A fiber reinforced polymer composite based on in-situ polymerization at interface and a preparation method and application thereof

Abstract

The application belongs to the cross field of high-performance composite material manufacturing process and interface engineering, and specifically comprises a fiber-reinforced polymer composite based on interface in-situ polymerization and a preparation method and application thereof. The preparation method comprises the following steps: soaking an activated fiber fabric in a silane coupling agent solution to obtain a silane coupling agent modified fiber fabric, and taking out; uniformly coating an initiator solution on the surface of the silane coupling agent modified fiber fabric, and drying; coating a polymer prepolymer liquid on the surface of the dried fiber fabric to coat the fiber and fill the fabric gap, and initiating in-situ polymerization reaction. The application realizes in-situ growth and strong bonding of a polymer matrix on the interface of inorganic fibers by constructing a coupling agent grafted layer on the surface of the inorganic fibers and further directly prepositioning an initiator on the surface, thereby completely solving the problems of weak interface bonding force, low polymerization efficiency at the interface and difficulty in balancing strength and toughness in the traditional process.

Description

Technical Field

[0001] This invention belongs to the interdisciplinary field of high-performance composite material manufacturing technology and interface engineering, specifically including a fiber-reinforced polymer composite material based on in-situ interfacial polymerization, its preparation method and application. Background Technology

[0002] With the increasing demand for lightweight and high-strength materials in modern industry, fiber-reinforced polymer composites have been widely used in aerospace, rail transportation, robotics, automobiles, medical devices, lightweight sports equipment, and building structural protection due to their high specific strength, high specific modulus, corrosion resistance, and good moldability. In composite material systems, the interface region between the fiber and the polymer matrix is ​​considered a key hub for stress transfer, and the bonding state of the interface directly determines the macroscopic mechanical properties of the material, such as tensile strength, impact toughness, and fatigue life.

[0003] Currently, the most common technique for improving the interfacial compatibility between fibers and organic polymer matrices (such as acrylate, epoxy, and polyester resins) is to modify the fiber surface using silane coupling agents. More specifically, the process involves immersing the fiber in a solution containing the silane coupling agent, which then undergoes a condensation reaction with the hydroxyl groups on the fiber surface, grafting polymerizable carbon-carbon double bonds onto the fiber surface using silane molecules. An initiator is then directly dissolved in the liquid polymer monomer or oligomer matrix. Finally, the silane-grafted fiber is placed in a system containing the initiator, and the entire matrix is ​​cured by heating or light, achieving copolymerization between the active chains in the matrix and the coupling agent double bonds on the fiber surface.

[0004] However, the aforementioned traditional methods have the following significant drawbacks in practical applications: 1. Low interfacial polymerization efficiency: In traditional processes, the initiator is uniformly distributed in the bulk matrix. Due to the steric hindrance effect on the fiber surface and the resistance to diffusion of macromonomers to the fiber surface, the double bonds on the silane on the fiber surface cannot fully participate in the polymerization reaction. The effective collision probability at the interface is low, and the reaction is incomplete. This incomplete chemical bonding makes the interfacial layer a weak point for stress transmission, and fiber delamination is very likely to occur under stress. 2. Influence of oxygen inhibition effect: For free radical polymerization systems, trace amounts of oxygen often remain in the micropores and interfacial gaps on the fiber surface. This significantly inhibits the polymerization reaction at the interface, leading to a further decrease in interfacial bonding force and seriously affecting the dynamic mechanical properties of the composite material. 3. Difficulty in achieving both strength and toughness: Due to the low interfacial reaction efficiency, the interface formed by traditional methods is difficult to achieve high-density surface grafting, resulting in weak adhesion. When subjected to high strain rate impact, the interface cannot effectively buffer and dissipate energy, often leading to brittle fracture of the material, failing to meet the dual requirements of high strength and high toughness.

[0005] Therefore, how to develop a novel interface modification method that can significantly enhance interfacial bonding strength, improve interfacial polymerization efficiency, and endow composite materials with excellent mechanical properties is a key problem that urgently needs to be solved in the field of high-performance composite materials. Summary of the Invention

[0006] In view of the problems existing in the prior art, the first objective of this invention is to provide a method for preparing fiber-reinforced polymer composite materials based on in-situ interfacial polymerization. By directly pre-placing an initiator on the surface of inorganic fibers modified with a silane coupling agent, in-situ growth and strong bonding of the polymer matrix at the inorganic fiber interface are achieved, completely solving the problems of incomplete interfacial polymerization, weak interfacial bonding, and difficulty in balancing strength and toughness in traditional processes.

[0007] A second objective of this invention is to provide a fiber-reinforced polymer composite material prepared using the preparation method described above.

[0008] The third objective of this invention is to provide an application of the fiber-reinforced polymer composite material described above in the preparation of automotive body parts, core components of robots, aerospace interior panels, sports equipment, and wind turbine blades.

[0009] To achieve the first objective mentioned above, the technical solution adopted by the present invention includes:

[0010] This invention discloses a method for preparing fiber-reinforced polymer composite materials based on interfacial in-situ polymerization, comprising the following steps:

[0011] S1. Immerse the activated fiber fabric in a silane coupling agent solution to obtain a silane coupling agent modified fiber fabric, and then remove it.

[0012] S2. The initiator solution is uniformly coated on the surface of the silane coupling agent-modified fiber fabric and then dried.

[0013] S3. Coat the surface of the dry fiber fabric with a polymer prepolymer liquid to cover the fibers and fill the gaps in the fabric, thereby initiating an in-situ polymerization reaction to obtain the final product.

[0014] To address the problems of weak interfacial bonding, low polymerization efficiency at the interface, and difficulty in balancing strength and toughness in existing fiber-reinforced polymer composites, this invention provides a method for preparing high-strength and high-toughness fiber-reinforced polymer composites based on interface modification. This invention constructs a "surface initiation source" by directly pre-applying an initiator to the fiber surface modified with a silane coupling agent, allowing the polymerization reaction to grow retrogradely from the fiber surface to the resin matrix. This ensures extremely high-density covalent bonding at the interface. Furthermore, this method effectively counteracts the inhibitory effect of residual oxygen at the micro-interface on free radical polymerization (oxygen inhibition effect), ensuring seamless chemical bonding between the fiber and the matrix at the microscale. Due to the high-density covalent grafting, the material can dissipate impact energy through molecular chain deformation while transferring stress, thereby significantly improving both strength and toughness.

[0015] Furthermore, the fiber skeleton material of the fiber fabric is selected from one of carbon fiber, glass fiber, basalt fiber, aramid fiber, and ultra-high molecular weight polyethylene fiber.

[0016] Furthermore, the silane coupling agent is selected from one or more of 3-(methacryloyloxy)propyltrimethoxysilane (KH570), 2-methacrylate-3-(methyldichlorosilyl)propane (alcohol), and 3-acryloyloxypropyltrimethoxysilane (KBM-5103).

[0017] Furthermore, the mass concentration of the silane coupling agent solution is 0.5-10.0%; for example, the mass concentration of the silane coupling agent solution can be 0.5%, 1.0%, 2.0%, 3.0%, 4.0%, 5.0%, 6.0%, 7.0%, 8.0%, 9.0%, 10.0%, etc.

[0018] Furthermore, the initiator is selected from one or more of the following ultraviolet initiators: DEAP (2,2-diethoxyacetophenone), Irgacure 1173, TPO ((2,4,6-trimethylbenzoyl)diphenylphosphine oxide), TPO-L (ethyl 2,4,6-trimethylbenzoylphenylphosphonate), MBF (methyl benzoylformate), etc., and thermal initiators such as tert-butyl peroxide and tert-butyl peroxyneodecanate (TBPND).

[0019] Furthermore, the mass concentration of the initiator solution is 0.2-5 wt%, preferably 0.5-3 wt%. For example, the mass concentration of the initiator solution can be 0.5 wt%, 1 wt%, 1.5 wt%, 2 wt%, 2.5 wt%, 3 wt%, etc.

[0020] Furthermore, the amount of the initiator solution coated on the surface of the fiber fabric is 2-20 ml / m. 2For example, the amount of initiator coated on the surface of the fiber fabric can be 5 ml / m. 2 10 ml / m 2 15 ml / m 2 20 ml / m 2 wait.

[0021] It should also be noted that this invention pre-places the initiator directly on the fiber surface, resulting in a higher concentration of initiator at the fiber interface compared to the traditional process where the initiator is dispersed in the polymer matrix. However, this high concentration of initiator does not pose the risk of explosive polymerization or uneven curing caused by excessively high concentrations in traditional processes. This is because, firstly, explosive polymerization is essentially thermal runaway caused by heat accumulation. In this invention, the high concentration of initiator is pre-placed on an extremely thin, micron-sized fiber surface. The reaction is mainly concentrated in the extremely thin solid-liquid interface layer, and the reaction area is negligible. The polymerization heat generated at the interface is rapidly conducted to the surrounding matrix resin and the fiber itself, making it impossible to form macroscopic heat accumulation. Therefore, thermodynamically, the conditions for explosive polymerization are not met. Secondly, explosive polymerization requires a sufficient amount of monomers to participate in the reaction instantaneously. However, in the system of this invention, the fiber surface has a high density of double bonds of silane coupling agents. The free radicals generated by the initiator are consumed by a large number of double bonds on the surface, and the diffusion rate of monomers to the interface limits the reaction, thus failing to meet the conditions for explosive polymerization. Therefore, high concentrations of initiators not only do not lead to explosive polymerization, but also generate densely distributed covalent anchor bonds, perfectly achieving the goal of enhancing interfacial adhesion strength.

[0022] Furthermore, the purpose of pre-activating the fiber fabric is to expose more hydroxyl groups to facilitate subsequent grafting with the silane coupling agent. Technicians can choose commonly used activation methods in the field, such as plasma treatment, chemical etching, ultraviolet / ozone treatment, and corona treatment, as the activation effects obtained from these methods are similar. In one specific embodiment, the activation treatment of the fiber fabric includes: immersing the fiber fabric in acetone solvent for a certain period of time, washing it, and then activating the washed fiber fabric with a strong oxidizing detergent or plasma.

[0023] Furthermore, the strong oxidizing cleaning solution includes, but is not limited to, one or more of the following: piranha cleaning solution (a mixture of sulfuric acid and hydrogen peroxide), concentrated sulfuric acid, and hydrogen peroxide.

[0024] Furthermore, the activation treatment is carried out at a temperature of 50-90 ℃ for 1-5 h.

[0025] Furthermore, the polymer prepolymer liquid is prepared according to the following steps:

[0026] The product is obtained by mixing monomers containing active groups, natural polymers with thermally reversible gel properties, toughening modifiers, and solvents in a certain proportion and heating to dissolve them.

[0027] The raw materials forming the polymer prepolymer liquid consist of monomers, natural polymers, toughening modifiers and solvents, with monomers accounting for 60-90 wt%, natural polymers accounting for 1-10 wt%, toughening modifiers accounting for 1-10 wt%, and the remainder being solvents.

[0028] Furthermore, the heating temperature during the preparation of the polymer prepolymer solution is 50-100℃.

[0029] Furthermore, the monomer is selected from one or more of acrylamide, hydroxyethylacrylamide, and N,N-dimethylacrylamide.

[0030] Furthermore, the natural polymer is selected from one or more of gelatin, agarose, carrageenan, gellan gum, and sodium alginate;

[0031] Furthermore, the toughening modifier selected in this invention is a polyol toughening modifier, such as one or more of ethylene glycol, propylene glycol, glycerin, and polyethylene glycol.

[0032] Furthermore, the solvent is water.

[0033] Furthermore, the amount of the polymer prepolymer liquid coated on the surface of the fiber fabric is 0.3-2 L / m. 2 For example, the amount of the polymer prepolymer liquid coated on the surface of the fiber fabric can be 0.3 L / m. 2 0.5L / m 2 0.8L / m 2 1L / m 2 1.3L / m 2 1.5L / m 2 1.8L / m 2 2L / m 2 wait.

[0034] Furthermore, the methods for initiating in-situ polymerization reactions include thermal initiation or ultraviolet light initiation;

[0035] The intensity of ultraviolet light irradiation is 10-200 mW / cm². 2 The in-situ polymerization reaction takes 10-240 min;

[0036] The thermal initiation conditions are a temperature of 60-150℃ and an in-situ polymerization reaction time of 60-1000 min.

[0037] For example, the present invention uses ultraviolet light irradiation to initiate polymerization, and the initiator used is also an ultraviolet light initiator. Of course, those skilled in the art can also replace the polymerization method with thermal initiation or electron beam initiation, which are common initiation methods of the present invention. It is only necessary to match the corresponding initiator type and initiation conditions. They will not be listed one by one here.

[0038] Furthermore, prior to the in-situ polymerization reaction initiation step, the preparation method further includes stacking fiber fabrics coated with polymer prepolymer liquid and pressing them together to obtain a laminate.

[0039] Among them, the stacked fiber fabrics are 1-30 layers;

[0040] The pressing pressure is 0.2-5.0 MPa, and the holding time is 10-40 min.

[0041] To achieve the second objective mentioned above, the technical solution adopted by the present invention includes:

[0042] This invention discloses a fiber-reinforced polymer composite material prepared by the preparation method described above.

[0043] To achieve the third objective mentioned above, the technical solution adopted by the present invention includes:

[0044] This invention discloses the application of the fiber-reinforced polymer composite material described above in the preparation of automotive body parts (e.g., hoods / engine covers, roof covers, battery pack shells (underbody panels) for new energy vehicles), interior trim (steering wheels, door panel trims), carbon fiber rear wings), robot components (e.g., industrial robot arms, robot joints), aerospace interior panels, sports equipment (e.g., skis, golf clubs), and wind turbine blades.

[0045] Beneficial effects of this invention:

[0046] This invention constructs a "surface initiation source" by directly pre-placing an initiator on the surface of a fiber modified with a silane coupling agent, enabling the polymerization reaction to grow in reverse from the fiber surface to the bulk matrix. This ensures extremely high density of covalent bonds at the interface, enhances the degree of polymerization at the interface, and achieves high-density covalent grafting, thereby significantly improving the impact toughness of the material while increasing its strength.

[0047] This invention enables precise control of the interfacial strength, tensile strength, and other mechanical properties of fiber-reinforced polymer composites by changing the type of silane coupling agent, the amount of initiator coating, the ratio of monomers to natural polymers in the prepolymer solution, and the amount of prepolymer solution coating.

[0048] The preparation process provided by this invention is simple, the curing speed is fast, the experimental conditions are easy to control, and no complex high-temperature and high-pressure equipment is required. It is easy to scale up production and has broad prospects for industrial application.

[0049] The fiber-reinforced polymer composite material prepared by this invention has excellent tensile properties and structural stability, and can be used in a wide range of fields such as aerospace, key robot components, automobile manufacturing, building reinforcement, and sports equipment. Attached Figure Description

[0050] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0051] Figure 1 A scanning electron microscope image of the fracture surface of the material prepared in Example 1 is shown.

[0052] Figure 2 A scanning electron microscope image of the fracture surface of the material prepared in Comparative Example 1 is shown.

[0053] Figure 3 The tensile curves of the materials prepared in Example 1 and Comparative Example 1 are shown for comparison.

[0054] Figure 4 The bending strength curves of the materials prepared in Example 1 and Comparative Example 1 are shown for comparison.

[0055] Figure 5 The tensile curves of the materials prepared in Example 2 and Comparative Example 2 are shown for comparison.

[0056] Figure 6 The tensile curves of the materials prepared in Example 3 and Comparative Example 3 are shown for comparison.

[0057] Figure 7 The tensile curves of the materials prepared in Example 1 and Comparative Examples 4 and 5 are shown for comparison.

[0058] Figure 8 The tensile curves of the materials prepared in Example 1 and Example 4 are shown for comparison.

[0059] Figure 9 The tensile curves of the materials prepared in Example 1 and Example 5 are shown for comparison. Detailed Implementation

[0060] To more clearly illustrate the present invention, the following description, in conjunction with preferred embodiments and accompanying drawings, further clarifies the invention. It should be understood that the described embodiments are merely some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0061] Example 1

[0062] A method for preparing a high-strength, high-toughness carbon fiber reinforced polymer composite material includes the following steps:

[0063] a) Arrange the cut 20 cm × 20 cm carbon fibers in a 150 ml Soxhlet extractor and reflux extract with acetone as solvent for 24 h to remove the original sizing agent or organic modifier on its surface. After washing and drying, a clean carbon fiber cloth is obtained.

[0064] b) Place the clean carbon fiber cloth into a plasma cleaner and activate it for 5 minutes at a power of 200 W in an air atmosphere.

[0065] c) Soak the activated carbon fiber cloth in a 0.5 wt% solution of silane coupling agent KH570 (ethanol as solvent) for 24 hours to fully modify it;

[0066] d) The UV initiator Irgacure 1173 was added to ethanol and ultrasonically stirred for 10 min to obtain an initiator solution with a mass fraction of 0.5 wt%. The initiator solution was then uniformly coated onto the surface of the carbon fiber cloth treated in step b), with a coating amount of 15 ml / m². 2 After coating, dry at 60 ℃ for later use;

[0067] e) Add 100 g acrylamide monomer, 5.8 g agarose, 8.3 g glycerol, and 15.6 g water to a flask and mechanically stir at 65 °C for 40 min to fully dissolve and mix them to obtain a polymer prepolymer solution.

[0068] f) Place the carbon fiber cloth treated in step d) in a mold, and drip-coat the polymer prepolymer liquid to allow the polymer prepolymer liquid to penetrate the upper and lower surfaces of the carbon fiber cloth. Then, continue to overlap and lay the second layer of carbon fiber cloth, and drip-coat the polymer prepolymer liquid again. Lay a total of 10 layers. Then, use a laminator to laminate and compact the material under a pressure of 3.0 MPa, and vacuum degas for 10 min to remove bubbles, to obtain the laminated part. The amount of polymer prepolymer liquid dripped onto the surface of each layer of carbon fiber cloth is 10 ml.

[0069] g) The laminate obtained in step f) was placed under a UV light source and in-situ polymerized and cured for 30 min at a wavelength of 365 nm and a light intensity of 50 mW / cm². The laminate was then demolded to obtain the finished product. Characterization was performed using SEM (see [link to SEM description]). Figure 1The synthesized high-strength, high-toughness carbon fiber reinforced polymer composite material exhibits a dense interfacial bond with no significant porosity. The polymer matrix uniformly encapsulates the fiber skeleton. Tensile fracture occurred at the fiber fracture surface, rather than fiber pull-out, indicating extremely strong fiber-polymer adhesion. The dense interface and uniform encapsulation eliminate potential interfacial defects (such as microcracks and voids), ensuring efficient and complete stress transfer from the relatively tough polymer matrix to the high-strength, high-modulus carbon fiber skeleton. When the material reaches its stress limit, the interfacial strength is sufficient to withstand the load until the fiber itself reaches its fracture strength and fails, rather than slipping out due to interfacial debonding. This signifies that the fiber reinforcement effect has been maximized.

[0070] This ideal fracture mode not only ensures that the composite material can withstand loads (high strength) far exceeding those of the pure matrix material, but also that the fiber fracture process requires more energy to consume, thereby effectively absorbing impact and significantly improving mechanical properties.

[0071] Comparative Example 1

[0072] a) Arrange the cut 20 cm × 20 cm carbon fibers in a 150 ml Soxhlet extractor and reflux extract with acetone as solvent for 24 h to remove the original sizing agent or organic modifier on its surface. After washing and drying, a clean carbon fiber cloth is obtained.

[0073] b) Place the clean carbon fiber cloth into a plasma cleaner and activate it for 5 minutes at a power of 200 W in an air atmosphere.

[0074] c) Soak the activated carbon fiber cloth in a 0.5 wt% solution of silane coupling agent KH570 (solvent is ethanol) for 24 hours;

[0075] d) Add 100 g acrylamide monomer, 5 g agarose, 8 g glycerol, and 15 g water to a flask and mechanically stir at 65 °C for 40 min to fully dissolve and mix them to obtain a polymer prepolymer solution.

[0076] e) Add 0.13g of UV photoinitiator Irgacure 1173 to the prepolymer solution and continue stirring for 2 min;

[0077] f) Place the carbon fiber cloth treated in step c) in a mold, and drip-coat the polymer prepolymer liquid to allow the polymer prepolymer liquid to penetrate the upper and lower surfaces of the carbon fiber cloth. Then, continue to overlap and lay the second layer of carbon fiber cloth, and drip-coat the polymer prepolymer liquid again. Lay a total of 10 layers. Then, use a laminator to laminate and compact the material under a pressure of 3.0 MPa, and vacuum degas for 10 min to remove bubbles, to obtain the laminated part. The amount of polymer prepolymer liquid dripped onto the surface of each layer of carbon fiber cloth is 10 ml.

[0078] g) The laminate obtained in step f) was placed under a UV light source and in-situ polymerized and cured for 30 min at a wavelength of 365 nm and a light intensity of 50 mW / cm². The laminate was then demolded to obtain the finished product. Characterization was performed using SEM (see [link to SEM description]). Figure 2 The carbon fiber reinforced polymer prepared using the aforementioned traditional methods exhibited extensive fiber pull-out at the fracture surface, with smooth interface fracture. This extensive fiber pull-out and smooth interface fracture indicate insufficient interfacial bonding strength between the fiber and the matrix. This means that no effective physical or chemical bond has formed between the fiber and the polymer matrix, or the bond strength is far lower than the strength of the fiber itself. When the material is under stress, the stress cannot be effectively transferred from the matrix to the fiber, or the stress borne by the fiber cannot be fully transferred to the surrounding matrix, causing the fiber to "slip out" of the matrix before fracture. Because the fiber fails to effectively bear the load, the overall tensile strength of the composite material decreases significantly, resulting in a shortened service life, reduced protective function, and even potential harm to the user's personal safety.

[0079] Mechanical property tests showed that the tensile stress of the material prepared in Comparative Example 1 was 453.6 MPa, while the tensile stress of the material prepared in Example 1 was 635.4 MPa. This indicates that the material prepared in Example 1 exhibited a significant improvement in tensile strength, with an increase exceeding 30% (see [link to relevant documentation]). Figure 3 ).

[0080] The shear force test of single fiber droplets also revealed that the material prepared in Example 1 showed a significant improvement in the adhesion force at the single fiber interface. The shear force at the single fiber interface of the material prepared in Comparative Example 1 was 83.1 ± 3.9 N, while that of the material prepared in Example 1 was 52.9 ± 5.4 N.

[0081] Flexural strength: The flexural strength of the material prepared in Comparative Example 1 is 1077.8 MPa, and the fracture energy is 6.42 MJ / m. 3 The material prepared in Example 1 has a flexural strength of 1731.6 MPa and a fracture energy of 10.85 MJ / m. 3 (See) Figure 4 ).

[0082] Example 2

[0083] A method for preparing a high-strength, high-toughness glass fiber reinforced polymer composite material includes the following steps:

[0084] a) Arrange the cut 20 cm × 20 cm glass fibers in a 150 ml Soxhlet extractor and reflux extract with acetone as solvent for 24 h to remove the original sizing agent or organic modifiers on the surface. After washing and drying, a clean glass fiber cloth is obtained.

[0085] b) Place the clean fiberglass cloth into a plasma cleaner and activate it for 10 minutes at 100 W under an argon atmosphere.

[0086] c) Soak the activated carbon fiber cloth in a 2 wt% silane coupling agent KH570 solution (ethanol as solvent) for 24 hours to fully modify it;

[0087] d) The UV photoinitiator TPO was added to ethanol and ultrasonically dispersed for 10 min to obtain an initiator solution with a mass fraction of 0.5 wt%. The initiator solution was then uniformly coated onto the surface of the glass fiber cloth treated in step b), with a coating amount of 10 ml / m². 2 After coating, dry at 60 ℃ for later use;

[0088] e) Add 150 g of hydroxyethyl acrylamide, 10.9 g of agar, 13.2 g of ethylene glycol, and 25.6 g of water to the reactor and mechanically stir at 85 °C for 60 min to fully dissolve and mix them to obtain a polymer prepolymer solution.

[0089] f) Place the glass fiber cloth treated in step d) in a mold, and drip-coat the polymer prepolymer liquid to allow the polymer prepolymer liquid to penetrate the upper and lower surfaces of the glass fiber cloth. Then, continue to overlap and lay the second layer of glass fiber cloth, and drip-coat the polymer prepolymer liquid again. Lay a total of 20 layers. Then, use a laminator to laminate and compact the glass fiber cloth under a pressure of 2.0 MPa, and vacuum degas for 15 min to remove bubbles, to obtain the laminated part. The amount of polymer prepolymer liquid dripped onto the surface of each layer of glass fiber cloth is 20 ml.

[0090] g) Place the laminate obtained in step f) under an ultraviolet light source and polymerize and cure in situ for 30 min under the conditions of wavelength of 365 nm and light intensity of 100 mW / cm², and then demold to obtain the finished product.

[0091] Comparative Example 2

[0092] a) Arrange the cut 20 cm × 20 cm glass fibers in a 150 ml Soxhlet extractor and reflux extract with acetone as solvent for 24 h to remove the original sizing agent or organic modifiers on the surface. After washing and drying, a clean glass fiber cloth is obtained.

[0093] b) Place the clean fiberglass cloth into a plasma cleaner and activate it for 10 minutes at 100 W under an argon atmosphere.

[0094] c) Soak the activated glass fiber cloth in a 0.5 wt% solution of silane coupling agent KH570 (solvent is ethanol) for 24 h;

[0095] d) Add 150 g of hydroxyethyl acrylamide monomer, 10.9 g of agar, 13.2 g of ethylene glycol, and 25.6 g of water to a flask and mechanically stir at 85 °C for 60 min to fully dissolve and mix them to obtain a polymer prepolymer solution;

[0096] e) Add 0.2g of UV photoinitiator TPO to the prepolymer solution and continue stirring for 2 min;

[0097] f) Place the glass fiber cloth treated in step c) in a mold, and drip-coat the polymer prepolymer liquid to allow the polymer prepolymer liquid to penetrate the upper and lower surfaces of the carbon fiber cloth. Then, continue to overlap and lay the second layer of glass fiber cloth, and drip-coat the polymer prepolymer liquid again. Lay a total of 20 layers. Then, use a laminator to laminate and compact the material under a pressure of 2.0 MPa, and vacuum degas for 15 min to remove bubbles, to obtain the laminated part. The amount of polymer prepolymer liquid dripped onto the surface of each layer of glass fiber cloth is 20 ml.

[0098] g) Place the laminate obtained in step f) under an ultraviolet light source and polymerize and cure in situ for 30 min under the conditions of wavelength of 365 nm and light intensity of 100 mW / cm², and then demold to obtain the finished product.

[0099] Mechanical property testing showed that the tensile strength of the material prepared in Example 2 was significantly improved compared to that prepared in Comparative Example 2, with a tensile stress of 373 MPa (see [reference]). Figure 5 ).

[0100] Example 3

[0101] A method for preparing a high-strength, high-toughness basalt fiber reinforced polymer composite material includes the following steps:

[0102] a) Arrange the cut 20 cm × 20 cm basalt fibers in a 150 ml Soxhlet extractor and reflux extract with acetone as solvent for 24 h to remove the original sizing agent or organic modifier on its surface. After washing and drying, a clean basalt fiber cloth is obtained.

[0103] b) Place the clean basalt fiber cloth into a plasma cleaner and activate it for 3 minutes at 100 W in an oxygen atmosphere.

[0104] c) Soak the activated carbon fiber cloth in a 2 wt% solution of silane coupling agent KBM-5103 (ethanol as solvent) for 24 hours to fully modify it;

[0105] d) The UV initiator TPO-L was added to ethanol and ultrasonically dispersed for 10 min to obtain an initiator solution with a mass fraction of 0.5 wt%. The initiator solution was then uniformly coated onto the surface of the basalt fiber cloth treated in step b), with a coating amount of 12 ml / m². 2 After coating, dry at 60 ℃ for later use;

[0106] e) Add 80 g of acrylamide monomer, 2.5 g of sodium alginate, 5.8 g of polyethylene glycol, and 8.3 g of water to a reaction vessel and mechanically stir at 50 °C for 30 min to fully dissolve and mix them to obtain a polymer prepolymer solution.

[0107] f) Place the basalt fiber cloth treated in step d) in a mold, and drip-coat the polymer prepolymer liquid to allow the polymer prepolymer liquid to penetrate the upper and lower surfaces of the basalt fiber cloth. Then, continue to overlap and lay the second layer of basalt fiber cloth, and drip-coat the polymer prepolymer liquid again. Lay a total of 5 layers. Then, use a laminator to laminate and compact the material under a pressure of 0.5 MPa, and vacuum degas for 5 minutes to remove bubbles, to obtain the laminated part. The amount of polymer prepolymer liquid dripped onto the surface of each layer of basalt fiber cloth is 20 ml.

[0108] g) Place the laminate obtained in step f) under an ultraviolet light source and polymerize and cure in situ for 30 min under the conditions of wavelength 365 nm and light intensity 30 mW / cm², and then demold to obtain the finished product.

[0109] Comparative Example 3

[0110] a) Arrange the cut 20 cm × 20 cm basalt fibers in a 150 ml Soxhlet extractor and reflux extract with acetone as solvent for 24 h to remove the original sizing agent or organic modifier on its surface. After washing and drying, a clean basalt fiber cloth is obtained.

[0111] b) Place the clean basalt fiber cloth into a plasma cleaner and activate it for 3 minutes at 100 W in an oxygen atmosphere.

[0112] c) Soak the activated basalt fiber cloth in a 0.5 wt% silane coupling agent KH570 solution (ethanol as solvent) for 24 hours;

[0113] d) Add 80 g of acrylamide monomer, 2.5 g of sodium alginate, 5.8 g of polyethylene glycol, and 8.3 g of water to a flask and mechanically stir at 50 °C for 30 min to fully dissolve and mix them to obtain a polymer prepolymer solution.

[0114] e) Add 0.1g of UV photoinitiator TPO-L to the polymer prepolymer solution and continue stirring for 2 min;

[0115] f) Place the basalt fiber cloth treated in step c) in a mold, and drip-coat the polymer prepolymer liquid to allow the polymer prepolymer liquid to penetrate the upper and lower surfaces of the basalt fiber cloth. Then, continue to overlap and lay the second layer of basalt fiber cloth, and drip-coat the polymer prepolymer liquid again. Lay a total of 5 layers. Then, use a laminator to laminate and compact the material under a pressure of 0.5 MPa, and vacuum degas for 5 minutes to remove bubbles, to obtain the laminated part. The amount of polymer prepolymer liquid dripped onto the surface of each layer of basalt fiber cloth is 20 ml.

[0116] g) Place the laminate obtained in step f) under an ultraviolet light source and polymerize and cure in situ for 30 min under the conditions of wavelength 365 nm and light intensity 30 mW / cm², and then demold to obtain the finished product.

[0117] Mechanical property testing showed that the tensile strength of the material prepared in Example 3 was significantly improved compared to that of the material prepared in Comparative Example 3, with a tensile stress of 582.2 MPa (see [link to example]). Figure 6 ).

[0118] Comparative Example 4

[0119] a) Arrange the cut 20 cm × 20 cm carbon fibers in a 150 ml Soxhlet extractor and reflux extract with acetone as solvent for 24 h to remove the original sizing agent or organic modifier on its surface. After washing and drying, a clean carbon fiber cloth is obtained.

[0120] b) Place the clean carbon fiber cloth into a plasma cleaner and activate it for 5 minutes at a power of 200 W in an air atmosphere.

[0121] c) Soak the activated carbon fiber cloth in a 0.5 wt% solution of silane coupling agent KH570 (ethanol as solvent) for 24 hours to fully modify it;

[0122] d) The UV initiator Irgacure 1173 was added to ethanol and ultrasonically stirred for 10 min to obtain an initiator solution with a mass fraction of 10 wt%. The initiator solution was then uniformly coated onto the surface of the carbon fiber cloth treated in step b), with a coating amount of 30 ml / m². 2 After coating, dry at 60 ℃ for later use;

[0123] e) Add 100 g acrylamide monomer, 5.8 g agarose, 8.3 g glycerol, and 15.6 g water to a flask and mechanically stir at 65 °C for 40 min to fully dissolve and mix them to obtain a polymer prepolymer solution.

[0124] f) Place the carbon fiber cloth treated in step d) in a mold, and drip-coat the polymer prepolymer liquid to allow the polymer prepolymer liquid to penetrate the upper and lower surfaces of the carbon fiber cloth. Then, continue to overlap and lay the second layer of carbon fiber cloth, and drip-coat the polymer prepolymer liquid again. Lay a total of 10 layers. Then, use a laminator to laminate and compact the material under a pressure of 3.0 MPa, and vacuum degas for 10 min to remove bubbles, to obtain the laminated part. The amount of polymer prepolymer liquid dripped onto the surface of each layer of carbon fiber cloth is 10 ml.

[0125] g) The laminate obtained in step f) was placed under a UV light source and in-situ polymerized and cured for 30 min at a wavelength of 365 nm and a light intensity of 50 mW / cm². The product was then demolded to obtain the final product. Tensile properties were tested. Due to the excessively high initiator concentration, explosive polymerization occurred at the interface, resulting in performance significantly lower than the sample prepared in Example 1 (see [link to example]). Figure 7 ).

[0126] Comparative Example 5

[0127] a) Arrange the cut 20 cm × 20 cm carbon fibers in a 150 ml Soxhlet extractor and reflux extract with acetone as solvent for 24 h to remove the original sizing agent or organic modifier on its surface. After washing and drying, a clean carbon fiber cloth is obtained.

[0128] b) Place the clean carbon fiber cloth into a plasma cleaner and activate it for 5 minutes at a power of 200 W in an air atmosphere.

[0129] c) Soak the activated carbon fiber cloth in a 0.5 wt% solution of silane coupling agent KH570 (ethanol as solvent) for 24 hours to fully modify it;

[0130] d) The UV initiator Irgacure 1173 was added to ethanol and ultrasonically dispersed for 10 min to obtain an initiator solution with a mass fraction of 0.05 wt%. The initiator solution was then uniformly coated onto the surface of the carbon fiber cloth treated in step b), with a coating amount of 5 ml / m². 2 After coating, dry at 60 ℃ for later use;

[0131] e) Add 100 g acrylamide monomer, 5.8 g agarose, 8.3 g glycerol, and 15.6 g water to a flask and mechanically stir at 65 °C for 40 min to fully dissolve and mix them to obtain a polymer prepolymer solution.

[0132] f) Place the carbon fiber cloth treated in step d) in a mold, and drip-coat the polymer prepolymer liquid to allow the polymer prepolymer liquid to penetrate the upper and lower surfaces of the carbon fiber cloth. Then, continue to overlap and lay the second layer of carbon fiber cloth, and drip-coat the polymer prepolymer liquid again. Lay a total of 10 layers. Then, use a laminator to laminate and compact the material under a pressure of 3.0 MPa, and vacuum degas for 10 min to remove bubbles, to obtain the laminated part. The amount of polymer prepolymer liquid dripped onto the surface of each layer of carbon fiber cloth is 10 ml.

[0133] g) Place the laminate obtained in step f) under a UV light source and polymerize and cure in situ for 30 min at a wavelength of 365 nm and a light intensity of 50 mW / cm². Demold to obtain the finished product. Perform tensile property testing on the material. Due to the low initiator concentration, the overall polymerization effect of the material is poor, and the performance is far lower than that of the sample prepared in Example 1 (see...). Figure 7 ).

[0134] Example 4

[0135] A method for preparing a high-strength, high-toughness carbon fiber reinforced polymer composite material includes the following steps:

[0136] a) Arrange the cut 20 cm × 20 cm carbon fibers in a 150 ml Soxhlet extractor and reflux extract with acetone as solvent for 24 h to remove the original sizing agent or organic modifier on its surface. After washing and drying, a clean carbon fiber cloth is obtained.

[0137] b) Place the clean carbon fiber cloth into a plasma cleaner and activate it for 5 minutes at a power of 200 W in an air atmosphere.

[0138] c) Soak the activated carbon fiber cloth in a 0.5 wt% solution of silane coupling agent KH570 (ethanol as solvent) for 24 hours to fully modify it;

[0139] d) The UV initiator Irgacure 1173 was added to ethanol and ultrasonically stirred for 10 min to obtain an initiator solution with a mass fraction of 1.0 wt%. The initiator solution was then uniformly coated onto the surface of the carbon fiber cloth treated in step b), with a coating amount of 20 ml / m². 2 After coating, dry at 60 ℃ for later use;

[0140] e) Add 100 g acrylamide monomer, 5.8 g agarose, 8.3 g glycerol, and 15.6 g water to a flask and mechanically stir at 65 °C for 40 min to fully dissolve and mix them to obtain a polymer prepolymer solution.

[0141] f) Place the carbon fiber cloth treated in step d) in a mold, and drip-coat the polymer prepolymer liquid to allow the polymer prepolymer liquid to penetrate the upper and lower surfaces of the carbon fiber cloth. Then, continue to overlap and lay the second layer of carbon fiber cloth, and drip-coat the polymer prepolymer liquid again. Lay a total of 10 layers. Then, use a laminator to laminate and compact the material under a pressure of 3.0 MPa, and vacuum degas for 10 min to remove bubbles, to obtain the laminated part. The amount of polymer prepolymer liquid dripped onto the surface of each layer of carbon fiber cloth is 20 ml.

[0142] g) The laminate obtained in step f) was placed under an ultraviolet light source and in-situ polymerized and cured for 30 min at a wavelength of 365 nm and a light intensity of 50 mW / cm². The laminate was then demolded to obtain the finished product. Tensile strength testing was performed, and the performance was comparable to that of Example 1 (see...). Figure 8 ).

[0143] Example 5

[0144] A method for preparing a high-strength, high-toughness carbon fiber reinforced polymer composite material includes the following steps:

[0145] a) Arrange the cut 20 cm × 20 cm carbon fibers in a 150 ml Soxhlet extractor and reflux extract with acetone as solvent for 24 h to remove the original sizing agent or organic modifier on its surface. After washing and drying, a clean carbon fiber cloth is obtained.

[0146] b) Place the clean carbon fiber cloth into a plasma cleaner and activate it for 5 minutes at a power of 200 W in an air atmosphere.

[0147] c) Soak the activated carbon fiber cloth in a 0.5 wt% solution of silane coupling agent KH570 (solvent is ethanol) for 24 hours;

[0148] d) Add the thermal initiator tert-butyl peroxide to ethanol and ultrasonically disperse for 10 min to obtain an initiator solution with a mass fraction of 0.5 wt%. Then, uniformly coat the initiator solution onto the surface of the carbon fiber cloth treated in step c), with a coating amount of 15 ml / m² on the carbon fiber cloth surface. 2 After coating, dry at 60 ℃ for later use;

[0149] e) Add 100 g acrylamide monomer, 5.8 g agarose, 8.3 g glycerol, and 15.6 g water to a flask and mechanically stir at 65 °C for 40 min to fully dissolve and mix them to obtain a polymer prepolymer solution.

[0150] f) Place the carbon fiber cloth treated in step d) in a mold, and drip-coat the polymer prepolymer liquid to allow the polymer prepolymer liquid to penetrate the upper and lower surfaces of the carbon fiber cloth. Then, continue to overlap and lay the second layer of carbon fiber cloth, and drip-coat the polymer prepolymer liquid again. Lay a total of 10 layers. Then, use a laminator to laminate and compact the material under a pressure of 3.0 MPa, and vacuum degas for 10 min to remove bubbles, to obtain the laminated part. The amount of polymer prepolymer liquid dripped onto the surface of each layer of carbon fiber cloth is 10 ml.

[0151] g) Place the laminate obtained in step f) in an oven and cure it in situ at 90°C for 300 min. Demold to obtain the finished product. Perform tensile strength testing; the performance is comparable to that of Example 1 (see Example 1). Figure 9 ).

[0152] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is impossible to exhaustively list all possible implementations here. All embodiments falling under the scope of the present invention...

[0153] Obvious variations or modifications derived from the technical solution are still within the scope of protection of this invention.

Claims

1. A method for preparing fiber-reinforced polymer composite materials based on interfacial in-situ polymerization, characterized in that, Includes the following steps: S1. Immerse the activated fiber fabric in a silane coupling agent solution to obtain a silane coupling agent modified fiber fabric, and then remove it. S2. The initiator solution is uniformly coated on the surface of the silane coupling agent-modified fiber fabric and then dried. S3. Coat the surface of the dry fiber fabric with a polymer prepolymer liquid to cover the fibers and fill the gaps in the fabric, thereby initiating an in-situ polymerization reaction to obtain the product. The silane coupling agent is selected from one or more of 3-(methacryloyloxy)propyltrimethoxysilane, 2-methacrylate-3-(methyldichlorosilyl)propane (alcohol), and 3-acryloyloxypropyltrimethoxysilane; In the raw materials forming the polymer prepolymer liquid, monomers account for 60-90 wt%, natural polymers account for 1-10 wt%, toughening regulators account for 1-10 wt%, and the remainder is solvent; The initiator solution has a mass concentration of 0.2-5 wt%. The amount of the initiator solution applied to the surface of the fiber fabric is 2-20 ml / m. 2 .

2. The preparation method according to claim 1, characterized in that, The concentration of the silane coupling agent solution is 0.5-10.0 wt%.

3. The preparation method according to claim 1, characterized in that, The initiator is selected from one or more of DEAP, Irgacure 1173, TPO, TPO-L, MBF, tert-butyl peroxide, and tert-butyl peroxyneodecanate.

4. The preparation method according to claim 1, characterized in that, The polymer prepolymer liquid was prepared according to the following steps: The product is obtained by mixing monomers containing active groups, natural polymers with thermally reversible gel properties, toughening regulators, and solvents in a certain proportion and heating to dissolve them.

5. The preparation method according to claim 4, characterized in that, The monomer is selected from one or more of acrylamide, hydroxyethylacrylamide, and N,N-dimethylacrylamide; The natural polymer is selected from one or more of gelatin, agarose, carrageenan, chitosan, and sodium alginate; The toughening modifier is selected from one or more of ethylene glycol, propylene glycol, glycerin, and polyethylene glycol; The solvent is water.

6. The preparation method according to claim 1, characterized in that, The amount of the polymer prepolymer liquid coated on the surface of the fiber fabric is 0.3-2.0 L / m. 2 .

7. The preparation method according to claim 1, characterized in that, Initiation of in-situ polymerization reactions can be achieved through thermal initiation or ultraviolet light initiation; The ultraviolet light initiation conditions are as follows: the intensity of ultraviolet light irradiation is 10-200 mW / cm². 2 The in-situ polymerization reaction takes 10-240 min; The thermal initiation conditions are a temperature of 60-150℃ and an in-situ polymerization reaction time of 60-1000 min.

8. The preparation method according to claim 1, characterized in that, Before the initiation of the in-situ polymerization reaction step, the preparation method further includes stacking fiber fabrics with applied polymer prepolymer liquid and pressing them together to obtain a laminate. Among them, the stacked fiber fabrics are 1-30 layers; The pressing pressure is 0.2-5.0 MPa, and the holding time is 10-40 min.

9. A fiber-reinforced polymer composite material, characterized in that, It is prepared by the preparation method according to any one of claims 1-8.

10. The application of the fiber-reinforced polymer composite material as described in claim 9 in the preparation of automotive body parts, robot components, aerospace interior panels, sports equipment, and wind turbine blades.

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