Impact-resistant fiber-reinforced composite board as well as preparation process and application thereof

Abstract

The invention relates to the technical field of composite materials, in particular to an impact-resistant fiber-reinforced composite board as well as a preparation process and application thereof. The preparation process comprises the steps of interface coupling unit construction, multilayer hybrid fiber lamination, crosslinking enhancement treatment, thermal carbon synergistic treatment, vacuum micropore closing and the like. The interface bonding strength is improved through combination of atmosphere plasma activation and nano-silicon dioxide modified polyether-ether-ketone resin, the polyimide isolating membrane is introduced to achieve light weight and stability, and the mechanical property is optimized through aramid fiber / carbon fiber mixed fabric and thermal carbon cooperative treatment. The final composite board has excellent impact resistance, compactness and durability, and is suitable for protective equipment or load transfer structures. The high-performance performance of the composite board under the complex working condition can be remarkably improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of composite materials, and in particular relates to an impact-resistant fiber-reinforced composite plate and a preparation process and application thereof. Background Art

[0002] With the continuous development of industrial technology, the demand for composite materials with excellent mechanical properties is increasing, especially in fields that require high impact energy absorption performance and structural reliability, such as protective equipment, aerospace, automobile and other industries. Fiber-reinforced composite materials have been widely used due to their advantages such as high strength, light weight and impact resistance.

[0003] Traditional fiber-reinforced composites are mostly reinforced with carbon fiber or glass fiber, and the matrix usually uses thermosetting resins such as epoxy resins. However, existing composite materials show certain limitations when facing high-speed impact or other extreme working conditions, mainly reflected in their impact toughness and the density of the plate. In order to improve the impact resistance of fiber-reinforced composites, researchers have added new technologies and materials to the design of composites, such as optimizing the modification of resins, enhancing the bonding strength between layers, and improving the layered structure to improve the overall performance of the material.

[0004] In the existing technology, the method of using a reinforced fiber layer coated with a modified resin and high-temperature heat treatment and carbonization treatment to improve the strength and stability of composite materials has been widely used. However, these technologies still face technical bottlenecks such as how to further improve the impact energy absorption capacity of the material and how to optimize the density and durability of the material during the production process.

[0005] Therefore, how to prepare fiber-reinforced composite materials with higher impact energy absorption performance and stronger durability has become a technical problem that needs to be solved urgently. The present invention provides a method for preparing a new impact-resistant fiber-reinforced composite plate by optimizing the resin system of the coating area and the multi-stage heat treatment and carbonization process, aiming to solve the defects in the prior art and improve the comprehensive performance of the material. Summary of the invention

[0006] The present invention aims to provide an impact-resistant fiber-reinforced composite plate and a preparation process and application thereof. The preparation process is simple, the cost is low, and the plate is suitable for large-scale industrial production and application.

[0007] To achieve the above object, the technical solution adopted by the present invention is: S1a, construction of an interface coupling unit: performing atmospheric plasma activation treatment on a first reinforcing fiber fabric, and then spraying a modified polyetheretherketone resin containing nano-silicon dioxide on its surface to form a first interface coupling layer; wherein the mass of the first reinforcing fiber fabric is 1-2 times the mass of the polyimide isolation film; S1b, multi-layer mixed fiber stacking: stack the first interface coupling unit, the polyimide isolation film with a thickness of 20μm-30μm, and the second interface coupling unit in sequence, and cure them by vacuum hot extrusion at 60℃-80℃ and 1.0MPa-2.0MPa for 20min-40min to obtain an intermediate stacking module; wherein the mass of the second reinforcing fiber fabric is 1-2 times the mass of the polyimide isolation film; S2, cross-linking and strengthening treatment: after alternately stacking 3-5 layers of the middle stacking module and the aramid / carbon fiber mixed braid, place it in a mold, cross-link and cure for 30min-60min at 120℃-140℃ and 3.0MPa-4.5MPa to form a preliminary cured body; S3, hot carbon synergistic treatment: the preliminary solidified body is placed in a nitrogen protection furnace, first heated to 600°C at 4°C / min, kept warm for 1 hour, then heated to 1000°C at 2°C / min, kept warm for 1 hour; then chemical deposition is carried out at 900°C-1100°C and 0.5MPa, and then cooled to below 140°C to obtain a functionalized carbonized plate; S4. Vacuum micropore closure: Place the functionalized carbonized plate into a vacuum impregnation kettle, inject a polyamide-based penetrant with a concentration of 3wt%-5wt%, and impregnate it at 100℃-120℃ for 30min under the assistance of 0.05MPa vacuum, then perform a secondary pyrolysis treatment at 800℃-900℃, cool it to below 200℃ with the furnace, and finally obtain the target composite plate.

[0008] Specifically, the secondary pyrolysis treatment in step S4 is carried out under nitrogen protection, with the temperature raised to 800° C.-900° C. at 5° C. / min and kept at the constant temperature for 1 hour.

[0009] Preferably, the atmospheric plasma activation treatment time in step S1a is 10s-30s, and the power is 200W-300W, so as to ensure that the active groups on the fiber surface are fully exposed and improve the interface bonding strength.

[0010] Specifically, the first reinforcing fiber fabric and the second reinforcing fiber fabric are each independently a carbon fiber fabric or an aramid fiber fabric.

[0011] Preferably, the mass ratio of the aramid / carbon fiber blended fabric in step S2 is 1:1-2, and the blending angle is ±45°, so as to achieve a balanced distribution of mechanical properties.

[0012] Preferably, the weaving structure of the "aramid / carbon fiber blended fabric" is twill weave.

[0013] Specifically, the thickness of the polyimide isolation film is 20 μm-30 μm, and its mass accounts for 5%-15% of the total mass of the middle stack module to ensure the stability and lightweight characteristics of the interlayer structure.

[0014] Specifically, the first interface coupling layer is formed by mixing a modified polyetheretherketone resin with a SiO 2 The solutions of nanoparticles were mixed in a mass ratio of 1:0.5-1.5 and applied using a spraying process.

[0015] Specifically, the pressure range in the cross-linking and curing step is 3.0 MPa-4.5 MPa, the temperature range is 120° C.-140° C., and the duration is 30 min-60 min.

[0016] Specifically, during the vacuum impregnation process, the concentration of the polyamide-based penetrant is 3wt%-5wt%, and the impregnation is carried out for 30 minutes under a vacuum condition of 0.05MPa to effectively fill the micropores and improve the density of the composite board.

[0017] Specifically, the secondary pyrolysis treatment is carried out at a temperature of 800° C.-900° C. for 1 hour under vacuum conditions.

[0018] After spraying, a rapid cooling method with a cooling rate of not less than 50°C / min is immediately used to transform the polyetheretherketone resin from a fluid state to a solid state in a relatively short time, thereby promoting the nano-SiO 2 Directed deposition is formed at the interface and the migration of polymer segments is inhibited, thereby achieving the deposition and stabilization of a densified interface structure. This "rapid cooling deposition" process effectively improves the adhesion strength and thermal stability of the interface layer through the synergistic mechanism of rapid cooling-induced phase separation and rapid nucleation. Preferably, the rapid cooling method uses forced air cooling, that is, compressed air is quickly blown across the sample surface.

[0019] The present invention further provides an impact-resistant fiber-reinforced composite board prepared by the above-mentioned preparation process, wherein the impact strength thereof is ≥200 kJ / m², and the impact toughness thereof is significantly better than that of a conventional laminated fiber board.

[0020] The present invention further provides an application of an impact-resistant fiber-reinforced composite plate in protective equipment or a load transfer structure, wherein the composite plate is used to prepare a structural component with high impact energy absorption performance.

[0021] Preferably, the composite panel can be made into a honeycomb or grid structure to further enhance its anti-impact energy absorption performance.

[0022] Compared with the prior art, the present invention has the following beneficial effects: The present invention focuses on improving the interface coupling and multi-layer mixed weaving technology. Through the combination of atmospheric plasma activation treatment and nano-silicon dioxide modified polyetheretherketone resin, the bonding strength between the fiber and the matrix is ​​significantly improved, thereby enhancing the overall impact resistance of the composite board. At the same time, the introduction of the polyimide isolation membrane not only improves the stability of the interlayer structure, but also realizes a lightweight design. In addition, the alternating lamination of aramid / carbon fiber blended fabrics combined with synergistic hot carbon synergistic treatment enables the composite board to maintain excellent mechanical properties under high temperature and high pressure environments. Finally, the vacuum micropore closure process further improves the density and durability of the composite board through efficient filling of polyamide-based penetrants and secondary pyrolysis treatment, making it suitable for high-performance requirements under a variety of complex working conditions. DETAILED DESCRIPTION

[0023] The present invention is further described below in conjunction with specific embodiments, but the present invention is not limited to these embodiments. Those skilled in the art should recognize that the present invention covers all possible alternatives, improvements and equivalents within the scope of the claims.

[0024] Embodiment 1;

[0025] The impact-resistant fiberboard processing technology comprises the following steps: step S1a: interface coupling unit construction; step S1b: multi-layer mixed fiber stacking; step S2: cross-linking reinforcement treatment; step S3: hot carbon synergistic treatment; step S4: vacuum micropore closure.

[0026] In step S1a, the first reinforcing fiber fabric is selected as T700 carbon fiber plain weave fabric, whose surface density is 200g / m² and whose mass is 1.5 times that of the polyimide isolation film used. The carbon fiber fabric is subjected to atmospheric plasma treatment, and the treatment power is set to 250W and the treatment time is 20s.

[0027] Then, the modified resin system was prepared: polyetheretherketone (PEEK) resin was dissolved in NMP solvent, and 7wt% SiO 2 Nanoparticles, and PEEK:SiO 2 =1:1 mass ratio is mixed evenly, and dispersed for 30 minutes by ultrasonic frequency of 40kHz and power of 300W to form a modified mixed solution. The solution is evenly sprayed on the surface of the activated carbon fiber fabric using a spraying device, and pre-dried in hot air at 120°C for 10 minutes to form a first interface coupling layer.

[0028] In step S1b, a polyimide isolation film (PI film) with a thickness of 25 μm is selected, and its mass accounts for 10% of the total mass of the middle stacked module. The first interface coupling unit, the PI film, and the second interface coupling unit are stacked in sequence as a group. The second reinforcing fiber fabric is a Kevlar braid, which is 1.5 times the mass of the PI film, and is plasma activated and sprayed with modified PEEK / SiO 2 The resin is mixed to form a second interface coupling unit.

[0029] In step S2, the obtained intermediate stacking module is alternately stacked with aramid / carbon fiber hybrid fabric, with a total of 4 layers, the hybrid fabric adopts ±45° cross-weaving, and the ratio of aramid to carbon fiber is 1:1. The stacked structure is placed in a mold, cured at 130°C and 3.5MPa for 40 minutes, and cross-linked to obtain a preliminary cured body.

[0030] In step S3, the preliminary solidified body is placed in a nitrogen-protected tubular furnace, first heated to 600°C at a rate of 4°C / min and kept at that temperature for 1 hour, then heated to 1000°C at a rate of 2°C / min and kept at that temperature for another 1 hour. After the insulation is completed, it is immediately switched to a vacuum state (0.5MPa), and chemical deposition is performed at 900°C-1100°C and 0.5MPa, followed by forced air cooling at a rate of 50°C / min to 135°C to obtain a functionalized carbonized plate.

[0031] In step S4, the functionalized carbonized plate is placed in a vacuum impregnation kettle, a polyamide-based penetrant (pre-prepared with NMP as solvent) with a concentration of 4 wt% is injected, and the plate is immersed at 110°C for 30 minutes under the vacuum assistance of 0.05 MPa to allow the penetrant to evenly fill the microporous structure in the carbonized plate.

[0032] After impregnation, the board is subjected to secondary pyrolysis treatment at 800°C in a vacuum environment for 1 hour, and then naturally cooled to 200°C in the furnace to completely decompose the residual organic matter, close the microporous structure, and enhance the density and structural stability of the board.

[0033] Embodiment 2;

[0034] The impact-resistant fiberboard processing technology comprises the following steps: step S1a: interface coupling unit construction; step S1b: multi-layer mixed fiber stacking; step S2: cross-linking reinforcement treatment; step S3: hot carbon synergistic treatment; step S4: vacuum micropore closure.

[0035] In step S1a, the first reinforcing fiber fabric is selected as T700 carbon fiber plain weave fabric, whose surface density is 200g / m² and whose mass is 1 times that of the polyimide isolation film used. The carbon fiber fabric is subjected to atmospheric plasma treatment, with the treatment power set to 300W and the treatment time set to 10 seconds, so as to introduce active groups such as hydroxyl and carboxyl groups on its surface to enhance the interface affinity.

[0036] Then, the modified resin system was prepared: polyetheretherketone (PEEK) resin was dissolved in NMP solvent, 5wt% SiO 2 Nanoparticles, and PEEK:SiO 2 =1:0.5 mass ratio is mixed evenly, and dispersed for 30 minutes by ultrasonic frequency of 40kHz and power of 300W to form a modified mixed solution. The solution is evenly sprayed on the surface of the activated carbon fiber fabric using a spraying device, and pre-dried in hot air at 120°C for 10 minutes to form a first interface coupling layer.

[0037] In step S1b, a polyimide isolation film (PI film) with a thickness of 30 μm is selected, and its mass accounts for 5% of the total mass of the middle stacked module. The first interface coupling unit, the PI film, and the second interface coupling unit are stacked in sequence as a group. The second reinforcing fiber fabric is a woven aramid (Kevlar) fabric with a mass of 1 times that of the PI film, and the same process is used for plasma activation and spraying modified PEEK / SiO 2 The resin is mixed to form a second interface coupling unit.

[0038] In step S2, the obtained intermediate stacking module is alternately stacked with aramid / carbon fiber hybrid fabric, with a total of 3 layers, the hybrid fabric adopts ±45° cross-weaving, and the ratio of aramid to carbon fiber is 1:0.5. The stacked structure is placed in a mold, cured at 120°C and 4.5MPa for 30 minutes, and cross-linked to obtain a preliminary cured body.

[0039] In step S3, the preliminary solidified body is placed in a nitrogen-protected tube furnace, first heated to 600°C at a rate of 4°C / min and kept at that temperature for 1 hour, then heated to 1000°C at a rate of 2°C / min and kept at that temperature for another 1 hour. After the insulation is completed, it is immediately switched to a vacuum state (0.5MPa), and chemical deposition is performed at 900°C-1100°C and 0.5MPa, followed by forced air cooling at a rate of 50°C / min to 137°C to obtain a functionalized carbonized plate.

[0040] In step S4, the functionalized carbonized plate is placed in a vacuum impregnation kettle, a polyamide-based penetrant (pre-prepared with NMP as solvent) with a concentration of 5 wt% is injected, and the plate is immersed at 100°C for 30 minutes under the vacuum assistance of 0.05 MPa to allow the penetrant to evenly fill the microporous structure in the carbonized plate.

[0041] After impregnation, the board is subjected to secondary pyrolysis treatment at 850°C in a vacuum environment for 1 hour, and then naturally cooled to 200°C in the furnace to completely decompose the residual organic matter, close the microporous structure, and enhance the density and structural stability of the board.

[0042] Embodiment 3;

[0043] The impact-resistant fiberboard processing technology comprises the following steps: step S1a: interface coupling unit construction; step S1b: multi-layer mixed fiber stacking; step S2: cross-linking reinforcement treatment; step S3: hot carbon synergistic treatment; step S4: vacuum micropore closure.

[0044] In step S1a, the first reinforcing fiber fabric is selected as T700 carbon fiber plain weave fabric, whose surface density is 200g / m² and whose mass is twice that of the polyimide isolation film used. The carbon fiber fabric is subjected to atmospheric plasma treatment, with the treatment power set to 200W and the treatment time set to 30 seconds, so as to introduce active groups such as hydroxyl and carboxyl groups on its surface to enhance the interface affinity.

[0045] Then, the modified resin system was prepared: polyetheretherketone (PEEK) resin was dissolved in NMP solvent, 10wt% SiO 2 Nanoparticles, and PEEK:SiO 2 =1:0.5 mass ratio is mixed evenly, and dispersed for 30 minutes by ultrasonic frequency of 40kHz and power of 300W to form a modified mixed solution. The solution is evenly sprayed on the surface of the activated carbon fiber fabric using a spraying device, and pre-dried in hot air at 120°C for 10 minutes to form a first interface coupling layer.

[0046] In step S1b, a polyimide isolation film (PI film) with a thickness of 20 μm is selected, and its mass accounts for 15% of the total mass of the middle stacked module. The first interface coupling unit, the PI film, and the second interface coupling unit are stacked in sequence as a group. The second reinforcing fiber fabric is a woven aramid (Kevlar) fabric with a mass twice that of the PI film, and the same process is used for plasma activation and spraying modified PEEK / SiO 2 The resin is mixed to form a second interface coupling unit.

[0047] In step S2, the obtained intermediate stacking module is alternately stacked with aramid / carbon fiber hybrid fabric, with a total of 5 layers, the hybrid fabric adopts ±45° cross-weaving, and the ratio of aramid to carbon fiber is 1:2. The stacked structure is placed in a mold, cured at 140°C and 3.0MPa for 60 minutes, and cross-linked to obtain a preliminary cured body.

[0048] In step S3, the preliminary solidified body is placed in a nitrogen-protected tube furnace, first heated to 600°C at a rate of 4°C / min and kept at that temperature for 1 hour, then heated to 1000°C at a rate of 2°C / min and kept at that temperature for another 1 hour. After the insulation is completed, it is immediately switched to a vacuum state (0.5MPa), and chemical deposition is performed at 900°C-1100°C and 0.5MPa, followed by forced air cooling at a rate of 50°C / min, and cooled to 138°C to obtain a functionalized carbonized plate.

[0049] In step S4, the functionalized carbonized plate is placed in a vacuum impregnation kettle, a polyamide-based penetrant (pre-prepared with NMP as solvent) with a concentration of 3 wt% is injected, and the plate is immersed at 120°C for 30 min under the vacuum assistance of 0.05 MPa to allow the penetrant to evenly fill the microporous structure in the carbonized plate.

[0050] After impregnation, the board is subjected to secondary pyrolysis treatment at 900°C in a vacuum environment for 1 hour, and then naturally cooled to 200°C in the furnace to completely decompose the residual organic matter, close the microporous structure, and enhance the density and structural stability of the board.

[0051] Comparative Example 1 The reinforcing material was replaced with E-glass glass fiber cloth (alkali-free glass fiber) with a surface density of 200 g / m², and the other materials were the same as those in Example 1. The rest of the preparation process was the same as that in Example 1.

[0052] Comparative Example 2 The base resin is replaced with high-strength epoxy resin (E-51) + curing agent (TETA), without adding SiO 2 The laminated structure is the same, but the hot pressing conditions are adjusted to: heat curing at 120°C for 2 hours, then post-curing at 150°C for 2 hours, and cold pressing for demolding. The coordinated carbonization and vacuum closure steps are omitted, and the post-curing treatment is directly performed. The remaining materials are the same as those in Example 1. The remaining preparation process is the same as that in Example 1.

[0053] Comparative Example 3 Step S3 of hot carbon co-treatment is omitted, and the remaining materials are the same as those in Example 1. The remaining preparation process is the same as that in Example 1.

[0054] The test was carried out in accordance with GB / T1043.1-2008 (simply supported beam impact test) and GB / T9341-2008 (bending performance test).

[0055]

[0056] Table 1 Impact and bending test results In the drop hammer impact test (5J impact energy), the composite panel did not suffer through damage and had good impact energy dissipation and structural retention capabilities, making it suitable for high-strength protective structures.

[0057] In addition to the above embodiments, the present invention may also have other implementation modes. Any technical solution formed by equivalent replacement or equivalent transformation falls within the protection scope required by the present invention.

Claims

1. A method for preparing an impact-resistant fiber-reinforced composite plate, characterized in that: The following steps are involved: S1a, construction of an interface coupling unit: performing atmospheric plasma activation treatment on a first reinforcing fiber fabric, and then spraying a modified polyetheretherketone resin containing nano-silicon dioxide on its surface to form a first interface coupling layer; wherein the mass of the first reinforcing fiber fabric is 1-2 times the mass of the polyimide isolation film; S1b, multi-layer mixed fiber stacking: the polyimide isolation membrane of the first interface coupling unit and the second interface coupling unit are stacked in sequence, and cured by vacuum hot extrusion at 60°C-80°C and 1.0MPa-2.0MPa for 20min-40min to obtain an intermediate stacking module; wherein the mass of the second reinforcing fiber fabric is 1-2 times the mass of the polyimide isolation membrane; S2, cross-linking and strengthening treatment: after alternately stacking 3-5 layers of the middle stacking module and the aramid / carbon fiber mixed braid, place it in a mold, cross-link and cure for 30min-60min at 120℃-140℃ and 3.0MPa-4.5MPa to form a preliminary cured body; S3, hot carbon synergistic treatment: the preliminary solidified body is placed in a nitrogen protection furnace, first heated to 600°C at 4°C / min, kept warm for 1 hour, then heated to 1000°C at 2°C / min, kept warm for 1 hour; then chemical deposition is carried out at 900°C-1100°C and 0.5MPa, and then cooled to below 140°C to obtain a functionalized carbonized plate; S4. Vacuum micropore closure: Place the functionalized carbonized plate into a vacuum impregnation kettle, inject the polyamide-based penetrant, and impregnate it at 100℃-120℃ for 30 minutes under the assistance of 0.05MPa vacuum, then perform a secondary pyrolysis treatment at 800℃-900℃, cool it to below 200℃ with the furnace, and finally obtain the target composite plate.

2. The method for preparing an impact-resistant fiber-reinforced composite plate according to claim 1, characterized in that: The first reinforcing fiber fabric and the second reinforcing fiber fabric are each independently a carbon fiber fabric or an aramid fiber fabric.

3. The method for preparing an impact-resistant fiber-reinforced composite plate according to claim 1, characterized in that: The thickness of the polyimide isolation film is 20 μm-30 μm, and its mass accounts for 5%-15% of the total mass of the middle stack module.

4. The method for preparing an impact-resistant fiber-reinforced composite plate according to claim 1, characterized in that: The first interface coupling layer is formed by mixing the modified polyetheretherketone resin with a solution containing 5wt%-10wt% SiO2 nanoparticles at a mass ratio of 1:0.5-1.5 and using a spraying process.

5. The method for preparing an impact-resistant fiber-reinforced composite plate according to claim 1, characterized in that: The pressure range in the cross-linking and curing step is 3.0 MPa-4.5 MPa, the temperature range is 120° C.-140° C., and the duration is 30 min-60 min.

6. The method for preparing an impact-resistant fiber-reinforced composite plate according to claim 1, characterized in that: The cooling method is forced air cooling.

7. The method for preparing an impact-resistant fiber-reinforced composite plate according to claim 1, characterized in that: During the vacuum impregnation process, the concentration of the polyamide-based penetrant is 3wt%-5wt%, and the impregnation is carried out for 30 minutes under a vacuum condition of 0.05MPa.

8. The method for preparing an impact-resistant fiber-reinforced composite plate according to claim 1, characterized in that: The atmospheric plasma activation treatment time in step S1a is 10s-30s, and the power is 200W-300W.

9. An impact-resistant fiber-reinforced composite plate prepared by the method according to any one of claims 1 to 8, characterized in that: Its impact strength is ≥200kJ / m².

10. Use of the impact-resistant fiber-reinforced composite plate according to claim 9 in protective equipment or load transfer structures, characterized in that: The composite plate is used for preparing structural components with high impact energy absorption performance.

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