Wear-resistant rubber-plastic composite material for high-pressure air pipe and production method thereof

Abstract

The invention relates to the field of high polymer materials, and particularly discloses a rubber-plastic composite material for a wear-resistant high-pressure air pipe and a production method of the rubber-plastic composite material. The composite material comprises the following raw materials in parts by weight: 100 parts of PVC; 36-45 parts of a plasticizer; 4-6 parts of a stabilizer; 8 to 13 parts of polytetrafluoroethylene; 3 to 6 parts of nano silicon dioxide; 22 to 30 parts of TPU (Thermoplastic Polyurethane); 23 to 30 parts of butyronitrile powder; and 2-4 parts of a lubricant. The production method comprises the following steps: uniformly mixing the raw materials according to the ratio, and extruding and granulating. The composite material has the advantage of high wear resistance.

Description

Technical Field

[0001] The present application relates to the field of polymer materials, and more specifically, to a wear-resistant rubber-plastic composite material for high-pressure air pipes and a production method thereof. Background Art

[0002] High-pressure gas pipe is a pipeline system used to transport high-pressure gases (such as compressed air, nitrogen, natural gas, etc.), which is widely used in industry, automobile, aerospace, medical equipment and other fields.

[0003] When in use, the high-pressure air pipe often needs to be dragged, which creates a lot of friction with the ground, making the PVC sheath covering the outer surface of the high-pressure air pipe easily worn out. Therefore, a more wear-resistant material is needed to cover the high-pressure air pipe. Summary of the invention

[0004] In order to improve the wear resistance of high-pressure air pipe sheath materials, the present application provides a wear-resistant rubber-plastic composite material for high-pressure air pipes and a production method thereof.

[0005] In the first aspect, the present application provides a wear-resistant rubber-plastic composite material for high-pressure air pipes, which adopts the following technical solution: A wear-resistant rubber-plastic composite material for high-pressure air pipes, comprising the following raw materials in parts by weight: PVC 100 copies; 36-45 parts of plasticizer; 4-6 parts of stabilizer; 8-13 parts of polytetrafluoroethylene; 3-6 parts of nano silicon dioxide; TPU 22-30 parts; 23-30 parts of nitrile powder; 2 to 4 parts of lubricant.

[0006] By adopting the above technical solution, due to the use of TPU and nitrile powder, the polar acrylonitrile group of nitrile powder has good compatibility with PVC, which can significantly improve the impact toughness of PVC materials; the high elasticity and wear resistance of TPU further enhance the tensile strength of PVC materials. The combination of TPU's wear resistance and nitrile powder's oil resistance makes the composite material perform better in high-pressure air pipe scenarios. In addition, nitrile powder can be used as a substitute for some liquid plasticizers. Its polar molecular structure can inhibit the migration of plasticizers through physical adsorption or chemical bonding, reduce the risk of precipitation, and can effectively reduce the wear of composite materials and improve their wear resistance. In terms of processing convenience, nitrile powder is a non-extrusion plasticizer that can be directly blended with PVC to reduce processing steps; the thermoplastic properties of TPU facilitate extrusion molding, and the compounding of the two can achieve process compatibility.

[0007] Optionally, the rubber-plastic composite material comprises the following raw materials in parts by weight: PVC 100 copies; 40 parts of plasticizer; 5 parts of stabilizer; 10 parts of polytetrafluoroethylene; 5 parts of nano silicon dioxide; TPU 25 parts; 25 parts of nitrile powder; 3 parts of lubricant.

[0008] By adopting the above technical solution, the composite material obtained with the above ratio has better wear resistance.

[0009] Optionally, the plasticizer is DOTP.

[0010] Optionally, the stabilizer is a calcium zinc stabilizer.

[0011] Optionally, the lubricant is polyethylene wax.

[0012] Optionally, the rubber-plastic composite material further comprises the following raw materials in parts by weight: PEEK micro powder 0.5-1 part; Phase change microcapsule PCM 0.8-1.2 parts; 1 to 1.5 parts of carbon nanotubes.

[0013] By adopting the above technical solution, the surface energy of PVC material is high, which makes it easy to adhere to other substances, so it is easy to wear during the dragging process. Carbon nanotubes can give the composite material better electrical conductivity and thermal conductivity, transfer heat to the phase change microcapsule PCM to be absorbed, and its own temperature does not change much. When PCM microcapsules are added to the composite material, PCM can be used to absorb excess heat when friction generates heat, and then slowly released when the ambient temperature drops, which helps to reduce the damage of heat to the composite material. At the same time, PEEK micropowder can be used as a bridging agent to help disperse carbon nanotubes, help break the agglomeration phenomenon between carbon nanotubes, and promote their uniform distribution in the composite material. Due to its high aspect ratio and surface activity, carbon nanotubes can form a three-dimensional network structure in the composite matrix. This network structure can help stabilize PEEK micropowder and prevent them from re-aggregating. The self-lubricating property of PEEK micropowder can significantly reduce the friction coefficient of the composite material and provide the composite material with higher wear resistance.

[0014] Optionally, the carbon nanotubes are surface-modified carbon nanotubes.

[0015] By adopting the above technical solution, the surface-modified carbon nanotubes can enhance the compounding advantages with PEEK micropowder and phase change microcapsule PCM, be better dispersed in the composite material, form a stable three-dimensional network structure, and improve the wear resistance of the composite material.

[0016] In a second aspect, the present application provides a method for producing a wear-resistant rubber-plastic composite material for a high-pressure air pipe, which adopts the following technical solution: A method for producing a wear-resistant rubber-plastic composite material for a high-pressure air pipe comprises the following steps: taking raw materials according to a ratio, mixing them uniformly, and then extruding and granulating them.

[0017] By adopting the above technical solution, the prepared composite material has excellent wear resistance.

[0018] In summary, this application has the following beneficial effects: 1. Since the present application adopts TPU and nitrile powder compound, the polar acrylonitrile group of nitrile powder has good compatibility with PVC, which can significantly improve the wear resistance of PVC materials; the high elasticity and wear resistance of TPU further enhance the strength of PVC materials. The combination of TPU and nitrile powder makes the composite material perform better in the scenario of high-pressure air pipes; 2. In this application, it is preferred to use a compound of PEEK micropowder, phase change microcapsules PCM and carbon nanotubes (CNTs). Carbon nanotubes can give the composite material better thermal conductivity, transfer heat to the phase change microcapsules PCM to be absorbed, and the composite material uses PCM to absorb excess heat when friction generates heat, and then slowly releases it when the ambient temperature drops, which helps to reduce heat damage to the composite material. At the same time, PEEK micropowder can act as a bridging agent to help disperse carbon nanotubes and promote their uniform distribution in the composite material. Carbon nanotubes can form a three-dimensional network structure in the composite matrix, which can help stabilize PEEK micropowder and prevent them from re-aggregating. The effect of improving the wear resistance of the composite material is achieved; 3. The composite material prepared by the method of the present application has excellent wear resistance. DETAILED DESCRIPTION

[0019] The present application is further described in detail with reference to the following examples. It is specially noted that if no specific conditions are specified in the following examples, the conventional conditions or the conditions recommended by the manufacturer are followed, and the raw materials used in the following examples can be obtained from common commercial sources unless otherwise specified.

[0020] PVC, model SG-5, brand Xinjiang Tianye.

[0021] DOTP, dioctyl terephthalate, active ingredient content 99%.

[0022] Calcium zinc stabilizer, liquid compound type, superior grade, brand Rongren Chemical.

[0023] Polytetrafluoroethylene, particle size 10μm.

[0024] Nano-silicon dioxide, 12 mesh.

[0025] TPU, particle size 0.5mm, BASF 1085A.

[0026] Nitrile powder, 100 mesh, acrylonitrile content 33% to 36%.

[0027] Polyethylene wax, brand Yi Teng Chemical, melting point range 90~116℃.

[0028] PEEK micro powder, Victrex L150 (fine powder).

[0029] Phase change microcapsules PCM, industrial grade, particle size 5 μm, temperature 28 °C, purchased from Hebei Ruosen Technology Co., Ltd.

[0030] Carbon nanotubes (CNTs), brand GTR-300, with an aspect ratio of 800-1 000, were purchased from Qingdao Taige New Material Technology Co., Ltd.

[0031] Methacrylic acid (MAA) was purchased from Xi'an Tianmao Chemical Co., Ltd.

[0032] Example of preparation of surface-modified carbon nanotubes.

[0033] Preparation Example 1 (1) Raw material preparation: Carbon nanotubes (CNTs), 1 g; white carbon black, 0.5 g; methacrylic acid (MAA), 1.5 g; zinc oxide (ZnO), 0.5 g.

[0034] CNTs pretreatment: CNTs were soaked in a mixture of concentrated sulfuric acid and nitric acid (3:1 volume ratio), treated with ultrasound (40kHz) at 80°C for 2 hours, centrifuged and washed to neutrality after carboxyl modification, and vacuum dried at 60°C to obtain acidified CNTs. The acidified CNTs and silane coupling agent (KH-570) were ultrasonically dispersed in ethanol for 30 minutes, dried at 80°C for use, and the weight of KH-570 was 0.5% of the acidified CNTs. The amount of ethanol needed to cover the surface of the CNTs.

[0035] (2) Premixing: Add the acidified CNTs and 40% of the total amount of MAA (0.6 g) into a high-speed shear mixer; heat to 60 °C and shear at 1500 rpm for 5 min to form a uniform slurry. The slurry viscosity is controlled at 4000 mPa·s (Brookfield viscometer, rotor 3#, 30 rpm).

[0036] (3) Add ZnO and silica in steps: Dry-mix ZnO and silica in advance to reduce agglomeration; add the ZnO / silica mixture three times at an interval of 2 minutes while maintaining a speed of 1500 rpm; after each addition, increase the speed to 2000 rpm and maintain for 1 minute to ensure uniform dispersion.

[0037] (4) In situ reaction and coating: Raise the temperature to 85±2℃ and reduce the rotation speed to 1200 rpm; slowly add the remaining 60% of MAA (0.9 g) through a constant pressure dropping funnel, and control the dropping rate to 0.5 mL / min; the reaction time is 35±5 minutes, until the pH of the system stabilizes at 6.8±2 (MAA and ZnO react completely to form zinc methacrylate, which combines with the carboxyl groups on the surface of CNTs through ionic bonds to form a dense coating layer).

[0038] (5) Post-treatment: After the reaction is completed, cool to 40 °C and add deionized water to dilute to a solid content of 10%; separate the product by centrifugation (8000 rpm, 15 min) and wash with ethanol three times to remove unreacted monomers; vacuum freeze-dry (-50 °C, 24 h) to avoid cracking of the coating layer due to high temperature.

[0039] Example

[0040] Example 1 A wear-resistant rubber-plastic composite material for high-pressure air pipes, comprising the following raw materials: PVC; plasticizer, DOTP; stabilizer, calcium zinc stabilizer; polytetrafluoroethylene, powder; nano silicon dioxide; TPU; nitrile powder; lubricant, polyethylene wax. The amount of each raw material is shown in Table 1.

[0041] A method for producing a wear-resistant rubber-plastic composite material for a high-pressure air pipe comprises the following steps: (1) Raw material pretreatment: PVC: Pass through an 80-mesh sieve to remove lumps and dry in an oven at 80°C for 2 hours (until the moisture content is ≤0.3%).

[0042] DOTP: Preheat to 60°C to reduce viscosity and facilitate uniform dispersion.

[0043] Nano-silica: Pre-disperse with silane coupling agent (KH-550) at a dosage of 0.5% of nano-silica in a high-speed mixer for 5 minutes at a speed of 800 rpm.

[0044] Polytetrafluoroethylene: Mix and grind with calcium stearate at a dosage of 1% of polytetrafluoroethylene to reduce electrostatic agglomeration.

[0045] (2) High-speed mixing: Set the speed of the high-speed mixer to 1000rpm, heat the jacket, and mix the raw materials evenly in the following order: add PVC and heat to 60℃; add calcium zinc stabilizer and DOTP and mix for 3 minutes; add nano-silica, TPU, and nitrile powder and heat to 90℃ and mix for 5 minutes; add polytetrafluoroethylene and polyethylene wax and heat to 110℃ and mix for 8 minutes. End point control: the material temperature reaches 110℃ and is in a loose mass.

[0046] (3) Cooling and mixing: The high-speed mixed material was transferred to a low-temperature cooling mixer, cooled to 45°C, with a rotation speed of 800 rpm, and a water-cooled jacket, and mixed for 10 minutes to prevent the hot material from agglomerating.

[0047] (4) Extrusion granulation: Use a twin-screw extruder (L / D=40:1, screw combination: high shear zone + multi-stage exhaust), the temperature setting is: zone 1 150℃, zone 2 165℃, zone 3 175℃, zone 4 180℃, zone 5 175℃, die 170℃. Screw speed 280±20 rpm; feed rate needs to match screw speed to ensure 85% filling rate; vacuum degree -0.08MPa is set after zone 2 to remove volatiles; die pressure 15MPa to ensure uniform extrusion of melt. After extrusion, cool and pelletize at 25℃, size φ3*3mm, dry in a fluidized bed dryer at 50℃ for 1 hour to make the moisture content ≤0.1%, sieve to remove large particles and debris, and seal and store in bags.

[0048] Example 2 The difference between this embodiment and embodiment 1 is that the amounts of various raw materials are different, see Table 1 for details.

[0049] Example 3 The difference between this embodiment and embodiment 1 is that the amounts of various raw materials are different, see Table 1 for details.

[0050] Example 4 The difference between this embodiment and embodiment 2 is that the raw materials of this embodiment further include PEEK powder, phase change microcapsules PCM and carbon nanotubes (CNTs), and the usage is detailed in Table 1.

[0051] The difference between the production method and Example 2 is: (1) Raw material pretreatment: PEEK micropowder needs to be vacuum dried at 150°C for 3 hours before adding to prevent hydrolysis during high-temperature processing.

[0052] (2) High-speed mixing: Addition order: add PVC, calcium zinc stabilizer, DOTP, mix at 60°C for 3 minutes; add TPU, nitrile powder, nano-silica, mix at 90°C for 5 minutes; cool to 70°C, add polytetrafluoroethylene and PEEK powder, mix at 1200 rpm for 3 minutes; add carbon nanotubes, high-speed shear at 2000 rpm for 5 minutes; cool to 50°C, add phase change microcapsules PCM and polyethylene wax, and mix at a low speed of 800 rpm for 2 minutes.

[0053] (3) Cooling and mixing: Cool the mixer down to 35°C.

[0054] (4) Extrusion granulation: A twin-screw extruder (L / D=44:1, screw combination: strong shear + slow release zone) was used, and the temperature was set as follows: 145℃ in zone 1, 160℃ in zone 2, 170℃ in zone 3, 175℃ in zone 4, 170℃ in zone 5, and 165℃ in die head. The screw speed was 240±20 rpm; the feeding rate needed to match the screw speed to ensure a filling rate of 85%; two-stage vacuum (-0.08 MPa to -0.09 MPa) was set in zone 3 to remove volatiles; the die head pressure was 12MPa to ensure uniform extrusion of the melt. After extrusion, the pellets were cooled and granulated at 20℃ and φ3*3mm in size. They were dried in a fluidized bed dryer at 40℃ for 1 hour to make the moisture content ≤0.1%, and large particles and debris were removed by sieving, and the pellets were sealed and stored in bags.

[0055] Example 5 The difference between this embodiment and embodiment 4 is that the amounts of various raw materials are different, see Table 1 for details.

[0056] Example 6 The difference between this embodiment and embodiment 4 is that the amounts of various raw materials are different, see Table 1 for details.

[0057] Example 7 The difference between this embodiment and embodiment 5 is that there is no PEEK powder in this embodiment.

[0058] Example 8 The difference between this embodiment and embodiment 5 is that there is no phase change microcapsule PCM in this embodiment.

[0059] Example 9 The difference between this embodiment and embodiment 5 is that there are no carbon nanotubes in this embodiment.

[0060] Example 10 The difference between this embodiment and embodiment 5 is that there is no PEEK powder and phase change microcapsule PCM in this embodiment.

[0061] Embodiment 11 The difference between this embodiment and embodiment 5 is that there is no PEEK powder and carbon nanotubes in this embodiment.

[0062] Example 12 The difference between this embodiment and embodiment 5 is that there are no phase change microcapsules PCM and carbon nanotubes in this embodiment.

[0063] Embodiment 13 The difference between this embodiment and embodiment 5 is that the carbon nanotubes in this embodiment are the surface-modified carbon nanotubes prepared in preparation example 1.

[0064] Comparative example.

[0065] Comparative Example 1 The difference between this comparative example and Example 2 is that the raw materials of this comparative example do not contain TPU and nitrile powder.

[0066] Comparative Example 2 The difference between this comparative example and Example 2 is that there is no TPU in the raw materials of this comparative example.

[0067] Comparative Example 3 The difference between this comparative example and Example 2 is that there is no nitrile powder in the raw materials of this comparative example.

[0068] Table 1 Amounts of raw materials used in various examples and comparative examples PVC / g DOTP / g Calcium zinc stabilizer / g Polytetrafluoroethylene / g Nano silicon dioxide / g TPU / g Nitrile powder / g Polyethylene wax / g PEEK powder / g Phase change microcapsule PCM / g Carbon nanotubes / g Modified carbon nanotubes / g Example 1 100 36 4 8 3 22 23 2 0 0 0 0 Example 2 100 40 5 10 5 25 25 3 0 0 0 0 Example 3 100 45 6 13 6 30 30 4 0 0 0 0 Example 4 100 40 5 10 5 25 25 3 0.5 0.8 1 0 Example 5 100 40 5 10 5 25 25 3 0.7 1 1.2 0 Example 6 100 40 5 10 5 25 25 3 1 1.2 1.5 0 Example 7 100 40 5 10 5 25 25 3 0 1 1.2 0 Example 8 100 40 5 10 5 25 25 3 0.7 0 1.2 0 Example 9 100 40 5 10 5 25 25 3 0.7 1 0 0 Example 10 100 40 5 10 5 25 25 3 0 0 1.2 0 Embodiment 11 100 40 5 10 5 25 25 3 0 1 0 0 Example 12 100 40 5 10 5 25 25 3 0.7 0 0 0 Example 13 100 40 5 10 5 25 25 3 0.7 1 0 1.2 Comparative Example 1 100 40 5 10 5 0 0 3 0 0 0 0 Comparative Example 2 100 40 5 10 5 0 25 3 0 0 0 0 Comparative Example 3 100 40 5 10 5 25 0 3 0 0 0 0

[0069] Performance testing test.

[0070] Detection method.

[0071] 1. Wear resistance: The particles obtained from the above embodiments and comparative examples were extruded into a sheath of a high-pressure air pipe with a diameter of 12.0 mm. Linear wear was performed using a Taber 5750 linear abraser, with a die head of 15×15 mm, a grinding surface with P600 sandpaper, a load of 350 g, a cycle of 50 times / min, and a stroke of 100 mm. A 200 mm long sample was fixed on a test bench for a wear test to measure the wear amount (g). The initial weight was T0. After 3000 abrasions, the weight was measured once, T1. After 6000 abrasions, the weight was measured once, T2. After 9000 abrasions, the weight was measured once, T3. After 12000 abrasions, the weight was measured once, T4. The test results are shown in Table 2.

[0072] Table 2 Test results of various embodiments and comparative examples 　 (T1-T0)g (T2-T1)g (T3-T2)g (T4-T3)g Example 1 0.06 0.06 0.06 0.06 Example 2 0.05 0.06 0.06 0.06 Example 3 0.05 0.06 0.06 0.06 Example 4 0.05 0.05 0.05 0.06 Example 5 0.04 0.04 0.05 0.05 Example 6 0.05 0.05 0.05 0.06 Example 7 0.05 0.05 0.06 0.06 Example 8 0.05 0.06 0.06 0.06 Example 9 0.05 0.06 0.06 0.06 Example 10 0.06 0.06 0.06 0.07 Embodiment 11 0.06 0.06 0.06 0.06 Example 12 0.06 0.06 0.06 0.07 Example 13 0.04 0.04 0.04 0.04 Comparative Example 1 0.43 0.46 0.48 0.49 Comparative Example 2 0.2 0.22 0.24 0.26 Comparative Example 3 0.21 0.23 0.25 0.28 Combining Example 2 with Comparative Examples 1 to 3 and Table 2, it can be seen that the compounding of TPU and nitrile powder has a significant effect on improving the wear resistance of the composite material. The two can form an "island structure", a continuous elastic phase, disperse impact stress, absorb impact energy, and reduce wear.

[0073] It can be seen from Example 2 and Example 5 and Table 2 that nano-silicon dioxide as a filler enhances the carrying capacity of the matrix. On this basis, the added carbon nanotubes can form a rigid network structure in the matrix, effectively improving the strength of the composite material. At the same time, this network structure can help stabilize the PEEK powder and prevent them from re-aggregating. The self-lubricating property of PEEK powder can significantly reduce the friction coefficient of the composite material, providing the composite material with higher strength and wear resistance. PEEK powder can also be used as a bridging agent to help disperse carbon nanotubes, help break the agglomeration phenomenon between carbon nanotubes, and promote its uniform distribution in the composite material. Carbon nanotubes can also give the composite material better electrical conductivity and thermal conductivity, transfer heat to the phase change microcapsule PCM to be absorbed, and its own temperature does not change much. PCM microcapsules are added to the composite material, and PCM can be used to absorb excess heat when friction generates heat, and then slowly released when the ambient temperature drops, which helps to reduce the damage of heat to the composite material.

[0074] Combining Example 2, Example 5, Example 7 to Example 12 and Table 2, it can be seen that the best effect is achieved only when the above three substances are used in combination.

[0075] It can be seen from Example 5 and Example 13 and Table 2 that the carbon nanotubes have a better performance improvement effect after being surface modified.

[0076] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make modifications to the present embodiment without any creative contribution as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

Claims

1. A wear-resistant rubber-plastic composite material for high-pressure air pipes, characterized in that: The invention comprises the following raw materials in parts by weight: PVC 100 copies; 36-45 parts of plasticizer; 4-6 parts of stabilizer; 8-13 parts of polytetrafluoroethylene; 3-6 parts of nano silicon dioxide; TPU 22-30 parts; 23-30 parts of nitrile powder; 2 to 4 parts of lubricant.

2. The wear-resistant rubber-plastic composite material for high-pressure air pipe according to claim 1, characterized in that: The rubber-plastic composite material comprises the following raw materials in parts by weight: PVC 100 copies; 40 parts of plasticizer; 5 parts of stabilizer; 10 parts of polytetrafluoroethylene; 5 parts of nano silicon dioxide; TPU 25 parts; 25 parts of nitrile powder; 3 parts of lubricant.

3. The wear-resistant rubber-plastic composite material for high-pressure air pipe according to claim 1, characterized in that: The plasticizer is DOTP.

4. The wear-resistant rubber-plastic composite material for high-pressure air pipe according to claim 1, characterized in that: The stabilizer is a calcium zinc stabilizer.

5. The wear-resistant rubber-plastic composite material for high-pressure air pipe according to claim 1, characterized in that: The lubricant is polyethylene wax.

6. The wear-resistant rubber-plastic composite material for high-pressure air pipe according to claim 1, characterized in that: The rubber-plastic composite material also includes the following raw materials in parts by weight: PEEK micro powder 0.5-1 part; Phase change microcapsule PCM 0.8-1.2 parts; 1 to 1.5 parts of carbon nanotubes.

7. The wear-resistant rubber-plastic composite material for high-pressure air pipe according to claim 6, characterized in that: The carbon nanotubes are surface-modified carbon nanotubes.

8. The method for producing a wear-resistant rubber-plastic composite material for high-pressure air pipes according to any one of claims 1 to 7, characterized in that: The following steps are involved: Take the raw materials according to the ratio, mix them evenly and then extrude them into granules.