High-performance carbon fiber reinforced coating material and mining cable

Abstract

The invention relates to the technical field of polymer composite materials, in particular to a high-performance carbon fiber reinforced coating material and a mining cable, and the high-performance carbon fiber reinforced coating material is prepared through the following preparation steps: S1, short carbon fiber pretreatment; s2, dispersing the silicon carbide nanowires; s3, performing dry mixing on the premix; s4, plasma synergistic activation; s5, performing two-section type melt extrusion; and S6, gradient compression molding. According to the invention, a polyphase composite system which takes the polyether-ether-ketone resin as a matrix and is synergistically enhanced by the short carbon fibers and the silicon carbide nanowires is constructed, so that the mechanical strength, the thermal stability and the fatigue resistance of the material are remarkably improved; the short carbon fibers are subjected to acid oxidation and coupling agent surface modification, so that the interface bonding force between a reinforced phase and the resin is effectively enhanced; by adopting plasma activation treatment and magnetic field assisted orientation technologies, a phosphorus-nitrogen flame retardant and polyimide micro powder are cooperatively introduced, so that multiple improvements of flame retardance, electrical insulation and heat resistance are further realized.

Description

Technical Field

[0001] This invention relates to the field of polymer composite materials technology, and in particular to a high-performance carbon fiber reinforced coating material and a mining cable. Background Technology

[0002] In mining cables, aviation cables, and high-performance electrical connection devices, the sheathing material not only needs to have excellent mechanical strength and high temperature resistance, but also good flame retardancy, dielectric stability, and long-term service reliability.

[0003] Traditional coating materials are mostly based on polyolefins, polyvinyl chloride, or general-purpose thermoplastic resins. Although they have good processability, their performance is prone to degradation under high temperature, high pressure, and corrosive environments. Especially when used in coal mines or near high-heat equipment, their mechanical structure is easily damaged, and their flame-retardant properties decrease, making it difficult to meet the long-term high safety requirements of applications. With increasingly complex application environments, there is an urgent need for a high-performance carbon fiber reinforced coating material and mining cables to solve this problem. Summary of the Invention

[0004] To achieve the above objectives, the present invention provides a high-performance carbon fiber reinforced coating material and a mining cable.

[0005] A high-performance carbon fiber reinforced coating material includes polyetheretherketone resin, chopped carbon fibers, silicon carbide nanowires, polyimide micropowder, epoxy resin, aminosilane coupling agent, and phosphorus-nitrogen synergistic flame retardant; the specific preparation of this coating material includes the following steps:

[0006] S1, Pretreatment of chopped carbon fibers: After being oxidized by acid solution, chopped carbon fibers are ultrasonically impregnated with aminosilane coupling agent solution and then dried.

[0007] S2, Silicon carbide nanowire dispersion: Silicon carbide nanowires and epoxy resin are circulated and ground using a three-roll mill to form a homogeneous dispersion slurry;

[0008] S3, Dry Premix: Polyetheretherketone resin, polyimide micro powder, phosphorus-nitrogen synergistic flame retardant, aminosilane coupling agent and nano-dispersion slurry obtained in S2 are mixed at high temperature and high speed to form a premix.

[0009] S4, Plasma-assisted activation: The premix of S3 is subjected to plasma surface activation treatment in a mixed atmosphere of inert gas and oxygen.

[0010] S5, two-stage melt extrusion: First, the premixed material activated by S4 is melt extruded in one stage, and then short-cut carbon fibers treated by S1 are injected and a magnetic field is applied to complete the second stage extrusion to obtain extruded granules;

[0011] S6, gradient molding: The S5 extruded granules are subjected to three stages of molding: heating and pressing, high temperature and high pressure preservation, and gradient cooling, and finally demolded to obtain the finished coating material.

[0012] Optionally, the components of the coating material are as follows by weight percentage: 22-58.5% polyetheretherketone resin, 25-40% chopped carbon fiber, 3-8% silicon carbide nanowires, 5-10% polyimide micropowder, 3-6% epoxy resin, 0.5-2% aminosilane coupling agent, and 5-12% phosphorus-nitrogen synergistic flame retardant.

[0013] Optionally, the chopped carbon fiber has a length of 200-500 μm and a single filament diameter of 7 μm; the phosphorus-nitrogen synergistic flame retardant is composed of ammonium polyphosphate and melamine cyanurate in a mass ratio of 2:1; the aminosilane coupling agent is a compound of γ-aminopropyltriethoxysilane and γ-propyltrimethoxysilane in a mass ratio of 3:1.

[0014] Optionally, S1 specifically includes:

[0015] S11, acid solution oxidation treatment: immerse short-cut carbon fibers in nitric acid solution and treat at a constant temperature of 70-90℃ for 0.5-2 hours;

[0016] S12, Washing and Drying: Wash the treated short-cut carbon fibers with deionized water until neutral, and dry them at 100-120℃ for 1-3 hours;

[0017] S13, Coupling agent impregnation: The dried short-cut carbon fibers are placed in an ethanol solution containing an aminosilane coupling agent, wherein the mass fraction of the aminosilane coupling agent in the ethanol solution is 3-8%, and ultrasonically treated at 40-60℃ for 20-40 minutes.

[0018] S14, Post-treatment drying: The impregnated short-cut carbon fibers are vacuum filtered and dried at 105-125℃ for 1-2 hours.

[0019] Optionally, S2 specifically includes:

[0020] S21, Initial mixing: Add silicon carbide nanowires and epoxy resin to a mixing tank at a predetermined mass ratio, and stir at a speed of 200-400 r / min for 10-20 minutes.

[0021] S22, initial grinding: Transfer the S21 mixture to a three-roll mill and perform the first grinding under the conditions of a roll gap of 0.05-0.15mm and a roll temperature of 50-70℃;

[0022] S23, Circulating Fine Grinding: Adjust the roller gap to 0.02-0.08mm, and circulate and grind the material 3-7 times at the same roller temperature;

[0023] S24, Endpoint determination: When the rotational viscosity of the slurry reaches 5000-8000 mPa·s at 25℃, stop grinding to obtain a homogeneous dispersion slurry.

[0024] Optionally, S3 specifically includes:

[0025] S31, Main Resin Premixing: Add polyetheretherketone resin and polyimide micro powder to a high-speed mixer at a predetermined mass ratio, and mix for 5-10 minutes at 100-130℃ and 500-800r / min.

[0026] S32, Flame retardant addition: Add phosphorus and nitrogen synergistic flame retardant to the S31 mixture, maintain the temperature, and increase the rotation speed to 800-1200 r / min to mix for 3-8 minutes;

[0027] S33, Nano slurry blending: The silicon carbide nanowire dispersion slurry obtained in S2 is added simultaneously with the aminosilane coupling agent and mixed for 10-20 minutes at 120-140℃ and 1000-1500r / min.

[0028] S34, when the material is in a uniform flow state, stop mixing, discharge and cool to room temperature to obtain premixed material.

[0029] Optionally, S4 specifically includes:

[0030] S41, Loading and Temperature Control: Spread the premixed material obtained in S3 evenly on a quartz tray, controlling the material layer thickness to 2-5mm. After transferring it into the plasma treatment chamber, pre-evacuate to 10⁻²P. a ;

[0031] S42, Atmosphere replacement: Introduce a mixture of argon and oxygen into the cavity, with oxygen accounting for 10-30% of the volume, and maintain the working pressure at 50-200 Pa.

[0032] S43, Plasma Activation: Apply radio frequency power with an electrode spacing of 50-80 mm to achieve a power density of 0.5-1.5 W / cm². 2 Processing time: 2-8 minutes;

[0033] S44, Inertization discharge: After turning off the RF power supply, continuously introduce argon gas for 5-10 minutes, and remove the activated premix when the material temperature drops below 60℃.

[0034] Optionally, S5 specifically includes:

[0035] S51, Extrusion preparation: Add the activated premix obtained in S4 to the main feed port of the twin-screw extruder, and set the temperatures of the extruder zone IV to 320-340℃, 330-350℃, 340-360℃, 350-370℃, and 360-380℃ respectively.

[0036] S52, First stage of melt plasticizing: Melt blending is carried out at a screw speed of 100-180 r / min, the melt pressure is maintained at 8-15 MPa, and the residence time is 1-3 minutes;

[0037] S53, two-stage fiber injection: S1 pretreated short-cut carbon fibers are injected into the feed port of the fourth zone of the extruder. The addition rate is controlled by a loss-in-weight feeder to be 30-50% of the main feed amount. An axial magnetic field with a strength of 0.3-0.8T is applied simultaneously.

[0038] S54, two-stage extrusion granulation: fiber directional dispersion is completed at a temperature of 360-380℃ in zone V and a screw speed of 150-220r / min, and the material is cut into cylindrical particles with a length of 2-4mm and a diameter of 1.5-2.5mm by a water-cooled pelletizer.

[0039] Optionally, S6 specifically includes:

[0040] S61, Preheating of material loading: The extruded granules obtained in S5 are evenly filled into the mold cavity, and heated to 390℃ at a rate of 3-5℃ / min under a pressure of 10-15MPa.

[0041] S62, First-stage pressure molding: Maintain a temperature of 390℃, apply pressure to 20-25MPa and hold pressure for 15-25 minutes;

[0042] S63, Level 2 High Temperature Curing: Continue heating to 410℃, pressurize to 30-35MPa and hold for 25-35 minutes;

[0043] S64, Gradient cooling demolding: Cool to 200℃ at a rate of 1-3℃ / min, release the pressure, open the mold and take out the blank;

[0044] S65, Finished product shaping: The blank is placed in a heat treatment furnace and heated to 230℃ at a rate of 2-4℃ / min and held at that temperature for 1.5-2.5 hours. Finally, it is cooled to room temperature with the furnace to obtain the finished carbon fiber reinforced coating material.

[0045] A mining cable using the aforementioned high-performance carbon fiber reinforced sheathing material.

[0046] The beneficial effects of this invention are:

[0047] This invention significantly improves the mechanical strength, thermal stability, and fatigue resistance of a multiphase composite system with polyetheretherketone resin as the matrix and synergistic reinforcement of chopped carbon fibers and silicon carbide nanowires. By subjecting the chopped carbon fibers to acid oxidation and surface modification with coupling agents, the interfacial bonding between the reinforcing phase and the resin is effectively enhanced, avoiding the interfacial debonding problem common in traditional reinforcing materials.

[0048] This invention improves the dispersion uniformity and fiber orientation of the composite material by employing plasma activation treatment and magnetic field-assisted orientation technology. It also synergistically introduces phosphorus-nitrogen flame retardants and polyimide micro powder, further enhancing the flame retardant performance, electrical insulation, and heat resistance. Attached Figure Description

[0049] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only for this invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0050] Figure 1 This is a schematic diagram of the preparation method of the coating material according to an embodiment of the present invention. Detailed Implementation

[0051] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. It should also be noted that, to make the embodiments more comprehensive, the following embodiments are the best and preferred embodiments, and those skilled in the art can use other alternative methods to implement some well-known technologies; moreover, the accompanying drawings are only for more specific description of the embodiments and are not intended to specifically limit the present invention.

[0052] It should be noted that the use of terms such as "an embodiment," "an embodiment," "an exemplary embodiment," and "some embodiments" in the specification indicates that the described embodiment may include a specific feature, structure, or characteristic, but not every embodiment necessarily includes that specific feature, structure, or characteristic. Furthermore, when a specific feature, structure, or characteristic is described in connection with an embodiment, implementing such a feature, structure, or characteristic in conjunction with other embodiments (whether explicitly described or not) should be within the knowledge of those skilled in the art.

[0053] Generally, terms can be understood at least partly from their use in context. For example, depending at least partly on the context, the term "one or more" as used herein can be used to describe any feature, structure, or characteristic in a singular sense, or a combination of features, structures, or characteristics in a plural sense. Additionally, the term "based on" can be understood not necessarily to convey an exclusive set of factors, but rather, alternatively, depending at least partly on the context, to allow for the presence of other factors that are not necessarily explicitly described.

[0054] Example 1

[0055] like Figure 1As shown, a high-performance carbon fiber reinforced coating material includes polyetheretherketone resin, chopped carbon fibers, silicon carbide nanowires, polyimide micropowder, epoxy resin, aminosilane coupling agent, and phosphorus-nitrogen synergistic flame retardant; the specific preparation of this coating material includes the following steps:

[0056] S1, Pretreatment of chopped carbon fibers: After being oxidized by acid solution, chopped carbon fibers are ultrasonically impregnated with aminosilane coupling agent solution and then dried.

[0057] S2, Silicon carbide nanowire dispersion: Silicon carbide nanowires and epoxy resin are circulated and ground using a three-roll mill to form a homogeneous dispersion slurry;

[0058] S3, Dry Premix: Polyetheretherketone resin, polyimide micro powder, phosphorus-nitrogen synergistic flame retardant, aminosilane coupling agent and nano-dispersion slurry obtained in S2 are mixed at high temperature and high speed to form a premix.

[0059] S4, Plasma-assisted activation: The premix of S3 is subjected to plasma surface activation treatment in a mixed atmosphere of inert gas and oxygen.

[0060] S5, two-stage melt extrusion: First, the premixed material activated by S4 is melt extruded in one stage, and then short-cut carbon fibers treated by S1 are injected and a magnetic field is applied to complete the second stage extrusion to obtain extruded granules;

[0061] S6, gradient molding: The S5 extruded granules are subjected to three stages of molding: heating and pressing, high temperature and high pressure preservation, and gradient cooling, and finally demolded to obtain the finished coating material.

[0062] The components of the coating material, by weight percentage, are: 46% polyetheretherketone resin, 30% chopped carbon fiber, 5% silicon carbide nanowires, 6% polyimide micropowder, 4% epoxy resin, 1% aminosilane coupling agent, and 8% phosphorus-nitrogen synergistic flame retardant.

[0063] The chopped carbon fiber has a length of 200-500μm and a single filament diameter of 7μm; the phosphorus-nitrogen synergistic flame retardant is composed of ammonium polyphosphate and melamine cyanurate in a mass ratio of 2:1; the aminosilane coupling agent is a compound of γ-aminopropyltriethoxysilane and γ-propyltrimethoxysilane in a mass ratio of 3:1.

[0064] S1 specifically includes:

[0065] S11, acid solution oxidation treatment: short-cut carbon fibers are immersed in nitric acid solution and treated at 80°C for 1 hour;

[0066] S12, Washing and Drying: The treated short-cut carbon fibers are washed with deionized water until neutral and dried at 110°C for 2 hours.

[0067] S13, Coupling agent impregnation: The dried short-cut carbon fibers are placed in an ethanol solution containing an aminosilane coupling agent, the mass fraction of which is 5%, and ultrasonically treated at 50°C for 30 minutes.

[0068] S14, Post-treatment drying: The impregnated short-cut carbon fibers are vacuum filtered and dried at 110°C for 1.5 hours.

[0069] S2 specifically includes:

[0070] S21, Initial mixing: Add silicon carbide nanowires and epoxy resin to a mixing tank at a predetermined mass ratio, and stir at 300 r / min for 15 minutes;

[0071] S22, initial grinding: The S21 mixture is transferred to a three-roll mill and ground for the first time at a roller gap of 0.10 mm and a roller temperature of 60°C.

[0072] S23, Circulating fine grinding: Adjust the roller gap to 0.05mm and circulate and grind the material 5 times at the same roller temperature;

[0073] S24, Endpoint determination: When the rotational viscosity of the slurry reaches 6000 mPa·s at 25℃, stop grinding to obtain a homogeneous dispersion slurry.

[0074] S3 specifically includes:

[0075] S31, Main Resin Premixing: Add polyetheretherketone resin and polyimide micro powder to a high-speed mixer at a predetermined mass ratio and mix for 7 minutes at 120℃ and 600r / min.

[0076] S32, Flame retardant addition: Add phosphorus-nitrogen synergistic flame retardant to the S31 mixture, maintain the temperature, and increase the rotation speed to 1000 r / min to mix for 5 minutes;

[0077] S33, Nanoparticle slurry blending: The silicon carbide nanowire dispersion slurry obtained in S2 is added simultaneously with the aminosilane coupling agent and mixed for 15 minutes at 130℃ and 1200r / min.

[0078] S34, when the material is in a uniform flow state, stop mixing, discharge and cool to room temperature to obtain premixed material.

[0079] S4 specifically includes:

[0080] S41, Loading and Temperature Control: Spread the premixed material obtained in S3 evenly on a quartz tray, controlling the material layer thickness to 3mm. After transferring it into the plasma treatment chamber, pre-evacuate to 10⁻²P. a ;

[0081] S42, Atmosphere replacement: Introduce a mixture of argon and oxygen into the cavity, with oxygen accounting for 20% of the volume, and maintain the working pressure at 100 Pa.

[0082] S43, Plasma Activation: RF power is applied with an electrode spacing of 60 mm to achieve a power density of 1.0 W / cm². 2 Processing time: 5 minutes;

[0083] S44, Inertization discharge: After turning off the RF power supply, continuously introduce argon gas for 8 minutes, and remove the activated premix when the material temperature drops to 55℃.

[0084] S5 specifically includes:

[0085] S51, Extrusion preparation: Add the activated premix obtained in S4 to the main feed port of the twin-screw extruder, and set the temperatures of the extruder zone IV to 330℃, 340℃, 350℃, 360℃, and 370℃ respectively.

[0086] S52, First stage of melt plasticization: Melt blending is carried out at a screw speed of 140 r / min, the melt pressure is maintained at 12 MPa, and the residence time is 2 minutes;

[0087] S53, two-stage fiber injection: S1 pretreated short-cut carbon fibers are injected into the feed port of the fourth zone of the extruder. The addition rate is controlled by a loss-in-weight feeder to be 40% of the main feed amount. An axial magnetic field with a magnetic field strength of 0.5T is applied simultaneously.

[0088] S54, two-stage extrusion granulation: fiber directional dispersion is completed at a temperature of 370℃ in zone V and a screw speed of 200r / min, and the material is cut into cylindrical particles with a length of 3mm and a diameter of 2mm by a water-cooled pelletizer.

[0089] S6 specifically includes:

[0090] S61, Preheating of material loading: The extruded granules obtained in S5 are uniformly filled into the mold cavity and heated to 390℃ at a rate of 4℃ / min under a pressure of 13MPa.

[0091] S62, Level 1 Pressure Holding Molding: Maintain a temperature of 390℃, apply pressure to 23MPa and hold pressure for 20 minutes;

[0092] S63, Level 2 High Temperature Curing: Continue heating to 410℃, pressurize to 32MPa and hold for 30 minutes;

[0093] S64, Gradient cooling demolding: Cool to 200℃ at a rate of 2℃ / min, release the pressure, open the mold and take out the blank;

[0094] S65, Finished product shaping: The blank is placed in a heat treatment furnace and heated to 230°C at a rate of 3°C / min and kept at that temperature for 2 hours. Finally, it is cooled to room temperature with the furnace to obtain the finished carbon fiber reinforced coating material.

[0095] Example 2

[0096] Formulation composition: 58.5% polyetheretherketone resin, 25% short-cut carbon fiber (200μm in length), 3% silicon carbide nanowires, 5% polyimide micro powder, 3% epoxy resin, 0.5% aminosilane coupling agent, and 5% phosphorus-nitrogen synergistic flame retardant.

[0097] The preparation steps are as follows:

[0098] S1: Short carbon fibers with a length of 200 μm and a single filament diameter of 7 μm were immersed in a nitric acid solution at 70 °C for 0.5 hours, washed with deionized water until neutral, and dried at 100 °C for 1 hour; then placed in an ethanol solution with a mass fraction of 3% aminosilane coupling agent, ultrasonically treated at 40 °C for 20 minutes, vacuum filtered, and dried at 105 °C for 1 hour to complete the surface coupling modification;

[0099] S2: Add silicon carbide nanowires and epoxy resin to a mixing tank and premix them at 200 r / min for 10 minutes. Then transfer them to a three-roll mill. The initial grinding gap is set to 0.05 mm and the roller temperature is 50 ℃. After the basic grinding is completed, adjust the roller gap to 0.02 mm and keep the roller temperature constant. Grind three times in a cycle. The rotational viscosity reaches 5000 mPa·s at 25 ℃ to obtain a homogeneous dispersion slurry.

[0100] S3: Add polyetheretherketone resin and polyimide micro powder to a high-speed mixer and mix for 5 minutes at 100℃ and 500r / min. Then add phosphorus and nitrogen synergistic flame retardant and continue mixing for 3 minutes at a constant temperature and increased speed to 800r / min. Subsequently, add the nano slurry obtained in S2 and aminosilane coupling agent and continue mixing for 10 minutes at 120℃ and 1000r / min. Finally, when the material has a uniform flow state, discharge and cool to room temperature to obtain the premix.

[0101] S4: Spread the premix obtained in S3 evenly in a quartz tray, controlling the thickness of the material layer to 2mm, and place it in the plasma treatment chamber to evacuate to 10⁻²P. a An argon-oxygen mixture with an oxygen volume ratio of 10% was introduced into the cavity to maintain an internal pressure of 50 Pa; the electrode spacing was set to 50 mm, and a radio frequency power density of 0.5 W / cm² was applied. 2 Processing time is 2 minutes; after turning off the power, argon gas is continuously introduced for 5 minutes to inertize and cool down, and the material is taken out after the temperature is below 50℃.

[0102] S5: The activated premixed material is added to the main feed port of the twin-screw extruder. The temperatures of zones I to V are set to 320℃, 330℃, 340℃, 350℃ and 360℃ respectively. The screw speed is set to 100r / min, the melt pressure is controlled at 8MPa, and the material residence time is 1 minute to complete the first stage of plasticization. Short-cut carbon fibers treated in S1 are injected into the side feed port of zone 4 at an injection rate of 30% of the main feed amount. A 0.3T axial magnetic field is applied simultaneously. Finally, the fiber directional mixing is completed at a temperature of 360℃ in zone V and a speed of 150r / min. The cylindrical pellets with a particle size of 2mm and a length of 1.5mm are obtained through a water-cooled pelletizing mechanism.

[0103] S6: The extruded granules are evenly filled into the mold cavity. Under the condition of initial pressure of 10MPa, the temperature is increased to 390℃ at a rate of 3℃ / min, and then the pressure is increased to 20MPa and held for 15 minutes to form the first stage of plasticity. The temperature is further increased to 410℃ and the pressure is increased to 30MPa. The pressure is held for 25 minutes to complete the high-temperature curing. Then the temperature is decreased to 200℃ at a rate of 1℃ / min, the pressure is released, the mold is opened, and the blank is removed. It is placed in a heat treatment furnace and heated to 230℃ at a rate of 2℃ / min. The temperature is kept constant for 1.5 hours, and finally cooled to room temperature with the furnace to obtain the final product.

[0104] Example 3

[0105] Formulation composition: 22% polyetheretherketone resin, 40% short-cut carbon fiber (500μm in length), 8% silicon carbide nanowires, 10% polyimide micro powder, 6% epoxy resin, 2% aminosilane coupling agent, and 12% phosphorus-nitrogen synergistic flame retardant.

[0106] The preparation steps are as follows:

[0107] S1: Short carbon fibers with a length of 500 μm and a single filament diameter of 7 μm were immersed in a nitric acid solution at 90 °C for 2 hours, washed with deionized water until neutral, and dried at 120 °C for 3 hours. Subsequently, they were placed in an ethanol solution with an 8% (w / w) aminosilane coupling agent and ultrasonically treated at 60 °C for 40 minutes. After vacuum filtration, they were dried at 125 °C for 2 hours to complete the surface coupling modification.

[0108] S2: Add silicon carbide nanowires and epoxy resin to a mixing tank and premix at 400 r / min for 20 minutes; then transfer to a three-roll mill. The initial grinding gap is set to 0.15 mm and the roller temperature is 70℃. After the basic grinding is completed, adjust the roller gap to 0.08 mm and keep the roller temperature constant. Cycle grinding is performed 7 times. The rotational viscosity reaches 8000 mPa·s at 25℃ to obtain a homogeneous dispersion slurry.

[0109] S3: Add polyetheretherketone resin and polyimide micro powder to a high-speed mixer and mix for 10 minutes at 130°C and 800 r / min. Then add phosphorus and nitrogen synergistic flame retardant and continue mixing for 8 minutes at a constant temperature and increased speed to 1200 r / min. Subsequently, add the nano slurry obtained in S2 and aminosilane coupling agent and continue mixing for 20 minutes at 140°C and 1500 r / min. Finally, discharge the material when it has a uniform flow state and cool it to room temperature to obtain the premix.

[0110] S4: Spread the premix obtained in S3 evenly in a quartz tray, controlling the thickness of the material layer to 5mm, and place it in the plasma treatment chamber to evacuate to 10⁻²P. a An argon-oxygen mixture with an oxygen volume ratio of 30% was introduced into the cavity to maintain an internal pressure of 200 Pa; the electrode spacing was set to 80 mm, and a radio frequency power density of 1.5 W / cm² was applied. 2 The processing time is 8 minutes; after turning off the power, argon gas is continuously introduced for 10 minutes to inertize and cool the material. The material is taken out after the temperature is below 40°C.

[0111] S5: The activated premix is ​​added to the main feed port of the twin-screw extruder. The temperatures of zones I to V are set to 340℃, 350℃, 360℃, 30℃ and 380℃ respectively. The screw speed is set to 180 r / min, the melt pressure is controlled at 15 MPa, and the material residence time is 3 minutes to complete the first stage of plasticization. Short-cut carbon fibers treated in S1 are injected into the side feed port of zone 4 at an injection rate of 50% of the main feed amount. A 0.8T axial magnetic field is applied simultaneously. Finally, the fiber directional mixing is completed at a temperature of 380℃ in zone V and a speed of 220 r / min. The cylindrical pellets with a particle size of 4 mm and a length of 2.5 mm are obtained through a water-cooled pelletizing mechanism.

[0112] S6: The extruded granules are evenly filled into the mold cavity. Under the condition of initial pressure of 15MPa, the temperature is increased to 390℃ at a rate of 5℃ / min, and then the pressure is increased to 25MPa and held for 25 minutes to form the first stage of plasticity. The temperature is further increased to 410℃ and the pressure is increased to 35MPa. The pressure is held for 35 minutes to complete the high-temperature curing. Then the temperature is decreased to 200℃ at a rate of 3℃ / min, the pressure is released, the mold is opened, and the blank is removed. It is placed in a heat treatment furnace and heated to 230℃ at a rate of 4℃ / min. The temperature is kept constant for 2.5 hours, and finally cooled to room temperature with the furnace to obtain the final product.

[0113] Comparative Example 1: Conventional Coating Material Preparation Method

[0114] Formulation composition: 60% polypropylene matrix resin, 35% short-cut carbon fiber (300μm in length), 1% coupling agent, and 4% halogen-free flame retardant.

[0115] The preparation steps are as follows:

[0116] S1: Short carbon fibers are mixed with a 2% (w / w) coupling agent ethanol solution, left to stand at room temperature for 30 minutes, and then dried at 100°C for 2 hours to enhance the interfacial bonding with the resin.

[0117] S2: Add the dried carbon fiber, polypropylene, and flame retardant to a twin-screw extruder according to the specified ratio. Set the heating zone temperature to 180℃, 200℃, 220℃, and 230℃, and the screw speed to 100r / min. After melt blending, the material is discharged and cut into cylindrical particles with a diameter of 2mm.

[0118] S3: The obtained mixed particles are filled into a mold, and hot-pressed at 230℃ and 15MPa for 10 minutes, then cooled and demolded to obtain a carbon fiber reinforced coating material sample.

[0119] Table 1 Performance Parameters and Comparison of Coating Materials

[0120]

[0121] As shown in Table 1 above, Example 1 exhibits the strongest tensile strength (210 MPa) and flexural modulus (12.5 GPa), significantly outperforming other schemes. This is mainly due to the combined effects of plasma activation, nano-dispersion, and magnetic field-induced fiber orientation. Regarding notched impact strength, Example 1 reaches 28.6 kJ / m. 2 It is superior to Examples 2 and 3, and far exceeds the 12.1 kJ / m² of the comparative example. 2 Example 1 has a heat distortion temperature of 240℃, demonstrating the synergistic advantages of polyetheretherketone resin and high-efficiency structural uniformity; Example 1 has a volume resistivity of 1.2 × 10⁻⁶. 6 The Ω·cm indicates that the carbon fiber and the matrix interface are more tightly bonded, effectively preventing charge migration. Thanks to the phosphorus-nitrogen synergistic flame retardant system and uniform dispersion, the LOI of Example 1 is 39.2%, which is more than 10% higher than that of the comparative example. The water absorption rate of Example 1 is only 0.18%, which is much lower than that of the comparative material (0.72%), showing that its interface encapsulation effect is good.

[0122] In summary, Example 1, through multi-level structural control and synergistic optimization of functional components, achieved excellent mechanical strength, thermal stability, electrical insulation, and flame retardant protection performance, demonstrating the best performance in all evaluation indicators and possessing significant advantages for engineering applications.

[0123] This invention encompasses any substitutions, modifications, equivalent methods, and solutions made within the spirit and scope of this invention. To provide the public with a thorough understanding of this invention, specific details are described in detail in the following preferred embodiments; however, those skilled in the art will fully understand the invention even without these details. Furthermore, to avoid unnecessary misunderstanding of the essence of this invention, well-known methods, processes, procedures, components, and circuits are not described in detail.

[0124] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A high-performance carbon fiber reinforced coating material, characterized in that, The coating material comprises polyetheretherketone resin, chopped carbon fibers, silicon carbide nanowires, polyimide micropowder, epoxy resin, aminosilane coupling agent, and phosphorus-nitrogen synergistic flame retardant; the specific preparation of this coating material includes the following steps: S1, Pretreatment of chopped carbon fibers: After being oxidized by acid solution, chopped carbon fibers are ultrasonically impregnated with aminosilane coupling agent solution and then dried. S2, Silicon carbide nanowire dispersion: Silicon carbide nanowires and epoxy resin are circulated and ground using a three-roll mill to form a homogeneous dispersion slurry; S3, Dry Premix: Polyetheretherketone resin, polyimide micro powder, phosphorus-nitrogen synergistic flame retardant, aminosilane coupling agent and nano-dispersion slurry obtained in S2 are mixed at high temperature and high speed to form a premix. S4, Plasma-assisted activation: The premix of S3 is subjected to plasma surface activation treatment in a mixed atmosphere of inert gas and oxygen. S5, two-stage melt extrusion: First, the premixed material activated by S4 is melt extruded in one stage, and then short-cut carbon fibers treated by S1 are injected and a magnetic field is applied to complete the second stage extrusion to obtain extruded granules; S6, gradient molding: The S5 extruded granules are subjected to three stages of molding: heating and pressing, high temperature and high pressure preservation, and gradient cooling, and finally demolded to obtain the finished coating material.

2. The high-performance carbon fiber reinforced coating material according to claim 1, characterized in that, The components of the coating material, by weight percentage, are: polyetheretherketone resin 22-58.5%, chopped carbon fiber 25-40%, silicon carbide nanowires 3-8%, polyimide micro powder 5-10%, epoxy resin 3-6%, aminosilane coupling agent 0.5-2%, and phosphorus-nitrogen synergistic flame retardant 5-12%.

3. The high-performance carbon fiber reinforced coating material according to claim 1, characterized in that, The chopped carbon fibers have a length of 200-500 μm and a single filament diameter of 7 μm; the phosphorus-nitrogen synergistic flame retardant is composed of ammonium polyphosphate and melamine cyanurate in a mass ratio of 2:1; the aminosilane coupling agent is a compound of γ-aminopropyltriethoxysilane and γ-propyltrimethoxysilane in a mass ratio of 3:

1.

4. The high-performance carbon fiber reinforced coating material according to claim 1, characterized in that, S1 specifically includes: S11, acid solution oxidation treatment: immerse short-cut carbon fibers in nitric acid solution and treat at a constant temperature of 70-90℃ for 0.5-2 hours; S12, Washing and Drying: Wash the treated short-cut carbon fibers with deionized water until neutral, and dry them at 100-120℃ for 1-3 hours; S13, Coupling agent impregnation: The dried short-cut carbon fibers are placed in an ethanol solution containing an aminosilane coupling agent, wherein the mass fraction of the aminosilane coupling agent in the ethanol solution is 3-8%, and ultrasonically treated at 40-60℃ for 20-40 minutes. S14, Post-treatment drying: The impregnated short-cut carbon fibers are vacuum filtered and dried at 105-125℃ for 1-2 hours.

5. The high-performance carbon fiber reinforced coating material according to claim 1, characterized in that, S2 specifically includes: S21, Initial mixing: Add silicon carbide nanowires and epoxy resin to a mixing tank at a predetermined mass ratio, and stir at 200-400 r / min for 10-20 minutes. S22, initial grinding: Transfer the S21 mixture to a three-roll mill and perform the first grinding under the conditions of a roll gap of 0.05-0.15mm and a roll temperature of 50-70℃; S23, Circulating fine grinding: Adjust the roller gap to 0.02-0.08mm, and circulate and grind the material 3-7 times at the same roller temperature; S24, Endpoint determination: When the rotational viscosity of the slurry reaches 5000-8000 mPa·s at 25℃, stop grinding to obtain a homogeneous dispersion slurry.

6. The high-performance carbon fiber reinforced coating material according to claim 1, characterized in that, S3 specifically includes: S31, Main Resin Premixing: Add polyetheretherketone resin and polyimide micro powder to a high-speed mixer at a predetermined mass ratio, and mix for 5-10 minutes at 100-130℃ and 500-800r / min. S32, Flame retardant addition: Add phosphorus and nitrogen synergistic flame retardant to the S31 mixture, maintain the temperature, and increase the rotation speed to 800-1200 r / min to mix for 3-8 minutes; S33, Nano slurry blending: The silicon carbide nanowire dispersion slurry obtained in S2 is added simultaneously with the aminosilane coupling agent and mixed for 10-20 minutes at 120-140℃ and 1000-1500r / min. S34, when the material is in a uniform flow state, stop mixing, discharge and cool to room temperature to obtain premixed material.

7. The high-performance carbon fiber reinforced coating material according to claim 1, characterized in that, S4 specifically includes: S41, Loading and Temperature Control: Spread the premixed material obtained in S3 evenly on a quartz tray, controlling the material layer thickness to 2-5mm. After transferring it into the plasma treatment chamber, pre-evacuate to 10⁻²P. a ; S42, Atmosphere replacement: Introduce a mixture of argon and oxygen into the cavity, with oxygen accounting for 10-30% of the volume, and maintain the working pressure at 50-200 Pa. S43, Plasma Activation: Apply radio frequency power with an electrode spacing of 50-80 mm to achieve a power density of 0.5-1.5 W / cm². 2 Processing time: 2-8 minutes; S44, Inertization discharge: After turning off the RF power supply, continuously introduce argon gas for 5-10 minutes, and remove the activated premix when the material temperature drops below 60℃.

8. The high-performance carbon fiber reinforced coating material according to claim 1, characterized in that, S5 specifically includes: S51, Extrusion preparation: Add the activated premix obtained in S4 to the main feed port of the twin-screw extruder, and set the temperatures of the extruder zone IV to 320-340℃, 330-350℃, 340-360℃, 350-370℃, and 360-380℃ respectively. S52, First stage of melt plasticizing: Melt blending is carried out at a screw speed of 100-180 r / min, the melt pressure is maintained at 8-15 MPa, and the residence time is 1-3 minutes; S53, two-stage fiber injection: S1 pretreated short-cut carbon fibers are injected into the feed port of the fourth zone of the extruder. The addition rate is controlled by a loss-in-weight feeder to be 30-50% of the main feed amount. An axial magnetic field with a strength of 0.3-0.8T is applied simultaneously. S54, two-stage extrusion granulation: fiber directional dispersion is completed at a temperature of 360-380℃ in zone V and a screw speed of 150-220r / min, and the material is cut into cylindrical particles with a length of 2-4mm and a diameter of 1.5-2.5mm by a water-cooled pelletizer.

9. The high-performance carbon fiber reinforced coating material according to claim 1, characterized in that, S6 specifically includes: S61, Preheating of material loading: The extruded granules obtained in S5 are evenly filled into the mold cavity, and heated to 390℃ at a rate of 3-5℃ / min under a pressure of 10-15MPa. S62, First-stage pressure molding: Maintain a temperature of 390℃, apply pressure to 20-25MPa and hold pressure for 15-25 minutes; S63, Level 2 High Temperature Curing: Continue heating to 410℃, pressurize to 30-35MPa and hold for 25-35 minutes; S64, Gradient cooling demolding: Cool to 200℃ at a rate of 1-3℃ / min, release the pressure, open the mold and take out the blank; S65, Finished product shaping: The blank is placed in a heat treatment furnace and heated to 230℃ at a rate of 2-4℃ / min and held at that temperature for 1.5-2.5 hours. Finally, it is cooled to room temperature with the furnace to obtain the finished carbon fiber reinforced coating material.

10. A mining cable using the high-performance carbon fiber reinforced sheathing material according to any one of claims 1 to 9.

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