High-strength wear-resistant pet material and preparation method thereof

Abstract

This invention discloses a high-strength and wear-resistant PET material and its preparation method, belonging to the field of polymer materials technology. It aims to solve the technical problem of the difficulty in achieving a balance between high strength and high wear resistance in existing PET materials, and the unintended consequences of conventional modification methods. The PET material comprises the following components by weight: 60-80 parts PET resin, 10-25 parts glass fiber, 3-12 parts lubricating microspheres, 0.5-2 parts interface compatibilizer, 2-8 parts toughening agent, 0.2-0.8 parts nucleating agent, and 0.1-0.5 parts antioxidant. The lubricating microspheres are hollow mesoporous silica microspheres whose surfaces are sealed and modified with silane coupling agent KH570, and which are internally loaded with an ionic liquid lubricant. This invention achieves a synergistic improvement in the high strength and high wear resistance of the PET material through the functional decoupling design of the glass fiber and the lubricating microspheres, relying on the lubricant release mechanism triggered by the sliding of the microphase separation interface.

Description

Technical Field

[0001] This invention belongs to the field of polymer materials technology, and relates to a high-strength and wear-resistant PET material and its preparation method. Background Technology

[0002] Polyethylene terephthalate (PET) is a semi-crystalline thermoplastic polyester with high mechanical strength, chemical resistance, good electrical insulation, easy processing and molding, and recyclability. It is widely used in textile fibers, food packaging containers, electronic and electrical components, automotive structural parts, and functional films, and is one of the most produced general-purpose engineering plastics.

[0003] Under normal operating conditions, pure PET material can meet the performance requirements of general structural components and packaging containers. However, in high-end manufacturing, precision machinery, and automotive lightweighting, PET parts often need to operate under harsh conditions such as continuous friction and impact loads, placing higher demands on the material's synergistic performance of high strength and high wear resistance. Pure PET material has inherent defects such as low surface hardness, high coefficient of friction, and insufficient creep resistance: under repeated friction, the material surface is prone to shedding of wear debris, leading to loss of dimensional accuracy and shortened service life; under high load conditions, it is difficult to balance tensile strength and impact toughness, making deformation or brittle fracture likely. In addition, conventional reinforcement and modification methods often increase brittleness or deteriorate wear resistance while improving strength, making it difficult to achieve synergistic optimization of high strength and high wear resistance. Therefore, developing a PET material that combines high strength, high wear resistance, and good processing performance is of great practical significance for expanding its application in high-end engineering fields. Summary of the Invention

[0004] The purpose of this invention is to provide a high-strength and wear-resistant PET material and its preparation method, so as to solve the problem that the strength and wear resistance of existing PET materials are difficult to improve simultaneously under high load friction conditions, and to achieve excellent wear-resistant and self-lubricating properties while maintaining high mechanical strength.

[0005] The objective of this invention can be achieved through the following technical solutions:

[0006] In a first aspect, the present invention provides a high-strength and wear-resistant PET material, comprising the following components in parts by weight: 60-80 parts PET resin, 10-25 parts glass fiber, 3-12 parts lubricating microspheres, 0.5-2 parts interface compatibilizer, 2-8 parts toughening agent, 0.2-0.8 parts nucleating agent, and 0.1-0.5 parts antioxidant;

[0007] The lubricating microspheres are hollow mesoporous silica microspheres whose surfaces are sealed and modified with silane coupling agents, and whose internal cavities and mesoporous channels are loaded with ionic liquid lubricants.

[0008] Preferably, the preparation steps of the lubricating microspheres are as follows: under vacuum conditions, the dried hollow mesoporous silica microspheres are immersed in an ionic liquid, so that the ionic liquid is loaded into the cavity and mesoporous channels of the microspheres to obtain microspheres loaded with ionic liquid; then the microspheres loaded with ionic liquid are placed in a hydrolysate containing silane coupling agent KH570 and reacted at 50-60°C for 4-6 hours to construct a polysiloxane sealing layer on the surface of the microspheres, thus obtaining the lubricating microspheres.

[0009] Preferably, the hollow mesoporous silica microspheres have an average particle size of 1-5 μm, a specific surface area ≥500 m² / g, and a mesopore size of 2-10 nm.

[0010] Preferably, the ionic liquid is 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt.

[0011] Preferably, the glass fiber is alkali-free chopped glass fiber with a single filament diameter of 9-13 μm and a chopped length of 3-6 mm.

[0012] Preferably, the interface compatibilizer is silane coupling agent KH560.

[0013] Preferably, the toughening agent is an ethylene-methyl acrylate-glycidyl methacrylate terpolymer.

[0014] Preferably, the nucleating agent is nano-silica with an average particle size of 20-50 nm.

[0015] In a second aspect, the present invention provides a method for preparing a high-strength, wear-resistant PET material as described in the first aspect, comprising the following steps:

[0016] S1. Add the dried PET resin, lubricating microspheres, interface compatibilizer, toughening agent, nucleating agent and antioxidant to a high-speed mixer in proportion and mix evenly to obtain a premix.

[0017] S2. The premixed material is added to the main feed port of the twin-screw extruder, and the dried glass fiber is added from the side feed port of the twin-screw extruder for melt blending and extrusion. The extrusion temperature is controlled at 235-265℃ and the screw speed is 200-300rpm. After cooling and pelletizing, PET composite material granules are obtained.

[0018] S3. After drying the PET composite material granules, they are injection molded using an injection molding machine at an injection temperature of 260-275℃ and a mold temperature of 90-120℃ to obtain a high-strength and wear-resistant PET material.

[0019] Preferably, in step S1, the PET resin is dried under vacuum at 120-140°C for 6-8 hours to reduce its moisture content to less than 0.02%.

[0020] The beneficial effects of this invention are:

[0021] (1) This invention achieves a synergistic improvement in the high strength and high wear resistance of PET materials through the functional decoupling design of glass fiber reinforcement and lubricating microspheres. The glass fiber forms a three-dimensional skeleton in the matrix, bearing the load and endowing the material with excellent mechanical properties; the lubricating microspheres are independently responsible for the lubrication regulation of the friction interface. The physical isolation and functional division of labor between the two effectively solves the contradiction of difficulty in achieving both reinforcement and wear resistance in traditional modification technology, so that the obtained PET material has both high strength and excellent wear resistance and self-lubricating properties.

[0022] (2) The polysiloxane sealing layer on the surface of the lubricating microspheres of this invention has an essential difference in chemical polarity from the PET matrix—PET is a polar polyester, while polysiloxane is a highly hydrophobic nonpolar chain segment. This difference causes the two to spontaneously form a clear microphase separation interface during melt blending, that is, there is a relatively weak interface layer between the microsphere surface and the PET matrix. When the material is in a static or low-load state, the polysiloxane sealing layer tightly covers the pore openings of the hollow mesoporous silica microspheres, firmly sealing the ionic liquid lubricant in the internal cavity and mesoporous channels, preventing premature leakage or migration precipitation during storage and non-working states. When the material surface is subjected to frictional shearing, because the PET matrix is ​​a continuous phase with high cohesive strength, while the interfacial bonding energy between the polysiloxane sealing layer and the PET matrix is ​​much lower than the cohesive energy of the PET body, the shear stress preferentially selects the path of least resistance during transmission, that is, it is concentrated and released at the weak microphase separation interface, causing slippage at the interface. This interfacial slippage behavior pushes or peels away the polysiloxane sealing layer that originally covered the mesoporous channel openings, exposing the interconnected mesoporous channels. Driven by the local temperature rise generated during friction and the capillary action of the channels, the ionic liquid lubricant preloaded inside the microspheres is continuously transported to the friction interface, spreading in situ to form an extremely thin ion-adsorbed lubricating film, effectively separating the frictional surfaces and thus significantly reducing the coefficient of friction and wear rate. When friction stops and shear stress is removed, the polysiloxane segments undergo molecular chain movement under thermodynamic drive, re-covering the mesoporous channel openings, allowing the sealing layer to reset and closing the lubricant release channel. This reversible opening and closing characteristic of the sealing layer ensures that the lubricating microspheres can respond repeatedly in multiple friction cycles, realizing the "on-demand release" of the lubricant. Detailed Implementation

[0023] To further illustrate the technical means and effects of the present invention in achieving its intended purpose, the following detailed description of the specific implementation methods, structures, features, and effects of the present invention, in conjunction with embodiments, is provided below.

[0024] The following descriptions of some of the raw materials used in the examples and comparative examples are as follows:

[0025] The PET resin used is DuPont RE19050 from the United States;

[0026] The toughening agent is an ethylene-methyl acrylate-glycidyl methacrylate terpolymer, using Arkema AX8900 from France;

[0027] Except for the raw materials explicitly mentioned above, all other raw materials not specifically mentioned are conventional industrial-grade products that can be easily obtained through commercial channels.

[0028] Example 1

[0029] A high-strength, wear-resistant PET material is prepared from the following raw materials in parts by weight: 70 parts PET resin, 18 parts alkali-free chopped glass fiber (diameter 11μm, length 4.5mm), 6 parts lubricating microspheres, 1.2 parts interface compatibilizer KH560, 4 parts toughening agent (ethylene-methyl acrylate-glycidyl methacrylate terpolymer), 0.4 parts nucleating agent nano silica (average particle size 30nm), 0.3 parts antioxidant (1010 and 168 compounded in a 1:1 weight ratio), and 0.4 parts lubricating dispersant EBS.

[0030] The lubricating microspheres are prepared as follows:

[0031] A1. Take commercially available hollow mesoporous silica microspheres (average particle size 2μm, specific surface area 550 m²). 2 / g, mesopore size 5nm) 10g, vacuum dried at 120℃ for 4 hours;

[0032] A2. Under vacuum conditions, dried hollow mesoporous silica microspheres were immersed in 30g of ionic liquid (1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt), and the vacuum was maintained for 30 minutes. After restoring to normal pressure, the immersion was continued for 2 hours. After removal, the surface was quickly rinsed with anhydrous ethanol to obtain microspheres loaded with ionic liquid. The loading rate was determined by weighing to be approximately 35wt% (i.e., the ionic liquid accounted for 35% of the total mass of the loaded microspheres).

[0033] A3. All the microspheres loaded with ionic liquid obtained in step A2 were ultrasonically dispersed in KH570 hydrolysate at pH 4.5 (prepared by 100 mL anhydrous ethanol, 5 mL deionized water, and 2 g KH570, with pH adjusted to 4.5 by acetic acid). The mixture was stirred at 55 °C for 5 hours. After the reaction was completed, the mixture was centrifuged, washed with ethanol, and vacuum dried at 60 °C for 12 hours to obtain the lubricating microspheres.

[0034] The preparation method of high-strength and wear-resistant PET material is as follows:

[0035] S1. Vacuum dry PET resin at 130℃ for 7 hours to reduce its moisture content to below 0.02%; dry lubricating microspheres and nano-silica at 90℃ for 3 hours; dry glass fiber at 80℃ for 1.5 hours.

[0036] S2. Add the dried PET resin, lubricating microspheres, KH560, toughening agent, nano silica, antioxidant and EBS to a high-speed mixer according to the above weight proportions, and mix at 800 rpm for 8 minutes to obtain a premix.

[0037] S3. The premixed material is added to the main feed port of a twin-screw extruder with a length-to-diameter ratio of 36:1. Glass fiber is separately metered and added from the side feed port (located at 2 / 3 of the total screw length) for melt blending extrusion. Extrusion process parameters: feeding section 240℃, plasticizing section 255℃, metering section 260℃, die head 255℃, screw speed 250rpm, vacuum degree -0.09 MPa. The extrudate is cooled in a water bath, air-dried, and pelletized to obtain PET composite material pellets.

[0038] S4. The obtained granules are vacuum dried at 130℃ for 5 hours, and then injection molded using an injection molding machine. Injection molding process parameters: injection temperature 268℃, mold temperature 105℃, injection pressure 80 MPa, holding pressure 50 MPa, holding time 10 seconds, cooling time 20 seconds, to obtain high-strength and wear-resistant PET material.

[0039] Example 2

[0040] A high-strength, wear-resistant PET material is prepared from the following raw materials in parts by weight: 75 parts PET resin, 15 parts alkali-free chopped glass fiber (10 μm in diameter and 3 mm in length), 5 parts lubricating microspheres, 1.0 part interface compatibilizer KH560, 3 parts toughening agent (ethylene-methyl acrylate-glycidyl methacrylate terpolymer), 0.3 parts nucleating agent nano silica (average particle size 25 nm), 0.2 parts antioxidant (1010 and 168 compounded in a 1:1 weight ratio), and 0.3 parts lubricating dispersant EBS.

[0041] The lubricating microspheres are prepared as follows:

[0042] A1. Take commercially available hollow mesoporous silica microspheres (average particle size 1μm, specific surface area 520 m²). 2 / g, mesopore size 3nm) 10g, vacuum dried at 120℃ for 4 hours;

[0043] A2. Under vacuum conditions, dried hollow mesoporous silica microspheres were immersed in 30g of ionic liquid (1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt). The vacuum was maintained for 30 minutes, and after restoring to normal pressure, the immersion continued for 2 hours. The microspheres were then removed and rapidly rinsed with anhydrous ethanol to obtain microspheres loaded with the ionic liquid. The loading rate was determined to be approximately 35 wt% by weighing.

[0044] A3. All the microspheres loaded with ionic liquid obtained in step A2 were ultrasonically dispersed in KH570 hydrolysate at pH=4 (prepared by 100mL anhydrous ethanol, 5mL deionized water, and 2g KH570, with pH adjusted to 4 by acetic acid). The mixture was stirred at 50℃ for 4 hours. After the reaction was completed, the mixture was centrifuged, washed with ethanol, and vacuum dried at 60℃ for 12 hours to obtain the lubricating microspheres.

[0045] The preparation method of high-strength and wear-resistant PET material is as follows:

[0046] S1. Vacuum dry PET resin at 120℃ for 8 hours to reduce its moisture content to below 0.02%; dry lubricating microspheres and nano-silica at 80℃ for 4 hours; dry glass fiber at 80℃ for 2 hours.

[0047] S2. Add the dried PET resin, lubricating microspheres, KH560, toughening agent, nano silica, antioxidant and EBS to a high-speed mixer according to the above weight proportions, and mix at 500 rpm for 10 minutes to obtain a premix.

[0048] S3. The premixed material is added to the main feed port of a twin-screw extruder with a length-to-diameter ratio of 32:1. Glass fiber is separately metered and added from the side feed port for melt blending and extrusion. Extrusion process parameters: feeding section 235℃, plasticizing section 250℃, metering section 255℃, die head 250℃, screw speed 200rpm, vacuum degree -0.08 MPa. The extrudate is cooled in a water bath, air-dried, and pelletized to obtain PET composite material pellets.

[0049] S4. The obtained granules are vacuum dried at 120℃ for 6 hours, and then injection molded using an injection molding machine. Injection molding process parameters: injection temperature 260℃, mold temperature 90℃, injection pressure 60 MPa, holding pressure 40 MPa, holding time 5 seconds, cooling time 15 seconds, to obtain high-strength and wear-resistant PET material.

[0050] Example 3

[0051] A high-strength, wear-resistant PET material is prepared from the following raw materials in parts by weight: 65 parts PET resin, 20 parts alkali-free chopped glass fiber (13 μm in diameter and 6 mm in length), 8 parts lubricating microspheres, 1.5 parts interface compatibilizer KH560, 5 parts toughening agent (ethylene-methyl acrylate-glycidyl methacrylate terpolymer), 0.5 parts nucleating agent nano-silica (average particle size 40 nm), 0.3 parts antioxidant (1010 and 168 compounded in a 1:1 weight ratio), and 0.5 parts lubricating dispersant EBS.

[0052] The lubricating microspheres are prepared as follows:

[0053] A1. Take commercially available hollow mesoporous silica microspheres (average particle size 5μm, specific surface area 580 m²). 2 / g, mesopore size 8nm) 10g, vacuum dried at 120℃ for 4 hours;

[0054] A2. Under vacuum conditions, dried hollow mesoporous silica microspheres were immersed in 30g of ionic liquid (1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt). The vacuum was maintained for 30 minutes, and after restoring to normal pressure, the immersion continued for 2 hours. The microspheres were then removed and rapidly rinsed with anhydrous ethanol to obtain the ionic liquid-loaded microspheres. The loading rate was determined to be approximately 35 wt% by weighing.

[0055] A3. All the microspheres loaded with ionic liquid obtained in step A2 were ultrasonically dispersed in KH570 hydrolysate at pH=5 (prepared by 100mL anhydrous ethanol, 5mL deionized water, and 2g KH570, with pH adjusted to 5 by acetic acid). The mixture was stirred at 60℃ for 6 hours. After the reaction was completed, the mixture was centrifuged, washed with ethanol, and vacuum dried at 60℃ for 12 hours to obtain the lubricating microspheres.

[0056] The preparation method of high-strength and wear-resistant PET material is as follows:

[0057] S1. Vacuum dry PET resin at 140℃ for 6 hours to reduce its moisture content to below 0.02%; dry lubricating microspheres and nano-silica at 100℃ for 2 hours; dry glass fiber at 80℃ for 1 hour.

[0058] S2. Add the dried PET resin, lubricating microspheres, KH560, toughening agent, nano silica, antioxidant and EBS to a high-speed mixer according to the above weight proportions, and mix at 1000 rpm for 5 minutes to obtain a premix.

[0059] S3. The premixed material is added to the main feed port of a twin-screw extruder with a length-to-diameter ratio of 40:1. Glass fiber is separately metered and added from the side feed port for melt blending and extrusion. Extrusion process parameters: feeding section 245℃, plasticizing section 260℃, metering section 265℃, die head 255℃, screw speed 300rpm, vacuum degree -0.09 MPa. The extrudate is cooled in a water bath, air-dried, and pelletized to obtain PET composite material pellets.

[0060] S4. The obtained granules are vacuum dried at 140℃ for 4 hours, and then injection molded using an injection molding machine. Injection molding process parameters: injection temperature 275℃, mold temperature 120℃, injection pressure 100 MPa, holding pressure 60 MPa, holding time 15 seconds, cooling time 30 seconds, to obtain high-strength and wear-resistant PET material.

[0061] Comparative Example 1

[0062] The difference from Example 1 is that glass fiber is not added to the raw materials of the high-strength and wear-resistant PET material, while the other components, proportions and preparation methods are the same as in Example 1.

[0063] Comparative Example 2

[0064] The difference from Example 1 is that no lubricating microspheres are added to the raw materials of the high-strength and wear-resistant PET material, while the other components, proportions and preparation methods are the same as in Example 1.

[0065] Comparative Example 3

[0066] The difference from Example 1 is that the lubricating microspheres used are hollow mesoporous silica microspheres loaded with ionic liquid that have not undergone KH570 sealing treatment. That is, the preparation of the lubricating microspheres only involves steps A1 and A2, omitting the surface polysiloxane sealing layer construction step A3. The remaining components, proportions, and preparation methods are the same as in Example 1.

[0067] Comparative Example 4

[0068] The difference from Example 1 is that lubricating microspheres are not used; instead, an equal mass of ionic liquid is added directly as a lubricant component. Specifically, the 6 parts of lubricating microspheres in Example 1 are omitted, and 2.1 parts of ionic liquid (1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt) are added directly to the S2 premix. All other components, proportions, and preparation methods are the same as in Example 1.

[0069] test

[0070] The PET materials prepared in Examples 1-3 and Comparative Examples 1-4 were used to make standard test strips under the same injection molding process conditions, and their performance was tested according to the following methods:

[0071] 1. Mechanical property testing

[0072] Tensile strength: Tested according to GB / T 1040.2-2006, tensile rate 50 mm / min.

[0073] Bending strength: Tested according to GB / T 9341-2008, span 64 mm, test speed 2 mm / min.

[0074] Notched impact strength: Tested according to GB / T 1043.1-2008, at room temperature, type A notch.

[0075] 2. Tribological and Wear Performance Testing

[0076] Friction coefficient and volumetric wear rate: Tested according to GB / T 3960-2016 using a pin-disc friction and wear testing machine. The mating part was a 45# steel pin, 6mm in diameter, with a spherical radius of 10mm at the end and a surface roughness Ra=0.4μm. Test conditions: load 200N, rotation speed 200r / min (corresponding to a sliding speed of approximately 0.42m / s), running time 2h. The friction torque was recorded in real time by computer and the average friction coefficient was calculated; the wear rate was calculated by the difference in sample mass and density before and after the test.

[0077] The test results are shown in Table 1.

[0078]

[0079] Results analysis:

[0080] (1) As can be seen from the comparison between Examples 1-3 and Comparative Example 1, when no glass fiber was added (Comparative Example 1), the tensile strength of the material decreased from 136 MPa to 88 MPa and the flexural strength decreased from 198 MPa to 121 MPa, with a significant decrease. The notched impact strength also decreased significantly. This indicates that the three-dimensional interwoven skeleton formed by glass fiber in the matrix is ​​the main reinforcing phase that bears the external load, and the absence of glass fiber will lead to a significant deterioration in the mechanical properties of the material.

[0081] (2) As can be seen from the comparison between Examples 1-3 and Comparative Example 2, when no lubricating microspheres were added (Comparative Example 2), although the mechanical properties of the material remained good due to the presence of glass fiber, the coefficient of friction was as high as 0.42, and the volumetric wear rate was more than 5 times that of Example 1. This shows that simply relying on reinforcement modification cannot improve the friction and wear performance of PET materials. The lubricating microspheres of the present invention are the decisive functional component for achieving high wear resistance and self-lubricating properties.

[0082] (3) As can be seen from the comparison between Example 1 and Comparative Example 3, when the lubricating microspheres were not sealed and modified with KH570 (Comparative Example 3), due to the open mesoporous channels, some ionic liquids escaped prematurely during the processing and storage stages. As a result, although the coefficient of friction and wear rate were improved compared with Comparative Example 2, they were still significantly worse than those of Example 1. This verifies that the sealing and protection of the lubricant and the on-demand release mechanism of the polysiloxane sealing layer are necessary guarantees for achieving long-term wear resistance.

[0083] (4) As can be seen from the comparison between Example 1 and Comparative Example 4, when ionic liquid is directly added externally (Comparative Example 4), the material friction coefficient and wear rate are higher than those in Example 1 due to the poor compatibility between the ionic liquid and the PET matrix and its easy migration and precipitation. At the same time, the notched impact strength is reduced, reflecting the plasticizing and weakening effect of small molecule lubricant on the matrix. This result fully demonstrates that pre-encapsulating ionic liquid inside hollow mesoporous microspheres can effectively avoid uneven processing dispersion and matrix performance loss, which is the key to achieving synergistic optimization of high strength and high wear resistance.

[0084] In summary, this invention, through the functional decoupling design of glass fiber and sealing lubricating microspheres and relying on the on-demand release mechanism triggered by the sliding of the microphase separation interface, successfully solves the contradiction between strength and wear resistance in traditional PET modification, and achieves a synergistic improvement in high strength and high wear resistance.

[0085] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A high-strength, wear-resistant PET material, characterized in that, It includes the following components in parts by weight: 60-80 parts PET resin, 10-25 parts glass fiber, 3-12 parts lubricating microspheres, 0.5-2 parts interface compatibilizer, 2-8 parts toughening agent, 0.2-0.8 parts nucleating agent, and 0.1-0.5 parts antioxidant; The lubricating microspheres are hollow mesoporous silica microspheres whose surfaces are sealed and modified with silane coupling agents, and whose internal cavities and mesoporous channels are loaded with ionic liquid lubricants.

2. The high-strength, wear-resistant PET material according to claim 1, characterized in that, The preparation steps of the lubricating microspheres are as follows: Under vacuum conditions, the dried hollow mesoporous silica microspheres are immersed in an ionic liquid, so that the ionic liquid is loaded into the cavity and mesoporous channels of the microspheres to obtain microspheres loaded with ionic liquid; then the microspheres loaded with ionic liquid are placed in a hydrolysate containing silane coupling agent KH570 and reacted at 50-60℃ for 4-6 hours to construct a polysiloxane sealing layer on the surface of the microspheres, thus obtaining the lubricating microspheres.

3. A high-strength, wear-resistant PET material according to claim 1 or 2, characterized in that, The hollow mesoporous silica microspheres have an average particle size of 1-5 μm, a specific surface area ≥500 m² / g, and a mesopore size of 2-10 nm.

4. A high-strength, wear-resistant PET material according to claim 1 or 2, characterized in that, The ionic liquid is 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt.

5. The high-strength, wear-resistant PET material according to claim 1, characterized in that, The glass fiber is alkali-free chopped glass fiber with a single filament diameter of 9-13μm and a chopped length of 3-6mm.

6. The high-strength, wear-resistant PET material according to claim 1, characterized in that, The interface compatibilizer is silane coupling agent KH560.

7. The high-strength, wear-resistant PET material according to claim 1, characterized in that, The toughening agent is an ethylene-methyl acrylate-glycidyl methacrylate terpolymer.

8. The high-strength, wear-resistant PET material according to claim 1, characterized in that, The nucleating agent is nano-silica with an average particle size of 20-50 nm.

9. A method for preparing a high-strength, wear-resistant PET material as described in any one of claims 1-8, characterized in that, Includes the following steps: S1. Add the dried PET resin, lubricating microspheres, interface compatibilizer, toughening agent, nucleating agent and antioxidant to a high-speed mixer in proportion and mix evenly to obtain a premix. S2. The premixed material is added to the main feed port of the twin-screw extruder, and the dried glass fiber is added from the side feed port of the twin-screw extruder for melt blending and extrusion. The extrusion temperature is controlled at 235-265℃ and the screw speed is 200-300rpm. After cooling and pelletizing, PET composite material granules are obtained. S3. After drying the PET composite material granules, they are injection molded using an injection molding machine at an injection temperature of 260-275℃ and a mold temperature of 90-120℃ to obtain a high-strength and wear-resistant PET material.

10. The method for preparing the high-strength, wear-resistant PET material according to claim 9, characterized in that, In step S1, the PET resin is dried under vacuum at 120-140°C for 6-8 hours to reduce its moisture content to less than 0.02%.

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