Carbon fiber needled felt and preparation method thereof
By treating carbon fiber, basalt fiber, and glass fiber with argon-oxygen mixed plasma and performing composite grafting modification, combined with composite coupling agents, the problem of poor interfacial bonding performance of carbon fiber products was solved, and high-performance composite fiber materials were prepared, suitable for multiple application scenarios.
Patent Information
- Application Number
- CN202511243798.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-02
- Publication Date
- 2025-10-28
AI Technical Summary
Existing carbon fiber products have poor interfacial bonding performance, which limits their application in composite materials. Traditional plasma treatment has limited effectiveness, and the formulation and process of grafting modifiers need to be optimized.
Argon-oxygen mixed gas plasma treatment is used to treat the fiber surface, introducing active groups. Combined with composite grafting modification and composite coupling agent treatment, the preparation process parameters are optimized, and carbon fiber, basalt fiber and glass fiber are used to form a multifunctional composite fiber material.
It significantly improves the interfacial bonding force between fibers, enhances the mechanical properties and high-temperature resistance of carbon fiber needle-punched felt, and has a simple, environmentally friendly process that is easy to industrialize.
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Figure CN120844282A_ABST
Abstract
Description
Technical Field
[0001] This application belongs to the field of fiber materials technology, specifically relating to a carbon fiber needled felt and its preparation method, which belongs to the preparation and application technology of multifunctional composite fiber materials. Background Art
[0002] With the continuous development of industrial technology, the demand for high-performance fiber materials is increasing. Carbon fiber possesses excellent properties such as high strength, high modulus, low density, and resistance to high and low temperatures, and has been widely used in many fields. However, pure carbon fiber products still have some shortcomings, such as poor interfacial bonding performance with other materials, which limits their further application in composite materials.
[0003] Currently, there are many methods for modifying fiber surfaces, such as chemical reagent treatment, plasma treatment, and grafting modification. Plasma treatment can introduce active groups into the fiber surface, improving its surface activity, but the effect of plasma treatment alone is limited. Grafting modification can graft specific functional groups onto the fiber surface, improving fiber compatibility and interfacial bonding properties, but traditional grafting modifier formulations and processes need to be optimized to improve grafting efficiency and modification effect.
[0004] Therefore, this application provides a carbon fiber needled felt and its preparation method, which solves the problems existing in the prior art and improves the comprehensive performance of carbon fiber needled felt by plasma treatment, composite grafting modification and composite coupling agent treatment of fibers, and optimizing the preparation process parameters.
[0005] Application content
[0006] To address these issues, the purpose of this application is to overcome the shortcomings of existing technologies and provide a carbon fiber needled felt and its preparation method. This carbon fiber needled felt, through a rational combination of carbon fiber, basalt fiber, and glass fiber, and employing plasma treatment, composite grafting modification, and coupling treatment, significantly enhances the interfacial bonding force between fibers, exhibiting excellent mechanical properties, high-temperature resistance, and chemical stability. Furthermore, the preparation method is simple, uses mild reaction conditions, is environmentally friendly, and is easily scalable for industrial production.
[0007] To achieve the above-mentioned technical objectives, this application provides the following technical solution:
[0008] In the first aspect, a carbon fiber needled felt includes carbon fiber, basalt fiber, glass fiber, composite grafting modifier, dispersant, and composite coupling agent.
[0009] Carbon fiber, basalt fiber, and alkali-free glass fiber were treated with argon-oxygen mixed gas plasma. Argon, as an inert gas, generates high-energy columns in the plasma state, physically bombarding the fiber surface, breaking the original chemical bonds, forming micro-pits, increasing surface roughness, and expanding the specific surface area. Meanwhile, oxygen reacts with unsaturated bonds on the fiber surface in the plasma environment, generating active groups such as hydroxyl (-OH) and carboxyl (-COOH). These active groups and the rough surface provide more "anchoring points" for subsequent bonding with composite grafting modifiers and composite coupling agents, significantly improving the interfacial bonding ability between the fiber and other components, and avoiding the delamination problem caused by a smooth fiber surface and low activity after composite bonding.
[0010] The composite grafting modifier consists of a main grafting monomer, auxiliary grafting monomers, and an initiator. The main grafting monomer is maleic anhydride, and the auxiliary grafting monomers include any one or more of acrylic acid, itaconic acid, and acrylamide. The initiator includes any one of ammonium persulfate and benzoyl peroxide. Maleic anhydride, as the main grafting monomer, contains a double bond and two carboxyl groups in its molecule. It can not only undergo an addition reaction with free radicals on the fiber surface to achieve grafting, but its carboxyl groups can also chemically react with groups in subsequent coupling agents, such as the amino groups in silane coupling agents. Auxiliary grafting monomers such as acrylic acid and itaconic acid can copolymerize with maleic anhydride and free radicals on the fiber surface through double bonds. Furthermore, their own carboxyl and amide groups can further enrich the functional groups on the fiber surface, enhance the compatibility of the fiber with dispersants and coupling agents, and improve the dispersibility of the fiber in subsequent processing, preventing fiber agglomeration.
[0011] Furthermore, the mass ratio of carbon fiber, basalt fiber, glass fiber, composite graft modifier, dispersant, and composite coupling agent is (49-65):(15-20):(10-15):(3-5):(2-4):(5-7).
[0012] Furthermore, the carbon fiber is a medium-modulus T700 polyacrylonitrile-based carbon fiber; the glass fiber is an alkali-free glass fiber; and the dispersant is polyethylene glycol 400. Compared to pitch-based and viscose-based carbon fibers, medium-modulus T700 polyacrylonitrile-based carbon fiber combines high strength, high modulus, and good corrosion resistance, while also being moderately priced. Alkali-free glass fiber exhibits stronger water resistance and corrosion resistance compared to medium-alkali and high-alkali glass fibers. Polyethylene glycol 400 is a non-ionic dispersant; the ether bonds and hydroxyl groups in its molecular chain can form hydrogen bonds with the carboxyl and hydroxyl groups on the fiber surface, and its hydrophilicity improves the fiber's dispersibility in aqueous solutions.
[0013] Furthermore, the composite coupling agent is composed of a silane coupling agent and a titanate coupling agent, with a mass ratio of 2-2.5:1 between the silane coupling agent and the titanate coupling agent.
[0014] Furthermore, the silane coupling agent includes any one of KH-550 and KH-570; the titanate coupling agent includes any one of monoalkoxy isopropyltristearate titanate and bis(dioctylpyrophosphate)ethylene titanate. The siloxane coupling agent, such as KH-550 and KH-570, has a siloxane group at one end that can hydrolyze to generate silanol groups, which undergo a condensation reaction with the hydroxyl groups on the fiber surface. The organic groups at the other end, such as amino groups or double bonds, can react with the resin or adhesive components in the subsequent curing process. The titanate coupling agent can bind to the carboxyl and hydroxyl groups on the fiber surface through its titanium-oxygen bonds, while its long-chain alkyl groups can improve the compatibility between the fiber and the organic matrix.
[0015] Furthermore, the mass ratio of the main grafting monomer, auxiliary grafting monomer and initiator in the composite grafting modifier is (68-79.5):(20-30):(0.5-2).
[0016] Secondly, a method for preparing carbon fiber needled felt includes the following steps:
[0017] Carbon fiber, basalt fiber, and alkali-free glass fiber were treated with argon-oxygen mixed gas plasma, with a treatment power of 80-120W. The treatment time was 15-20 minutes for carbon fiber, 10-15 minutes for basalt fiber, and 8-12 minutes for glass fiber. The argon to oxygen volume ratio was 3:1, and the vacuum degree was 0.08-0.1 MPa.
[0018] The carbon fibers, basalt fibers, and glass fibers treated with argon-oxygen mixed gas plasma were mixed in a certain mass ratio and then dispersed in a dispersant to obtain mixed fibers. The mixed fibers were then immersed in a composite grafting modifier solution and reacted at 80-90℃ for 2-3 hours. After the reaction, the fibers were rinsed with deionized water 3-5 times and then dried in a vacuum drying oven at 80-100℃ and 0.06-0.08MPa for 4-6 hours to obtain modified mixed fibers.
[0019] The modified mixed fibers were immersed in a composite coupling agent solution and treated at 60-70℃ for 1-1.5h. After the reaction was completed, they were dried in an oven at 110-120℃ for 2-3h to obtain the coupled mixed fibers.
[0020] The coupled-treated mixed fibers are fed into a carding machine at a carding speed of 10-15 m / min, and carded to a areal density of 200-300 g / m². 2 The fiber web is then fed into a needle punching machine for reinforcement, with a needle punching density of 100-300 needles / cm². 2 The needle-punching depth is 5-10mm to obtain a needle-punched felt blank;
[0021] The needle-punched felt blank is placed in a hot air circulating oven with a wind speed of 1-2 m / s, preheated at 120-140℃ for 1-2 h, cured at 180-200℃ for 3-4 h, and finally cooled to room temperature at a rate of 5-10℃ / min to obtain carbon fiber needle-punched felt.
[0022] Furthermore, before argon-oxygen mixed gas plasma treatment, carbon fiber, basalt fiber, and glass fiber undergo fiber cutting and surface impurity removal to adapt to subsequent combing and needle punching processes.
[0023] Furthermore, the preparation method of the composite grafting modifier solution includes slowly adding maleic anhydride to deionized water while stirring, followed by adding auxiliary grafting monomers and initiators in sequence, and continuing to stir for 20-25 minutes, during which the solution temperature is controlled not to exceed 35°C; the mass fraction of the composite grafting modifier solution is 12%-18%.
[0024] Furthermore, the preparation method of the composite coupling agent solution includes first mixing the silane coupling agent and the titanate coupling agent, then adding deionized water and stirring until homogeneous, and adjusting the pH of the solution to 5-6 with acetic acid; the mass fraction of the composite coupling agent solution is 4%-6%.
[0025] Furthermore, the carding machine includes either a roller carding machine or a cover carding machine; the reinforcement method during the needle punching process is alternating puncture by upper and lower needles.
[0026] Beneficial technical effects:
[0027] By treating carbon fiber, basalt fiber, and alkali-free glass fiber with argon-oxygen mixed plasma, argon gas is excited into a plasma state, generating a large number of high-energy particles. When these high-energy columns bombard the fiber surface at high speed, they break down the original dense molecular structure of the fiber surface. Simultaneously with the physical action of argon gas, oxygen in the plasma environment is excited into reactive oxygen species, such as oxygen atoms, ozone, and oxygen ions. These reactive species undergo addition reactions with the unsaturated bonds generated on the fiber surface by physical bombardment, thereby introducing active groups such as hydroxyl and carboxyl groups, providing sufficient functional groups for the subsequent grafting process. This solves the problem of low surface activity and poor compatibility with other components in traditional fiber composites, which leads to delamination.
[0028] Maleic anhydride molecules possess both double bonds (C=C) and dicarboxyl groups (-COOH). The double bonds undergo addition reactions with free radicals on the fiber surface, achieving grafting. The carboxyl groups react chemically with composite coupling agents, such as amidation reactions between carboxyl and amino groups, and coordination reactions between carboxyl and titanium-oxygen bonds, thereby further strengthening the interfacial bonding. Attached Figure Description
[0029] Figure 1 This is a flowchart of the preparation method of the carbon fiber needled felt described in this application.
[0030] Figure 2 This is a photograph of the carbon fiber needled felt prepared in Example 1. Detailed Implementation
[0031] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, a detailed description of specific embodiments of this application will be provided below.
[0032] Many specific details are set forth in the following description in order to provide a full understanding of this application. However, this application may also be implemented in other ways different from those described herein. Those skilled in the art can make similar extensions without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.
[0033] Example 1
[0034] like Figure 1 As shown in the figure, this embodiment provides a method for preparing carbon fiber needled felt, and the specific operation method includes the following steps:
[0035] 1. Take medium modulus T700 polyacrylonitrile-based carbon fiber, basalt fiber, and alkali-free glass fiber, and treat them with plasma using an argon-oxygen mixed gas (volume ratio 3:1), with a treatment power of 80W and a vacuum degree of 0.08MPa; the treatment time for carbon fiber is 15min, the treatment time for basalt fiber is 10min, and the treatment time for alkali-free glass fiber is 8min.
[0036] 2. Mix the plasma-treated medium-modulus T700 carbon fiber, basalt fiber, glass fiber, and dispersant according to the mass ratio to obtain mixed fibers; slowly add maleic anhydride to deionized water while stirring, then add acrylic acid and ammonium persulfate in sequence, and continue stirring for 25 minutes, controlling the solution temperature not to exceed 35°C, to prepare a composite grafting modifier solution with a mass fraction of 12%; immerse the mixed fibers in the solution and react at 80°C for 2 hours; after the reaction, rinse three times with deionized water, and then dry in a vacuum drying oven at 80°C and 0.06MPa for 4 hours to obtain modified mixed fibers;
[0037] The mass ratio of maleic anhydride, acrylic acid, and ammonium persulfate is 75:23:2.
[0038] 3. Take silane coupling agent KH-550 and titanate coupling agent monoalkoxy type isopropyltristearate titanate, mix them, add deionized water and stir evenly, adjust the pH value to 5 with acetic acid, and prepare a composite coupling agent solution with a mass fraction of 4%; immerse the modified mixed fiber in the composite coupling agent solution, treat at 60℃ for 1 hour, after the reaction is completed, dry in an oven at 110℃ for 2 hours to obtain the coupled mixed fiber;
[0039] Among them, KH-550, the mass ratio of monoalkoxy isopropyl tristearate titanate is 2:1;
[0040] 4. Feed the coupled mixed fibers into a roller carding machine, set the carding speed to 10m / min, and card to an areal density of 200g / m². 2 The fiber web is fed into a needle punching machine, where it is reinforced by alternating upper and lower needles, with a needle density of 100 needles / cm². 2 A needle-punching depth of 5mm was used to obtain a needle-punched felt blank.
[0041] 5. Place the needle-punched felt blank in a hot air circulating oven, set the wind speed to 1m / s, preheat at 120℃ for 1h, then raise the temperature to 180℃ for 3h, and finally cool to room temperature at a rate of 5℃ / min to obtain carbon fiber needle-punched felt.
[0042] In steps 1 to 5 above, the mass ratio of medium modulus T700 polyacrylonitrile-based carbon fiber, basalt fiber, glass fiber, composite grafting modifier, dispersant, and composite coupling agent is 55:18:14:4:3:6.
[0043] like Figure 2 The image shown is a physical picture of the carbon fiber needled felt prepared in Example 1.
[0044] Example 2
[0045] like Figure 1 As shown in the figure, this embodiment provides a method for preparing carbon fiber needled felt, and the specific operation method includes the following steps:
[0046] 1. Take medium modulus T700 polyacrylonitrile-based carbon fiber, basalt fiber, and alkali-free glass fiber, and perform plasma treatment using an argon-oxygen mixed gas volume ratio of 3:1. Set the treatment power to 100W and the vacuum degree to 0.09MPa. The treatment time for carbon fiber is 17min, the treatment time for basalt fiber is 12min, and the treatment time for alkali-free glass fiber is 10min.
[0047] 2. Mix the plasma-treated medium-modulus T700 carbon fiber, basalt fiber, glass fiber, and dispersant according to the mass ratio to obtain mixed fibers; slowly add maleic anhydride to deionized water while stirring, then add itaconic acid and benzoyl peroxide in sequence, and continue stirring for 23 minutes, controlling the solution temperature not to exceed 35°C, to prepare a composite grafting modifier solution with a mass fraction of 15%; immerse the mixed fibers in the solution and react at 85°C for 2.5 hours, then rinse four times with deionized water and dry in a vacuum drying oven at 90°C and 0.07 MPa for 5 hours to obtain modified mixed fibers;
[0048] The mass ratio of maleic anhydride, itaconic acid, and benzoyl peroxide is 68:30:2.
[0049] 3. Take silane coupling agent KH-570 and titanate coupling agent di(dioctylpyrophosphoryloxy)ethylene titanate, mix them, add deionized water and stir evenly. Adjust the pH value to 5.5 with acetic acid to prepare a 5% (w / w) composite coupling agent solution. Immerse the modified mixed fiber in the solution and treat it at 65℃ for 1.2h. After the reaction is completed, dry it in an oven at 115℃ for 2.5h to obtain the coupled mixed fiber.
[0050] The mass ratio of KH-570 to bis(dioctylpyrophosphoryloxy)ethylene titanate is 2.2:1.
[0051] 4. Feed the coupled mixed fibers into the carding machine, set the carding speed to 12m / min, and card to an areal density of 250g / m². 2 The fiber mesh is fed into a needle punching machine, where it is reinforced by alternating upper and lower needles, with a needle density of 200 needles / cm². 2 A needle-punching depth of 7mm was used to obtain a needle-punched felt blank.
[0052] 5. Place the needle-punched felt blank in a hot air circulating oven, set the wind speed to 1.5 m / s, preheat at 130℃ for 1.5 h, then raise the temperature to 190℃ for curing for 3.5 h, and finally cool to room temperature at a rate of 7℃ / min to obtain carbon fiber needle-punched felt.
[0053] In steps 1 to 5 above, the mass ratio of medium modulus T700 polyacrylonitrile-based carbon fiber, basalt fiber, glass fiber, composite grafting modifier, dispersant, and composite coupling agent is 56:17:13:5:4:5.
[0054] Example 3
[0055] like Figure 1 As shown in the figure, this embodiment provides a method for preparing carbon fiber needled felt, and the specific operation method includes the following steps:
[0056] 1. Take T700 polyacrylonitrile-based carbon fiber, basalt fiber, and alkali-free glass fiber with medium modulus, and perform plasma treatment using an argon-oxygen mixed gas volume ratio of 3:1. Set the treatment power to 110W and the vacuum degree to 0.095MPa. The treatment time for carbon fiber is 18min, the treatment time for basalt fiber is 14min, and the treatment time for alkali-free glass fiber is 11min.
[0057] 2. Mix the plasma-treated medium-modulus T700 carbon fiber, basalt fiber, glass fiber, and dispersant according to the mass ratio to obtain mixed fibers; slowly add maleic anhydride to deionized water while stirring, then add acrylamide and ammonium persulfate in sequence, and continue stirring for 22 minutes, controlling the solution temperature to not exceed 35℃, to prepare a composite grafting modifier solution with a mass fraction of 17%; immerse the mixed fibers in the solution and react at 88℃ for 2.8 hours, then rinse five times with deionized water and dry in a vacuum drying oven at 95℃ and 0.075MPa for 5.5 hours to obtain modified mixed fibers;
[0058] The mass ratio of maleic anhydride, acrylamide, and ammonium persulfate is 79.5:20:0.5.
[0059] 3. Take silane coupling agent KH-550 and titanate coupling agent monoalkoxy type isopropyltristearate titanate, mix them, add deionized water and stir evenly, adjust the pH value to 5.8 with acetic acid, and prepare a composite coupling agent solution with a mass fraction of 5.5%. Immerse the modified mixed fiber in it and treat it at 68℃ for 1.4h. After the reaction is completed, dry it in an oven at 118℃ for 2.8h to obtain the mixed fiber after coupling treatment.
[0060] The mass ratio of KH-550 to monoalkoxy isopropyltristearate titanate is 2.5:1.
[0061] 4. Feed the coupled mixed fibers into a roller carding machine, set the carding speed to 14 m / min, and card to an areal density of 280 g / m². 2 The fiber web is fed into a needle punching machine, where it is reinforced by alternating upper and lower needles, with a needle density of 250 needles / cm². 2 The needle-punching depth is 9mm to obtain a needle-punched felt blank. The needle-punched felt blank is placed in a hot air circulating oven, with the air speed set at 1.8m / s, preheated at 135℃ for 1.8h, then heated to 195℃ for 3.8h, and finally cooled to room temperature at a rate of 9℃ / min to obtain carbon fiber needle-punched felt.
[0062] In steps 1 to 5 above, the mass ratio of medium modulus T700 polyacrylonitrile-based carbon fiber, basalt fiber, glass fiber, composite grafting modifier, dispersant, and composite coupling agent is 62:16:11:5:2:4.
[0063] Example 4
[0064] like Figure 1 As shown in the figure, this embodiment provides a method for preparing carbon fiber needled felt, and the specific operation method includes the following steps:
[0065] 1. Take medium modulus T700 polyacrylonitrile-based carbon fiber, basalt fiber, and alkali-free glass fiber, and perform plasma treatment using an argon-oxygen mixed gas volume ratio of 3:1. Set the treatment power to 120W and the vacuum degree to 0.1MPa. The treatment time is 20min for carbon fiber, 15min for basalt fiber, and 12min for alkali-free glass fiber.
[0066] 2. Mix the plasma-treated medium-modulus T700 carbon fiber, basalt fiber, glass fiber, and dispersant according to the mass ratio to obtain mixed fibers; slowly add maleic anhydride to deionized water while stirring, then add acrylamide and benzoyl peroxide in sequence, and continue stirring for 20 minutes, controlling the solution temperature not to exceed 35°C, to prepare a composite grafting modifier solution with a mass fraction of 18%; immerse the mixed fibers in the solution and react at 90°C for 3 hours, then rinse five times with deionized water and dry in a vacuum drying oven at 100°C and 0.08MPa for 6 hours to obtain modified mixed fibers;
[0067] The mass ratio of maleic anhydride, acrylamide, and benzoyl peroxide is 75:23.5:1.5.
[0068] 3. Take silane coupling agent KH-570 and titanate coupling agent di(dioctylpyrophosphoryloxy)ethylene titanate, mix them, add deionized water and stir evenly, adjust the pH value to 6 with acetic acid, prepare a 6% (w / w) composite coupling agent solution, immerse the modified mixed fiber in it, treat at 70℃ for 1.5h, after the reaction is completed, dry in an oven at 120℃ for 3h to obtain the coupled mixed fiber;
[0069] The mass ratio of KH-570 to bis(dioctylpyrophosphoryloxy)ethylene titanate is 2:1.
[0070] 4. Feed the coupled mixed fibers into the carding machine, set the carding speed to 15m / min, and card to an areal density of 300g / m². 2 The fiber mesh is fed into a needle punching machine, where it is reinforced by alternating upper and lower needles, with a needle density of 300 needles / cm². 2 The needle-punching depth is 10 mm to obtain a needle-punched felt blank. The needle-punched felt blank is placed in a hot air circulating oven, the wind speed is set to 2 m / s, and it is preheated at 140℃ for 2 h. Then the temperature is raised to 200℃ and cured for 4 h. Finally, it is cooled to room temperature at a rate of 10℃ / min to obtain carbon fiber needle-punched felt.
[0071] In steps 1 to 5 above, the mass ratio of medium modulus T700 polyacrylonitrile-based carbon fiber, basalt fiber, glass fiber, composite grafting modifier, dispersant, and composite coupling agent is 65:15:10:3:2:5.
[0072] Comparative Example 1
[0073] This embodiment provides a method for preparing carbon fiber needled felt, the specific operation method including the following steps:
[0074] 1. Take medium modulus T700 polyacrylonitrile-based carbon fiber, basalt fiber, and alkali-free glass fiber, and perform plasma treatment using an argon-oxygen mixed gas volume ratio of 3:1. Set the treatment power to 80W and the vacuum degree to 0.08MPa. The treatment time is 15min for carbon fiber, 10min for basalt fiber, and 8min for alkali-free glass fiber.
[0075] 2. Mix the plasma-treated medium-modulus T700 carbon fiber, basalt fiber, glass fiber and dispersant according to the mass ratio to obtain mixed fiber; directly rinse the mixed fiber with deionized water 3 times and dry it in a vacuum drying oven at 80℃ and 0.06MPa for 4 hours;
[0076] 3. Take silane coupling agent KH-550 and titanate coupling agent monoalkoxy type isopropyltristearate titanate, mix them, add deionized water and stir evenly, adjust the pH value to 5 with acetic acid, and prepare a 4% (w / w) composite coupling agent solution. Immerse the dried mixed fiber in it and treat it at 60℃ for 1 hour. After the reaction is completed, dry it in an oven at 110℃ for 2 hours to obtain the coupled mixed fiber.
[0077] The mass ratio of KH-550 to monoalkoxy isopropyltristearate titanate is 2:1.
[0078] 4. Feed the coupled mixed fibers into a roller carding machine, set the carding speed to 10m / min, and card to an areal density of 200g / m². 2 The fiber mesh is fed into a needle punching machine, where it is reinforced by alternating upper and lower needles, with a needle density of 100 needles / cm². 2 The needle-punching depth is 5mm to obtain a needle-punched felt blank. The needle-punched felt blank is placed in a hot air circulating oven, the wind speed is set to 1m / s, and it is preheated at 120℃ for 1h. Then the temperature is raised to 180℃ and cured for 3h. Finally, it is cooled to room temperature at a rate of 5℃ / min to obtain carbon fiber needle-punched felt.
[0079] The mass ratio of medium modulus T700 polyacrylonitrile-based carbon fiber, basalt fiber, glass fiber, dispersant, and composite coupling agent is 59:18:14:2:7.
[0080] Comparative Example 2
[0081] This embodiment provides a method for preparing carbon fiber needled felt, the specific operation method including the following steps:
[0082] 1. Take medium modulus T700 polyacrylonitrile-based carbon fiber, basalt fiber, and alkali-free glass fiber, and perform plasma treatment using an argon-oxygen mixed gas volume ratio of 3:1. Set the treatment power to 80W and the vacuum degree to 0.08MPa. The treatment time is 15min for carbon fiber, 10min for basalt fiber, and 8min for alkali-free glass fiber.
[0083] 2. Mix the plasma-treated medium-modulus T700 carbon fiber, basalt fiber, glass fiber and dispersant according to the mass ratio to obtain mixed fiber; prepare a composite grafting modifier solution with a mass fraction of 12%, immerse the mixed fiber in it, react at 80℃ for 2h, rinse 3 times with deionized water after reaction, and dry in a vacuum drying oven at 80℃ and 0.06MPa for 4h to obtain modified mixed fiber;
[0084] The mass ratio of maleic anhydride, acrylic acid, and ammonium persulfate is 70:28:2.
[0085] 3. Prepare a composite coupling agent solution. Take silane coupling agent KH-550 and titanate coupling agent monoalkoxy type isopropyltristearate titanate, mix them, add deionized water and stir evenly. Adjust the pH value to 4 with acetic acid to prepare a 4% (w / w) composite coupling agent solution. Immerse the modified mixed fiber in the solution and treat it at 60℃ for 1 hour. After the reaction is completed, dry it in an oven at 110℃ for 2 hours to obtain the coupled mixed fiber.
[0086] The mass ratio of KH-550 to monoalkoxy isopropyltristearate titanate is 2:1.
[0087] 4. Feed the coupled mixed fibers into a roller carding machine, set the carding speed to 10m / min, and card to an areal density of 200g / m². 2 The fiber mesh is fed into a needle punching machine, where it is reinforced by alternating upper and lower needles, with a needle density of 100 needles / cm². 2 The needle-punching depth is 5mm to obtain a needle-punched felt blank. The needle-punched felt blank is placed in a hot air circulating oven, the wind speed is set to 1m / s, and it is preheated at 120℃ for 1h. Then the temperature is raised to 180℃ and cured for 3h. Finally, it is cooled to room temperature at a rate of 5℃ / min to obtain carbon fiber needle-punched felt.
[0088] The mass ratio of medium modulus T700 polyacrylonitrile-based carbon fiber, basalt fiber, glass fiber, composite grafting modifier, dispersant, and composite coupling agent is 49:20:15:8:6:2.
[0089] The performance test results of carbon fiber needle-punched felt are shown in Table 1.
[0090] Table 1 Performance Tests
[0091]
[0092] The study, comprising four examples and two comparative examples, confirms that this application improves the overall performance of carbon fiber needled felt by optimizing the raw material formulation and manufacturing process. Argon-oxygen mixed gas plasma treatment can physically bombard and chemically modify the surfaces of carbon fiber, basalt fiber, and alkali-free glass fiber. The high-energy particles generated by argon break the chemical bonds on the fiber surface, forming a rough structure, while oxygen introduces active groups such as hydroxyl and carboxyl groups, providing sufficient binding sites for subsequent reactions. The composite grafting modifier grafts functional groups onto the fiber surface through double bond addition and copolymerization reactions, enhancing fiber compatibility and preventing fiber aggregation. The composite coupling agent further strengthens the connection between fibers by condensing silanol groups with hydroxyl groups on the fiber surface and binding titanium oxide bonds with carboxyl groups on the fiber surface. Under the synergistic effect of these three factors, the carbon fiber needled felt exhibits excellent mechanical properties and wear resistance. The product in Example 4 has a 2D tensile strength of 35.3 MPa, a warp tensile strength of 38.2 MPa, and a wear resistance of 7200 cycles, making it suitable for various application scenarios.
[0093] Comparative Example 1, lacking the addition of a composite grafting modifier, missed the crucial step of modifying functional groups on the fiber surface and improving compatibility. This resulted in a significant weakening of the interfacial bonding between fibers, ultimately leading to a final product with an air permeability as high as 220 L / (m²). 2 The concentration of ·s is much higher than the 185 L / (m³) of Example 1. 2 The abrasion resistance of Example 1 was only 2800 cycles, and the tensile strength was less than 53% of that of Example 1. Furthermore, the fibers were prone to agglomeration, leading to poor structural stability. This demonstrates the crucial role of the composite grafting modifier in improving the interfacial bonding of the fibers. Comparative Example 2 had an excessive amount of composite grafting modifier (8 parts, exceeding the standard range of 3-5 parts) and an insufficient amount of composite coupling agent (2 parts silane coupling agent + 1 part titanate coupling agent, totaling 3 parts, below the standard range of 5-7 parts). Additionally, the pH of the composite coupling agent solution was adjusted to 4, deviating from the suitable range of 5-6, which disrupted the chemical environment for the grafting and coupling reactions, resulting in insufficient fiber surface modification. The final product had an abrasion resistance of only 3500 cycles, and the tensile strength was far lower than that of Examples 1-4. This fully demonstrates that controlling the amount of functional additives and precisely regulating the reaction environment are the core prerequisites for ensuring the performance of carbon fiber needle-punched felt.
[0094] It should be noted that the above embodiments are only used to illustrate the technical solutions of this application and are not intended to limit it. Although this application has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of this application without departing from the spirit and scope of the technical solutions of this application, and all such modifications and substitutions should be covered within the scope of the claims of this application.
Claims
1. A carbon fiber needle-punched felt, characterized in that, Including carbon fiber, basalt fiber, glass fiber, composite grafting modifier, dispersant, and composite coupling agent; The carbon fiber, basalt fiber, and alkali-free glass fiber are respectively treated with argon-oxygen mixed gas plasma. The composite grafting modifier is composed of a main grafting monomer, an auxiliary grafting monomer, and an initiator. The main grafting monomer is maleic anhydride, the auxiliary grafting monomer includes any one or more of acrylic acid, itaconic acid, and acrylamide, and the initiator includes any one of ammonium persulfate and benzoyl peroxide.
2. A carbon fiber needle-punched felt as described in claim 1, characterized in that, The mass ratio of the carbon fiber, basalt fiber, glass fiber, composite graft modifier, dispersant, and composite coupling agent is (49-65):(15-20):(10-15):(3-5):(2-4):(5-7).
3. A carbon fiber needle-punched felt as described in claim 1, characterized in that, The carbon fiber is polyacrylonitrile-based carbon fiber; the glass fiber is alkali-free glass fiber; the dispersant includes either polyethylene glycol 400 or sodium polyacrylate.
4. A carbon fiber needle-punched felt as described in claim 3, characterized in that, The composite coupling agent is composed of a silane coupling agent and a titanate coupling agent, with a mass ratio of 2-2.5:
1.
5. A carbon fiber needle-punched felt as described in claim 4, characterized in that, The silane coupling agent includes either KH-550 or KH-570; The titanate coupling agent includes either monoalkoxy isopropyltristearate titanate or di(dioctylpyrophosphoryloxy)ethylene titanate.
6. A carbon fiber needle-punched felt as described in claim 1, characterized in that, The mass ratio of the main grafting monomer, auxiliary grafting monomer and initiator in the composite grafting modifier is (68-79.5):(20-30):(0.5-2).
7. A method for preparing carbon fiber needled felt as described in claim 1, characterized in that, Including the following steps: Carbon fiber, basalt fiber, and alkali-free glass fiber were treated with argon-oxygen mixed gas plasma, with a treatment power of 80-120W, a treatment time of 15-20min for carbon fiber, 10-15min for basalt fiber, and 8-12min for glass fiber. The volume ratio of argon to oxygen was 3:1, and the vacuum degree was 0.08-0.1MPa. The carbon fiber, basalt fiber, glass fiber, and dispersant treated with argon-oxygen mixed gas plasma were mixed in a certain mass ratio to obtain a mixed fiber. The mixed fiber was then immersed in a composite grafting modifier solution and reacted at 80-90℃ for 2-3 hours. After the reaction, it was rinsed with deionized water 3-5 times and then dried in a vacuum drying oven at 80-100℃ and 0.06-0.08MPa for 4-6 hours to obtain a modified mixed fiber. The modified mixed fibers were immersed in a composite coupling agent solution and treated at 60-70℃ for 1-1.5h. After the reaction was completed, they were dried in an oven at 110-120℃ for 2-3h to obtain the coupled mixed fibers. The coupled-treated mixed fibers are fed into a carding machine at a carding speed of 10-15 m / min, and carded to a areal density of 200-300 g / m². 2 The fiber web is then fed into a needle punching machine for reinforcement, with a needle punching density of 100-300 needles / cm². 2 The needle-punching depth is 5-10mm to obtain a needle-punched felt blank; The needle-punched felt blank is placed in a hot air circulating oven with a wind speed of 1-2 m / s, preheated at 120-140℃ for 1-2 h, cured at 180-200℃ for 3-4 h, and finally cooled to room temperature at a rate of 5-10℃ / min to obtain carbon fiber needle-punched felt.
8. A method for preparing carbon fiber needled felt as described in claim 7, characterized in that... The preparation method of the composite grafting modifier solution includes slowly adding maleic anhydride to deionized water while stirring, then adding auxiliary grafting monomers and initiators in sequence, and continuing to stir for 20-25 minutes, during which the solution temperature is controlled not to exceed 35°C; the mass fraction of the composite grafting modifier solution is 12%-18%.
9. A method for preparing carbon fiber needled felt as described in claim 7, characterized in that, The preparation method of the composite coupling agent solution includes first mixing the silane coupling agent and the titanate coupling agent, then adding deionized water and stirring until uniform, and adjusting the pH value of the solution to 5-6 with acetic acid; the mass fraction of the composite coupling agent solution is 4%-6%.
10. A method for preparing carbon fiber needled felt as described in claim 7, characterized in that... The carding machine includes either a roller carding machine or a cover plate carding machine; the reinforcement method during the needle punching process is alternating puncture by upper and lower needles.