Polyaryletherketone prepreg and preparation method thereof

Abstract

The invention relates to the technical field of carbon fiber prepreg cloth, in particular to polyaryletherketone prepreg cloth and a preparation method thereof.Firstly, core-shell structure acrylate emulsion is synthesized to serve as a dispersing agent of polyaryletherketone resin powder to be prepared into sizing liquid, the sizing liquid is adopted for conducting surface treatment on carbon fiber fabric, and then the surface of the carbon fiber fabric is coated with the polyaryletherketone prepreg cloth. Then drying and pressing to obtain polyaryletherketone prepreg cloth; according to the preparation method, stable dispersion of the polyaryletherketone resin powder in the emulsion can be realized, effective infiltration of the carbon fibers is realized, and the interface strength and the overall mechanical property of the composite material are remarkably improved.

Description

Technical Field

[0001] The present invention relates to the technical field of carbon fiber prepregs, and particularly relates to a polyaryletherketone prepreg and a preparation method thereof. Background Art

[0002] Polyaryletherketone is a high-performance special engineering plastic, having excellent properties such as high temperature resistance, chemical corrosion resistance, wear resistance, high strength, high toughness, and good electrical insulation. It has a wide range of applications in high-tech fields such as aerospace, automotive industry, biomedical, and electronic and electrical. As an important intermediate of composite materials, prepregs combine polyaryletherketone with fiber reinforcement materials (such as carbon fiber, glass fiber, etc.), and can give full play to the advantages of both to prepare high-performance composite materials.

[0003] Carbon fiber prepreg is a carbon fiber composite material processed through processes such as coating film, hot pressing, cooling, film covering, and winding after the carbon fiber is fully infiltrated with a resin matrix, also known as carbon fiber prepreg. By chemically or physically treating the surface of carbon fiber to form sizing modification of carbon fiber, it aims to improve its bonding performance with matrix materials (such as resin or rubber) and the overall performance of composite materials. Due to the inert surface chemical properties of traditional carbon fibers, the interfacial bonding with matrix materials is weak, affecting mechanical properties and durability. Therefore, the modification treatment has become a key step in optimizing carbon fiber sizing. Common modification methods include chemical oxidation, electrochemical oxidation, and coating. The chemical oxidation method treats carbon fiber with acidic or alkaline solutions such as concentrated acids or concentrated alkalis to generate surface oxides (such as carboxylic acids, phenolic hydroxyls), enhancing the affinity with sizing; electrochemical oxidation generates oxygen-containing functional groups on the surface of carbon fiber under the action of an electric field to improve activity; the coating method covers the fiber surface with nanomaterials or functional polymers to further enhance interfacial bonding.

[0004] Conventional carbon fibers have an epoxy resin sizing agent on their surface, and this sizing agent has poor interfacial bonding effect with resin and poor wetting effect on carbon fibers. In addition, Patent No. CN 116855078 A discloses a slurry for carbon fiber prepreg, a preparation method thereof, and a preparation method of prepreg. This patent reduces the surface energy of the dispersion medium water of the slurry by adding a surfactant, but the dispersion stability of resin powder in it is still poor, the resin powder is prone to agglomeration problems, and continuous stirring is required to reduce the risk of sedimentation. Summary of the Invention

[0005] In order to solve the above technical problems, the present invention provides a polyaryletherketone prepreg and a preparation method thereof. By using the synthesized core-shell structured acrylate emulsion as a dispersant for polyaryletherketone resin powder, the present invention can achieve stable dispersion of polyaryletherketone resin powder in the emulsion and effectively infiltrate carbon fibers.

[0006] To achieve the above object, the present invention is realized through the following technical solutions:

[0007] A preparation method of a polyaryletherketone prepreg, which is prepared by surface-treating a carbon fiber fabric with a sizing agent and then drying and pressing;

[0008] The sizing agent contains the following materials in 100% by mass: 0.3%-1% of core-shell structured acrylate emulsion, 15%-35% of polyaryletherketone resin powder, 8%-15% of absolute ethanol, and the balance is water;

[0009] Among them, the core layer material is a copolymer formed by the following core layer monomers: (meth)acrylic acid, butyl (meth)acrylate and 2-hydroxyethyl (meth)acrylate; the shell layer material is a copolymer formed by the following shell layer monomers: (meth)acrylic acid and butyl (meth)acrylate, N-(hydroxymethyl)(meth)acrylamide, and one or more of 2-hydroxyethyl (meth)acrylate.

[0010] Furthermore, in the core layer monomers, (meth)acrylic acid, butyl (meth)acrylate and 2-hydroxyethyl (meth)acrylate are configured in a mass ratio of 15-50:20-30:2-5;

[0011] The combination of the shell layer monomers is (meth)acrylic acid, butyl (meth)acrylate and N-(hydroxymethyl)(meth)acrylamide configured in a mass ratio of 10:2:0.5, or (meth)acrylic acid and N-(hydroxymethyl)(meth)acrylamide, butyl (meth)acrylate, and one of 2-hydroxyethyl (meth)acrylate configured in a mass ratio of 10-15:1-3;

[0012] Based on the total mass of the shell layer monomers and the core layer monomers, the mass percentage ratio of the core layer monomers to the shell layer monomers is 70%-85%:15%-30%.

[0013] Furthermore, the polymerization process of the core-shell structured acrylate emulsion includes the following material configurations:

[0014] The raw material liquid, based on the total mass of the shell layer monomers and the core layer monomers, the raw material liquid includes 0.1%-0.5% of initiator, 0.12%-0.25% of pH regulator, 0.12%-0.22% of emulsifier, and 90%-150% of water;

[0015] The shell layer reaction liquid, based on the total mass of the shell layer monomers and the core layer monomers, the shell layer reaction liquid contains 15%-30% of shell layer monomers and 0.25%-0.8% of emulsifier;

[0016] The core layer reaction liquid, based on the total mass of the shell layer monomers and the core layer monomers, the core layer reaction liquid contains 70%-85% of core layer monomers and 1.3%-2.5% of emulsifier.

[0017] Furthermore, the polymerization process of the core-shell structured acrylate emulsion comprises the following steps:

[0018] Prepare an initiator aqueous solution, a pH regulator aqueous solution and an emulsifier aqueous solution respectively according to the ratio requirements;

[0019] Add a part of the emulsifier aqueous solution to the pH regulator aqueous solution. Under continuous stirring, add a part of the core layer reaction solution and heat up to 75-80 °C. Add a part of the initiator aqueous solution. After the system turns blue, continue the reaction for 5-15 min. Dropwise add the remaining part of the core layer reaction solution and a part of the initiator aqueous solution within 1.5-2.5 h. After the dropping is completed, continue the reaction for 50-80 min. Then dropwise add the shell layer reaction solution and the remaining part of the initiator aqueous solution. After the dropping is completed, continue the reaction for 20-40 min. Heat up to 80-90 °C and continue the reaction for 50-80 min. Then cool down and adjust the pH value to 7-8 to obtain the core-shell structured acrylate emulsion; the solid content of the core-shell structured acrylate emulsion is at least 35 wt%.

[0020] Furthermore, the pH regulator is sodium bicarbonate; the emulsifier is selected from one or more of sodium dodecyl sulfate, sodium stearate and sodium hexadecyl sulfonate; the initiator is selected from potassium persulfate and / or ammonium persulfate.

[0021] Furthermore, the polyaryletherketone powder is selected from one or more of polyetheretherketone (PEEK), polyetherketone (PEK), and polyetherketoneetherketone (PEKEK). Under the test conditions of 400 °C and 2.16 kg, the melt index of the polyaryletherketone powder > 15 g / 10 min, and the particle size in the powder does not exceed 50 μm.

[0022] Furthermore, the feeding order in the preparation process of the sizing agent is: add absolute ethanol to the core-shell structured acrylate emulsion and stir for 10-20 min. Add the polyaryletherketone resin powder. After dispersing evenly, add water to adjust the concentration and continuously stir for 15-30 min.

[0023] Furthermore, the surface treatment is spraying or dipping, and the surface treatment time is controlled according to the sizing amount; before the surface treatment, the carbon fiber fabric needs to be desized, and either chemical solvent desizing or direct high-temperature physical desizing can be used; the pressing temperature is 380-420 °C and the pressing time is 30-60 seconds.

[0024] On the other hand, the present invention provides a polyaryletherketone prepreg obtained by the above preparation method. In the polyaryletherketone prepreg, calculated by 100% mass percentage: the core-shell structured acrylate accounts for 0.3 wt%-2.0 wt%, the polyaryletherketone resin accounts for 40 wt%-60 wt%, and the balance is the carbon fiber fabric.

[0025] Beneficial technical effects:

[0026] 1. Fiber surface modification to enhance interfacial bonding

[0027] By modifying the carbon fiber surface with acrylic emulsion, the interfacial compatibility between the carbon fiber and the polyaryletherketone resin can be significantly improved. The polar groups in the acrylic emulsion (such as methacrylic acid, butyl acrylate, etc.) can chemically adsorb or physically anchor to the carbon fiber surface, thereby forming a uniform modified layer on the fiber surface. This modified layer can effectively enhance the adhesion between the fiber and the resin, allowing stress to be transferred more efficiently between the two, thereby significantly improving the interfacial strength and overall mechanical properties of the composite material.

[0028] 2. Optimize the sizing liquid formula to improve wettability

[0029] The sizing solution contains a variety of polar acrylate monomers (such as methacrylic acid, butyl acrylate, N-hydroxymethyl acrylamide, etc.), which are polymerized by emulsion to form an emulsion with excellent wettability. This emulsion can be quickly and evenly coated on the surface of the carbon fiber to ensure that the polyaryletherketone resin powder can fully wet the fiber. This optimized sizing solution formula not only improves the wettability of the fiber, but also reduces defects and voids on the fiber surface, further improving the quality and performance of the composite material. The addition of anhydrous ethanol reduces the surface tension of the sizing solution, reduces the generation of bubbles, and avoids uneven dispersion caused by bubbles.

[0030] 3. High temperature treatment of fibers to improve surface activity

[0031] During the preparation process, the carbon fiber cloth is first treated with high temperature (380℃-420℃), which can remove the original epoxy sizing agent on the fiber surface and produce micropores and active sites on the fiber surface. These micropores and active sites provide more binding points for the subsequent impregnation of acrylic emulsion and polyaryletherketone resin, significantly improving the surface activity of the fiber and its binding force with the resin. This high temperature treatment process is an important part of fiber modification and lays the foundation for the subsequent impregnation and curing process.

[0032] 4. Improve the adhesion and durability of sizing liquid

[0033] The dispersibility of inorganic fillers and polymer powders is improved by hydrogen bonding in acrylic emulsions. At the same time, the polar groups in acrylic emulsions can form strong chemical bonds with the carbon fiber surface, improving the adhesion and durability of polyaryletherketone powder in the sizing solution. This makes the polyaryletherketone powder less likely to fall off after the subsequent drying process of the carbon fiber cloth, maintaining good adhesion and ensuring the resin content of the prepreg cloth.

[0034] 5. Advanced technology

[0035] The sizing agent solution is sprayed onto the carbon fiber surface through atomization technology to evenly disperse the sizing agent, ensuring sufficient contact between the resin powder and the fibers, and reducing local uneven wetting or dry yarn phenomena. At the same time, the spraying method can accurately control the spraying time and the amount of sizing agent used, which is applicable to carbon fiber fabrics with different thicknesses and weaving structures (such as twill, plain, satin), and can meet the processing requirements of complex shapes. Description of the Drawings

[0036] Figure 1 Photographs of the dispersion of the sizing agents prepared in Examples 1-2 and Comparative Examples 1-3;

[0037] Figure 2 SEM images of the polyaryletherketone prepregs prepared in Example 1 and Comparative Example 2. Detailed Description of the Invention

[0038] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. The description of at least one exemplary embodiment is actually only illustrative and in no way limits the present invention and its application or use. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention.

[0039] Unless otherwise specifically stated, the numerical values set forth in these embodiments do not limit the scope of the present invention. Technologies and methods known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, such technologies and methods should be regarded as part of the specification. In all examples shown and discussed herein, any specific value should be construed as merely exemplary and not as a limitation. Therefore, other examples of the exemplary embodiments may have different values.

[0040] In the following examples, the experimental methods without specific conditions are generally determined according to national standards; if there is no corresponding national standard, they are carried out according to general standard requirements or general methods.

[0041] It should be noted that the notation such as (meth)acrylic acid means acrylic acid or methacrylic acid, and so on.

[0042] Preparation Example 1

[0043] The preparation process of the core-shell structured acrylate emulsion is as follows:

[0044] Prepare the initiator aqueous solution: Dissolve 0.2 g of potassium persulfate and 0.3 g of ammonium persulfate in 15 g of ultrapure water to form the initiator aqueous solution;

[0045] Prepare the emulsifier aqueous solution: Dissolve 1.2 g of sodium dodecyl sulfate in 62 g of ultrapure water to form the emulsifier aqueous solution; take 12 g for preparing the shell reaction solution and 45 g for preparing the core reaction solution; the compositions of the shell reaction solution and the core reaction solution are shown in Table 1-1 as follows:

[0046] Table 1-1 Compositions of the shell reaction solution and the core reaction solution in Preparation Example 1

[0047] Core layer reaction solution Shell layer reaction solution Emulsifier aqueous solution 45 g Emulsifier aqueous solution 12 g Methacrylic acid 18 g Methacrylic acid 10 g Butyl acrylate 25 g Butyl acrylate 2 g 2-Hydroxyethyl acrylate 3 g N-Methylolacrylamide 0.5 g

[0048] According to the above formula, mechanically stir the monomer and the emulsifier aqueous solution at room temperature for 15 min for pre-emulsification to obtain the core reaction solution and the shell reaction solution respectively;

[0049] Add 0.12 g of sodium bicarbonate and 10 g of ultrapure water into a 250 mL four-necked flask, stir and dissolve evenly to obtain the pH regulator aqueous solution; take 5 g of the remaining emulsifier aqueous solution and add it to the pH regulator aqueous solution and stir evenly, take 12 g of the core reaction solution and pour it into the reaction flask, set the stirring speed to 200 r / min, heat up to 80 °C, add 3 g of the initiator aqueous solution, after the reaction solution turns blue, continue the reaction for 10 min; drip the remaining core reaction solution and 8 g of the initiator aqueous solution, complete the dripping in about 2 h, continue the reaction for 1 h; then drip the shell reaction solution and 2.5 g of the initiator aqueous solution, continue the reaction for 30 min after the dripping is completed, heat up to 85 °C and continue the reaction for 1 h, and cool down, adjust the pH = 7 - 8 with ammonia water. In this case, a core-shell structured acrylate emulsion with a solid content of 38.3 wt% is obtained.

[0050] Preparation Example 2

[0051] The preparation process of the core-shell structured acrylate emulsion is as follows:

[0052] Prepare the initiator aqueous solution: Dissolve 0.25 g of potassium persulfate and 0.25 g of ammonium persulfate in 15 g of ultrapure water to form the initiator aqueous solution;

[0053] Prepare the emulsifier aqueous solution: Dissolve 1.5 g of sodium dodecyl sulfate in 62 g of ultrapure water to form the emulsifier aqueous solution; take 17 g for preparing the shell reaction solution and 40 g for preparing the core reaction solution; the compositions of the shell reaction solution and the core reaction solution are shown in Table 1-2 as follows:

[0054] Table 1-2 Compositions of the shell reaction solution and the core reaction solution in Preparation Example 2

[0055] Core layer reaction solution Shell layer reaction solution Emulsifier aqueous solution 40 g Emulsifier aqueous solution 17 g Methacrylic acid 15 g Methacrylic acid 10 g Butyl acrylate 27 g Butyl acrylate 2 g 2-Hydroxyethyl acrylate 5 g N-Methylolacrylamide 0.5 g

[0056] The subsequent process is the same as that in Preparation Example 1. In this case, a core-shell structured acrylate emulsion with a solid content of 39.1 wt% is obtained.

[0057] Preparation Example 3

[0058] The preparation process of the core-shell structured acrylate emulsion is as follows:

[0059] Prepare the initiator aqueous solution: Dissolve 0.5 g of potassium persulfate in 15 g of ultrapure water to form the initiator aqueous solution;

[0060] Prepare the emulsifier aqueous solution: Dissolve 1.5 g of sodium dodecyl sulfate in 65 g of ultrapure water to form the emulsifier aqueous solution; Take 15 g for preparing the shell layer reaction solution and 45 g for preparing the core layer reaction solution; The compositions of the shell layer reaction solution and the core layer reaction solution are shown in Table 1-3 below:

[0061] Table 1-3 Compositions of the shell layer reaction solution and the core layer reaction solution in Preparation Example 3

[0062] Core layer reaction solution Shell layer reaction solution Emulsifier aqueous solution 45 g Emulsifier aqueous solution 15 g Methacrylic acid 24 g Methacrylic acid 11 g Butyl acrylate 22 g N-Methylolacrylamide 3 g 2-Hydroxyethyl acrylate 2 g /

[0063] The subsequent process is the same as that in Preparation Example 1, and a core-shell structured acrylate emulsion with a solid content of 38.2 wt% is obtained in this example.

[0064] Preparation Example 4

[0065] The preparation process of the core-shell structured acrylate emulsion is as follows:

[0066] Prepare the initiator aqueous solution: Dissolve 0.5 g of ammonium persulfate in 15 g of ultrapure water to form the initiator aqueous solution;

[0067] Prepare the emulsifier aqueous solution: Dissolve 1.8 g of sodium dodecyl sulfate in 65 g of ultrapure water to form the emulsifier aqueous solution; Take 10 g for preparing the shell layer reaction solution and 50 g for preparing the core layer reaction solution; The compositions of the shell layer reaction solution and the core layer reaction solution are shown in Table 1-4 below:

[0068] Table 1-4 Compositions of the shell layer reaction solution and the core layer reaction solution in Preparation Example 4

[0069] Core layer reaction solution Shell layer reaction solution Emulsifier aqueous solution 50 g Emulsifier aqueous solution 10 g Methacrylic acid 20 g Methacrylic acid 14.8 g Butyl acrylate 25 g Butyl acrylate 3 g 2-Hydroxyethyl acrylate 3.5 g /

[0070] The subsequent process is the same as that in Preparation Example 1, and a core-shell structured acrylate emulsion with a solid content of 37.9 wt% is obtained in this example.

[0071] Preparation Example 5

[0072] The preparation process of the core-shell structured acrylate emulsion is as follows:

[0073] Prepare the initiator aqueous solution: Dissolve 0.25 g of potassium persulfate and 0.25 g of ammonium persulfate in 15 g of ultrapure water to form the initiator aqueous solution;

[0074] Prepare the emulsifier aqueous solution: Dissolve 1.8 g of sodium dodecyl sulfate in 65 g of ultrapure water to form the emulsifier aqueous solution; Take 10 g for preparing the shell layer reaction solution and 50 g for preparing the core layer reaction solution; The compositions of the shell layer reaction solution and the core layer reaction solution are shown in Table 1-5 below:

[0075] Table 1-5 Composition of the shell reaction solution and the core reaction solution of Preparation Example 5

[0076] Core layer reaction solution Shell layer reaction solution Emulsifier aqueous solution 50 g Emulsifier aqueous solution 10 g Methacrylic acid 20 g Methacrylic acid 14.8 g Butyl acrylate 25 g / 2-Hydroxyethyl acrylate 3.5 g 2-Hydroxyethyl acrylate 3 g

[0077] The subsequent process is the same as that of Preparation Example 1, and a core-shell structured acrylate emulsion with a solid content of 38.1 wt% is obtained in this example.

[0078] Preparation Example 6

[0079] The preparation process of the core-shell structured acrylate emulsion is the same as that of Example 1, but partial non-polar acrylic monomers are selected: phenethyl acrylate, isoamyl acrylate, and octadecyl acrylate.

[0080] Prepare the initiator aqueous solution: Dissolve 0.2 g of potassium persulfate and 0.3 g of ammonium persulfate in 15 g of ultrapure water to form the initiator aqueous solution;

[0081] Prepare the emulsifier aqueous solution: Dissolve 1.2 g of sodium dodecyl sulfate in 62 g of ultrapure water to form the emulsifier aqueous solution; 12 g is taken for preparing the shell reaction solution, and 45 g is taken for preparing the core reaction solution; The compositions of the shell reaction solution and the core reaction solution are shown in Table 1-6 below:

[0082] Table 1-6 Composition of the shell reaction solution and the core reaction solution of Preparation Example 6

[0083] Core layer reaction solution Shell layer reaction solution Emulsifier aqueous solution 45 g Emulsifier aqueous solution 12 g Phenethyl acrylate 18 g Phenethyl acrylate 10 g Butyl acrylate 25 g Butyl acrylate 2 g Isoamyl acrylate 3 g Octadecyl acrylate 0.5 g

[0084] The subsequent process is the same as that of Preparation Example 1, and a core-shell structured acrylate emulsion with a solid content of 38.5 wt% is obtained in this example.

[0085] Example 1

[0086] A preparation method of a polyaryletherketone prepreg, which is prepared by surface-treating a carbon fiber cloth with a sizing agent and then drying and pressing it. The specific steps are as follows:

[0087] S1. Cut the woven satin carbon fiber cloth into 300 mm × 300 mm and place it in an oven. Heat it to 400 °C and keep it at a constant temperature for 5 h. During this period, open the oven for ventilation for 20 - 30 s every 1 h to remove the original epoxy sizing agent in the carbon fiber cloth;

[0088] S2. Place the carbon fiber cloth treated in S1 on a platform and use a sizing sprayer to spray the sizing agent for surface treatment for 15 s;

[0089] The sizing formulation is as follows: 2 g of a core-shell structured acrylate emulsion with a solid content of 38.3 wt%, 90 g of polyether ether ketone resin powder with a particle size of 15 μm (melt index of 32 g / 10 min under test conditions of 400 °C and 2.16 kg), 50 g of absolute ethanol, and 350 g of ultrapure water;

[0090] Sizing preparation method: Add the core-shell structured acrylate emulsion to absolute ethanol and stir for 10 min, then add the polyether ether ketone resin powder, add ultrapure water, and continue stirring for 20 min;

[0091] S3. Place the carbon fiber containing the sizing obtained in S2 in an oven at 120 °C and dry for 30 min to obtain an intermediate product;

[0092] S4. Attach a release film to each of the upper and lower surfaces of the intermediate product, place it in a flat vulcanizing machine at a temperature of 380 °C, press for 30 s and take out to obtain a polyaryletherketone prepreg.

[0093] For the polyaryletherketone prepreg prepared in this example, calculated by 100 wt%, the core-shell structured acrylate accounts for 0.45 wt%, the polyether ether ketone resin accounts for 50 wt%, and the balance is carbon fiber cloth.

[0094] The physical picture of the sizing configured in this example after standing for 15 minutes is as Figure 1 shown. It can be seen that the polyether ether ketone resin powder is well dispersed in the aqueous phase and there is no obvious sedimentation phenomenon.

[0095] The SEM image of the polyaryletherketone prepreg prepared in this example is as Figure 2 shown. The scale length in the figure is 20 μm. It can be seen that using the core-shell structured acrylate emulsion of the present invention as a dispersant for the polyether ether ketone resin powder can better disperse the resin and the sizing has a good pre-impregnation effect on the fibers, and there is no obvious dry yarn on the carbon fibers.

[0096] Example 2

[0097] The preparation method of the polyaryletherketone prepreg in this example is the same as the preparation process of Example 1, except that in S2, the sizing formulation is as follows:

[0098] The sizing formulation is as follows: 2.5 g of a core-shell structured acrylate emulsion with a solid content of 39.1 wt%, 85 g of polyether ether ketone resin powder with a particle size of 30 μm (melt index of 20 g / 10 min under test conditions of 400 °C and 2.16 kg), 45 g of absolute ethanol, and 320 g of ultrapure water.

[0099] For the polyaryletherketone prepreg prepared in this example, calculated by 100 wt%, the core-shell structured acrylate accounts for 0.59 wt%, the polyether ether ketone resin accounts for 52 wt%, and the balance is carbon fiber cloth.

[0100] The physical photo of the sizing agent solution in this case after being placed for 15 minutes is as Figure 1 shown. It can be seen that the polyetheretherketone resin powder is well dispersed in the aqueous phase and there is no obvious sedimentation phenomenon.

[0101] Example 3

[0102] The preparation method of the polyaryletherketone prepreg in this case is the same as that in Example 1. The difference is that the sizing agent solution formula in S2 is as follows:

[0103] The sizing agent solution formula is as follows: 2 g of core-shell structured acrylate emulsion with a solid content of 38.2 wt% prepared in Preparation Example 3, 90 g of polyetheretherketone resin powder with a particle size of 30 μm (the melt index under the test conditions of 400 °C and 2.16 kg is 20 g / 10 min), 45 g of absolute ethanol, and 350 g of ultrapure water.

[0104] For the polyaryletherketone prepreg prepared in this case, calculated by 100 wt%, the core-shell structured acrylate accounts for 0.43 wt%, the polyetheretherketone resin accounts for 48 wt%, and the balance is carbon fiber cloth.

[0105] After the sizing agent solution in this case is placed for 15 minutes, it can be seen that the polyetheretherketone resin powder is well dispersed in the aqueous phase and there is no obvious sedimentation phenomenon.

[0106] Example 4

[0107] The preparation method of the polyaryletherketone prepreg in this case is the same as that in Example 1. The difference is that the sizing agent solution formula in S2 is as follows:

[0108] The sizing agent solution formula is as follows: 4 g of core-shell structured acrylate emulsion with a solid content of 37.9 wt% prepared in Preparation Example 4, 90 g of polyetheretherketone resin powder with a particle size of 50 μm (the melt index under the test conditions of 400 °C and 2.16 kg is 22 g / 10 min), 45 g of absolute ethanol, and 350 g of ultrapure water.

[0109] For the polyaryletherketone prepreg prepared in this case, calculated by 100 wt%, the core-shell structured acrylate accounts for 0.91 wt%, the polyetheretherketone resin accounts for 54 wt%, and the balance is carbon fiber cloth.

[0110] After the sizing agent solution in this case is placed for 15 minutes, it can be seen that the polyetheretherketone resin powder is well dispersed in the aqueous phase and there is no obvious sedimentation phenomenon.

[0111] Example 5

[0112] The preparation method of the polyaryletherketone prepreg in this case is the same as that in Example 1. The difference is that the sizing agent solution formula in S2 is as follows:

[0113] The sizing formulation is as follows: 2.5 g of a core-shell structured acrylate emulsion with a solids content of 38.1 wt% from Preparation Example 5, 90 g of polyether ether ketone resin powder with a particle size of 50 μm (melt index of 16 g / 10 min under test conditions of 400 °C and 2.16 kg), 45 g of absolute ethanol, and 350 g of ultrapure water.

[0114] For the polyaryletherketone prepreg prepared in this example, calculated by 100 wt%, the core-shell structured acrylate accounts for 0.48 wt%, the polyether ether ketone resin accounts for 46 wt%, and the balance is carbon fiber cloth.

[0115] After the sizing solution in this example was prepared and left standing for 15 minutes, it was found that the polyether ether ketone resin powder was well dispersed in the aqueous phase and there was no obvious sedimentation phenomenon.

[0116] Comparative Example 1

[0117] The preparation method of the prepreg in this example is the same as that of Example 1, except that in S2, the sizing formulation contains only polyether ether ketone resin powder and water (the amounts used are the same as in Example 1).

[0118] Immediately after the sizing solution in this example was prepared, it was found that the polyether ether ketone resin powder could not be effectively dispersed, as Figure 1 shown.

[0119] Comparative Example 2

[0120] The preparation method of the prepreg in this example is the same as that of Example 1, except that in S2, the sizing formulation is as follows: 1 g of a core-shell structured acrylate emulsion with a solids content of 38.3 wt% from Preparation Example 1, 90 g of polyether ether ketone resin powder with a particle size of 15 μm (melt index of 32 g / 10 min under test conditions of 400 °C and 2.16 kg), 50 g of absolute ethanol, and 350 g of ultrapure water.

[0121] After the sizing solution in this example was prepared and left standing for 3 minutes, it was found that the polyether ether ketone resin powder agglomerated in the sizing solution, as Figure 1 seen, with poor dispersibility and obvious sedimentation phenomenon, indicating that a small amount of the core-shell structured acrylate emulsion could not effectively disperse the PEEK powder.

[0122] The SEM image of the polyaryletherketone prepreg prepared in this example is as Figure 2 shown. The scale bar in the figure is 100 μm. It can be seen that a small amount of the core-shell structured acrylate emulsion could not effectively disperse the polyether ether ketone resin powder, the sizing solution had a poor impregnation effect on the fibers, and there were obvious dry yarns in the carbon fiber.

[0123] The polyaryletherketone prepreg prepared in this example, calculated by 100 wt%, contains 0.23 wt% of core-shell structured acrylate, 49 wt% of polyaryletherketone resin, and the balance is carbon fiber cloth.

[0124] Comparative Example 3

[0125] The preparation method of the prepreg in this example is the same as that of Example 1, except that in S2, the sizing agent formulation uses the core-shell structured acrylate emulsion with a solid content of 38.5 wt% prepared in Preparation Example 6 (the dosage is the same as that in Example 1).

[0126] After the sizing agent in this example was prepared and left standing for 2 minutes, it could be seen that the polyetheretherketone resin powder agglomerated in the sizing agent. As Figure 1 seen, the dispersibility was poor and the sedimentation phenomenon was obvious, indicating that the small amount of core-shell structured acrylate emulsion could not effectively disperse the PEEK powder.

[0127] The polyaryletherketone prepreg prepared in this example, calculated by 100 wt%, contains 0.48 wt% of core-shell structured acrylate, 51 wt% of polyaryletherketone resin, and the balance is carbon fiber cloth.

[0128] The prepregs of the above examples and comparative examples were subjected to performance tests, and the results are shown in Table 2 below.

[0129] Table 2 Performance of prepregs of examples and comparative examples

[0130]

[0131]

[0132] As can be seen from Table 1, in Comparative Example 1, since it does not contain core-shell structured acrylate emulsion and ethanol, PEEK cannot be dispersed in water. In Comparative Example 2, a smaller amount of core-shell structured acrylate emulsion than in Example 1 was used to prepare the sizing agent, and the dispersion stability of the obtained sizing agent decreased, and the interfacial strength and overall mechanical properties of the subsequent prepared prepreg decreased. In Comparative Example 3, the core-shell structured acrylate emulsion prepared in Preparation Example 6 was used to prepare the sizing agent, and the dispersion stability of the obtained sizing agent was not good, and the interfacial strength and overall mechanical properties of the subsequent prepared prepreg were even worse.

[0133] However, when 0.3 - 1 wt% of the core-shell structured acrylate emulsion of the present invention is added to the sizing agent, it can produce good dispersion stability for PEEK in an aqueous alcohol solution, and can effectively enhance the adhesion between the fiber and the PEEK resin, thereby significantly improving the interfacial strength and overall mechanical properties of the composite material. The tensile strength is above 695 MPa, the flexural strength is above 880 MPa, and the mode I interlaminar fracture toughness is above 1350 J / m 2 above.

[0134] The above are only the preferred specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution of the present invention and its inventive concept, making equivalent substitutions or changes, shall be covered by the protection scope of the present invention.

Claims

1. A method for preparing a polyaryletherketone prepreg, characterized in that: The carbon fiber fabric is surface treated with a sizing liquid, and then dried and pressed; The sizing liquid comprises the following materials in 100% by mass: 0.3%-1% of core-shell structure acrylic emulsion, 15%-35% of polyaryletherketone resin powder, 8%-15% of anhydrous ethanol, and the balance is water; The core layer material is a copolymer formed by core layer monomers, and the core layer monomers are (meth)acrylic acid, butyl (meth)acrylate and hydroxyethyl (meth)acrylate; The shell material is a copolymer formed by shell monomers, and the shell monomers are one or more of (meth)acrylic acid and butyl (meth)acrylate, N-(hydroxymethyl) (meth)acrylamide, and hydroxyethyl (meth)acrylate.

2. The method for preparing a polyaryletherketone prepreg according to claim 1, characterized in that: The (meth)acrylic acid, butyl (meth)acrylate and hydroxyethyl (meth)acrylate in the core layer monomer are configured in a mass ratio of 15-50:20-30:2-5; The shell monomers are (meth)acrylic acid, butyl (meth)acrylate and N-(hydroxymethyl) (meth)acrylamide in a mass ratio of 10:2:0.5, or (meth)acrylic acid and one of N-(hydroxymethyl) (meth)acrylamide, butyl (meth)acrylate and hydroxyethyl (meth)acrylate in a mass ratio of 10-15:1-3. Based on the total mass of the shell monomers and the core monomers, the mass percentage ratio of the core monomers to the shell monomers is 70%-85%:15%-30%.

3. The method for preparing a polyaryletherketone prepreg according to claim 2, characterized in that: The polymerization process of the core-shell structure acrylic emulsion includes the following material configuration: A raw material solution, based on the total mass of the shell layer monomer and the core layer monomer, the raw material solution comprises 0.1%-0.5% of an initiator, 0.12%-0.25% of a pH regulator, 0.12%-0.22% of an emulsifier, and 90%-150% of water; A shell layer reaction solution, based on the total mass of the shell layer monomer and the core layer monomer, the shell layer reaction solution comprises 15%-30% of the shell layer monomer and 0.25%-0.8% of the emulsifier; The core layer reaction solution comprises 70%-85% of the core layer monomer and 1.3%-2.5% of the emulsifier based on the total mass of the shell layer monomer and the core layer monomer.

4. The method for preparing a polyaryletherketone prepreg according to claim 3, characterized in that: The polymerization process of the core-shell structure acrylic emulsion comprises the following steps: Prepare the initiator aqueous solution, pH regulator aqueous solution and emulsifier aqueous solution respectively according to the ratio requirements; Add part of the emulsifier aqueous solution to the pH control agent aqueous solution, add part of the core layer reaction solution and heat it to 75-80° C. under continuous stirring, add part of the initiator aqueous solution, continue to react for 5-15 minutes after the system turns blue, dropwise add the remaining part of the core layer reaction solution and part of the initiator aqueous solution within 1.5-2.5 hours, continue to react for 50-80 minutes after the dropwise addition is completed, then dropwise add the shell layer reaction solution and the remaining part of the initiator aqueous solution, continue to react for 20-40 minutes after the dropwise addition is completed, heat it to 80-90° C. and continue to react for 50-80 minutes, then cool it, and adjust the pH value to 7-8 to obtain a core-shell structure acrylic emulsion; the solid content of the core-shell structure acrylic emulsion is at least 35wt%.

5. The method for preparing a polyaryletherketone prepreg according to claim 4, characterized in that: The pH regulator is sodium bicarbonate; the emulsifier is selected from one or more of sodium dodecyl sulfate, sodium stearate, and sodium hexadecyl sulfonate; and the initiator is selected from potassium persulfate and / or ammonium persulfate.

6. A method for preparing a polyaryletherketone prepreg according to any one of claims 1 to 5, characterized in that: The polyaryletherketone powder is selected from one or more of polyetheretherketone, polyetherketone, and polyetherketoneetherketone. The melt index of the polyaryletherketone powder is greater than 15g / 10min under the test conditions of 400°C and 2.16kg, and the particle size in the powder does not exceed 50μm.

7. A method for preparing a polyaryletherketone prepreg according to any one of claims 1 to 5, characterized in that: The order of adding materials in the preparation process of the sizing liquid is: adding anhydrous ethanol to the core-shell structure acrylic emulsion and stirring for 10-20 minutes, adding polyaryletherketone resin powder, and after uniform dispersion, adding water to adjust the concentration, and continuously stirring for 15-30 minutes.

8. The method for preparing a polyaryletherketone prepreg according to any one of claims 1 to 5, characterized in that: The surface treatment is spraying or dipping, and the surface treatment time is controlled according to the sizing amount; the carbon fiber fabric needs to be desizing before the surface treatment; the pressing temperature is 380-420° C. and the pressing time is 30-60 seconds.

9. The polyaryletherketone prepreg obtained by the preparation method according to any one of claims 1 to 8, characterized in that: In the polyaryletherketone prepreg, based on 100% by mass, core-shell structure acrylate accounts for 0.3%-2.0%, polyaryletherketone resin accounts for 40%-60%, and the remainder is carbon fiber fabric.

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