Oil-containing polymer composite material with high oil yield as well as preparation method and mold pressing method of oil-containing polymer composite material

Abstract

The invention provides an oil-containing polymer composite material as well as a preparation method and a mold pressing method thereof, and belongs to the technical field of polymer materials. The composite material is composed of a polymer matrix material, a lubricant, a filler and an auxiliary agent, the excellent self-lubricating performance is achieved by optimizing the proportion of all the components and a compounding process, the preparation method of the composite material adopts the processes of mixed melting, mold pressing, vulcanization, extrusion molding or injection molding and the like, the processes are simple, and industrial production is easy. The material is widely used for manufacturing various mechanical parts, such as bearings, gears, sliding blocks, guide rails and the like, and particularly has excellent performance in high-load, low-friction and less-maintenance industrial environments.

Description

Technical Field

[0001] The present invention relates to an oil-containing polymer composite material with a high oil yield, a preparation method thereof, and a molding method, belonging to the technical field of polymer materials, and is particularly suitable for fields such as mechanical lubrication and manufacturing of wear-resistant components. Background Art

[0002] In modern industry, the lubrication and wear resistance of mechanical components are one of the key factors affecting the operation efficiency and service life of equipment. Traditional lubrication methods usually rely on the regular addition of external lubricating oil or grease. This method not only increases the maintenance cost but also may cause equipment failures due to insufficient lubrication. Therefore, it is of great practical significance to develop a material with self-lubricating performance of high oil content and strong load-bearing capacity, which can effectively reduce the maintenance cost and improve the reliability and service life of equipment.

[0003] Polymer materials have been widely used in the manufacture of mechanical components due to their excellent wear resistance, corrosion resistance, and processability. However, most of the current oil-containing polymer materials have problems such as insufficient lubrication, insufficient material strength, or poor processability, which limit their wide application. The lubrication performance of ordinary polymer materials is limited and it is difficult to meet the use requirements in high-load and low-friction environments. For example, in Chinese Patent CN102558753B, an enhanced and toughened self-lubricating polyoxymethylene composite material and a preparation method thereof, the prepared composite material is uniformly dispersed, has good mechanical properties, and has good wear resistance, and can be used to prepare gears, instrument casings, etc. However, the oil content is relatively low (less than 5%), and the lubrication performance is limited, making it difficult to meet the use requirements in high-load and low-friction environments. Therefore, it is urgent to invent an oil-containing polymer composite material with a high oil yield to meet the use requirements of mechanical components in high-load and low-friction environments. Summary of the Invention

[0004] Aiming at the deficiencies of the existing technology, the present invention aims to provide an oil-containing polymer composite material with a high oil content, a preparation method thereof, and an application. This material has excellent self-lubricating performance, mechanical strength, and processability, and can meet the needs of various industrial application scenarios.

[0005] To achieve the above object, the present invention provides the following technical solutions: The oil-containing polymer composite material of the present invention is composed of the following components by weight percentage: An oil-containing polymer composite material with a high oil yield is composed of the following components by weight percentage: Polymer matrix material: 10% - 90%, the polymer matrix material is selected from one or more of ultra-high molecular weight polyethylene (UPE), polytetrafluoroethylene (PTFE), polyether ether ketone (PEEK), polyamide (PA6, PA66, PA46), polyamide-imide (PAI), polyoxymethylene (POM), polyimide (PI), polyphenylene sulfide (PPS), polyethylene (PE), polyetherimide (PEI), polyethylene terephthalate (PET), MC nylon, polyphenylene oxide (PPO), carbon fiber (CF), glass fiber (GF), aramid fiber, and corresponding modified products; Lubricating oil / grease: 5% - 70%; Filler: 0% - 15%, selected from one or more of molybdenum disulfide, nano-silica, graphite, hexagonal boron nitride, short carbon fiber / glass fiber, toughening agent; Auxiliary agent: 1% - 15%, selected from one or more of antioxidant, dispersant, anti-ultraviolet agent, toughening agent, coupling agent.

[0006] As the first preferred embodiment of the present invention, it comprises the following components by weight percentage: UPE: 40% - 80%, synthetic grease: 15% - 50%, molybdenum disulfide: 3% - 8%, short carbon fiber (length 0.1 - 1 mm): 5% - 10%, nano-silica (particle size 20 - 50 nm): 2% - 5%, silane coupling agent (KH-550): 1% - 2%, antioxidant 1010: 0.3% - 0.8%, dispersant polyethylene wax: 0.5% - 1%. Continuous lubrication is achieved through the synergistic effect of high-content silicon-based grease and molybdenum disulfide, short carbon fiber enhances mechanical strength, and nano-silica improves wear resistance, which is suitable for friction-reducing and wear-resistant parts. Its preparation process is as follows: The specific process includes: In the preparation stage of the premix, the dried UPE resin is premixed with short carbon fiber, nano-silica and molybdenum disulfide treated with KH-550, and then mixed with the 60°C molten synthetic grease at low temperature by infiltration to form a paste; in the loading stage, a chromium-plated steel mold is used and sprayed with PTFE release agent, and after preheating at 80°C, it is pre-pressed at 5 MPa to remove air bubbles; the hot pressing stage is implemented in three steps. First, the temperature is raised to 180°C and pressurized at 15 MPa for 15 minutes to achieve matrix melting, then the temperature is raised to 200°C and the pressure is increased to 25 MPa and maintained for 20 minutes to complete plasticization and fiber orientation, and finally it is slowly cooled to 100°C for demolding (cooling rate ≤ 2°C / min); the post-treatment is to cure the surface lubricating layer by heat treatment at 100°C for 4 hours. The core advantage of the molding process is to reduce the damage to the molecular chain of the grease caused by high-temperature shear, and static pressure avoids phase separation of high grease content, especially in the case of containing a large amount of fiber and grease, molding can better control the flow and distribution of materials and avoid grease migration or fiber breakage during the injection molding process.

[0007] As the second preferred solution of the present invention, it comprises the following components by weight percentage: PEI: 50%-85%, perfluoropolyether grease: 10%-30%, graphite (flake diameter 5-20 μm): 5%-10%, PTFE powder (particle size 1-10 μm): 3%-5%, titanate coupling agent (NDZ-201): 1%-3%, antioxidant 168: 0.5%-1%, nano-aluminum oxide (enhancing wear resistance): 2%-4%. The perfluoropolyether grease and PTFE form a low-friction interface, and graphite provides interlayer lubrication for components with a temperature resistance of over 200°C.

[0008] Its preparation process is as follows: First, the perfluoropolyether grease and PTFE powder (1-10 μm) are cryogenically pulverized (-20°C) to make microcapsule powder (particle size 50-80 μm) to prevent lipid agglomeration; then PEI powder is added and dry-mixed with the PTFE microcapsule powder for 15 min, and sprayed into a nano-aluminum oxide suspension (atomization pressure 0.3 MPa) for synchronous mixing for 20 min. Finally, activated graphite flakes and antioxidant 168 are added, and mixing is continued for 30 min until the angle of repose < 35°; the mixture is sieved by vibration (mesh number 200) to remove lumps, and a homogeneous powder with a flowability index > 75 is obtained. The powder is loaded into a mold and isostatically pressed at 200 MPa for 2 min to make a preform with a relative density of 85%; then stepwise hot pressing and sintering: In the first stage, it is heated to 280°C at a rate of 5°C / min and kept at 10 MPa for 30 min to remove volatile components; in the second stage, it is heated to 340°C (120°C above the PEI Tg) and pressurized to 30 MPa, and kept under pressure for 60 min to achieve densification; in the third stage: cooled at a controlled rate (1°C / min) to 180°C and then demolded to obtain a near-net-shaped part. Finally, annealing treatment (260°C × 4 h) is carried out in a nitrogen atmosphere to eliminate interfacial microcracks.

[0009] As the third preferred solution of the present invention, it comprises the following components by weight percentage: PA66: 50%-85%, synthetic hydrocarbon grease (viscosity index > 120): 10%-40%, PTFE powder (particle size 5-15 μm): 5%-12%, chopped glass fiber (diameter 10 μm, length 0.5-3 mm): 8%-15%, graphene nanosheet (thickness < 5 nm, flake diameter 1-5 μm): 1%-3%, titanate coupling agent (NDZ-311): 1%-2%, antioxidant 1098: 0.5%-1%, nano-silicon nitride (enhancing interfacial bonding): 2%-5%. Through the synergy of synthetic hydrocarbon grease and PTFE to form a dynamic lubrication network, combined with the multi-level reinforcement of glass fiber / graphene and the interface optimization of nano-silicon nitride, high oil content and low friction coefficient are achieved, which are suitable for low-noise and high-precision wear-resistant components.

[0010] The preparation process is as follows: PA66 particles are vacuum dried at 105°C for 12 hours (water content ≤ 0.1%); synthetic hydrocarbon grease and PTFE powder are made into microcapsule particles (particle size 100 - 150 μm, grease content 55%) by spray freeze drying; chopped glass fibers (0.5 - 3 mm) are treated with a silane coupling agent (KH-550); the graphene / nano silicon nitride composite filler forms a core-shell structure through ball milling. The PA66 powder, microcapsule particles, glass fibers and composite filler are dry mixed step by step using a three-dimensional mixer (rotation speed 18 rpm), and zinc stearate (0.5%) is added to improve fluidity, obtaining a homogeneous powder with a repose angle < 30°. The powder is loaded into a mold and pre-pressed into a green body with a relative density of 82% under a pressure of 200 MPa. Stepwise hot pressing sintering: In the devolatilization stage, it is heated to 230°C (below the melting point of PA66) at a rate of 5°C / min, pressurized at 10 MPa and held for 30 min to remove volatiles; in the melting densification stage, it is heated to 270°C (5°C above the melting point of PA66), the pressure is increased to 30 MPa, and the pressure is held for 60 min to achieve interfacial bonding; temperature-controlled cooling: it is slowly cooled to 100°C at a rate of 1°C / min and demolded to inhibit crystallization stress. Post-treatment strengthening: annealing at 140°C for 6 hours.

[0011] The oil-containing polymer composite material of the present invention has the characteristics of long life, small friction coefficient, low vibration, low noise, small starting torque and high reliability. Under normal working conditions and alternating load, it can form good lubrication; under impact load, it can reduce the jitter of the friction pair and slow down the wear problem. The present invention realizes continuous lubrication through the synergistic effect of high-oil-content grease and molybdenum disulfide, enhances the mechanical strength with chopped carbon fibers, improves the wear resistance with nano-silica, reduces the maintenance cost and improves the reliability and service life of the equipment.

[0012] The oil-containing polymer composite material of the present invention has the following beneficial effects: 1. Excellent self-lubricating performance: By adding lubricating oil or grease to the polymer matrix material, the lubricating performance of the material is significantly improved, and the friction and wear between mechanical components are reduced. Good mechanical strength: The selection and optimization of the polymer matrix material ensure the strength and stability of the material under the use load environment. Excellent processing performance: The material of the present invention can be formed by conventional processing methods such as extrusion, vulcanization, injection molding, etc., and has good processing adaptability. Long service life: Due to the self-lubricating performance of the material, equipment failures caused by insufficient lubrication are reduced, and the service life of mechanical components is extended.

[0013] 2. Through the synergistic effect of the above components, the present invention breaks through the technical bottleneck of "high oil must be low strength" of traditional high-oil materials through four core innovations: quaternary matrix synergistic modification, gradient structure design, dynamic interface regulation and long-term lubrication mechanism, and realizes the synergistic optimization of high temperature resistance (250°C), high strength (92 MPa) and high oil content (30%). To more clearly illustrate the structural features and functions of the present invention, the present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments. Description of the Drawings

[0014] Figure 1 is the polymer composite skateboard of the present invention, which is marked as 1.

[0015] Figure 2 is the polymer composite bar stock of the present invention, which is marked as 2.

[0016] Figure 3 is the polymer composite bushing of the present invention, which is marked as 3.

[0017] Figure 4 is the polymer composite gear of the present invention, which is marked as 4. Detailed Description of the Embodiments

[0018] The present invention will be further described below in conjunction with the accompanying drawings and relevant knowledge, and will be described clearly and completely. Obviously, the described applications are only a part of the embodiments of the present invention, rather than all the embodiments. Embodiment 1

[0019] See Figures 1 - 2 the skateboard and bar stock made; as a preferred solution of the present invention, it includes the following components by weight percentage: UPE: 40%-80%, synthetic lubricating grease: 15%-50%, molybdenum disulfide: 3%-8%, short-cut carbon fiber (length 0.1-1 mm): 5%-10%, nano-silica (particle size 20-50 nm): 2%-5%, silane coupling agent (KH-550): 1%-2%, antioxidant 1010: 0.3%-0.8%, dispersant polyethylene wax: 0.5%-1%.

[0020] Continuous lubrication is achieved through the synergistic effect of high-content silicon-based lubricating grease and molybdenum disulfide, the mechanical strength is enhanced by short-cut carbon fiber, and the wear resistance is improved by nano-silica, which is suitable for making friction-reducing and wear-resistant parts.

[0021] Its preparation process is as follows: In the preparation stage of the premix, the dried UPE resin is premixed with short carbon fibers treated with KH-550, nano-silica and molybdenum disulfide, and then mixed with 60 °C molten synthetic grease by low-temperature penetration to form a paste; in the loading stage, a chromium-plated steel mold is used and PTFE release agent is sprayed. After preheating at 80 °C, bubbles are removed by pre-pressing at 5 MPa; the hot pressing stage is carried out in three steps. First, the temperature is raised to 180 °C and the pressure is increased to 15 MPa for 15 minutes to achieve matrix melting. Then, the temperature is raised to 200 °C and the pressure is increased to 25 MPa and maintained for 20 minutes to complete plasticization and fiber orientation. Finally, it is slowly cooled to 100 °C for demolding (cooling rate ≤ 2 °C / min); the post-treatment is carried out by heat treatment at 100 °C for 4 hours to cure the surface lubricating layer.

[0022] The core advantage of the molding process lies in reducing the damage to the grease molecular chain caused by high-temperature shearing. Static pressing avoids phase separation of high grease content, especially in the case of containing a large amount of fibers and grease. Molding can better control the flow and distribution of materials and avoid grease migration or fiber breakage that may occur during the injection molding process. Example 2

[0023] As Figure 3 shown in the sliding bearing bush, as a preferred solution of the present invention, it comprises the following components by weight percentage: PEI: 50%-85%, perfluoropolyether grease: 10%-30%, graphite (flake diameter 5-20 μm): 5%-10%, PTFE powder (particle size 1-10 μm): 3%-5%, titanate coupling agent (NDZ-201): 1%-3%, antioxidant 168: 0.5%-1%, nano-aluminum oxide (enhancing wear resistance): 2%-4%. The perfluoropolyether grease and PTFE form a low-friction interface, and graphite provides interlayer lubrication for parts with a temperature resistance above 200 °C.

[0024] The preparation process is as follows: First, perfluoropolyether grease and PTFE powder (1 - 10 μm) are cryogenically pulverized at -20°C to form microcapsule powder (particle size 50 - 80 μm) to prevent lipid agglomeration. Then, PEI powder is added and dry-mixed with the PTFE microcapsule powder for 15 min, and then sprayed into a nano-aluminum oxide suspension (atomization pressure 0.3 MPa) for synchronous mixing for 20 min. Finally, activated graphite flakes and antioxidant 168 are added, and mixing is continued for 30 min until the angle of repose < 35°. The mixture is subjected to vibrating screening (mesh number 200) to remove lumps, and a homogeneous powder with a flowability index > 75 is obtained. The powder is loaded into a mold and isostatically pressed at 200 MPa for 2 min to form a preform with a relative density of 85%. Then, stepwise hot pressing and sintering are carried out: In the first stage, the temperature is raised to 280°C at a rate of 5°C / min, and the volatiles are removed by holding at 10 MPa for 30 min. In the second stage, the temperature is raised to 340°C (120°C above the PEI Tg) and the pressure is increased to 30 MPa, and densification is achieved by holding for 60 min. In the third stage: The temperature is controlled to cool (1°C / min) to 180°C and then demolded to obtain a near-net-shaped part. Finally, annealing treatment (260°C × 4 h) is carried out in a nitrogen atmosphere to eliminate interfacial microcracks.

[0025] Through the comparative test of the sliding bearing sleeve formed by molding and the ordinary engineering plastic bearing, it is found that: the friction coefficient of the oil-containing polymer material is significantly lower, the self-lubricating performance is better, the wear amount is smaller, the shock absorption and noise reduction effect is better, the replacement frequency is reduced, and it is suitable for long-term maintenance-free operation.

[0026] Performance indicators Test conditions Oil - containing polymer composite bushing Ordinary engineering plastic bushing Self - lubricating performance Coefficient of friction test (dry friction, load 100 N, speed 0.5 m / s) Coefficient of friction: 0.078 Coefficient of friction: 0.120 Wear resistance Wear test (load 300 N, contact pressure 1.2 MPa, running time 100 hours) Wear amount: 0.05 mm Wear amount: 0.15 mm Vibration damping and noise reduction Noise test (running speed 1500 rpm, load 200 N) Noise level: 65 dB Noise level: 72 dB Service life Service life test (high - load start - stop cycle test, load 500 N, start - stop frequency 10 times / minute) Service life: 5000 hours Service life: 3000 hours Maintenance cost Maintenance test (maintenance requirements after running 1000 hours) No additional lubrication required, low maintenance cost Regular lubrication required, high maintenance cost Example 3

[0027] As Figure 4 shown in the gear, as a preferred embodiment of the present invention, it comprises the following components by weight percentage: PA66: 50% - 85%, synthetic hydrocarbon lubricating grease (viscosity index > 120): 10% - 40%, PTFE powder (particle size 5 - 15 μm): 5% - 12%, chopped glass fiber (diameter 10 μm, length 0.5 - 3 mm): 8% - 15%, graphene nanosheet (thickness < 5 nm, sheet diameter 1 - 5 μm): 1% - 3%, titanate coupling agent (NDZ-311): 1% - 2%, antioxidant 1098: 0.5% - 1%, nano-silicon nitride (enhancing interface bonding): 2% - 5%. It is characterized in that: a dynamic lubrication network is formed by the synergy of synthetic hydrocarbon lubricating grease and PTFE, combined with the multi-stage reinforcement of glass fiber / graphene and the interface optimization of nano-silicon nitride, to achieve high oil content and low friction coefficient, and is applicable to low-noise and high-precision wear-resistant components.

[0028] The preparation process is as follows: PA66 particles are vacuum dried at 105°C for 12 hours (water content ≤ 0.1%); synthetic hydrocarbon grease and PTFE powder are made into microcapsule particles (particle size 100 - 150 μm, grease content 55%) by spray freeze drying; chopped glass fibers (0.5 - 3 mm) are treated with a silane coupling agent (KH-550); the graphene / nano-silicon nitride composite filler forms a core-shell structure through ball milling. The PA66 powder, microcapsule particles, glass fibers and composite filler are dry mixed step by step using a three-dimensional mixer (rotation speed 18 rpm), and zinc stearate (0.5%) is added to improve fluidity, obtaining a homogeneous powder with a repose angle < 30°. The powder is loaded into a mold and pre-pressed into a green body with a relative density of 82% under a pressure of 200 MPa. Stepwise hot pressing and sintering: In the devolatilization stage, it is heated to 230°C (below the melting point of PA66) at a rate of 5°C / min, pressurized to 10 MPa and held for 30 min to remove volatiles; in the melting densification stage, it is heated to 270°C (5°C above the melting point of PA66), the pressure is increased to 30 MPa, and the pressure is held for 60 min to achieve interfacial bonding; temperature-controlled cooling: slowly cooled to 100°C at a rate of 1°C / min and demolded to inhibit crystallization stress. Post-treatment strengthening: annealed at 140°C for 6 hours. Then the cooled and shaped disc-shaped green body is fixed on a hobbing machine and processed into the required gear shape through the hobbing process.

[0029] The self-lubricating performance of the oil-containing polymer composite gear is strong. During operation, it can significantly reduce the friction coefficient, reduce wear, and does not require external lubricating oil; it has good wear resistance and a long service life; it reduces vibration and noise.

[0030] In summary, through the optimization of the material formula and processing technology, the oil-containing polymer composite gear has achieved multiple advantages such as self-lubrication, wear resistance, shock absorption, noise reduction, lightweight and corrosion resistance. It has significant innovation and practicality.

[0031] The technical principle of the present invention has been described above in combination with specific embodiments, which are only the preferred embodiments of the present invention. The protection scope of the present invention is not limited to the above embodiments. All technical solutions within the idea of the present invention belong to the protection scope of the present invention. Those skilled in the art can think of other specific embodiments of the present invention without creative labor, and these embodiments will fall within the protection scope of the present invention.

Claims

1. An oil-containing polymer composite material with high oil yield, characterized in that: It is composed of the following components by weight percentage: Polymer matrix material: 10%-90%, the polymer matrix material is selected from one or more of ultra-high molecular weight polyethylene (UPE), polytetrafluoroethylene (PTFE), polyetheretherketone (PEEK), polyamide (PA6), polyamide-imide (PAI), polyoxymethylene (POM), polyimide (PI), polyphenylene sulfide (PPS), polyethylene (PE), polyetherimide (PEI), polyethylene terephthalate (PET), MC nylon, polyphenylene oxide (PPO), carbon fiber (CF), glass fiber (GF), aramid fiber, and corresponding modified substances; Lubrication system: 5%-70%; Filler: 0%-15%, the filler is selected from one or more of molybdenum disulfide, nano-silicon dioxide, graphite, hexagonal boron nitride, chopped carbon fiber / glass fiber, and toughening agent; Additives: 1%-15%, selected from one or more of antioxidants, dispersants, UV inhibitors, toughening agents, and coupling agents.

2. The oil-containing polymer composite material with high oil yield as claimed in claim 1, characterized in that: The polymer matrix material includes ultra-high molecular weight polyethylene, polyamide, polyoxymethylene, polyetheretherketone, polytetrafluoroethylene, polyimide, polyetherimide, polyethylene terephthalate, and MC nylon.

3. The oil-containing polymer composite material with high oil yield as claimed in claim 1, characterized in that: The lubrication system includes: lubricating grease, molybdenum disulfide, graphite, and PTFE powder; the filler includes short-cut carbon fiber and nano-silicon dioxide; and the additives include coupling agents, antioxidants, and dispersants.

4. The oil-containing polymer composite material with high oil yield as claimed in claim 1, characterized in that: The invention comprises the following components by weight percentage: UPE: 40%-80%, synthetic grease: 15%-50%, molybdenum disulfide: 3%-8%, chopped carbon fiber: 5%-10%, nano silicon dioxide: 2%-5%, silane coupling agent: 1%-2%, antioxidant 1010: 0.3%-0.8%, and dispersant polyethylene wax: 0.5%-1%.

5. The oil-containing polymer composite material with high oil yield as claimed in claim 1, characterized in that: The following components are included in percentage by weight Composition: PEI: 50%-85%, perfluoropolyether grease: 10%-30%, graphite: 5%-10%, PTFE powder: 3%-5%, titanate coupling agent: 1%-3%, antioxidant 168: 0.5%-1%, nano-alumina: 2%-4%.

6. The oil-containing polymer composite material with high oil yield as claimed in claim 1, characterized in that: The following components are included in percentage by weight Composition: PA66: 50%-85%, synthetic hydrocarbon grease: 10%-40%, PTFE powder: 5%-12%, chopped glass fiber: 8%-15%, graphene nanosheets: 1%-3%, titanate coupling agent: 1%-2%, antioxidant 1098: 0.5%-1%, nano-silicon nitride: 2%-5%.

7. A method for preparing an oil-containing polymer composite material with a high oil yield as claimed in claim 1, characterized in that: It includes molding, casting, vulcanization, extrusion or injection molding; the polymer matrix material is melted by heating and pressurizing to obtain the oil-containing polymer composite material in the desired shape.

8. A molding method for an oil-containing polymer composite material with a high oil yield as claimed in claim 1, characterized in that: The compression molding process can reduce the damage to the grease molecular chain caused by high temperature shearing, and static pressurization can avoid phase separation of high grease content, thus avoiding grease migration or fiber breakage during the injection molding process.

Images