A polydicyclopentadiene carbon fiber composite material and its preparation method

Abstract

This invention discloses a polydicyclopentadiene carbon fiber composite material and its preparation method, belonging to the field of composite material technology. Based on the steps of preparing carbon fiber felt, polydicyclopentadiene resin, carbon fiber reinforcement, and polydicyclopentadiene carbon fiber composite material, this invention proposes a method for preparing novel carbon fiber composite materials by combining multi-stage hot roll pre-pressing with vacuum infusion molding. The material, during preparation, simultaneously possesses the resin uniformity of vacuum infusion molding and the compactness of roll pressing, making it suitable for preparing composite materials using resins with high viscosity, poor flowability, and a tendency to generate bubbles during vacuum infusion as the base material. This method can effectively simplify the process, reduce costs, and produce advanced carbon fiber reinforced composite materials with high product quality stability and a low number of internal material defects.

Description

Technical Field

[0001] This invention relates to the field of composite material technology, and in particular to a polydicyclopentadiene carbon fiber composite material and its preparation method. Background Technology

[0002] Lightweight materials significantly improve energy efficiency (such as reducing fuel consumption and extending battery life) and enhance mechanical properties (such as strength and durability) by reducing product weight. They also drive low-carbon emission reduction in fields such as automotive, aerospace, and new energy, making them a crucial technological pillar for industrial upgrading and sustainable development. Existing lightweight materials mainly include carbon fiber composites, aluminum alloys, magnesium alloys, titanium alloys, glass fiber reinforced composites, engineering plastics, foamed metals, and ceramic materials.

[0003] Carbon fiber composites with carbon fiber reinforcement have received widespread attention and application, but their further development and application are limited by the inherent brittleness of epoxy resin and the long molding time required. Similarly, aluminum alloys have low strength, poor high-temperature resistance, and are difficult to weld; magnesium alloys have poor corrosion resistance, weak high-temperature performance, and high processing costs; titanium alloys are extremely expensive, difficult to process, and have high density; glass fiber reinforced composites are expensive, exhibit anisotropy, and are difficult to recycle; engineering plastics such as PA have poor temperature resistance and weak creep resistance, and also pose environmental problems; foamed metals have extremely low strength, poor production consistency, and high costs; ceramic materials such as silicon carbide and alumina are brittle, difficult to process, and also have reliability issues. Based on these shortcomings, proposing a new type of lightweight composite material has become a technical problem that urgently needs to be solved in the current technology. Summary of the Invention

[0004] Based on the technical problems to be solved by the present invention, the present invention adopts a combination of multi-stage hot roller pre-pressing and vacuum injection molding to prepare a novel carbon fiber composite material, and proposes a polydicyclopentadiene carbon fiber composite material and its preparation method.

[0005] One objective of this invention is to provide a method for preparing polydicyclopentadiene carbon fiber composite material, comprising: S1, cutting carbon fibers and resin fibers, and wet-blending the cut short carbon fibers and resin fibers to obtain carbon fiber felt; S2, purifying dicyclopentadiene to over 95%, adding a dicyclopentadiene polymerization catalyst, inhibitor, and stabilizer, and mixing evenly to obtain a dicyclopentadiene resin mixture; S3, placing a mold containing the carbon fiber felt into a heated roller pressing device for pre-rolling to obtain a material with improved structural stability. S4. Cool the structurally enhanced carbon fiber felt and transfer it into the mold for vacuum injection molding. Vacuum is drawn, and the material is compacted under atmospheric pressure to obtain a carbon fiber felt with secondary enhanced stability. S5. Under the action of air pressure, the dicyclopentadiene resin mixture is drawn into the mold to impregnate the carbon fiber felt with secondary enhanced stability. The mold is then transferred back to the rolling equipment to perform secondary rolling on the carbon fiber felt with secondary enhanced stability to obtain a polydicyclopentadiene carbon fiber composite material.

[0006] Further, the step of cutting carbon fibers and resin fibers, and wet-blending the cut chopped carbon fibers and resin fibers to obtain carbon fiber felt includes: S11, cutting continuous carbon fiber bundles into lengths of 1-10cm to obtain 1-1000g of chopped carbon fibers; S12, weighing a small amount of resin fibers and cutting them to obtain 1-1000g of chopped resin fibers; S13, wet-blending the cut chopped carbon fibers and resin fibers to obtain carbon fiber felt.

[0007] Further, the purification of dicyclopentadiene to over 95%, the addition of a dicyclopentadiene polymerization catalyst, an inhibitor, and a stabilizer, and the uniform mixing to obtain a dicyclopentadiene resin mixture, includes: S21, purifying dicyclopentadiene by vacuum distillation to obtain dicyclopentadiene with a purity of over 95%; S22, adding 0.5~2 wt% of dicyclopentadiene polymerization catalyst, 0.5~2 wt% of inhibitor, and 0.5~2 wt% of stabilizer to the dicyclopentadiene with a purity of over 95%, and mixing uniformly to obtain a dicyclopentadiene resin mixture.

[0008] Further, the step of placing the mold containing the carbon fiber felt into a heated roller pressing device for pre-rolling to obtain carbon fiber felt with enhanced structural stability includes: S31, laying the carbon fiber felt flat on the mold, placing the mold flat in a heated roller pressing device for pre-rolling to make the carbon fiber felt flat; S32, by adjusting the temperature of the roller pressing device, performing hot-melt bonding on the carbon fiber felt to obtain carbon fiber felt with enhanced structural stability.

[0009] Further, the step of cooling the structurally stable carbon fiber felt, transferring it into the vacuum-casting mold, evacuating the vacuum, and compacting it under atmospheric pressure to obtain a carbon fiber felt with secondary stability enhancement includes: S41, cooling the structurally stable carbon fiber felt, transferring it into the vacuum-casting mold, and laying the structurally stable carbon fiber felt flat; S42, sealing the vacuum bag, placing and fixing the resin guide tube to ensure that the dicyclopentadiene resin mixture can uniformly and fully impregnate the structurally stable carbon fiber felt; S43, evacuating the vacuum to create an internal vacuum in the structurally stable carbon fiber, obtaining a carbon fiber felt with internal vacuum; S44, compacting the internally vacuum carbon fiber felt under atmospheric pressure to obtain a carbon fiber felt with secondary stability enhancement.

[0010] Further, the step of drawing the dicyclopentadiene resin mixture into the mold under air pressure to impregnate the secondary-strengthened carbon fiber felt, and then transferring the mold back to the rolling mill to perform a second rolling of the secondary-strengthened carbon fiber felt to obtain the polydicyclopentadiene carbon fiber composite material includes: S51, opening the mold switch, drawing the dicyclopentadiene resin mixture into the mold under air pressure to impregnate the secondary-strengthened carbon fiber felt, and closing the mold switch after sufficient impregnation; S52, transferring the mold back to the rolling mill to perform a second rolling of the secondary-strengthened carbon fiber felt, using the rolling pressure to assist vacuum to remove air bubbles in the secondary-strengthened carbon fiber felt, ensuring that the dicyclopentadiene resin mixture is fully impregnated; S53, when the dicyclopentadiene resin in the secondary-strengthened carbon fiber felt is completely polymerized into polydicyclopentadiene, opening the mold, and trimming the edges of the polydicyclopentadiene carbon fiber composite material to obtain the polydicyclopentadiene carbon fiber composite material.

[0011] Furthermore, the resin fiber is a thermoplastic resin fiber; the resin fiber includes one of PA66, PA6, PP, PE, PC, PPS, and PEEK; PA66 is polyhexamethylene adipamide, a high-strength, high-wear-resistant engineering plastic; PA6 is polycaprolactam, possessing excellent mechanical properties and wear resistance; PP is polypropylene, a lightweight, high-strength thermoplastic; PE is polyethylene, a common plastic; PC is polycarbonate, possessing high transparency and excellent impact strength; PPS is polyphenylene sulfide, possessing excellent heat resistance and chemical stability; and PEEK is polyetheretherketone, a high-performance plastic with excellent high-temperature resistance and chemical corrosion resistance.

[0012] Further, the resin fibers are cut to 1-3 cm; preferably, the resin fibers are cut to 2 cm. Further, the continuous carbon fibers are cut to 4-8 cm to ensure that both the carbon fibers and resin fibers can be fully dispersed during the wet felting process, ensuring the uniformity and stability of the material.

[0013] Furthermore, the dicyclopentadiene polymerization catalyst is a ruthenium-based catalyst or a non-ruthenium catalyst; the ruthenium-based catalyst includes Grubbs catalysts. In the ring-opening metathesis polymerization (ROMP) reaction of dicyclopentadiene (DCPD), in addition to the traditional Hoveyda-Grubbs ruthenium catalyst, other types of catalyst systems can also be considered. The Hoveyda-Grubbs catalyst is an important member of the Grubbs catalyst family and is particularly suitable for the ring-opening metathesis polymerization of cyclic olefins such as DCPD.

[0014] Furthermore, the non-ruthenium catalyst includes metal carbene catalysts and non-metal catalysts. Non-ruthenium catalysts include metal carbene catalysts such as molybdenum and tungsten (e.g., Schrock catalysts) and non-metal catalysts.

[0015] Furthermore, the inhibitor is an inhibitor capable of inhibiting the ring-opening polymerization rate of dicyclopentadiene, and the inhibitor includes triphenyl phosphate, hydroquinone, and BHT (246); further, the inhibitor is an organic inhibitor, and the inhibitor inhibits the ring-opening polymerization rate of DCPD, thereby avoiding the explosive polymerization of DCPD.

[0016] Furthermore, when the carbon fiber felt is rolled, the roller temperature is increased by 10~20°C based on the melting point of the resin fiber; preferably, the temperature is increased by 15°C to ensure that the resin can be melted quickly, thus ensuring the efficiency and continuity of material processing.

[0017] Furthermore, the vacuum level should reach 2 Pa to ensure that the felt material is free of air bubbles.

[0018] This method addresses the problem of material performance degradation caused by air bubbles generated during the curing process of polydicyclopentadiene impregnating carbon fibers. It proposes pre-compressing and fixing the carbon fiber felt before impregnation to ensure fiber structural stability. Furthermore, by applying external force during the curing stage, air bubbles generated during curing are effectively eliminated, ensuring the reliability of material performance.

[0019] The second objective of this invention is to provide a polydicyclopentadiene carbon fiber composite material, which is prepared by a method for preparing polydicyclopentadiene carbon fiber composite materials.

[0020] Furthermore, the porosity of the polydicyclopentadiene carbon fiber composite material is below 0.3%. This material is a polydicyclopentadiene / carbon fiber composite material, which possesses excellent corrosion resistance, heat resistance, and mechanical properties, while also featuring low preparation cost and high production efficiency. Furthermore, the high stability of polydicyclopentadiene effectively compensates for the shortcomings of metallic materials in terms of heat resistance and corrosion resistance. Furthermore, based on the excellent mechanical properties and low cost of polydicyclopentadiene, it overcomes the difficulties in achieving both high mechanical properties and high temperature resistance in engineering plastics, as well as the insufficient toughness of ceramic materials. Furthermore, the easy processing characteristics of polydicyclopentadiene avoid the drawbacks of traditional metallic materials requiring complex processes to achieve high performance.

[0021] Compared with the prior art, the present invention proposes a polydicyclopentadiene carbon fiber composite material and its preparation method, which has the following beneficial effects: The polydicyclopentadiene carbon fiber composite material proposed in this invention achieves optimized structural stability of the carbon fiber reinforcement. This invention employs roller preheating and pre-pressing treatment of the carbon fiber felt, enabling preliminary bonding between fibers before resin impregnation, thereby significantly improving the overall structural stability of the material. The preheated fiber felt forms a stable three-dimensional network structure, exhibiting excellent deformation resistance and effectively resisting the damage to the material structure during resin flow.

[0022] Furthermore, this invention optimizes the multi-stage roller pressing assisted impregnation process. The invention employs a multi-stage roller pressing process, performing a secondary roller pressing treatment immediately after resin infusion, using controllable mechanical pressure to assist in the removal of air bubbles. This process can significantly reduce the internal porosity of the material, resulting in a substantial improvement in product performance. Attached Figure Description

[0023] Figure 1 A flowchart illustrating the preparation process of a polydicyclopentadiene carbon fiber composite material according to an embodiment of the present invention is shown.

[0024] Figure 2 The images show physical photos (from left to right) of the three polydicyclopentadiene carbon fiber composite materials prepared in Examples 1, 2, and 3 of this invention. Detailed Implementation

[0025] Exemplary embodiments of the present application will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present application are shown in the drawings, it should be understood that the present application may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this application will be thorough and complete, and will fully convey the scope of the present application to those skilled in the art.

[0026] Unless otherwise specified, the technical means used in the following embodiments are conventional means well known to those skilled in the art, and the reagents and materials in this invention are obtained from the market or other public channels.

[0027] The experimental materials and equipment involved in this invention mainly include, but are not limited to: Reagents: Dicyclopentadiene, 95% purity, containing 100-200 ppm stabilizer; 4-tert-butylcatechol, China National Pharmaceutical Group Chemical Reagent Co., Ltd.; Grubbs 2nd generation catalyst, 98% purity, China National Pharmaceutical Group Chemical Reagent Co., Ltd.; Norbornene, 99% purity, China National Pharmaceutical Group Chemical Reagent Co., Ltd.; Triphenyl phosphate, ≥99.8% purity, Shanghai Maclean Biological Reagent Co., Ltd.; Hydroquinone, 99% purity, Shanghai Maclean Biological Reagent Co., Ltd.; Carbon fiber, 25K, Jilin Chemical Fiber Group; PP, Shenzhen Teli New Material Technology Co., Ltd.; PA66, Shenzhen Teli New Material Technology Co., Ltd.; PE, Shenzhen Teli New Material Technology Co., Ltd.

[0028] The present invention discloses a polydicyclopentadiene carbon fiber composite material and its preparation method. The main technical principles include: The polydicyclopentadiene carbon fiber composite material of this invention uses a felt made from chopped carbon fibers as the fiber reinforcement and PDCPD as the reinforcing resin. The preparation method is a novel approach combining multi-stage hot roller pre-pressing and vacuum infusion molding. In this invention, the carbon fiber felt is pre-heated and pre-pressed before resin impregnation, causing the fibers within the felt to bond together with the resin, significantly improving the material's structural stability. Due to the flow resistance of the resin during impregnation, when untreated carbon fiber felt is impregnated, adjacent carbon fibers lack stable connections, making them prone to agglomeration as the resin flows. Therefore, the hot-pressed fiber felt possesses good deformation resistance, effectively counteracting the damage to the felt structure caused by resin flow, resulting in good structural stability of the carbon fiber reinforcement. However, after vacuum resin infusion, the PDCPD material generates numerous air bubbles during infusion. As the polymerization reaction progresses, the cross-linking degree of the PDCPD material gradually increases, leading to a significant increase in viscosity. Consequently, the air bubbles within the material are difficult to remove effectively, resulting in defects and negatively impacting product performance. Therefore, multi-stage roller pressing assisted resin impregnation involves using roller pressing equipment to perform secondary roller pressing on the material after injection, applying auxiliary force through mechanical means to remove air bubbles. This method can greatly avoid the presence of air bubbles, thereby significantly improving the performance of the material.

[0029] Based on the above principles, this invention proposes a polydicyclopentadiene carbon fiber composite material and its preparation method. This method can effectively simplify the process, reduce costs, and produce advanced carbon fiber reinforced composite materials with high product quality stability and low internal material defects. The specific technical solution includes: (1) Preparation of carbon fiber felt First, continuous carbon fiber bundles are cut into lengths of 1-10 cm to obtain an appropriate amount of chopped carbon fibers. Then, a small amount of resin fibers is weighed and cut to obtain 1-100 g of chopped resin fibers. Next, the cut chopped carbon fibers and chopped resin fibers are mixed using a wet-process felting technique to prepare carbon fiber felt.

[0030] (2) Preparation of polydicyclopentadiene resin First, dicyclopentadiene (DCPD) was purified to over 99% using vacuum distillation. Then, 0.5–2 wt% of Grubbs catalyst, 0.5–2 wt% of inhibitor, and 0.5–2 wt% of stabilizer were weighed out.

[0031] (3) Preparation of carbon fiber reinforcement First, the carbon fiber felt prepared in step (1) is laid flat on the mold. Then, the mold is placed flat in a heated roller pressing device for pre-rolling to flatten the felt. Next, by adjusting the temperature of the roller pressing device, the carbon fiber felt is preliminarily heat-fused to give it a certain resistance to deformation and improve its structural stability in subsequent processing.

[0032] (4) Preparation of composite materials The cooled carbon fiber felt was transferred to a vacuum casting mold, ensuring the felt was laid flat. Then, the vacuum bag was sealed, and a resin guide tube was placed to ensure the resin could evenly and fully impregnate the felt. Next, a vacuuming operation was performed to ensure a vacuum inside the felt, and atmospheric pressure was used to compact the felt, further improving its structural stability. Then, the PDCD, Grubbs catalyst, inhibitor, and stabilizer from step (2) were mixed evenly in a beaker, and the switch was turned on so that the mixed resin solution in the beaker was drawn into the mold under air pressure to impregnate the felt. Then, after the entire felt was fully impregnated, the switch was turned off, and the mold was transferred back to the rolling mill for a second rolling process. The rolling pressure assisted in vacuuming to remove air bubbles from the felt, ensuring sufficient resin impregnation inside. Finally, after the DCPD inside the felt was completely polymerized into PDCPD, the mold was opened and the material edges were trimmed, thus preparing the polydicyclopentadiene carbon fiber composite material.

[0033] In existing technologies, polydicyclopentadiene (PDCPD) exhibits superior impact resistance and toughness due to its significantly higher elongation at break (>20%) compared to epoxy resins (typically <5%), making it less prone to brittle cracking under dynamic loads (such as collisions and drops). Simultaneously, PDCPD's highly cross-linked network structure effectively inhibits crack propagation, making it suitable for applications requiring fatigue resistance (such as automotive anti-collision components). Furthermore, because PDCPD undergoes ring-opening displacement polymerization (POMP) during molding, it can be cured within minutes to tens of minutes without requiring high-temperature catalytic curing. Compared to the curing time (hours) and high-temperature (120℃~180℃) molding conditions of epoxy resins, PDCPD offers significant advantages in reducing energy consumption and improving production efficiency. However, the application of PDCPD materials is limited by its slightly lower mechanical properties compared to epoxy resins and the need for suitable molding processes. Currently, the main molding process for PDCPD (Polycarbon Dioxide Carbon Fiber) is reaction injection molding. In this process, pre-mixed resin is injected into a pre-fabricated fiber reinforcement under high pressure using an injection molding machine to prepare carbon fiber composites. However, because the resin flow during injection relies primarily on the injection thrust generated by the equipment, the pressure is often concentrated in one area. This easily leads to fiber rearrangement and agglomeration in chopped carbon fiber felt. This phenomenon severely compromises the uniformity and stability of the carbon fiber reinforcement structure, causing the composite material, which should be isotropic, to exhibit anisotropy. Furthermore, air bubbles may be generated as the resin passes through the injection port. If these bubbles are not eliminated during curing, they will form internal voids, significantly reducing the mechanical properties of the composite material.

[0034] This invention employs a method combining multi-stage hot roller pre-pressing with vacuum injection molding to prepare a high-performance polydicyclopentadiene carbon fiber composite material. This gives it broader application prospects and performance potential.

[0035] Example 1 This invention proposes a method for preparing polydicyclopentadiene carbon fiber composite material.

[0036] Mainly includes: (1) Cut the continuous carbon fiber to 4cm and cut the PA66 fiber to 2.5cm. Weigh the two fibers after cutting according to the mass ratio of carbon fiber to PA66 fiber of 9:1.

[0037] (2) Put the cut carbon fiber into the water tank and turn on the ultrasonic device to disperse it. After the carbon fiber is completely dispersed in the water, add PA66 fiber and stir thoroughly until the two fibers are evenly mixed in the water and the fiber clumps turn grayish-white.

[0038] (3) The well-dispersed mixed fibers are filtered through a filter screen to remove excess water, and then plasticized in a mold frame to obtain a carbon fiber / PA66 mixed wet felt with a certain shape.

[0039] (4) Transfer the mixed wet felt in the mold to the metal mesh, and place the metal mesh in an oven at 70°C. After drying for 10 hours, the mixed felt is obtained.

[0040] (5) Transfer the dried mixed felt into the vacuum-assisted injection mold and ensure that the felt is laid flat.

[0041] (6) After the felt material is laid out, resin guide tubes, guide nets and release cloth are laid in the mold. After the laying is completed, the entire mold is sealed with high temperature resistant sealing tape on the outer ring of the mold.

[0042] (7) Place the mold in the roller press and set the roller to 280°C. Then turn on the roller press to perform preliminary roller pressing on the felt material in the mold, so that the internal resin melts and the carbon fiber mesh structure is bonded and fixed.

[0043] (8) The DCPD is purified by vacuum distillation to remove impurities and achieve a purity of over 99%.

[0044] (9) Weigh the purified DCPD, Grubbs catalyst and triphenyl phosphate respectively, in a mass ratio of 98:1.5:0.5.

[0045] (10) Mix the three components thoroughly in a beaker and perform vacuum defoaming treatment to prevent air bubbles from being sucked into the felt.

[0046] (11) Place the mixed resin solution after vacuum defoaming into the guide port. After the vacuum degree in the mold reaches 2Pa, open the guide port valve so that the resin solution is sucked into the mold to impregnate the felt material.

[0047] (12) After the resin has completely impregnated the felt, close the guide valve to stop the resin intake and keep the vacuum in the mold at 2 Pa.

[0048] (13) Place the mold back into the roller press and roll it repeatedly at 80°C 5 times until there are no obvious air bubbles in the felt material.

[0049] (14) Then transfer the mold to the curing oven and cure at 80°C for 20 minutes.

[0050] (15) After complete curing, open the sealing film, take out the composite material and trim it to obtain polydicyclopentadiene carbon fiber composite material.

[0051] result: Please see Figure 1 and Figure 2 Tests showed that the CF / PA66 / PDCPD composite material possesses good mechanical properties, with a tensile strength of 240.8 MPa, a flexural strength of 412.9 MPa, and an impact strength of 115.1 MPa. The polymerization rate of DCPD was effectively controlled by adding a small amount of polymerization inhibitor (0.5 wt% triphenyl phosphate), thus avoiding the explosive polymerization phenomenon of DCPD.

[0052] Example 2 This invention proposes another method for preparing polydicyclopentadiene carbon fiber composite materials.

[0053] Mainly includes: (1) Cut the continuous carbon fiber to 6cm and the PP fiber to 2.5cm. Weigh the two fibers after cutting according to the mass ratio of carbon fiber to PP fiber of 8:2.

[0054] (2) Put the cut carbon fiber into the water tank and turn on the ultrasonic device to disperse it. After the carbon fiber is completely dispersed in the water, add PP fiber and stir thoroughly until the two fibers are evenly mixed in the water and the fiber clumps turn grayish-white.

[0055] (3) The well-dispersed mixed fibers are filtered through a filter screen to remove excess water, and then plasticized in a mold frame to obtain a carbon fiber / PP mixed wet felt with a certain shape.

[0056] (4) Transfer the mixed wet felt in the mold to the metal mesh, and place the metal mesh in an oven at 70°C. After drying for 10 hours, the mixed felt is obtained.

[0057] (5) Transfer the dried mixed felt into the vacuum-assisted injection mold and ensure that the felt is laid flat.

[0058] (6) After the felt material is laid out, resin guide tubes, guide nets and release cloth are laid in the mold. After the laying is completed, the entire mold is sealed with high temperature resistant sealing tape on the outer ring of the mold.

[0059] (7) Place the mold in the roller press and set the roller to 180°C. Then turn on the roller press to perform preliminary roller pressing on the felt material in the mold, so that the internal resin melts and the carbon fiber mesh structure is bonded and fixed.

[0060] (8) The DCPD is purified by vacuum distillation to remove impurities and achieve a purity of over 99%.

[0061] (9) Weigh the purified DCPD, Grubbs catalyst and hydroquinone respectively, in a mass ratio of 97:1.5:1.5.

[0062] (10) Mix the three components thoroughly in a beaker and perform vacuum defoaming treatment to prevent air bubbles from being sucked into the felt.

[0063] (11) Place the mixed resin solution after vacuum defoaming into the guide port. After the vacuum degree in the mold reaches 2Pa, open the guide port valve so that the resin solution is sucked into the mold to impregnate the felt material.

[0064] (12) After the resin has completely impregnated the felt, close the guide valve to stop the resin intake and keep the vacuum in the mold at 2 Pa.

[0065] (13) Place the mold back into the roller press and roll it repeatedly at 80°C 5 times until there are no obvious air bubbles in the felt material.

[0066] (14) Then transfer the mold to the curing oven and cure at 80°C for 20 minutes.

[0067] (15) After complete curing, open the sealing film, take out the composite material and trim it to obtain polydicyclopentadiene carbon fiber composite material.

[0068] result: Please see Figure 1 and Figure 2 Testing revealed that the CF / PP / PDCPD composite material exhibits good mechanical properties, with a tensile strength of 201.2 MPa, a flexural strength of 390.4 MPa, and an impact strength of 111.9 MPa. By further increasing the amount of polymerization inhibitor (1.5 wt% hydroquinone), the polymerization rate of DCPD was effectively controlled, thus avoiding DCPD burst polymerization. Furthermore, by selecting longer carbon fibers to prepare carbon fiber mats, it was found that although PP material was chosen as the resin matrix, the overall strength of the composite material was only slightly lower than that of the CF / PA66 / PDCPD composite material, indicating that increasing the length of the carbon fibers can effectively control the performance.

[0069] Example 3 This invention proposes another method for preparing polydicyclopentadiene carbon fiber composite materials.

[0070] Mainly includes: (1) Cut the continuous carbon fiber to 1cm and cut the UHMWPE fiber to 1cm. Weigh the two fibers after cutting according to the mass ratio of carbon fiber to UHMWPE fiber of 9:1.

[0071] (2) Put the cut carbon fiber into the water tank and turn on the ultrasonic device to disperse it. After the carbon fiber is completely dispersed in the water, add UHMWPE fiber and stir it thoroughly until the two fibers are evenly mixed in the water and the fiber clumps turn grayish-white.

[0072] (3) The well-dispersed mixed fibers are filtered through a filter screen to remove excess water, and then plasticized in a mold frame to obtain a carbon fiber / UHMWPE mixed wet felt with a certain shape.

[0073] (4) Transfer the mixed wet felt in the mold to the metal mesh, and place the metal mesh in an oven at 70°C. After drying for 10 hours, the mixed felt is obtained.

[0074] (5) Transfer the dried mixed felt into the vacuum-assisted injection mold and ensure that the felt is laid flat.

[0075] (6) After the felt material is laid out, resin guide tubes, guide nets and release cloth are laid in the mold. After the laying is completed, the entire mold is sealed with high temperature resistant sealing tape on the outer ring of the mold.

[0076] (7) Place the mold in the roller press and set the roller to 150°C. Then turn on the roller press to perform preliminary roller pressing on the felt material in the mold, so that the internal resin melts and the carbon fiber mesh structure is bonded and fixed.

[0077] (8) The DCPD is purified by vacuum distillation to remove impurities and achieve a purity of over 99%.

[0078] (9) Weigh the purified DCPD, non-ruthenium catalyst and hydroquinone respectively, in a mass ratio of 99:0.5:0.5.

[0079] (10) Mix the three components thoroughly in a beaker and perform vacuum defoaming treatment to prevent air bubbles from being sucked into the felt.

[0080] (11) Place the mixed resin solution after vacuum defoaming into the guide port. After the vacuum degree in the mold reaches 2Pa, open the guide port valve so that the resin solution is sucked into the mold to impregnate the felt material.

[0081] (12) After the resin has completely impregnated the felt, close the guide valve to stop the resin intake and keep the vacuum in the mold at 2 Pa.

[0082] (13) Place the mold back into the roller press and roll it repeatedly at 80°C 5 times until there are no obvious air bubbles in the felt material.

[0083] (14) Then transfer the mold to the curing oven and cure at 80°C for 20 minutes.

[0084] (15) After complete curing, open the sealing film, take out the composite material and trim it to obtain polydicyclopentadiene carbon fiber composite material.

[0085] result: Please see Figure 1 and Figure 2 The CF / UHMWPE / PDCPD composite material exhibits good mechanical properties, with a tensile strength of 180.1 MPa, a flexural strength of 357.6 MPa, and an impact strength of 126.2 MPa. Comparison with Example 1 reveals that while the composite material prepared using 1 cm carbon fiber in this example shows a decrease in tensile and flexural strength, its impact strength is slightly increased. This demonstrates that the use of high-toughness fiber (UHMWPE) can effectively control specific mechanical properties.

[0086] Comparative Example This invention proposes a polydicyclopentadiene carbon fiber composite material, which has significant differences compared with traditional polydicyclopentadiene carbon fiber composite materials.

[0087] Mainly includes: On the one hand, the polydicyclopentadiene carbon fiber composite material prepared by this invention has a stable and uniform internal fiber reinforcement structure, and does not deform during PDCPD impregnation. In contrast, traditional polydicyclopentadiene carbon fiber composites, due to the lack of pre-fixation during PDCPD impregnation, deform as the structure flows with the PDCPD, thus compromising the original reinforcement structure's performance. On the other hand, the polydicyclopentadiene carbon fiber composite material prepared by this invention undergoes multi-stage rolling after impregnation to ensure timely removal of air bubbles within the product. In contrast, traditional polydicyclopentadiene carbon fiber composites, after impregnation, suffer from relatively low molding pressure provided by the vacuum adsorption device, while the viscosity of PDCPD increases with the degree of polymerization, preventing the effective removal of internal air bubbles and leading to void defects within the polydicyclopentadiene carbon fiber composite material, thus reducing material performance.

[0088] Results Explanation: This invention presents a high-performance polydicyclopentadiene (PDCPD) / carbon fiber composite material and its innovative preparation method. By uniquely combining vacuum infusion molding with multi-stage gradient rolling assisted molding technology, the technical challenge of internal bubble defects in the material, inherent in traditional processes, is successfully overcome. The core innovation of this invention lies in: firstly, employing a vacuum infusion process to ensure sufficient resin wetting of the fibers; and then, using multi-stage gradient rolling technology to achieve progressive densification of the material, ultimately obtaining a composite material with excellent interfacial bonding and low porosity.

[0089] Rigorous testing and verification have shown that this preparation method significantly improves material quality, reducing the porosity of the composite material sheet from 7.85% in the traditional process to 0.3%, a reduction of 96.2%. This breakthrough not only effectively solves the bubble defect problem but also significantly improves the mechanical properties of the material. It provides reliable technical support for the application of polydicyclopentadiene composite materials in high-end fields such as aerospace and new energy vehicles.

[0090] It should be noted that the term "comprising," or any other variation thereof, is intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0091] The above are merely embodiments of this application and are not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. A method for preparing a polydicyclopentadiene carbon fiber composite material, characterized in that, include: S1. Cut carbon fiber and resin fiber, and wet-mix the cut short carbon fiber and short resin fiber to obtain carbon fiber felt. S2. Purify dicyclopentadiene to over 95%, add dicyclopentadiene polymerization catalyst, inhibitor, and stabilizer, mix evenly to obtain dicyclopentadiene resin mixture. S3. Place the mold containing the carbon fiber felt into a heated roller pressing device for pre-rolling to obtain carbon fiber felt with enhanced structural stability. S4. Cool the carbon fiber felt material with enhanced structural stability, transfer it into the mold for vacuum injection molding, draw a vacuum, and compact it under atmospheric pressure to obtain carbon fiber felt material with secondary enhanced stability. S5. The dicyclopentadiene resin mixture is drawn into the mold under air pressure to impregnate the carbon fiber felt material with secondary stability enhancement. The mold is then transferred back to the rolling equipment to perform secondary rolling on the carbon fiber felt material with secondary stability enhancement to obtain polydicyclopentadiene carbon fiber composite material.

2. The method for preparing polydicyclopentadiene carbon fiber composite material according to claim 1, characterized in that, The process involves cutting carbon fibers and resin fibers, then wet-blending the cut chopped carbon fibers and resin fibers to obtain carbon fiber felt, comprising: S11. Cut the continuous carbon fiber bundle into lengths of 1-10cm to obtain 1-1000g of short-cut carbon fiber. S12. Weigh a small amount of resin fiber and cut it to obtain 1~1000g of short resin fiber. S13. The cut short carbon fibers and the short resin fibers are wet-mixed to obtain carbon fiber felt.

3. The method for preparing polydicyclopentadiene carbon fiber composite material according to claim 1, characterized in that, The dicyclopentadiene is purified to over 95%, and a dicyclopentadiene polymerization catalyst, inhibitor, and stabilizer are added and mixed thoroughly to obtain a dicyclopentadiene resin mixture, comprising: S21. Dicyclopentadiene is purified by vacuum distillation to obtain dicyclopentadiene with a purity of over 95%. S22. Add 0.5~2wt% of dicyclopentadiene polymerization catalyst, 0.5~2wt% of inhibitor, and 0.5~2wt% of stabilizer to the dicyclopentadiene with a purity of 95% or higher, and mix evenly to obtain a dicyclopentadiene resin mixture.

4. The method for preparing polydicyclopentadiene carbon fiber composite material according to claim 1, characterized in that, The step of placing a mold containing the carbon fiber felt into a heated roller pressing device for pre-rolling to obtain a carbon fiber felt with enhanced structural stability includes: S31. The carbon fiber felt is laid flat on the mold, and the mold is placed flat in a roller pressing device with heating function for pre-rolling to make the carbon fiber felt flat. S32. By adjusting the temperature of the roller pressing equipment, the carbon fiber felt is hot-melted and bonded, resulting in a carbon fiber felt with enhanced structural stability and resistance to deformation.

5. The method for preparing polydicyclopentadiene carbon fiber composite material according to claim 1, characterized in that, The process of cooling the structurally enhanced carbon fiber felt, transferring it into a vacuum-cast mold, evacuating the vacuum, and compacting it under atmospheric pressure to obtain a carbon fiber felt with secondary enhanced stability includes: S41. Cool the carbon fiber felt material with enhanced structural stability, transfer it into the mold for vacuum injection molding, and lay the carbon fiber felt material with enhanced structural stability flat. S42. Seal the vacuum bag and place a fixed resin guide tube to ensure that the dicyclopentadiene resin mixture can uniformly and fully impregnate the carbon fiber felt material with enhanced structural stability. S43. Vacuuming is performed to create an internal vacuum within the carbon fiber structure, thereby obtaining a carbon fiber felt material with an internal vacuum. S44. The carbon fiber felt material with internal vacuum is compacted by atmospheric pressure to obtain a carbon fiber felt material with secondary enhanced stability.

6. The method for preparing the polydicyclopentadiene carbon fiber composite material according to claim 1, characterized in that, The dicyclopentadiene resin mixture is drawn into the mold under air pressure to impregnate the secondary stability-reinforced carbon fiber felt. The mold is then transferred back to the rolling mill for secondary rolling of the secondary stability-reinforced carbon fiber felt to obtain a polydicyclopentadiene carbon fiber composite material, comprising: S51. Open the mold switch and draw the dicyclopentadiene resin mixture into the mold under air pressure to impregnate the carbon fiber felt material with secondary stability enhancement. After full impregnation, close the mold switch. S52. Transfer the mold back to the rolling equipment and roll the carbon fiber felt material with secondary stability enhancement a second time. Use the rolling pressure to assist vacuum to remove air bubbles in the carbon fiber felt material with secondary stability enhancement, and ensure that the dicyclopentadiene resin mixture is fully impregnated. S53. When the dicyclopentadiene resin in the carbon fiber felt material to be reinforced with secondary stability is completely polymerized into polydicyclopentadiene, the mold is opened and the edge of the polydicyclopentadiene carbon fiber composite material is trimmed to obtain the polydicyclopentadiene carbon fiber composite material.

7. The method for preparing the polydicyclopentadiene carbon fiber composite material according to claim 1, characterized in that, The resin fiber is a thermoplastic resin fiber; the resin fiber includes one of PA66, PA6, PP, PE, PC, PPS, and PEEK; the resin fiber is cut to 1~3cm. The dicyclopentadiene polymerization catalyst is a ruthenium-based catalyst or a non-ruthenium catalyst; the ruthenium-based catalyst includes Grubbs catalyst; the non-ruthenium catalyst includes metal carbene catalyst and non-metal catalyst; The inhibitor is an inhibitor capable of inhibiting the ring-opening polymerization rate of dicyclopentadiene, and the inhibitor includes triphenyl phosphate, hydroquinone, and BHT; When the carbon fiber felt is rolled, the roller temperature is 10-20°C higher than the melting point of the resin fiber. The vacuum level is not less than 2 Pa.

8. The method for preparing polydicyclopentadiene carbon fiber composite material according to claim 2, characterized in that, The continuous carbon fiber is cut to a length of 4-8 cm.

9. A polydicyclopentadiene carbon fiber composite material, characterized in that, The polydicyclopentadiene carbon fiber composite material was prepared according to any one of claims 1 to 8.

10. The polydicyclopentadiene carbon fiber composite material according to claim 9, characterized in that, The porosity of the polydicyclopentadiene carbon fiber composite material is less than 0.3%.

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