Preparation method of carbon fiber sizing agent for PEEK resin matrix

Abstract

The invention is applied to the technical field of carbon fiber sizing agents, and discloses a preparation method of a carbon fiber sizing agent for a PEEK resin matrix, and the preparation method of the sizing agent comprises the following steps: S1, dissolving a substance A in a solvent C at the dissolving temperature of 25-45 DEG C, and mechanically stirring; and S2, dissolving the substance B in the solution prepared in S1, and mechanically stirring. According to the preparation method of the carbon fiber sizing agent for the PEEK resin matrix, the sizing agent can form firm and stable interface bonding with the PEEK resin matrix, a substance A and a substance B are sequentially dissolved and mixed, so that the substance A and the substance B fully react, and the generated substance structure is beneficial to enhancing the interaction with carbon fibers and PEEK resin; the problem of interface debonding when the composite material bears load is effectively avoided, so that the strength and the reliability of the composite material are remarkably improved, and the performance of a structural member in a complex stress environment is greatly improved.

Description

Technical Field

[0001] The present invention relates to the technical field of carbon fiber sizing agents, and particularly to a preparation method of a carbon fiber sizing agent for a PEEK resin matrix. Background Art

[0002] In the field of high-performance composite materials, carbon fiber reinforced polymer matrix composites are widely used in many fields such as aerospace, automotive industry, and sporting goods due to their excellent properties, such as high specific strength, high specific modulus, fatigue resistance, etc. Among them, PEEK (polyetheretherketone) resin, as a high-performance thermoplastic resin matrix, has outstanding high temperature resistance, chemical corrosion resistance, good mechanical properties, and processability, and has become one of the ideal matrix choices for carbon fiber reinforced composites;

[0003] The surface of carbon fiber is relatively smooth, with low chemical activity and weak interfacial bonding force with the resin matrix, which seriously affects the overall performance of the composite material. As a key material to improve the interfacial performance between carbon fiber and resin matrix, the performance of the sizing agent directly affects the comprehensive performance of the composite material. At present, there are still many problems in the actual application of carbon fiber sizing agents for PEEK resin matrices. When traditional sizing agents are compounded with PEEK resin matrices, it is difficult to form a firm and stable interfacial bond, resulting in easy interfacial debonding when the composite material bears load, reducing the strength and reliability of the material. Moreover, the preparation process of some sizing agents is complex and the cost is high, which is not conducive to large-scale industrial production. At the same time, the stability of some sizing agents under different environmental conditions is poor, affecting the storage and use performance of carbon fiber. Therefore, it is of great practical significance to develop a sizing agent that can effectively improve the interfacial performance between carbon fiber and PEEK resin matrix, has a simple preparation process, and a reasonable cost. Summary of the Invention

[0004] The purpose of the present invention is to provide a preparation method of a carbon fiber sizing agent for a PEEK resin matrix to solve the problems of weak interfacial bonding, poor stability, resulting in reduced strength and reliability of the composite material, complex preparation process, high cost, and poor stability under different environmental conditions as proposed in the above background art.

[0005] To achieve the above purpose, the present invention provides the following technical solution: A preparation method of a carbon fiber sizing agent for a PEEK resin matrix, the preparation method of the sizing agent includes the following steps:

[0006] S1. Dissolve substance A in solvent C at a dissolution temperature of 25 - 45 °C, and use mechanical stirring;

[0007] S2. Dissolve substance B in the solution obtained in S1, and use mechanical stirring;

[0008] S3. Consolidate the melt generated in S2 at a low temperature;

[0009] S4. Crush the solid obtained in S3 using a low-temperature crusher;

[0010] S5. Disperse the solid powder obtained in S4 in solvent D using a high-speed disperser to obtain a suspension.

[0011] Preferably, the stirring speed in S1 is 100 rpm - 500 rpm, and the stirring time is 5 - 15 min.

[0012] Preferably, the solvent C in S1 is one or a mixture of two of N-methylpyrrolidone, dimethylformamide, and dimethylacetamide.

[0013] Preferably, the concentration of substance A in solvent C in S1 is 1% - 5% wt.

[0014] Preferably, substance A is a polymer, and its monomer molecular structure is as follows:

[0015]

[0016] Preferably, the dissolution temperature in S2 is 35 - 55 °C, the stirring speed in S2 is 100 rpm - 500 rpm, and the stirring time is 15 - 130 min.

[0017] Preferably, substance B is a polymer, and its monomer molecular structure is as follows:

[0018]

[0019] Preferably, the consolidation temperature in S3 is -18 °C to -30 °C.

[0020] Preferably, the particle size of the solid crushed in S4 is less than 1 μm.

[0021] Preferably, the solvent D in S5 is one or a mixture of two of water, ethanol, and acetone.

[0022] Compared with the prior art, the beneficial effects of the present invention are: The preparation method of the sizing agent for carbon fiber for PEEK resin matrix:

[0023] 1. The sizing agent of the present invention can form a firm and stable interfacial bond with the PEEK resin matrix. By dissolving and mixing substance A and substance B successively, the two substances react fully, and the resulting substance structure helps to enhance the interaction with carbon fiber and PEEK resin, effectively avoiding the problem of interfacial debonding when the composite material bears load, thus significantly improving the strength and reliability of the composite material and greatly enhancing the performance of the structural member in a complex stress environment;

[0024] 2. The entire preparation process is clear and the steps are concise. Only conventional operations such as dissolution, consolidation, crushing, and dispersion need to be carried out in sequence. Compared with the complex preparation process of traditional sizing agents, multiple cumbersome intermediate links and the use of special equipment are reduced. Traditional sizing agents require multiple chemical reactions and precise control of reaction conditions, while the present invention can complete each step of operation within a relatively wide range of temperature and stirring speed, reducing the difficulty of process control and improving production efficiency.

[0025] 3. From the perspective of raw materials, both solvent C and solvent D used in the present invention are common and relatively inexpensive industrial solvents, with wide sources and controllable costs. On the other hand, due to the simple preparation process, equipment investment, energy consumption, and labor costs are reduced, providing a strong cost advantage for large-scale industrial production.

[0026] 4. In the preparation process of the present invention, through means such as low-temperature consolidation and controlling the particle size of solid crushing, the finally prepared sizing agent has better stability under different environmental conditions. Whether in a storage environment of high temperature and high humidity or in a processing and use environment of different temperatures, the sizing agent can maintain the consistency of its performance, effectively avoiding performance degradation caused by environmental factors and extending the storage period and stability of the use performance of carbon fiber. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a comparative diagram of SEM micrographs of carbon fiber before and after surface treatment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0028] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in 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. 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 protection scope of the present invention.

[0029] Please refer to Figure 1 , the present invention provides a technical solution: a preparation method of a sizing agent for carbon fiber for PEEK resin matrix, and the preparation method of the sizing agent includes the following steps:

[0030] S1. Dissolve substance A in solvent C, the dissolution temperature is 25 - 45 °C, mechanical stirring is used, the stirring speed is 100 - 500 rpm, and the stirring time is 5 - 15 min. Solvent C is one or a mixture of two of N-methylpyrrolidone, dimethylformamide, and dimethylacetamide, and the concentration of substance A in solvent C is 1% - 5% wt.

[0031] Substance A is a polymer, and its monomer molecular structure is as follows:

[0032]

[0033] S2. Dissolve Substance B in the solution obtained in S1, and use mechanical stirring. The dissolution temperature is 35 - 55°C, the stirring speed in S2 is 100 - 500 rpm, and the stirring time is 15 - 130 min;

[0034] Substance B is a polymer, and its monomer molecular structure is as follows:

[0035]

[0036] S3. Solidify the solution formed in S2 at a low temperature. The solidification temperature is 18°C to 30°C;

[0037] S4. Crush the solid obtained in S3 using a low-temperature crusher. The particle size of the solid after crushing is less than 1 μm;

[0038] S5. Disperse the solid powder obtained in S4 in Solvent D using a high-speed disperser to obtain a suspension. Solvent D is one or a mixture of two of water, ethanol, and acetone.

[0039] The following are three examples of the preparation of a sizing agent for carbon fiber based on PEEK resin matrix, including the specific preparation process and simulated experimental data.

[0040] Example 1

[0041] Preparation Process

[0042] 1. S1: In a reaction kettle equipped with a mechanical stirring device, add N-methylpyrrolidone as Solvent C, and slowly add Substance A of the polymer to Solvent C. Control the dissolution temperature at 25°C, turn on the mechanical stirring, set the stirring speed at 100 rpm, and stir for 15 min to fully dissolve Substance A. The concentration of Substance A in Solvent C is 1% wt;

[0043] 2. S2: Add Substance B of the polymer to the solution obtained in S1, adjust the dissolution temperature to 35°C, the stirring speed to 100 rpm, and the stirring time to 130 min to ensure that Substance B is completely dissolved;

[0044] 3. S3: Transfer the solution formed in S2 to a low-temperature environment and control the solidification temperature at 18°C to solidify the solution;

[0045] 4. S4: Take out the solidified solid, use a low-temperature crusher to crush it, and control the particle size of the solid after crushing to be less than 1 μm;

[0046] 5.S5: Add the crushed solid powder into a high-speed disperser filled with water, and disperse to obtain a suspension, namely, the sizing agent for carbon fiber for PEEK resin matrix is obtained.

[0047] Experimental data

[0048] Interfacial shear strength: Use the prepared sizing agent to treat carbon fiber and compound it with PEEK resin to prepare a composite material sample. Through testing, the interfacial shear strength of this composite material is 45 MPa, which is 25% higher than that of traditional materials.

[0049] Cost: The preparation cost of each kilogram of sizing agent is 10 - 15 yuan.

[0050] Stability: After storing the treated carbon fiber in an environment of 60 °C and 80% humidity for 6 months, the tensile strength retention rate is 90%.

[0051] Example 2

[0052] Preparation process

[0053] 1.S1: Add dimethylformamide as solvent C into the reaction kettle, add substance A into it, control the dissolution temperature at 35 °C, the mechanical stirring speed at 300 rpm, stir for 10 min, and the concentration of substance A is 3% wt;

[0054] 2.S2: Add substance B into the S1 solution, adjust the dissolution temperature to 45 °C, and the stirring speed to 300 rpm, stir for 70 min;

[0055] 3.S3: Solidify the solution in a low-temperature environment of 24 °C;

[0056] 4.S4: Crush the solidified solid with a low-temperature crusher to make the particle size less than 1 μm;

[0057] 5.S5: Disperse the solid powder in ethanol with a high-speed disperser to obtain a sizing agent in suspension form.

[0058] Experimental data

[0059] Interfacial shear strength: The interfacial shear strength of the prepared composite material reaches 47 MPa, which is 30.5% higher than that of traditional materials.

[0060] Cost: The cost of each kilogram of sizing agent is about 10 yuan.

[0061] Stability: After storing the treated carbon fiber in the above temperature and humidity environment for 6 months, the tensile strength retention rate is 93%.

[0062] Example 3

[0063] Preparation process

[0064] 1. S1: Using dimethylacetamide as solvent C, add substance A. The dissolution temperature is 45°C, the stirring speed is 500 rpm, stir for 5 min, and the concentration of substance A is 5% wt.

[0065] 2. S2: Add substance B to the S1 solution. The dissolution temperature is 55°C, the stirring speed is 500 rpm, and stir for 15 min.

[0066] 3. S3: Consolidate the solution in a low-temperature environment of 30°C.

[0067] 4. S4: Crush the consolidated solid to make the particle size less than 1 μm.

[0068] 5. S5: Disperse the powder in acetone with a high-speed disperser to make a sizing agent suspension.

[0069] Experimental data

[0070] Interfacial shear strength: The interfacial shear strength of the composite material is 49 MPa, which is 36.1% higher than that of traditional materials.

[0071] Cost: The cost of each kilogram of sizing agent is about 5 - 10 yuan.

[0072] Stability: After the treated carbon fiber is stored in an environment of 60°C and 80% humidity for 6 months, the tensile strength retention rate is 95%.

[0073] Instruction manual appendix Figure 1 On the left in the figure is the microscopic SEM photo of the carbon fiber before surface treatment, and on the right is the microscopic SEM photo of the carbon fiber treated with the sizing agent. It can be seen from the SEM pictures that the surface of the sized carbon fiber is coated with a resin film, while there is no resin layer on the surface of the carbon fiber before surface treatment.

[0074] In the above specific embodiments, the purpose, technical solution, and beneficial effects of the present invention are further described in detail. It should be understood that the above are only specific embodiments of the present invention and do not limit the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention are included in the protection scope of the present invention.

Claims

1. A method for preparing a carbon fiber sizing agent for a PEEK resin matrix, characterized in that: The method for preparing the sizing dosage comprises the following steps: S1. Dissolve substance A in solvent C at a dissolving temperature of 25-45°C with mechanical stirring; S2, dissolving substance B in the solution prepared in S1, using mechanical stirring; S3, solidifying the melt generated in S2 at low temperature; S4, crushing the solid obtained in S3 using a low-temperature crusher; S5. Dispersing the solid powder obtained in S4 in solvent D by using a high-speed disperser to obtain a suspension.

2. The method for preparing a carbon fiber sizing agent for a PEEK resin matrix according to claim 1, characterized in that: The stirring speed in S1 is 100 rpm-500 rpm, and the stirring time is 5-15 min.

3. The method for preparing a carbon fiber sizing agent for a PEEK resin matrix according to claim 1, characterized in that: The solvent C in S1 is one of nitrogen methyl pyrrolidone, dimethylformamide, and dimethylacetamide, or a mixture of two thereof.

4. The method for preparing a carbon fiber sizing agent for a PEEK resin matrix according to claim 1, characterized in that: The concentration of substance A in the solvent C in S1 is 1%-5%wt.

5. The method for preparing a carbon fiber sizing agent for a PEEK resin matrix according to claim 1, characterized in that: The substance A is a polymer, and its monomer molecular structure is as follows:

6. The method for preparing a carbon fiber sizing agent for a PEEK resin matrix according to claim 1, characterized in that: The dissolving temperature in the S2 is 35-55° C., the stirring speed in the S2 is 100 rpm-500 rpm, and the stirring time is 15-130 min.

7. The method for preparing a carbon fiber sizing agent for a PEEK resin matrix according to claim 1, characterized in that: The substance B is a polymer, and its monomer molecular structure is as follows:

8. The method for preparing a carbon fiber sizing agent for a PEEK resin matrix according to claim 1, characterized in that: The consolidation temperature in S3 is -18°C to -30°C.

9. The method for preparing a carbon fiber sizing agent for a PEEK resin matrix according to claim 1, characterized in that: The solid crushed particle size in the S4 is less than 1 μm.

10. The method for preparing a carbon fiber sizing agent for a PEEK resin matrix according to claim 1, characterized in that: The solvent D in S5 is one of water, ethanol and acetone or a mixture of two of them.

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