Carbon fiber reinforced polyether-ether-ketone composite material and preparation method thereof

Abstract

The invention relates to the technical field of composite material preparation, in particular to a carbon fiber reinforced polyether-ether-ketone composite material and a preparation method thereof. The method comprises the following steps: a) providing a carbon fiber material which is made of continuous carbon fibers and has a plurality of parallel strands, and dipping the carbon fiber material in a suspension of polyether-ether-ketone; b) drying and melting so that the carbon fiber material and the polyether-ether-ketone are combined and cured to obtain a first cured material; c) contacting aerosol containing polyether-ether-ketone with the first cured substance, and curing at high temperature to obtain a second cured substance; and d) carrying out molding treatment on the second cured product.

Description

Technical Field

[0001] The present disclosure relates to the technical field of composite material preparation, and in particular to a carbon fiber reinforced polyetheretherketone composite material and a preparation method thereof. Background Art

[0002] Carbon fiber reinforced polyetheretherketone (PEEK) composite material is a thermoplastic composite material made of PEEK as a resin matrix and carbon fiber material as a reinforcement. Compared with commonly used thermosetting composite materials, it has the characteristics of good impact resistance, recyclability and reprocessing, high production efficiency, high damage tolerance, high temperature resistance and chemical resistance. It is widely used in high-end fields such as military industry and aerospace, and has become a hot research topic at home and abroad in recent years. The production process of carbon fiber reinforced PEEK material is divided into two types: dry method and wet method. The dry process includes powder impregnation method, film lamination method, etc., and the wet process includes melt impregnation method, suspension impregnation method, etc. Among them, the powder suspension method has the characteristics of little damage to the fiber and uniform distribution of the resin, and is the current mainstream method. However, there are also problems such as low resin content on the surface of the material, poor interlayer interface strength after molding, and high porosity.

[0003] CN 111057346 B discloses a carbon fiber reinforced PEEK unidirectional tape and a preparation method thereof, which adopts a suspension method to impregnate carbon fiber with a resin suspension and then melt and mold it for winding. After the unidirectional tape is molded, the resin can be evenly distributed inside the unidirectional tape, but the surface resin content is insufficient. In subsequent processing, especially in the process of laying the wire and laying the tape, it is difficult to ensure the interface strength between the layers. CN 105479912A discloses a process for producing continuous fiber reinforced thermoplastic resin unidirectional tape by a film lamination method, which adopts resin film and carbon fiber molding. Although this method can significantly increase the resin content on the surface of the material, it is difficult to evenly penetrate into the material due to the poor fluidity of the resin after melting, and the product performance is defective. CN 116175817 A discloses a preparation method for continuously producing carbon fiber cloth reinforced thermoplastic composite unidirectional tape, which is formed by a powder suspension method and then a film method is used to increase the resin content on the surface of the unidirectional tape. The production efficiency of this process is low. At the same time, the thickness of the thermoplastic resin film is above 20 μm, which leads to a decrease in the fiber component of the unidirectional tape and affects the mechanical properties of the unidirectional tape. Summary of the invention

[0004] This disclosure covers the following technical solutions:

[0005] The present disclosure provides a method for preparing a carbon fiber reinforced polyetheretherketone composite material, which comprises:

[0006] a) providing a carbon fiber material having a plurality of parallel strands made of continuous carbon fibers and impregnating the carbon fiber material in a suspension of polyetheretherketone;

[0007] b) drying the melt to allow the carbon fiber material to be combined with the polyetheretherketone and solidified to obtain a first solidified product;

[0008] c) contacting the first solidified product with an aerosol containing polyetheretherketone, and curing the aerosol at a high temperature to obtain a second solidified product;

[0009] d) subjecting the second solidified product to molding.

[0010] In yet another aspect of the present disclosure, it relates to a carbon fiber reinforced polyetheretherketone composite material prepared by the method as described above.

[0011] In yet another aspect of the present disclosure, it relates to use of the carbon fiber reinforced polyetheretherketone composite material as described above in manufacturing a three-dimensional component.

[0012] The disclosed method can significantly improve the interlayer interface strength, and improve the interlayer shear strength and post-impact compression strength without substantially affecting the tensile strength. The preparation method has a simple process and low production cost, and not only retains the advantages of the wet process in terms of low fiber damage and good impregnation effect, but also the surface resin layer can fill the internal pores of the unidirectional tape caused by the evaporation of water in the drying and melting process in the wet process. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to more clearly illustrate the specific embodiments of the present disclosure or the technical solutions in the prior art, the drawings required for use in the specific embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0014] Figure 1 Metallographic images of the cross-sections of the unidirectional tapes prepared in Comparative Example 1 (A), Example 4 (B) and Example 5 (C) of the present disclosure. DETAILED DESCRIPTION

[0015] References to embodiments of the present disclosure will now be provided in detail, one or more examples of which are described below. Each example is provided as an explanation rather than a limitation of the present disclosure. In fact, it will be apparent to those skilled in the art that various modifications and variations may be made to the present disclosure without departing from the scope or spirit of the present disclosure. For example, a feature illustrated or described as part of one embodiment may be used in another embodiment to produce a further embodiment.

[0016] Unless otherwise indicated, the meaning of all terms (including technical and scientific terms) used to disclose the present disclosure is the same as that commonly understood by those of ordinary skill in the art to which the present disclosure belongs. By way of further guidance, the following definitions are used to better understand the teachings of the present disclosure. The terms used herein in the specification of the present disclosure are only for the purpose of describing specific embodiments and are not intended to limit the present disclosure.

[0017] The terms "and / or", "or / and", and "and / or" used herein have a selection range that includes any one of two or more related listed items, and also includes any and all combinations of related listed items, wherein the any and all combinations include any two related listed items, any more related listed items, or a combination of all related listed items. It should be noted that when at least three items are connected by at least two conjunctions selected from "and / or", "or / and", and "and / or", it should be understood that in the present disclosure, the technical solution undoubtedly includes technical solutions that are all connected by "logical and", and undoubtedly includes technical solutions that are all connected by "logical or". For example, "A and / or B" includes three parallel solutions of A, B and A+B. For example, the technical solution of "A, and / or, B, and / or, C, and / or, D" includes any one of A, B, C, and D (that is, the technical solution that is all connected by "logical OR"), and also includes any and all combinations of A, B, C, and D, that is, the combination of any two or any three of A, B, C, and D, and also includes the combination of four of A, B, C, and D (that is, the technical solution that is all connected by "logical AND").

[0018] As used in this disclosure, the terms "comprising," "including," and "including" are synonymous and are inclusive or open-ended and do not exclude additional, unrecited members, elements, or method steps.

[0019]

[0013] Numerical ranges recited in this disclosure as endpoints include all numbers and fractions subsumed within that range, as well as the recited endpoints.

[0020] As used herein, reference to "about" a value or parameter includes (and describes) embodiments directed to the value or parameter itself. For example, description referring to "about X" includes description of "X".

[0021] The present disclosure relates to concentration values, and the meaning includes fluctuations within a certain range. For example, fluctuations can be allowed within a corresponding precision range. For example, 2%, a fluctuation within the range of ±0.1% can be allowed. For values ​​that are large or do not require too fine control, the meaning is also allowed to include greater fluctuations. For example, 100mM, fluctuations within the range of ±1%, ±2%, ±5%, etc. can be allowed. Involving molecular weight, the meaning is allowed to include fluctuations of ±10%.

[0022] As used herein, the singular articles "a," "an," and "the" include plural referents unless otherwise indicated.

[0023] In the present disclosure, descriptions such as "plurality" and "multiple" refer to quantities greater than or equal to 2 unless otherwise specified.

[0024] In the present disclosure, the technical features described in an open manner include closed technical solutions composed of the listed features, and also include open technical solutions containing the listed features.

[0025] In the present disclosure, "preferred", "better", "more preferred", and "suitable" are only used to describe implementation methods or examples with better effects, and it should be understood that they do not constitute a limitation on the scope of protection of the present disclosure. In the present disclosure, "optionally", "optional", and "optional" mean optional, that is, any one of the two parallel schemes of "yes" or "no". If multiple "options" appear in a technical solution, unless otherwise specified and there is no contradiction or mutual restriction, each "optional" is independent.

[0026] All documents mentioned in the present disclosure are cited as references in the present disclosure, just as each document is cited as a reference individually. Unless they conflict with the invention objectives and / or technical solutions of the present disclosure, the cited documents involved in the present disclosure are cited with all their contents and all their purposes. When the present disclosure involves cited documents, the definitions of relevant technical features, terms, nouns, phrases, etc. in the cited documents are also cited. When the present disclosure involves cited documents, the examples and preferred methods of the cited relevant technical features may also be incorporated into the present disclosure as references, but are limited to the implementation of the present disclosure. It should be understood that when the cited content conflicts with the description in the present disclosure, the present disclosure shall prevail or be modified adaptively according to the description of the present disclosure.

[0027] A first aspect of the present disclosure relates to a method for preparing a carbon fiber reinforced polyetheretherketone composite material, comprising:

[0028] a) providing a carbon fiber material having a plurality of parallel strands made of continuous carbon fibers and impregnating the carbon fiber material in a suspension of polyetheretherketone;

[0029] b) drying the melt to allow the carbon fiber material to combine with the polyetheretherketone and solidify to obtain a first solidified product;

[0030] c) contacting the first solidified product with an aerosol containing polyetheretherketone, and curing the aerosol at a high temperature to obtain a second solidified product;

[0031] d) subjecting the second solidified product to molding.

[0032] In this specification, "carbon fiber material" refers to an aggregate of reinforcing carbon fibers. Before it is pre-impregnated and formed, it takes the form of strands. After forming and impregnation (particularly impregnation to a core), it has the form of a tape, strip or layer.

[0033] The main component in the carbon fiber material is carbon fiber, and the content of carbon fiber accounts for at least 70w / w%, or 80w / w%, or 90w / w%, or 95w / w%, or 99w / w% or higher of the mass of the carbon fiber material. Other fiber materials, such as mineral fiber, organic fiber or plant fiber, can be doped therein as needed. For example, mineral fiber includes glass fiber, basalt fiber, silicon oxide fiber, or silicon carbide fiber. For example, organic fiber includes fiber based on thermoplastic or thermosetting polymer, such as semi-aromatic polyamide fiber, aramid fiber or polyolefin fiber. Plant fiber includes natural flax fiber, hemp fiber, lignin fiber, bamboo fiber, silk fiber, especially spider silk fiber, sisal fiber and other cellulose fibers, especially viscose fiber. In order to promote the adhesion and impregnation of thermoplastic polymer matrix, these plant fibers can be used in pure, treated or coated form.

[0034] The carbon fiber material may also contain carbon-based fillers, in particular carbon black or carbon-based nanofillers, preferably selected from carbon nanofillers, in particular graphene and / or carbon nanotubes and / or carbon nanofibrils or blends thereof. These fillers enable the conduction of electricity and heat and therefore allow improved lubrication of the polymer matrix when it is heated.

[0035] In addition, as is well known to those skilled in the art, the carbon fiber reinforced polyetheretherketone composite material may contain at least one additive, which may be selected from catalysts, antioxidants, heat stabilizers, UV stabilizers, light stabilizers, lubricants, fillers, plasticizers, flame retardants, nucleating agents, chain extenders and dyes or mixtures thereof.

[0036] In some embodiments, the concentration of polyetheretherketone in the suspension of polyetheretherketone is 10m / v% to 18m / v%, such as 11m / v%, 12m / v%, 13m / v%, 14m / v%, 15m / v%, 16m / v%, 17m / v%. The solvent of the suspension of polyetheretherketone can be an inorganic or organic liquid, such as water, low or high molecular weight alcohol (such as ethanol, methanol, isopropanol), ketone (acetone, etc.), which will act as a non-permanent sizing agent; that is, it will exist in contact with the fiber for a short period of time, thereby allowing the fiber to be manipulated in a "dry" state (i.e., before pre-impregnation), and then it will be removed from the composite material to avoid destroying the final properties of the composite material.

[0037] In some preferred embodiments, the polyetheretherketone suspension further comprises a thickener and / or a dispersant.

[0038] In some embodiments, the thickener is selected from at least one of sodium carboxymethyl cellulose, hydroxypropyl methyl cellulose ether, xanthan gum, and modified polyurethane.

[0039] In some embodiments, the dispersant is selected from at least one of polyoxyethylene fatty acid esters, acrylates, styrene maleic anhydride polymers, and modified polyethers.

[0040] In some embodiments, the drying and melting is carried out in a heating process, and the starting temperature and the end temperature are within the following temperature range: 300°C to 470°C. Preferably, the drying and melting is carried out in stages, for example, 2, 3, 4, 5 or more stages at different temperatures. In some specific embodiments, the drying and melting is carried out in three stages, the temperature of the first stage is 300°C to 380°C, the temperature of the second stage is 320°C to 420°C, and the temperature of the third stage is 350°C to 470°C, and the temperature of the latter stage is higher than that of the former stage.

[0041] In some embodiments, step c) is performed at the residual temperature of step b). For example, for the above three-stage drying and melting, the residual temperature is 350° C. to 470° C. Preferably, step c) is performed immediately after step b).

[0042] In some embodiments, step c) is performed in a fluidized bed.

[0043] In some embodiments, the polyetheretherketone-containing aerosol comprises polyetheretherketone particles and polyvinyl alcohol particles.

[0044] In some embodiments, the mass ratio of the polyetheretherketone particles to the polyvinyl alcohol particles is (75-95):(5-15); for example, (78-92):(8-12); for example, 90:10.

[0045] In some embodiments, the average diameter D50 of the polyetheretherketone particles is 10 μm to 50 μm, for example, 20 μm, 30 μm, or 40 μm.

[0046] In some embodiments, the average diameter of the polyvinyl alcohol particles is D50=D50=5 μm to 15 μm; for example, 8 μm, 10 μm, or 12 μm.

[0047] In some embodiments, the molding method is selected from any one of compression molding, double-mold molding, winding molding, and vacuum bag molding.

[0048] In some embodiments, the preheating temperature for molding is 380°C to 440°C, for example, 390°C, 400°C, 410°C, 420°C, or 430°C.

[0049] In some embodiments, the carbon fiber reinforced polyetheretherketone composite material is a unidirectional tape.

[0050] A second aspect of the present disclosure relates to a carbon fiber reinforced polyetheretherketone composite material prepared by the method described above.

[0051] A third aspect of the present disclosure relates to the use of the carbon fiber reinforced polyetheretherketone composite material as described above in the manufacture of a three-dimensional component.

[0052] Advantageously, the three-dimensional component relates to the following fields: transport, in particular motor vehicles; oil and gas, in particular offshore; gas storage; civil or military aviation, aerospace, navigation, railways; renewable energy, in particular wind energy, tidal energy; energy storage devices; solar panels; thermal protection panels; sports and leisure; health and medical care; security and electronics.

[0053] The embodiments of the present disclosure will be described in detail below in conjunction with examples. It should be understood that these examples are only used to illustrate the present disclosure and are not intended to limit the scope of the present disclosure. The experimental methods for which specific conditions are not specified in the following examples are preferably referred to the guidance given in the present disclosure, and can also be based on the experimental manuals or conventional conditions in the art, and can also be based on other experimental methods known in the art, or according to the conditions recommended by the manufacturer.

[0054] In the following specific embodiments, the measured parameters of raw material components may have slight deviations within the range of weighing accuracy unless otherwise specified. For temperature and time parameters, acceptable deviations caused by instrument test accuracy or operation accuracy are allowed.

[0055] In the following examples and comparative examples, each component is added in parts by weight.

[0056] The carbon fibers used in the following examples and comparative examples are all domestically produced T700-12K grade carbon fibers.

[0057] Example 1

[0058] (1) Preparation of resin suspension: 2 parts of polyoxyethylene fatty acid ester was dissolved in 100 parts of distilled water, 20 parts of PEEK resin were added in portions, mixed well, 0.5 parts of sodium carboxymethyl cellulose was added, and stirred at 300 r / min for 120 min to obtain a resin suspension with a concentration of 16.7%.

[0059] (2) Carbon fiber spreading and desizing: The carbon fiber passes through 5 sets of vibrating spreading rollers to eliminate the overlap or twisting of the carbon fiber. The carbon fiber is desizing at a pulling speed of 2m / min and passed through an incinerator at 500℃. It then passes through 5 sets of mechanical spreading rollers to make the carbon fiber evenly arranged.

[0060] (3) Suspension impregnation: Dilute the 16.7% PEEK resin to 12.5% ​​with distilled water, and use a circulation pump to add the PEEK resin into the slurry tank. The carbon fiber passes through 5 rotatable dipping rollers in the slurry tank to complete the impregnation. Every 30 minutes, add 6 kg of 14% PEEK resin.

[0061] (4) Drying and melting: The drying and melting furnace is divided into three sections, with the drying section temperature at 380°C, the pre-melting section temperature at 400°C, and the melting section temperature at 450°C. The three sections have the same length. After passing through the drying and melting furnace, the carbon fiber is combined with the PEEK resin and solidified into a unidirectional tape.

[0062] (5) Fluidized bed impregnation: The carbon fiber passes through an aerosol fluidized bed, and under the action of the residual temperature of the unidirectional tape, PEEK resin (100% PEEK resin particles, D50 = 15 μm) is adsorbed on the surface. The fluidized bed air inlet speed is 2 m / s, and the atomizing gas pressure is 0.4 MPa.

[0063] (6) Molding preheating: The unidirectional tape is softened by a 410°C molding preheating device, which consists of an upper mold and a lower mold. The upper and lower molds are fixed at a certain angle. When the unidirectional tape passes through the mold, it gradually approaches the upper and lower molds until they are completely fitted together, which eventually softens the resin.

[0064] (7) Roller shaping: The unidirectional tape is preheated and then compacted and shaped by a low-temperature mirror roller before it is completely cooled. This increases the surface smoothness of the unidirectional tape, reduces the internal porosity, and improves the crystallinity of the resin.

[0065] (8) Cooling and winding: After low-temperature rolling and shaping, it is wound and wound through a collecting device with a winding torque of 8% and a torque coefficient of 0.5 to obtain a carbon fiber reinforced PEEK unidirectional tape product.

[0066] Example 2

[0067] (1) Preparation of resin suspension: 1 part of acrylate was dissolved in 100 parts of distilled water, 20 parts of PEEK resin were added in portions, mixed well, 0.3 parts of hydroxypropyl methylcellulose ether was added, and stirred at 300 r / min for 120 min to obtain a resin suspension with a concentration of 16.7%.

[0068] (2) Carbon fiber spreading and desizing: The carbon fiber passes through 5 sets of vibrating spreading rollers to eliminate overlapping or twisting of the carbon fiber. The carbon fiber is desizing at a pulling speed of 1.5m / min and passed through a 400℃ incinerator. It then passes through 5 sets of mechanical spreading rollers to make the carbon fiber evenly arranged.

[0069] (3) Suspension impregnation: Dilute the 16.7% PEEK resin to 12.5% ​​with distilled water, and use a circulation pump to add the PEEK resin into the slurry tank. The carbon fiber passes through 5 rotatable dipping rollers in the slurry tank to complete the impregnation. Every 30 minutes, add 6 kg of 14% PEEK resin.

[0070] (4) Drying and melting: The drying and melting furnace is divided into three sections. The drying section temperature is 350°C, the pre-melting section temperature is 380°C, and the melting section temperature is 430°C. The three sections are of the same length. After passing through the drying and melting furnace, the carbon fiber is combined with the PEEK resin and solidified into a unidirectional tape.

[0071] (5) Fluidized bed impregnation: The carbon fiber passes through an aerosol fluidized bed, and under the action of the residual temperature of the unidirectional tape, PEEK resin (100% PEEK resin particles, D50 = 15 μm) is adsorbed on the surface. The fluidized bed air inlet velocity is 0.5 m / s, and the atomizing gas pressure is 0.2 MPa.

[0072] (6) Molding preheating: The unidirectional tape is softened by a 410°C molding preheating device, which consists of an upper mold and a lower mold. The upper and lower molds are fixed at a certain angle. When the unidirectional tape passes through the mold, it gradually approaches the upper and lower molds until they are completely fitted together, which eventually softens the resin.

[0073] (7) Roller shaping: The unidirectional tape is preheated and then compacted and shaped by a low-temperature mirror roller before it is completely cooled. This increases the surface smoothness of the unidirectional tape, reduces the internal porosity, and improves the crystallinity of the resin.

[0074] (8) Cooling and winding: After low-temperature rolling and shaping, it is wound and wound through a collecting device with a winding torque of 8% and a torque coefficient of 0.5 to obtain a carbon fiber reinforced PEEK unidirectional tape product.

[0075] Example 3

[0076] (1) Preparation of resin suspension: 0.2 parts of styrene maleic anhydride polymer was dissolved in 100 parts of distilled water, 20 parts of PEEK resin were added in portions, mixed well, 0.5 parts of xanthan gum was added, and stirred at 300 r / min for 120 minutes to obtain a resin suspension with a concentration of 16.7%.

[0077] (2) Carbon fiber spreading and desizing: The carbon fiber passes through 5 sets of vibrating spreading rollers to eliminate the overlap or twisting of the carbon fiber. The carbon fiber is desizing at a pulling speed of 1m / min and passed through an incinerator at 450℃. It then passes through 5 sets of mechanical spreading rollers to make the carbon fiber evenly arranged.

[0078] (3) Suspension impregnation: Dilute the 16.7% PEEK resin to 12.5% ​​with distilled water, and use a circulation pump to add the PEEK resin into the slurry tank. The carbon fiber passes through 5 rotatable dipping rollers in the slurry tank to complete the impregnation. Every 30 minutes, add 6 kg of 14% PEEK resin.

[0079] (4) Drying and melting: The drying and melting furnace is divided into three sections. The drying section temperature is 330°C, the pre-melting section temperature is 350°C, and the melting section temperature is 400°C. The three sections are of the same length. After passing through the drying and melting furnace, the carbon fiber is combined with the PEEK resin and solidified into a unidirectional tape.

[0080] (5) Fluidized bed impregnation: The carbon fiber passes through an aerosol fluidized bed, and under the action of the residual temperature of the unidirectional tape, PEEK resin (100% PEEK resin particles, D50 = 15 μm) is adsorbed on the surface. The fluidized bed air inlet velocity is 0.4 m / s, and the atomizing gas pressure is 0.1 MPa.

[0081] (6) Molding preheating: The unidirectional tape is softened by a 410°C molding preheating device, which consists of an upper mold and a lower mold. The upper and lower molds are fixed at a certain angle. When the unidirectional tape passes through the mold, it gradually approaches the upper and lower molds until they are completely fitted together, which eventually softens the resin.

[0082] (7) Roller shaping: The unidirectional tape is preheated and then compacted and shaped by a low-temperature mirror roller before it is completely cooled. This increases the surface smoothness of the unidirectional tape, reduces the internal porosity, and improves the crystallinity of the resin.

[0083] (8) Cooling and winding: After low-temperature rolling and shaping, it is wound and wound through a collecting device with a winding torque of 8% and a torque coefficient of 0.5 to obtain a carbon fiber reinforced PEEK unidirectional tape product.

[0084] Example 4

[0085] (1) Preparation of resin suspension: 0.5 parts of modified polyether was dissolved in 100 parts of distilled water, 20 parts of PEEK resin were added in portions, mixed well, 0.1 parts of modified polyurethane was added, and stirred at 300 r / min for 120 min to obtain a resin suspension with a concentration of 16.7%.

[0086] (2) Carbon fiber spreading and desizing: The carbon fiber passes through 5 sets of vibrating spreading rollers to eliminate the overlap or twisting of the carbon fiber. The carbon fiber is desizing at a pulling speed of 1m / min and passed through an incinerator at 500℃. It then passes through 5 sets of mechanical spreading rollers to make the carbon fiber evenly arranged.

[0087] (3) Suspension impregnation: Dilute the 16.7% PEEK resin to 12.5% ​​with distilled water, and use a circulation pump to add the PEEK resin into the slurry tank. The carbon fiber passes through 5 rotatable dipping rollers in the slurry tank to complete the impregnation. Every 30 minutes, add 6 kg of 14% PEEK resin.

[0088] (4) Drying and melting: The drying and melting furnace is divided into three sections. The temperature of the drying section is 320°C, the temperature of the pre-melting section is 330°C, and the temperature of the melting section is 360°C. The three sections are of the same length. After passing through the drying and melting furnace, the carbon fiber is combined with the PEEK resin and solidified into a unidirectional tape.

[0089] (5) Fluidized bed impregnation: The carbon fiber passes through an aerosol fluidized bed, and under the action of the residual temperature of the unidirectional tape, PEEK resin (100% PEEK resin particles, D50 = 15 μm) is adsorbed on the surface. The fluidized bed air inlet velocity is 0.2 m / s, and the atomizing gas pressure is 0.1 MPa.

[0090] (6) Molding preheating: The unidirectional tape is softened by a 410°C molding preheating device, which consists of an upper mold and a lower mold. The upper and lower molds are fixed at a certain angle. When the unidirectional tape passes through the mold, it gradually approaches the upper and lower molds until they are completely fitted together, which eventually softens the resin.

[0091] (7) Roller shaping: The unidirectional tape is preheated and then compacted and shaped by a low-temperature mirror roller before it is completely cooled. This increases the surface smoothness of the unidirectional tape, reduces the internal porosity, and improves the crystallinity of the resin.

[0092] (8) Cooling and winding: After low-temperature rolling and shaping, it is wound and wound through a collecting device with a winding torque of 8% and a torque coefficient of 0.5 to obtain a carbon fiber reinforced PEEK unidirectional tape product.

[0093] Example 5

[0094] The same as Example 4, except that step (5) uses a mixture of 90 w / w% PEEK resin particles (D50=15 μm) and 10 w / w% PVA particles (D50=10 μm).

[0095] Comparative Example 1

[0096] The same as Example 4, the only difference is that step (5) of the original fluidized bed impregnation step is eliminated.

[0097] Comparative Example 2

[0098] The same as Example 4, except that the original fluidized bed impregnation step in step (5) is replaced by:

[0099] (5) Applying PEEK film: PEEK resin film with a thickness of 50 μm is applied to the upper and lower surfaces of the dried and melted unidirectional tape, and is melted in a high-temperature oven.

[0100] Comparative Example 3

[0101] The same as Example 4, except that the original fluidized bed impregnation step in step (5) is replaced by:

[0102] (5) Suspension impregnation: the unidirectional tape is passed through a PEEK resin slurry tank with a concentration of 12.5% ​​again to complete the secondary impregnation.

[0103] Comparative Example 4

[0104] Same as Example 5, except that the PVA particles are replaced with polylactic acid particles of the same particle size.

[0105] The performance summary results of the embodiments / comparative examples are shown in the following table:

[0106]

[0107] in:

[0108] Resin content is tested according to HB 7736.5;

[0109] Tensile strength is tested according to ASTM D 3039;

[0110] The interlayer short beam shear strength is tested according to ASTM D 2344;

[0111] The post-impact compressive strength is tested according to ASTM D 7136 and ASTM D 7137.

[0112] Examples 1 to 4 all use an aerosol fluidized bed impregnation process to increase the resin content on the surface of the unidirectional tape. By controlling different process conditions, the resin content in Example 4 is increased less, and the tensile strength, short beam shear strength and post-impact compression strength of the prepreg are all maintained at a high level.

[0113] Example 5 improves the air flow atomization fluidized bed process on the basis of Example 4, using PEEK particles and mixing some PVA particles. From the results, compared with Example 4, under the premise that the tensile strength is not significantly damaged, the interlayer short beam shear strength and the post-impact compression strength are further improved. In view of the fact that the strength of PVA is lower than that of PEEK, but its melting point is lower, and the amount of PVA added is not high, it is speculated that the reason why it works is mainly because it can assist the adsorption of PEEK and help it enter the gaps in the material, making the surface smoother.

[0114] Comparative Example 1 is a conventional powder wet unidirectional tape preparation process. Due to the low resin content and rough surface of the unidirectional tape (refer to Figure 1 ), resulting in poor interlaminar interface strength, poor short beam shear strength and post-impact compressive strength of the unidirectional tape.

[0115] Comparative Example 2 increases the resin content on the surface of the unidirectional tape by applying a PEEK film. Since the moldability of PEEK resin is poor, the minimum thickness of the film is about 20um. After being applied to the unidirectional tape, the overall resin content reaches 45%, resulting in a significant reduction in tensile properties.

[0116] Comparative Example 3 adopts the process of secondary suspension dipping to prepare the unidirectional tape. After the unidirectional tape is melted and solidified, it has a relatively high hardness. During the secondary suspension dipping process, it causes multiple cracks under the action of tension, resulting in a decrease in performance.

[0117] In comparative example 4, polylactic acid particles are used to replace PVA particles. Although polylactic acid has a lower melting point and theoretically should have a better effect, the actual performance is not ideal. It is speculated that the lower the melting point of the auxiliary particles, the better, and it is also related to factors such as the viscosity / strength / affinity of the particles themselves and carbon fiber.

[0118] In summary, according to the embodiments of the present disclosure, in a preferred embodiment, after the unidirectional tape is dried and melted, the PEEK resin is atomized by an airflow atomization fluidized bed, so that the unidirectional tape is atomized PEEK resin. Under the action of the residual temperature of the unidirectional tape, the resin powder is uniformly adsorbed on its surface. After preheating and shaping, a layer of resin film is formed on the surface of the unidirectional tape. During the lamination molding process, the surface resin layer can significantly improve the interlayer interface strength after melting, and improve the interlayer shear strength and post-impact compression strength without basically affecting the tensile strength. At the same time, doping a small amount of PVA in the atomization process can further improve the performance. The preparation method has a simple process and low production cost. It not only retains the advantages of low fiber damage and good impregnation effect of the wet process, but also the surface resin layer can fill the internal pores of the unidirectional tape caused by the evaporation of water in the drying and melting process in the wet process. By changing the air flow rate and internal pressure of the fluidized bed to adjust the concentration of the atomized PEEK resin powder, the thickness of the surface resin layer can be accurately controlled.

[0119] The above-described embodiments only express several implementation methods of the present disclosure, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present disclosure, and these all belong to the protection scope of the present disclosure. Therefore, the protection scope of the patent of the present disclosure shall be based on the attached claims, and the description and drawings may be used to interpret the contents of the claims.

Claims

1. A method for preparing a carbon fiber reinforced polyetheretherketone composite material, comprising: a) providing a carbon fiber material having a plurality of parallel strands made of continuous carbon fibers and impregnating the carbon fiber material in a suspension of polyetheretherketone; b) drying the melt to allow the carbon fiber material to combine with the polyetheretherketone and solidify to obtain a first solidified product; c) contacting the first solidified product with an aerosol containing polyetheretherketone, and curing the aerosol at a high temperature to obtain a second solidified product; d) subjecting the second solidified product to molding.

2. The method according to claim 1, wherein the concentration of polyetheretherketone in the polyetheretherketone suspension is 10 m / v% to 18 m / v%.

3. The method according to claim 1 or 2, wherein the polyetheretherketone suspension further comprises a thickener and / or a dispersant; The preferred thickener is at least one selected from sodium carboxymethyl cellulose, hydroxypropyl methyl cellulose ether, xanthan gum, and modified polyurethane; The preferred dispersant is at least one selected from polyoxyethylene fatty acid esters, acrylic esters, styrene maleic anhydride polymers, and modified polyethers.

4. The method according to claim 1, wherein the drying and melting is carried out at an elevated temperature, and the starting temperature and the end temperature are within the following temperature range: 300°C to 470°C.

5. The method according to claim 1, 2 or 4, wherein step c) is carried out at the residual temperature of step b); preferably step c) is carried out in a fluidized bed.

6. The method according to claim 1, 2 or 4, wherein the polyetheretherketone-containing aerosol comprises polyetheretherketone particles and polyvinyl alcohol particles; preferably, the mass ratio of the polyetheretherketone particles to the polyvinyl alcohol particles is (75-95):(5-15); Preferably, the average diameter D50 of the polyetheretherketone particles is 10 μm to 50 μm; Preferably, the average diameter D50 of the polyvinyl alcohol particles is 5 μm to 15 μm.

7. The method according to claim 1, 2 or 4, wherein the molding method is selected from any one of compression molding, double-mold molding, winding molding, and vacuum bag molding, and the preferred preheating temperature for molding is 380°C to 440°C.

8. The method according to claim 1, 2 or 4, wherein the carbon fiber reinforced polyetheretherketone composite material is a unidirectional tape.

9. A carbon fiber reinforced polyetheretherketone composite material prepared by the method according to any one of claims 1 to 8.

10. Use of the carbon fiber reinforced polyetheretherketone composite material according to claim 8 in manufacturing three-dimensional parts.

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