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WO2023155285A1 - 一种长-短碳纳米管增强增韧纤维复合材料及其制备方法 - Google Patents

一种长-短碳纳米管增强增韧纤维复合材料及其制备方法 Download PDF

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WO2023155285A1
WO2023155285A1 PCT/CN2022/086505 CN2022086505W WO2023155285A1 WO 2023155285 A1 WO2023155285 A1 WO 2023155285A1 CN 2022086505 W CN2022086505 W CN 2022086505W WO 2023155285 A1 WO2023155285 A1 WO 2023155285A1
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fiber cloth
carbon nanotubes
fiber
long
resin
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English (en)
French (fr)
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欧云福
祝令状
王梦杰
吴龙强
茅东升
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中国科学院宁波材料技术与工程研究所
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Publication of WO2023155285A1 publication Critical patent/WO2023155285A1/zh

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    • C—CHEMISTRY; METALLURGY
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    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J5/00—Manufacture of articles or shaped materials containing macromolecular substances
    • C08J5/04—Reinforcing macromolecular compounds with loose or coherent fibrous material
    • C08J5/0405—Reinforcing macromolecular compounds with loose or coherent fibrous material with inorganic fibres
    • C08J5/042—Reinforcing macromolecular compounds with loose or coherent fibrous material with inorganic fibres with carbon fibres
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J5/00—Manufacture of articles or shaped materials containing macromolecular substances
    • C08J5/005—Reinforced macromolecular compounds with nanosized materials, e.g. nanoparticles, nanofibres, nanotubes, nanowires, nanorods or nanolayered materials
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J5/00—Manufacture of articles or shaped materials containing macromolecular substances
    • C08J5/04—Reinforcing macromolecular compounds with loose or coherent fibrous material
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J5/00—Manufacture of articles or shaped materials containing macromolecular substances
    • C08J5/04—Reinforcing macromolecular compounds with loose or coherent fibrous material
    • C08J5/0405—Reinforcing macromolecular compounds with loose or coherent fibrous material with inorganic fibres
    • C08J5/043—Reinforcing macromolecular compounds with loose or coherent fibrous material with inorganic fibres with glass fibres
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
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    • C08J5/00—Manufacture of articles or shaped materials containing macromolecular substances
    • C08J5/04—Reinforcing macromolecular compounds with loose or coherent fibrous material
    • C08J5/046—Reinforcing macromolecular compounds with loose or coherent fibrous material with synthetic macromolecular fibrous material
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
    • C08K3/00—Use of inorganic substances as compounding ingredients
    • C08K3/02—Elements
    • C08K3/04—Carbon
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
    • C08K7/00—Use of ingredients characterised by shape
    • C08K7/02—Fibres or whiskers
    • C08K7/04—Fibres or whiskers inorganic
    • C08K7/06—Elements
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
    • C08K9/00—Use of pretreated ingredients
    • C08K9/02—Ingredients treated with inorganic substances
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
    • C08K9/00—Use of pretreated ingredients
    • C08K9/04—Ingredients treated with organic substances
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
    • C08L63/00—Compositions of epoxy resins; Compositions of derivatives of epoxy resins
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J2363/00—Characterised by the use of epoxy resins; Derivatives of epoxy resins
    • C08J2363/02—Polyglycidyl ethers of bis-phenols
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
    • C08K2201/00—Specific properties of additives
    • C08K2201/002—Physical properties
    • C08K2201/004—Additives being defined by their length
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
    • C08K2201/00—Specific properties of additives
    • C08K2201/011—Nanostructured additives
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
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    • C08K3/00—Use of inorganic substances as compounding ingredients
    • C08K3/02—Elements
    • C08K3/04—Carbon
    • C08K3/041—Carbon nanotubes
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T50/00—Aeronautics or air transport
    • Y02T50/40—Weight reduction

Definitions

  • the invention relates to the field of composite materials, in particular to a long-short carbon nanotube reinforced and toughened fiber composite material and a preparation method thereof.
  • Fig. 1 is the schematic diagram of the cross-section of carbon fiber epoxy resin composite material, assuming that the diameter of carbon fiber is 7 microns (such as T700 carbon fiber produced by Toray, Japan), and its volume fraction in composite material is 55%; In the epoxy matrix, the distance between adjacent carbon fibers is less than 2 microns.
  • fiber composite materials are usually used in the form of laminated products. Due to the influence of their hierarchical structure characteristics and the intrinsic brittleness of the resin matrix, their bearing capacity along the thickness direction is low, and the loads such as in-plane compression, bending, fatigue and transverse impact Under the action, delamination damage is prone to occur. Once delamination starts and propagates inside the laminate, the stiffness of the entire structure will gradually decrease, eventually leading to catastrophic failure. Therefore, improving their interlaminar fracture toughness is crucial in many engineering applications.
  • the object of the present invention is to provide a long-short carbon nanotube reinforced toughened fiber composite material and a preparation method thereof.
  • the long-short carbon nanotube reinforced and toughened fiber composite material provided by the invention can simultaneously realize matrix reinforcement and interlayer toughening of the composite material.
  • the invention provides a method for preparing a long-short carbon nanotube reinforced and toughened fiber composite material, comprising the following steps:
  • the fiber preform includes successively laminated and contacted: an upper fiber cloth layer, a long carbon nanotube fiber yarn layer, and a lower fiber cloth layer;
  • the long carbon nanotube fiber yarn layer is a yarn-like structure formed by long carbon nanotubes
  • the length of the short carbon nanotubes is 0.5-3 ⁇ m, and the average length is ⁇ 2 ⁇ m;
  • the length of the long carbon nanotubes is 50-1000 ⁇ m.
  • the short carbon nanotubes are non-surface-modified short carbon nanotubes or surface-modified short carbon nanotubes
  • the long carbon nanotubes are long carbon nanotubes without surface modification or long carbon nanotubes with surface modification;
  • the surface modification functional group is selected from one or more of amino, carboxyl and carbonyl;
  • the surface-modifying functional group is selected from one or more of amino, carboxyl and carbonyl.
  • thermosetting resin includes one or more of epoxy resin, polyester resin, phenolic resin, vinyl resin and bismaleimide resin.
  • the mass of the short carbon nanotubes is 0.1% to 5% of the mass of the thermosetting resin
  • the mass of the long carbon nanotubes is 0.1% to 5% of the mass of the thermosetting resin
  • the mass percentage of the total mass of the upper fiber cloth and the lower fiber cloth in the composite material is 40%-80%.
  • the fiber cloth in the upper fiber cloth layer is unidirectional fiber weaving or multidirectional fiber weaving;
  • the fiber cloth in the lower fiber cloth layer is unidirectional fiber weaving or multidirectional fiber weaving;
  • the fiber cloth in the upper fiber cloth layer is continuous carbon fiber cloth, continuous glass fiber cloth or continuous aramid fiber cloth;
  • the fiber cloth in the lower fiber cloth layer is continuous carbon fiber cloth, continuous glass fiber cloth or continuous aramid fiber cloth;
  • the fiber cloth in the upper fiber cloth layer is a fiber cloth without surface modification or a fiber cloth with surface modification
  • the fiber cloth in the lower fiber cloth layer is a non-surface-modified fiber cloth or a surface-modified fiber cloth.
  • the number of layers of fiber cloth in the upper fiber cloth layer is one or more layers;
  • the number of fiber cloth layers in the lower fiber cloth layer is one or more layers.
  • the additive is a curing agent and/or an accelerator
  • the dosage of the curing agent is 1% to 50% of the mass of the thermosetting resin
  • the dosage of the accelerator is 0.1%-5% of the mass of the thermosetting resin.
  • the resin-based slurry is poured into the fiber preform by using a vacuum-assisted resin transfer molding process.
  • the curing molding temperature is 25-500° C.
  • the pressure is ⁇ 10 MPa.
  • the present invention also provides a long-short carbon nanotube reinforced and toughened fiber composite material prepared by the preparation method described in the above technical solution.
  • short carbon nanotubes can easily penetrate through narrow fiber gaps and be evenly dispersed in the composite material; while long carbon nanotubes are in the form of fiber yarns It is laid on the surface of the fiber cloth before the resin-based slurry is poured. In this way, the problem of difficult dispersion of long carbon nanotubes has been effectively solved, and the "fiber filtering effect" that often occurs in the VARTM process of carbon nanotubes has been effectively alleviated.
  • the spatial layout of long and short carbon nanotubes in the composite material is optimized. Short carbon nanotubes effectively pass through the narrow gaps between fibers and are evenly distributed throughout the fiber composite sheet. Long carbon nanotubes are enriched in the composite sheet.
  • the interlaminar region enables its excellent mechanical properties to be fully utilized, and simultaneously realizes the dual purpose of intralaminar reinforcement and interlaminar toughening of fiber composites.
  • the present invention not only effectively avoids the "fiber filter effect" that carbon nanotubes generally have in the VARTM process, but makes the short carbon nanotubes uniformly dispersed in the fiber composite material, and at the same time effectively fills the gaps or resin between layers of the fiber composite material In the enriched area, the connection between the layers of the composite material is strengthened by the long carbon nanotubes, which effectively improves the interfacial bonding force between the layers, so that the prepared composite material has excellent mechanical properties such as strength and toughness and physical properties such as thermal and electrical properties.
  • the test results show that the composite material prepared by the invention has a flexural strength of more than 600MPa, which is 6% higher than that of the reference sample, and a type I interlaminar fracture toughness of more than 1500J/m2, which is more than 150% higher than the reference sample.
  • Fig. 1 is the schematic diagram of the cross section of carbon fiber epoxy resin composite material
  • Fig. 2 is the schematic flow sheet of the first method for preparing long carbon nanotube fiber yarn
  • Fig. 3 is the schematic flow sheet of the second method for preparing long carbon nanotube fiber yarn
  • Fig. 4 is a schematic diagram of using a vacuum-assisted resin transfer molding process to pour a resin-based slurry into a fiber preform;
  • Fig. 5 is the schematic diagram of laying structure of fiber prefabricated body in embodiment 1;
  • Fig. 6 is the SEM picture of the cured sample of the resin-based slurry obtained in step S3 in embodiment 1;
  • Fig. 7 is the schematic diagram of the preparation process of embodiment 1;
  • Fig. 8 is the typical load-displacement curve figure of embodiment 1 and comparative example 1 sample
  • Fig. 9 is the load-opening displacement curve figure of embodiment 1 and comparative example 1 sample
  • Fig. 10 is the R curve (the curve of crack growth resistance with crack growth) figure of embodiment 1 and comparative example 1 sample;
  • Fig. 11 is an SEM image of the interlayer structure of the fractured sample in Example 1.
  • the invention provides a method for preparing a long-short carbon nanotube reinforced and toughened fiber composite material, comprising the following steps:
  • the fiber preform includes successively laminated and contacted: an upper fiber cloth layer, a long carbon nanotube fiber yarn layer, and a lower fiber cloth layer;
  • the long carbon nanotube fiber yarn layer is a yarn-like structure formed by long carbon nanotubes
  • the length of the short carbon nanotubes is 0.5-3 ⁇ m, and the average length is ⁇ 2 ⁇ m;
  • the length of the long carbon nanotubes is 50-1000 ⁇ m.
  • the short carbon nanotubes, thermosetting resin and additives are mixed to obtain a resin-based paste.
  • the raw materials for forming the resin-based slurry include: short carbon nanotubes.
  • the length distribution of the short carbon nanotubes is 0.5-3 ⁇ m, and the average length is ⁇ 2 ⁇ m.
  • the diameter of the short carbon nanofiber tube is preferably 1-50 nm.
  • the short carbon nanotubes are obtained by truncating carbon nanotubes.
  • the source of the carbon nanotubes is not particularly limited, and it can be commercially available or prepared according to conventional preparation methods in the art. The truncation methods include: mechanical ball milling or chemical wet etching.
  • the chemical wet etching preferably includes: placing carbon nanotubes in an etching solution for ultrasonic treatment, thereby obtaining truncated carbon nanotubes with a controllable length; specifically, the carbon nanotubes can be regulated by controlling the conditions of ultrasonic treatment. length.
  • carbon nanotubes are placed in aqua regia and ultrasonically treated at 70°C to obtain short carbon nanotubes with a length distribution of 0.5-3 ⁇ m and an average length of ⁇ 2 ⁇ m.
  • the purity of the short carbon nanotubes is preferably 95% or more.
  • the short carbon nanotubes are non-surface-modified short carbon nanotubes or surface-modified short carbon nanotubes.
  • the surface-modified short carbon nanotubes are short carbon nanotubes grafted with functional groups on the surface, that is, the surface has been modified with functional groups.
  • the surface-modifying functional group is selected from one or more of amino, carboxyl and carbonyl.
  • the surface modification can be obtained by performing surface treatment (such as dipping, etc.) with a surface modification agent containing a corresponding surface modification functional group.
  • a surface modification agent containing a corresponding surface modification functional group for example, for the carboxyl group, it can be obtained in the following way: placing the carbon nanotubes in aqua regia for ultrasonic treatment, while truncating the carbon nanotubes to obtain short carbon nanotubes, the surface of the carbon nanotubes is oxidized, thereby grafting on the carboxyl groups to obtain carbon nanotubes with carboxyl groups.
  • Aminated carbon nanotubes can be obtained in the following manner: carbon nanotubes with carboxyl groups are placed in ethylenediamine and a coupling agent for ultrasonic dispersion, thereby obtaining carbon nanotubes grafted with amino groups.
  • the coupling agent is preferably O-(7-azabenzotriazol-1-yl)-N,N,N',N'-tetramethyluronium hexafluorophosphate (ie HATU).
  • the mass ratio of the ethylenediamine to the coupling agent is preferably 1:(1-5).
  • Carbonylated carbon nanotubes can be obtained in the following manner: carbon nanotubes are placed in potassium hydroxide solution for ultrasonic dispersion, thereby obtaining carbon nanotubes grafted with carbonyl groups. In the above surface modification process, washing and drying are preferably performed after ultrasonic treatment, so as to obtain carbon nanotubes grafted with functional groups on the surface.
  • the raw materials for forming the resin-based slurry include: a thermosetting resin.
  • the thermosetting resin preferably includes one or more of epoxy resin, polyester resin, phenolic resin, vinyl resin and bismaleimide resin.
  • the epoxy resin is preferably bisphenol A epoxy resin.
  • the epoxy resin is bisphenol A epoxy resin Epon862.
  • the collocation of resin and surface-modified short carbon nanotubes is preferably as follows: the resin is bisphenol A epoxy resin, and the short carbon nanotubes are amino-modified short carbon nanotubes; the two form a covalent bond in the curing reaction , to achieve a cross-linked structure, which can greatly improve the mechanical properties of the matrix.
  • the raw materials for forming the resin-based slurry include: additives.
  • the additive is a curing agent and/or an accelerator.
  • the curing agent is preferably an amine curing agent, including but not limited to one or more of D230 and dicyandiamide.
  • the accelerator is preferably an amine accelerator, including but not limited to one or more of DMP-30 and triethylamine.
  • short carbon nanotubes, thermosetting resin and additives are mixed to obtain resin-based paste.
  • the dosage ratio of the above three raw materials is preferably as follows: the quality of the short carbon nanotubes is 0.1% to 5% of the mass of the thermosetting resin, specifically 0.1%, 0.5%, 1.0%, 1.5% , 2.0%, 2.5%, 3.0%, 3.5%, 4.0%, 4.5%, 5.0%.
  • the mass of the additive is 0.1% to 50% of the mass of the thermosetting resin, wherein the amount of curing agent is 1% to 50% of the mass of the thermosetting resin, specifically 1%, 5%, 10%, or 15%.
  • the amount of accelerator is 0.1% to 5% of the mass of the thermosetting resin, specifically 0.1%, 0.5%, 1.0%, 1.5%, 2.0%, 2.5%, 3.0%, 3.5%, 4.0%, 4.5%, 5.0%.
  • the order of mixing preferably specifically includes: firstly dispersing the short carbon nanotubes in the thermosetting resin, and then mixing with the additives.
  • the method of dispersing the short carbon nanotubes in the thermosetting resin includes but not limited to ultrasonic, ball milling, milling, mechanical stirring or microfluidic control and the like.
  • the short carbon nanotubes when mixing the short carbon nanotubes and the thermosetting resin: (1) If the viscosity of the thermosetting resin is low (viscosity ⁇ 1000cps), the short carbon nanotubes are directly dispersed in the thermosetting resin. (2) If the viscosity of the thermosetting resin is relatively high (viscosity>1000cps), the short carbon nanotubes are first dispersed in an organic solvent, then mixed with the thermosetting resin, and then the organic solvent is removed.
  • the organic solvent is preferably alcohol or acetone. The method of removing the organic solvent is preferably heating and stirring to remove.
  • the mixing method when mixing with the additives, is not particularly limited, and the materials can be uniformly mixed in a conventional mixing method in the field. After said mixing, degassing is preferably also carried out. After the above treatment, the resin-based slurry is obtained.
  • the resin-based slurry is poured into the fiber preform and solidified to obtain a long-short carbon nanotube reinforced and toughened fiber composite material.
  • a fiber preform is used as the matrix.
  • the fiber preform includes successively laminated and contacted: an upper fiber cloth layer, a long carbon nanotube fiber yarn layer, and a lower fiber cloth layer. That is to say, the fiber prefabricated body is a sandwich structure, with fiber cloth layers on both sides, and a long carbon nanotube fiber yarn layer sandwiched in the middle; the "upper part” and “lower part” have no special orientation restrictions, but are only used to indicate that they are located in the long On both sides of the carbon nanotube fiber yarn layer, if the fiber cloth layer on any one side is the upper fiber cloth layer, then the fiber cloth layer on the other side is naturally the lower fiber cloth layer.
  • the fiber cloth in the upper fiber cloth layer is unidirectional fiber cloth or multi-directional fiber cloth.
  • the fiber cloth in the upper fiber cloth layer is preferably continuous carbon fiber cloth, continuous glass fiber cloth or continuous aramid fiber cloth.
  • the fiber cloth in the upper fiber cloth layer is a non-surface-modified fiber cloth or a surface-modified fiber cloth.
  • the fiber cloth in the lower fiber cloth layer is unidirectional fiber cloth or multi-directional fiber cloth.
  • the fiber cloth in the lower fiber cloth layer is preferably continuous carbon fiber cloth, continuous glass fiber cloth or continuous aramid fiber cloth.
  • the fiber cloth in the lower fiber cloth layer is a non-surface-modified fiber cloth or a surface-modified fiber cloth.
  • the number of fiber cloth layers in the upper fiber cloth layer is one or more layers; the number of fiber cloth layers in the lower fiber cloth layer is one or more layers.
  • the "multi-layer" includes two or more than two layers.
  • the number of fiber cloth layers in the upper fiber cloth layer is the same as the number of fiber cloth layers in the lower fiber cloth layer.
  • the types of fiber cloth of each layer are the same.
  • the types of fiber cloth of each layer are the same.
  • the upper fiber cloth layer is the same as the lower fiber cloth layer, specifically, with the long carbon nanotube fiber yarn layer as the center, the fiber cloths at corresponding positions on both sides are the same.
  • the upper fiber cloth layer is 6 layers of carbon fiber cloth
  • the lower fiber cloth layer is 6 layers of carbon fiber cloth.
  • the fiber yarn of the long carbon nanotube fiber yarn layer located in the central interlayer of the fiber preform is a yarn-like structure formed of long carbon nanotubes, that is, a tulle (or tulle net) formed of long carbon nanotubes.
  • the length distribution of the long carbon nanotubes is 50-1000 ⁇ m; preferably, the average length of the long carbon nanotubes is >100 ⁇ m.
  • the diameter of the long carbon nanofiber tube is preferably 1-50 nm.
  • the long carbon nanotubes are non-surface-modified long carbon nanotubes or surface-modified long carbon nanotubes.
  • the surface-modified long carbon nanotubes are long carbon nanotubes grafted with functional groups on the surface, that is, the surface has been modified with functional groups.
  • the surface-modifying functional group is selected from one or more of amino, carboxyl and carbonyl.
  • the number of layers of the long carbon nanotube fiber yarn is 1 or more layers.
  • the thickness of the long carbon nanotube fiber yarn layer can be adjusted by controlling the deposition time of the single-layer long carbon nanotube fiber yarn or the number of laying layers of the long carbon nanotube fiber yarn.
  • the total thickness of the long carbon nanotube fiber yarn layer is preferably 1 ⁇ m.
  • the long carbon nanotube fiber yarn can be prepared in the following two ways: (1) by floating catalytic chemical vapor deposition (FCCVD).
  • FCCVD floating catalytic chemical vapor deposition
  • the specific process flow is shown in Figure 2.
  • the carbon source is cracked in the high-temperature reaction furnace, and carbon nanotubes are grown on the surface of the catalyst.
  • a large number of carbon nanotubes aggregate and entangle with each other to form carbon nanotube aerogels.
  • the other end of the carbon nanotube airgel can be continuously pulled out and deposited on the surface of the fiber cloth substrate in situ to form a fluffy yarn-like structure, that is, a long carbon nanotube fiber yarn.
  • the process flow is shown in Figure 3.
  • a carbon nanotube array with a certain length is vertically elongated on a silicon substrate by chemical vapor deposition (CVD), and then attached to the fiber in the form of tulle by continuous spinning. Cloth base surface.
  • CVD chemical vapor deposition
  • acid treatment is preferably carried out to remove impurities such as metal catalysts to improve the purity of the carbon nanotubes.
  • the present invention preferably controls the purity of the carbon nanotubes It is more than 95%, which is beneficial to improve the strengthening and toughening effect of the material.
  • the upper fiber cloth layer or the fiber cloth in the lower fiber cloth layer can be directly used as the base, and after the long carbon nanotube fiber yarn layer is deposited on the base, other fiber cloth layers are superimposed to form a prefabricated fiber. body.
  • the mass of the long carbon nanotubes is preferably 0.1% to 5% of the mass of the thermosetting resin in step a), specifically 0.1%, 0.5%, 1.0%, 1.5%, 2.0%, 2.5%, 3.0% %, 3.5%, 4.0%, 4.5%, 5.0%; the long carbon nanotube constitutes the long carbon nanotube fiber yarn layer, therefore, the quality of the long carbon nanotube also represents the quality of the long carbon nanotube fiber yarn layer .
  • the mass percentage of the total mass of the upper fiber cloth and the lower fiber cloth in the composite material is preferably 40% to 80%, specifically, it is equivalent to the total mass of the upper fiber cloth and the lower fiber cloth: step a)
  • the mass ratio of the obtained resin-based slurry is (0.67-4):1, specifically 0.67:1, 0.70:1, 1:1, 2:1, 3:1, 4:1. Controlling the above dosage ratio can not only make the preparation smoothly, but also improve the strengthening and toughening effect of the composite material. If the content of the fiber cloth is too low, it will not be able to effectively strengthen and toughen. If the content of the fiber cloth is too high, it will be difficult to carry out the preparation smoothly. and obtaining a homogeneous composite also affects the material properties.
  • the resin-based slurry obtained in step a) is poured into the fiber preform for curing and molding.
  • the methods adopted include but not limited to vacuum assisted resin transfer molding (VARTM), RTM molding, or hand lay-up molding; the present invention preferably adopts the method of vacuum assisted resin transfer molding (VARTM).
  • VARTM vacuum assisted resin transfer molding
  • the operation of pouring the resin-based slurry into the fiber preform by vacuum-assisted resin transfer molding (VARTM) is shown in Figure 4.
  • the resin-based slurry is uniformly introduced into the fiber preform through the negative pressure of the vacuum pump. At this time , due to factors such as pressure difference and viscosity, there will be resin enrichment at the inlet end, which will easily lead to uneven thickness of the composite material plate.
  • One method that can effectively alleviate this situation is: after the front end of the resin-based slurry flow reaches the outlet, first close the resin inlet, and then close the outlet after the excess resin is sucked out.
  • a double-layer guide net is used to promote the two-way diffusion of the resin on the in-plane and out-of-plane of the fiber preform, and the guide net and the fiber cloth are separated by a peel-off cover to facilitate demoulding. Finally, seal it in a vacuum bag and set aside.
  • the temperature of the curing molding is preferably 25 to 500°C, and the pressure is preferably ⁇ 10MPa; different resins and curing agents can be adjusted within the above conditions; for example, for Epon862 epoxy resin and D-230 curing agent system, the curing conditions are: firstly cured at 80°C for 2 hours, and then cured at 120°C for 2 hours.
  • VARTM Vacuum Assisted Resin Transfer Molding
  • the present invention also provides a long-short carbon nanotube reinforced and toughened fiber composite product produced by the preparation method described in the above technical solution.
  • short carbon nanotubes can easily penetrate through narrow fiber gaps and be evenly dispersed in the composite material; while long carbon nanotubes are in the form of fiber yarns It is laid on the surface of the fiber cloth before the resin-based slurry is poured. In this way, the problem of difficult dispersion of long carbon nanotubes has been effectively solved, and the "fiber filtering effect" that often occurs in the VARTM process of carbon nanotubes has been effectively alleviated.
  • the spatial layout of long and short carbon nanotubes in the composite material is optimized. Short carbon nanotubes effectively pass through the narrow gaps between fibers and are evenly distributed throughout the fiber composite sheet. Long carbon nanotubes are enriched in the composite sheet.
  • the interlaminar region enables its excellent mechanical properties to be fully utilized, and simultaneously realizes the dual purpose of intralaminar reinforcement and interlaminar toughening of fiber composites.
  • the present invention not only effectively avoids the "fiber filter effect" that carbon nanotubes generally have in the VARTM process, but makes the short carbon nanotubes uniformly dispersed in the fiber composite material, and at the same time effectively fills the gaps or resin between layers of the fiber composite material In the enriched area, the connection between the layers of the composite material is strengthened by the long carbon nanotubes, which effectively improves the interfacial bonding force between the layers, so that the prepared composite material has excellent mechanical properties such as strength and toughness and physical properties such as thermal and electrical properties.
  • test results show that the composite material prepared by the present invention
  • the test result shows that the composite material prepared by the present invention has a flexural strength of more than 600MPa, which is 6% higher than that of the reference sample
  • the I-type interlaminar fracture toughness reaches more than 1500J/m 2 , which is more than 150% higher than the benchmark sample.
  • a PTFE film (thickness 25 ⁇ m) is covered on the long carbon nanotube fiber yarn layer, and the end of the middle layer is inserted to cover an area about 60 mm wide to form A pre-crack of a certain length (in order to prepare double cantilever beam specimens). Then, take 6 layers of cut cloth and laminate them on the top of the sample as the upper fiber cloth layer. So far, a fiber preform of 6 layers of carbon fiber unidirectional fabric + long carbon nanotube fiber yarn layer + 6 layers of carbon fiber unidirectional fabric is obtained, the structure of which is shown in FIG. 5 .
  • the PTFE film is laid only to prepare the double cantilever beam sample for subsequent performance testing.
  • the PTFE film is not laid, that is, the actual composite product does not contain PTFE film.
  • step S1 2.4g of the aminated short carbon nanotubes obtained in step S1 are uniformly dispersed in acetone, and then poured into a beaker containing 355g of bisphenol A epoxy resin Epon862, at 1000r/min, water bath temperature 60 Stir mechanically at °C for 6 hours; after the acetone is completely volatilized, add 125g of curing agent D-230, at room temperature, mechanically stir at 500r/min for 10min, and finally degas in a vacuum oven at 25°C for 10min to obtain 482.4g of resin base slurry.
  • Epon862 bisphenol A epoxy resin Epon862
  • the cured sample of the obtained resin-based slurry was brittle at low temperature after being cured, and then observed by SEM. The result is shown in FIG. 6 , and it can be seen that the short carbon nanotubes are uniformly dispersed in the resin.
  • the built VARTM platform is shown in Figure 4.
  • a double-layer guide net is used for the fiber preform, and the guide net and the fiber preform are separated by a glass cover cloth.
  • the base slurry is evenly introduced into the fiber preform.
  • resin enrichment will occur at the inlet end, which will easily lead to uneven thickness of the composite material board.
  • the resin inlet is closed first, and the outlet is closed after the excess resin is sucked out.
  • the VARTM platform After the resin-based slurry is completely poured into the fiber preform, move the VARTM platform as a whole into an oven, firstly cure at 80°C for 2 hours, and then cure at 120°C for 2 hours. Afterwards, it is cooled and demolded to obtain a composite material board.
  • FIG. 7 is a schematic diagram of the preparation process of Example 1.
  • Figure 8 is a typical load-displacement curve of the samples of Example 1 and Comparative Example 1. It can be calculated that the flexural strength of the sample in Example 1 is 624 MPa, and that of the sample in Comparative Example 1 is 589 MPa.
  • Figure 9 is the load-opening displacement curves of Example 1 and Comparative Example 1 samples
  • Figure 10 is the R curve of Example 1 and Comparative Example 1 samples (crack growth resistance increases with crack growth). curve) graph.
  • the mode I interlaminar fracture toughness of the composite material plate of Example 1 is increased from 607J/m 2 to 1536J/m 2 , an increase of more than 150%, thus proving that the present invention proposes Efficiency of long/short carbon nanotube synergistic toughening mechanism.
  • Figure 11 is the SEM image of the interlayer structure of the fracture sample of Example 1, it can be seen that the long carbon nanotubes are enriched in the interlayer region of the composite material.

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Abstract

一种长-短碳纳米管增强增韧纤维复合材料及其制备方法，所述制备方法包括：a)将短碳纳米管、热固性树脂和添加剂混合，得到树脂基浆料；b)将所述树脂基浆料灌注到纤维预制体中并固化成型，得到长-短碳纳米管增强增韧纤维复合材料；其中：所述纤维预制体包括依次层叠接触的：上部纤维布层，长碳纳米管纤维纱层，下部纤维布层；所述长碳纳米管纤维纱层为长碳纳米管形成的纱状结构；所述短碳纳米管的长度为0.5～3μm，平均长度≤2μm；所述长碳纳米管的长度为50～1000μm。该方法优化了长和短的碳纳米管在复合材料内的空间布局，同步实现纤维复合材料的层内增强和层间增韧的双重目的。

Description

一种长-短碳纳米管增强增韧纤维复合材料及其制备方法
本申请要求于2022年02月17日提交中国专利局、申请号为202210146054.3、发明名称为“一种长-短碳纳米管增强增韧纤维复合材料及其制备方法”的中国专利申请的优先权，其全部内容通过引用结合在本申请中。
技术领域
本发明涉及复合材料领域，特别涉及一种长-短碳纳米管增强增韧纤维复合材料及其制备方法。
背景技术
过去的半个世纪见证了树脂基复合材料的迅速发展。它们具有更高的比刚度、强度和优异的疲劳性能以及抗腐蚀性，使它们成为在飞机、汽车、民用、船舶和海上平台设施等。当前国际复合材料市场巨大，基于复合材料的多项终端产品已大量投放市场。通过纳米增强复合材料的性能，降低基体重量，替代在复合材料中昂贵的碳纤维和合成纤维，为在如航空航天、汽车、能源等领域提供了持续竞争的优势。高性能纳米增强复合材料的开发已成为该领域一个极为重要的应用方向。碳纳米管是迄今为止地球上所发现的强度最高的材料之一，其拉伸强度高强钢的20倍，其杨氏模量比碳纤维高一个数量级，大约为钢的100倍，其超强力学性能、优异的电学、化学和热稳定性,使其在研究开发超强复合材料领域发挥多方面的作用。但是，目前仍存在许多技术瓶颈，如大长径比及高比表面积使得CNT难以均匀分散于树脂基体中，并且少量的CNT会显著地提高树脂的黏度，造成树脂导入和纤维预成型体浸润困难。
就碳纳米管增强连续型纤维复合材料而言，如何使得碳纳米管成功穿过狭窄的连续型纤维之间的间隙，均匀分散在复合材料中，是一个亟待解决的难题。碳纤维的直径一般为5-10微米，而复合材料中碳纤维的含量达55％或以上，性能更佳，更好的发挥碳纤维的作用。图1为碳纤维环氧树脂复合材料横截面的示意图，假设碳纤维的直径为7微米(如日本东丽产T700碳纤维)，它在复合材料中的体积分数为55％；同时假设碳纤维均匀地分布于环氧树脂基体中，则相邻碳纤维之间的距离不到2微米。由于商业化碳纳米管的长度通常在 20-100微米之间，这样一来，碳纳米管根本不能通过碳纤维的间隙，引起“纤维过滤效应”。如果不解决这个问题，纤维复合材料力学性能的也难以显著提升。
另外，纤维复合材料通常以层压板制品形式使用，受到其层级结构特性和树脂基体本征脆性的影响，其沿厚度方向的承载能力较低，在面内压缩、弯曲、疲劳和横向冲击等荷载作用下，容易发生分层损伤。一旦分层开始并在层压板内部传播，整个结构的刚度将逐渐降低，最终导致灾难性的失效。因此，提高其层间断裂韧性在许多工程应用中至关重要。
发明内容
有鉴于此，本发明的目的在于提供一种长-短碳纳米管增强增韧纤维复合材料及其制备方法。本发明提供的长-短碳纳米管增强增韧纤维复合材料能够同时实现复合材料的基体增强和层间增韧。
本发明提供了一种长-短碳纳米管增强增韧纤维复合材料的制备方法，包括以下步骤：
a)将短碳纳米管、热固性树脂和添加剂混合，得到树脂基浆料；
b)将所述树脂基浆料灌注到纤维预制体中并固化成型，得到长-短碳纳米管增强增韧纤维复合材料；
其中：
所述纤维预制体包括依次层叠接触的：上部纤维布层，长碳纳米管纤维纱层，下部纤维布层；
所述长碳纳米管纤维纱层为长碳纳米管形成的纱状结构；
所述短碳纳米管的长度为0.5～3μm，平均长度≤2μm；
所述长碳纳米管的长度为50～1000μm。
优选的，所述短碳纳米管为未经表面修饰的短碳纳米管或为表面修饰的短碳纳米管；
所述长碳纳米管为未经表面修饰的长碳纳米管或为表面修饰的长碳纳米管；
所述表面修饰的短碳纳米管中，表面修饰官能团选自氨基、羧基和羰基中 的一种或几种；
所述表面修饰的长碳纳米管中，表面修饰官能团选自氨基、羧基和羰基中的一种或几种。
优选的，所述热固性树脂包括环氧树脂、聚酯树脂、酚醛树脂、乙烯基树脂和双马来酰亚胺树脂中的一种或几种。
优选的，所述短碳纳米管的质量为所述热固性树脂质量的0.1％～5％；
所述长碳纳米管的质量为所述热固性树脂质量的0.1％～5％；
所述上部纤维布与下部纤维布的总质量在所述复合材料中的质量百分比为40％～80％。
优选的，所述上部纤维布层中的纤维布为单向纤维织布或多向纤维织布；
所述下部纤维布层中的纤维布为单向纤维织布或多向纤维织布；
所述上部纤维布层中的纤维布为连续型碳纤维布、连续型玻璃纤维布或连续型芳纶纤维布；
所述下部纤维布层中的纤维布为连续型碳纤维布、连续型玻璃纤维布或连续型芳纶纤维布；
所述上部纤维布层中的纤维布为未经表面修饰的纤维布或为表面修饰的纤维布；
所述下部纤维布层中的纤维布为未经表面修饰的纤维布或为表面修饰的纤维布。
优选的，所述上部纤维布层中的纤维布的层数为一层或多层；
所述下部纤维布层中的纤维布层数为一层或多层。
优选的，所述添加剂为固化剂和/或促进剂；
所述固化剂用量为所述热固性树脂质量的1％～50％；
所述促进剂用量为所述热固性树脂质量的0.1％～5％。
优选的，所述步骤b)中，利用真空辅助树脂传递模塑工艺将所述树脂基浆料灌注到纤维预制体中。
优选的，所述步骤b)中，所述固化成型的温度为25～500℃，压力为≤10MPa。
本发明还提供了一种上述技术方案中所述的制备方法制得的长-短碳纳米 管增强增韧纤维复合材料。
本发明提供的制备方法，在树脂和纤维相互浸润的过程中，短碳纳米管可以轻易渗透过狭窄的纤维间隙，均匀地分散在复合材料当中；而长的碳纳米管则以纤维纱的形式在树脂基浆料灌注之前被陈铺于纤维布的表面。这样一来，长碳纳米管的难分散问题得到了有效的解决，而碳纳米管在VARTM工艺中常出现的“纤维过滤效应”有得到了有效的缓解。优化了长和短的碳纳米管在复合材料内的空间布局，短碳纳米管有效通过纤维之间狭窄的间隙，均匀分布于整个纤维复合材料板中，长碳纳米管富集于复合材料板的层间区域，使得其优异的力学性能得以充分发挥，同步实现纤维复合材料的层内增强和层间增韧的双重目的。总之，本发明既有效地避免了碳纳米管在VARTM工艺中普遍存在的“纤维过滤效应”，使得短碳纳米管均匀分散在纤维复合材料中，同时有效填补纤维复合材料层间的空隙或树脂富集区域，通过长碳纳米管加强复合材料层间的连接，有效提高层间的界面结合力，使得所制备的复合材料具备出色的力学性能如强度和韧性以及物理性能如热学和电学性能。
试验结果表明，本发明制备的复合材料，弯曲强度达到600MPa以上，相比于基准样提升了6％，I型层间断裂韧性达到1500J/m 2以上，相比于基准样提升超过150％。
附图说明
图1为碳纤维环氧树脂复合材料横截面的示意图；
图2为制备长碳纳米管纤维纱的第一种方法的流程示意图；
图3为制备长碳纳米管纤维纱的第二种方法的流程示意图；
图4为利用真空辅助树脂传递模塑工艺将树脂基浆料灌注纤维预制体的示意图；
图5为实施例1中纤维预制体的铺设结构示意图；
图6为实施例1中步骤S3所得树脂基浆料的固化样的SEM图；
图7为实施例1的制备过程示意图；
图8为实施例1和对比例1样品典型的荷载-位移曲线图；
图9为实施例1和对比例1样品的荷载-开口位移曲线图；
图10为实施例1和对比例1样品的R曲线(裂纹扩展阻力随裂纹扩展的曲线)图；
图11为实施例1断裂样品层间结构SEM图。
具体实施方式
本发明提供了一种长-短碳纳米管增强增韧纤维复合材料的制备方法，包括以下步骤：
a)将短碳纳米管、热固性树脂和添加剂混合，得到树脂基浆料；
b)将所述树脂基浆料灌注到纤维预制体中并固化成型，得到长-短碳纳米管增强增韧纤维复合材料；
其中：
所述纤维预制体包括依次层叠接触的：上部纤维布层，长碳纳米管纤维纱层，下部纤维布层；
所述长碳纳米管纤维纱层为长碳纳米管形成的纱状结构；
所述短碳纳米管的长度为0.5～3μm，平均长度≤2μm；
所述长碳纳米管的长度为50～1000μm。
【关于步骤a】：
将短碳纳米管、热固性树脂和添加剂混合，得到树脂基浆料。
按照本发明，形成树脂基浆料的原料包括：短碳纳米管。
本发明中，所述短碳纳米管的长度分布为0.5～3μm，平均长度≤2μm。本发明中，所述短碳纳米纤维管的直径优选为1～50nm。本发明中，所述短碳纳米管通过将碳纳米管截短的方式获得。其中，所述碳纳米管的来源没有特殊限制，为市售商业品或按照本领域常规制备方法制得即可。所述截短的方式包括：机械球磨或化学湿法腐蚀。其中，所述化学湿法腐蚀优选包括：将碳纳米管置于腐蚀液中进行超声处理，从而得到长度可控的截短的碳纳米管；具体可通过控制超声处理的条件来调控碳纳米管的长度。在本发明的一些实施例中，将碳纳米管置于王水中，于70℃超声处理，得到长度分布为0.5～3μm，平均长度≤2μm的短碳纳米管。
本发明中，所述短碳纳米管的纯度优选为95％以上。
本发明中，所述短碳纳米管为未经表面修饰的短碳纳米管或为表面修饰的短碳纳米管。其中，所述表面修饰的短碳纳米管为表面嫁接了官能团的短碳纳米管，即进行了表面官能团修饰。本发明中，表面修饰的短碳纳米管中，表面修饰官能团选自氨基、羧基和羰基中的一种或几种。
本发明中，所述表面修饰可通过利用含对应表面修饰官能团的表面修饰剂进行表面处理(如浸渍等)而获得。例如，对于羧基，可通过以下方式获得：将碳纳米管置于王水中进行超声处理，在将碳纳米管截短获得短碳纳米管的同时，碳纳米管的表面被氧化，从而嫁接上了羧基，得到带有羧基的碳纳米管。对于氨基化碳纳米管，可通过以下方式获得：将带有羧基的碳纳米管置于乙二胺和偶联剂中进行超声分散，从而得到嫁接了氨基的碳纳米管。其中：所述偶联剂优选为O-(7-氮杂苯并三唑-1-基)-N,N,N',N'-四甲基脲六氟磷酸酯(即HATU)。所述乙二胺与偶联剂的质量比优选为1∶(1～5)。对于羰基化碳纳米管，可通过以下方式获得：将碳纳米管置于氢氧化钾溶液中进行超声分散，从而得到嫁接了羰基的碳纳米管。以上表面修饰的过程中，在超声处理之后，优选进行洗涤和干燥，从而得到表面嫁接了官能团的碳纳米管。
按照本发明，形成树脂基浆料的原料包括：热固性树脂。
本发明中，所述热固性树脂优选包括环氧树脂、聚酯树脂、酚醛树脂、乙烯基树脂和双马来酰亚胺树脂中的一种或几种。其中，所述环氧树脂优选为双酚A环氧树脂。在本发明的一些实施例中，环氧树脂为双酚A环氧树脂Epon862。
本发明中，根据不同的树脂基体，可选择搭配不同化学修饰的短碳纳米管，采用嫁接了合适官能团的碳纳米管，其和树脂基体进行固化反应时，可形成共价键或非共价键，使纤维复合材料取得理想的性能增强效果。本发明中，树脂与表面修饰短碳纳米管的搭配优选如下：树脂为双酚A环氧树脂，短碳纳米管为经氨基修饰的短碳纳米管；二者在固化反应中形成共价键，达成交联结构，能够大大提高基体的力学性能。
按照本发明，形成树脂基浆料的原料包括：添加剂。
本发明中，所述添加剂为固化剂和/或促进剂。其中，所述固化剂优选为胺类固化剂，包括但不限于D230和双氰胺中的一种或几种。所述促进剂优选 为胺类促进剂，包括但不限于DMP-30和三乙胺中的一种或几种。
按照本发明，将短碳纳米管、热固性树脂和添加剂混合，得到树脂基浆料。
本发明中，以上三种原料的用量比优选为如下：所述短碳纳米管的质量为所述热固性树脂质量的0.1％～5％，具体可为0.1％、0.5％、1.0％、1.5％、2.0％、2.5％、3.0％、3.5％、4.0％、4.5％、5.0％。所述添加剂的质量为所述热固性树脂质量的0.1％～50％，其中，固化剂用量为所述热固性树脂质量的1％～50％，具体可为1％、5％、10％、15％、20％、25％、30％、35％、40％、45％、50％；促进剂用量为所述热固性树脂质量的0.1％～5％，具体可为0.1％、0.5％、1.0％、1.5％、2.0％、2.5％、3.0％、3.5％、4.0％、4.5％、5.0％。
本发明中，所述混合的顺序优选具体包括：先将短碳纳米管分散于热固性树脂中，再与添加剂混合。
本发明中，短碳纳米管分散于热固性树脂中的方式包括但不限于超声、球磨、碾磨、机械搅拌或微流控等。其中，在将短碳纳米管和热固性树脂混合时：(1)若热固性树脂粘度较低(粘度≤1000cps)，则直接将短碳纳米管分散于热固性树脂中。(2)若热固性树脂粘度较高(粘度＞1000cps)，则先将短碳纳米管分散于有机溶剂中，再与热固性树脂混合，之后再除去有机溶剂。其中，所述有机溶剂优选为酒精或丙酮。所述除去有机溶剂的方式优选为加热搅拌除去。
本发明中，在与添加剂混合时，混合方式没有特殊限制，为本领域常规混料方式将物料混匀即可。在所述混合后，优选还进行除气。经上述处理后，得到树脂基浆料。
【关于步骤b】：
将所述树脂基浆料灌注到纤维预制体中并固化成型，得到长-短碳纳米管增强增韧纤维复合材料。
按照本发明，采用纤维预制体作为基体。
本发明中，所述纤维预制体包括依次层叠接触的：上部纤维布层，长碳纳米管纤维纱层，下部纤维布层。即所述纤维预制体为夹心结构，两侧均为纤维布层，中间夹有长碳纳米管纤维纱层；其中，“上部”、“下部”没有特殊的方 位限制，只是用于表示位于长碳纳米管纤维纱层的两侧，其中任意一侧的纤维布层为上部纤维布层，则另一侧的纤维布层自然为下部纤维布层。
本发明中，所述上部纤维布层中的纤维布为单向纤维织布或多向纤维织布。本发明中，所述上部纤维布层中的纤维布优选为连续型碳纤维布、连续型玻璃纤维布或连续型芳纶纤维布。本发明中，所述上部纤维布层中的纤维布为未经表面修饰的纤维布或为表面修饰的纤维布。
本发明中，所述下部纤维布层中的纤维布为单向纤维织布或多向纤维织布。本发明中，所述下部纤维布层中的纤维布优选为连续型碳纤维布、连续型玻璃纤维布或连续型芳纶纤维布。本发明中，所述下部纤维布层中的纤维布为未经表面修饰的纤维布或为表面修饰的纤维布。
本发明中，所述上部纤维布层中的纤维布的层数为一层或多层；所述下部纤维布层中的纤维布层数为一层或多层。其中，所述“多层”包括两层或多于两层。本发明中，优选的，所述上部纤维布层中的纤维布的层数与下部纤维布层中的纤维布的层数相同。本发明中，优选的，所述上部纤维布层中，各层纤维布的种类相同。本发明中，优选的，所述下部纤维布层中，各层纤维布的种类相同。本发明中，优选的，上部纤维布层与下部纤维布层相同，具体的，以长碳纳米管纤维纱层为中心，两侧对应位置的纤维布相同。在本发明的一些实施例中，上部纤维布层为6层碳纤维布，下部纤维布层为6层碳纤维布。
本发明中，位于纤维预制体中心夹层的长碳纳米管纤维纱层的纤维纱为长碳纳米管形成的纱状结构，即由长碳纳米管形成的薄纱(或称薄纱网)。其中，所述长碳纳米管的长度分布为50～1000μm；优选的，所述长碳纳米管的平均长度>100μm。本发明中，所述长碳纳米纤维管的直径优选为1～50nm。本发明中，所述长碳纳米管为未经表面修饰的长碳纳米管或为表面修饰的长碳纳米管。其中，所述表面修饰的长碳纳米管为表面嫁接了官能团的长碳纳米管，即进行了表面官能团修饰。本发明中，表面修饰的长碳纳米管中，表面修饰官能团选自氨基、羧基和羰基中的一种或几种。表面修饰的方式以及表面修饰碳纳米管与树脂基体的搭配与前文短碳纳米管的情况一致，在此不再赘述。
本发明中，所述长碳纳米管纤维纱层中，长碳纳米管纤维纱的层数为1层或多层。本发明中，所述长碳纳米管纤维纱层厚度可通过控制单层长碳纳米管 纤维纱的沉积时间或长碳纳米管纤维纱的铺设层数来调节。本发明中，所述长碳纳米管纤维纱层的总厚度优选为1μm。
本发明中，所述长碳纳米管纤维纱可通过以下两种方式制得：(1)通过浮动催化化学气相沉积法(FCCVD)制备。具体工艺流程如图2所示，碳源在高温反应炉中裂解，并在催化剂表面生长出碳纳米管，大量碳纳米管互相聚集、缠结，形成碳纳米管气凝胶，从高温反应炉的另一端可以将碳纳米管气凝胶连续拉出，原位沉积在纤维布基底表面，形成蓬松的纱状结构，即长碳纳米管纤维纱。(2)通过阵列抽丝法制备。工艺流程如图3所示，先通过化学气相沉积法(CVD)在硅衬底上竖向伸长具有一定长度的碳纳米管阵列，然后通过连续抽丝将其以薄纱的形式附着在纤维布基底表面。本发明中，在上述制备过程中，在得到碳纳米管后、制备薄纱之前，优选先进行酸处理去除金属催化剂等杂质，来提高碳纳米管的纯度，本发明优选控制碳纳米管的纯度为95％以上，有利于提升材料的增强增韧效果。
以上制备过程中，可以直接以上部纤维布层或下部纤维布层中的纤维布作为基底，在该基底上沉积形成长碳纳米管纤维纱层后，再叠加其它纤维布层，从而形成纤维预制体。
本发明中，所述长碳纳米管的质量优选为步骤a)中热固性树脂质量的0.1％～5％，具体可为0.1％、0.5％、1.0％、1.5％、2.0％、2.5％、3.0％、3.5％、4.0％、4.5％、5.0％；所述长碳纳米管构成长碳纳米管纤维纱层，因此，所述长碳纳米管的质量也代表长碳纳米管纤维纱层的质量。
本发明中，上部纤维布与下部纤维布的总质量在所述复合材料中的质量百分比优选为40％～80％，具体的，相当于上部纤维布与下部纤维布的总质量∶步骤a)所得树脂基浆料质量的质量比为(0.67～4)∶1，具体可为0.67∶1、0.70∶1、1∶1、2∶1、3∶1、4∶1。控制在上述用量比下，既能够顺利制备，又能够提高复合材料的增强增韧效果，若纤维布的含量过低，则不能有效增强增韧，若纤维布含量过高，则难以顺利实施制备和获得均匀的复合体，也影响材料性能。
本发明中，将步骤a)所得树脂基浆料灌注到纤维预制体中进行固化成型。本发明中，所采用的方式包括但不限于真空辅助树脂传递模塑(VARTM)、RTM 成型、或手糊成型等；本发明优选采用真空辅助树脂传递模塑(VARTM)的方式。采用真空辅助树脂传递模塑(VARTM)将树脂基浆料灌注到纤维预制体中的操作如图4所示，通过真空泵的负压作用将树脂基浆料均匀的引入纤维预制体中，此时，由于压差、黏度等因素，在入口端会出现树脂富集现象，容易导致复合材料板的厚度不匀。可以有效缓解此情况的一种做法是：待树脂基浆料流前端抵达出口后，先关闭树脂入口，等多余树脂吸出后，再关闭出口。过程中使用双层导流网以促进树脂在纤维预制体的面内和面外双向扩散，导流网和纤维布之间用剥离罩布分隔开来，以方便脱模。最后用真空袋密封，备用。
本发明中，经上述灌注操作后，进行固化成型。本发明中，所述固化成型的温度优选为25～500℃，压力优选为≤10MPa；不同的树脂和固化剂，可在上述条件范围内调整；例如，对于Epon862环氧树脂和D-230固化剂体系，固化条件为：先在80℃固化2h，再在120℃固化2h。以真空辅助树脂传递模塑(VARTM)灌注样品为例，在灌注完后，可将整个VARTM平台移入烘箱固化，或在平板硫化机上加压固化。待固化结束后，冷却脱模，即得长-短碳纳米管增强增韧纤维复合材料产品。
本发明还提供了一种上述技术方案中所述的制备方法制得的长-短碳纳米管增强增韧纤维复合材料产品。
本发明提供的制备方法，在树脂和纤维相互浸润的过程中，短碳纳米管可以轻易渗透过狭窄的纤维间隙，均匀地分散在复合材料当中；而长的碳纳米管则以纤维纱的形式在树脂基浆料灌注之前被陈铺于纤维布的表面。这样一来，长碳纳米管的难分散问题得到了有效的解决，而碳纳米管在VARTM工艺中常出现的“纤维过滤效应”有得到了有效的缓解。优化了长和短的碳纳米管在复合材料内的空间布局，短碳纳米管有效通过纤维之间狭窄的间隙，均匀分布于整个纤维复合材料板中，长碳纳米管富集于复合材料板的层间区域，使得其优异的力学性能得以充分发挥，同步实现纤维复合材料的层内增强和层间增韧的双重目的。总之，本发明既有效地避免了碳纳米管在VARTM工艺中普遍存在的“纤维过滤效应”，使得短碳纳米管均匀分散在纤维复合材料中，同时有效填补纤维复合材料层间的空隙或树脂富集区域，通过长碳纳米管加强复合材料层间的连接，有效提高层间的界面结合力，使得所制备的复合材料具备出色的 力学性能如强度和韧性以及物理性能如热学和电学性能。
试验结果表明，本发明制备的复合材料，试验结果表明，本发明制备的复合材料，弯曲强度达到600MPa以上，相比于基准样提升了6％，I型层间断裂韧性达到1500J/m 2以上，相比于基准样提升超过150％。
为了进一步理解本发明，下面结合实施例对本发明优选实施方案进行描述，但是应当理解，这些描述只是为进一步说明本发明的特征和优点，而不是对本发明权利要求的限制。
实施例1
S1、制备氨基化短碳纳米管
将10g碳纳米管倒入含有300mL王水的烧杯中，于70℃、2.5KW超声处理12h，得到长度分布为0.5～3μm、平均长度2μm的短碳纳米管。在上述碳纳米管截短的过程中，碳纳米管的表面被氧化，嫁接上了羧基。将带有羧基的短碳纳米管置于乙二胺和HATU偶联剂的混合液中(乙二胺∶偶联剂的质量比为1∶1～5)，室温下、2.5KW超声分散12h，之后，用无水乙醇和去离子水洗涤数次，烘干，得到近10g表面嫁接了氨基的短碳纳米管。
S2、制备纤维预制体
取碳纤维单向布(东丽T300-3000，密度为1.76g/cm 3)，裁剪成30×30cm的布块，然后按照[0] 6s的叠层方式手工铺设纤维预制体，参见图5。具体的：取6层裁剪好的布块层叠作为下部纤维布层，以此为基底；通过化学气相沉积法(CVD)在硅衬底上竖向伸长具有一定长度的碳纳米管阵列，然后通过连续抽丝将其以薄纱的形式附着在上述纤维布层基底上，形成长碳纳米管纤维纱层(共铺设3层，总厚度为300nm，其中长碳纳米管的长度分布为50～1000μm)。为制备双悬臂梁试样(按ASTM D5528测试标准的要求)，将PTFE薄膜(厚度25μm)覆盖在长碳纳米管纤维纱层上，插入在中间层的端部覆盖约60mm宽的区域以形成一定长度的预裂纹(以便制备双悬臂梁试件)。然后，再取6层裁剪好的布块层叠在上述样品的上部作为上部纤维布层。至此，得到6层碳纤维单向布+长碳纳米管纤维纱层+6层碳纤维单向布的纤维预制体，结构如图5所示。注：上述制备过程中，铺设PTFE薄膜只是为了制备双悬臂梁试样以便进行后续性能测试，实际生产复合材料的过程中，不铺设PTFE薄膜，即实际复合材 料产品是不含PTFE薄膜的。
S3、制备树脂基浆料
利用微流控设备，将2.4g步骤S1所得氨基化的短碳纳米管均匀分散于丙酮中，然后，倒入含有355g双酚A环氧树脂Epon862的烧杯中，在1000r/min、水浴温度60℃的条件下机械搅拌6h；待丙酮完全挥发后，加入125g固化剂D-230，在室温下，于500r/min机械搅拌10min，最后在25℃真空烘箱中除气10min，得到482.4g树脂基浆料。
对所得树脂基浆料的固化后的固化样品低温脆断，然后进行SEM观测，结果如图6所示，可以看出，短碳纳米管在树脂中均匀分散。
S4、制备复合材料
搭建的VARTM平台如图4所示，对纤维预制体使用双层导流网，导流网和纤维预制体之间用玻璃罩布分隔开来，通过真空泵的负压作用将步骤S3所得树脂基浆料均匀引入纤维预制体中，此时，由于压差、黏度等因素，在入口端会出现树脂富集现象，容易导致复合材料板的厚度不匀。为缓解此情况，待树脂基浆料流前端抵达出口后，先关闭树脂入口，等多余树脂吸出后，再关闭出口。待树脂基浆料完全灌注到纤维预制体中后，将VARTM平台整体移入烘箱中，先在80℃固化2h，再在120℃固化2h。之后，冷却脱模，得到复合材料板。
实施例1的上述整个制备流程如图7所示，图7为实施例1的制备过程示意图。
对比例1
制备基准样品(无碳纳米管)：
按照实施例1实施，不同的是，步骤S2制备纤维预制体的过程中，不放置长碳纳米管纤维纱层，且步骤S3制备树脂基浆料的过程中，不添加短碳纳米管。
实施例2：测试
(1)强度测试
参照ASTM D790分别对实施例1和对比例1样品进行三点弯曲强度测试，结果如图8所示，图8为实施例1和对比例1样品典型的荷载-位移曲线图。 计算可得，实施例1样品的弯曲强度为624MPa，对比例1样品的弯曲强度为589MPa。
(2)断裂韧性测试
分别对实施例1和对比例1样品进行断裂性能测试，参照ASTM D5528。结果分别如图9-10所示，图9为实施例1和对比例1样品的荷载-开口位移曲线图，图10为实施例1和对比例1样品的R曲线(裂纹扩展阻力随裂纹扩展的曲线)图。
可以看出，与对比例1基准样相比，实施例1复合材料板的I型层间断裂韧性从607J/m 2提高到1536J/m 2，增幅超过150％，从而证明本发明所提出的长/短碳纳米管协同增韧机制的高效性。
(3)层间结构表征
对第(2)项断裂性能测试后的实施例1断裂样品进行表征，结果如图11所示，图11为实施例1断裂样品层间结构SEM图，可以看出，长碳纳米管富集于复合材料的层间区域。
本文中应用了具体个例对本发明的原理及实施方式进行了阐述，以上实施例的说明只是用于帮助理解本发明的方法及其核心思想，包括最佳方式，并且也使得本领域的任何技术人员都能够实践本发明，包括制造和使用任何装置或系统，和实施任何结合的方法。应当指出，对于本技术领域的普通技术人员来说，在不脱离本发明原理的前提下，还可以对本发明进行若干改进和修饰，这些改进和修饰也落入本发明权利要求的保护范围内。本发明专利保护的范围通过权利要求来限定，并可包括本领域技术人员能够想到的其他实施例。如果这些其他实施例具有近似于权利要求文字表述的结构要素，或者如果它们包括与权利要求的文字表述无实质差异的等同结构要素，那么这些其他实施例也应包含在权利要求的范围内。

Claims (10)

  1. 一种长-短碳纳米管增强增韧纤维复合材料的制备方法，其特征在于，包括以下步骤：
    a)将短碳纳米管、热固性树脂和添加剂混合，得到树脂基浆料；
    b)将所述树脂基浆料灌注到纤维预制体中并固化成型，得到长-短碳纳米管增强增韧纤维复合材料；
    其中：
    所述纤维预制体包括依次层叠接触的：上部纤维布层，长碳纳米管纤维纱层，下部纤维布层；
    所述长碳纳米管纤维纱层为长碳纳米管形成的纱状结构；
    所述短碳纳米管的长度为0.5～3μm，平均长度≤2μm；
    所述长碳纳米管的长度为50～1000μm。
  2. 根据权利要求1所述的制备方法，其特征在于，所述短碳纳米管为未经表面修饰的短碳纳米管或为表面修饰的短碳纳米管；
    所述长碳纳米管为未经表面修饰的长碳纳米管或为表面修饰的长碳纳米管；
    所述表面修饰的短碳纳米管中，表面修饰官能团选自氨基、羧基和羰基中的一种或几种；
    所述表面修饰的长碳纳米管中，表面修饰官能团选自氨基、羧基和羰基中的一种或几种。
  3. 根据权利要求1所述的制备方法，其特征在于，所述热固性树脂包括环氧树脂、聚酯树脂、酚醛树脂、乙烯基树脂和双马来酰亚胺树脂中的一种或几种。
  4. 根据权利要求1所述的制备方法，其特征在于，所述短碳纳米管的质量为所述热固性树脂质量的0.1％～5％；
    所述长碳纳米管的质量为所述热固性树脂质量的0.1％～5％；
    所述上部纤维布与下部纤维布的总质量在所述复合材料中的质量百分比为40％～80％。
  5. 根据权利要求1所述的制备方法，其特征在于，所述上部纤维布层中的纤维布为单向纤维织布或多向纤维织布；
    所述下部纤维布层中的纤维布为单向纤维织布或多向纤维织布；
    所述上部纤维布层中的纤维布为连续型碳纤维布、连续型玻璃纤维布或连续型芳纶纤维布；
    所述下部纤维布层中的纤维布为连续型碳纤维布、连续型玻璃纤维布或连续型芳纶纤维布；
    所述上部纤维布层中的纤维布为未经表面修饰的纤维布或为表面修饰的纤维布；
    所述下部纤维布层中的纤维布为未经表面修饰的纤维布或为表面修饰的纤维布。
  6. 根据权利要求1所述的制备方法，其特征在于，所述上部纤维布层中的纤维布的层数为一层或多层；
    所述下部纤维布层中的纤维布层数为一层或多层。
  7. 根据权利要求1所述的制备方法，其特征在于，所述添加剂为固化剂和/或促进剂；
    所述固化剂用量为所述热固性树脂质量的1％～50％；
    所述促进剂用量为所述热固性树脂质量的0.1％～5％。
  8. 根据权利要求1所述的制备方法，其特征在于，所述步骤b)中，利用真空辅助树脂传递模塑工艺将所述树脂基浆料灌注到纤维预制体中。
  9. 根据权利要求1所述的制备方法，其特征在于，所述步骤b)中，所述固化成型的温度为25～500℃，压力为≤10MPa。
  10. 一种权利要求1～9中任一项所述的制备方法制得的长-短碳纳米管增强增韧纤维复合材料。
PCT/CN2022/086505 2022-02-17 2022-04-13 一种长-短碳纳米管增强增韧纤维复合材料及其制备方法 WO2023155285A1 (zh)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN117964996A (zh) * 2024-01-30 2024-05-03 华中科技大学 基于碳纳米管树脂分散的本体防雷击碳纤维复合材料及其制备方法

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20140343191A1 (en) * 2011-09-30 2014-11-20 Jx Nippon Oil & Energy Corporation Fiber-reinforced resin composite material and method for producing same
CN104327454A (zh) * 2014-10-11 2015-02-04 沈阳航空航天大学 一种碳纳米管/连续纤维混杂增强复合材料的制备方法
CN104558650A (zh) * 2014-12-17 2015-04-29 天津大学 碳纳米管/短切碳纤维/环氧树脂复合材料的制备方法
CN112208161A (zh) * 2020-09-07 2021-01-12 蒙娜丽莎集团股份有限公司 一种层状纤维体增韧树脂基复合材料及其制备方法

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20140343191A1 (en) * 2011-09-30 2014-11-20 Jx Nippon Oil & Energy Corporation Fiber-reinforced resin composite material and method for producing same
CN104327454A (zh) * 2014-10-11 2015-02-04 沈阳航空航天大学 一种碳纳米管/连续纤维混杂增强复合材料的制备方法
CN104558650A (zh) * 2014-12-17 2015-04-29 天津大学 碳纳米管/短切碳纤维/环氧树脂复合材料的制备方法
CN112208161A (zh) * 2020-09-07 2021-01-12 蒙娜丽莎集团股份有限公司 一种层状纤维体增韧树脂基复合材料及其制备方法

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN117964996A (zh) * 2024-01-30 2024-05-03 华中科技大学 基于碳纳米管树脂分散的本体防雷击碳纤维复合材料及其制备方法

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