimide; 1% molybdenum disulfide / carbon nanotube hybrid filler (MoS2:CNT=1:1.5, core-shell structure), 4% polytetrafluoroethylene micropowder, and 5% nano-hydroxyapatite.

[0033] Its preparation method includes the following steps: 1. Surface functionalization treatment: Treat BNNF and TiO2 whiskers according to the instructions.

[0034] 2. Preparation of Dual-Network Slurry: Dissolve 65g of PEEK in 260g of concentrated sulfuric acid to prepare a 20% solution. Under stirring, add the treated BNNF, TiO2 whiskers, TLCP particles, SEBS-g-MAH, and PEI sequentially. Place the mixture in a high-speed shear emulsifier and disperse at 8000 rpm for 30 minutes to obtain a homogeneous slurry.

[0035] 3. In-situ stretching: The slurry is injected uniformly into a large amount of deionized water, causing gelation. The gel is then subjected to biaxial stretching at 100°C, with a longitudinal to transverse stretching ratio of 2.5:1 and a speed of 10 mm / min. After stretching, the material is washed and dried to obtain the preform.

[0036] 4. Hot pressing: The blank is mixed uniformly with MoS2 / CNT, PTFE micro powder, and nHA at high speed. The mixture is placed in a hot press mold at 385℃ and 35 MPa and held under pressure for 90 minutes. Then, the temperature is reduced to below 200℃ at a rate of 2℃ / min, and then allowed to cool naturally to room temperature to obtain the composite material sheet. Example 3

[0037] A dual-network structure polyetheretherketone composite material, the composition of which by mass percentage is: 58% polyetheretherketone resin, 14% thermotropic liquid crystal polymer; 8% surface-functionalized boron nitride nanofibers (diameter 100-150 nm, aspect ratio 20-50, surface hydroxyl density approximately 3.5 hydroxyl groups / nm²), 7% silane coupling agent modified nano-titanium dioxide whiskers; 4.5% maleic anhydride-grafted styrene-ethylene-butadiene-styrene block copolymer (SEBS-g-MAH to PEI mass ratio 1:1), 4.5% polyetherimide; 2.5% molybdenum disulfide / carbon nanotube hybrid filler (MoS2:CNT=1:1.5, core-shell structure), 2% polytetrafluoroethylene micropowder, and 3% nano-hydroxyapatite.

[0038] Its preparation method includes the following steps: 1. Surface functionalization treatment: Treat BNNF and TiO2 whiskers according to the instructions.

[0039] 2. Preparation of Dual-Network Slurry: Dissolve 65g of PEEK in 260g of concentrated sulfuric acid to prepare a 20% solution. Under stirring, add the treated BNNF, TiO2 whiskers, TLCP particles, SEBS-g-MAH, and PEI sequentially. Place the mixture in a high-speed shear emulsifier and disperse at 8000 rpm for 30 minutes to obtain a homogeneous slurry.

[0040] 3. In-situ stretching: The slurry is injected uniformly into a large amount of deionized water, causing gelation. The gel is then subjected to biaxial stretching at 100°C, with a longitudinal to transverse stretching ratio of 3.5:1 and a speed of 10 mm / min. After stretching, the material is washed and dried to obtain the preform.

[0041] 4. Hot pressing: The blank is mixed with MoS2 / CNT, PTFE micro powder, and nHA at high speed until homogeneous. The mixture is placed in a hot press mold at 385℃ and 35 MPa and held under pressure for 90 minutes. Then, the temperature is reduced to below 200℃ at a rate of 2℃ / min, and then allowed to cool naturally to room temperature to obtain the composite material sheet. Comparative Example 1

[0042] Same as Example 1, except that the "in-situ stretching molding" step is omitted. Specifically: after preparing the slurry in step (2) and injecting deionized water to precipitate, washing and drying, the biaxial stretching is not performed. Instead, the obtained unoriented powder is directly mixed with the functional synergistic component and hot-pressed in step (4). Comparative Example 2

[0043] Same as Example 1, except that all interfacial compatibilizing components (SEBS-g-MAH and PEI) are removed and their mass is added to the PEEK resin in an equal proportion (i.e., the mass fraction of PEEK becomes 74.2%). Comparative Example 3

[0044] Same as Example 1, except that only a single rigid filler is used. Specifically, the silane coupling agent-modified nano-TiO2 whiskers are removed and their mass is added to the surface-functionalized BNNF (i.e., the mass fraction of BNNF becomes 10%). Comparative Example 4

[0045] Same as Example 1, except that only a single lubricating filler is used. Specifically, the PTFE micro powder is removed and its mass is added to the MoS2 / CNT hybrid filler (i.e., the mass fraction of MoS2 / CNT becomes 5%). Comparative Example 5

[0046] Same as Example 1, except that BNNF and TiO2 whiskers are not subjected to any surface treatment, and raw BNNF nanofibers and unmodified TiO2 whiskers are used directly. Comparative Example 6

[0047] Similar to Example 1, the difference lies in the use of the most conventional single-screw melt-blending, granulation, and hot-pressing molding process. Specifically, all components (including all fillers) are added to a high-speed mixer for premixing at once, then melt-blended and granulated at 380-390°C using a twin-screw extruder, and finally the granules are hot-pressed at 385°C and 35 MPa for 90 minutes to form the final product.

[0048] The detailed data results are shown in the table below: Project Specifications Tensile strength (MPa) Notched impact strength (J / m) Coefficient of friction (vs. GCr15 steel ball) <![CDATA[Wear rate (10⁻ 6 mm³ / (N·m))]]> Thermal conductivity (W / (m·K)) Cell proliferation rate (vs. pure PEEK, %) Pure PEEK 95 60 0.35-0.40 ~12.0 0.25 100 Example 1 128 92 0.17 2.1 2.05 152 Example 2 118 88 0.19 2.4 1.85 160 Example 3 135 86 0.18 2.3 2.18 148 Comparative Example 1 105 72 0.25 5.8 1.20 130 Comparative Example 2 110 65 0.21 4.5 1.95 145 Comparative Example 3 122 84 0.18 2.5 1.70 140 Comparative Example 4 125 90 0.22 3.8 2.10 150 Comparative Example 5 98 68 0.24 6.5 0.90 125 Comparative Example 6 108 70 0.28 7.2 1.05 135 Experimental Results: Example 1 exhibited the best overall performance, surpassing pure PEEK in all aspects. The properties of Comparative Example 1 (without stretching) and Comparative Example 6 (conventional melt blending), especially mechanical, frictional, and thermal conductivity, were significantly lower than those of Example 1. This demonstrates that the "solution blending-in-situ gel stretching-melt hot pressing" process is crucial for constructing an oriented dual-network structure and achieving efficient filler reinforcement (such as an order-of-magnitude increase in thermal conductivity), validating the approximately 35% increase in reinforcement efficiency brought about by process innovation. Example 1 showed the best tensile and impact strength. Comparative Example 2 (without interfacial compatibilizer) showed a sharp drop in impact strength, indicating the key role of SEBS-g-MAH / PEI in toughening and stress transfer. Comparative Example 5 (without surface treatment) had the worst mechanical properties, confirming that filler surface functionalization is fundamental to improving interfacial adhesion. The tensile strength and thermal conductivity of Example 1 were higher than those of Comparative Example 3 (single BNNF), indicating a complementary synergistic effect in shape and size between BNNF and TiO2 whiskers when forming a rigid thermally conductive network. Example 1 had the lowest coefficient of friction and wear rate. The deterioration in tribological properties of Comparative Example 4 (single lubricating filler) demonstrates the synergistic effect of PTFE and MoS2 / CNT in forming a continuous lubricating film and stabilizing the transfer film. All samples containing nHA and modified TiO2 (Examples 1-3) showed significantly increased cell proliferation rates, validating the synergistic bioactivity. In summary, this invention, through a specific multi-component system design and a stepwise process of "solution blending-in-situ gel stretching-melt hot pressing," successfully constructed a dual-network structure, achieving multiple synergistic improvements in mechanical, tribological, thermal conductivity, and biological functions. The comparative results fully and powerfully demonstrate the inventiveness, novelty, and technical effectiveness of this invention.

[0049] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. A dual-network structure polyetheretherketone composite material, characterized in that, The components comprised of the following mass percentages, where the sum of the mass percentages of each component is 100%: Matrix components: 55-75% polyetheretherketone resin and 5-15% thermotropic liquid crystal polymer; Rigid network components: 3-8% surface-functionalized boron nitride nanofibers and 2-7% silane coupling agent modified nano-titanium dioxide whiskers; Interface compatibilizing components: 3-8% maleic anhydride-grafted styrene-ethylene-butadiene-styrene block copolymer and 2-5% polyetherimide; Functional synergistic components: 1-3% molybdenum disulfide / carbon nanotube hybrid filler, 2-4% polytetrafluoroethylene micro powder and 1-5% nano-hydroxyapatite.

2. The dual-network structure polyetheretherketone composite material according to claim 1, characterized in that, The surface-functionalized boron nitride nanofibers have a diameter of 50-200 nm and an aspect ratio of 20-50. Their surfaces are grafted with hydroxyl and carboxyl groups through acid treatment, and the surface hydroxyl density is not less than 3 per nm². The silane coupling agent modified nano-titanium dioxide whiskers are surface-treated with γ-aminopropyltriethoxysilane.

3. The dual-network structure polyetheretherketone composite material according to claim 1, characterized in that, In the interface compatibilizing component, the mass ratio of maleic anhydride-grafted styrene-ethylene-butadiene-styrene block copolymer to polyetherimide is 2:1 to 1:

1.

4. The dual-network structure polyetheretherketone composite material according to claim 1, characterized in that, In the molybdenum disulfide / carbon nanotube hybrid filler, molybdenum disulfide and multi-walled carbon nanotubes are pre-constructed into a core-shell or entangled structure by hydrothermal method or vapor deposition method at a mass ratio of 1:1 to 1:

2.

5. A method for preparing a dual-network structure polyetheretherketone composite material as described in any one of claims 1-4, characterized in that, Includes the following steps: (1) Surface functionalization treatment: boron nitride nanofibers were acidified to obtain surface functionalized boron nitride nanofibers; nano titanium dioxide whiskers were treated with silane coupling agent to obtain modified nano titanium dioxide whiskers. (2) Preparation of dual-network slurry: Polyetheretherketone resin was dissolved in concentrated sulfuric acid to prepare a homogeneous solution; Under stirring, the surface-functionalized boron nitride nanofibers, modified nano-titanium dioxide whiskers, thermotropic liquid crystal polymer particles, and the full amount of maleic anhydride-grafted styrene-ethylene-butadiene-styrene block copolymer and polyetherimide obtained in step (1) are sequentially added to the polyether ether ketone sulfuric acid solution; high-speed shear dispersion is carried out to form a uniform and stable structured slurry. (3) In-situ stretching: The slurry obtained in step (2) is injected into deionized water and precipitates to form a gel solid. Before the gel material is completely cured, it is stretched biaxially. The stretching temperature is controlled at 80-120℃ and the longitudinal and transverse stretching ratios are 2:1 to 4:

1. The stretched material is washed and dried to obtain a composite material blank with a pre-oriented structure. (4) Hot pressing: The dried blank is mixed with the functional synergistic components evenly; the mixture is hot pressed at a temperature of 385°C and a pressure of 35 MPa for 90 minutes; after hot pressing, the temperature is slowly reduced to below 200°C and then cooled to room temperature.

6. The preparation method according to claim 5, characterized in that, In step (1), the acidification treatment specifically involves placing boron nitride nanofibers in a mixed acid solution of concentrated sulfuric acid and concentrated nitric acid with a volume ratio of 3:1 and refluxing at 80°C for 2 hours; the silane coupling agent treatment specifically involves dispersing nano-titanium dioxide whiskers in an ethanol solution, adding γ-aminopropyltriethoxysilane, and stirring at 75°C for 4 hours.

7. The preparation method according to claim 5, characterized in that, In step (2), the mass fraction of the polyether ether ketone sulfuric acid solution is 20%; the high-speed shear dispersion is performed at a speed of 8000 rpm for 30 minutes.

8. The preparation method according to claim 5, characterized in that, In step (3), the longitudinal and transverse stretching ratios of the biaxial stretching are both 3:1, and the stretching rate is 10 mm / min.

9. The preparation method according to claim 5, characterized in that, In step (4), the program controls the slow cooling rate to be 1-3℃ / min.

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