High-dispersion master batch modified ultra-high molecular weight polyethylene and preparation method thereof

Abstract

The invention relates to the technical field of high polymer material processing, in particular to high-dispersion master batch modified ultra-high molecular weight polyethylene and a preparation method thereof. The high-dispersion master batch modified ultra-high molecular weight polyethylene comprises the following raw materials in parts by mass: 82-93 parts of carrier resin; 0.5 to 5 parts of a lubricant; 0.3 to 1 part of an antioxidant; 1-2 parts of a nucleating agent; 2-5 parts of a heat conduction material; 3-5 parts of a reinforcing material; the heat conduction material is silicon carbide or aluminum nitride powder; and the reinforcing material is one of glass fiber powder or carbon nanotubes. According to the invention, uniform dispersion of the auxiliary agent is realized through the high-filling master batch, the problems of poor fluidity, large shrinkage distortion and easy precipitation of the auxiliary agent in the traditional process are solved, and the high strength and wear resistance of UHMWPE are maintained at the same time.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of high polymer material processing, in particular to high dispersion master batch modified ultra-high molecular weight polyethylene and a preparation method thereof. BACKGROUND

[0002] Ultra-high molecular weight polyethylene (UHMWPE, molecular weight usually > 1 million) is widely used in medical devices, mining machinery and other fields due to its excellent wear resistance, impact resistance and chemical stability. However, the melt viscosity of UHMWPE is extremely high (melt flow index MFI close to 0), making it difficult to be molded by conventional melt processing (such as injection molding, extrusion). Traditional modification methods usually adopt the following two ways: (1) Direct blending of additives, directly mixing lubricants, reinforcing agents and other additives with UHMWPE powder, but due to its poor melt flowability, the additives are not uniformly dispersed, leading to agglomeration, interface defects, and significant decrease in mechanical properties (such as tensile strength loss > 30%). (2) Low molecular weight carrier premixing, using low molecular weight polyethylene (such as LDPE, molecular weight < 100,000) as an additive carrier, but due to its poor compatibility with UHMWPE, phase separation occurs after processing, leading to performance degradation due to additive precipitation.

[0003] Defects of prior art: poor dispersion of additives, low efficiency of functional modification; poor compatibility of carrier with UHMWPE, poor long-term stability; high processing temperature (> 300℃), leading to material oxidation degradation.

[0004] Chinese patent application CN113736159A, published on December 3, 2021, discloses an ultra-high molecular weight polyethylene (UHMWPE) pipe and its preparation method. The formulation includes low molecular weight polyethylene (10-20 parts), graphene (0.1-0.6 parts), polyethylene wax, and other additives. By controlling the mixing temperature (130-140℃), the processing performance of the UHMWPE pipe is improved. Graphene enhances thermal conductivity, polyethylene wax improves lubricity, and the extrusion stability of the pipe is enhanced, making it suitable for industrial pipelines and wear-resistant liners. However, high filler content (such as graphene) may increase costs, and the problem of high-temperature oxidative degradation of UHMWPE is not solved. Chinese patent application CN1252168C, published on April 19, 2006, discloses a new method for improving the processing rheological properties of ultra-high molecular weight polyethylene. It adds 1%-10% of hyperbranched polyester-amide polymer, and through high-shear mixing (180-280℃), significantly reduces the melt viscosity of UHMWPE (torque reduction of 85%), improving fluidity. Hyperbranched polymers, with their three-dimensional structure, reduce molecular chain entanglement, making them suitable for injection molding and extrusion molding with significantly improved processing efficiency. However, hyperbranched polymers are costly and difficult to mass-produce industrially; long-term stability verification of mechanical properties is not addressed. Chinese patent application CN107739463A, published on February 27, 2018, uses a blend of 75% UHMWPE and 25% HDPE, adding pyrolytic silica nucleating agent (1 part) and zinc stearate lubricant (0.5 parts) to improve processing fluidity. HDPE acts as a carrier resin to enhance melt flowability; the nucleating agent optimizes the crystal structure and reduces shrinkage deformation. However, it offers limited improvement in abrasion resistance and impact resistance; the formulation is simple, and the technological barriers are relatively low. Summary of the Invention

[0005] In view of the shortcomings of the prior art, the purpose of this invention is to provide a highly dispersed masterbatch-modified ultra-high molecular weight polyethylene with significantly improved mechanical properties and high stability.

[0006] Another objective of this invention is to provide a method for preparing highly dispersed masterbatch-modified ultra-high molecular weight polyethylene (UHMWPE). By using highly filled masterbatch, the additives are uniformly dispersed, solving the problems of poor flowability, large shrinkage deformation, and easy precipitation of additives in traditional processes, while maintaining the high strength and wear resistance of UHMWPE.

[0007] This invention is achieved using the following technical solution: The highly dispersed masterbatch modified ultra-high molecular weight polyethylene comprises the following raw materials in parts by weight: carrier resin: 82-93 parts; lubricant: 0.5-5 parts; antioxidant: 0.3-1 parts; nucleating agent: 1-2 parts; thermally conductive material: 2-5 parts; reinforcing material: 3-5 parts; wherein the thermally conductive material is silicon carbide or aluminum nitride powder; and the reinforcing material is one of glass fiber powder or carbon nanotubes.

[0008] The carrier resin is medium-to-high molecular weight polyethylene with a molecular weight of 500,000-600,000; the lubricant is one or more of calcium stearate, oxidized polyethylene wax, or coupling agent-modified nano-SiO2; the antioxidant is a mixture of high molecular weight hindered phenolic antioxidant and phosphite antioxidant in a mass ratio of 1:2; the nucleating agent is nano-boron nitride with a particle size of 80-200 nm. The preferred high molecular weight hindered phenolic antioxidant is antioxidant 1010, and the preferred phosphite antioxidant is phosphite antioxidant 626.

[0009] The preparation method of the highly dispersed masterbatch modified ultra-high molecular weight polyethylene includes the following steps: (1) Low temperature premixing: Under nitrogen protection, the carrier resin, lubricant, antioxidant, nucleating agent, thermal conductive material and reinforcing material are added to the internal mixer at an initial temperature of 200-250℃ and a rotation speed of 30-60r / min. (2) High-temperature high-speed dispersion: raise the temperature to 280-300℃ and increase the rotation speed to 200-300r / min; (3) Extrusion granulation: The melt after internal mixing is transferred to a twin-screw extruder, and then melt-extruded, water-cooled and pelletized to obtain masterbatch; (4) The masterbatch is crushed by an air jet mill or a ball mill to obtain powder; (5) Dry mix the masterbatch powder and high molecular weight polyethylene (UHMWPE) at a mass ratio of (1-3): (7-9), and then obtain highly dispersed masterbatch modified ultra-high molecular weight polyethylene by molding, extrusion or injection molding.

[0010] In step (1), the mixing time is 10-20 min; in step (2), the mixing time is 3-5 min.

[0011] In step (3), the twin-screw extruder has a length-to-diameter ratio of 40:1 and a temperature zone of 200-260℃.

[0012] In step (5), the dry mixing is carried out using a high-speed mixer with a speed of 500-1000 r / min for 10-15 min.

[0013] In step (5), the molding pressure is 10-20 MPa and the temperature is 220-240℃.

[0014] Compared with the prior art, the beneficial effects of the present invention are: (1) Processing performance optimization: The high flowability carrier resin (MFI>1g / 10min) in the masterbatch reduces the overall melt viscosity of UHMWPE, and the injection molding temperature is reduced to 220-240℃ (the traditional process requires 260-300℃); the melt flow index (MFI) is increased to 0.5-1.2g / 10min, which meets the molding requirements of complex products.

[0015] (2) Significantly improved mechanical properties: shrinkage rate <0.8% (traditional process >1.5%), warpage reduced by more than 50%; tensile strength ≥35MPa (pure UHMWPE about 30MPa), wear rate <3×10⁻ 6 mm³ / N•m.

[0016] (3) The stability of the additives is greatly improved: After the additives in the masterbatch are dispersed under high shear, there is no migration or precipitation in the UHMWPE matrix (no precipitates on the surface after aging at 85℃ for 1000h); the nanofillers are evenly dispersed. Detailed Implementation

[0017] To make the objectives and technical solutions of this invention clearer, the invention will be further described in detail below.

[0018] Manufacturers of each raw material: Medium and high molecular weight polyethylene: Qilu Branch of China Petroleum & Chemical Corporation, QHM22F (MFI=1.5). Oxidized polyethylene wax: Clariant Chemicals (China) Co., Ltd., Licowax PE520; Antioxidant 1010: Sanfeng Chemical Co., Ltd., Linyi City, Shandong Province; Antioxidant 626: Sanfeng Chemical Co., Ltd., Linyi City, Shandong Province; Nano boron nitride: Suzhou Napo Materials Technology Co., Ltd., XF80-120, particle size 80-200nm; Silicon carbide: Yumu (Ningbo) New Materials Co., Ltd., YM-SiC-02W, (D50=2μm); Aluminum nitride: Nanjing Boket New Materials Co., Ltd., PAT-G05A (particle size 50nm); Carbon nanotubes: Jiangsu Tiannai Technology Co., Ltd., FT9000 (multi-walled tube, 10nm diameter); Glass fiber powder: Hebei Tianhuibao Technology Co., Ltd., THB-BXF08; Nano SiO2: Hubei Huifu Nanomaterials Co., Ltd., HB-132.

[0019] Test method: Melt Flow Index (MFI) Test: GB / T 3682.1-2018 "Determination of Melt Mass Flow Rate (MFR) and Melt Volume Flow Rate (MVR) of Thermoplastic Plastics - Part 1: Standard Method"; Thermal conductivity test: GB / T 10294-2008 "Determination of steady-state thermal resistance and related properties of thermal insulation materials - protective hot plate method"; Shrinkage test: GB / T 17037.4-2003 "Preparation of injection molded specimens of thermoplastic materials - Part 4: Determination of molding shrinkage"; Tensile strength test: GB / T 1040.1-2018 "Determination of tensile properties of plastics - Part 1".

[0020] Example 1 Highly dispersed masterbatch modified ultra-high molecular weight polyethylene comprises the following raw materials in parts by weight: carrier resin: 85 parts; lubricant: 5 parts; antioxidant: 0.5 parts; nucleating agent: 1 part; thermally conductive material: 5 parts; reinforcing material: 3 parts; the thermally conductive material is silicon carbide with D50=2μm; the reinforcing material is glass fiber powder with a diameter of 10μm.

[0021] The carrier resin is medium-high molecular weight polyethylene with a molecular weight of 550,000; the lubricant is calcium stearate and oxidized polyethylene wax in a mass ratio of 1:1; the antioxidant is antioxidant 1010 and antioxidant 626 in a mass ratio of 1:2; and the nucleating agent is nano boron nitride with a particle size of 80 nm.

[0022] A method for preparing highly dispersed masterbatch-modified ultra-high molecular weight polyethylene includes the following steps: (1) Low temperature premixing: Under nitrogen protection, the carrier resin, lubricant, antioxidant, nucleating agent, thermal conductive material and reinforcing material are added to the internal mixer at an initial temperature of 250℃ and a rotation speed of 50r / min. (2) High-temperature high-speed dispersion: Heat to 290℃ and increase rotation speed to 250r / min; (3) Extrusion granulation: The melt after internal mixing is transferred to a twin-screw extruder, and then melt-extruded, water-cooled and pelletized to obtain masterbatch; (4) The masterbatch is crushed by an air jet mill or a ball mill to obtain powder with D50=100μm; (5) Dry mix the masterbatch powder and UHMWPE at a mass ratio of 2:8, and then obtain highly dispersed masterbatch modified ultra-high molecular weight polyethylene by molding, extrusion or injection molding.

[0023] In step (1), the mixing time is 15 min; in step (2), the mixing time is 4 min; in step (3), the length-to-diameter ratio of the twin-screw extruder is 40:1, and the temperature zones from the feed port to the die head are 200℃, 220℃, 240℃, 250℃, and 260℃, with a rotation speed of 200 r / min. In step (5), the dry mixing is carried out using a high-speed mixer with a rotation speed of 800 r / min for 12 min; the molding pressure is 15 MPa, and the temperature is 220℃.

[0024] Example 2 Highly dispersed masterbatch modified ultra-high molecular weight polyethylene comprises the following raw materials in parts by weight: carrier resin: 82 parts; lubricant: 0.5 parts; antioxidant: 0.3 parts; nucleating agent: 1 part; thermally conductive material: 2 parts; reinforcing material: 3 parts; the thermally conductive material is silicon carbide with D50=2μm; the reinforcing material is glass fiber powder with a diameter of 10μm.

[0025] The carrier resin is medium-high molecular weight polyethylene with a molecular weight of 500,000; the lubricant is calcium stearate; the antioxidant is a mixture of antioxidant 1010 and 626 in a mass ratio of 1:2; and the nucleating agent is nano boron nitride with a particle size of 100 nm.

[0026] A method for preparing highly dispersed masterbatch-modified ultra-high molecular weight polyethylene includes the following steps: (1) Low temperature premixing: Under nitrogen protection, the carrier resin, lubricant, antioxidant, nucleating agent, thermal conductive material and reinforcing material are added to the internal mixer at an initial temperature of 200℃ and a rotation speed of 30r / min. (2) High-temperature high-speed dispersion: Heat to 280℃ and increase rotation speed to 200r / min; (3) Extrusion granulation: The melt after internal mixing is transferred to a twin-screw extruder, and then melt-extruded, water-cooled and pelletized to obtain masterbatch; (4) The masterbatch is crushed by an air jet mill or a ball mill to obtain powder; (5) Dry mix the masterbatch powder and UHMWPE at a mass ratio of 1:9, and then obtain highly dispersed masterbatch modified ultra-high molecular weight polyethylene by molding, extrusion or injection molding.

[0027] In step (1), the mixing time is 10 min; in step (2), the mixing time is 3 min; in step (3), the length-to-diameter ratio of the twin-screw extruder is 40:1, and the temperature zones from the feed port to the die head are 200℃, 220℃, 240℃, 250℃, and 260℃ respectively; in step (5), the dry mixing is carried out using a high-speed mixer with a speed of 500 r / min and a mixing time of 10 min; in step (5), the molding pressure is 10 MPa and the temperature is 220℃.

[0028] Example 3 Highly dispersed masterbatch modified ultra-high molecular weight polyethylene comprises the following raw materials in parts by weight: carrier resin: 93 parts; lubricant: 5 parts; antioxidant: 1 part; nucleating agent: 2 parts; thermally conductive material: 5 parts; reinforcing material: 5 parts; the thermally conductive material is aluminum nitride powder; the reinforcing material is carbon nanotubes.

[0029] The carrier resin is medium-to-high molecular weight polyethylene with a molecular weight of 600,000; the lubricant is oxidized polyethylene wax; the antioxidant is a mixture of antioxidant 1010 and antioxidant 626 in a mass ratio of 1:2; and the nucleating agent is nano boron nitride with a particle size of 100 nm.

[0030] A method for preparing highly dispersed masterbatch-modified ultra-high molecular weight polyethylene includes the following steps: (1) Low temperature premixing: Under nitrogen protection, the carrier resin, lubricant, antioxidant, nucleating agent, thermal conductive material and reinforcing material are added to the internal mixer at an initial temperature of 250℃ and a rotation speed of 60r / min. (2) High-temperature high-speed dispersion: Heat to 300℃ and increase rotation speed to 300r / min; (3) Extrusion granulation: The melt after internal mixing is transferred to a twin-screw extruder, and then melt-extruded, water-cooled and pelletized to obtain masterbatch; (4) The masterbatch is crushed by an air jet mill or a ball mill to obtain powder; (5) Dry mix the masterbatch powder and UHMWPE at a mass ratio of 3:7, and then obtain highly dispersed masterbatch modified ultra-high molecular weight polyethylene by molding, extrusion or injection molding.

[0031] In step (1), the mixing time is 20 min; in step (2), the mixing time is 5 min; in step (3), the length-to-diameter ratio of the twin-screw extruder is 40:1, and the temperature zones from the feed port to the die head are 200℃, 220℃, 240℃, 250℃, and 260℃ respectively; in step (5), the dry mixing is carried out using a high-speed mixer with a speed of 1000 r / min and a mixing time of 15 min; in step (5), the molding pressure is 20 MPa and the temperature is 240℃.

[0032] Example 4 Highly dispersed masterbatch modified ultra-high molecular weight polyethylene comprises the following raw materials in parts by weight: carrier resin: 82 parts; lubricant: 4 parts; antioxidant: 0.8 parts; nucleating agent: 2 parts; thermally conductive material: 4 parts; reinforcing material: 5 parts; the thermally conductive material is aluminum nitride powder; the reinforcing material is carbon nanotubes.

[0033] The carrier resin is medium-high molecular weight polyethylene with a molecular weight of 580,000; the lubricant is coupling agent modified nano-SiO2; the antioxidant is antioxidant 1010 and antioxidant 626 compounded in a mass ratio of 1:2; and the nucleating agent is nano-boron nitride with a particle size of 100nm.

[0034] A method for preparing highly dispersed masterbatch-modified ultra-high molecular weight polyethylene includes the following steps: (1) Low temperature premixing: Under nitrogen protection, the carrier resin, lubricant, antioxidant, nucleating agent, thermal conductive material and reinforcing material are added to the internal mixer at an initial temperature of 240℃ and a rotation speed of 35r / min. (2) High-temperature high-speed dispersion: Heat to 300℃ and increase rotation speed to 280r / min; (3) Extrusion granulation: The melt after internal mixing is transferred to a twin-screw extruder, and then melt-extruded, water-cooled and pelletized to obtain masterbatch; (4) The masterbatch is crushed by an air jet mill or a ball mill to obtain powder; (5) Dry mix the masterbatch powder and UHMWPE at a mass ratio of 2:8, and then obtain highly dispersed masterbatch modified ultra-high molecular weight polyethylene by molding, extrusion or injection molding.

[0035] In step (1), the mixing time is 20 min; in step (2), the mixing time is 5 min; in step (3), the length-to-diameter ratio of the twin-screw extruder is 40:1, and the temperature zones from the feed port to the die head are 200℃, 220℃, 240℃, 250℃, and 260℃, with a rotation speed of 200 r / min; in step (5), the dry mixing is carried out using a high-speed mixer with a rotation speed of 700 r / min and a mixing time of 12 min; in step (5), the molding pressure is 13 MPa and the temperature is 230℃.

[0036] Example 5 Highly dispersed masterbatch modified ultra-high molecular weight polyethylene comprises the following raw materials in parts by weight: carrier resin: 82 parts; lubricant: 1 part; antioxidant: 0.6 parts; nucleating agent: 1 part; thermally conductive material: 3 parts; reinforcing material: 5 parts; the thermally conductive material is silicon carbide; the reinforcing material is glass fiber powder.

[0037] The carrier resin is medium-high molecular weight polyethylene with a molecular weight of 500,000; the lubricant is oxidized polyethylene wax and coupling agent modified nano-SiO2 with a mass ratio of 1:1; the antioxidant is antioxidant 1010 and antioxidant 626 compounded in a mass ratio of 1:2; the nucleating agent is nano-boron nitride with a particle size of 120nm.

[0038] A method for preparing highly dispersed masterbatch-modified ultra-high molecular weight polyethylene includes the following steps: (1) Low temperature premixing: Under nitrogen protection, the carrier resin, lubricant, antioxidant, nucleating agent, thermal conductive material and reinforcing material are added to the internal mixer at an initial temperature of 230℃ and a rotation speed of 40r / min. (2) High-temperature high-speed dispersion: The temperature is raised to 285℃ and the rotation speed is increased to 300r / min; (3) Extrusion granulation: The melt after internal mixing is transferred to a twin-screw extruder, and then melt-extruded, water-cooled and pelletized to obtain masterbatch; (4) The masterbatch is crushed by an air jet mill or a ball mill to obtain powder; (5) Dry mix the masterbatch powder and UHMWPE at a mass ratio of 2:8, and then obtain highly dispersed masterbatch modified ultra-high molecular weight polyethylene by molding, extrusion or injection molding.

[0039] In step (1), the mixing time is 20 min; in step (2), the mixing time is 5 min; in step (3), the length-to-diameter ratio of the twin-screw extruder is 40:1, and the temperature zones from the feed port to the die head are 200℃, 220℃, 240℃, 250℃, and 260℃ respectively; in step (5), the dry mixing is carried out using a high-speed mixer with a speed of 550 r / min and a mixing time of 15 min; in step (5), the molding pressure is 20 MPa and the temperature is 230℃.

[0040] Comparative Example 1 The difference from Example 1 is that pure UHMWPE was used for testing.

[0041] Comparative Example 2 The difference from Example 1 is that no nucleating agent was added.

[0042] Comparative Example 3 The difference from Example 1 is that no thermally conductive material was added.

[0043] The test data for Examples 1-5 and Comparative Examples 1-3 are shown in Table 1.

[0044] Table 1: Test data of Examples 1-5 and Comparative Examples 1-3

[0045] Based on the test data from Examples 1-5 and Comparative Examples 1-3, the highly dispersed masterbatch-modified ultra-high molecular weight polyethylene of the present invention exhibits excellent performance in multiple aspects. Regarding flowability, the melt flow index (MFI) of the examples reached 0.5–1.2 g / 10 min, significantly higher than the 0.02 g / 10 min of pure ultra-high molecular weight polyethylene in Comparative Example 1. In Example 3, due to its high carrier resin content and masterbatch addition of 30%, the highest MFI was 1.2 g / 10 min, indicating that the carrier resin in the masterbatch effectively reduces the melt viscosity of ultra-high molecular weight polyethylene. Simultaneously, the added lubricant interacts with it, further reducing the melt viscosity and meeting the requirements of complex molding. Regarding dimensional stability, the shrinkage rate of the examples was ≤0.8%, superior to the >1.5% of the traditional process, while the shrinkage rate of Comparative Example 2, without the addition of a nucleating agent, reached 1.0%, confirming the crucial role of the nucleating agent (nano boron nitride) in optimizing the crystal structure and inhibiting shrinkage. In terms of mechanical properties, the tensile strength of the examples is ≥35MPa, exceeding the 30MPa of pure ultra-high molecular weight polyethylene. In particular, Example 4, reinforced with carbon nanotubes, has the highest strength of 38MPa, demonstrating the synergistic effect of the reinforcing material and the highly dispersed masterbatch. Regarding the functional modification effect, the examples with added thermally conductive materials such as silicon carbide or aluminum nitride have a thermal conductivity ≥0.9W / m·K, while the comparative example 3 without added thermally conductive materials has a thermal conductivity of only 0.5W / m·K and a decrease in strength, proving the necessity of thermally conductive materials for comprehensive performance.

Claims

1. A high dispersion masterbatch modified ultra-high molecular weight polyethylene, characterized in that, The raw materials include the following quality parts: carrier resin: 82-93 parts; Lubricant: 0.5-5 parts; antioxidant: 0.3-1 part; Nucleating agent: 1-2 parts; Thermal conductive material: 2-5 parts; reinforcing material: 3-5 parts; the thermal conductive material is silicon carbide or aluminum nitride powder; the reinforcing material is one of glass fiber powder or carbon nanotube.

2. The highly dispersed master pellet modified ultra-high molecular weight polyethylene according to claim 1, characterized in that, The carrier resin is medium-high molecular weight polyethylene with a molecular weight of 500-600 thousand; the lubricant is one or more of calcium stearate, oxidized polyethylene wax or coupling agent modified nano-SiO2; the antioxidant is a high molecular weight hindered phenolic antioxidant compounded with a phosphite antioxidant at a mass ratio of 1:2; the nucleating agent is nano-boron nitride with a particle size of 80-200 nm.

3. A method for preparing a high molecular weight polyethylene modified with the highly dispersed master batch according to claim 1 or 2, characterized in that, The method includes the following steps: (1) low temperature premixing: under nitrogen protection, the carrier resin, lubricant, antioxidant, nucleating agent, thermal conductive material and reinforcing material are added to the internal mixer, the initial temperature is 200-250℃, and the rotation speed is 30-60r / min; (2) high temperature and high speed dispersion: the temperature is raised to 280-300℃, and the rotation speed is raised to 200-300r / min; (3) extrusion granulation: the melt after mixing is transferred to a double screw extruder, and then melted, extruded, water cooled and granulated to obtain masterbatch; (4) the masterbatch is crushed by air flow mill or ball mill to obtain powder; (5) dry mixing and stirring according to the mass ratio of masterbatch powder: high molecular weight polyethylene=(1-3):(7-9), and then molding, extruding or injection molding to obtain high dispersion masterbatch modified ultra-high molecular weight polyethylene.

4. The method of claim 3, wherein the high dispersion masterbatch modified ultra-high molecular weight polyethylene is prepared by the steps of: (a) mixing the ultra-high molecular weight polyethylene, the dispersant, and the antioxidant to form a mixture; (b) melting the mixture; (c) extruding the mixture; and (d) cooling the extruded mixture. In step (1), the mixing time is 10-20 min; in step (2), the mixing time is 3-5 min.

5. The method of claim 3, wherein the high dispersion masterbatch modified ultra-high molecular weight polyethylene is prepared by the steps of: (a) mixing the ultra-high molecular weight polyethylene, the dispersant, and the antioxidant to form a mixture; (b) melting the mixture; (c) extruding the mixture; and (d) cooling the extruded mixture. In step (3), the length-diameter ratio of the double screw extruder is 40:1, and the temperature partition is 200-260℃.

6. The method for preparing highly dispersed masterbatch-modified ultra-high molecular weight polyethylene according to claim 3, characterized in that, In step (5), the dry mixing and stirring use a high-speed mixer with a rotation speed of 500-1000r / min, and the mixing time is 10-15 min.

7. The method for preparing highly dispersed masterbatch-modified ultra-high molecular weight polyethylene according to claim 3, characterized in that, In step (5), the molding pressure is 10-20 MPa, and the temperature is 220-240℃.

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