Ultrahigh molecular weight polyethylene composite material as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of polymer-based composite material forming, and provides an ultra-high molecular weight polyethylene composite material and a preparation method and application thereof, and the material is prepared from the following raw materials in parts by mass: 90-99 parts of ultra-high molecular weight polyethylene and 1-10 parts of one-dimensional nano filler. The preparation method comprises the following steps: (1) mixing a one-dimensional nanofiller with ultra-high molecular weight polyethylene, and performing pulse vibration compression molding to obtain a composite melt blank; (2) the composite melt blank is subjected to first-time equal-proportion cutting and then stacked for first-time pulse vibration compression molding, and a uniaxial orientation composite melt blank is obtained; the uniaxial orientation composite melt blank is subjected to secondary equal-proportion cutting in the direction perpendicular to the primary equal-proportion cutting direction, secondary pulse vibration compression molding is carried out after stacking, and a biaxial orientation composite melt blank is obtained; and (3) repeating the operation on the biaxial orientation composite melt blank according to the step (2), and cooling to obtain the ultra-high molecular weight polyethylene composite material.

Description

Technical Field

[0001] The invention relates to the technical field of polymer-based composite material molding, and in particular to an ultra-high molecular weight polyethylene composite material and a preparation method and application thereof. Background Art

[0002] Polymer bearing materials have gradually replaced some metals as new bearing materials due to their advantages such as light weight, corrosion resistance, self-lubrication, and low noise. However, during use, some inherent defects of the intrinsic structure of polymer materials, such as low strength, poor load-bearing capacity, and poor wear resistance, limit their application in the field of bearings. The existing technology usually uses filler blending, fiber cloth pre-impregnation, grafting modification and other reinforcement measures to enhance polymer bearing materials to varying degrees. However, the introduction of new reinforcement materials can easily cause processing difficulties, poor composite system interface, low filler utilization efficiency, and other problems, and the final product cannot achieve the desired effect. Summary of the invention

[0003] The purpose of the present invention is to overcome the defects in the prior art and provide an ultra-high molecular weight polyethylene composite material and a preparation method and application thereof.

[0004] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0005] The present invention provides an ultra-high molecular weight polyethylene composite material, which is prepared from raw materials containing the following parts by weight:

[0006] 90-99 parts of ultra-high molecular weight polyethylene and 1-10 parts of one-dimensional nano filler.

[0007] Preferably, the viscosity average molecular weight of the ultra-high molecular weight polyethylene is 1 million to 10 million;

[0008] The one-dimensional nanofiller is halloysite nanotube and / or zinc oxide nanowire.

[0009] The present invention also provides a method for preparing the ultra-high molecular weight polyethylene composite material, comprising the following steps:

[0010] (1) mixing a one-dimensional nanofiller with ultra-high molecular weight polyethylene and performing pulse vibration compression molding to obtain a composite melt blank;

[0011] (2) cutting the composite melt blank into equal proportions for the first time, stacking the blanks and performing the first pulse vibration compression molding to obtain a uniaxially oriented composite melt blank; cutting the uniaxially oriented composite melt blank into equal proportions for the second time in a direction perpendicular to the first equal proportion cutting direction, stacking the blanks and performing the second pulse vibration compression molding to obtain a biaxially oriented composite melt blank;

[0012] (3) Cool the biaxially oriented composite melt blank after repeating the operation in step (2), and the ultra-high molecular weight polyethylene composite material is obtained.

[0013] Preferably, the force field waveforms of the pulsed vibration molding in step (1), the first pulsed vibration molding in step (2), and the second pulsed vibration molding in step (2) are independently sine waves, square waves or triangular waves.

[0014] Preferably, the frequencies of the pulsed vibration molding in step (1), the first pulsed vibration molding in step (2), and the second pulsed vibration molding in step (2) are independently 0.1 - 10 Hz, and the peak pressures are independently 0 - 50 MPa.

[0015] Preferably, the temperatures of the pulsed vibration molding in step (1), the first pulsed vibration molding in step (2), and the second pulsed vibration molding in step (2) are independently 140 - 250 °C.

[0016] Preferably, the times of the pulsed vibration molding in step (1), the first pulsed vibration molding in step (2), and the second pulsed vibration molding in step (2) are independently 1 - 60 min.

[0017] Preferably, the number of repetitions in step (3) ≥ 1 time.

[0018] Preferably, the cooling rate in step (3) is 5 - 10 °C / min, and the pressure is 0.1 - 50 MPa.

[0019] The present invention also provides the application of the ultra-high molecular weight polyethylene composite material or the ultra-high molecular weight polyethylene composite material prepared by the preparation method of the ultra-high molecular weight polyethylene composite material in bearing products.

[0020] The present invention provides an ultra-high molecular weight polyethylene composite material, which is prepared from raw materials comprising the following mass parts: 90 - 99 parts of ultra-high molecular weight polyethylene and 1 - 10 parts of one-dimensional nano-fillers. The present invention also provides a preparation method of the ultra-high molecular weight polyethylene composite material. (1) Mix the one-dimensional nano-fillers with ultra-high molecular weight polyethylene and then perform pulsed vibration molding to obtain a composite melt blank; (2) First, cut the composite melt blank proportionally and then stack and perform the first pulsed vibration molding to obtain a uniaxially oriented composite melt blank; Cut the uniaxially oriented composite melt blank in the direction perpendicular to the first proportional cutting direction, stack and perform the second pulsed vibration molding to obtain a biaxially oriented composite melt blank; (3) Cool the biaxially oriented composite melt blank after repeating the operation in step (2), and the ultra-high molecular weight polyethylene composite material is obtained.

[0021] Under the action of a pulsating force field, the ultra-high molecular weight polyethylene composite melt blank is cut and laminated in different directions. Through repeated cutting, lamination, and pulsed vibration molding, the orientation degree of the filler and the matrix in the composite material can be significantly improved, achieving the effect of synergistic orientation of the filler-matrix. Due to the action of the pulsed vibration force field, the molecular chains of ultra-high molecular weight polyethylene can be "forced" to move, and the filler can form a more "solid" interface with ultra-high molecular weight polyethylene, maintaining good interfacial strength during the orientation process, thereby better exerting its reinforcing effect and further improving the mechanical properties and wear resistance of the composite material. Detailed implementation mode

[0022] The present invention provides an ultra-high molecular weight polyethylene composite material, which is prepared from raw materials containing the following mass parts:

[0023] 90 - 99 parts of ultra-high molecular weight polyethylene and 1 - 10 parts of one-dimensional nano-filler.

[0024] In the present invention, the mass parts of the ultra-high molecular weight polyethylene are preferably 91 - 98 parts, further preferably 93 - 98 parts, and more preferably 95 - 98 parts.

[0025] In the present invention, the mass parts of the one-dimensional nano-filler are preferably 2 - 9 parts, further preferably 2 - 7 parts, and more preferably 2 - 5 parts.

[0026] In the present invention, the viscosity-average molecular weight of the ultra-high molecular weight polyethylene is preferably 1 million - 10 million, further preferably 2 million - 9 million, and more preferably 3 million - 8 million.

[0027] In the present invention, the one-dimensional nano-filler is halloysite nanotubes and / or zinc oxide nanowires; the use of the one-dimensional nano-filler can effectively improve the mechanical properties and wear resistance of the composite material.

[0028] The present invention also provides a preparation method of the ultra-high molecular weight polyethylene composite material, which comprises the following steps:

[0029] (1) Mix the one-dimensional nano-filler with ultra-high molecular weight polyethylene and then perform pulsed vibration molding to obtain a composite melt blank;

[0030] (2) Cut the composite melt blank in equal proportion for the first time and then laminate and perform pulsed vibration molding for the first time to obtain a uniaxially oriented composite melt blank; cut the uniaxially oriented composite melt blank in the direction perpendicular to the first equal-proportion cutting direction, laminate, and then perform pulsed vibration molding for the second time to obtain a biaxially oriented composite melt blank;

[0031] (3) Repeating the operation of step (2) on the biaxially oriented composite melt billet and then cooling it to obtain the ultra-high molecular weight polyethylene composite material.

[0032] The present invention does not specifically limit the mixing method in step (1), and a person skilled in the art can obtain well-dispersed powder by a well-known method. Meanwhile, the present invention provides a solution method for mixing, which is as follows:

[0033] Disperse the one-dimensional nanofiller in ethanol, and ultrasonicate for 30 to 60 minutes, preferably 40 to 50 minutes, and more preferably 44 to 46 minutes; obtain an ethanol dispersion of nanoparticles; disperse the ultra-high molecular weight polyethylene powder in the ethanol solution, heat and stir at 60 to 80°C, preferably at 65 to 75°C, and more preferably at 68 to 72°C to obtain an ultra-high molecular weight polyethylene suspension; then mix the two dispersions, the mixing speed is preferably 300 to 500 rpm, more preferably 350 to 450 rpm, and more preferably 380 to 420 rpm; the mixing temperature is preferably 60 to 80°C, more preferably 65 to 75°C, and more preferably 68 to 72°C; stir thoroughly until the ethanol is completely evaporated. Dry the composite powder after the ethanol is volatilized to obtain a composite powder; the drying temperature is preferably 70 to 100°C, more preferably 75 to 95°C, and more preferably 80 to 90°C; the time is preferably 4 to 8 hours, more preferably 4.5 to 7.5 hours, and more preferably 5 to 7 hours.

[0034] In the present invention, the force field waveforms of the pulse vibration molding in step (1), the first pulse vibration molding in step (2), and the second pulse vibration molding in step (2) are independently sine waves, square waves, or triangular waves.

[0035] The present invention has no special limitation on the equipment for pulse vibration compression molding, and equipment well known to those skilled in the art can be used. The equipment for pulse vibration compression molding used in the present invention refers to patent CN113021725A.

[0036] In the present invention, the frequencies of the pulse vibration compression molding in step (1), the first pulse vibration compression molding in step (2), and the secondary pulse vibration compression molding in step (2) are independently preferably 0.1 to 10 Hz, further independently preferably 1 to 9 Hz, and more independently preferably 2 to 5 Hz; the peak pressure is independently preferably 0 to 50 MPa, further independently preferably 10 to 40 MPa, and more independently preferably 15 to 30 MPa.

[0037] In the present invention, the temperature for the pulse vibration molding in step (1), the first pulse vibration molding in step (2), and the second pulse vibration molding in step (2) is preferably independently 140 - 250 °C, more preferably independently 150 - 240 °C, and even more preferably independently 155 - 210 °C.

[0038] In the present invention, the time for the pulse vibration molding in step (1), the first pulse vibration molding in step (2), and the second pulse vibration molding in step (2) is preferably independently 1 - 60 min, more preferably independently 2 - 50 min, and even more preferably independently 2 - 10 min.

[0039] In the present invention, after the pulse vibration molding in step (1), a composite melt blank with uniform melting and good interfacial properties can be obtained; in step (2), when cutting and laminating, the composite melt blank will be stretched and oriented along the cutting direction, and during this process, the one-dimensional nano-fillers will also be oriented and arranged. Under the action of the pulsed vibration force field, due to the action of the periodic force field, the orientation of the composite material can be further promoted. During the lamination and orientation process, the pulsed vibration force field can also enhance the interfacial properties between the filler and the matrix, achieving the effect of physical compatibilization, and finally obtaining a composite material with good interfacial properties.

[0040] The present invention has no special limitation on the operation of the equal-proportion cutting, and it can be operated according to the routine.

[0041] The present invention has no special limitation on the operation of the lamination, as long as it is ensured that the composite melt blanks after equal-proportion cutting are completely overlapped up and down.

[0042] In the present invention, the number of repetitions in step (3) is preferably ≥ 1 time, more preferably ≥ 5 times, and even more preferably ≥ 8 times; through the repeated operation, a biaxially oriented composite melt blank layer is obtained, and the more the number of repetitions, the more excellent the performance of the obtained composite melt blank layer.

[0043] The present invention can effectively regulate the orientation degree of the matrix and the filler by controlling the number of repetitions, thereby regulating its mechanical properties and wear resistance; the present invention conducts multiple cutting and lamination on the ultra-high molecular weight polyethylene composite melt blank, and uses the pulsed vibration force field to repeatedly perform molding and orientation on the cut and laminated composite melt blank, achieving the effect of synergistic orientation of the filler - matrix, and can prepare a biaxially oriented ultra-high molecular weight polyethylene composite material bearing blank with good interfacial properties; at the same time, the orientation degree can be improved without reducing the thickness of the composite material.

[0044] In the present invention, the cooling rate in step (3) is preferably 5-10 °C / min, more preferably 6-9 °C / min, and still more preferably 7-8 °C / min; the pressure is preferably 0.1-50 MPa, more preferably 10-40 MPa, and still more preferably 15-30 MPa.

[0045] The present invention also provides an application of the ultra-high molecular weight polyethylene composite material or the ultra-high molecular weight polyethylene composite material prepared by the preparation method of the ultra-high molecular weight polyethylene composite material in bearing products.

[0046] The technical solutions provided by the present invention will be described in detail below with reference to the embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0047] Example 1

[0048] (a) Take 98 parts of ultra-high molecular weight polyethylene (viscosity-average molecular weight of 5 million) and 2 parts of halloysite nanotubes. Disperse the halloysite nanotubes in ethanol and ultrasonicate for 30 min to obtain an ethanol dispersion of nanoparticles; disperse the ultra-high molecular weight polyethylene powder in an ethanol solution, heat and stir at 70 °C to obtain an ultra-high molecular weight polyethylene suspension; then mix the two dispersions under the conditions of stirring at 400 r / min and heating at 70 °C, and stir thoroughly until the ethanol completely evaporates. Place the composite powder after ethanol volatilization in an oven at 80 °C and dry for 6 h to obtain a composite powder.

[0049] (b) Pour the composite powder into a square non-bleeding mold, control the temperature at 210 °C, the time at 5 min, the force field waveform as a sine wave, the frequency at 5 Hz, and the peak pressure at 20 MPa to obtain a composite melt blank.

[0050] (c) Cut the composite melt blank in equal proportions and stack them, place them in the central position of a square non-bleeding mold, and then perform pulsed vibration molding (temperature at 155 °C, time at 2 min, force field waveform as a sine wave, frequency at 2 Hz, peak pressure at 20 MPa) to obtain a uniaxially oriented composite melt blank; then cut the obtained uniaxially oriented composite melt blank in equal proportions along the direction perpendicular to the cutting direction and stack them, place them in the central position of a square non-bleeding mold, and then perform secondary pulsed vibration molding (temperature at 155 °C, time at 2 min, force field waveform as a sine wave, frequency at 2 Hz, peak pressure at 20 MPa) to obtain a biaxially oriented composite melt blank, and the size of the biaxially oriented composite melt blank is the same as that of the composite melt blank.

[0051] (d) Repeat the operation in step (c) for the biaxially oriented composite melt blank twice to obtain a biaxially oriented composite melt blank layer; then cool and shape the biaxially oriented composite melt blank layer at a rate of 8.5 °C / min under a pressure of 20 MPa to obtain an ultra-high molecular weight polyethylene composite material.

[0052] Example 2

[0053] On the basis of Example 1, the pulse vibration molding conditions in steps (b), (c), and (d) are not set with a sine wave force field waveform, but are set to be carried out in a static force field; the pressure of the static force field is 20 MPa, and other conditions remain unchanged, to obtain a biaxially oriented ultra-high molecular weight polyethylene composite bearing product.

[0054] Example 3

[0055] The difference between Example 3 and Example 1 is that instead of using one-dimensional nano-fillers, all raw materials are ultra-high molecular weight polyethylene, and other conditions remain unchanged.

[0056] Example 4

[0057] The difference between Example 4 and Example 1 is that changing the operation in step (d) from being repeated twice to being repeated once, and other conditions remain unchanged.

[0058] Comparative Example 1

[0059] A preparation method for an ultra-high molecular weight polyethylene material bearing product without filler reinforcement and cutting layer lamination hot pressing orientation consists of the following steps:

[0060] (1) Pour ultra-high molecular weight polyethylene powder with a viscosity-average molecular weight of 5 million into a square non-overflow mold, and perform static molding to obtain a composite melt blank; among them, the molding temperature is 210 °C and the time is 35 min;

[0061] (2) Cool and shape the melt blank obtained in step (1) at a rate of 8.5 °C / min under a pressure of 20 MPa to obtain an unfilled-reinforced and laminated-oriented ultra-high molecular weight polyethylene bearing blank.

[0062] Perform performance tests on Examples 1 to 4 and Comparative Example 1. The tensile performance is tested according to the standard GB / T 1040.2-2022, the compression performance is tested according to GB / T 1041-2008, the sliding friction and wear performance is tested according to GB / T 3960-2016, and the mortar abrasion performance is tested according to SH / T 1818-2017. The results are recorded in Table 1.

[0063] Table 1 Test Results

[0064] Tensile strength (MPa) Compressive strength (MPa) Coefficient of friction Wear rate (%) Example 1 186.3 151.2 0.15 1.15 Example 2 135.5 139.4 0.21 1.39 Example 3 175.7 131.3 0.17 1.41 Example 4 110.5 134.4 0.24 1.37 Comparative example 1 36.5 63.2 0.35 2.06

[0065] As can be seen from the above embodiments, the ultra-high molecular weight polyethylene composite material provided by the present invention has the characteristics of high strength, low friction coefficient and excellent wear resistance, and has great development prospects in the bearing field.

[0066] The above are only the preferred embodiments of the present invention. It should be noted 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. An ultra-high molecular weight polyethylene composite material, characterized in that: Prepared from the following raw materials in parts by weight: 90-99 parts of ultra-high molecular weight polyethylene and 1-10 parts of one-dimensional nano filler.

2. The ultra-high molecular weight polyethylene composite material according to claim 1, characterized in that: The viscosity average molecular weight of the ultra-high molecular weight polyethylene is 1 million to 10 million; The one-dimensional nanofiller is halloysite nanotube and / or zinc oxide nanowire.

3. The method for preparing the ultra-high molecular weight polyethylene composite material according to claim 1 or 2, characterized in that: It includes the following steps: (1) mixing a one-dimensional nanofiller with ultra-high molecular weight polyethylene and performing pulse vibration compression molding to obtain a composite melt blank; (2) cutting the composite melt blank into equal proportions for the first time, stacking the blanks and performing the first pulse vibration compression molding to obtain a uniaxially oriented composite melt blank; cutting the uniaxially oriented composite melt blank into equal proportions for the second time in a direction perpendicular to the first equal proportion cutting direction, stacking the blanks and performing the second pulse vibration compression molding to obtain a biaxially oriented composite melt blank; (3) Repeating the operation of step (2) on the biaxially oriented composite melt billet and then cooling it to obtain the ultra-high molecular weight polyethylene composite material.

4. The method for preparing the ultra-high molecular weight polyethylene composite material according to claim 3, characterized in that: The force field waveforms of the pulse vibration molding in step (1), the first pulse vibration molding in step (2), and the second pulse vibration molding in step (2) are independently sine waves, square waves, or triangular waves.

5. The method for preparing the ultra-high molecular weight polyethylene composite material according to claim 4, characterized in that: The frequencies of the pulse vibration compression molding in step (1), the first pulse vibration compression molding in step (2), and the secondary pulse vibration compression molding in step (2) are independently 0.1 to 10 Hz, and the peak pressures are independently 0 to 50 MPa.

6. The method for preparing the ultra-high molecular weight polyethylene composite material according to claim 5, characterized in that: The temperatures of the pulse vibration compression molding in step (1), the first pulse vibration compression molding in step (2), and the second pulse vibration compression molding in step (2) are independently 140 to 250°C.

7. The method for preparing the ultra-high molecular weight polyethylene composite material according to claim 6, characterized in that: The time for the pulse vibration compression molding in step (1), the first pulse vibration compression molding in step (2), and the second pulse vibration compression molding in step (2) are independently 1 to 60 minutes.

8. The method for preparing the ultra-high molecular weight polyethylene composite material according to claim 7, characterized in that: The number of repetitions in step (3) is ≥ 1.

9. The method for preparing the ultra-high molecular weight polyethylene composite material according to claim 8, characterized in that: The cooling rate in step (3) is 5-10°C / min and the pressure is 0.1-50MPa.

10. Use of the ultra-high molecular weight polyethylene composite material according to claim 1 or 2 or the ultra-high molecular weight polyethylene composite material prepared by the preparation method of the ultra-high molecular weight polyethylene composite material according to any one of claims 3 to 9 in bearing products.