An aqueous sizing agent for carbon fibers and use thereof

Abstract

The present application provides a kind of sizing agent for aqueous carbon fiber and its application, belong to fiber sizing agent technical field, according to the total mass is 100 parts, sizing agent includes: component 1: sulfonated polyarylether A 0.1-15 parts, component 2: sulfonated polyarylether B 0.1-10 parts, deionized water 75~99.8 parts, wherein the glass transition temperature of component 2 is higher than that of component 1.Sulfonated polyarylether A, sulfonated polyarylether B can be self-emulsified in water to form hydrophilic microparticles, which can be adsorbed on the surface of carbon fiber, and the two microparticles are stacked on the surface of carbon fiber to form a sizing agent layer after sizing.The sizing agent can also contain a small amount of non-ionic emulsifier;Or, mixed with general anionic, non-ionic sizing agent, improve wear resistance, temperature resistance and other properties.The sizing agent provided by the present application has the characteristics of water-soluble, heat-resistant, wear-resistant, good biocompatibility and the like.Using the sizing agent can form a mechanical interlocking structure in the fiber / matrix resin interface layer, thereby effectively improving the performance of fiber reinforced polyarylether composite material.

Description

Technical Field

[0001] This invention belongs to the field of fiber sizing agent technology, specifically, it relates to a water-based carbon fiber sizing agent, its preparation method, and its application in thermoplastic resin-based composite materials. Background Technology

[0002] At present, fiber-reinforced thermoplastic polymer composites have advantages such as being lightweight, high-strength, fatigue-resistant, corrosion-resistant, simple to mold, and recyclable, and have received widespread attention in the fields of aerospace, transportation, wind power and new energy, electronic equipment and sports.

[0003] Sufficient wetting of carbon fibers by the matrix resin is essential for preparing high-performance carbon fiber reinforced polyetheretherketone (PEEK) composites. Incomplete wetting may lead to bubble formation at the interface, resulting in weak interfacial bonding. Traditional epoxy resin sizing agents have poor structural compatibility with polyetheretherketone (PEEK) resins, failing to completely wet the fibers. Furthermore, due to their low thermal degradation temperature, the sizing agents are prone to thermal degradation, generating gases that can cause delamination between the carbon fibers and the matrix resin, significantly reducing the quality of PEEK composites. Based on the principle of "like dissolves like," PEEK or its derivatives, due to their structural similarity to polyarylethers, are the best choice as an interfacial transition layer. However, PEEK is only soluble in concentrated sulfuric acid and insoluble in other reagents. Therefore, sulfonation or hydroxylation treatment of PEEK is necessary to prepare water-soluble carbon fiber sizing agents. Patent No. CN115125735 A discloses a method for preparing an acidified carbon nanotube-modified sulfonated polyether ether ketone aqueous sizing agent. This method uses nanofillers as modifiers, which is costly and difficult to scale up industrially, and has limited improvement on the interfacial properties of composite materials. Patent No. CN 113403849 A discloses a sizing agent for carbon fibers mixed with sulfonated polyether ether ketone and carbon nanotubes. This method uses N-methylpyrrolidone as the solvent of the main sizing agent, which is not environmentally friendly, and the solvent drying process is energy-intensive and costly.

[0004] Therefore, it is crucial to develop an aqueous sizing agent that is simple to prepare, has good storage and use stability, and excellent interfacial bonding performance between carbon fiber and polyether ether ketone. Summary of the Invention

[0005] This invention addresses the problem of poor interfacial properties in fiber-reinforced polyarylether composites by proposing an aqueous sizing agent suitable for improving the interfacial properties between fibers and the resin matrix. The sizing method involves surface treatment of the fibers to reduce their glass transition temperature (T0). g ) Sulfonated polyarylene ethers, high T g Sulfonated polyarylene ethers are compounded into an aqueous sizing agent, and the T of this invention... gThe distinction between high and low is limited to the relative glass transition temperatures of polyarylene ethers as described in this invention. The sizing agent of this invention contains low T... g Sulfonated polyarylethers and high T g Sulfonated polyarylethers can both self-emulsify in water to form hydrophilic microparticles, which can be adsorbed onto the carbon fiber surface. After sizing, the two types of microparticles accumulate on the carbon fiber surface to form a sizing agent layer. Due to high T g Sulfonated polyarylether resins contain bisphenol-like structures with large-volume side groups or spatially twisted structures in their main chain, exhibiting weak chain segment mobility and a glass transition temperature higher than that of low-T. g Sulfonated polyarylethers. During the heating process of composite material molding, low T... g Sulfonated polyarylether microparticles are the first to undergo changes in viscosity, such as creeping or flowing, making it easier for the matrix resin liquid to wet them; due to high T... g Sulfonated polyarylethers have higher glass transition temperatures, so their microparticles undergo creeping or flowing later or less frequently during the composite molding process. This allows them to act as a scaffold supporting the microparticle accumulation structure, providing a good channel for the matrix resin to fully impregnate the slurry layer on the fiber surface. Therefore, the matrix resin exhibits different impregnation behaviors in areas covered and accumulated by different types of microparticles on the carbon fiber surface, thus forming a mechanically interlocking structure at the fiber / matrix resin interface and enhancing the composite interface.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] A water-based sizing agent for carbon fibers, comprising component 1 sulfonated polyarylene ether A, component 2 sulfonated polyarylene ether B, and deionized water. Both sulfonated polyarylene ether A and sulfonated polyarylene ether B can self-emulsify in water to form hydrophilic microparticles, which can be adsorbed onto the carbon fiber surface. After sizing, the two types of microparticles accumulate on the carbon fiber surface to form a sizing agent layer. Based on a total mass of 100 parts, the sizing agent comprises:

[0008] Component 1: 0.1-15 parts of sulfonated polyarylene ether A, Component 2: 0.1-10 parts of sulfonated polyarylene ether B, and 75-99.8 parts of deionized water.

[0009] The structural formula of the sulfonated polyarylene ether A is shown in (1):

[0010] (1)

[0011] Where m≥0, n>0. R1, R2, R3, R4, R5, R6, R7, R8, R9, R 10 R 11 R 12 R 13 R 14 R 15 R16 It can be hydrogen, hydrogen sulfonate, or salt sulfonate.

[0012] Preferably, in the structural formula (1) of the sulfonated polyarylene ether A, R1, R2, R3, R4, R5, R6, R7, R8, R9, R 10 R 11 R 12 R 13 R 14 R 15 R 16 It is one or more of hydrogen, hydrogen sulfonate, and sodium sulfonate.

[0013] Preferably, in the structural formula (1) of the sulfonated polyarylene ether A, R2, R4, R5, R7, R... 10 R 12 R 13 R 15 For hydrogen, R1, R3, R6, R8, R9, R 11 R 14 R 16 It is one or more of hydrogen, hydrogen sulfonate and sodium sulfonate, and includes at least one hydrogen sulfonate and one sodium sulfonate.

[0014] The structures of —Ar0— and —Ar1— are produced by the reaction of the corresponding aromatic bisphenol monomers or diphenols, and are determined by the structure of the selected aromatic bisphenol monomer or diphenol. The structure of —Ar0— is selected from any one or more of the following:

[0015] 1, 2, 1, 3, or 1, 4;

[0016] 2,2' bits or 4,4' bits;

[0017] 1, 4 bits; 1, 5 bits; 1, 6 bits; 2, 6 bits; or 2, 7 bits;

[0018] 3, 3' bit or 4, 4' bit;

[0019] 3, 3' bit or 4, 4' bit;

[0020] 3, 3' bit or 4, 4' bit;

[0021] 3, 3' bit or 4, 4' bit;

[0022] , 3, 3′ bit or 4, 4′ bit.

[0023] The structure of —Ar1— is selected from one or more of the following:

[0024]

[0025] Among them, R 17 R 18 R 19 R 20 It can be one or more of hydrogen, hydrogen sulfonate, salt sulfonate, phenyl, phenyl derivative, hydroxyl, amino, carboxyl, cyano, alkyl, and alkoxy. The alkyl or alkyl derivative contains 1 to 30 carbon atoms and is either straight-chain or branched.

[0026] Preferably, the structure of —Ar0— is one or more of the following structures:

[0027] (a)

[0028] (b)

[0029] (c)

[0030] Preferably, in —Ar0—, structure (a) is 1, 4 bits, and structures (b) and (c) are 4, 4′ bits.

[0031] Preferably, in the structure —Ar0—, R 17 R 18 It is one or more of hydrogen, hydrogen sulfonate, or sodium sulfonate.

[0032] Preferably, the structure of —Ar1— is one or more of the following structures:

[0033] (d)

[0034] (e)

[0035] (f)

[0036] Preferably, in —Ar1—, structure (d) is 1, 4 bits, and structures (e) and (f) are 4, 4′ bits.

[0037] Preferably, in the structure of —Ar1—, R 19 R 20 It is one or more of hydrogen, hydrogen sulfonate, or sodium sulfonate.

[0038] The sulfonated polyarylene ether B has the structural formula shown in (2):

[0039] (2)

[0040] Where m≥0, n>0, p≥0. R 21 R 22 R 23 R 24 R 25 R 26 R 27 R 28 R 30 It can be any one or more of hydrogen, hydrogen sulfonate, or salt sulfonate. R 29 It can be any one or more of hydrogen, carboxyl, carboxylic acid derivatives, hydroxyl, methyl, methoxy or cyano.

[0041] Preferably, in the structural formula (2) of the sulfonated polyarylene ether B, R 21 R 22 R 23 R 24 For hydrogen, R 25 R 26 R 27 R 28 R 30 It is one or more of hydrogen, hydrogen sulfonate, and sodium sulfonate. R 29 It is one or more of carboxylic acids, sodium carboxylate, or cyano groups. The structures of —Ar2—, —Ar3—, and —Ar4— are produced by the reaction of the corresponding aromatic bisphenol monomer or bisphenol-like monomer, and are determined by the structure of the selected aromatic bisphenol monomer or bisphenol-like monomer. —Ar2—, —Ar3—, and —Ar4— can be the same or different. The —Ar2—, —Ar3—, and —Ar4— structures must contain one or more of the following structures:

[0042]

[0043] It can also contain the following structure:

[0044] 1, 2, 1, 3, or 1, 4;

[0045] 2, 2' bits or 4, 4' bits;

[0046] 1, 4 bits; 1, 5 bits; 1, 6 bits; 2, 6 bits; or 2, 7 bits;

[0047] 3, 3' bit or 4, 4' bit;

[0048] 3, 3' bit or 4, 4' bit;

[0049] 3, 3' bit or 4, 4' bit;

[0050] 3, 3' bit or 4, 4' bit;

[0051] , 3, 3′ bit or 4, 4′ bit.

[0052] Preferably, —Ar2—, —Ar3—, —Ar4— are one or more of the following structures (g), (h) or (i), and may also include structures (j), (k) or (l).

[0053] (g)

[0054] (h)

[0055] (i)

[0056] (j)

[0057] (k)

[0058] (l)

[0059] Preferably, in —Ar2—, —Ar3—, and —Ar4—, structure (i) is 1, 4 bits, and structures (j) and (k) are 4, 4′ bits.

[0060] Among them, R 31 R 32 R 33 R 34 R 35 R 36 It can be one or more of hydrogen, hydrogen sulfonate, salt sulfonate, halogen substituent, phenyl, phenoxy, hydroxy, amino, carboxyl, cyano, alkyl, and alkoxy, wherein the alkyl or alkoxy group contains 1 to 30 carbon atoms and is straight-chain or branched. It can also be a product of further sulfonation of the above structure.

[0061] Preferably, R 31 R 32 R 33 R 34 R 35 R 36 It is one or more of hydrogen, hydrogen sulfonate, or sodium sulfonate.

[0062] Furthermore, the number-average molecular weight of the sulfonated polyarylene ether A ranges from 1,000 to 150,000; each repeating unit contains 0.8 to 5.0 hydrogen sulfonate or salt sulfonate groups, with a particle size of 5 to 500 nm.

[0063] Furthermore, the number-average molecular weight of the sulfonated polyarylene ether B ranges from 1,000 to 150,000; each repeating unit contains 0.8 to 5.0 hydrogen sulfonate or salt sulfonate groups, with a particle size of 5 to 500 nm.

[0064] Preferably, the sulfonated polyarylene ether A has a number-average molecular weight of 5,000 to 50,000, each repeating unit contains 0.9 to 2.5 hydrogen sulfonate or salt sulfonate groups, and the particle size is 10 to 300 nm.

[0065] Preferably, the sulfonated polyarylene ether B has a number-average molecular weight of 5,000 to 50,000, each repeating unit contains 0.9 to 2.5 hydrogen sulfonate or salt sulfonate groups, and the particle size is 10 to 300 nm.

[0066] Furthermore, components 1 and 2 described in this invention are not limited to the substances mentioned above. Component 1 may also be polyacrylic acid, polyacrylamide, polyvinyl alcohol, or polyurethane, polyamide, polycarbonate, polylactic acid, sodium polystyrene sulfonate, polyolefin, protein, polysaccharide, or derivatives thereof containing water-based groups. Component 2 may also be a polymer with a cross-linked structure and water-based groups, such as lignin or derivatives thereof.

[0067] Furthermore, any one of component 1 or any one of component 2 can also constitute an aqueous sizing agent, but it still needs to meet the T requirement of one component. g The value is higher than that of another component.

[0068] The principle analysis of this invention: Both sulfonated polyarylene ether A and sulfonated polyarylene ether B can self-emulsify in water to form hydrophilic microparticles, which can be adsorbed on the carbon fiber surface. After sizing, the two types of microparticles accumulate on the carbon fiber surface to form a sizing agent layer. Because the main chain of sulfonated polyarylene ether B contains a bisphenol-like structure with large-volume side groups or spatially twisted structures, its chain segment mobility is weak, and its glass transition temperature is higher than that of sulfonated polyarylene ether A. During the heating process of composite material molding, the microparticles of sulfonated polyarylene ether A undergo viscous flow behavior changes first, such as creeping or flowing, making it easier for the matrix resin liquid to wet them. Sulfonated polyarylene ether B, due to its higher glass transition temperature, exhibits creeping or flowing behavior later or is less likely to do so during composite material molding. This allows it to act as a scaffold supporting the microparticle accumulation structure, providing a good channel for the matrix resin to fully wet the sizing agent layer. Therefore, the matrix resin forms different wetting behaviors in the areas covered and accumulated by different types of microparticles on the carbon fiber surface, thus forming a mechanically interlocking structure at the fiber / matrix resin interface layer, thereby enhancing the interface of the composite material.

[0069] The present invention discloses a method for preparing an aqueous sizing agent for carbon fiber. The aqueous sizing agent, based on a total weight of 100 parts, includes 0.1-15 parts by weight of sulfonated polyarylene ether A and 0.1-10 parts by weight of sulfonated polyarylene ether B, with the remaining parts by weight being deionized water.

[0070] A water-based sizing agent is prepared by mixing 0.1-15 parts by weight of sulfonated polyarylene ether A and 0.1-10 parts by weight of sulfonated polyarylene ether B in solid form and then adding the mixture to deionized water. Alternatively, 0.1-15 parts by weight of sulfonated polyarylene ether A can be mixed with deionized water first, followed by the addition of 0.1-10 parts by weight of sulfonated polyarylene ether B.

[0071] Preferably, at 15-80°C, 0.1-15 parts by weight of sulfonated polyarylene ether A are dissolved in 5-37.5 parts by weight of deionized water to obtain component 1 solution, and 0.1-10 parts by weight of sulfonated polyarylene ether B are dissolved in the remaining parts by weight of deionized water to obtain component 2 solution. Component 1 solution and component 2 solution are mixed to obtain an aqueous sizing agent.

[0072] An application of a water-based carbon fiber sizing agent involves sizing the fiber with the sizing agent, and then hot-pressing the sized fiber with polyarylether resin to obtain a fiber-reinforced polyarylether resin composite material.

[0073] Furthermore, the sizing time is 30~1200 seconds, and the sizing temperature is 20~30℃.

[0074] Furthermore, the polyarylether resin is preferably any one of polyetheretherketone, polyetherketoneketone, polyetherethersulfone, polyetherketone, polyethersulfone, polyetherketone, polyethersulfone, polyetheretherketoneketone, polyethersulfoneketone, or polyetherketoneetherketoneketone, or it may also be any one of polyamide, polyetherimide, polysulfone, or polyphenylene sulfide.

[0075] Furthermore, the fibers can be unidirectional continuous fibers, fiber braids, chopped fibers, long fibers, and fiber mats.

[0076] Furthermore, the sizing agent may also contain a small amount of nonionic emulsifier.

[0077] Furthermore, the sizing agent can be mixed with common anionic and nonionic sizing agents to improve the wear resistance, temperature resistance, and other properties of the anionic and nonionic sizing agents.

[0078] Furthermore, the sizing agent can be used in combination with acidified or hydrophilic carbon nanotubes, graphene, or MXene containing hydroxyl, amino, or carboxyl groups to further enhance the interfacial strength and interlayer properties of the composite material.

[0079] Compared with the prior art, the present invention has the following beneficial effects:

[0080] (1) The aqueous sizing agent of the present invention contains components with good structural compatibility with the matrix resin. Therefore, during the molding process of the composite material, the matrix resin can fully impregnate the fiber after sizing with the sizing agent of the present invention to ensure good interfacial compatibility between the matrix resin and the fiber. Due to the difference in main chain structure, the two components have different hydration capabilities, thereby self-emulsifying to form different microparticle structures, which stack on each other on the fiber surface during the sizing process. Moreover, due to the difference in main chain structure, the two components have different glass transition temperatures. During the molding process of the composite material, the component with a low glass transition temperature preferentially undergoes molecular chain movement during the heating process, and generates mutual entanglement with the molecular chains of the matrix resin. Its corresponding microparticles also begin to creep first. On the other hand, the molecular chains of the component with a high glass transition temperature move more slowly or later during the heating process, and the creep of its corresponding microparticles is also slower or later than that of the component with a low glass transition temperature. Therefore, during the composite molding process, when the matrix resin is compounded with it, it preferentially wets and fuses with the regions containing the sizing agent components (microparticles) with low glass transition temperatures, filling the gaps between the microparticles. Microparticles with high glass transition temperatures act as a scaffold structure to support their packing. As the temperature further increases, the matrix resin further wets the microparticles with high glass transition temperatures. The different wetting behaviors of the matrix resin in different regions of the fiber surface create a mechanically interlocking structure at the fiber / matrix resin interface, thereby enhancing the composite material interface.

[0081] (2) The sizing agent solvent of the present invention is deionized water, which will not cause pollution to the environment. Moreover, the preparation method is simple and efficient, easy to repeat, and has good prospects for industrial application.

[0082] (3) The aqueous sizing agent of the present invention has the advantage of stable physicochemical properties. Because the main chain of the aqueous sizing agent of the present invention has abundant hydrolyzable ionizable groups and strong acid (salt) properties, it has excellent hydrophilicity and can self-emulsify to form charged microparticle structures. The interior of the microparticles consists of polymer segments that do not contain or contain a small amount of sulfonated groups, and the outer layer of the microparticles consists of sulfonate groups and polymer segments containing sulfonate groups. Moreover, this group has excellent chemical stability, so it has a very high absolute value of Zeta potential, which can ensure that the sizing agent does not agglomerate and form precipitation during storage.

[0083] (4) The water-based sizing agent of the present invention has a high thermal deformation temperature. Because the main chain of the molecular structure of the sizing agent component 2 of the present invention contains large-volume aromatic rings or heterocyclic rigid groups (fluorenyl, Cardo structure, diazanaphthone, indole ring, etc.), its glass transition temperature is higher than that of the sizing agent component that only has a benzene ring structure, which can significantly increase the overall thermal deformation temperature of the sizing agent.

[0084] (5) The water-based sizing agent described in this invention has excellent thermal stability, with a 5% thermal weight loss temperature exceeding 450°C. Therefore, it will not degrade during the molding and processing of composite materials, effectively preventing the fiber / resin interface from debonding, thereby significantly improving the interfacial properties of the composite material.

[0085] (6) The water-based sizing agent of the present invention has wear-resistant properties. Since the components of the sizing agent of the present invention all contain aromatic rings and aromatic heterocyclic groups, the sizing agent is endowed with good abrasion resistance properties, which can significantly reduce the amount of hairiness in the process of sizing carbon fiber yarn unwinding, improve the adaptability of the composite material manufacturing process of carbon fiber after sizing, and is especially suitable for the manufacturing process of carbon fiber and high viscosity thermoplastic resin composite, thereby improving the stability of composite process and finished product.

[0086] (7) The water-based sizing agent of the present invention has a flexibly adjustable particle size. Since the sizing agent of the present invention is soluble in both water and organic solvents, and since water and polar solvents have significantly different solvation capabilities, a combination of water and low-boiling-point organic solvents can be designed. This characteristic can be used to control the degree of expansion of the sizing agent molecular chains in solvents with different mixing ratios. Then, the low-boiling-point organic solvent can be removed by vacuum-assisted removal, thereby obtaining sizing agent microparticles of different sizes. Therefore, the stacking state of the microparticles of each component of the sizing agent on the carbon fiber surface can be easily controlled, thereby controlling the degree of mechanical interlocking between the matrix resin and the sizing agent. It can be adapted to matrix resins of different viscosities to obtain good fiber / resin interface properties.

[0087] (8) The aqueous sizing agent of the present invention has good biocompatibility. Because the main chain structure of the sizing agent components has excellent acid and alkali resistance and temperature resistance, and has chemically stable and non-toxic hydrophilic groups, the sizing agent has good biocompatibility and can be used in the preparation of medical implant composite materials. Attached Figure Description

[0088] Figure 1 Example 1 shows the particle size distribution of the water-based sizing agent.

[0089] Figure 2 These are scanning electron microscope images of the desized fibers and the sized fibers in Example 1.

[0090] Figure 3 shows scanning electron microscope images of desized fibers and sized fibers in Example 2.

[0091] Figure 4 shows scanning electron microscope images of desized fibers and sized fibers in Example 4.

[0092] Figure 5 shows the test results of the interlaminar shear strength of the composite materials measured in Examples 1-8 and Comparative Examples 1-8.

[0093] Figure 6 shows the test results of the flexural strength of the composite materials measured in Examples 1-8 and Comparative Examples 1-8.

[0094] Figure 7 shows the thermogravimetric curve of the water-based sizing agent resin in Example 1.

[0095] Figure 8 This is a schematic diagram of the present invention. Detailed Implementation

[0096] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. These embodiments are for illustrative purposes only and do not limit the scope of the invention. Various modifications or alterations can be made to this invention by those skilled in the art after reading the contents of this invention.

[0097] Example 1

[0098] Step 1: Dissolve 0.1 parts by weight of Component 1 resin in 10 parts by weight of deionized water at 15°C to obtain Component 1 solution. Component 1 resin has a number-average molecular weight of 10,000, and each repeating unit contains one sodium sulfonate ion. The average particle size of the resulting solution is 50 nm. The chemical structural formula of Component 1 is as follows:

[0099]

[0100] Step 2: Dissolve 7.5 parts by weight of component 2 resin in 82.4 parts by weight of deionized water at 15°C to obtain component 2 solution. Component 2 resin has a number-average molecular weight of 50,000, and each repeating unit contains 0.9 sodium sulfonate ions. The average particle size of the resulting solution is 300 nm. The chemical structural formula of component 2 is as follows:

[0101]

[0102] Step 3: Mix the component 1 solution and the component 2 solution continuously at 15°C to form a homogeneous solution.

[0103] Step 4: Immerse the desized carbon fiber in the water-based sizing agent from Step 3 for 1200 seconds at a sizing temperature of 25°C. After sizing, dry the sized carbon fiber at 120°C for 20 minutes to allow the moisture to evaporate completely. Then, hot-press the sized carbon fiber with polyetheretherketone resin to obtain the composite material.

[0104] The composite material obtained in Example 1 was tested, and the interlaminar shear strength and flexural strength of the composite material were measured to be 104 MPa and 2395 MPa, respectively.

[0105] Figure 1 This is a particle size distribution diagram of the two components of the water-soluble resin in Example 1 of the present invention. As can be seen from the diagram, component 1 with an average particle size of 7 nm and component 2 with an average particle size of 500 nm coexist in the water-based sizing agent.

[0106] Figure 2 The image shown is a scanning electron microscope image of the fiber sized with the aqueous sizing agent in Example 1 of this invention. It can be seen that after sizing, some grooves on the surface of the carbon fiber are filled with the sizing agent.

[0107] Figure 5 The interlaminar shear strength test results of the composite materials obtained in Examples 1-8 and Comparative Examples 1-8 of this invention show that the interlaminar shear strength of the carbon fiber composite material is significantly improved after treatment with the water-based sizing agent of the invention.

[0108] Figure 6 The results of the bending strength test of the composite materials obtained in Examples 1-8 and Comparative Examples 1-8 of this invention show that the bending strength of the carbon fiber composite material is significantly improved after treatment with the water-based sizing agent in the invention.

[0109] Figure 7 The thermogravimetric curve of the aqueous sizing agent prepared in Example 1 of this invention shows that the sizing agent has a 95% mass retention rate at 475℃.

[0110] Example 2

[0111] Step 1: Dissolve 5 parts by weight of Component 1 resin in 5 parts by weight of deionized water at 75°C to obtain Component 1 solution. Component 1 resin has a number-average molecular weight of 15,000, and each repeating unit contains 0.9 sodium sulfonate ions. The average particle size of the resulting solution is 300 nm. The chemical structural formula of Component 1 is as follows:

[0112]

[0113] Step 2: Dissolve 5 parts by weight of component 2 resin in 85 parts by weight of deionized water at 75°C to obtain component 2 solution. Component 2 resin has a number-average molecular weight of 14,000, and each repeating unit contains 2.3 sodium sulfonate groups. The average particle size of the resulting solution is 70 nm. The chemical structural formula of component 2 is as follows:

[0114]

[0115] Step 3: Mix the component 1 solution and the component 2 solution continuously at 75°C to form a homogeneous solution.

[0116] Step 4: Impregnate the desized basalt fibers in the water-based sizing agent from Step 3 for 600 seconds at a temperature of 30°C. After sizing, dry the sized carbon fibers at 120°C for 20 minutes to allow all moisture to evaporate. Then, hot-press the sized carbon fibers with polyetherketone resin to obtain the composite material.

[0117] The composite material obtained in Example 2 was tested, and the interlaminar shear strength and flexural strength of the composite material were measured to be 67 MPa and 1667 MPa, respectively.

[0118] Figure 3 shows scanning electron microscope images of desized fibers and sized fibers in Example 2.

[0119] Example 3

[0120] Step 1: Dissolve 0.3 parts by weight of Component 1 resin in 26 parts by weight of deionized water at 55°C to obtain Component 1 solution. Component 1 resin has a number-average molecular weight of 5000, and each repeating unit contains 1.1 hydrogen sulfonate ions. The average particle size of the resulting solution is 10 nm. The chemical structural formula of Component 1 is as follows:

[0121]

[0122] Step 2: Dissolve 4.5 parts by weight of component 2 resin in 69.2 parts by weight of deionized water at 55°C to obtain component 2 solution. Component 2 resin has a number-average molecular weight of 10,000, and each repeating unit contains one hydrogen sulfonate ion. The average particle size of the resulting solution is 50 nm. The chemical structural formula of component 2 is as follows:

[0123]

[0124] Step 3: Mix the component 1 solution and the component 2 solution continuously at 55°C to form a homogeneous solution.

[0125] Step 4: Immerse the desized carbon fiber cloth in the water-based sizing agent from Step 3 for 30 seconds at a sizing temperature of 27°C. After sizing, dry the sized carbon fiber cloth at 120°C for 20 minutes to allow the moisture to evaporate completely. Then, hot-press the sized carbon fiber cloth with polyetheretherketone-ketone resin to obtain the composite material.

[0126] The composite material obtained in Example 3 was tested, and the interlaminar shear strength was measured to be 55 MPa and the flexural strength to be 1226 MPa.

[0127] Figure 4 shows scanning electron microscope images of desized fibers and sized fibers in Example 4.

[0128] Example 4

[0129] Step 1: Dissolve 15 parts by weight of Component 1 resin in 37.5 parts by weight of deionized water at 80°C to obtain Component 1 solution. Component 1 resin has a number-average molecular weight of 50,000, and each repeating unit contains 2.5 sodium sulfonate groups. The average particle size of the resulting solution is 70 nm. The chemical structural formula of Component 1 is as follows:

[0130]

[0131] Step 2: Dissolve 0.1 parts by weight of component 2 resin in 47.4 parts by weight of deionized water at 80°C to obtain component 2 solution. Component 2 resin has a number-average molecular weight of 5000, and each repeating unit contains 2.5 sodium sulfonate groups. The average particle size of the resulting solution is 10 nm. The chemical structural formula of component 2 is as follows:

[0132]

[0133] Step 3: Mix the component 1 solution and the component 2 solution continuously at 80°C to form a homogeneous solution.

[0134] Step 4: Impregnate the desized glass fibers in the water-based sizing agent from Step 3 for 800 seconds at a sizing temperature of 21°C. After sizing, dry the sized carbon fibers at 120°C for 20 minutes to allow all moisture to evaporate. Then, hot-press the sized carbon fibers with polyetherketone resin to obtain the composite material.

[0135] The composite material obtained in Example 4 was tested, and the interlaminar shear strength and flexural strength of the composite material were measured to be 80 MPa and 1385 MPa, respectively.

[0136] Example 5

[0137] Step 1: Dissolve 7.5 parts by weight of Component 1 resin in 12 parts by weight of deionized water at 40°C to obtain Component 1 solution. Component 1 resin has a number-average molecular weight of 35,000, and each repeating unit contains 2.2 sodium sulfonate groups. The average particle size of the resulting solution is 10 nm. The chemical structural formula of Component 1 is as follows:

[0138]

[0139] Step 2: Dissolve 10 parts by weight of component 2 resin in 70.5 parts by weight of deionized water at 40°C to obtain component 2 solution. Component 2 resin has a number-average molecular weight of 7500, and each repeating unit contains 0.9 sodium sulfonate ions. The average particle size of the resulting solution is 15 nm. The chemical structural formula of component 2 is as follows:

[0140]

[0141] Step 3: Mix the component 1 solution and the component 2 solution continuously at 40°C to form a homogeneous solution.

[0142] Step 4: Immerse the desized carbon fiber in the water-based sizing agent from Step 3 for 300 seconds at a sizing temperature of 21°C. After sizing, dry the sized carbon fiber at 120°C for 20 minutes to allow all moisture to evaporate. Then, hot-press the sized carbon fiber with polyetheretherketone-ketone resin to obtain the composite material.

[0143] The composite material obtained in Example 5 was tested, and the interlaminar shear strength and flexural strength of the composite material were measured to be 71 MPa and 1868 MPa, respectively.

[0144] Example 6

[0145] The other components required by this invention, the aqueous sizing agent and the resin matrix, are embodied in Example 6. The steps are as follows:

[0146] Step 1: Dissolve 12.5 parts by weight of Component 1 resin in 37.5 parts by weight of deionized water at 20°C to obtain Component 1 solution. Component 1 resin has a number-average molecular weight of 8000, and each repeating unit contains 1.0 hydrogen sulfonate group and 0.5 sodium sulfonate group. The average particle size of the resulting solution is 250 nm. The chemical structural formula of Component 1 is as follows:

[0147]

[0148] Step 2: Dissolve 0.3 parts by weight of component 2 resin in 49.7 parts by weight of deionized water at 20°C to obtain component 2 solution. Component 2 resin has a number-average molecular weight of 20,000, and each repeating unit contains 1.2 hydrogen sulfonate groups. The average particle size of the resulting solution is 30 nm. The chemical structural formula of component 2 is as follows:

[0149]

[0150] Step 3: Mix the component 1 solution, component 2 solution and 1 part by weight of nonionic polyacrylamide at 20°C with constant stirring to form a homogeneous solution.

[0151] Step 4: Immerse the desized carbon fiber in the water-based sizing agent from Step 3 for 1000 seconds at a sizing temperature of 20°C. After sizing, dry the sized carbon fiber at 120°C for 20 minutes to allow all moisture to evaporate. Then, hot-press the sized carbon fiber with polyethersulfone resin to obtain the composite material.

[0152] The composite material obtained in Example 6 was tested, and the interlaminar shear strength and flexural strength of the composite material were measured to be 45 MPa and 1190 MPa, respectively.

[0153] Example 7

[0154] The other components required by this invention, the aqueous sizing agent and the resin matrix, are embodied in Example 7. The steps are as follows:

[0155] Step 1: Dissolve 1 part by weight of component 1 resin in 30 parts by weight of deionized water at 60°C to obtain component 1 solution. The number average molecular weight of component 1 resin is 20,000, and each repeating unit contains 0.9 sodium sulfonate ions. The average particle size of the resulting solution is 30 nm. The chemical structural formula of component 1 is as follows:

[0156]

[0157] Step 2: Dissolve 0.1 parts by weight of component 2 resin in 68.9 parts by weight of deionized water at 60°C to obtain component 2 solution. Component 2 resin has a number-average molecular weight of 15,000, and each repeating unit contains 1.8 sodium sulfonate groups. The average particle size of the resulting solution is 10 nm. The chemical structure of component 2 is as follows:

[0158]

[0159] Step 3: Mix the solution of component 1, the solution of component 2 and 2 parts by weight of carboxylated carbon nanotubes at 60°C with constant stirring to form a solution.

[0160] Step 4: Impregnate the desized basalt fibers in the water-based sizing agent from Step 3 for 750 seconds at a sizing temperature of 22°C. After sizing, dry the sized carbon fibers at 120°C for 20 minutes to allow all moisture to evaporate. Then, hot-press the sized carbon fibers with polyetherketone resin to obtain the composite material.

[0161] The composite material obtained in Example 7 was tested, and the interlaminar shear strength was measured to be 64 MPa and the flexural strength to be 1706 MPa.

[0162] Example 8

[0163] The other components required by this invention, the aqueous sizing agent and the resin matrix, are embodied in Example 8. The steps are as follows:

[0164] Step 1: Dissolve 2 parts by weight of polyurethane in 48 parts by weight of deionized water to prepare component 1 solution. The number average molecular weight of polyurethane is 40,000 and the average particle size of the solution is 130 nm.

[0165] Step 2: Dissolve 0.1 parts by weight of sodium lignosulfonate in 49.9 parts by weight of deionized water to prepare component 2 solution, which has a number average molecular weight of 60,000 and an average particle size of 500 nm.

[0166] Step 3: Stir the solutions prepared in Step 1 and Step 2 continuously at 20°C to form a homogeneous solution.

[0167] Step 4: Impregnate the desized carbon fiber in the water-based sizing agent from Step 3 for 30 seconds at a temperature of 25°C. After impregnation, dry the sized carbon fiber at 120°C for 20 minutes to allow all moisture to evaporate. Then, hot-press the sized carbon fiber with nylon 6 resin to obtain the composite material.

[0168] The composite material obtained in Example 8 was tested, and the interlaminar shear strength and flexural strength of the composite material were measured to be 51 MPa and 1403 MPa, respectively.

[0169] Comparative Example 1

[0170] In Comparative Example 1, untreated carbon fibers and polyetheretherketone resin were hot-pressed to obtain a composite material.

[0171] The composite material obtained in Comparative Example 1 was tested, and the interlaminar shear strength and flexural strength of the composite material were measured to be 45 MPa and 1352 MPa, respectively.

[0172] Comparative Example 2

[0173] In Comparative Example 2, untreated basalt fibers and polyether ketone resin were hot-pressed to obtain a composite material.

[0174] The composite material obtained in Comparative Example 2 was tested, and the interlaminar shear strength and flexural strength of the composite material were measured to be 42 MPa and 1206 MPa, respectively.

[0175] Comparative Example 3

[0176] In Comparative Example 3, untreated carbon fiber cloth and polyetheretherketone resin were hot-pressed to obtain a composite material.

[0177] The composite material obtained in Comparative Example 3 was tested, and the interlaminar shear strength was measured to be 30 MPa and the flexural strength to be 1002 MPa.

[0178] Comparative Example 4

[0179] In Comparative Example 4, untreated glass fiber and polyetherketone resin were hot-pressed to obtain a composite material.

[0180] The composite material obtained in Comparative Example 4 was tested, and the interlaminar shear strength and flexural strength of the composite material were measured to be 29 MPa and 907 MPa, respectively.

[0181] Comparative Example 5

[0182] In Comparative Example 5, untreated carbon fibers and polyetheretherketone resin were hot-pressed to obtain a composite material.

[0183] The composite material obtained in Comparative Example 5 was tested, and the interlaminar shear strength and flexural strength of the composite material were measured to be 47 MPa and 878 MPa, respectively.

[0184] Comparative Example 6

[0185] In Comparative Example 6, untreated carbon fibers and polyethersulfone resin were hot-pressed to obtain a composite material.

[0186] The composite material obtained in Comparative Example 6 was tested, and the interlaminar shear strength and flexural strength of the composite material were measured to be 31 MPa and 982 MPa, respectively.

[0187] Comparative Example 7

[0188] In Comparative Example 7, untreated basalt fibers and polyetherketone resin were hot-pressed to obtain a composite material.

[0189] The composite material obtained in Comparative Example 7 was tested, and the interlaminar shear strength and flexural strength of the composite material were measured to be 54 MPa and 1385 MPa, respectively.

[0190] Comparative Example 8

[0191] In Comparative Example 8, untreated carbon fiber and nylon 6 resin were hot-pressed to obtain a composite material.

[0192] The composite material obtained in Comparative Example 8 was tested, and the interlaminar shear strength and flexural strength of the composite material were measured to be 35 MPa and 935 MPa, respectively.

[0193] In summary, the following conclusions can be drawn: by comparing Examples 1 to 8, it can be found that composite materials with different mechanical properties can be obtained by changing the chemical structure of sulfonated polyarylene ether A and sulfonated polyarylene ether B resins.

[0194] By comparing the interlaminar shear strength and flexural strength data of Examples 1-8 with those of Comparative Examples 1-8, it can be seen that the water-based sizing agent provided in this invention can effectively improve the interfacial properties of composite materials.

[0195] It should be understood that the application of this invention is not limited to the examples above, and the design concept of this invention is not limited thereto. Any non-substantial modifications made to this invention using this concept shall be considered as infringing upon the scope of protection of this invention. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of this invention without departing from the content of the technical solution of this invention shall still fall within the scope of protection of the technical solution of this invention.

Claims

1. A sizing agent for water-based carbon fibers, characterized in that, The sizing agent includes component 1, component 2 and deionized water. Both component 1 and component 2 can self-emulsify in water to form hydrophilic microparticles, which can be adsorbed on the carbon fiber surface. After sizing, the two types of microparticles accumulate on the carbon fiber surface to form a sizing agent layer. Component 1 is sulfonated polyarylene ether A; component 2 is sulfonated polyarylene ether B. The structural formula of the sulfonated polyarylene ether A is shown in (1): (1) Where m≥0, n>0; R1, R2, R3, R4, R5, R6, R7, R8, R9, R 10 R 11 R 12 R 13 R 14 R 15 R 16 All can be hydrogen, hydrogen sulfonate or salt sulfonate, and they can be the same or different; the structures of —Ar0— and —Ar1— are generated by the reaction of the corresponding aromatic bisphenol monomers and are determined by the structure of the selected aromatic bisphenol monomer. The structure of —Ar0— is selected from any one or more of the following: 1, 2, 1, 3, or 1, 4 digits; , 2, 2' bits or 4, 4' bits; , 1, 4 bits, 1, 5 bits, 1, 6 bits, 2, 6 bits, or 2, 7 bits; , 3, 3' bits or 4, 4' bits; , 3, 3' bits or 4, 4' bits; , 3, 3' bits or 4, 4' bits; , 3, 3' bits or 4, 4' bits; , 3, 3' bits or 4, 4' bits; The structure of —Ar1— is selected from any one or more of the following: Among them, R 17 R 18 R 19 R 20 It can be one or more of hydrogen, hydrogen sulfonate, salt sulfonate, phenyl, phenyl derivative, hydroxyl, amino, carboxyl, cyano, alkyl and alkoxy; wherein the alkyl or phenyl derivative contains 1 to 30 carbon atoms and is straight or branched. The sulfonated polyarylene ether B has the structural formula shown in (2): (2) Where m≥0, n>0, p≥0; R 21 R 22 R 23 R 24 R 25 R 26 R 27 R 28 R 30 All can be any one or more of hydrogen, hydrogen sulfonate, or salt sulfonate, and can be the same or different; R 29 It can be hydrogen, carboxyl, carboxylic acid derivative, hydroxyl, methyl, methoxy or cyano; the structure of —Ar2—, —Ar3—, —Ar4— is generated by the reaction of the corresponding aromatic bisphenol monomer or bisphenol-like monomer, and is determined by the structure of the selected aromatic bisphenol monomer or bisphenol-like monomer. —Ar2—, —Ar3—, —Ar4— can be the same or different; The aforementioned —Ar2—, —Ar3—, —Ar4— structures must include one or more of the following structures: It can also contain the following structure: 1, 2, 1, 3, or 1, 4 digits; , 2, 2' bits or 4, 4' bits; , 1, 4 bits, 1, 5 bits, 1, 6 bits, 2, 6 bits, or 2, 7 bits; , 3, 3' bits or 4, 4' bits; , 3, 3' bits or 4, 4' bits; , 3, 3' bits or 4, 4' bits; , 3, 3' bits or 4, 4' bits; , 3, 3' bits or 4, 4' bits; Among them, R 31 R 32 R 33 R 34 R 35 R 36 It is one or more of hydrogen, hydrogen sulfonate, salt sulfonate, halogen substituent, phenyl, phenoxy, hydroxy, amino, carboxyl, cyano, alkyl and alkoxy, wherein the alkyl or alkoxy contains 1 to 30 carbon atoms, and is straight or branched; or it is a product of further sulfonation of the above structure.

2. The sizing agent for water-based carbon fiber according to claim 1, characterized in that, The glass transition temperature of component 2 is higher than that of component 1.

3. The sizing agent for water-based carbon fiber according to claim 1, characterized in that, Based on a total mass of 100 parts, the sizing agent comprises: Component 1: 0.1-15 parts of sulfonated polyarylene ether A; Component 2: 0.1-10 parts of sulfonated polyarylene ether B; and 75-99.8 parts of deionized water.

4. The sizing agent for water-based carbon fiber according to claim 3, characterized in that, The sulfonated polyarylene ether A has a number-average molecular weight range of 1,000 to 150,000; each repeating unit contains 0.8 to 5.0 hydrogen sulfonate or salt sulfonate ions, and the particle size is 5 to 500 nm; the sulfonated polyarylene ether B has a number-average molecular weight range of 1,000 to 150,000; each repeating unit contains 0.8 to 5.0 hydrogen sulfonate or salt sulfonate ions, and the particle size is 5 to 500 nm.

5. The sizing agent for water-based carbon fiber according to claim 4, characterized in that, The sulfonated polyarylene ether A contains 0.9 to 2.5 hydrogen sulfonate or salt sulfonate groups; the sulfonated polyarylene ether B contains 0.9 to 2.5 hydrogen sulfonate or salt sulfonate groups.

6. The application of a sizing agent for waterborne carbon fiber according to any one of claims 1-5, characterized in that, The fiber is sized using the sizing agent, and the sized fiber and polyarylether resin are hot-pressed into a composite material to obtain a fiber-reinforced polyarylether resin composite material.

7. The application of the sizing agent for waterborne carbon fiber according to claim 6, characterized in that, The sizing time is 30~1200 seconds, and the sizing temperature is 20~30℃; the polyarylether resin is any one of polyetheretherketone, polyetherketoneketone, polyetherethersulfone, polyetherketone, polyethersulfone, polyetherketone, polyethersulfoneketone, polyethersulfoneketone, or polyetherketoneetherketoneketone; the fiber is unidirectional continuous fiber, fiber braid, chopped fiber, long fiber, or fiber felt.

8. The application of the sizing agent for waterborne carbon fiber according to claim 6, characterized in that: The sizing agent may also contain a small amount of nonionic emulsifier; Alternatively, the sizing agent can be mixed with common anionic and nonionic sizing agents to improve the wear resistance and temperature resistance of the anionic and nonionic sizing agents. Alternatively, the sizing agent can be used in combination with acidified or hydrophilic carbon nanotubes, graphene, or MXene containing hydroxyl, amino, or carboxyl groups to improve the interfacial strength and interlayer properties of the composite material.

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