Multi-component synergistic reinforced polyetheretherketone composites and their preparation methods
By using a multi-component synergistic reinforcement of polyetheretherketone (PEEK) composite materials, the synergistic effect of carbon fiber, graphite, and polytetrafluoroethylene (PTFE) was utilized to solve the problems of thermal conductivity, frictional thermal failure, and mud and sand erosion of PEEK materials under complex working conditions, thereby improving high load-bearing capacity, self-lubrication, and wear resistance.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- WUHAN UNIV OF TECH
- Filing Date
- 2026-03-06
- Publication Date
- 2026-06-02
AI Technical Summary
Existing PEEK materials face problems such as poor thermal conductivity, frictional heat failure, insufficient water lubrication performance, and erosion by mud and sand under complex working conditions, making it difficult to simultaneously achieve high load-bearing capacity, heat dissipation, and self-lubricating properties.
A multi-component synergistic reinforced polyetheretherketone composite material is adopted, comprising carbon fiber, flake graphite and polytetrafluoroethylene. Through specific drying, mixing and melt blending processes, a synergistic mechanism of rigid skeleton-lubricating reservoir-film forming agent is constructed to enhance the thermal conductivity and self-lubricating properties of the material.
It significantly extends the life of extreme dry friction, reduces the coefficient of friction and wear rate under water lubrication, improves the resistance to mud and sand erosion, and achieves excellent wear resistance under all working conditions.
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Figure CN122127768A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of polymer material modification and tribology technology, specifically, it relates to multi-component synergistic reinforced polyether ether ketone composite materials and their preparation methods. Background Technology
[0002] Polyetheretherketone (PEEK) is a high-performance specialty engineering plastic widely used in marine propulsion bearings, hydraulic systems, and aerospace components. However, existing PEEK materials face significant challenges under complex real-world operating conditions: (1) Dry friction heat failure: Pure PEEK has a low thermal conductivity. During the start-up and shutdown phase or under dry friction conditions caused by accidental flow interruption, the friction heat is difficult to dissipate, and thermal softening and adhesive wear are very likely to occur, leading to catastrophic failure.
[0003] (2) Water lubrication wear: Although water can play a cooling role, pure PEEK has low surface energy, making it difficult to form a stable fluid lubrication film, and its hardness is relatively insufficient.
[0004] (3) Sediment erosion problem: In ships and hydraulic machinery, the medium often contains sediment. Although existing single fiber reinforced PEEK (such as glass fiber reinforced) has high hardness, it is prone to fiber pull-out due to weak interfacial bonding, resulting in three-body wear, which in turn aggravates wear; while single PTFE modified PEEK has good lubrication, but poor load-bearing capacity and is easily plowed by sediment particles.
[0005] Current technologies struggle to simultaneously achieve four properties: high load-bearing capacity, high heat dissipation, self-lubrication, and resistance to silt and sand. Therefore, developing a PEEK composite material adaptable to all working conditions is of great significance. In view of this, the present invention is proposed. Summary of the Invention
[0006] To solve the above-mentioned technical problems, the basic concept of the technical solution adopted by the present invention is as follows: The multi-component synergistic reinforced polyetheretherketone composite material, by mass percentage, comprises: 5%-15% carbon fiber, 5%-15% flake graphite, 5%-15% polytetrafluoroethylene, with the balance being polyetheretherketone resin.
[0007] In a preferred embodiment of the present invention, the components, by mass percentage, include: 10% carbon fiber, 10% flake graphite, 10% polytetrafluoroethylene, and 70% polyetheretherketone resin.
[0008] As a preferred embodiment of the present invention, the present invention also discloses a method for preparing a multi-component synergistic reinforced polyether ether ketone composite material, comprising the following steps: Step S1: Raw material drying pretreatment: Dry polyether ether ketone resin at 150℃ for 3-4 hours, carbon fiber at 110℃-120℃ for 4 hours, polytetrafluoroethylene powder at 80℃ for 2 hours, and flake graphite at room temperature or low temperature. Step S2: Stepwise premixing: Add the dried polyetheretherketone resin, flake graphite, and polytetrafluoroethylene powder to a high-speed mixer and premix at 500 rpm for 5-10 minutes to obtain a premix. Step S3: Side-feed melt blending extrusion: The premix from step S2 is added to the main feed port of a twin-screw extruder with a side feed port and a vacuum exhaust system. After the resin melts, the dried carbon fiber is added through the side feed port downstream of the melting section. The extrusion temperature is gradually increased from 340°C in the feed zone to 375°C-385°C in the die head zone. The screw speed is 100-200 rpm. The extruded strip is cooled, air-dried, and pelletized to obtain composite particles. Step S4: High-temperature pressure injection molding: After drying the composite particles again at 150℃, injection molding is performed. The mold temperature is controlled at 170℃-190℃, and the pressure is controlled at 100-120MPa to obtain composite material parts.
[0009] In a preferred embodiment of the present invention, the premixing time of the high-speed mixer in step S2 is 7-9 minutes.
[0010] In a preferred embodiment of the present invention, in step S3, the temperature of the die head area of the twin-screw extruder is 380°C and the screw speed is 140-160 rpm.
[0011] In a preferred embodiment of the present invention, in step S4, the mold temperature for injection molding is 175℃-185℃, and the holding pressure is 105-115MPa.
[0012] In a preferred embodiment of the present invention, in step S4, the re-drying time of the composite particles is 3-4 hours.
[0013] Compared with the prior art, the present invention has the following advantages: (1) Extreme dry friction life extended by 6 times: In the stepped loading extreme dry friction test, the average failure time of the material of the present invention (PEEK-CGP10) reached 1050 seconds, which far exceeded that of pure PEEK (175 seconds) and 30% carbon fiber reinforced PEEK (830 seconds).
[0014] (2) Achieving super-lubricated low wear under water lubrication: Under high water-lubricated conditions with a PV value of 10 MPa·m / s, the coefficient of friction is as low as 0.015 (a reduction of 37.5%), and the wear rate is only 0.170 μm / h (a reduction of 73.56%).
[0015] (3) Excellent resistance to erosion by mud and sand: In 88μm coarse-grained mud and sand water, the wear rate is reduced by 35.7% compared with pure PEEK. In 15μm fine-grained mud and sand water, the friction coefficient drops to 0.021, and there are no obvious furrows on the surface, showing extremely strong resistance to particle embedding.
[0016] The specific embodiments of the present invention will now be described in further detail with reference to the accompanying drawings. Attached Figure Description
[0017] In the attached diagram: Figure 1 This is a flowchart illustrating the preparation process of the composite material of the present invention; Figure 2 Schematic diagram of friction and wear mechanism; Figure 3 Comparison of failure times under extreme dry friction conditions; Figure 4 This is a comparison chart of wear rates under different particle sizes of silt and water environments. Detailed Implementation
[0018] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments will be clearly and completely described below with reference to the accompanying drawings. The following embodiments are used to illustrate the present invention.
[0019] This invention provides a multi-component synergistically reinforced polyetheretherketone composite material adapted to complex friction conditions. The basic components of this material, by mass percentage, include: 5% to 15% carbon fiber, 5% to 15% flake graphite, 5% to 15% polytetrafluoroethylene, and the balance being polyetheretherketone resin.
[0020] In a preferred embodiment of the invention, the optimal ratio is 10% carbon fiber, 10% flake graphite, and 10% polytetrafluoroethylene (PTFE), with the remainder being 70% polyetheretherketone (PEEK). This specific ternary component design aims to utilize the physical properties of different fillers to construct a composite system that combines high load-bearing capacity (provided by carbon fiber), high thermal conductivity (provided by carbon fiber and graphite), and excellent self-lubricating properties (provided by graphite and PTFE).
[0021] For the aforementioned composite material, this invention employs a preparation process that maximizes fiber length retention and ensures uniform dispersion. First, each raw material undergoes differentiated drying pretreatment to remove moisture and prevent degradation during processing. Specifically, polyetheretherketone resin is dried at 150°C for 3 to 4 hours, carbon fiber at 110°C to 120°C for approximately 4 hours, polytetrafluoroethylene powder is dried at 80°C for 2 hours to prevent clumping, and graphite is kept dry at room temperature or a low-temperature environment. After pretreatment, a crucial step-by-step mixing operation is performed: the dried polyetheretherketone particles, flake graphite powder, and polytetrafluoroethylene powder are placed in a high-speed mixer and premixed at 500 rpm for 5 to 10 minutes to ensure the lubricating filler is uniformly coated on the resin particle surface. It is important to note that carbon fiber is not added at this stage to avoid the strong shear forces during premixing damaging the fiber structure.
[0022] The subsequent melt blending step is carried out in a twin-screw extruder equipped with a side feed port and a vacuum exhaust system. The premixed material without carbon fiber is fed into the main feed port of the extruder, and the resin is melted by the shear heat of the screw and an external heating source. After the resin has completely melted in the melting section of the extruder, the dried carbon fiber is added through the side feed port located downstream of the melting section. This process arrangement can effectively shorten the residence time of carbon fiber in the screw, significantly reduce fiber breakage caused by mechanical shearing, and thus maximize the retention of the fiber aspect ratio to maintain the mechanical reinforcement effect of the material. The temperature setting during the extrusion process is gradient-distributed, gradually increasing from 340°C in the feed zone to 375°C to 385°C in the die head zone, and the screw speed is controlled at 100 to 200 rpm. The extruded strip is cooled by circulating water, air-dried, and then pelletized to obtain composite particles.
[0023] Finally, the prepared composite particles are dried again at 150°C and then injection molded. In order to improve the crystallinity and surface hardness of the material, the mold temperature needs to be precisely controlled in the high temperature range of 170°C to 190°C, and the molding is carried out under a holding pressure of 100 to 120 MPa to finally obtain the target parts.
[0024] This technical solution, through the aforementioned formulation and process, constructs a synergistic mechanism of rigid skeleton, lubricating reservoir, and film-forming agent within the material: carbon fiber constructs a three-dimensional rigid network within the matrix and provides thermal conductivity channels, effectively dispersing load and dissipating frictional heat, preventing thermal failure under extreme dry friction; while graphite and polytetrafluoroethylene work synergistically, preferentially precipitating on the friction surface to form a dense, continuous composite transfer film with low shear strength. Especially in water-lubricated environments containing silt, this transfer film, together with the microstructure of the material surface, generates a size screening effect. It can both block the deep plowing of coarse particles (e.g., 88μm) through the rigid skeleton and capture fine particles (e.g., 15μm) to form rolling friction through the surface texture, thereby achieving excellent wear resistance under all working conditions from extreme dry friction to silty water lubrication.
[0025] Example 1: Preparation of multi-component synergistically reinforced polyetheretherketone composite materials Raw material preparation: Weigh out 70% polyetheretherketone resin, 10% carbon fiber, 10% flake graphite, and 10% polytetrafluoroethylene powder by weight percentage; Drying pretreatment: Polyetheretherketone resin was dried in an oven at 150℃ for 3.5h; carbon fiber was dried in an oven at 115℃ for 4h; polytetrafluoroethylene powder was dried in an oven at 80℃ for 2h; flake graphite was placed in a room temperature drying environment for later use. Stepwise premixing: The dried polyetheretherketone resin, flake graphite, and polytetrafluoroethylene powder are added to a high-speed mixer and premixed at 500 rpm for 8 minutes to obtain a premix. Side-feed extrusion: The premixed material is added to the main feed port of the twin-screw extruder. The extrusion temperature gradient is: 340℃ in the feeding zone, 355℃ in the compression zone, 370℃ in the melting zone, and 380℃ in the die head zone; the screw speed is 150 rpm; after the resin in the melting zone has completely melted, the dried carbon fiber is added through the side feed port. After vacuum degassing and extrusion, the material strip is cooled by circulating water, air-dried, and granulated to obtain composite particles. Injection molding: The composite particles are dried at 150℃ for 3 hours, added to the injection molding machine, the mold temperature is 180℃, the holding pressure is 110MPa, and the composite material standard sample is obtained by injection molding.
[0026] Example 2: Preparation of composite materials with different carbon fiber ratios The preparation process was the same as in Example 1, except that the carbon fiber ratio was adjusted to 5%, flake graphite 10%, polytetrafluoroethylene 10%, and polyetheretherketone resin 75% to obtain a composite material sample.
[0027] Example 3: Preparation of composite materials with different flake graphite ratios The preparation process was the same as in Example 1, except that the proportion of flake graphite was adjusted to 15%, carbon fiber to 10%, polytetrafluoroethylene to 10%, and polyetheretherketone resin to 65%, to obtain a composite material sample.
[0028] Performance testing The above-described embodiments and comparative samples (pure PEEK, 30% carbon fiber reinforced PEEK, and 30% glass fiber reinforced PEEK) were subjected to performance tests under extreme dry friction, water lubrication, and water lubrication conditions containing mud and sand. The test results are as follows: Extreme dry friction test: The failure time of the PEEK-CGP10 sample in Example 1 was 1050s, the failure time of the sample in Example 2 was 920s, and the failure time of the sample in Example 3 was 980s, all of which were much higher than that of pure PEEK (175s) and 30% carbon fiber reinforced PEEK (830s). High water-carrying lubrication test (PV=10MPa・m / s): The friction coefficient of the sample in Example 1 was 0.015 and the wear rate was 0.170μm / h; the friction coefficient of the sample in Example 2 was 0.018 and the wear rate was 0.210μm / h; and the friction coefficient of the sample in Example 3 was 0.016 and the wear rate was 0.185μm / h. All of these results were better than the control sample. Lubrication test in muddy water: In 88μm coarse-grained muddy water, the wear rate of the sample in Example 1 was reduced by 35.7% compared with pure PEEK; In 15μm fine-grained muddy water, the friction coefficient of the sample in Example 1 was 0.021, and there were no obvious furrows on the surface, indicating the best erosion resistance.
[0029] like Figure 3 and 4 As shown in the test results above, the composite material of the present invention has excellent comprehensive performance in the range of 5% to 15% of the component ratio. Among them, the ratio of 10% carbon fiber + 10% flake graphite + 10% polytetrafluoroethylene + 70% PEEK is the best solution, with the best wear resistance under all working conditions.
[0030] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.
Claims
1. A multi-component synergistically reinforced polyetheretherketone composite material, characterized in that... By mass percentage, the components include: 5%-15% carbon fiber, 5%-15% flake graphite, 5%-15% polytetrafluoroethylene, and the balance is polyetheretherketone resin.
2. The multi-component synergistic reinforced polyetheretherketone composite material according to claim 1, characterized in that, By weight percentage, the components include: 10% carbon fiber, 10% flake graphite, 10% polytetrafluoroethylene, and 70% polyetheretherketone resin.
3. A method for preparing a multi-component synergistically reinforced polyetheretherketone composite material as described in claim 1 or 2, characterized in that, Includes the following steps: Step S1: Raw material drying pretreatment: Dry polyether ether ketone resin at 150℃ for 3-4 hours, carbon fiber at 110℃-120℃ for 4 hours, polytetrafluoroethylene powder at 80℃ for 2 hours, and flake graphite at room temperature or low temperature. Step S2: Stepwise premixing: Add the dried polyetheretherketone resin, flake graphite, and polytetrafluoroethylene powder to a high-speed mixer and premix at 500 rpm for 5-10 minutes to obtain a premix. Step S3: Side-feed melt blending extrusion: The premix from step S2 is added to the main feed port of a twin-screw extruder with a side feed port and a vacuum exhaust system. After the resin melts, the dried carbon fiber is added through the side feed port downstream of the melting section. The extrusion temperature is gradually increased from 340°C in the feed zone to 375°C-385°C in the die head zone. The screw speed is 100-200 rpm. The extruded strip is cooled, air-dried, and pelletized to obtain composite particles. Step S4: High-temperature pressure injection molding: After drying the composite particles again at 150℃, injection molding is performed. The mold temperature is controlled at 170℃-190℃, and the pressure is controlled at 100-120MPa to obtain composite material parts.
4. The method for preparing the multi-component synergistically reinforced polyetheretherketone composite material according to claim 3, characterized in that, In step S2, the premixing time of the high-speed mixer is 7-9 minutes.
5. The method for preparing the multi-component synergistically reinforced polyetheretherketone composite material according to claim 3, characterized in that, In step S3, the temperature of the die head area of the twin-screw extruder is 380℃, and the screw speed is 140-160 rpm.
6. The method for preparing the multi-component synergistically reinforced polyetheretherketone composite material according to claim 3, characterized in that, In step S4, the mold temperature for injection molding is 175℃-185℃, and the holding pressure is 105-115MPa.
7. The method for preparing the multi-component synergistically reinforced polyetheretherketone composite material according to claim 3, characterized in that, In step S4, the re-drying time of the composite particles is 3-4 hours.