A polymer-based wear-resistant composite material filled with core-shell particles and a preparation method thereof

Abstract

The present invention provides a polymer-based wear-resistant composite material filled with core-shell particles and a preparation method thereof, belonging to the technical field of polymer-based wear-resistant composite materials. The core-shell particle filler provided by the present invention has a graphene shell and a nano-metal particle as the central core; the diameter of the core-shell particle filler is 100 nm - 300 nm. The core-shell particle filler is compounded with a polymer matrix to obtain a polymer-based wear-resistant composite material filled with core-shell particles. In the present invention, the core-shell particle filler can be used as a solid lubricant in the polymer-based composite material, can well improve the friction performance of the composite material at a low content, has good wear resistance and self-lubricity, can effectively solve the dispersion problem of the filler in the matrix, and can reduce the cost.

Description

Technical Field

[0001] The present invention relates to the technical field of polymer-based wear-resistant composite materials, in particular to a polymer-based wear-resistant composite material filled with core-shell particles and a preparation method thereof. Background Art

[0002] Engineering plastics refer to a class of polymer materials that can be used as structural materials, withstand mechanical stress over a wide temperature range, and operate in harsh chemical and physical environments. Engineering plastics can be categorized into general-purpose engineering plastics and specialty engineering plastics. The former primarily includes polyamides, polyoxymethylene, and polyphenylene oxide; the latter primarily refers to engineering plastics with long-term operating temperatures above 150°C, and their primary varieties include polyimides, polysulfones, polyphenylene sulfide, polytetrafluoroethylene, and polyetheretherketone. Due to their excellent stability, heat and chemical resistance, and high strength, engineering plastics have a wide range of applications, and their demand continues to grow rapidly. One of the primary uses of engineering plastics is as a wear-resistant alternative to metal. Compared to metals, engineering plastics offer lightweight, high specific strength, ease of processing, high production efficiency, and outstanding friction reduction and wear resistance. With the increasing demand for system reliability and long life in modern high-end equipment, a single engineering plastic often cannot simultaneously meet the system's requirements for self-lubricity and wear resistance. Consequently, filler-modified engineering plastics are needed to meet these broader application requirements.

[0003] Currently, researchers commonly use the following types of fillers and modified materials to improve the tribological properties of polymers: metal and compound fillers such as copper, lead, and tin; inorganic fillers such as carbon fiber, molybdenum disulfide, and graphite; and nanofillers such as nanoalumina, graphene, and carbon nanotubes. Improving the friction properties of polymers with a single filler is often insufficient to meet performance requirements. The introduction of multiple fillers can leverage their individual functions, maintaining the inherent advantages of the polymer matrix while fully leveraging the synergistic and complementary effects of the various components. This improves and overcomes the defects of the polymer matrix, achieving optimal overall performance and further enhancing the friction properties of the polymer. Yongwu Zhao et al. (Materials, 2022, 15, 7078) studied the friction properties of polyetheretherketone / polytetrafluoroethylene composites reinforced with carbon fiber and graphite. The study demonstrated that the synergistic effect of carbon fiber and graphite effectively improved the wear resistance of the composite. However, there are still some shortcomings in the actual application of multi-component composite modified polymer-based composite materials. The content of multiple fillers in the composite materials is often very high, and some high-content fillers are easy to agglomerate and difficult to disperse evenly in the matrix, which will be detrimental to the improvement of the mechanical properties and friction properties of the composite materials. Summary of the Invention

[0004] To solve the above problems, the present invention provides a polymer-based wear-resistant composite material filled with core-shell particles and a preparation method thereof. In the present invention, the core-shell particle filler can be used as a solid lubricant in the polymer-based composite material, can well improve the friction performance of the composite material at a low content, has good wear resistance and self-lubricating properties, can effectively solve the dispersion problem of the filler in the matrix, and can reduce the cost.

[0005] To achieve the above object, the present invention provides the following technical solution: a core-shell particle filler, the shell is graphene, and the central core is a nano metal particle; the diameter of the core-shell particle filler is 100nm - 300nm.

[0006] Preferably, the nano metal particles include Cu, Ag, Zn, Sn or Al.

[0007] The present invention also provides a preparation method of the core-shell particle filler. Under vacuum conditions, after heating the β-diketone metal complex, a reducing gas is introduced for heat preservation to reduce the β-diketone metal complex, and the obtained core-shell particle filler is obtained;

[0008] The structural formula of the β-diketone metal complex is: Wherein, R1 and R2 are each independently selected from CH3-, C2H5-, n-C3H7-, i-CH3, n-C4H9-, i-C4H9-, s-C4H9-, t-C4H9-, CH3O-, C2H5O-, Ph-, p-CH3-Ph-, p-C2H5-Ph-, p-CH3O-Ph- or p-C2H5O-Ph-; M n+ is Cu 2+ 、Ag + 、Zn 2+ 、Sn 2+ or Al 3+ .

[0009] Preferably, the vacuum condition is that the vacuum degree ≤ 60Pa.

[0010] Preferably, the temperature for heating the β-diketone metal complex is heated to 450 - 600 °C; the heat preservation time is 150 - 200 minutes.

[0011] Preferably, the reducing gas includes CO or H2.

[0012] The present invention also provides an application of the core-shell particle filler in the preparation of a polymer-based composite material.

[0013] The present invention also provides a polymer-based wear-resistant composite material filled with core-shell particles, and the raw materials include a polymer and the core-shell particle filler.

[0014] Preferably, the polymer is polyether ether ketone, polyphenylene sulfide, polyimide, polyetherimide, nylon 66 or polyoxymethylene.

[0015] The present invention also provides a method for preparing the core-shell particle-filled polymer-based wear-resistant composite material. After uniformly mixing the core-shell particle filler with the polymer, it is molded by pressing to obtain the core-shell particle-filled polymer-based composite material.

[0016] The present invention discloses the following technical effects:

[0017] 1. The shell of the nano core-shell particle filler provided by the present invention is composed of layered graphene, and the core is metal nanoparticles. The two-dimensional graphene sheets are connected by van der Waals forces. The low shear force between adjacent atomic layers makes the atomic layers easy to slide, thus endowing it with lubricating properties. In addition, due to the nano-structure of the core-shell particles, it can easily enter the friction contact surface to form a lubricating film, which can reduce the surface roughness and repair wear.

[0018] 2. The nano core-shell particle filler provided by the present invention can be used as a solid lubricant for various engineering plastics to improve the friction performance of engineering plastics, rather than being limited to being used as a lubricating oil additive. The core-shell particles of the present invention compound graphene with metal nanoparticles, solving the limitation of the improvement of friction performance brought by a single filler, and solving the problems of large dosage and poor dispersibility of existing various fillers.

[0019] 3. The present invention prepares a composite material by compounding the core-shell particle filler as a solid lubricant with a polymer matrix. When friction occurs, the core-shell particles are peeled off, and the outer-layer flaky graphene is peeled off from the surface of the core-shell particles to form a transfer film together with the peeled polymer matrix; the exposed metal nanoparticles roll at the friction interface, playing the role of a "nano bearing" and strengthening the anti-shear ability of the transfer film; at the same time, the metal nanoparticles will induce a friction chemical reaction during the friction process, and this chemical reaction is beneficial to the formation of a high-quality transfer film.

[0020] 4. A low content of the core-shell particle filler can effectively improve the friction performance of the composite material, solve the problem of poor dispersibility, and reduce the cost. Description of the Drawings

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required to be used in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0022] Figure 1 It is the SEM image of the core-shell particles obtained in Example 1. Detailed Embodiments

[0023] The various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be construed as limiting the present invention, but rather as a more detailed description of certain aspects, features, and implementation manners of the present invention.

[0024] It should be understood that the terms used in the present invention are only for describing specific embodiments and are not intended to limit the present invention. Additionally, for the numerical ranges in the present invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Any intermediate value within any stated value or stated range, as well as each smaller range between any other stated value or intermediate value within the stated range, is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded from the range.

[0025] Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the art to which the present invention pertains. Although the present invention only describes preferred methods and materials, any methods and materials similar or equivalent to those described herein can also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials related to the documents. In case of conflict with any incorporated document, the content of this specification shall prevail.

[0026] Without departing from the scope or spirit of the present invention, various improvements and changes can be made to the specific embodiments of the present invention specification, which are obvious to those skilled in the art. Other embodiments obtained from the specification of the present invention are obvious to those skilled in the art. The specification and examples of the present invention are merely exemplary.

[0027] Regarding the use of "comprising", "including", "having", "containing", etc. herein, they are all open-ended terms, meaning including but not limited to.

[0028] The present invention provides a core-shell particle filler, where the shell is graphene and the central core is a nano-metal particle; the diameter of the core-shell particle filler is 100 nm - 300 nm.

[0029] In some embodiments, the nano-metal particle includes Cu, Ag, Zn, Sn, or Al.

[0030] The present invention also provides a preparation method of the core-shell particle filler. Under vacuum conditions, after heating the β-diketone metal complex, a reducing gas is introduced for heat preservation to reduce the β-diketone metal complex, thereby obtaining the core-shell particle filler;

[0031] The structural formula of the β-diketone metal complex is: Among them, R1 and R2 are each independently selected from CH3-, C2H5-, n-C3H7-, i-CH3, n-C4H9-, i-C4H9-, s-C4H9-, t-C4H9-, CH3O-, C2H5O-, Ph-, p-CH3-Ph-, p-C2H5-Ph-, p-CH3O-Ph- or p-C2H5O-Ph-; M n+ is Cu 2+ , Ag + , Zn 2+ , Sn 2+ or Al 3+ .

[0032] In some embodiments, the vacuum condition is that the vacuum degree ≤ 60 Pa.

[0033] In some embodiments, the temperature for heating the β-diketone metal complex is heated to 450 - 600 °C; the time for heat preservation is 150 - 200 minutes.

[0034] In some embodiments, the temperature for heating the β-diketone metal complex is heated to 550 °C; the time for heat preservation is 180 minutes.

[0035] In some embodiments, the reducing gas includes CO or H2.

[0036] In some embodiments, the reducing gas is H2.

[0037] In some embodiments, after introducing the reducing gas for heat preservation to reduce the acetylacetone metal complex, the present invention further includes the steps of naturally cooling to room temperature, washing, centrifuging, and drying.

[0038] In some embodiments, the washing is to wash and remove the unreacted acetylacetone metal complex in the product with an organic solvent; the organic solvent is chloroform, benzene, carbon tetrachloride, ether, methanol, ethanol, isopropanol, n-butanol, dimethyl sulfoxide, ethyl acetate, acetone, butanone, pyridine or tetrahydrofuran, preferably ethanol, acetone or ethyl acetate.

[0039] The present invention also provides the application of the core-shell particle filler in the preparation of polymer matrix composites.

[0040] The present invention also provides a polymer matrix wear-resistant composite filled with core-shell particles, and the raw materials include a polymer and the core-shell particle filler.

[0041] In some embodiments, the polymer is polyether ether ketone, polyphenylene sulfide, polyimide, polyetherimide, nylon 66 or polyoxymethylene; the particle size of the polymer is less than 100 μm.

[0042] The present invention does not have special limitations on the type of the polymer, and commercially available products well-known in the art that meet the above particle sizes can be used. The polymers within the scope of the present invention are common engineering plastics and special engineering plastics for reducing friction nowadays. However, in view of the different technical requirements of modern high-end equipment for materials, other polymer materials can also be tried for their feasibility in the solution of the present invention to meet the requirements for wide use in various fields of friction materials.

[0043] In some embodiments, the mass ratio of the core-shell particle filler to the polymer is (2-20):80.

[0044] The mass ratio of the core-shell particles to the polymer set in the present invention is (2-20):80. Within this range, the mass fraction of the filler is lower than 20%, which is beneficial to the more uniform dispersion of the filler in the matrix, and the friction performance of the composite material reinforced with a low content of the filler is significantly improved. If the mass fraction of the filler is higher than 20%, it will lead to uneven dispersion of the filler in the polymer matrix and agglomeration, and the friction performance of the composite material reinforced with a high content of the filler is not significantly improved compared with that of the composite material filled with a low content of the filler, and even decreases.

[0045] The present invention also provides a method for preparing the core-shell particle-filled polymer-based wear-resistant composite material. After uniformly mixing the core-shell particle filler and the polymer, it is molded by compression molding to obtain the core-shell particle-filled polymer-based composite material.

[0046] In some embodiments, the method of uniformly mixing the core-shell particle filler and the polymer is ball milling blending. This method can make the mixing between the powder materials more uniform.

[0047] In some embodiments, after uniformly mixing the core-shell particle filler and the polymer, it further includes the step of vacuum drying the mixture.

[0048] In some embodiments, the method of compression molding is vacuum hot pressing. The present invention performs hot pressing in a vacuum environment to avoid the oxidation of metal particles in the nano core-shell particles during the hot pressing process.

[0049] In the present invention, the core-shell particle filler (with a graphene shell and a nano-metal particle core) can be used as a solid lubricant. On the one hand, as nano-particles, this filler has a self-reinforcing effect. Graphene has a single-layer structure with high modulus and high strength. The low shear force between adjacent atomic layers makes it easy for atomic layers to slide, and it has a high specific surface area, making it easy to adsorb onto the contact surface, thus preventing direct contact between the friction pairs. During the friction process, the outer flaky graphene is peeled off from the surface of the core-shell particles and forms a transfer film together with the peeled polymer matrix. The inner core metal nanoparticles are exposed. The metal nanoparticles have an ideal spherical shape and good dispersibility. The metal nanoparticles can act as "nano-bearings" during the friction process, converting sliding friction into rolling friction, thereby reducing the friction coefficient and showing excellent anti-friction performance. On the other hand, this filler can well improve the friction performance of the composite material at a relatively low content, has good wear resistance and self-lubrication, can effectively solve the dispersion problem of the filler in the matrix, and reduce costs.

[0050] To better understand the present invention, the content of the present invention will be further clarified below in conjunction with embodiments. However, the content of the present invention is not limited to the following embodiments. The raw materials and reagents used in the embodiments can be obtained through commercial channels without special instructions.

[0051] The types of polymers used in the embodiments are one of polyether ether ketone (PEEK), polyphenylene sulfide (PPS), polyetherimide (PEI), and nylon (PA), and all are fine powders with a particle size less than 100 μm; the models of the polymers used are PEEK (150PF), PPS (DIC FZ1160), PEI (Ultem 1000), and PA66 (Zytel 101LNC010). The fillers used in the comparative examples are graphite (Graphite, 8000 mesh), polytetrafluoroethylene (PTFE, D50 = 10 μm), short carbon fiber (SCF, with a diameter of 5 - 10 μm and an aspect ratio of 5:1 - 10:1), and spherical copper powder (Cu, with a diameter of 1 μm).

[0052] The diameter of the core-shell particles prepared in the embodiments is 100 nm - 300 nm.

[0053] The β-diketone metal complex used in the embodiments is wherein, R1 and R2 are each independently selected from CH3-, C2H5-, n-C3H7-, i-CH3, n-C4H9-, i-C4H9-, s-C4H9-, t-C4H9-, CH3O-, C2H5O-, Ph-, p-CH3-Ph-, p-C2H5-Ph-, p-CH3O-Ph- or p-C2H5O-Ph-, and M n+ is Cu 2+ 、Ag +, Zn 2+ , Sn 2+ or Al 3+ .

[0054] Example 1

[0055] Under a vacuum condition of 60 Pa, 10 g of a β-diketone metal complex (where R1 = R2 = CH3-, M n+ is Cu 2+ ) was heated to 550 °C in a tube furnace, and H2 was introduced (under argon protection) to reduce the β-diketone metal complex, and it was kept warm for 180 minutes. After natural cooling, the unreacted β-diketone metal complex in the product was washed with ethanol, then centrifuged, and then dried in a vacuum oven at 60 °C for 14 hours. The SEM image of the obtained Cu@Gr core-shell particles is shown in Appendix Figure 1 . It can be seen that the Cu@Gr core-shell particles exhibit a good spherical core-shell structure, graphene can uniformly coat the surface of the nano-metal particles, and the particle size of the Cu@Gr core-shell particles is mostly in the range of 100 nm - 300 nm, indicating that this method can prepare Cu@Gr core-shell particles with a uniform particle size distribution and a complete core-shell structure.

[0056] 0.5 g, 1.5 g, 2.5 g, and 5 g of Cu@Gr core-shell particles and 20 g of PEEK were respectively taken and placed in a planetary ball mill, and mixed at 0 °C and a rotation speed of 200 rpm for 8 hours. After mixing, the composite material powder was placed in a vacuum drying oven, the temperature was set at 100 °C, and dried for 2 hours.

[0057] The composite materials obtained by molding the above 4 dried composite materials under the conditions of 10 Mpa and 360 °C were respectively denoted as 0.5 g-Cu@Gr-PEEK, 1.5 g-Cu@Gr-PEEK, 2.5 g-Cu@Gr-PEEK, and 5 g-Cu@Gr-PEEK.

[0058] Example 2

[0059] The method was as in Example 1, the only difference being that the β-diketone metal complex (where R1 = C2H5-, R2 = C3H7-, M n+ is Ag + ) and the Cu@Gr core-shell particles were adjusted to Ag@Gr core-shell particles, and other conditions remained unchanged. The obtained composite materials were respectively denoted as 0.5 g-Ag@Gr-PEEK, 1.5 g-Ag@Gr-PEEK, 2.5 g-Ag@Gr-PEEK, and 5 g-Ag@Gr-PEEK.

[0060] Example 3

[0061] The method is the same as that in Example 1, with the only difference being that the β-diketonate metal complex (where R1 = Ph-, R2 = CH3-, M n+ is Sn 2+ ) is adjusted, the reduction of the β-diketonate metal complex with H2 is adjusted to reduction with CO, and the Cu@Gr core-shell particles are adjusted to Sn@Gr core-shell particles, while other conditions remain unchanged. The obtained composite materials are denoted as 0.5g-Sn@Gr-PEEK, 1.5g-Sn@Gr-PEEK, 2.5g-Sn@Gr-PEEK, and 5g-Sn@Gr-PEEK respectively.

[0062] Example 4

[0063] The method is the same as that in Example 1, with the only difference being that the β-diketonate metal complex (where R1 = Ph-, R2 = CH3O-, M n+ is Cu 2+ ) is adjusted, PEEK is adjusted to PPS, and the hot pressing temperature of 360 °C is adjusted to a hot pressing temperature of 320 °C, while other conditions remain unchanged. The obtained composite materials are denoted as 0.5g-Cu@Gr-PPS, 1.5g-Cu@Gr-PPS, 2.5g-Cu@Gr-PPS, and 5g-Cu@Gr-PPS respectively.

[0064] Example 5

[0065] The method is the same as that in Example 1, with the only difference being that the β-diketonate metal complex (where R1 = C3H7-, R2 = CH3O-, M n+ is Al 3+ ) is adjusted, the Cu@Gr core-shell particles are adjusted to Al@Gr core-shell particles, PEEK is adjusted to PPS, and the hot pressing temperature of 360 °C is adjusted to a hot pressing temperature of 320 °C, while other conditions remain unchanged. The obtained composite materials are denoted as 0.5g-Al@Gr-PPS, 1.5g-Al@Gr-PPS, 2.5g-Al@Gr-PPS, and 5g-Al@Gr-PPS respectively.

[0066] Example 6

[0067] The method is the same as that in Example 1, with the only difference being that the β-diketonate metal complex (where R1 = C4H9-, R2 = C2H5O-, M n+ is Zn 2+ ) is adjusted, the Cu@Gr core-shell particles are adjusted to Zn@Gr core-shell particles, PEEK is adjusted to PPS, and the hot pressing temperature of 360 °C is adjusted to a hot pressing temperature of 320 °C, while other conditions remain unchanged. The obtained composite materials are denoted as 0.5g-Zn@Gr-PPS, 1.5g-Zn@Gr-PPS, 2.5g-Zn@Gr-PPS, and 5g-Zn@Gr-PPS respectively.

[0068] Example 7

[0069] The method is the same as that of Example 1, except that the β-diketone metal complex (where R1 = p-CH3-Ph-, R2 = CH3-, M n+ is Zn 2+ ) is adjusted, the reduction of the β-diketone metal complex with H2 is adjusted to reduction with CO, the Cu@Gr core-shell particles are adjusted to Zn@Gr core-shell particles, PEEK is adjusted to PEI, and the hot pressing temperature of 360 °C is adjusted to a hot pressing temperature of 340 °C, with other conditions remaining unchanged. The obtained composite materials are denoted as 0.5g-Zn@Gr-PEI, 1.5g-Zn@Gr-PEI, 2.5g-Zn@Gr-PEI, and 5g-Zn@Gr-PEI respectively.

[0070] Example 8

[0071] The method is the same as that of Example 1, except that the β-diketone metal complex (where R1 = p-CH3O-Ph-, R2 = Ph-, M n+ is Ag + ) is adjusted, the Cu@Gr core-shell particles are adjusted to Ag@Gr core-shell particles, PEEK is adjusted to PEI, and the hot pressing temperature of 360 °C is adjusted to a hot pressing temperature of 340 °C, with other conditions remaining unchanged. The obtained composite materials are denoted as 0.5g-Ag@Gr-PEI, 1.5g-Ag@Gr-PEI, 2.5g-Ag@Gr-PEI, and 5g-Ag@Gr-PEI respectively.

[0072] Example 9

[0073] The method is the same as that of Example 1, except that the β-diketone metal complex (where R1 = i-C4H9-, R2 = C2H5O-, M n+ is Sn 2+ ) is adjusted, the Cu@Gr core-shell particles are adjusted to Sn@Gr core-shell particles, PEEK is adjusted to PEI, and the hot pressing temperature of 360 °C is adjusted to a hot pressing temperature of 340 °C, with other conditions remaining unchanged. The obtained composite materials are denoted as 0.5g-Sn@Gr-PEI, 1.5g-Sn@Gr-PEI, 2.5g-Sn@Gr-PEI, and 5g-Sn@Gr-PEI respectively.

[0074] Example 10

[0075] The method is the same as that of Example 1, except that the β-diketone metal complex (where R1 = R2 = Ph-, M n+ is Cu 2 +) Adjust the reduction of the β-diketone metal complex with H2 to reduction with CO, adjust PEEK to PA66, and adjust the hot pressing temperature of 360 °C to 280 °C, with other conditions remaining unchanged. The obtained composite materials are respectively denoted as 0.5g-Cu@Gr-PA66, 1.5g-Cu@Gr-PA66, 2.5g-Cu@Gr-PA66, and 5g-Cu@Gr-PA66.

[0076] Example 11

[0077] The method is as in Example 1, with the only difference being that the β-diketone metal complex (where R1 = R2 = CH3-, M n+ is Ag + ) is adjusted, the Cu@Gr core-shell particles are adjusted to Ag@Gr core-shell particles, PEEK is adjusted to PA66, and the hot pressing temperature of 360 °C is adjusted to 280 °C, with other conditions remaining unchanged. The obtained composite materials are respectively denoted as 0.5g-Ag@Gr-PA66, 1.5g-Ag@Gr-PA66, 2.5g-Ag@Gr-PA66, and 5g-Ag@Gr-PA66.

[0078] Example 12

[0079] The method is as in Example 1, with the only difference being that the β-diketone metal complex (where R1 = R2 = CH3-, M n+ is Al 3 + ) is adjusted, the Cu@Gr core-shell particles are adjusted to Al@Gr core-shell particles, PEEK is adjusted to PA66, and the hot pressing temperature of 360 °C is adjusted to 280 °C, with other conditions remaining unchanged. The obtained composite materials are respectively denoted as 0.5g-Al@Gr-PA66, 1.5g-Al@Gr-PA66, 2.5g-Al@Gr-PA66, and 5g-Al@Gr-PA66.

[0080] Comparative Example 1

[0081] Take 20 g of PEEK, 20 g of PPS, 20 g of PEI, and 20 g of PA66 respectively and place them in a vacuum drying oven at a temperature of 100 °C for 2 hours. After drying, place them in a mold respectively and cold press for 10 minutes under a pressure of 40 MPa; then place the mold in a vacuum hot press, with the temperatures set at 360 °C, 320 °C, 340 °C, and 280 °C respectively, and the pressure set at 10 MPa, and hot press for 80 minutes. After the mold cools naturally, take out the comparative samples, and the obtained comparative samples are respectively denoted as PEEK, PPS, PEI, and PA66.

[0082] Comparative Example 2

[0083] 2 g, 5 g, 10 g, and 15 g of Graphite and 20 g of PEEK were respectively placed in a planetary ball mill and mixed at 0 °C and a rotation speed of 200 rpm for 8 hours. After mixing, the composite powder was placed in a vacuum drying oven at a temperature of 100 °C and dried for 2 hours.

[0084] The composites obtained by molding the above 4 dried composites under 10 Mpa and 360 °C were respectively denoted as 2g-Graphite / PEEK, 5g-Graphite / PEEK, 10g-Graphite / PEEK, and 15g-Graphite / PEEK.

[0085] Comparative Example 3

[0086] The method was as in Comparative Example 2, with the only differences being that Graphite was adjusted to PTFE, PEEK was adjusted to PPS, and the hot pressing temperature of 360 °C was adjusted to a hot pressing temperature of 320 °C, while other conditions remained unchanged. The obtained composites were respectively denoted as 2g-PTFE / PPS, 5g-PTFE / PPS, 10g-PTFE / PPS, and 15g-PTFE / PPS.

[0087] Comparative Example 4

[0088] The method was as in Comparative Example 2, with the only differences being that Graphite was adjusted to a mixture of PTFE and SCF (the mass ratio of PTFE to SCF was 1:1), PEEK was adjusted to PEI, and the hot pressing temperature of 360 °C was adjusted to a hot pressing temperature of 340 °C, while other conditions remained unchanged. The obtained composites were respectively denoted as 2g-PTFE / SCF / PEI, 5g-PTFE / SCF / PEI, 10g-PTFE / SCF / PEI, and 15g-PTFE / SCF / PEI.

[0089] Comparative Example 5

[0090] The method was as in Comparative Example 2, with the only differences being that Graphite was adjusted to a mixture of Graphite and Cu (the mass ratio of Graphite to Cu was 1:1), PEEK was adjusted to PA66, and the hot pressing temperature of 360 °C was adjusted to a hot pressing temperature of 280 °C, while other conditions remained unchanged. The obtained composites were respectively denoted as 2g-Graphite / Cu / PA66, 5g-Graphite / Cu / PA66, 10g-Graphite / Cu / PA66, and 15g-Graphite / Cu / PA66.

[0091] Performance Test

[0092] The friction loss performance tests were carried out on the composite materials prepared in Examples 1-12 and the comparative samples prepared in Comparative Examples 1-5. The plate samples after vacuum hot pressing were processed into cuboid splines with dimensions of 2.5×2.5×20 mm 3 for friction testing, and a tribometer was used to conduct tribological performance tests.

[0093] The pin-on-ring model was adopted for the test, where the pin was the composite material and the ring was GCr steel. The roughness of the ring was 0.15 - 0.2, the diameter of the ring was 48 mm, and the test conditions were 1 MPa, 200 rpm, and 3 h. The obtained results are shown in Tables 1-4.

[0094] Table 1: Friction Coefficients and Specific Wear Rates of PEEK, Cu@Gr-PEEK, Ag@Gr-PEEK, Sn@Gr-PEEK, and Graphite / PEEK

[0095]

[0096] Table 2: Friction Coefficients and Specific Wear Rates of PPS, Cu@Gr-PPS, Al@Gr-PPS, Zn@Gr-PPS, and PTFE / PPS

[0097]

[0098]

[0099] Table 3: Friction Coefficients and Specific Wear Rates of PEI, Zn@Gr-PEI, Ag@Gr-PEI, Sn@Gr-PEI, and PTFE / SCF / PEI

[0100]

[0101]

[0102] Table 4: Friction Coefficients and Specific Wear Rates of PA66, Cu@Gr-PA66, Ag@Gr-PA66, Al@Gr-PA66, and Graphite / Cu / PA66

[0103]

[0104]

[0105] As can be seen from Tables 1 - 4, compared with pure polymers (PEEK, PPS, PEI, PA66), polymers filled with a single filler can often only improve some friction properties, and the remaining friction properties may decrease with the addition of the filler; adding multiple fillers often requires the filler content to reach more than 30% to achieve the best effect, and the limited improvement in friction properties is due to the negative effects caused by the increase in filler content; the polymer - based composite material filled with nano - core - shell particles of the present invention has a low friction coefficient and specific wear rate, indicating that the core - shell particles can effectively enhance the tribological properties of the polymer. When the content of the core - shell particles in the composite material is about 7.5%, the composite material has the best friction and wear properties. The content of this filler is low, which can effectively solve the problem of poor dispersion of the filler in the matrix and better improve the tribological properties of the polymer.

[0106] The above are only the preferred embodiments of the present invention. It should be pointed out that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A polymer-based wear-resistant composite material filled with core-shell particles, characterized in that, The raw materials include a polymer and a core-shell particle filler; The preparation method of the core-shell particle filler is as follows: under vacuum conditions, heat the β-diketone metal complex and then introduce a reducing gas to keep it warm to reduce the β-diketone metal complex, thereby obtaining the core-shell particle filler; The structural formula of the β-diketone metal complex is as follows: wherein, R1 = Ph-, R2 = CH3-, or R1 = p-CH3-Ph-, R2 = CH3-, or R1 = R2 = Ph-; M n+ is Cu 2+ , Zn 2+ or Sn 2+ ; The vacuum conditions are a vacuum degree ≤ 60 Pa; The temperature for heating the β-diketone metal complex is heated to 550 °C; the holding time is 180 minutes; The reducing gas is CO; The shell of the core-shell particle filler is graphene, and the central core is a nano metal particle; the diameter of the core-shell particle filler is 100 nm - 300 nm; The nano metal particles include Cu, Zn or Sn.

2. The polymer-based wear-resistant composite material filled with core-shell particles according to claim 1, characterized in that The polymer is polyether ether ketone, polyphenylene sulfide, polyimide, polyetherimide, nylon 66 or polyoxymethylene.

3. A method for preparing a polymer-based wear-resistant composite material filled with core-shell particles according to claim 1, characterized in that, After uniformly mixing the core-shell particle filler in Claim 1 with the polymer, perform compression molding to obtain the polymer matrix composite filled with the core-shell particles.

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