A wear-resistant rubber-plastic composite material for high-pressure air pipes and its production method

Abstract

This application relates to the field of polymer materials and specifically discloses a wear-resistant rubber-plastic composite material for high-pressure air pipes and its production method. The composite material comprises the following raw materials in parts by weight: 100 parts PVC; 36-45 parts plasticizer; 4-6 parts stabilizer; 8-13 parts polytetrafluoroethylene; 3-6 parts nanosilica; 22-30 parts TPU; 23-30 parts nitrile powder; and 2-4 parts lubricant. The production method comprises: uniformly mixing the raw materials according to the proportions, followed by extrusion and granulation. The composite material of this application exhibits 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.), and is widely used in industry, automobiles, aerospace, medical equipment and other fields.

[0003] When in use, high-pressure air pipes often need to be dragged, which causes great 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 a first aspect, the present application provides a wear-resistant rubber-plastic composite material for high-pressure air pipes, which adopts the following technical solution:

[0006] A wear-resistant rubber-plastic composite material for high-pressure air pipes, comprising the following raw materials in parts by weight:

[0007] PVC 100 parts;

[0008] 36-45 parts of plasticizer;

[0009] 4-6 parts of stabilizer;

[0010] 8-13 parts of polytetrafluoroethylene;

[0011] 3-6 parts of nano silicon dioxide;

[0012] TPU 22-30 parts;

[0013] 23-30 parts of nitrile powder;

[0014] 2 to 4 parts of lubricant.

[0015] 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, reducing 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 combination of the two can achieve process compatibility.

[0016] Optionally, the rubber-plastic composite material includes the following raw materials in parts by weight:

[0017] PVC 100 parts;

[0018] 40 parts of plasticizer;

[0019] 5 parts of stabilizer;

[0020] 10 parts of polytetrafluoroethylene;

[0021] 5 parts of nano silicon dioxide;

[0022] TPU 25 parts;

[0023] 25 parts of nitrile powder;

[0024] 3 parts lubricant.

[0025] By adopting the above technical solution, the composite material prepared with the above ratio has better wear resistance.

[0026] Optionally, the plasticizer is DOTP.

[0027] Optionally, the stabilizer is a calcium zinc stabilizer.

[0028] Optionally, the lubricant is polyethylene wax.

[0029] Optionally, the rubber-plastic composite material further comprises the following raw materials in parts by weight:

[0030] 0.5-1 part of PEEK micropowder;

[0031] Phase change microcapsules PCM 0.8-1.2 parts;

[0032] 1 to 1.5 parts of carbon nanotubes.

[0033] By adopting this technical solution, the PVC material has a high surface energy, making it prone to adhesion to other substances and, therefore, prone to wear during dragging. The carbon nanotubes impart enhanced electrical and thermal conductivity to the composite material, transferring heat to the PCM microcapsules for absorption without significantly changing their own temperature. Adding PCM microcapsules to the composite material allows the PCM to absorb excess heat generated by friction and slowly release it when the ambient temperature drops, helping to minimize heat damage to the composite material. Furthermore, the PEEK micropowder acts as a bridging agent to help disperse the carbon nanotubes, breaking them up and promoting their uniform distribution within the composite material. Due to their high aspect ratio and surface activity, the carbon nanotubes form a three-dimensional network within the composite matrix. This network helps stabilize the PEEK micropowder and prevents it from reaggregating. The self-lubricating properties of the PEEK micropowder significantly reduce the composite material's coefficient of friction, providing it with enhanced wear resistance.

[0034] Optionally, the carbon nanotubes are surface-modified carbon nanotubes.

[0035] By adopting the above technical solution, the surface-modified carbon nanotubes can enhance the compounding advantages with PEEK micropowder and phase change microcapsules PCM, better disperse in the composite material, form a stable three-dimensional network structure, and improve the wear resistance of the composite material.

[0036] In a second aspect, the present application provides a method for producing a wear-resistant rubber-plastic composite material for high-pressure air pipes, which adopts the following technical solution:

[0037] A method for producing a wear-resistant rubber-plastic composite material for high-pressure air pipes comprises the following steps: mixing raw materials in a proportion, and then extruding and granulating.

[0038] By adopting the above technical solution, the prepared composite material has excellent wear resistance.

[0039] In summary, this application has the following beneficial effects:

[0040] 1. Since this application uses a compound of TPU and nitrile powder, the polar acrylonitrile group of the nitrile powder has good compatibility with PVC and can significantly improve the wear resistance of the PVC material. The high elasticity and wear resistance of TPU further enhance the strength of the PVC material. The combination of TPU and nitrile powder makes the composite material perform better in high-pressure air pipe scenarios.

[0041] 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. When the composite material generates heat through friction, it uses PCM to absorb excess heat, and then slowly releases it when the ambient temperature drops, which helps to reduce the damage to the composite material caused by heat. At the same time, PEEK micropowder can act as a bridging agent to help disperse the carbon nanotubes and promote their uniform distribution in the composite material. Carbon nanotubes can form a three-dimensional network structure in the composite material matrix. This network structure can help stabilize the PEEK micropowder and prevent them from re-aggregating. The effect of improving the wear resistance of the composite material is achieved;

[0042] 3. The composite material prepared by the method of the present application has excellent wear resistance. DETAILED DESCRIPTION

[0043] The present application is further described in detail with reference to the following examples. It is particularly noted that, in the following examples, if no specific conditions are specified, conventional conditions or conditions recommended by the manufacturer are followed, and the raw materials used in the following examples are all commercially available unless otherwise specified.

[0044] PVC, model SG-5, brand Xinjiang Tianye.

[0045] DOTP, dioctyl terephthalate, active ingredient content 99%.

[0046] Calcium zinc stabilizer, liquid compound type, premium grade, brand Rongren Chemical.

[0047] Polytetrafluoroethylene, particle size 10μm.

[0048] Nano-silicon dioxide, 12 mesh.

[0049] TPU, particle size 0.5 mm, BASF 1085A.

[0050] Nitrile powder, 100 mesh, acrylonitrile content 33% to 36%.

[0051] Polyethylene wax, brand Yiteng Chemical, melting point range 90 ~ 116 ℃.

[0052] PEEK micropowder, Victrex L150 (fine powder).

[0053] Phase change microcapsules PCM, industrial grade, particle size 5 μm, temperature 28 °C, were purchased from Hebei Ruosen Technology Co., Ltd.

[0054] Carbon nanotubes (CNTs), brand GTR-300, with an aspect ratio of 800 to 1,000, were purchased from Qingdao Taige New Material Technology Co., Ltd.

[0055] Methacrylic acid (MAA) was purchased from Xi'an Tianmao Chemical Co., Ltd.

[0056] Example of preparation of surface-modified carbon nanotubes.

[0057] Preparation Example 1

[0058] (1) Raw material preparation:

[0059] Carbon nanotubes (CNTs), 1g; white carbon black, 0.5g; methacrylic acid (MAA), 1.5g; zinc oxide (ZnO), 0.5g.

[0060] CNTs pretreatment: CNTs were immersed in a concentrated sulfuric acid / nitric acid mixture (3:1 volume ratio) and treated with ultrasound (40 kHz) at 80°C for 2 hours. After carboxyl modification, they were centrifuged and washed until neutral, and then dried under vacuum at 60°C to obtain acidified CNTs. The acidified CNTs were ultrasonically dispersed in ethanol with a silane coupling agent (KH-570) for 30 minutes, then dried at 80°C for later use. The weight of KH-570 was 0.5% of the weight of the acidified CNTs. The amount of ethanol needed to cover the surface of the CNTs was sufficient.

[0061] (2) Premixing: Acidified CNTs and 40% of the total amount of MAA (0.6 g) were added to a high-speed shear mixer; the temperature was raised to 60 °C and sheared at 1500 rpm for 5 minutes to form a uniform slurry. The slurry viscosity was controlled at 4000 mPa·s (Brookfield viscometer, rotor 3#, 30 rpm).

[0062] (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 2-minute intervals while maintaining the speed at 1500 rpm; after each addition, increase the speed to 2000 rpm and maintain for 1 minute to ensure uniform dispersion.

[0063] (4) In situ reaction and coating: raise the temperature to 85±2°C 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 is bound to the carboxyl groups on the surface of CNTs through ionic bonds to form a dense coating layer).

[0064] (5) Post-treatment: After the reaction, cool to 40 °C and add deionized water to dilute to a solid content of 10%; separate the product by centrifugation (8000 rpm, 15 minutes), wash with ethanol three times to remove unreacted monomers; and vacuum freeze-dry (-50 °C, 24 hours) to avoid cracking of the coating layer caused by high temperature.

[0065] Example

[0066] Example 1

[0067] A wear-resistant rubber-plastic composite material for high-pressure air pipes, comprising the following raw materials:

[0068] PVC; plasticizer: DOTP; stabilizer: calcium zinc stabilizer; polytetrafluoroethylene powder; nano-silica; TPU; nitrile powder; lubricant: polyethylene wax. The amounts of each raw material are detailed in Table 1.

[0069] A method for producing a wear-resistant rubber-plastic composite material for high-pressure air pipes comprises the following steps:

[0070] (1) Raw material pretreatment:

[0071] 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%).

[0072] DOTP: Preheat to 60°C to reduce viscosity and facilitate uniform dispersion.

[0073] 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.

[0074] Polytetrafluoroethylene: Mix and grind with calcium stearate at a ratio of 1% of polytetrafluoroethylene to reduce electrostatic agglomeration.

[0075] (2) High-speed mixing:

[0076] Set the high-speed mixer to 1000 rpm, heat the jacket, and mix the ingredients in the following order: add PVC and heat to 60°C; add calcium zinc stabilizer and DOTP and mix for 3 minutes; add nano-silica, TPU, and nitrile powder and heat to 90°C and mix for 5 minutes; add polytetrafluoroethylene and polyethylene wax and heat to 110°C and mix for 8 minutes. Endpoint control: When the material reaches 110°C and forms a loose mass.

[0077] (3) Cooling and mixing:

[0078] Transfer the high-speed mixed material to a low-temperature cooling mixer, cool it to 45°C, rotate at 800 rpm, and water-cool the jacket for 10 minutes to prevent the hot material from agglomerating.

[0079] (4) Extrusion granulation:

[0080] A twin-screw extruder (L / D = 40:1, screw configuration: high shear zone + multi-stage exhaust) was used. The temperatures were set at: 150°C for zone 1, 165°C for zone 2, 175°C for zone 3, 180°C for zone 4, 175°C for zone 5, and 170°C for the die. The screw speed was 280 ± 20 rpm. The feed rate was matched to the screw speed to ensure a fill factor of 85%. A vacuum of -0.08 MPa was set after zone 2 to remove volatiles. The die pressure was 15 MPa to ensure uniform melt extrusion. After extrusion, the pellets were cooled and cut into 3 x 3 mm diameter pellets at 25°C. They were then dried in a fluidized bed dryer at 50°C for 1 hour to a moisture content of ≤ 0.1%. The pellets were then sieved to remove large particles and debris, and sealed in bags for storage.

[0081] Example 2

[0082] The difference between this embodiment and embodiment 1 is that the amounts of the raw materials used are different, see Table 1 for details.

[0083] Example 3

[0084] The difference between this embodiment and embodiment 1 is that the amounts of the raw materials used are different, see Table 1 for details.

[0085] Example 4

[0086] 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). The usage amounts are shown in Table 1.

[0087] The difference between the production method and Example 2 is:

[0088] (1) Raw material pretreatment:

[0089] PEEK micropowder needs to be vacuum dried at 150℃ for 3 hours before adding to prevent hydrolysis during high temperature processing.

[0090] (2) High-speed mixing:

[0091] Addition order: add PVC, calcium zinc stabilizer, and DOTP, and mix at 60°C for 3 minutes; add TPU, nitrile powder, and nano-silica, and mix at 90°C for 5 minutes; cool to 70°C, add polytetrafluoroethylene and PEEK powder, and mix at 1200 rpm for 3 minutes; add carbon nanotubes and high-speed shear at 2000 rpm for 5 minutes; cool to 50°C, add phase change microcapsules PCM and polyethylene wax, and mix at low speed at 800 rpm for 2 minutes.

[0092] (3) Cooling and mixing:

[0093] Cool the mixer down to 35°C.

[0094] (4) Extrusion granulation:

[0095] A twin-screw extruder (L / D = 44:1, screw combination: high shear + slow-release zone) was used. The temperatures were set at: 145°C in zone 1, 160°C in zone 2, 170°C in zone 3, 175°C in zone 4, 170°C in zone 5, and 165°C at the die. The screw speed was 240 ± 20 rpm. The feed rate was matched to the screw speed to ensure an 85% fill rate. A two-stage vacuum (-0.08 MPa to -0.09 MPa) was set in zone 3 to remove volatiles. The die pressure was 12 MPa to ensure uniform melt extrusion. After extrusion, the pellets were cooled and cut into 3 x 3 mm diameter pellets at 20°C. They were then dried in a fluidized bed dryer at 40°C for 1 hour to a moisture content of ≤ 0.1%. The pellets were then sieved to remove large particles and debris, and sealed in bags for storage.

[0096] Example 5

[0097] The difference between this embodiment and embodiment 4 is that the amounts of the raw materials are different, see Table 1 for details.

[0098] Example 6

[0099] The difference between this embodiment and embodiment 4 is that the amounts of the raw materials are different, see Table 1 for details.

[0100] Example 7

[0101] The difference between this embodiment and embodiment 5 is that there is no PEEK powder in this embodiment.

[0102] Example 8

[0103] The difference between this embodiment and embodiment 5 is that this embodiment does not include phase change microcapsules PCM.

[0104] Example 9

[0105] The difference between this embodiment and embodiment 5 is that there are no carbon nanotubes in this embodiment.

[0106] Example 10

[0107] The difference between this embodiment and embodiment 5 is that this embodiment does not contain PEEK powder and phase change microcapsules PCM.

[0108] Example 11

[0109] The difference between this embodiment and embodiment 5 is that this embodiment does not contain PEEK powder and carbon nanotubes.

[0110] Example 12

[0111] The difference between this embodiment and embodiment 5 is that this embodiment does not include phase change microcapsules PCM and carbon nanotubes.

[0112] Example 13

[0113] 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.

[0114] Comparative Example.

[0115] Comparative Example 1

[0116] 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.

[0117] Comparative Example 2

[0118] The difference between this comparative example and Example 2 is that the raw materials of this comparative example do not contain TPU.

[0119] Comparative Example 3

[0120] The difference between this comparative example and Example 2 is that there is no butyronitrile powder in the raw materials of this comparative example.

[0121] Table 1 Amounts of raw materials used in various examples and comparative examples

[0122] PVC / g DOTP / g Calcium zinc stabilizer / g Polytetrafluoroethylene / g Nanosilica / g TPU / g Nitrile powder / g Polyethylene wax / g PEEK powder / g Phase change microcapsules 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 Example 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

[0123] Performance detection test.

[0124] Detection method.

[0125] 1. Abrasion Resistance: The particles obtained from the above examples and comparative examples were extruded into sheaths for high-pressure air pipes with a diameter of 12.0 mm. Linear abrasion was performed using a Taber 5750 linear abrader with a 15×15 mm die, P600 sandpaper applied to the abrasion surface, a load of 350 g, a cycle rate of 50 cycles / min, and a stroke of 100 mm. A 200 mm long specimen was fixed to the test bench for abrasion testing, and the wear loss (g) was measured. The initial weight was T0. After 3000 abrasion cycles, the weight was measured as T1. After 6000 abrasion cycles, the weight was measured as T2. After 9000 abrasion cycles, the weight was measured as T3. After 12,000 abrasion cycles, the weight was measured as T4. The test results are shown in Table 2.

[0126] Table 2 Test results of various embodiments and comparative examples

[0127] (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 Example 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

[0128] Combining Example 2 with Comparative Examples 1 to 3 and Table 2 shows that the combined addition of TPU and nitrile powder significantly improves the wear resistance of the composite material. The two can form an "island structure," creating a continuous elastic phase that disperses impact stress, absorbs impact energy, and reduces wear.

[0129] It can be seen from Example 2 and Example 5 and Table 2 that nano-silica as a filler enhances the bearing 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 micropowder and prevent them from re-aggregating. The self-lubricating property of PEEK micropowder can significantly reduce the friction coefficient of the composite material, providing the composite material with higher strength and wear resistance. PEEK micropowder can also serve as a bridging agent to help disperse the carbon nanotubes, helping to break the agglomeration phenomenon between the carbon nanotubes and promote their uniform distribution in the composite material. Carbon nanotubes can also give the composite material better electrical and thermal conductivity, transferring heat to the phase change microcapsules PCM to be absorbed, and their own temperature does not change much. When PCM microcapsules are added to the composite material, the PCM can be used to absorb excess heat when friction generates heat, and then slowly release it when the ambient temperature drops, which helps to reduce the damage to the composite material caused by heat.

[0130] 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.

[0131] Combining Example 5 and Example 13 with Table 2, it can be seen that the carbon nanotubes have a better performance improvement effect only after being surface modified.

[0132] 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 non-creative modifications to the present embodiment as needed, but as long as they are within the scope of the claims of the present application, they are protected by the patent law.

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 parts; 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; 2-4 parts of lubricant; 0.5-1 part of PEEK micropowder; Phase change microcapsule PCM 0.8-1.2 parts, purchased from Hebei Ruosen Technology Co., Ltd.; 1 to 1.5 parts of carbon nanotubes.

2. The wear-resistant rubber-plastic composite material for high-pressure air pipes according to claim 1, characterized in that: The rubber-plastic composite material comprises the following raw materials in parts by weight: PVC 100 parts; 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 lubricant.

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

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

6. The wear-resistant rubber-plastic composite material for high-pressure air pipes according to claim 1, characterized in that: The carbon nanotubes are surface-modified carbon nanotubes.

7. The method for producing a wear-resistant rubber-plastic composite material for high-pressure air pipes according to any one of claims 1 to 6, characterized in that: The following steps are involved: Mix the raw materials evenly according to the ratio and then extrude and granulate.