A process for preparing carbon fiber modified plastic composite materials

Abstract

This invention relates to the field of composite material preparation technology, specifically to a process for preparing carbon fiber modified plastic composite materials. The raw materials include a plastic matrix, carbon fibers, an antioxidant compound, and butyl stearate. The antioxidant compound consists of antioxidant 1010 and antioxidant 168 in a 1:1 mass ratio. The carbon fibers undergo plasma surface treatment using an argon-oxygen mixture with a volume ratio of 9:1, a flow rate of 100 sccm, a treatment power of 200 W, and a treatment time of 60 s. This invention uses plasma treatment to activate the carbon fiber surface, improving the fiber surface condition and providing a good foundation for interfacial bonding, thereby enhancing the compatibility between the fiber and the matrix from the source. The multi-stage synergistic modification process can strengthen the interfacial interaction between the fiber and the matrix, forming a stable interfacial structure suitable for the modification needs of various plastic matrices and carbon fibers of different morphologies.

Description

Technical Field

[0001] This invention relates to the field of composite material preparation technology, and specifically to a process for preparing carbon fiber modified plastic composite materials. Background Technology

[0002] Carbon fiber reinforced plastic composites, with their lightweight, high strength, and heat resistance, are widely used in electronics, electrical appliances, and industrial manufacturing, and are one of the core categories of high-performance composite materials. However, the industrial preparation and application of these materials still face many insurmountable technical challenges, limiting their performance upgrades and application scope. Carbon fibers themselves exhibit significant surface chemical inertness, resulting in weak interfacial bonding with conventional plastic matrices. Under external forces, interfacial debonding is prone to occur, failing to fully leverage the reinforcing advantages of carbon fibers. Existing technologies often employ single modification methods to treat carbon fibers, with limited treatment effects and difficulty in achieving a stable bond between the fiber and the matrix.

[0003] The recycling of recycled carbon fiber lacks standardized purification and modification processes. Impurities and resins remaining on the fiber surface directly affect the overall quality of the material, making it difficult to realize the value of resource recycling. The processing characteristics of different plastic matrices vary greatly, and general preparation processes cannot be accurately adapted, easily leading to molding defects. Nano-modified particles are prone to agglomeration in the system, failing to play an interfacial modification role. Improper raw material pretreatment can also cause problems such as internal porosity and cracking.

[0004] In addition, the lack of scientific control over the raw material ratio and the unreasonable amount of fiber added will lead to uneven dispersion, a significant decrease in processing fluidity, and difficulty in achieving stable mass production. Summary of the Invention

[0005] The primary objective of this invention is to provide a process for preparing carbon fiber modified plastic composite materials.

[0006] A further objective of this invention is to provide a carbon fiber modified plastic composite material, the raw materials of which include a plastic matrix, carbon fibers, an antioxidant compound, and butyl stearate; the antioxidant compound is composed of antioxidant 1010 and antioxidant 168 in a mass ratio of 1:1; the carbon fibers are subjected to plasma surface treatment, the gas used for treatment is an argon-oxygen mixture, the volume ratio of argon to oxygen is 9:1, the gas flow rate is 100 sccm, the treatment power is 200W, and the treatment time is 60s.

[0007] Preferably, the plastic matrix is ​​nylon 6, and the carbon fiber is short-cut carbon fiber with a length of 5mm; the raw materials, by weight, include 80 parts of nylon 6, 10 parts of short-cut carbon fiber, 0.5 parts of antioxidant compound, and 0.5 parts of butyl stearate.

[0008] Preferably, it also includes KH560 silane coupling agent; the plastic matrix is ​​nylon 6, and the carbon fiber is short-cut carbon fiber with a length of 5mm; the raw materials, by weight, include 78 parts of nylon 6, 12 parts of short-cut carbon fiber, 2 parts of KH560 silane coupling agent, 0.5 parts of antioxidant compound, and 0.5 parts of butyl stearate.

[0009] Preferably, it also includes a titanate coupling agent and nano-silica with a particle size of 60 nm; the plastic matrix is ​​nylon 66, and the carbon fiber is long-filament carbon fiber with a diameter of 8 μm; the raw materials, by weight, include 70 parts of nylon 66, 15 parts of long-filament carbon fiber, 2 parts of titanate coupling agent, 2 parts of nano-silica, 0.5 parts of antioxidant compound, and 0.5 parts of butyl stearate.

[0010] A method for preparing carbon fiber modified plastic composite material includes carbon fiber modification, raw material drying, melt blending, and molding processing steps; carbon fiber modification is carried out by plasma surface treatment, with the treatment parameters being an argon-oxygen mixed gas volume ratio of 9:1, a gas flow rate of 100 sccm, a power of 200 W, and a time of 60 s; raw material drying is carried out in a vacuum drying oven, controlling the raw material moisture content to be no higher than 0.3%; melt blending is carried out using a twin-screw extruder, with carbon fiber added through a side feed port.

[0011] Preferably, the carbon fiber modification also includes coupling agent grafting treatment; the plasma-treated carbon fiber is immersed in a 1% KH560 ethanol solution with a volume ratio of 9:1 for ethanol to deionized water and a solution pH of 4.5, kept at 70 degrees Celsius for 45 minutes, and then dried at 110 degrees Celsius for 3 hours.

[0012] Preferably, when drying nylon 66, the temperature of the vacuum drying oven is 110 degrees Celsius, the drying time is 10 hours, and the moisture content of the raw material is controlled at 0.2%.

[0013] Preferably, the carbon fiber is recycled carbon fiber, which is first purified by holding at 600 degrees Celsius for 2 minutes, and then subjected to plasma treatment and coupling agent grafting treatment.

[0014] Preferably, a nanoparticle dispersion is added during melt blending; the nanoparticles and coupling agent are mixed at a mass ratio of 1:1, and after adding ethanol, they are dispersed using a 200W ultrasonic device for 12 to 15 minutes.

[0015] Preferably, the molding process is injection molding or compression molding; the injection molding temperature is 210 degrees Celsius to 255 degrees Celsius, and the compression molding temperature is 210 degrees Celsius to 265 degrees Celsius.

[0016] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention uses plasma treatment to activate the surface of carbon fibers, improve the surface condition of the fibers, provide a good foundation for interfacial bonding, and improve the compatibility between the fibers and the matrix from the source; the multi-level synergistic modification process can strengthen the interfacial interaction between the fibers and the matrix, form a stable interfacial structure, and adapt to the modification needs of various plastic matrices and carbon fibers of different morphologies.

[0017] 2. This invention is designed with a dedicated purification and modification process for recycled carbon fiber, which effectively removes impurities from the fiber surface, restores the fiber's performance, realizes resource recycling, and reduces production energy consumption and costs.

[0018] 3. The nanoparticles of this invention are uniformly distributed in the matrix after being specially dispersed, which optimizes the internal structure of the material and expands the application scenarios of the material; the standardized raw material drying process is adapted to the moisture absorption characteristics of different matrices, avoiding defects such as pores and deformation during the molding process, and ensuring the density and structural stability of the material.

[0019] 4. This invention ensures that carbon fibers are uniformly dispersed in the matrix through reasonable raw material ratio and process parameter control, improves processing smoothness, and can be adapted to various molding methods such as injection molding and compression molding to meet the preparation needs of different structural parts.

[0020] 5. The technical solution of the present invention has strong versatility and can be flexibly adapted to various matrices such as nylon, polypropylene, and polytetrafluoroethylene. It takes into account both the stability of material preparation and the quality of finished products, broadens the application boundaries of composite materials, and achieves the unity of efficient production and resource utilization, thus possessing good application value. Detailed Implementation

[0021] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] Example 1: Raw material composition: 80 parts of nylon 6, 10 parts of chopped carbon fiber, 0.5 parts of antioxidant 1010 and antioxidant 168 compound, and 0.5 parts of butyl stearate.

[0023] The chopped carbon fiber has a length of 5mm, and the ratio of antioxidant 1010 to antioxidant 168 is 1:1.

[0024] Preparation steps: The first step is carbon fiber pretreatment. Short carbon fibers are placed in a conventional plasma surface treatment machine and an argon-oxygen mixed gas is introduced. The volume ratio of argon to oxygen is 9:1, the gas flow rate is 100 sccm, the treatment power is 200W, and the treatment time is 60s. The surface of the carbon fiber is etched by plasma bombardment, introducing active groups such as hydroxyl and carboxyl groups, which improves the surface energy of the carbon fiber and removes surface impurities. After treatment, the tensile strength loss of the carbon fiber is controlled within 2.5%.

[0025] The second step is raw material drying. Nylon 6, antioxidant compound, and butyl stearate are placed together in a vacuum drying oven and dried at 100°C for 8 hours to ensure that the moisture content of the raw materials is controlled at 0.3% and to avoid the formation of bubbles during the molding process.

[0026] The third step is melt blending. The dried raw material is added to a twin-screw extruder. The feeding zone temperature is set to 190℃, the melting zone temperature to 235℃, the die head temperature to 245℃, and the screw speed to 120r / min. After the raw material is melted and plasticized, the pretreated chopped carbon fiber is added from the side feed port. Blending continues for 10 minutes to ensure that the carbon fiber is evenly dispersed in the nylon 6 matrix.

[0027] The fourth step is molding and processing. The blended melt is cooled and granulated in a water bath to obtain modified plastic granules. These granules are then injection molded using an injection molding machine at an injection temperature of 245℃, an injection pressure of 100MPa, a holding time of 20s, and a cooling time of 30s to obtain the final product. This product can be used for electronic and electrical appliance housings with ordinary strength requirements.

[0028] Example 2: Raw material composition: 78 parts nylon 6, 12 parts chopped carbon fiber, 2 parts KH560 silane coupling agent, 0.5 parts antioxidant compound, and 0.5 parts butyl stearate.

[0029] The chopped carbon fiber has a length of 5 mm, and the antioxidant compounding ratio is consistent with that in Example 1.

[0030] Preparation steps: The first step involves multi-stage modification of carbon fibers. Short-cut carbon fibers are treated according to the plasma treatment parameters in Example 1. After treatment, they are immediately immersed in a 1% (w / w) KH560 ethanol solution with a volume ratio of ethanol to deionized water of 9:1. The pH of the solution is adjusted to 4.5 to promote the hydrolysis of the coupling agent. The solution is kept at 70°C for 45 min, and then dried at 110°C for 3 h to complete the grafting of the coupling agent. The siloxy group at one end of the coupling agent molecule undergoes a hydrolysis-condensation reaction with the hydroxyl group on the surface of the carbon fiber, while the epoxy group at the other end forms a covalent bond with the amide group in the nylon 6 molecular chain, effectively strengthening the interfacial bonding between the carbon fiber and the nylon 6 matrix.

[0031] The second step is raw material drying, which is completely consistent with the drying steps in Example 1.

[0032] The third step is melt blending. Adjust the parameters of the twin-screw extruder, setting the feeding zone temperature to 195℃, the melting zone temperature to 240℃, the die head temperature to 250℃, and the screw speed to 130r / min. First, melt and plasticize the nylon 6, antioxidant compound, and butyl stearate, then add the multi-stage modified short-cut carbon fibers and blend for 11 minutes to ensure that the coupling agent plays a full role and reduce carbon fiber agglomeration.

[0033] The fourth step is molding and processing. The injection temperature is set to 250℃, the injection pressure to 105MPa, the holding time to 22s, and the cooling time to 32s. The remaining steps are consistent with those in Example 1. Finally, the carbon fiber reinforced nylon 6 composite material with plasma-coupling agent synergistic modification is obtained.

[0034] Example 3: In this embodiment, the plastic matrix is ​​replaced with nylon 66, the carbon fiber is changed to a filament type, and nano-silica is added to achieve three-level synergistic modification of plasma-coupling agent-nanoparticle.

[0035] Raw material composition: 70 parts nylon 66, 15 parts long filament carbon fiber, 2 parts titanate coupling agent, 2 parts nano silica, 0.5 parts antioxidant compound, and 0.5 parts butyl stearate.

[0036] The diameter of the long carbon fiber is 8μm, the particle size of the nano silica is 60nm, and the antioxidant compounding ratio is consistent with that in Example 1.

[0037] Preparation steps: The first step involves multi-stage modification of carbon fibers. The long-filament carbon fibers are first treated according to the plasma treatment parameters in Example 1, and then premixed with a titanate coupling agent. The amount of titanate coupling agent is 1.2% of the carbon fiber mass. After premixing, the mixture is dried at 70°C for 4 hours. The titanate coupling agent can react with the functional groups on the surface of the carbon fiber at the processing temperature of nylon 66, and at the same time form coordination bonds with the nylon 66 molecular chain, effectively improving the processing fluidity.

[0038] The second step is nanoparticle dispersion. Nano-silica and titanate coupling agent are mixed at a mass ratio of 1:1, a small amount of ethanol is added, and ultrasonic dispersion is carried out for 15 minutes using a 200W ultrasonic device to obtain a uniform nano-dispersion and avoid nanoparticle aggregation.

[0039] The third step is raw material drying. Nylon 66, antioxidant compound, and butyl stearate are placed in a vacuum drying oven and dried at 110°C for 10 hours. Since Nylon 66 has strong water absorption, the drying time and temperature are extended to ensure that the moisture content of the raw materials is controlled at 0.2% to avoid molding defects.

[0040] The fourth step is melt blending. The temperature of the twin-screw extruder is set to 240℃ in the feeding zone, 265℃ in the melting zone, and 275℃ in the die head. The screw speed is 125 r / min. First, Nylon 66, antioxidant compound, and butyl stearate are melt-plasticized. Then, the modified filament carbon fiber and nano-dispersion are added and blended for 13 minutes. The blending speed is controlled to avoid breakage of the filament carbon fiber and to ensure the reinforcing effect.

[0041] The fifth step is molding. Compression molding is used instead of injection molding to meet the molding requirements of complex structural parts. The molding temperature is set to 265℃, the molding pressure to 15MPa, and the holding time to 22min. After cooling to room temperature, the material is demolded to obtain a nanoparticle-modified carbon fiber reinforced nylon 66 composite material.

[0042] Example 4: In this embodiment, the raw materials are recycled carbon fiber and polytetrafluoroethylene, and the modification process and molding parameters are optimized.

[0043] Raw material composition: 65 parts polytetrafluoroethylene, 20 parts recycled carbon fiber, 3 parts KH550 silane coupling agent, 2 parts nano titanium dioxide, and 0.5 parts antioxidant compound.

[0044] The recycled carbon fiber is obtained by crushing and purifying recycled T-300 carbon fiber, with a length of 3mm and a nano titanium dioxide particle size of 50nm. The antioxidant compounding ratio is consistent with that in Example 1.

[0045] Preparation steps: The first step involves the purification and modification of recycled carbon fiber. The recycled carbon fiber is placed in a high-temperature furnace and kept at 600°C for 2 minutes to remove surface impurities and residual resin. After cooling, it is treated according to the plasma treatment parameters in Example 1, and then grafted with KH550 ethanol solution according to the coupling agent treatment steps in Example 2. After purification and modification, the tensile strength of the recycled carbon fiber reaches 78% of that of the original carbon fiber, thus ensuring the reinforcing effect while achieving resource recycling.

[0046] The second step involves premixing the nanoparticles with polytetrafluoroethylene (PTFE). PTFE, nano-titanium dioxide, and an antioxidant compound are placed in a high-speed mixer, set to a speed of 250 rpm, and mixed for 8 minutes. The synergistic effect of nano-titanium dioxide and PTFE further enhances the wear resistance and thermal stability of the composite material.

[0047] The third step is melt blending. Taking into account the processing characteristics of polytetrafluoroethylene (PTFE), a Banbury mixer is used for melt blending. The Banbury temperature is set at 200℃, the Banbury time is 13 minutes, and the speed is 80 r / min. First, the premixed PTFE mixture is added to the Banbury mixer for plasticization, and then the modified recycled carbon fiber is added. The mixture is blended for another 5 minutes to ensure that the recycled carbon fiber and PTFE are uniformly mixed. An interfacial bond is constructed through a coupling agent to solve the problem of poor compatibility between recycled carbon fiber and PTFE.

[0048] The fourth step is molding. The molding temperature is set to 210℃, the molding pressure to 20MPa, and the holding time to heat and pressure to 30min. After cooling and demolding, the material is annealed at 210℃ for 3h to eliminate molding stress and obtain the wear-resistant composite material of recycled carbon fiber modified polytetrafluoroethylene.

[0049] Example 5: This embodiment uses a blend matrix of nylon 6 and nylon 66, and optimizes the coupling agent system and raw material ratio.

[0050] Raw material composition: 45 parts of Nylon 6, 30 parts of Nylon 66, 15 parts of chopped carbon fiber, 2 parts of KH560 silane coupling agent and titanate coupling agent compound, 2 parts of nano silica, 0.5 parts of antioxidant compound, and 0.5 parts of butyl stearate.

[0051] The chopped carbon fiber has a length of 5 mm, the mass ratio of KH560 silane coupling agent to titanate coupling agent is 1:1, the nano silica particle size is 60 nm, and the antioxidant compounding ratio is consistent with that in Example 1.

[0052] Preparation steps: The first step is multi-stage modification of carbon fiber. Short-cut carbon fibers are treated according to the plasma-coupling agent synergistic modification steps in Example 2. The coupling agent adopts a compound system to balance interfacial bonding strength and processing fluidity.

[0053] The second step is the pretreatment of the blend matrix. Nylon 6 and Nylon 66 are mixed in proportion and placed in a vacuum drying oven to dry at 105°C for 12 hours to ensure that the moisture content of the raw materials is controlled at 0.3%. The blending of Nylon 6 and Nylon 66 can improve the performance defects of a single matrix. Nylon 6 improves the toughness of the composite material, while Nylon 66 improves the heat resistance of the composite material, thus achieving synergistic optimization of performance.

[0054] The third step is melt blending. The temperature of the twin-screw extruder is set to 200℃ in the feeding zone, 245℃ in the melting zone, and 255℃ in the die head. The screw speed is 130 r / min. First, the Nylon 6 and Nylon 66 blend matrix, antioxidant compound, and butyl stearate are melt-plasticized. Then, the modified short-cut carbon fibers and nano-silica are added and blended for 14 min to ensure that each component is evenly dispersed. The nano-silica further enhances the interfacial effect.

[0055] The fourth step is molding and processing. The injection temperature is set to 255℃, the injection pressure to 110MPa, the holding time to 28s, and the cooling time to 38s, to obtain a multi-stage modified carbon fiber reinforced nylon 6 / nylon 66 blend matrix composite material.

[0056] Example 6: In this embodiment, the matrix is ​​replaced with polypropylene, and the process parameters are optimized to suit the processing characteristics of polypropylene.

[0057] Raw material composition: 75 parts polypropylene, 13 parts chopped carbon fiber, 2 parts KH560 silane coupling agent, 1.5 parts nano zinc oxide, 0.5 parts antioxidant compound, and 0.5 parts butyl stearate.

[0058] The chopped carbon fiber has a length of 4 mm, the nano zinc oxide has a particle size of 60 nm, and the antioxidant compounding ratio is consistent with that in Example 1.

[0059] Preparation steps: The first step is multi-stage modification of carbon fiber. Short-cut carbon fibers are treated with plasma treatment parameters according to Example 1, and then grafted with KH560 silane coupling agent according to the coupling agent grafting method of Example 2 to ensure that the coupling agent grafting rate meets the standard and improve the compatibility with polypropylene matrix.

[0060] The second step is nanoparticle dispersion. Nano zinc oxide and KH560 silane coupling agent are mixed at a mass ratio of 1:1, a small amount of ethanol is added, and the mixture is ultrasonically dispersed for 12 minutes using a 200W ultrasonic device to obtain a uniform nano-dispersion.

[0061] The third step is raw material drying. Polypropylene, antioxidant compound, and butyl stearate are placed in a vacuum drying oven and dried at 80°C for 6 hours to ensure that the moisture content of the raw materials is controlled at 0.3% to match the processing characteristics of polypropylene.

[0062] The fourth step is melt blending. The temperature of the twin-screw extruder is set to 170℃ in the feeding zone, 200℃ in the melting zone, and 210℃ in the die head. The screw speed is 140 r / min. Taking into account the low melting point of polypropylene, the process parameters are optimized. First, polypropylene, antioxidant compound, and butyl stearate are melt-plasticized. Then, the modified short-cut carbon fibers and nano-dispersion are added and blended for 12 min.

[0063] The fifth step is molding and processing. The injection temperature is set to 210℃, the injection pressure to 95MPa, the holding time to 18s, and the cooling time to 28s, to obtain a multi-stage modified carbon fiber reinforced polypropylene composite material.

[0064] Comparative Example 1: The raw material composition is exactly the same as in Example 1, except that the plasma pretreatment step of carbon fiber is omitted, and the rest of the preparation steps are exactly the same as in Example 1.

[0065] In this comparative example, no surface modification was performed on the carbon fiber. The carbon fiber surface was smooth, chemically inert, and had low surface energy. The interfacial bond with the nylon 6 matrix was extremely weak, resulting in low stress transfer efficiency. The carbon fiber was easily pulled out of the matrix, and its reinforcing effect could not be fully utilized. Its overall performance was far lower than that of Example 1.

[0066] Comparative Example 2: The raw material composition is exactly the same as in Example 2, except that the plasma treatment step of carbon fiber is omitted and KH560 silane coupling agent is used to treat carbon fiber directly. The rest of the preparation steps are exactly the same as in Example 2.

[0067] This comparative example did not employ plasma-coupling agent synergistic modification, resulting in insufficient active groups on the carbon fiber surface. Consequently, the coupling agent grafting rate was low, and the interfacial bonding strength was significantly lower than in Example 2, making it difficult to achieve optimal improvement in the mechanical properties of the composite material.

[0068] Comparative Example 3: Raw material composition: 50 parts nylon 6, 40 parts short-cut carbon fiber, 3 parts KH560 coupling agent, 2 parts antioxidant compound, 2 parts butyl stearate, and the remaining preparation steps are the same as in Example 2.

[0069] In this comparative example, the carbon fiber content exceeds the scope of this invention. During the melt blending process, the carbon fiber is difficult to disperse evenly and is prone to agglomeration, resulting in a large number of defects inside the composite material. The mechanical properties are reduced, and the processing fluidity is extremely poor, making it impossible to achieve normal molding.

[0070] Comparative Example 4: The raw material composition is exactly the same as in Example 3. The raw material drying step is omitted, and the melt blending and molding process is carried out directly. The remaining preparation steps are exactly the same as in Example 3.

[0071] In this comparative example, the raw materials contain adsorbed water. During the melt blending process, the water vaporizes and generates bubbles, which leads to an increase in the internal porosity of the composite material, a decrease in density, and a significant reduction in mechanical and heat resistance properties. After molding, defects such as cracking and deformation are likely to occur.

[0072] Comparative Example 5: Raw material composition: 72 parts nylon 66, 15 parts long carbon fiber, 2 parts titanate coupling agent, 0.5 parts antioxidant compound, 0.5 parts butyl stearate, and the remaining preparation steps are the same as in Example 3.

[0073] This comparative example did not include nanoparticles, so it could not form a composite interface layer between the carbon fiber and the nylon 66 matrix. The interfacial mechanical interlocking effect was insufficient, and the heat resistance, wear resistance and impact toughness of the composite material were all lower than those of Example 3.

[0074] Comparative Example 6: The raw material composition is exactly the same as in Example 4. The purification and modification steps of recycled carbon fiber are omitted. The recycled carbon fiber is directly blended with other raw materials. The remaining preparation steps are exactly the same as in Example 4.

[0075] In this comparative example, a large amount of impurities and resin remained on the surface of the recycled carbon fiber, which could not form an effective bond with the polytetrafluoroethylene body, and the fiber itself had insufficient strength, resulting in the mechanical properties and wear resistance of the composite material being far lower than those of Example 4.

[0076] Performance testing and results analysis: For all the composite material products prepared in the above embodiments and comparative examples, performance tests were conducted in accordance with relevant national standards. The test items included tensile strength, flexural strength, cantilever beam notched impact strength, heat distortion temperature, interfacial shear strength, density, and wear resistance. Five sets of tests were conducted on each sample, and the average value was taken as the final test result.

[0077] Test standards and methods: (1) Tensile strength: Tested according to GB / T1040-2006 standard, with a 50N load applied by the universal testing machine and a crosshead speed of 5mm / min; (2) Bending strength: Tested according to GB / T9341-2008 standard, with a load of 5N; (3) Notched impact strength of cantilever beam: Tested according to GB / T1843-2008 standard, with a pendulum specification of 2.75J; (4) Heat distortion temperature: Tested according to GB / T1634.2-2004 standard, with a load of 1.80MPa; (5) Interfacial shear strength: The single fiber pull-out method was used for testing, and the universal testing machine speed was 0.5 mm / min; (6) Density: Tested according to GB / T1033.1-2008 standard, using the specific gravity bottle method; (7) Abrasion resistance: Tested according to the Martindale abrasion resistance test standard, with 5000 friction cycles, and the wear amount of the test surface was measured. The test results are shown in Table 1 below: Table 1: Results analysis: Example 1 employed a basic plasma modification process, achieving tensile strength and interfacial shear strength of 150 MPa and 22 MPa, respectively, representing increases of 87.5% and 120% compared to the unmodified Comparative Example 1. This result demonstrates that plasma pretreatment of carbon fibers effectively enhances their surface activity, strengthens the interfacial bonding with the plastic matrix, and fully leverages the reinforcing effect of carbon fibers. Example 2 utilized a plasma-coupling agent synergistic modification process, further increasing tensile strength and interfacial shear strength to 170 MPa and 26 MPa, respectively, representing increases of 41.7% and 52.9% compared to the single-coupling agent modified Comparative Example 2. This proves that synergistic modification significantly enhances interfacial bonding compared to single modification, resulting in a substantial improvement in the mechanical properties of the composite material. Example 3 introduced nanoparticles to achieve three-level synergistic modification. Simultaneously changing the plastic matrix and carbon fiber type, the tensile strength and heat distortion temperature reached 190 MPa and 210℃ respectively, which are 35.7% and 13.5% higher than those of Comparative Example 5 without nanoparticles. This indicates that the three-level synergistic modification can not only improve the mechanical properties of the composite material, but also optimize its heat resistance and expand the matrix compatibility range. Example 4 uses an integrated process of purified and modified recycled carbon fiber, and its tensile strength reaches 100 MPa, which is 66.7% higher than that of Comparative Example 6 without purification and modification. This shows that the process can effectively restore the reinforcing properties of recycled carbon fiber, achieving resource recycling while ensuring product performance meets standards. Example 5 uses a nylon 6 / nylon 66 blend matrix, which takes into account the mechanical properties and processing properties of the composite material, with a tensile strength of 180 MPa and an impact strength of 29 kJ / m. 2 With balanced overall performance, it can be adapted to mid-to-high-end application scenarios; Example 6 extends the plastic matrix to polypropylene, with a tensile strength of 140MPa and a heat distortion temperature of 185℃, which meets the usage requirements of electronic and electrical appliance housings.

[0078] Comparative Example 3, due to its carbon fiber content exceeding the scope of this invention, resulted in processing difficulties and performance degradation, thus confirming the rationality of the raw material ratio of this invention. Comparative Example 4, due to the lack of raw material drying, exhibited molding defects, highlighting the necessity of the raw material pretreatment step.

[0079] Overall, this invention effectively solves the core technical problems of the prior art through three-level synergistic modification, raw material adaptation and control, and process parameter optimization.

[0080] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention.

Claims

1. A carbon fiber modified plastic composite material, characterized in that, The raw materials include a plastic matrix, carbon fiber, antioxidant compound, and butyl stearate; the antioxidant compound is composed of antioxidant 1010 and antioxidant 168 in a mass ratio of 1:1; the carbon fiber undergoes plasma surface treatment, the gas used for treatment is an argon-oxygen mixture with an argon to oxygen volume ratio of 9:1, a gas flow rate of 100 sccm, a treatment power of 200W, and a treatment time of 60s.

2. The composite material according to claim 1, characterized in that, The plastic matrix is ​​nylon 6, and the carbon fiber is short-cut carbon fiber with a length of 5mm. The raw materials, by weight, include 80 parts of nylon 6, 10 parts of short-cut carbon fiber, 0.5 parts of antioxidant compound, and 0.5 parts of butyl stearate.

3. The composite material according to claim 1, characterized in that, It also includes KH560 silane coupling agent; the plastic matrix is ​​nylon 6, and the carbon fiber is short-cut carbon fiber with a length of 5mm; the raw materials, by weight, include 78 parts of nylon 6, 12 parts of short-cut carbon fiber, 2 parts of KH560 silane coupling agent, 0.5 parts of antioxidant compound, and 0.5 parts of butyl stearate.

4. The composite material according to claim 1, characterized in that, It also includes titanate coupling agent and nano-silica with a particle size of 60nm; the plastic matrix is ​​nylon 66, and the carbon fiber is long filament carbon fiber with a diameter of 8μm; the raw materials, by weight, include 70 parts of nylon 66, 15 parts of long filament carbon fiber, 2 parts of titanate coupling agent, 2 parts of nano-silica, 0.5 parts of antioxidant compound, and 0.5 parts of butyl stearate.

5. A method for preparing a carbon fiber modified plastic composite material, used to prepare the composite material according to any one of claims 1 to 4, characterized in that, The process includes carbon fiber modification, raw material drying, melt blending, and molding. Carbon fiber modification is performed using plasma surface treatment with the following parameters: argon-oxygen mixed gas volume ratio of 9:1, gas flow rate of 100 sccm, power of 200 W, and time of 60 s. Raw material drying is carried out in a vacuum drying oven, with the raw material moisture content controlled to be no higher than 0.3%. Melt blending is performed using a twin-screw extruder, with carbon fiber added through the side feed port.

6. The preparation method according to claim 5, characterized in that, Carbon fiber modification also includes coupling agent grafting treatment; the plasma-treated carbon fiber is immersed in a 1% KH560 ethanol solution with a volume ratio of 9:1 for ethanol to deionized water and a solution pH of 4.5, kept at 70 degrees Celsius for 45 minutes, and then dried at 110 degrees Celsius for 3 hours.

7. The preparation method according to claim 5, characterized in that, When drying nylon 66 raw materials, the temperature of the vacuum drying oven is 110 degrees Celsius, the drying time is 10 hours, and the moisture content of the raw materials is controlled at 0.2%.

8. The preparation method according to claim 5, characterized in that, The carbon fiber is recycled carbon fiber. The recycled carbon fiber is first purified by holding at a high temperature of 600 degrees Celsius for 2 minutes, and then subjected to plasma treatment and coupling agent grafting treatment.

9. The preparation method according to claim 5, characterized in that, Add nanoparticle dispersion during melt blending; mix nanoparticles and coupling agent at a mass ratio of 1:1, add ethanol, and disperse using a 200W ultrasonic device for 12 to 15 minutes.

10. The preparation method according to claim 5, characterized in that, The molding process uses injection molding or compression molding; the injection molding temperature is 210 degrees Celsius to 255 degrees Celsius, and the compression molding temperature is 210 degrees Celsius to 265 degrees Celsius.

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