Fiber reinforced resin composite material based on coordination dynamic network and preparation method thereof

Abstract

The invention discloses a preparation method of a fiber reinforced resin composite material based on a coordination dynamic network. The preparation method comprises the following steps: S1, preparing a composite dispersion; step S2, preparing a modified resin prepolymer; s3, mixing the modified resin prepolymer and a fatty amine curing agent according to the molar ratio of epoxy groups to amino groups of 1: (0.95-1), stirring and dispersing after mixing, and extracting bubbles generated in the stirring process by using vacuum equipment to obtain resin to be cured; secondly, completely infiltrating the cut fiber cloth into resin to be cured for at least 20 minutes, then sequentially laying the fiber cloth in a mold layer by layer, and pressing the fiber cloth to extrude bubbles in the fiber cloth in the laying process to obtain a sample to be cured; and S4, putting the to-be-cured sample obtained in the step S3 into a drying oven, carrying out hot-pressing curing for 4-8 hours under the conditions of 1MPa and 70-90 DEG C, taking out the to-be-cured sample, and demolding to obtain the fiber-reinforced resin composite material based on the coordination dynamic network.

Description

Technical Field

[0001] This invention belongs to the field of composite materials, specifically relating to a fiber-reinforced resin composite material based on a coordination dynamic network and its preparation method. Background Technology

[0002] Fiber-reinforced resin composites (such as carbon fiber reinforced polymers, or CFRP) are widely used in key structural components of drones and new energy vehicles due to their high specific strength and specific stiffness. However, CFRP has the following shortcomings in use: 1. Traditional thermosetting resins (such as epoxy resins) achieve high strength and stiffness through high-density covalent cross-linking, but the cross-linking network restricts molecular chain movement, resulting in significant brittleness and insufficient fracture toughness in carbon fiber composites; 2. The surface of reinforcing fibers (such as carbon fibers) is chemically inert and smooth, and the bonding with the resin matrix mainly relies on physical-mechanical interlocking and weak van der Waals forces, resulting in limited interfacial bonding strength. These two factors lead to low fracture toughness and impact damage resistance in carbon fiber composites. Under external impact, carbon fiber composites are prone to fracture, resulting in a significant decrease in load-bearing capacity.

[0003] To address the aforementioned shortcomings of carbon fiber composites, two main methods are currently employed for toughening design. The first method involves toughening the resin matrix (e.g., adding rubber particles or thermoplastic resins). While this method can improve toughness, it often comes at the cost of significantly reduced stiffness and strength. Furthermore, because it cannot effectively improve the fiber-resin interfacial strength, its toughening effect on carbon fiber composites is often unsatisfactory. The second method involves modifying the carbon fiber surface (e.g., fiber surface oxidation, coating, grafting) to improve the fiber-resin interfacial strength. However, the material properties of carbon fiber composites are simultaneously influenced by both interfacial properties and resin matrix properties. Controlling or improving only one aspect often has limited effect, failing to achieve a synergistic improvement in the stiffness, strength, and toughness of carbon fiber composites. Summary of the Invention

[0004] Purpose of the invention: The present invention addresses the problems existing in the prior art by disclosing a fiber-reinforced resin composite material based on a coordination dynamic network and its preparation method.

[0005] Technical solution: A method for preparing fiber-reinforced resin composites based on coordination dynamic networks, comprising the following steps in parts by mass: Step S1, Preparation of the composite dispersion: S11. Add 1 part of boron source to 8 to 12 parts of dispersant, and stir at 90°C to 110°C until the boron source is completely lost to obtain a fluid. S12. Slowly add 35 to 40 parts of nanofiller to the fluid obtained in step S11, and continuously shear and stir for at least 1 hour. After completion, a uniform and stable composite dispersion is obtained. Step S2, Preparation of modified resin prepolymer: Add 90-110 parts of thermosetting resin to the composite dispersion obtained in step S12, and stir and pre-react at 40°C-120°C for at least 1 hour to obtain a modified resin prepolymer. Step S3, Molding: S31. The modified resin prepolymer obtained in step S2 is mixed with the fatty amine curing agent at a molar ratio of epoxy group to amine group of 1:0.95-1. After mixing, the mixture is stirred and dispersed, and the air bubbles generated during the stirring process are removed using a vacuum device to obtain the resin to be cured. S32. The cut fiber cloth is completely immersed in the resin to be cured obtained in step S31 for at least 20 minutes, and then it is laid in layers in the mold. During the layering process, the fiber cloth is pressed to squeeze out the air bubbles to obtain the sample to be cured. Step S4, Curing: The sample to be cured obtained in step S3 is placed in an oven and hot-pressed and cured at 1 MPa and 70℃~90℃ for 4~8 hours. After removal and demolding, the fiber-reinforced resin composite material based on coordination dynamic network is obtained.

[0006] The fiber-reinforced resin composite material based on coordination dynamic network is prepared by any one of the methods described above.

[0007] The main innovations and inventive mechanisms of this invention are as follows: 1. Dispersion and stabilization mechanism: The dispersant prevents the agglomeration of boron source particles through physical coating and steric hindrance effect, and utilizes its rheological properties to make it uniformly suspended in the resin. 2. Dynamic network construction mechanism: During the curing process, boron forms coordinate bonds (such as BO, BN) with heteroatoms on the resin chain (such as -OH generated by epoxy ring opening, -NH- in the curing agent). The bond energy of these coordinate bonds is lower than that of covalent bonds and is reversible, thereby introducing a dynamic softening point in the rigid covalent crosslinking network. 3. Dynamic interfacial bonding mechanism: Some boron elements migrate to the resin-reinforcement interface and form similar dynamic coordination bonds with the polar functional groups on the surface of the reinforcement. This dynamic interfacial bonding is stronger than physical action, and because of its reversibility, it can dissipate energy through bond breaking and recombination when subjected to force, thus preventing the rapid expansion of interfacial debonding.

[0008] Beneficial effects: The fiber-reinforced resin composite material based on coordination dynamic network and its preparation method disclosed in this invention have the following beneficial effects: 1. Synergistic performance improvement: For the first time, the "toughening" of the resin matrix and the "strengthening" of its interface with the fiber are achieved simultaneously in fiber-reinforced resin composites. This breaks the contradiction between toughening and strengthening in traditional technologies, enabling fiber composites to achieve extremely high fracture toughness, impact resistance and damage tolerance while maintaining high stiffness and high strength.

[0009] 2. The preparation process is highly versatile: the process is simple and easy to combine with existing composite material molding processes (such as hand lay-up and prepreg hot pressing); 3. Significant performance improvement: Post-impact compressive strength is improved by at least 39.67%, interfacial shear strength is improved by at least 160.57%, and simply supported beam impact strength is improved by at least 36.32%. Attached Figure Description

[0010] Figure 1 This is a flowchart of the preparation method of fiber-reinforced resin composite material based on coordination dynamic network disclosed in this invention. Detailed Implementation

[0011] The specific embodiments of the present invention are described in detail below.

[0012] The "range" disclosed in this invention is defined by a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, which define the boundaries of a particular range. Ranges defined in this way can include or exclude endpoints and can be arbitrarily combined; that is, any lower limit can be combined with any upper limit to form a range. For example, if a range of 10–50 is listed for a specific parameter, it is also expected that ranges of 10–40 and 20–50 are also included. Furthermore, if the minimum range values ​​are 1 and 2, and the maximum range values ​​are 3, 4, and 5, then the following ranges are all expected: 1–3, 1–4, 1–5, 2–3, 2–4, and 2–5. In this application, unless otherwise stated, the numerical range "a–b" represents a shortened representation of any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "0–5" means that all real numbers between "0–5" have been listed herein; "0–5" is merely a shortened representation of these numerical combinations.

[0013] Unless otherwise specified, all embodiments and optional embodiments of this application can be combined to form new technical solutions.

[0014] Unless otherwise specified, all technical features and optional technical features of this application may be combined to form new technical solutions.

[0015] Unless otherwise specified, all steps in this application may be performed sequentially or randomly, preferably sequentially. For example, the method includes steps (a) and (b), indicating that the method may include steps (a) and (b) performed sequentially, or it may include steps (b) and (a) performed sequentially. For example, the mention that the method may also include step (c) indicates that step (c) may be added to the method in any order. For example, the method may include steps (a), (b), and (c), or it may include steps (a), (c), and (b), or it may include steps (c), (a), and (b), etc.

[0016] Unless otherwise specified, the terms "comprising" and "including" as used in this application can be open-ended or closed-ended. For example, "comprising" and "including" can mean that other components not listed may also be included, or that only the listed components may be included.

[0017] Unless otherwise specified, the reaction will proceed under normal temperature and pressure conditions.

[0018] Unless otherwise specified, all parts or percentages are by weight or by weight percentage.

[0019] In this invention, all the substances used are known substances that can be purchased or synthesized by known methods.

[0020] In this invention, all the devices or equipment used are conventional devices or equipment known in the art and are readily available.

[0021] The preparation method of fiber-reinforced resin composites based on coordination dynamic networks, by weight, includes the following steps: Step S1, Preparation of the composite dispersion: S11. Add 1 part of boron source to 8 to 12 parts of dispersant, and stir at 90°C to 110°C until the boron source is completely lost to obtain a fluid. S12. Slowly add 35 to 40 parts of nanofiller to the fluid obtained in step S11, and continuously shear and stir for at least 1 hour. After completion, a uniform and stable composite dispersion is obtained. Step S2, Preparation of modified resin prepolymer: Add 90-110 parts of thermosetting resin to the composite dispersion obtained in step S12, and stir and pre-react at 40°C-120°C for at least 1 hour to obtain a modified resin prepolymer. Step S3, Molding: S31. The modified resin prepolymer obtained in step S2 is mixed with the fatty amine curing agent at a molar ratio of epoxy group to amine group of 1:0.95-1. After mixing, the mixture is stirred and dispersed, and the air bubbles generated during the stirring process are removed using a vacuum device to obtain the resin to be cured. S32. The cut fiber cloth is completely immersed in the resin to be cured obtained in step S31 for at least 20 minutes, and then it is laid in layers in the mold. During the layering process, the fiber cloth is pressed to squeeze out the air bubbles to obtain the sample to be cured. Step S4, Curing: The sample to be cured obtained in step S3 is placed in an oven and hot-pressed and cured at 1 MPa and 70℃~90℃ for 4~8 hours. After removal and demolding, the fiber-reinforced resin composite material based on coordination dynamic network is obtained.

[0022] Furthermore, the boron source mentioned in step S11 is one of boric acid, phenylboronic acid, borate esters, and organoboranes.

[0023] Furthermore, the organoborane has the general structural formula BR3, where R is a C1-C3 alkyl group.

[0024] Furthermore, the stirring speed in step S11 is 400-600 rpm.

[0025] Further, the dispersant mentioned in step S11 is one of polyethylene glycol, hydroxyl silicone oil, and polyvinyl alcohol; Preferably, the dispersant in step S11 is polyvinyl alcohol.

[0026] Furthermore, the molecular weight of the polyethylene glycol is 360 to 440.

[0027] Furthermore, the molecular weight of the polyvinyl alcohol is 25,000 to 35,000.

[0028] Furthermore, the nanofiller mentioned in step S12 is one or more of nano-silica, nano-silicon carbide, and nano-calcium carbonate; Preferably, the nanofiller in step S12 is fumed nano-silica.

[0029] Furthermore, the stirring speed of the shearing and stirring in step S12 is 400-600 rpm.

[0030] Further, the thermosetting resin mentioned in step S2 is one of epoxy resin, phenolic resin and unsaturated polyester resin; Preferably, the thermosetting resin in step S2 is an epoxy resin.

[0031] Furthermore, the stirring speed in step S2 is 400-600 rpm.

[0032] Furthermore, the fatty amine curing agent mentioned in step S31 is one of triethylenetetramine and ethylenediamine.

[0033] Furthermore, the stirring speed in step S31 is 300-500 rpm.

[0034] Furthermore, the fiber cloth mentioned in step 32 is carbon fiber cloth or polyimide fiber cloth.

[0035] The fiber-reinforced resin composite material based on coordination dynamic network is prepared by any one of the methods described above.

[0036] In one embodiment: The preparation method of fiber-reinforced resin composites based on coordination dynamic networks, by weight, includes the following steps: Step S1, Preparation of the composite dispersion: S11. Add 1 part of boron source to 8 parts of dispersant, stir at 90°C until the boron source is completely lost to obtain a fluid; S12. Slowly add 35 parts of nanofiller to the fluid obtained in step S11, and continue shearing and stirring for 1 hour. After completion, a uniform and stable composite dispersion is obtained. Step S2, Preparation of modified resin prepolymer: Add 90 parts of thermosetting resin to the composite dispersion obtained in step S12, stir and pre-react at 40°C for 24 hours, and obtain the modified resin prepolymer after completion. Step S3, Molding: S31. The modified resin prepolymer obtained in step S2 is mixed with the fatty amine curing agent at a molar ratio of epoxy group to amine group of 1:0.95. After mixing, the mixture is stirred and dispersed, and the air bubbles generated during the stirring process are removed using a vacuum device to obtain the resin to be cured. S32. The cut fiber cloth is completely immersed in the resin to be cured obtained in step S31 for 20 minutes, and then it is laid in layers in the mold. During the layering process, the fiber cloth is pressed to squeeze out the air bubbles to obtain the sample to be cured. Step S4, Curing: The sample to be cured obtained in step S3 is placed in an oven and hot-pressed and cured at 1 MPa and 70°C for 8 hours. After removal and demolding, the fiber-reinforced resin composite material based on coordination dynamic network is obtained.

[0037] Furthermore, the boron source mentioned in step S11 is an organoborane.

[0038] Furthermore, the organoborane has the general structural formula BR3, wherein R is methyl. In another embodiment, the organoborane has the general structural formula BR3, wherein R is n-propyl. In yet another embodiment, the organoborane has the general structural formula BR3, wherein R is ethyl.

[0039] Furthermore, the stirring speed in step S11 is 400 rpm.

[0040] Furthermore, the dispersant mentioned in step S11 is polyethylene glycol.

[0041] Furthermore, the polyethylene glycol has a molecular weight of 360. In another embodiment, the polyethylene glycol has a molecular weight of 440. In yet another embodiment, the polyethylene glycol has a molecular weight of 400.

[0042] Further, the nanofiller mentioned in step S12 is nano-silica. In another embodiment, the nanofiller mentioned in step S12 is fumed nano-silica.

[0043] Furthermore, the stirring speed of the shearing and stirring in step S12 is 400 rpm.

[0044] Furthermore, the thermosetting resin mentioned in step S2 is an epoxy resin.

[0045] Furthermore, the stirring speed in step S2 is 400 rpm.

[0046] Furthermore, the fatty amine curing agent mentioned in step S31 is triethylenetetramine.

[0047] Furthermore, the stirring speed in step S31 is 300 rpm.

[0048] Furthermore, the fiber cloth mentioned in step 32 is carbon fiber cloth.

[0049] The fiber-reinforced resin composite material based on coordination dynamic network is prepared by any one of the methods described above.

[0050] In another embodiment: The preparation method of fiber-reinforced resin composites based on coordination dynamic networks, by weight, includes the following steps: Step S1, Preparation of the composite dispersion: S11. Add 1 part of boron source to 12 parts of dispersant, stir at 110°C until the boron source is completely lost to obtain a fluid; S12. Slowly add 40 parts of nanofiller to the fluid obtained in step S11, and continuously shear and stir for 6 hours. After completion, a uniform and stable composite dispersion is obtained. Step S2, Preparation of modified resin prepolymer: 110 parts of thermosetting resin were added to the composite dispersion obtained in step S12, and the mixture was stirred at 120°C for 1 hour to pre-react, and a modified resin prepolymer was obtained after the reaction was completed. Step S3, Molding: S31. The modified resin prepolymer obtained in step S2 is mixed with the fatty amine curing agent at a molar ratio of epoxy group to amine group of 1:1. After mixing, the mixture is stirred and dispersed, and the air bubbles generated during the stirring process are extracted using a vacuum device to obtain the resin to be cured. S32. The cut fiber cloth is completely immersed in the resin to be cured obtained in step S31 for 60 minutes, and then it is laid in layers in the mold. During the layering process, the fiber cloth is pressed to squeeze out the air bubbles to obtain the sample to be cured. Step S4, Curing: The sample to be cured obtained in step S3 is placed in an oven and hot-pressed and cured at 1 MPa and 90°C for 4 hours. After removal and demolding, the fiber-reinforced resin composite material based on coordination dynamic network is obtained.

[0051] Furthermore, the boron source mentioned in step S11 is boric acid.

[0052] Furthermore, the stirring speed in step S11 is 600 rpm.

[0053] Furthermore, the dispersant mentioned in step S11 is hydroxyl silicone oil.

[0054] Furthermore, the nanofiller mentioned in step S12 is nano-silicon carbide.

[0055] Furthermore, the stirring speed of the shearing and stirring in step S12 is 600 rpm.

[0056] Furthermore, the thermosetting resin mentioned in step S2 is a phenolic resin.

[0057] Furthermore, the stirring speed in step S2 is 600 rpm.

[0058] Furthermore, the fatty amine curing agent mentioned in step S31 is ethylenediamine.

[0059] Furthermore, the stirring speed in step S31 is 500 rpm.

[0060] Furthermore, the fiber cloth mentioned in step 32 is a polyimide fiber cloth.

[0061] The fiber-reinforced resin composite material based on coordination dynamic network is prepared by any one of the methods described above.

[0062] In yet another embodiment: The preparation method of fiber-reinforced resin composites based on coordination dynamic networks, by weight, includes the following steps: Step S1, Preparation of the composite dispersion: S11. Add 1 part of boron source to 10 parts of dispersant, stir at 100°C until the boron source is completely lost to obtain a fluid; S12. Slowly add 38 parts of nanofiller to the fluid obtained in step S11, and continuously shear and stir for 2 hours. After completion, a uniform and stable composite dispersion is obtained. Step S2, Preparation of modified resin prepolymer: 100 parts of thermosetting resin were added to the composite dispersion obtained in step S12, and the mixture was stirred at 90°C for 2 hours to pre-react, and a modified resin prepolymer was obtained after the reaction was completed. Step S3, Molding: S31. The modified resin prepolymer obtained in step S2 is mixed with the fatty amine curing agent at a molar ratio of epoxy group to amine group of 1:0.98. After mixing, the mixture is stirred and dispersed, and the air bubbles generated during the stirring process are removed using a vacuum device to obtain the resin to be cured. S32. The cut fiber cloth is completely immersed in the resin to be cured obtained in step S31 for 40 minutes, and then it is laid in layers in the mold. During the layering process, the fiber cloth is pressed to squeeze out the air bubbles to obtain the sample to be cured. Step S4, Curing: The sample to be cured obtained in step S3 is placed in an oven and hot-pressed and cured at 1 MPa and 80°C for 6 hours. After removal and demolding, the fiber-reinforced resin composite material based on coordination dynamic network is obtained.

[0063] Further, the boron source in step S11 is phenylboronic acid. In another embodiment, the boron source in step S11 is a borate ester.

[0064] Furthermore, the stirring speed in step S11 is 500 rpm.

[0065] Further, in step S11, the dispersant is polyvinyl alcohol with a molecular weight of 25,000. In another embodiment, in step S11, the dispersant is polyvinyl alcohol with a molecular weight of 30,000. In yet another embodiment, in step S11, the dispersant is polyvinyl alcohol with a molecular weight of 35,000.

[0066] Further, the nanofiller mentioned in step S12 is nano-calcium carbonate. In another embodiment, the nanofiller mentioned in step S12 is a mixture of nano-silica, nano-silicon carbide and nano-calcium carbonate in a mass ratio of 1:2:2.

[0067] Furthermore, the stirring speed of the shearing and stirring in step S12 is 500 rpm.

[0068] Furthermore, the thermosetting resin in step S2 is an unsaturated polyester resin.

[0069] Furthermore, the stirring speed in step S2 is 500 rpm.

[0070] Furthermore, the fatty amine curing agent mentioned in step S31 is triethylenetetramine.

[0071] Furthermore, the stirring speed in step S31 is 400 rpm.

[0072] Furthermore, the fiber cloth mentioned in step 32 is carbon fiber cloth.

[0073] The fiber-reinforced resin composite material based on coordination dynamic network is prepared by any one of the methods described above.

[0074] Example 1 The preparation method of fiber-reinforced resin composites based on coordination dynamic networks includes the following steps: Step S1, Preparation of the composite dispersion: S11. Mix 10g of polyvinyl alcohol (dispersant, molecular weight 5000) with 1g of phenylboronic acid, and stir at 100℃ until the phenylboronic acid is completely dissolved and disappears to obtain a fluid; S12. Slowly add 35g of fumed silica (nanofiller) to the fluid and continuously shear and stir for 1 hour to obtain a paste-like composite dispersion. Step S2, Preparation of modified resin prepolymer: Add 306.7g of bisphenol A type epoxy resin (E51) to the composite dispersion obtained in step S12, and stir at 200rpm for 2 hours at 80°C to obtain the modified resin prepolymer. Step S3, Molding: S31. Mix the modified resin prepolymer obtained in step S2 with 70.5g of fatty amine curing agent, stir and disperse the mixture, and use a vacuum device to remove the air bubbles generated during the stirring process to obtain the resin to be cured. S32. The cut plain weave carbon fiber cloth is completely immersed in the resin to be cured obtained in step S31 for 30 minutes. The impregnated plain weave carbon fiber cloth is laid in layers in the mold by hand lay-up process. During the lay-up process, the fiber cloth is pressed to squeeze out the air bubbles, and a sample to be cured with 8 layers of plain weave carbon fiber cloth is obtained. Step S4, Curing: The sample to be cured obtained in step S3 is placed in an oven and hot-pressed at 1 MPa and 80°C for 5 hours. After demolding, the composite material laminate (i.e., fiber-reinforced resin composite material based on coordination dynamic network, denoted as DC-CFRP-1) is obtained.

[0075] Furthermore, the fatty amine curing agent mentioned in step S31 is triethylenetetramine.

[0076] Example 2 Similar to Example 1, except that the polyvinyl alcohol in Example 1 was replaced with an equal mass of hydroxyl-terminated polydimethylsiloxane, and other conditions remained unchanged, to prepare a composite laminate (DC-CFRP-2).

[0077] Comparative Example 1: Carbon fiber composite materials without dynamic network system The preparation method of the composite material includes the following steps: (1) Mix 306.7g of bisphenol A type epoxy resin (E51) with 70.5g of fatty amine curing agent, stir and disperse the mixture, and use a vacuum device to remove the air bubbles generated during the stirring process to obtain the resin to be cured. (2) The cut plain weave carbon fiber cloth is completely immersed in the resin to be cured obtained in step 1 for 30 minutes. The impregnated plain weave carbon fiber cloth is laid in the mold layer by layer using the hand lay-up process. During the lay-up process, the fiber cloth is pressed to squeeze out the air bubbles, and a sample to be cured with 8 layers of plain weave carbon fiber cloth is obtained. (3) Place the sample to be cured in an oven and heat-press it at 1MPa and 80℃ for 5 hours. After demolding, carbon fiber composite material (CFRP-Control) is obtained.

[0078] Compared with Example 1, no composite dispersion was added, and carbon fiber composite material (CFRP-Control) was prepared using only pure bisphenol A type epoxy resin (E51) and the same curing agent.

[0079] Performance testing The fiber-reinforced resin composites based on coordination dynamic networks obtained in Examples 1-2 and the carbon fiber composites prepared in the comparative example were subjected to testing and characterization of post-impact compressive strength, interfacial shear strength, simply supported beam impact strength, and flexural properties, respectively. The test of post-impact compressive strength shall be performed in accordance with the standard GB / T 21239-2022.

[0080] The interfacial shear strength was tested in accordance with the Q / SCU PAS22-2022 standard.

[0081] The impact strength test of simply supported beams shall be carried out in accordance with the GB / T229—2020 standard.

[0082] The bending performance test shall be performed in accordance with the GB / T 9341-2008 standard.

[0083] The specific test results are shown in Table 1-3. Table 1 Experimental results of interfacial shear strength Table 2 Impact strength and three-point bending test results of simply supported beams Table 3. Experimental results of compressive strength after impact. As can be seen from Tables 1-3, the fiber-reinforced resin composite material DC-CFRP-1 based on coordination dynamic network prepared in Example 1 exhibits excellent impact toughness and resistance to impact damage, as detailed below: (1) Post-impact compressive strength: Compared with CFRP-Control, the performance of the fiber-reinforced resin composite material DC-CFRP-1 based on coordination dynamic network prepared in Example 1 was improved by 39.67%; the performance of the fiber-reinforced resin composite material DC-CFRP-2 based on coordination dynamic network prepared in Example 2 was improved by 42.98%.

[0084] (2) Interfacial shear strength: Compared with CFRP-Control, the performance of the fiber-reinforced resin composite material DC-CFRP-1 based on coordination dynamic network prepared in Example 1 was improved by 160.57%; the performance of the fiber-reinforced resin composite material DC-CFRP-2 based on coordination dynamic network prepared in Example 2 was improved by 192.57%.

[0085] (3) Impact strength of simply supported beams: Compared with CFRP-Control, the performance of the fiber-reinforced resin composite material DC-CFRP-1 based on coordination dynamic network prepared in Example 1 was improved by 41.25%; the performance of the fiber-reinforced resin composite material DC-CFRP-2 based on coordination dynamic network prepared in Example 2 was improved by 36.32%. (4) Bending performance: Compared with CFRP-Control, the fiber-reinforced resin composite material DC-CFRP-1 based on coordination dynamic network prepared in Example 1 and the fiber-reinforced resin composite material DC-CFRP-2 based on coordination dynamic network prepared in Example 2 have basically the same performance.

[0086] The embodiments of the present invention have been described in detail above. However, the present invention is not limited to the above embodiments, and various changes can be made within the scope of knowledge possessed by those skilled in the art without departing from the spirit of the present invention.

Claims

1. A method for preparing fiber-reinforced resin composite materials based on coordination dynamic networks, characterized in that, The steps are as follows, based on parts by weight: Step S1, Preparation of the composite dispersion: S11. Add 1 part of boron source to 8 to 12 parts of dispersant, and stir at 90°C to 110°C until the boron source is completely lost to obtain a fluid. S12. Slowly add 35 to 40 parts of nanofiller to the fluid obtained in step S11, and continuously shear and stir for at least 1 hour. After completion, a uniform and stable composite dispersion is obtained. Step S2, Preparation of modified resin prepolymer: Add 90-110 parts of thermosetting resin to the composite dispersion obtained in step S12, and stir and pre-react at 40°C-120°C for at least 1 hour to obtain a modified resin prepolymer. Step S3, Molding: S31. The modified resin prepolymer obtained in step S2 is mixed with the fatty amine curing agent at a molar ratio of epoxy group to amine group of 1:0.95-1. After mixing, the mixture is stirred and dispersed, and the air bubbles generated during the stirring process are removed using a vacuum device to obtain the resin to be cured. S32. The cut fiber cloth is completely immersed in the resin to be cured obtained in step S31 for at least 20 minutes, and then it is laid in layers in the mold. During the layering process, the fiber cloth is pressed to squeeze out the air bubbles to obtain the sample to be cured. Step S4, Curing: The sample to be cured obtained in step S3 is placed in an oven and hot-pressed and cured at 1 MPa and 70℃~90℃ for 4~8 hours. After removal and demolding, the fiber-reinforced resin composite material based on coordination dynamic network is obtained.

2. The method for preparing fiber-reinforced resin composite materials based on coordination dynamic networks as described in claim 1, characterized in that, The boron source mentioned in step S11 is one of boric acid, phenylboronic acid, borate esters, and organoboranes, and / or The stirring speed in step S11 is 400-600 rpm, and / or Further, the dispersant mentioned in step S11 is one of polyethylene glycol, hydroxyl silicone oil, and polyvinyl alcohol.

3. The method for preparing fiber-reinforced resin composite materials based on coordination dynamic networks as described in claim 2, characterized in that, The organoborane has the general structural formula BR3, where R is a C1-C3 alkyl group, and / or The dispersant mentioned in step S11 is polyvinyl alcohol, and / or The polyethylene glycol has a molecular weight of 360–440, and / or The molecular weight of the polyvinyl alcohol is 25,000 to 35,000.

4. The method for preparing fiber-reinforced resin composite materials based on coordination dynamic networks as described in claim 1, characterized in that, The nanofiller mentioned in step S12 is one or more of nano-silica, nano-silicon carbide, and nano-calcium carbonate, and / or In step S12, the shearing and mixing speed is 400–600 rpm, and / or The thermosetting resin mentioned in step S2 is one of epoxy resin, phenolic resin, and unsaturated polyester resin.

5. The method for preparing fiber-reinforced resin composite materials based on coordination dynamic networks as described in claim 4, characterized in that, The nanofiller mentioned in step S12 is fumed silica nanoparticles, and / or The thermosetting resin mentioned in step S2 is epoxy resin.

6. The method for preparing fiber-reinforced resin composite materials based on coordination dynamic networks as described in claim 1, characterized in that, The stirring speed in step S2 is 400-600 rpm.

7. The method for preparing fiber-reinforced resin composite materials based on coordination dynamic networks as described in claim 1, characterized in that, The fatty amine curing agent mentioned in step S31 is one of triethylenetetramine and ethylenediamine.

8. The method for preparing fiber-reinforced resin composite materials based on coordination dynamic networks as described in claim 1, characterized in that, The stirring speed in step S31 is 300-500 rpm.

9. The method for preparing fiber-reinforced resin composite materials based on coordination dynamic networks as described in claim 1, characterized in that, The fiber cloth mentioned in step 32 is carbon fiber cloth or polyimide fiber cloth.

10. A fiber-reinforced resin composite material based on a coordination dynamic network, characterized in that, Prepared by the method described in any one of claims 1-9.

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