Pfa-based carbon fiber composite prepreg, and preparation method and application thereof
By modifying carbon fiber felt with plasma activation and functional slurry, combined with lamination needle punching and hot rolling processes, the problem of weak interfacial bonding between PFA resin and carbon fiber was solved, achieving efficient and uniform prepreg preparation to meet the needs of large-scale production in high-end fields.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- NANJING UNIV OF SCI & TECH
- Filing Date
- 2026-04-15
- Publication Date
- 2026-06-05
AI Technical Summary
Existing technologies struggle to achieve effective interfacial bonding between PFA resin and carbon fiber, and there is a lack of efficient and uniform continuous impregnation technologies, resulting in weak interfacial bonding and high porosity in composite materials, making it difficult to meet the large-scale production needs of high-end fields.
High-performance prepregs were prepared by using plasma activation treatment combined with functional slurry to modify carbon fiber felt, and forming a three-dimensional interpenetrating network through layered needle punching and hot rolling processes to achieve deep and uniform impregnation of PFA resin.
It significantly improves the interfacial bonding strength between PFA resin and carbon fiber, and achieves prepreg with uniform resin distribution and low porosity, which is suitable for automated manufacturing in high-end fields and reduces production costs and cycles.
Smart Images
Figure CN122143236A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of polymer composite material preparation technology, specifically relating to a PFA-based carbon fiber composite prepreg, its preparation method, and its application. Background Technology
[0002] With the rapid development of aerospace, high-end electronics, semiconductors, and specialty chemicals, there is an urgent need for structurally and functionally integrated composite materials that combine lightweight, high strength, excellent corrosion resistance, high and low temperature resistance, and stable dielectric properties. This also places higher demands on their efficient and large-scale preparation technologies. Composite materials using perfluoroalkoxy (PFA) resin as the matrix and carbon fiber as the reinforcing phase exhibit great potential in these harsh application environments due to their ability to combine the excellent chemical inertness and wide-temperature stability of PFA with the high specific strength and high specific modulus of carbon fiber. To meet the demands of mass production, developing high-quality PFA-based carbon fiber prepregs as intermediate materials is crucial.
[0003] Currently, the preparation of high-performance thermoplastic prepregs faces two major challenges: First, the interfacial bonding between resin and fiber is problematic. PFA molecular chains are highly fluorinated, with extremely low surface energy and strong chemical inertness, while carbon fiber surfaces are also inert and have high surface energy (approximately 37-48 mN / m). The thermodynamic incompatibility between the two makes it difficult for the resin melt to effectively wet and impregnate the fiber, resulting in weak interfacial bonding in the composite material. This becomes the main failure source under interlaminar shear and bending loads, and the interface becomes a performance bottleneck. Second, there is a lack of efficient and uniform continuous impregnation technology. Existing technologies such as solution impregnation require the use of large amounts of solvent, posing environmental and recycling challenges. Melt impregnation often results in insufficient wetting and high porosity due to the high viscosity of PFA melt and the tightness of fiber bundles. For example, patent CN119261333A discloses a complex multi-step process of first preparing PFA micro powder containing carbon nanotubes, then coating it onto the unfolded carbon fiber and superimposing a cast film. Although this method aims to improve the interface, its process route is lengthy and involves multiple curing and layering, making it difficult to achieve efficient and low-cost continuous prepreg production. Moreover, its reinforcement is a two-dimensional structure, which has limitations in terms of anti-delamination and adaptability to complex shapes.
[0004] Therefore, there is an urgent need to develop a new technology that can fundamentally improve the interfacial bonding between PFA and carbon fiber and achieve efficient, high-quality, and continuous production of prepregs. This technology needs to be able to deeply and uniformly activate the surface of carbon fibers and force and rapidly press PFA resin into the fiber network in a molten state. While achieving excellent wetting, it should form a stable prepreg roll suitable for subsequent automated manufacturing, thereby breaking through the bottleneck of large-scale manufacturing of high-performance PFA composite materials from materials to components. Summary of the Invention
[0005] This invention provides a PFA-based carbon fiber composite prepreg, its preparation method, and its application. It can solve the inherent problems of insufficient wetting of the three-dimensional carbon fiber network by PFA melt and weak interfacial bonding. It achieves forced, rapid, and uniform wetting of the fiber by the resin. The prepared prepreg has the characteristics of uniform resin distribution, excellent interfacial bonding, and low porosity.
[0006] To achieve the above objectives, the present invention adopts the following technical solution: A method for preparing a PFA-based carbon fiber composite prepreg includes the following steps: Surface modification treatment: The carbon fiber felt is synergistically modified by first performing plasma activation treatment, then impregnating it in a specific functional slurry and drying it. A reinforced interface layer that interacts strongly with PFA resin and even chemically bonds is constructed on the carbon fiber surface to obtain modified carbon fiber felt with PFA resin loaded on the surface. Laminated needle punching: After the modified carbon fiber felt is cut, it is alternately stacked with PFA resin film according to the predetermined weight and layup order and needle punched to form a composite laminated preform with a three-dimensional interpenetrating network. Programmed rolling: The obtained composite laminate preform is preheated and continuously hot rolled at a preset temperature and pressure, so that the PFA resin film melts and flows under the action of heat and mechanical pressure, and is forced to impregnate into the three-dimensional network of modified carbon fiber felt. After cooling and shaping, the prepreg is obtained.
[0007] In the steps described above, the parameters for plasma treatment are set as follows: oxygen, dry air or argon atmosphere, 30 Pa, 200 W, treatment time 3 minutes.
[0008] The carbon fiber felt was needle-punched before impregnation.
[0009] The soaking time is 10-30 minutes, and the drying temperature is 120℃-200℃ for 1-2 hours; In the layered needle punching treatment, the needle density is 10-30 needles / cm², and the needle depth is 5-15mm.
[0010] The functional slurry is an organic solvent dispersion of PFA resin with a solid content of 5%-20% or a fluorinated silane coupling agent with a concentration of 0.05~0.10 mg / mL.
[0011] The melt flow index and thickness of the PFA resin film can be selected according to the performance requirements of the final board.
[0012] Before rolling, the composite laminate preform is placed in the cavity of a special plate mold. A polyetherimide (PEI) release film is covered on the upper and lower surfaces of the laminate. After applying a release agent to the surface of the mold cavity, the mold is sealed.
[0013] The preheating process is as follows: the temperature of the first pair of rolls is 300℃-320℃, the pressure is 1-2MPa, and the linear speed is 1.0-1.5m / min.
[0014] The continuous hot rolling process is as follows: the temperature of the second pair of rolls is 320℃-360℃, the pressure is 3-5MPa, and the linear speed is 1.0-1.5m / min.
[0015] The cooling process is as follows: the water is cooled to 65℃-60℃ by circulating water cooling rollers at 20℃-25℃.
[0016] The winding process is as follows: the linear speed is synchronously set to 1.0-1.5 m / min, closed-loop tension feedback control is adopted, and after passing through a 3-meter-long air cooling section, the winding temperature is approximately 55℃-45℃.
[0017] The PFA-based carbon fiber composite prepreg prepared above is a composite laminate preform with a three-dimensional interpenetrating network formed by hot rolling, using activated and modified carbon fiber felt as the reinforcing skeleton and PFA resin film as the matrix.
[0018] The above-mentioned PFA-based carbon fiber composite prepreg can be used to prepare PFA-based carbon fiber composite sheets.
[0019] Beneficial effects: This invention provides a PFA-based carbon fiber composite prepreg, its preparation method, and its application, which have the following advantages compared with the prior art: (1) The present invention adopts a synergistic activation modification strategy of "plasma-functional slurry", which has a simple and efficient processing flow, significantly improves the interfacial bonding strength between PFA resin and carbon fiber, and achieves full impregnation of carbon fiber by resin using rolling process, fundamentally solving the bottleneck of mechanical properties of composite materials; moreover, the surface modification strategy and prepreg composite molding process are simple, mild and continuous, and the modification process does not require complex high-temperature chemical treatment. The rolling molding completes melting, impregnation and composite in a single process. The whole process is solvent-free and does not require multi-step curing. The process is simple, green and easy to integrate and scale up.
[0020] (2) The present invention uses activated modified carbon fiber felt as reinforcement and PFA resin as matrix. It is laid and needled according to a predetermined laminate structure. The structural advantage of the interlocking of internal fiber and resin network significantly improves the interlayer performance and anti-delamination ability of the composite material.
[0021] (3) This invention integrates surface modification, stacking needle punching and rolling processes to form a short-process integrated molding technology, realizing a complete continuous production from fiber surface activation and slurry modification pretreatment to stacking needle punching with PFA film, hot rolling, cooling and winding. Surface treatment can be completed online or near-line, and it can be efficiently connected with the rolling process to form a complete prepreg production line, which significantly improves production efficiency and is suitable for large-scale, standardized manufacturing.
[0022] (4) The process design (modification-needle punching-rolling) of the present invention can achieve precise and stable control of the interface structure, resin content, impregnation quality and mechanical properties of the prepreg in continuous production. The process window is wide and the control parameters are clear, which can ensure the consistency of different batches of prepreg in impregnation quality, interface bonding and physical properties, and meet the strict requirements of high-end fields for material uniformity.
[0023] (5) The prepreg prepared by the present invention has a strong internal interface bond, uniform resin distribution, and low porosity. It has both excellent interface performance and good process applicability. It can be directly used for subsequent automated lay-up and molding, which greatly shortens the manufacturing cycle of composite material products and reduces the overall cost. It provides a feasible material solution for the large-scale and low-cost application of PFA-based high-performance composite materials in semiconductor equipment, aerospace and other fields. Attached Figure Description
[0024] Figure 1 This is a photograph of the PFA-based carbon fiber material after needle punching in Embodiment 1 of the present invention; Figure 2 This is a schematic diagram of the stacked structure of modified carbon fiber and PFA resin in Embodiment 1 of the present invention; Figure 3 This is a photograph of the prepreg after rolling in Embodiment 1 of the present invention. Detailed Implementation
[0025] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments: Example 1
[0026] A PFA-based carbon fiber composite prepreg and its preparation method, specifically including the following steps: The needle-punched carbon fiber felt was placed in a low-pressure radio frequency plasma treatment machine, evacuated to a pressure of 30 Pa, and treated with oxygen, dry air, or argon. The discharge power was set to 200 W, and the treatment time was 3-5 minutes to complete the surface activation of the fibers. Subsequently, it was impregnated in an organic solvent dispersion of PFA resin for 10-30 minutes, and dried at 120℃-200℃ for 1-2 hours to obtain surface-modified carbon fiber felt.
[0027] The modified carbon fiber felt and the two layers of PFA resin film were needle-punched using a process with a needle-punching density of 10-30 needles / cm² and a needle-punching depth of 5-15mm. Figure 1 As shown, the layers are then simultaneously unwound and precisely stacked via a guide roller system to form a sandwich structure of "PFA film-modified felt-PFA film", as shown below. Figure 2 As shown, the film is continuously fed into the hot rolling mill. First, it undergoes preliminary treatment in the preheating roll zone, with a roll surface temperature of 300°C-320°C and a pressure of 1-2 MPa, softening and initially compacting the film. Then, it enters the main rolling zone, where the roll temperature rises to 320°C-360°C and the pressure increases to 3-5 MPa. Under these conditions, the PFA resin completely melts and is forced and rapidly impregnated into the three-dimensional network of the modified carbon fiber felt under high pressure, achieving deep and uniform wetting. The production line speed is maintained at 1.0-1.5 m / min.
[0028] The fully impregnated prepreg tape is immediately cooled and cured rapidly by cooling rollers (surface temperature 20℃-25℃), and then guided by a tension control system to be wound into a prepreg roll under constant tension. The resulting prepreg roll has uniform resin distribution, complete fiber impregnation, and strong interfacial bonding, such as... Figure 3 As shown, it can be directly used for subsequent molding or hot pressing to prepare composite sheets.
[0029] Comparative Example 1 The preparation method of the PFA-based carbon fiber composite prepreg in this comparative example differs from that in Example 1 in that the PFA-based carbon fiber composite prepreg does not include a plasma treatment step.
[0030] Comparative Example 2 The preparation method of the PFA-based carbon fiber composite prepreg in this comparative example differs from that in Example 1 in that the PFA-based carbon fiber composite prepreg does not have a functional slurry impregnation treatment step.
[0031] Comparative Example 3 The preparation method of the PFA-based carbon fiber composite prepreg in this comparative example differs from that in Example 1 in that the PFA-based carbon fiber composite prepreg does not include the needle punching treatment step.
[0032] The tensile strength and flexural strength of the PFA-based carbon fiber composite prepregs prepared in the examples and comparative examples were tested after hot pressing, and the results are shown in Table 1.
[0033] The tensile test was conducted according to GB / T 1040.1-2018, and the bending test was conducted according to GB / T 9341-2008. The specific testing method is as follows: Select samples and set the sample size according to GB / T 1040.1-2018 and GB / T 9341-2008 above; The tensile and bending specimens are mounted in the fixture, and the zero point of the universal testing machine is adjusted. The loading speed was set to 2 mm / min, and the load was applied uniformly and continuously until failure was achieved. The failure load value was then recorded. The average value was taken after 5 tests.
[0034] Table 1. Tensile and flexural strengths of composite prepregs in the examples and comparative examples. Group <![CDATA[Density (g / cm 3 ).]]> Bending strength (MPa) Tensile strength (MPa) Example 1 2.10 177.950 211.198 Comparative Example 1 2.04 142.423 198.433 Comparative Example 2 1.97 132.353 186.871 Comparative Example 3 2.01 139.818 192.714 Table 1 shows that the PFA-based carbon fiber composite prepreg prepared in Example 1 has a density of 2.10 g / cm³, a flexural strength of 177.950 MPa, and a tensile strength of 211.198 MPa. The test results from the above examples and comparative examples show that each parameter has a significant impact on the material's density, flexural strength, and tensile strength. Among these, the synergistic activation modification using plasma-functional slurry is a key factor in improving overall performance, effectively enhancing interfacial bonding and improving the material's mechanical properties. In summary, the prepreg obtained by using synergistic activation modification with plasma-functional slurry and needle-punching treatment of carbon fiber felt and PFA resin film exhibits strong internal interfacial bonding, uniform resin distribution, and low porosity.
[0035] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.
Claims
1. A method for preparing a PFA-based carbon fiber composite prepreg, characterized in that, Includes the following steps: Surface synergistic modification treatment: The carbon fiber felt is first subjected to plasma activation treatment, then impregnated in functional slurry and dried to construct a reinforced interface layer on the carbon fiber surface that interacts strongly with PFA resin and even chemically bonds with it. Lamination needle punching treatment: The modified carbon fiber felt and PFA resin film are alternately stacked according to the predetermined basis weight and layup order and needle punched to form a composite laminated preform with a three-dimensional interpenetrating network. Programmed rolling: The obtained composite laminate preform is preheated and continuously hot rolled at a preset temperature and pressure, so that the PFA resin film melts and flows under the action of heat and mechanical pressure, and is forced to impregnate into the three-dimensional network of modified carbon fiber felt. After cooling and shaping, the composite prepreg is obtained.
2. The method for preparing PFA-based carbon fiber composite prepreg according to claim 1, characterized in that, The carbon fiber felt was needle-punched before impregnation.
3. The method for preparing PFA-based carbon fiber composite prepreg according to claim 1 or 2, characterized in that, The functional slurry is an organic solvent dispersion of PFA resin with a solid content of 5%-20% or a fluorinated silane coupling agent with a concentration of 0.05%-0.10%.
4. The method for preparing PFA-based carbon fiber composite prepreg according to claim 3, characterized in that, The melt flow index and thickness of the PFA resin film can be selected according to the performance requirements of the final board.
5. The method for preparing PFA-based carbon fiber composite prepreg according to claim 1, characterized in that, In the layered needle punching treatment, the needle density is 10-30 needles / cm², and the needle depth is 5-15mm.
6. The method for preparing PFA-based carbon fiber composite prepreg according to claim 1, characterized in that, The preheating process in programmed rolling is as follows: the temperature of the first pair of rolls is 300℃-320℃, the pressure is 1-2MPa, and the linear speed is 1.0-1.5m / min.
7. The method for preparing PFA-based carbon fiber composite prepreg according to claim 1 or 6, characterized in that, The continuous hot rolling process in programmed rolling is as follows: the temperature of the second pair of rolls is 320℃-360℃, the pressure is 3-5MPa, and the linear speed is 1.0-1.5m / min.
8. The method for preparing PFA-based carbon fiber composite prepreg according to claim 1, characterized in that, The cooling process in programmed rolling is as follows: the temperature is cooled to 65℃-60℃ by circulating water cooling rollers at 20℃-25℃; the winding process is as follows: the linear speed is synchronously set to 1.0-1.5 m / min, closed-loop tension feedback control is adopted, and after passing through a 3-meter-long air cooling section, the winding temperature is approximately 55℃-45℃.
9. The PFA-based carbon fiber composite prepreg prepared by the method according to any one of claims 1-8, characterized in that, The composite laminate preform with a three-dimensional interpenetrating network, formed by hot rolling, uses activated and modified carbon fiber felt as the reinforcing skeleton and PFA resin film as the matrix.
10. The application of the PFA-based carbon fiber composite prepreg according to claim 9, characterized in that, The composite prepreg is used for molding or hot pressing composite sheets.