Ultra-high molecular weight polyethylene heavy-load lubricating material and preparation method thereof

Abstract

The present invention provides an ultra-high molecular weight polyethylene heavy-duty lubricating material and a preparation method thereof. The ultra-high molecular weight polyethylene is used as a polymer matrix, polyaryletherketone is used as a main reinforcing filler, and a small amount of reinforcing is used as a modified component. The material is prepared through mechanical blending, sintering molding, pressing and shaping, and trimming processing. The present invention utilizes the rigid skeleton structure of polyaryletherketone itself to improve the bearing capacity of the ultra-high molecular weight polyethylene matrix while maintaining its elongation and toughness unaffected; combines a small amount of inorganic reinforcing filler to further improve its bearing capacity; combines a secondary pressing and shaping process to further improve the density of the molded material, improve the bearing capacity of the composite material, meet the service requirements of high-load friction conditions, and is mainly used to manufacture lubricating materials for service under heavy-load conditions such as ship decks and bridge bearings. It belongs to the field of supporting structure materials or lubricating materials.

Description

Technical Field

[0001] The present invention relates to an ultra-high molecular weight polyethylene lubricating material, and in particular to a modified ultra-high molecular weight polyethylene lubricating material used under heavy-load conditions. The present invention is mainly used for manufacturing lubricating materials serving under heavy-load conditions such as ship decks and bridge supports, and belongs to the field of supporting structure materials or lubricating materials. Background Art

[0002] Ultra-high molecular weight polyethylene has excellent friction and wear properties, but its mechanical properties are insufficient, which is most evident in its low load-bearing capacity and susceptibility to creep. Especially under heavy-load conditions, ultra-high molecular weight polyethylene often suffers from rapid wear and failure due to excessively high specific pressure, which causes the friction coefficient and wear rate to increase sharply and become unstable. Conventional modification methods improve the load-bearing capacity of composite materials to a certain extent by introducing various inorganic fillers with high load-bearing capacity into ultra-high molecular weight polyethylene. However, the introduction of high levels of inorganic fillers inevitably blocks the continuity and extensibility of the ultra-high molecular weight linear polymer chains, resulting in a significant decrease in the elongation and toughness, and even tensile strength, of the composite material.

[0003] Polyaryletherketone (PAEK) is a semicrystalline thermoplastic engineering plastic composed of phenylene groups linked alternately by ether and ketone groups. Because its molecular structure contains rigid benzene rings, PAEK exhibits significantly superior mechanical properties and load-bearing capacity compared to ultra-high molecular weight polyethylene (UHMWPE). This makes it suitable for manufacturing heavy-duty components such as gear housings, bearings, bushings, and gears in aerospace, marine engineering, and other fields. However, PAEK itself is expensive, making it uneconomical when used alone, and its manufacturing process is complex. Summary of the Invention

[0004] The purpose of the present invention is to provide an ultra-high molecular weight polyethylene heavy-load lubricating material and a preparation method thereof to address the bottleneck problems of insufficient load-bearing capacity and unsatisfactory friction and wear performance of existing ultra-high molecular weight polyethylene lubricating materials under heavy-load conditions.

[0005] 1. Preparation of ultra-high molecular weight polyethylene heavy-load lubricating materials

[0006] The present invention uses ultra-high molecular weight polyethylene as the polymer matrix, polyaryletherketone as the main reinforcing filler, and a small amount of reinforcing as a modified component. It is produced through mechanical blending, sintering, pressing and shaping, and edge trimming. The specific raw material ratio and preparation process are as follows:

[0007] Raw material components: by weight, 60-85 parts of ultra-high molecular weight polyethylene, 5-35 parts of polyaryletherketone, and 0.1-3 parts of reinforcing filler.

[0008] Among the raw material components, the particle size of ultra-high molecular weight polyethylene is 10~60μm, and the molecular weight is (1.5~7.0)×10 6g / mol. The polyaryletherketone is one or more of polyetherketone, polyetheretherketoneketone, and polyetherketoneketone, and has a particle size of 10 to 80 μm. The reinforcing filler is one or more of carbon fiber, glass fiber, calcium carbonate, silica, and solid glass beads, and has a size of 30 to 200 μm.

[0009] In terms of the raw material component design of the composite material of the present invention, the polyaryletherketone has a high load-bearing capacity and excellent friction and wear properties under heavy-load and high-pressure conditions. After being compounded with an ultra-high molecular weight polyethylene matrix, the load-bearing capacity and lubricating filler of the composite material can be effectively improved; combined with a small amount of reinforcing filler, the load-bearing capacity of the composite material can be further improved, and the decline in elongation and impact toughness caused by the high content of inorganic fillers can be controlled, thereby comprehensively improving the mechanical strength and flexibility of the ultra-high molecular weight polyethylene composite material, especially the friction and wear performance under heavy-load conditions.

[0010] Preparation process: including the following steps:

[0011] (1) Mechanical blending: Ultra-high molecular weight polyethylene, polyaryletherketone and reinforcing filler are placed in a mechanical mixer and mixed evenly to obtain a mixed material. Mechanical blending is carried out in a twin-shaft mixer. The shearing tool speed in the mixing kettle is 50-1000 pm, the overall speed of the mixing kettle around the cantilever is 5-20 rpm, and the mixing time is 3-40 min.

[0012] (2) Sintering: Place the mixed powder in a precision molding machine mold and sinter at 2-15 MPa and 195-225°C for 30-210 min to obtain a sintered blank. The obtained sintered blank is in the shape of a plate with a length of 80-1500 mm, a width of 50-200 mm, and a thickness of 1-10 mm.

[0013] (3) Pressing and shaping: The sintered blank is shaped in an open embedded mold at a temperature of 30-60°C and a pressure of 10-60 MPa for 30-120 min to obtain a press-shaped blank. Pressing and shaping is carried out in a plate mold with a pressing rate of 0.5-10 mm / min and an embedding depth of 50%-80% of the sintered blank.

[0014] (4) Edge trimming: The deformed edges in the length and width directions of the pressed and shaped blank are mechanically removed in a double-axis edge trimming machine to obtain ultra-high molecular weight polyethylene heavy-duty lubricating material. The trimming size is 1% to 15% of the length and width dimensions, and the cutting speed is 5 to 100 mm / s.

[0015] In terms of preparation technology, the present invention realizes uniform blending of multiple components by controlling the parameters of mechanical blending process, and ensures the performance and dimensional precision of the composite material by regulating the process flow and parameters of sintering molding, pressing shaping and edge trimming. In particular, the pressing shaping process is used to improve the density of the molding material, thereby solving the problems of high friction coefficient and wear rate of the composite material caused by insufficient load-bearing capacity of ultra-high molecular weight polyethylene itself.

[0016] 2. Performance test of ultra-high molecular weight polyethylene heavy-load lubricating material

[0017] 1. Friction and wear performance test

[0018] Test method: According to ASTM G99-05, the prepared polytetrafluoroethylene lubricant material molded product was processed into a block specimen with dimensions of 19mm × 12mm × 12mm. The specimen was paired with a high-carbon chromium bearing steel ring (GCr15) and tested in an MRH-3 high-speed ring-block friction and wear tester. The test contact load was 800N-1200N, the linear speed was 0.5m / s, and the running time was 30min. The friction coefficient was automatically recorded and output by the tester, and the wear rate was calculated from the mass loss of the sample before and after wear.

[0019] Test results: The friction coefficient of the ultra-high molecular weight polyethylene lubricating material prepared by the present invention is 0.02~0.05, and the wear rate is (1.2~5.7) ×10 -5 mm 3 / Nm. It can be seen that the ultra-high molecular weight polyethylene lubricating material has excellent friction coefficient and wear rate under heavy load conditions above 800N.

[0020] 2. Tensile strength test

[0021] Test method: Ultra-high molecular weight polyethylene heavy-duty lubricating material was prepared and machined into the dimensions specified by the national standard. Mechanical properties were tested on a universal testing machine. The tensile strength specimen was a dumbbell-shaped 80 mm × 10 mm × 4 mm. The test standard was GB / T 1040.2-2006, and the tensile rate was 10 mm / min.

[0022] Test results show that the ultra-high molecular weight polyethylene heavy-duty lubricant prepared in this invention has a tensile strength of 20-33 MPa and an elongation of 150%-280%. This indicates that the ultra-high molecular weight polyethylene heavy-duty lubricant has excellent tensile strength, and in particular, a tensile elongation that far exceeds the safe use limit of 50%.

[0023] 3. Notched impact strength test

[0024] Test Method: The prepared ultra-high molecular weight polyethylene heavy-duty lubricant was machined into the dimensions specified in the national standard and subjected to mechanical property testing on a universal testing machine. The specimens were 80 mm × 10 mm × 4 mm strips with a double-sided B-notch as specified in ISO 2818:1994. The test standard was GB / T 1043.1-2008, and the pendulum kinetic energy was 7.5 J.

[0025] Test results: The notched impact strength of the ultra-high molecular weight polyethylene heavy-duty lubricating material prepared by the present invention is 150~250kJ / m 2 It can be seen that the ultra-high molecular weight polyethylene heavy-load lubricating material has excellent impact strength.

[0026] In summary, the present invention uses ultra-high molecular weight polyethylene resin as the polymer matrix and polyaryletherketone as the main modified filler. It utilizes the rigid skeleton structure of polyaryletherketone itself to improve the load-bearing capacity of the ultra-high molecular weight polyethylene matrix while maintaining its elongation and toughness unaffected; combines with a small amount of inorganic reinforcing filler to further improve its load-bearing capacity; combines with the secondary pressing and shaping process to further improve the density of the molding material, improve the load-bearing capacity of the composite material, and meet the service requirements of high-load friction conditions. DETAILED DESCRIPTION

[0027] The preparation method and properties of the ultra-high molecular weight polyethylene heavy-load lubricating material of the present invention are further described below through specific examples.

[0028] Example 1

[0029] (1) Mechanical blending: Take 850g of ultra-high molecular weight polyethylene resin (particle size 30μm, molecular weight 3.0×10 6 g / mol), 140g of polyether ketone (60μm particle size), and 10g of glass fiber (100μm size) were placed in a biaxial mixer and mixed for 10 minutes. The shear blades in the mixer rotated at 400rpm, and the entire mixer rotated around the cantilever at 10rpm.

[0030] (2) Sintering: 515 g of the mixture was placed in a precision molding machine mold and sintered at a pressure of 10 MPa and a temperature of 210°C for 60 min. The sintered blank had a plate shape with a length of 1000 mm, a width of 50 mm, and a thickness of 12 mm.

[0031] (3) Pressing and shaping: Place the sintered blank into the embedded mold, adjust the length and width of the movable mold to clamp the blank, and embed the blank to a depth of 6 mm (50% embedding depth). Apply pressure to 45 MPa at a rate of 1 mm / min, and then shape at 60°C for 60 minutes to obtain a press-shaped blank.

[0032] (4) Edge trimming: A pressed, shaped blank with dimensions of 1080 mm in length, 54 mm in width, and 10 mm in thickness was placed in a dual-axis edge trimming machine. 100 mm (9.2%) of the length and 5 mm (9.2%) of the width were trimmed at a cutting speed of 10 mm / s to obtain an ultra-high molecular weight polyethylene heavy-duty lubricant. The properties of the resulting lubricant are shown in Table 1.

[0033] Example 2

[0034] (1) Mechanical blending: Take 620g of ultra-high molecular weight polyethylene resin (particle size 45μm, molecular weight 6.0×10 6 g / mol), 350g of polyetherketone ketone (80μm particle size), and 30g of calcium carbonate (60μm particle size) were placed in a biaxial mixer and mixed for 30 minutes. The shear blades in the mixer rotated at 800 rpm, and the entire mixer rotated around the cantilever at 20 rpm.

[0035] (2) Sintering: 700g of the mixed material was placed in a precision molding machine mold and sintered at a pressure of 2MPa and a temperature of 200℃ for 180min. The sintered blank was in the shape of a plate with a length of 1200mm, a width of 200mm, and a thickness of 2.5mm.

[0036] (3) Pressing and shaping: Place the sintered blank into the embedded mold, adjust the length and width of the movable mold to clamp the blank, and embed the blank to a depth of 2 mm (80% embedding depth). Apply pressure to 60 MPa at a speed of 5 mm / min, and then shape at 30°C for 100 minutes to obtain the pressed and shaped blank;

[0037] (4) Edge trimming: A pressed, shaped blank with dimensions of 1211 mm in length, 207 mm in width, and 2 mm in thickness was placed in a biaxial edge trimming machine. 50 mm (4.1%) of the edge was trimmed in the longitudinal direction and 10 mm (4.8%) of the edge was trimmed in the width direction at a cutting speed of 5 mm / s to obtain an ultra-high molecular weight polyethylene heavy-duty lubricant. The properties of the resulting lubricant are shown in Table 1.

[0038] Example 3

[0039] (1) Mechanical blending: Take 55g of ultra-high molecular weight polyethylene resin (particle size 10μm, molecular weight 2.1×10 6 g / mol), 200g of polyetheretherketone ketone (10μm particle size), and 5g of solid glass microspheres (120μm size) were placed in a biaxial mixer and mixed for 15 minutes. The shear blades in the mixer rotated at 50 rpm, and the entire mixer rotated around the cantilever at 5 rpm.

[0040] (2) Sintering: 700g of the mixture was placed in a precision molding machine mold and sintered for 180min at a pressure of 2MPa and a temperature of 200℃. The sintered blank was in the shape of a plate with a length of 100mm, a width of 100mm and a thickness of 5mm.

[0041] (3) Pressing and shaping: Place the sintered blank into the embedded mold, adjust the length and width of the movable mold to clamp the blank, and embed the blank to a depth of 3 mm (embedding depth 60%). Load the pressure to 20 MPa at a speed of 10 mm / min, and then shape it at 45 °C for 30 min to obtain the pressed and shaped blank.

[0042] (4) Edge trimming: A pressed blank with dimensions of 103 mm in length, 103 mm in width, and 4 mm in thickness was placed in a biaxial edge trimming machine. 3 mm (2.9%) was trimmed in the longitudinal direction and 3 mm (2.9%) in the width direction at a cutting speed of 10 mm / s to obtain an ultra-high molecular weight polyethylene heavy-duty lubricant. The properties of the obtained lubricant are shown in Table 1.

[0043]

[0044] Comparative Example 1

[0045] Raw material components: 990g ultra-high molecular weight polyethylene resin (particle size 30μm, molecular weight 3.0×10 6 g / mol), 10 g glass fiber (size 100 μm).

[0046] Preparation process: Same as Example 1. The properties of the obtained ultra-high molecular weight polyethylene composite material are shown in Table 2.

[0047] Comparative Example 2

[0048] Raw material components: 600g ultra-high molecular weight polyethylene resin (particle size 45μm, molecular weight 6.0×10 6 g / mol), 350g polyetherketone ketone (particle size 80μm), and 50g calcium carbonate (size 60μm).

[0049] Preparation process: Same as Example 2. The properties of the obtained ultra-high molecular weight polyethylene composite material are shown in Table 2.

[0050] Comparative Example 3

[0051] Raw material components: same as Example 3;

[0052] Preparation process: No pressing and shaping process was performed, and other processes were the same as those in Example 3. The properties of the obtained ultra-high molecular weight polyethylene composite material are shown in Table 2.

[0053]

[0054] By comparing the examples with the comparative examples, the following conclusions were drawn: (1) When no polyaryletherketone was added to the ultra-high molecular weight polyethylene resin matrix, the wear rate increased to 7.5×10 -5 mm 3 / N·m; (2) When the reinforcing filler content exceeds the agreed range, the strength and toughness of the composite material decrease significantly, as shown by: the tensile strength decreases to 18MPa, the elongation decreases to 35%, and the notched impact strength decreases to 75kg / m 2 ; (3) Without the pressing and shaping treatment, the friction coefficient of the composite material increased to 0.09 and the wear rate increased to 12.3×10 -5 mm / Nm, cannot simultaneously reach the performance range of the material described in the present invention.

[0055] The materials and reagents used in the above examples and comparative examples are all commercially available.

Claims

1. An ultra-high molecular weight polyethylene heavy-duty lubricating material is prepared using the following raw materials and processes: Raw material components: by weight, 60-85 parts of ultra-high molecular weight polyethylene, 5-35 parts of polyaryletherketone, and 0.1-3 parts of reinforcing filler; in the raw material components, the ultra-high molecular weight polyethylene has a particle size of 10-60 μm and a molecular weight of (1.5-7.0)×10 6 g / mol; the polyaryletherketone is one or more of polyetherketone, polyetheretherketoneketone, and polyetherketoneketone, and the particle size is 10-80 μm; the reinforcing filler is one or more of carbon fiber, glass fiber, calcium carbonate, silicon oxide, and solid glass beads, and the size of the reinforcing filler is 30-200 μm; Preparation process: including the following steps: (1) Mechanical blending: ultra-high molecular weight polyethylene, polyaryletherketone and reinforcing filler are placed in a mechanical mixer and mixed evenly to obtain a mixed material; (2) Sintering: Place the mixed powder in a precision molding machine mold and sinter at 2-15 MPa and 195-225°C for 30-210 min to obtain a sintered blank; (3) Pressing and shaping: In an embedded mold, the sintered blank is shaped at a temperature of 30-60°C and a pressure of 10-45 MPa for 30-120 min to obtain a press-shaped blank; (4) Edge trimming: The deformed edges in the length and width directions of the pressed shaped blank are removed by mechanical processing in a double-axis edge trimming machine to obtain ultra-high molecular weight polyethylene heavy-duty lubricating material.

2. The ultra-high molecular weight polyethylene heavy-load lubricating material according to claim 1, characterized in that: The mechanical blending of the preparation process is carried out in a double-shaft mixer, the shearing tool speed in the mixing kettle is 50-1000 rpm, the mixing kettle as a whole revolves around the cantilever at a speed of 5-20 rpm, and the mixing time is 3-40 min.

3. The ultra-high molecular weight polyethylene heavy-load lubricating material according to claim 1, characterized in that: In the sintering molding of the preparation process, the obtained sintered blank is in a plate shape with a length of 80 to 1500 mm, a width of 50 to 200 mm, and a thickness of 1 to 10 mm.

4. The ultra-high molecular weight polyethylene heavy-load lubricating material and its preparation method according to claim 1, characterized in that: The pressing and shaping of the preparation process is carried out in an embedded plate mold, the pressing rate is 0.5~10mm / min, and the embedding depth is 50%~80% of the sintered blank.

5. The ultra-high molecular weight polyethylene heavy-load lubricating material according to claim 1, characterized in that: In the edge trimming process of the preparation process, the trimming size is 1%~15% of the length and width, and the cutting speed is 5~100mm / s.

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