Innovative preparation method and application of high-strength long carbon fiber reinforced high-performance composite engineering plastic

Abstract

The invention provides an innovative preparation method and application of high-strength long carbon fiber reinforced high-performance composite engineering plastic, belongs to the field of carbon fiber reinforced advanced intelligent composite materials, and aims at remarkably improving the mechanical property of a traditional polymer material. The method comprises the following steps: dissolving PEI in an NMP solution, then dipping cut carbon fiber cloth in the PEI solution, sequentially laminating, and finally preparing the composite engineering plastic with excellent strength, rigidity and high-temperature resistance by using a vacuum filtration and high-temperature curing process. The material not only has the characteristics of high strength and light weight, but also has excellent corrosion resistance and design flexibility, the optimal combination of the carbon fibers and the PEI matrix is ensured through reasonable operation steps and optimal design, and the mechanical property of the composite material is remarkably improved. The method is especially suitable for the fields of aerospace, automobile manufacturing and the like with extremely high material performance requirements.

Description

Technical Field

[0001] The present invention belongs to the field of carbon fiber reinforced advanced intelligent composite materials and relates to a preparation method and application of carbon fiber reinforced composite engineering plastics. Background Art

[0002] In the field of advanced intelligent composite materials, carbon fiber reinforced composites (CFRPs) have attracted significant attention due to their exceptional performance characteristics. Carbon fibers offer high strength, high modulus, low density, and excellent heat resistance, while engineering plastics offer excellent chemical and heat resistance and mechanical properties. Combining the two can fully leverage their respective strengths to create composite materials with even higher performance.

[0003] Polyetherimide (PEI) is a translucent, amber-colored, high-performance polymer with exceptional strength, heat resistance, modulus, corrosion resistance, and wear resistance. It is widely used in applications such as automotive, communications, aerospace, electrical and electronics, transportation, and healthcare. Its excellent mechanical properties have earned it the nickname "the material of choice for large aircraft." However, with increasing demand for existing materials, the need for mechanical properties beyond their inherent capabilities is emerging.

[0004] Against this backdrop, it is necessary to improve and optimize polyetherimide to meet the performance requirements of composite materials in various applications. Compared to other filler materials, carbon fiber stands out for its excellent mechanical properties. Due to its inherently high strength and stiffness, the addition of carbon fiber can significantly enhance the strength and stiffness of composites, providing enhanced tensile, compressive, and flexural resistance. Furthermore, its extremely low density allows for lightweight composites, reducing structural loads and increasing specific strength and stiffness, making it particularly suitable for applications requiring lightweight yet high strength. Furthermore, carbon fiber exhibits excellent high-temperature resistance, maintaining stable mechanical properties even in high-temperature environments. Therefore, its addition can enhance the heat resistance of composites, ensuring excellent performance even in these conditions. Its excellent chemical stability makes it resistant to corrosive media such as acids and alkalis, thereby improving the corrosion resistance of composites and extending their service life. Finally, during the preparation process, considerations such as orientation and layer stacking must be taken into account. The carbon fibers must be cut and processed according to a pre-designed distribution. Custom designs can be tailored to meet specific structural and performance requirements based on specific application needs.

[0005] In summary, the optimization of polyetherimide with carbon fiber as the filling material has higher strength, lighter weight, better heat resistance and corrosion resistance than ordinary filling materials, and has better design flexibility. Therefore, the research and development of a carbon fiber reinforced advanced intelligent composite material with good mechanical properties has broad application prospects and huge economic benefits. In response to the problems existing in the existing preparation process and the problems existing in the ratio of fiber to matrix and other processes, the present invention proposes a new preparation process of carbon fiber reinforced composite engineering plastics. Through reasonable operation and calculation, the optimal performance combination between polyetherimide and carbon fiber is obtained, which provides a certain reference for the development of the field of engineering plastics. Summary of the Invention

[0006] The present invention provides a novel method for preparing carbon fiber reinforced composite engineering plastics, aiming to solve the technical problem of poor mechanical properties of single-phase polymer materials.

[0007] The present invention provides a method for preparing high-strength long carbon fiber reinforced high-performance composite engineering plastics, comprising the following steps:

[0008] Step 1: Add polyetherimide powder to N-methylpyrrolidone solution and stir until dissolved;

[0009] Step 2: Place PI tape, release cloth, sealing ring glue, and vacuum film on the clean and flat aluminum plate surface in sequence, and place carbon fiber cloth, vacuum duct, and filter tip on the edge inside the sealing ring glue;

[0010] Step 3: Cut the carbon fiber cloth of the required size and quantity, and immerse the carbon fiber cloth in the solution prepared in step 1;

[0011] Step 4: Stack the fully impregnated carbon fiber cloth layer by layer on the inside of the sealing ring glue and cover it with release cloth;

[0012] Step 5: Cover the seal with vacuum film and connect the seal end to an air pump for vacuum filtration;

[0013] Step 6: The aluminum plate is cured as a whole at a curing temperature of 150°C for 12 hours. The sample is taken out and cooled to obtain a high-strength long carbon fiber reinforced high-performance composite engineering plastic.

[0014] Furthermore, in step 1, the polyetherimide powder is dissolved at a temperature of 60 to 80° C., the concentration of the polyetherimide is 3 g / mol, and the dissolution is performed by ultrasonic dissolution with an ultrasonic power of 750 W and a time of 15 to 20 minutes.

[0015] Furthermore, in step 3, the mass ratio of the carbon fiber cloth to the solution is 2:1.

[0016] Furthermore, in step 3, the carbon fiber cloth is treated with oxygen plasma to enhance the interfacial bonding between the fiber and the matrix.

[0017] Furthermore, in step 6, the curing process adopts staged temperature curing; the temperature of the stages is: the temperature of the first stage is 80°C, the time is 1 hour; the temperature of the second stage is 120°C, the time is 2 hours; the temperature of the third stage is 150°C.

[0018] Beneficial effects of the present invention:

[0019] The method of the present invention is to dissolve polyetherimide (PEI) in N-methylpyrrolidone (NMP) solution, then immerse the cut carbon fiber cloth in the PEI solution, stack them in sequence and use vacuum filtration and high-temperature curing process to finally prepare a composite engineering plastic with excellent strength, rigidity and high-temperature resistance. This material not only has high strength and lightweight characteristics, but also has excellent corrosion resistance and design flexibility. Through reasonable operating steps and optimized design, the optimal combination of carbon fiber and PEI matrix is ensured, and a significant improvement in the mechanical properties of the composite material is achieved. It is particularly suitable for fields such as aerospace, automobile manufacturing, etc. that have extremely high requirements for material performance. The preparation process of the present invention is simple and effective, has broad application prospects and significant economic benefits, and is suitable for various industrial fields with growing demand for high-performance composite materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 Schematic diagram of the preparation arrangement of the carbon fiber reinforced composite engineering plastic of the present invention;

[0021] Figure 2 The contact angle between the fiber and the solution during the impregnation process of the present invention. DETAILED DESCRIPTION

[0022] The present invention will be further described below with reference to the accompanying drawings.

[0023] The present invention discloses a novel method for preparing carbon fiber reinforced composite engineering plastics, the steps of which are as follows:

[0024] Step 1: Preparation of PEI Solution: Add polyetherimide (PEI) powder to N-methylpyrrolidone (NMP) solution and stir at 60-80°C until the PEI powder is completely dissolved. To optimize the dissolution process, ultrasonic stirring is used to improve dissolution efficiency at a power of 750W for 15-20 minutes to reduce residual bubbles.

[0025] Step 2: Cutting the carbon fiber cloth: Cut the carbon fiber cloth to the appropriate size, and prepare 8 pieces of the same size. To improve the performance of the composite material, functional interface treatment is added between the different layers of carbon fiber cloth. The specific operation is to use oxygen plasma treatment to enhance the interfacial bonding between the fiber and the matrix.

[0026] Step 3: Preparation of mold: Place PI tape, demoulding cloth, sealing ring glue, vacuum film on the clean and flat surface of aluminum plate in sequence, and place fiber cloth, vacuum duct and filter tip on the edge of the sealing ring glue, as shown in the attached figure. Figure 1 As shown. Introducing mold materials with high thermal conductivity and reusability to improve heat conduction efficiency and manufacturing stability.

[0027] Step 4: Impregnation process: Place the cut carbon fiber cloth into the solution prepared in step 1 and impregnate it, ensuring that each layer of fiber is completely wet. The mass ratio of carbon fiber cloth to solution is 2:1. In order to improve the uniformity and depth of impregnation, mechanical vibration is applied during the impregnation process. Figure 2 The contact angle between the solution and the fiber is shown. The smaller the contact angle, the better the bonding between the fiber and the PEI solution, which provides a basis for the material's good mechanical properties.

[0028] Step 5: Laminating Carbon Fiber Cloth: Layer the fully impregnated carbon fiber cloth inside the seal ring and cover it with release cloth. The PEI and carbon fiber cloth between each layer interlock to improve the mechanical properties of the composite material.

[0029] Step 6: Vacuum filtration: Cover the seal with vacuum film and connect the sealed end to an air pump for vacuum filtration to ensure that the bubbles are completely discharged, improve the density and uniformity of the material to achieve more efficient degassing and filtration effects.

[0030] Step 7: Heating and curing: Place the entire aluminum plate on a heating platform at a temperature of 150°C for 12 hours. Optimize the curing process through a staged heating program to avoid damage to the matrix caused by internal stress generated by high temperature, ensuring the mechanical properties and dimensional stability of the material. The temperature of the stages: the first stage is 80°C for 1 hour, a preheating stage to promote resin flow and infiltration and remove bubbles; the second stage is 120°C for 2 hours, preliminary curing to start the cross-linking reaction; the third stage is 150°C for complete curing, the reaction is fully completed, and the structural strength is ensured.

[0031] Step 8: Cooling and Sampling: Remove the sample and cool it to room temperature to obtain the final carbon fiber reinforced composite engineering plastic. This gradual cooling process can reduce deformation or cracking caused by thermal expansion differences.

[0032] Example 1

[0033] The preparation method of a carbon fiber reinforced composite engineering plastic of this embodiment is carried out by the following steps:

[0034] Step 1: Add 30 g of PEI powder to 10 mL of NMP solution and stir at 75°C until the PEI powder is completely dissolved.

[0035] Step 2: Cut the carbon fiber cloth into the appropriate size of 6×8cm. Prepare 8 pieces of carbon fiber cloth of the same size.

[0036] Step 3: Place PI tape, release cloth, sealing ring glue, and vacuum film on the clean and flat surface of the aluminum plate in sequence, and place fiber cloth, vacuum duct and filter tip on the edge inside the sealing ring glue.

[0037] Step 4: Dip the cut carbon fiber cloth into the solution prepared in step 1.

[0038] Step 5: Stack the fully impregnated carbon fiber cloth layer by layer inside the sealing ring glue and cover it with release cloth.

[0039] Step 6: Cover the seal with vacuum film and connect the sealed end to an air pump for vacuum filtration to ensure that the air is completely exhausted.

[0040] Step 7: Place the aluminum plate on a heating platform at 150°C for 12 hours.

[0041] Step 8: Take out the sample and cool it to room temperature to obtain the final carbon fiber reinforced composite engineering plastic.

[0042] Comparative Example 1

[0043] The preparation method of a carbon fiber reinforced composite engineering plastic of this comparative example is carried out by the following steps:

[0044] Step 1: Add 30 g of PEI powder to 10 mL of NMP solution and stir at 75°C until the PEI powder is completely dissolved.

[0045] Step 2: Cut the carbon fiber cloth into the appropriate size of 6×8cm. Prepare 8 pieces of carbon fiber cloth of the same size.

[0046] Step 3: Place PI tape, release cloth, sealing ring glue, and vacuum film on the clean and flat surface of the aluminum plate in sequence, and place fiber cloth, vacuum duct and filter tip on the edge inside the sealing ring glue.

[0047] Step 4: Dip the cut carbon fiber cloth into the solution prepared in step 1.

[0048] Step 5: Stack the fully impregnated carbon fiber cloth layer by layer inside the sealing ring glue and cover it with release cloth.

[0049] Step 6: Cover the seal with vacuum film and connect the sealed end to an air pump for vacuum filtration to ensure that the air is completely exhausted.

[0050] Step 7: Place the aluminum plate on a heating platform at 100°C for 24 hours.

[0051] Step 8: Take out the sample and cool it to room temperature to obtain the final carbon fiber reinforced composite engineering plastic.

[0052] Comparative Example 1, compared to Example 1, employed a lower temperature and prolonged curing to produce a carbon fiber-reinforced composite engineering plastic. However, low-temperature curing prolonged production time, resulting in poorer material strength and heat resistance. Although vacuum filtration was employed, the negative pressure environment failed to fully promote the bonding of PEI and carbon fibers, impacting the overall performance of the material. The carbon fiber-reinforced composite engineering plastic obtained in Comparative Example 1 exhibited warping and delamination.

[0053] Comparative Example 2

[0054] The preparation method of a carbon fiber reinforced composite engineering plastic of this comparative example is carried out by the following steps:

[0055] Step 1: Add 30 g of PEI powder to 10 mL of NMP solution and stir at 75°C until the PEI powder is completely dissolved.

[0056] Step 2: Cut the carbon fiber cloth into the appropriate size of 6×8cm. Prepare 8 pieces of carbon fiber cloth of the same size.

[0057] Step 3: Lay PI tape and release cloth on the clean and flat surface of the aluminum plate in sequence without using additional equipment and materials such as vacuum film, sealing ring glue, vacuum duct, etc.

[0058] Step 4: Impregnate the cut carbon fiber cloth into the solution prepared in step 1, but do not use vacuum filtration. Directly stack the impregnated carbon fiber cloth on the aluminum plate and cover it with a release cloth.

[0059] Step 5: Place the aluminum plate on a heating platform at 150°C for 12 hours.

[0060] Step 6: Take out the sample and cool it to room temperature to obtain the final carbon fiber reinforced composite engineering plastic.

[0061] Compared to Example 1, Comparative Example 2 did not employ vacuum filtration, resulting in bubbles during the experiment. Without the constraints of a negative pressure environment, the material in Comparative Example 2 was less dense, significantly reducing its strength and durability. The lack of vacuum filtration made it difficult to effectively remove bubbles and excess solution from the solution, resulting in inferior product quality and performance.

[0062] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing high-strength long carbon fiber reinforced high-performance composite engineering plastics, characterized in that: The following steps are involved: Step 1: Add polyetherimide powder to N-methylpyrrolidone solution and stir until dissolved; Step 2: Place PI tape, release cloth, sealing ring glue, and vacuum film on the clean and flat aluminum plate surface in sequence, and place carbon fiber cloth, vacuum duct, and filter tip on the edge inside the sealing ring glue; Step 3: Cut the carbon fiber cloth of the required size and quantity, and immerse the carbon fiber cloth in the solution prepared in step 1; Step 4: Stack the fully impregnated carbon fiber cloth layer by layer on the inside of the sealing ring glue and cover it with release cloth; Step 5: Cover the seal with vacuum film and connect the seal end to an air pump for vacuum filtration; Step 6: The aluminum plate is cured as a whole at a curing temperature of 150°C for 12 hours. The sample is taken out and cooled to obtain a high-strength long carbon fiber reinforced high-performance composite engineering plastic.

2. The method for preparing a high-strength long carbon fiber reinforced high-performance composite engineering plastic according to claim 1, characterized in that: In step 1, the dissolution temperature of the polyetherimide powder is 60-80° C., and the concentration of polyetherimide is 3 g / mL; the dissolution is performed by ultrasonic dissolution with an ultrasonic power of 750 W and a time of 15-20 min.

3. The method for preparing a high-strength long carbon fiber reinforced high-performance composite engineering plastic according to claim 1, characterized in that: In step 3, the mass ratio of the carbon fiber cloth to the solution is 2:

1.

4. The method for preparing a high-strength long carbon fiber reinforced high-performance composite engineering plastic according to claim 1, characterized in that: In step 3, the carbon fiber cloth is treated with oxygen plasma to enhance the interface bonding between the fiber and the matrix.

5. The method for preparing a high-strength long carbon fiber reinforced high-performance composite engineering plastic according to claim 1, characterized in that: In step 6, the curing process adopts staged temperature curing; the temperature of the stages is: the temperature of the first stage is 80°C, the time is 1 hour; the temperature of the second stage is 120°C, the time is 2 hours; the temperature of the third stage is 150°C.

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