Multi-base reinforced composite material and preparation method thereof
By combining bio-fiber fabric layers and carbon fiber fabric layers with tungsten wire mesh and modified dioxazoline solution, the problems of poor bonding force and insufficient mechanical properties between bio-fiber and resin are solved, resulting in a high-strength, high-shield biodegradable composite material that can meet various process requirements.
Patent Information
- Application Number
- CN202511694820.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-18
- Publication Date
- 2026-01-13
AI Technical Summary
Existing resin-based composite materials have shortcomings in terms of environmental protection and material compatibility, especially the poor bonding force between bio-fibers and resins, and their mechanical properties need to be improved.
The material employs a composite of bio-fiber fabric layers and carbon fiber fabric layers, introduces a tungsten wire mesh layer and modifies it with resin, combines appropriate layup design, and impregnates the yarn with a modified dioxazoline solution to optimize the material's mechanical and shielding properties.
It improves the mechanical strength and shielding performance of composite materials, realizes the biodegradability of biofibers and the electromagnetic shielding effect of multilayer tungsten wire mesh, adapts to various process requirements, and provides a direction for the upgrading and iteration of green materials.
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Figure CN121316342A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to a multi-base reinforced composite material and its preparation method, belonging to the field of polymer materials technology. Background Technology
[0002] Since composite materials first appeared in the construction field in the 18th century, their development has spanned over 200 years, especially resin-based composites, whose raw materials are mainly petroleum derivatives or energy-intensive minerals. To meet the needs of environmental protection and social development, the applicant has developed a bio-based and biodegradable composite material. This material reduces carbon emissions while also solving the problem of incompatibility between bio-fibers and the resins used, improving the interfacial bonding between different materials and enhancing the product's mechanical properties. Summary of the Invention
[0003] This invention provides a multi-base reinforced composite material and its preparation method. By modifying the yarn, introducing tungsten wire mesh, and treating the surface of carbon fibers, the mechanical strength and shielding performance of the composite material are significantly improved, realizing the possibility of making composite materials using bio-fibers. Furthermore, the mechanical properties of the composite material are optimized through appropriate layup design.
[0004] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: A multi-base reinforced composite material is formed by resin compositing at least a bio-fiber fabric layer and a carbon fiber fabric layer, or by resin compositing at least a bio-fiber fabric layer, a carbon fiber fabric layer and a tungsten wire mesh layer. The tungsten wire mesh layer is composited between the bio-fiber fabric layers, or between the bio-fiber fabric layers and the carbon fiber fabric layers. The tungsten wire used in the tungsten wire mesh has a fineness of 10-30 micrometers. The tungsten wire mesh is woven in a (0°+90°) or ±45° manner. During use, the tungsten wire mesh can be laid up in various ways according to product requirements. The yarn used in the bio-fiber fabric is a blended yarn, which is impregnated and modified with a modified dioxazoline solution with a mass concentration of 0.1%-5%. The modified dioxazoline is prepared by modifying 1,3-bis(2-oxazolinyl)benzene (MPBO) and 2,2'-bis(2-oxazoline) with epoxy resin and / or polyurethane. The mass ratio of 1,3-bis(2-oxazolinyl)benzene (MPBO) to 2,2'-bis(2-oxazoline) is 1:(0.5~1).
[0005] The resins used in the preparation of composite materials include thermosetting resins and thermoplastic resins. Thermosetting resins mainly include epoxy resins, polyurethane resins, unsaturated resins, dicyclopentadiene resins, and vinyl resins, etc.; thermoplastic resins mainly include polyethylene, polypropylene, nylon, polyvinyl chloride, polystyrene, PMMA, PET, etc.
[0006] The multi-base reinforced composite material of this application has the characteristics of being lightweight, high-strength, high-toughness, and high-shielding.
[0007] To balance the mechanical and shielding properties of the material, the above method for preparing modified dioxazoline by epoxy resin modification is as follows: S-propylene oxide or allyl ethylene oxide, or S-propylene oxide and allyl ethylene oxide sequentially, are reacted with dioxazoline. After reaching a number-average molecular weight of 2000-5000 Da through nucleophilic addition reaction, the reaction is terminated to obtain modified dioxazoline; wherein, the dioxazoline mixture is a mixture of 1,3-bis(2-oxazolinyl)benzene (MPBO) and 2,2'-bis(2-oxazoline) in a mass ratio of 1:(0.5~1).
[0008] As a specific implementation scheme, the method for preparing modified dioxazoline by epoxy resin modification is as follows: a mixture of dioxazoline is added to anhydrous DMF (N,N-dimethylformamide), stirred and heated to 50~60℃, kept at this temperature for 20~30 min to completely dissolve the solid, a catalyst is added, S-propylene oxide is added dropwise, after the addition is complete, the reaction is carried out at 50~60℃ for 2~3 h, and / or allyl ethylene oxide is added dropwise, after the addition is complete, the reaction is carried out at 50~60℃ for 3~4 h, DMF is removed by vacuum distillation, and the mixture is dried (dried at 60℃ for 4 h) to obtain modified dioxazoline; The catalyst is a complex of CuI, 3,3'-methylenebis(5-methyloxazoline) and 1-butyl-3-methylimidazolium tetrafluoroborate in a molar ratio of 1:(1~1.2):(0.3~0.6).
[0009] The reaction process was monitored using GPC, and the reaction was stopped when the molecular weight reached the specified requirement.
[0010] To improve reaction selectivity and catalytic efficiency, the above-mentioned CuI composite catalyst can achieve efficient conversion at lower temperatures, reduce reaction temperature, and decrease side reactions.
[0011] The mass amount of the above catalyst is 0.5~1.5% of the mass of the dioxazoline mixture; the mass-to-volume ratio of the dioxazoline mixture to anhydrous DMF is 1g:(4~5)mL; the molar ratio of the dioxazoline mixture, S-propylene oxide and allyl ethylene oxide is 1:(1.5~2.5):(1~2).
[0012] To balance the mechanical properties and shielding performance of the material, the above method for preparing modified dioxazoline through polyurethane modification is as follows: MDI was added to anhydrous ethyl acetate, stirred, and heated to 55-65°C. The mixture was kept at this temperature for 20-30 minutes to ensure complete dissolution of the MDI. Then, a zinc-based catalyst was added, and the mixture was stirred for 5-10 minutes (the solution turned pale yellow-green). A solution of ethyl acetate containing TMP was added dropwise. After the addition was complete, the mixture was reacted at 55-65°C for 1-2 hours. Next, a solution of ethyl acetate containing DMBA was added dropwise. After the addition was complete, the mixture was reacted at 60-70°C for 3-4 hours. Then, a mixture of dioxazoline was added, and the mixture was reacted at 60-70°C for 1-1.5 hours. The mixture was then distilled under reduced pressure and dried (at 60°C for 6 hours) to obtain the modified dioxazoline. The dioxazoline mixture is a mixture of 1,3-bis(2-oxazolinyl)benzene (MPBO) and 2,2'-bis(2-oxazoline) in a mass ratio of 1:(0.5~1).
[0013] During the above reaction process, the reaction progress can be monitored by FTIR. In step B1, when the intensity of the -NCO peak (2270 cm⁻¹) in the FTIR drops to 65±3% of the initial value, step B2 is carried out. In step B2, when the intensity of the -NCO peak drops to 20±2% of the initial value, the reaction is terminated.
[0014] The modified dioxazoline was prepared by synergistic chain extension of MDI with trimethylolpropane (TMP) and dimethylolbutyric acid (DMBA) to precisely control the branching degree and carboxyl content of the modified MDI (4,4'-diphenylmethane diisocyanate), and then reacting it with MPBO and 2,2'-bis(2-oxazoline).
[0015] Unless otherwise specified, the dripping rate in this application is 30-60 drops / min.
[0016] To ensure catalytic performance, the zinc-based catalyst is a mixture of zinc acetylacetonate and triethylamine in a molar ratio of 1:2, and the mass of the zinc-based catalyst is 1 to 2% of the mass of the dioxazoline mixture.
[0017] The above-mentioned ethyl acetate solution of TMP is prepared by mixing TMP and an equal mass of ethyl acetate; the ethyl acetate solution of DMBA is prepared by mixing DMBA and ethyl acetate in a mass ratio of 1:2; the molar ratio of the mixture of MDI, TMP, DMBA and dioxazoline is 5:1:(1.5~2):(5~6).
[0018] When the modified dioxazoline is prepared by modification with epoxy resin, the solvent used for the modified dioxazoline solution is m-cresol. The specific preparation method is as follows: the modified dioxazoline is slowly poured into the m-cresol solvent at high temperature and in a molten state, while stirring, to prepare a m-cresol solution.
[0019] When the modified dioxazoline is prepared through polyurethane modification, the solvent used for the modified dioxazoline solution is ethyl acetate. Since the polyurethane-modified dioxazoline is prepared in an ethyl acetate solution, the solvent can be directly diluted to the desired concentration without removing the dioxazoline during preparation. Alternatively, the solution can be dissolved using a solvent if necessary.
[0020] Because of the low fineness of the tungsten wire used, the mesh size of the woven tungsten wire mesh can be smaller and the mesh count can be higher (800-1500 mesh). In addition, the overlapping of multiple layers of tungsten wire mesh and the misalignment of the mesh size result in a better electromagnetic shielding effect.
[0021] The above-mentioned blended yarn is formed by blending 30%-80% bamboo fiber, 10-30% hemp and cotton fiber and the balance polylactic acid fiber, wherein the hemp fiber includes flax fiber, sisal fiber and / or ramie fiber.
[0022] The preparation method of the above-mentioned multi-molecular reinforced composite material includes the following steps: 1) Produced by blending, 30%-80% bamboo fiber, 10-30% hemp fiber and the balance polylactic acid fiber are blended into yarn and wound into tubes. The hemp fiber includes flax, sisal and / or ramie fiber, etc. 2) The yarn obtained in step 1) is sequentially unwound, first impregnated, sizing, and second impregnated, then homogenized, dried, and shaped, and finally wound up for later use; wherein, the sizing agent used for the first and second impregnations is a modified dioxazoline solution with a mass concentration of 0.1%-5%; the modified dioxazoline is prepared by modifying 1,3-bis(2-oxazolinyl)benzene (MPBO) and 2,2'-bis(2-oxazoline) with epoxy resin and / or polyurethane, and the mass ratio of 1,3-bis(2-oxazolinyl)benzene (MPBO) to 2,2'-bis(2-oxazoline) is 1:(0 .5~1) In this step, one end of the yarn is wound up and the other end is unwound, which realizes the continuous modification of the yarn; after the first impregnation, the sizing can improve the permeability and remove the excess solution on the surface by squeezing, while loosening the internal structure of the yarn, which is conducive to better permeation of the yarn during the second impregnation; the homogenization process is the process of homogenizing the surface liquid layer. During the movement of the yarn, there is a vertical line process in the homogenization section. Using the effect of gravity, the surface liquid is allowed to flow freely, while removing the excess liquid and drying. After the solvent in the solution evaporates, a very thin film layer is formed on the surface of the yarn. 3) Prepare bio-fiber fabrics from the yarn obtained in step 2) by means of machine weaving, knitting or woven fabric; 4) Lay up bio-fiber fabric and carbon fiber fabric, or lay up bio-fiber fabric, carbon fiber fabric and tungsten wire mesh, wherein the tungsten wire mesh is located between the fiber fabric layers, and then prepare composite materials by pultrusion, vacuum infusion or molding, etc., or make the fabric into prepreg and then prepare composite materials by autoclave, oven curing, etc.
[0023] The aforementioned carbon fiber fabrics can be purchased directly from existing commercially available products, such as warp-knitted triaxial fabrics, twill fabrics, or checkered fabrics, with a weight of 300~800 g / m². 2 .
[0024] To improve uniformity, the base-reinforced composite material of this application has a symmetrical structure.
[0025] As one of the preferred implementations, the base-reinforced composite material is composed of (±45°) carbon fibers, 0° bio-fiber unidirectional fabric, (±45°) carbon fibers, 90° bio-fiber unidirectional fabric, and (±45°) carbon fibers arranged sequentially from top to bottom.
[0026] Alternatively, the base-reinforced composite material is composed of (±45°) carbon fibers, (0°90°) bio-fibers, (±45°) tungsten wire mesh, (0°90°) bio-fibers and (±45°) carbon fibers arranged sequentially from top to bottom.
[0027] Alternatively, the base-reinforced composite material is composed of (±45°) carbon fibers, 0° bio-fiber unidirectional fabric, (±45°) tungsten wire mesh, 90° bio-fiber unidirectional fabric and (±45°) carbon fibers arranged sequentially from top to bottom.
[0028] Alternatively, the base-reinforced composite material is composed of (0°90°) bio-fibers, (±45°) tungsten wire mesh, (0°90°) carbon fibers, (±45°) tungsten wire mesh, and (0°90°) bio-fibers arranged sequentially from top to bottom.
[0029] Of course, existing nickel plating methods can also be used to further enhance the electromagnetic shielding effect.
[0030] Unless otherwise specified, all percentages in this application are percentages by mass.
[0031] Any techniques not mentioned in this invention are based on existing technologies.
[0032] Compared with the prior art, the present invention has the following beneficial effects: 1) The use of bio-based fibers to prepare composite materials improves the recyclability and biodegradability of composite materials, provides direction for the upgrading and iteration of composite materials, reduces the amount of difficult-to-recycle fibers, and contributes to green materials, energy conservation and emission reduction. 2) By modifying the yarn, the mechanical properties and shielding performance of the composite material were significantly improved; 3) Tungsten wire mesh was added to the layup structure to increase the impact resistance of the composite material and to give the composite material studied better electromagnetic shielding function; it made up for the relatively poor impact strength of biological fibers and improved the impact strength of the final composite material. 4) The materials used can be adapted to various processes, and the layup structure can be optimized as needed to give the materials different properties and suitability for different applications; 5) Technological breakthroughs have been achieved in the application of bio-fibers, experience has been provided, and the practical application of bio-fibers has been promoted. Attached Figure Description
[0033] Figure 1 This is a flowchart illustrating the preparation process of the multi-base reinforced composite material of the present invention; Figure 2 This is a schematic diagram of the structure of the multi-base reinforced composite material used in Example 1 of the present invention; Figure 3 This is a schematic diagram of the structure of the multi-base reinforced composite material in Example 2 of the present invention; Figure 4 This is a schematic diagram of the structure of the multi-base reinforced composite material in Example 4 of the present invention; Figure 5 This is a schematic diagram of the structure of the multi-base reinforced composite material used in Example 5 of the present invention. Detailed Implementation
[0034] To better understand the present invention, the following embodiments further illustrate the content of the present invention, but the content of the present invention is not limited to the following embodiments.
[0035] Unless otherwise specified, all examples were performed at room temperature (15~25℃); unless otherwise specified, the stirring speed was 200 r / min; unless otherwise specified, the dropping speed was 45 drops / min.
[0036] Example 1
[0037] Modified dioxazoline was prepared by epoxy resin modification: 100 g (0.463 mol) of 1,3-bis(2-oxazolinyl)benzene (MPBO) and 75 g (0.543 mol) of 2,2'-bis(2-oxazolin) were added to 800 mL of anhydrous DMF (N,N-dimethylformamide), stirred, and heated to 55 °C for 20 min. Then, 1.75 g of catalyst (0.7 g of CuI, 0.7 g of 3,3'-methylenebis(5-methyloxazolin) and 0.35 g of 1-butyl-3-methylimidazolium tetrafluoroborate) were added dropwise (30 drops / min). After the addition was complete, the reaction was allowed to proceed at 55 °C for 2.5 h. Finally, 126.18 g (1.5 mol) of allyl ethylene oxide was added dropwise (45 drops / min). After the reaction was completed, the reaction was carried out at 55℃ for 3 hours, DMF was removed by vacuum distillation, and the product was dried (dried at 60℃ for 4 hours) to obtain the modified dioxazoline.
[0038] Example 2
[0039] The difference from Example 1 is that allyl ethylene oxide was replaced with an equimolar amount of S-propylene oxide, while all other aspects were the same as in Example 1, resulting in modified dioxazoline.
[0040] Example 3
[0041] The difference from Example 1 is that S-propylene oxide was replaced with an equimolar amount of allyl ethylene oxide, while all other aspects were the same as in Example 1, resulting in modified dioxazoline.
[0042] Comparative Example 1 The difference from Example 1 is that the catalyst used was 1.75g CuI, while the rest were the same as in Example 1.
[0043] Comparative Example 2 The difference from Example 1 is that the catalyst used was 1.75 g (a mixture of CuI and 3,3'-methylenebis(5-methyloxazoline) in a mass ratio of 1:1), and the rest was the same as in Example 1.
[0044] Comparative Example 3 The difference from Example 1 is that the catalyst used was 1.75 g (a mixture of CuI and 1-butyl-3-methylimidazolium tetrafluoroborate in a mass ratio of 1:0.5), and the rest was the same as in Example 1.
[0045] Comparative Example 4 The difference from Example 1 is that 1,3-bis(2-oxazolinyl)benzene (MPBO) was replaced with an equimolar amount of 2,2'-bis(2-oxazoline), while all other aspects were the same as in Example 1.
[0046] Comparative Example 5 The difference from Example 1 is that 2,2'-bis(2-oxazoline) was replaced with an equimolar amount of 1,3-bis(2-oxazoline)benzene (MPBO), while all other aspects were the same as in Example 1.
[0047] The modified dioxazoline solution in Examples 1-3 and Comparative Examples 1-5 was prepared by slowly pouring the modified dioxazoline into m-cresol solvent at high temperature and in a molten state while stirring, to prepare a modified dioxazoline m-cresol solution with a mass concentration of 1%.
[0048] Example 4
[0049] Modified dioxazoline was prepared by polyurethane modification: Add 250.26g of MDI to 300g of anhydrous ethyl acetate, stir and heat to 60℃, maintain this temperature for 20min; then add 1.78g of zinc-based catalyst (a mixture of zinc acetylacetonate and triethylamine in a molar ratio of 1:2), stir for 5-10min (the solution turns pale yellow-green), then add dropwise a solution of ethyl acetate containing TMP (24.56g TMP and 24.56g ethyl acetate). After the addition is complete, react at 60℃ for 1h; then add dropwise a solution of ethyl acetate containing DMBA (48.74g DMBA and 97.48g ethyl acetate). After the addition is complete, react at 60℃ for 3h, then add 100g (0.463mol) of 1,3-bis(2-oxazolinyl)benzene (MPBO) and 75g (0.543mol) of 2,2'-bis(2-oxazoline), and react at 65℃ for 1 hour. h, to obtain modified dioxazoline, then diluted with anhydrous ethyl acetate to a solid content of 1%, to obtain a modified dioxazoline solution.
[0050] Example 5
[0051] The difference from Example 4 is that DMBA was replaced with an equimolar amount of TMP, while all other steps were the same as in Example 4, to obtain a modified dioxazoline solution.
[0052] Example 6
[0053] The difference from Example 4 is that TMP was replaced with an equimolar amount of DMBA, while all other aspects were the same as in Example 4, to obtain a modified dioxazoline solution.
[0054] Comparative Example 6 The difference from Example 4 is that the catalyst used was 1.78g of zinc acetylacetonate, and the rest were the same as in Example 4.
[0055] Application Example 1 1) The yarn is produced by blending bamboo fiber (REBOOCEL® regenerated bamboo fiber, 0.89 dtex × 38mm, Jilin Chemical Fiber Group) 50%, sisal fiber (Guangxi Sisal Group Co., Ltd., Dongyi No. 1 sisal, fiber length 90-120cm) 30%, and polylactic acid fiber (REVODE 711, Zhejiang Haizheng Biomaterials) 20% into yarn (29Tex) and then wound into tubes; 2) The yarn obtained in step 1) is successively unwound, first impregnated, sizing (pressed by rollers with a gap of 1 / 3 of the yarn fineness), and second impregnated, then homogenized, dried and shaped (held at 40℃ for 1 hour, then heated to 80℃ and held for 1 hour), and finally wound up for use; wherein, the sizing agent used for the first and second impregnation is a modified dioxazoline solution with a mass concentration of 1% and fully impregnated for 10 minutes; 3) The yarns obtained in step 2) are then woven into biaxial bio-fiber fabrics (200 g / m²). 2 ); 4) Incorporate bio-fiber fabrics and carbon fiber fabrics (twill fabric, 300g / m²) 2 After the carbon fiber and non-woven fabrics are stacked according to the layup scheme, the bag film is laid, then a vacuum is drawn, and epoxy resin (E-51, curing agent 593) is introduced. The layup scheme is as follows from top to bottom: (±45°) carbon fiber fabric layer, (0° 90°) bio-fiber fabric layer, tungsten wire mesh layer (the tungsten wire used is 20 microns fine, woven in a ±45° manner, 800 mesh), (0° 90°) bio-fiber fabric layer and (±45°) carbon fiber fabric layer. The vacuum is drawn to a negative pressure of one atmosphere, and cured at 90°C for 8 hours to obtain the composite material.
[0056] Step 2) The performance evaluation of the composite materials is shown in Table 1, using the modified dioxazoline solutions obtained in each example.
[0057] Table 1
[0058] Application Example 2 Unlike Application Example 1, in step 4), the composite material layup, from top to bottom, is as follows: (±45°) carbon fiber fabric layer, (0°) bio-fiber fabric layer, (±45°) bio-fiber fabric layer, (90°) bio-fiber fabric layer, and (±45°) carbon fiber fabric layer. This example uses the modified dioxazoline m-cresol solution obtained in Example 1. All other steps are the same as in Application Example 1.
[0059] Application Example 3 The difference from Application Example 1 is that in step 1), the blended yarn contains 45% bamboo fiber, 30% sisal fiber, and 25% polylactic acid fiber. This example uses the modified dioxazoline m-cresol solution obtained in Example 1. All other aspects are the same as in Application Example 1.
[0060] Application Example 4 Unlike Application Example 1, in step 4), the composite material layers, from top to bottom, are: (0° 90°) bio-cellulose fabric layer, (±45°) tungsten wire mesh layer, (0° 90°) carbon fiber fabric layer, (±45°) tungsten wire mesh layer, and (0° 90°) bio-cellulose fabric layer. This example uses the modified dioxazoline m-cresol solution obtained in Example 1. All other steps are the same as in Application Example 1.
[0061] Application Example 5 Unlike Application Example 1, in step 4), the composite material layup, from top to bottom, is as follows: (0° 90°) nickel-plated carbon fiber fabric layer (Jinyuan (Shenzhen) Technology Co., Ltd., model: XJY-3k-300, 300g / m²), (±45°) tungsten wire mesh layer, (0° 90°) bio-fiber fabric layer, (±45°) tungsten wire mesh layer, and (0° 90°) nickel-plated carbon fiber fabric layer. This example uses the modified dioxazoline m-cresol solution obtained in Example 1. All other steps are the same as in Application Example 1.
[0062] Comparison Application Example 1 The difference from Application Example 1 is that step 2 is omitted, and the rest are the same as Application Example 1.
[0063] Comparative Application Example 2 The difference from Application Example 1 is that step 2) uses an unmodified dioxazoline solution with a mass concentration of 1% (the solvent is m-cresol, and the dioxazoline is 1,3-bis(2-oxazolinyl)benzene (MPBO) and 2,2'-bis(2-oxazoline) in a mass ratio of 100:75), while the rest is the same as in Application Example 1.
[0064] The performance evaluation of each application example is shown in Table 2. The data of application example 1 in Table 2 are the performance data of the composite material prepared using the modified dioxazoline m-cresol solution obtained in Example 1.
[0065] Table 2
Claims
1. A multi-molecular reinforced composite material, characterized in that: It is composed of at least a bio-fiber fabric layer and a carbon fiber fabric layer using resin composite, or at least a bio-fiber fabric layer, a carbon fiber fabric layer and a tungsten wire mesh layer using resin composite; The tungsten wire mesh layer is composited between the bio-fiber fabric layers, or between the bio-fiber fabric layers and the carbon fiber fabric layers; the tungsten wire used in the tungsten wire mesh has a fineness of 10-30 micrometers, and the tungsten wire mesh is woven in a (0°+90°) or ±45° manner. The yarn used in the bio-fiber fabric is a blended yarn, which is modified by impregnation with a modified dioxazoline solution with a mass concentration of 0.1%-5%. The modified dioxazoline is prepared by modifying 1,3-bis(2-oxazolinyl)benzene and 2,2'-bis(2-oxazoline) with epoxy resin and / or polyurethane, wherein the mass ratio of 1,3-bis(2-oxazolinyl)benzene to 2,2'-bis(2-oxazoline) is 1:(0.5~1).
2. The multi-fiber reinforced composite material according to claim 1, characterized in that: The method for preparing modified dioxazoline by epoxy resin modification is as follows: S-propylene oxide or allyl ethylene oxide, or S-propylene oxide and allyl ethylene oxide sequentially, are reacted with dioxazoline. After reaching a number average molecular weight of 2000-5000 Da through nucleophilic addition reaction, the reaction is terminated to obtain modified dioxazoline; wherein, the dioxazoline mixture is a mixture of 1,3-bis(2-oxazolinyl)benzene (MPBO) and 2,2'-bis(2-oxazoline) in a mass ratio of 1:(0.5~1).
3. The multi-molecular reinforced composite material according to claim 2, characterized in that: The method for preparing modified dioxazoline by epoxy resin modification is as follows: a mixture of dioxazoline is added to anhydrous DMF, stirred and heated to 50-60℃, kept at this temperature for 20-30 min, a catalyst is added, S-propylene oxide is added dropwise, after the addition is complete, the reaction is carried out at 50-60℃ for 2-3 h, and / or allyl ethylene oxide is added dropwise, after the addition is complete, the reaction is carried out at 50-60℃ for 3-4 h, DMF is removed by vacuum distillation, and the product is dried to obtain modified dioxazoline; The catalyst is a complex of CuI, 3,3'-methylenebis(5-methyloxazoline) and 1-butyl-3-methylimidazolium tetrafluoroborate in a molar ratio of 1:(1~1.2):(0.3~0.6).
4. The multi-molecular reinforced composite material according to claim 3, characterized in that: The mass of the catalyst is 0.5-1.5% of the mass of the dioxazoline mixture; the mass-to-volume ratio of the dioxazoline mixture to anhydrous DMF is 1 g: (4-5) mL; the molar ratio of the dioxazoline mixture, S-propylene oxide and allyl ethylene oxide is 1: (1.5-2.5): (1-2).
5. The multi-molecular reinforced composite material according to any one of claims 1-3, characterized in that: The method for preparing modified dioxazoline by polyurethane modification is as follows: MDI was added to anhydrous ethyl acetate, stirred and heated to 55-65℃, and kept at that temperature for 20-30 min. Then, a zinc-based catalyst was added, and the mixture was stirred for 5-10 min. A solution of ethyl acetate containing TMP was added dropwise. After the addition was complete, the mixture was reacted at 55-65℃ for 1-2 h. Then, a solution of ethyl acetate containing DMBA was added dropwise. After the addition was complete, the mixture was reacted at 60-70℃ for 3-4 h. Then, a mixture of dioxazoline was added, and the mixture was reacted at 60-70℃ for 1-1.5 h. The mixture was then distilled under reduced pressure and dried to obtain modified dioxazoline. The dioxazoline mixture is a mixture of 1,3-bis(2-oxazolinyl)benzene and 2,2'-bis(2-oxazoline) in a mass ratio of 1:(0.5~1).
6. The multi-molecular reinforced composite material according to claim 5, characterized in that: The zinc-based catalyst is a mixture of zinc acetylacetonate and triethylamine in a molar ratio of 1:2, and the mass of the zinc-based catalyst is 1 to 2% of the mass of the dioxazoline mixture.
7. The multi-molecular reinforced composite material according to claim 5, characterized in that: The ethyl acetate solution of TMP is prepared by mixing TMP and an equal mass of ethyl acetate; the ethyl acetate solution of DMBA is prepared by mixing DMBA and ethyl acetate in a mass ratio of 1:2; the molar ratio of the mixture of MDI, TMP, DMBA and dioxazoline is 5:1:(1.5~2):(5~6).
8. The multi-molecular reinforced composite material according to any one of claims 1-3, characterized in that: When the modified dioxazoline is prepared by modification with epoxy resin, the solvent used in the modified dioxazoline solution is m-cresol. When the modified dioxazoline is prepared by polyurethane modification, the solvent used for the modified dioxazoline solution is ethyl acetate.
9. The multi-molecular reinforced composite material according to any one of claims 1-3, characterized in that: The blended yarn is formed by blending 30%-80% bamboo fiber, 10-30% hemp and cotton fiber and the balance polylactic acid fiber, wherein the hemp fiber includes flax fiber, sisal fiber and / or ramie fiber.
10. A method for preparing a multi-molecular reinforced composite material according to any one of claims 1-9, characterized in that: Includes the following steps: 1) Produced by blending, 30%-80% bamboo fiber, 10-30% hemp fiber and the balance polylactic acid fiber are blended into yarn and wound into tubes, wherein the hemp fiber includes flax, sisal and / or ramie fiber; 2) The yarn obtained in step 1) is sequentially unwound, impregnated once, sizing, and impregnated twice, then homogenized, dried, and shaped, and finally wound up for use; wherein, the sizing agent used for the first and second impregnation is a modified dioxazoline solution with a mass concentration of 0.1%-5%; the modified dioxazoline is prepared by modifying 1,3-bis(2-oxazolinyl)benzene and 2,2'-bis(2-oxazoline) with epoxy resin and / or polyurethane, and the mass ratio of 1,3-bis(2-oxazolinyl)benzene to 2,2'-bis(2-oxazoline) is 1:(0.5~1); 3) Prepare bio-fiber fabrics from the yarn obtained in step 2) by weaving, knitting or woven methods respectively; 4) Lay up bio-fiber fabric and carbon fiber fabric, or lay up bio-fiber fabric, carbon fiber fabric and tungsten wire mesh, wherein the tungsten wire mesh is located between the fiber fabric layers, and then prepare a composite material by pultrusion, vacuum infusion or compression molding, or make the fabric into a prepreg and then prepare a composite material by autoclave or oven curing.