High-toughness carbon fiber reinforced resin-based impact-resistant composite board and preparation method

Abstract

This invention belongs to the field of protective engineering technology and discloses a high-toughness carbon fiber reinforced resin-based impact-resistant composite plate and its preparation method. The composite plate is composed of surface-treated carbon fiber cloth and modified epoxy resin. By surface-treating the fiber cloth and modifying the epoxy resin, the toughness of the carbon fiber reinforced epoxy resin composite plate is improved, thereby enhancing its ability to withstand impacts. Furthermore, the preparation process is simple, and all raw materials involved are industrially available products, demonstrating good prospects for large-scale industrial production.

Description

Technical Field

[0001] This invention belongs to the field of protective engineering technology and relates to a high-toughness carbon fiber reinforced resin-based impact-resistant composite plate and its preparation method. Background Technology

[0002] In recent years, with the continuous evolution of warfare, the demand for protective materials has been increasing. However, traditional protective materials, such as steel plates, despite their high strength and impact resistance, face a significant problem: weight. Heavy protective materials not only limit the mobility of equipment during application but also increase transportation costs considerably. Therefore, lightweight protective materials have become an urgent need in the field of protection.

[0003] Carbon fiber reinforced epoxy resin materials possess advantages such as high strength, low density, good corrosion resistance, good fatigue performance, and design freedom, which can meet the needs of lightweight protective materials to a certain extent. Although carbon fiber has excellent strength and stiffness, carbon fiber reinforced epoxy resin materials can exhibit brittleness in certain situations, and may easily break or crack under impact or severe deformation. Therefore, improving the toughness of carbon fiber reinforced epoxy resin materials is of great significance. Summary of the Invention

[0004] To compensate for the insufficient toughness of existing carbon fiber reinforced epoxy resin materials, this invention provides a high-toughness carbon fiber reinforced resin-based impact-resistant composite plate. This composite plate is composed of modified epoxy resin and plasma-treated carbon fiber cloth. Plasma is used to corrode and oxidize the carbon fibers, forming free radicals and active groups on the fiber surface to increase adhesion to the matrix resin. Furthermore, a modifier is used to modify the epoxy resin, thereby improving the toughness of the resin matrix. Together, these factors contribute to the toughening effect of the carbon fiber reinforced epoxy resin composite material. Moreover, the preparation method of this composite material is relatively simple, and the raw materials used are all industrially available products, making it of significant practical importance for the large-scale application of this material.

[0005] The present invention provides a method for preparing a high-toughness carbon fiber reinforced resin-based impact-resistant composite plate, which is carried out according to the following steps:

[0006] 1) Preparation of modified epoxy resin: Thermoplastic resin powder is dissolved in epoxy resin monomer at 140℃ for a certain period of time until no obvious powder is visible; the above sample is placed in a vacuum oven to degas until the air bubbles are completely removed; the curing agent is added to the above blend at 120℃ until it is stirred evenly; the above sample is placed in an oven and the temperature is increased to 180℃ at a rate of 1℃ / min and enters a stable state, and is maintained at 180℃ to achieve complete resin curing.

[0007] 2) Preparation of modified epoxy resin solution: The cured modified epoxy resin is ground into powder and then added to an organic solvent in a certain mass ratio to prepare the modified epoxy resin solution.

[0008] 3) Carbon fiber cloth treatment: Soak the carbon fiber cloth in acetone at room temperature for 6-24 hours to remove surface impurities, and then keep it at 90-110℃ for 0.5-3 hours in a vacuum chamber; then place the carbon fiber cloth into an inductively coupled plasma reactor (the system includes at least one vacuum chamber, one mass flow controller, a maximum operating pressure of 100 Pa, and a maximum power of 1000 W); introduce oxygen into the vacuum chamber at a flow rate of 2-7 standard state cubic centimeters per minute, set the operating pressure to 5-50 Pa, and treat with oxygen plasma with a power of 200-700 W for 1-10 minutes.

[0009] 4) Prepreg preparation: The carbon fiber cloth is impregnated with adhesive solution using the coating method, and the organic solvent is removed by heating to obtain the prepreg; the prepreg is stacked and hot-pressed and cured in a molding machine according to the optimized hot pressing molding process; after the mold cools down to below 40°C, the composite board is demolded to obtain the carbon fiber reinforced modified epoxy resin composite board.

[0010] Preferably, in step 1), the thermoplastic resin is one or both of phenolphthalein polyaryletherketone (PEK) and polyethersulfone (PESU).

[0011] Preferably, in step 1), the epoxy resin is a high-temperature curing resin suitable for liquid molding, such as 4,4-diaminodiphenylmethane tetraglycidylamine (TGDDM) high-temperature resistant epoxy resin or N,N,O-triglycidyl-p-aminophenol (TGAP) trifunctional epoxy resin.

[0012] Preferably, in step 1), the curing agent is 4,4-diaminodiphenyl sulfone (4,4′-DDS).

[0013] Preferably, in step 1), the mass ratio of thermoplastic resin to epoxy resin is 1:5 to 1:20; and the molar ratio of curing agent to epoxy resin is 1:0.8 to 1.20.

[0014] Preferably, in step 1), the dissolution time of the thermoplastic resin and epoxy resin is 2 to 4 hours; the vacuum exhaust temperature is 90°C to 140°C and the time is 30 minutes to 1 hour; the sample curing time is 30 minutes to 3 hours.

[0015] Preferably, in step 2), the organic solvent is N,N-dimethylacetamide (DMAc).

[0016] Preferably, in step 2), the mass ratio of the modified epoxy resin to the organic solvent is 1:3 to 1:5.

[0017] Preferably, in step 3), the carbon fiber cloth CF can be unidirectional carbon fiber cloth or bidirectional carbon fiber cloth.

[0018] Preferably, in step 4), a certain mass of adhesive is weighed according to the preset load, and then the adhesive is evenly brushed onto the fiber cloth with a brush. The carbon fiber cloth is checked to see if it is soaked and if the amount of adhesive is uniform. The cloth is then heated at 120°C for 4 hours and at 140°C for 8 hours in an oven until N,N-dimethylacetamide (DMAc) is completely removed.

[0019] Preferably, in step 4), the prepreg is cut to a suitable size and laid in a certain layering sequence to obtain a preform. This preform is then placed in a steel mold. A release agent should be applied to the surface of the mold cavity. The amount of release agent should be as small as possible while still meeting the demolding requirements, and the application should be uniform. The laid-up prepreg is placed on a molding machine and initially pressurized at 120°C for 0.3–0.6 MPa and held at that temperature for 0.5–1 hour. Then, the pressure is fully increased to 3–5 MPa, and the prepreg is cured at 180°C for 2 hours.

[0020] Preferably, in step 4), the order and number of layers can be selected according to the design requirements, and the angle of each layer can be 0°, 45° or 90° from the previous layer.

[0021] Preferably, in step 4), to ensure the compactness of the final composite material, a vacuum is drawn once for every 30 layers of carbon fiber prepreg to ensure that the prepreg layer is flat and free of air bubbles, with a vacuum pressure of not less than -0.09 MPa and a pressure holding time of 30 minutes.

[0022] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0023] 1. This invention is a high-toughness carbon fiber reinforced resin-based impact-resistant composite board. Through oxidation treatment of fiber cloth and toughening modification of epoxy resin, a high-toughness carbon fiber reinforced resin-based composite board is finally prepared, thereby improving the elasticity of the composite board.

[0024] 2. A simple method for preparing high-toughness carbon fiber reinforced resin-based impact-resistant composite plates is provided. Detailed Implementation

[0025] The following examples illustrate the implementation of this invention in detail, but they do not constitute a limitation on the invention and are merely illustrative. Furthermore, explaining the advantages of this invention will make it clearer and easier to understand. Unless otherwise specified, the experimental methods used in this invention are conventional methods, and the experimental equipment, materials, reagents, etc., used are all commercially available.

[0026] Example 1:

[0027] Preparation of high-toughness carbon fiber reinforced resin-based impact-resistant composite plate:

[0028] (1) Preparation of modified epoxy resin: 5g of thermoplastic resin powder PEK was dissolved in 45g of epoxy resin monomer (TGDDM) at 140℃ at a mass ratio of 10% for 4h; the above sample was placed in a vacuum oven for degassing at 90℃ for 2h; 4,4′-DDS and TGDDM were added to the above blend at 120℃ at a molar ratio of 1:1 until the mixture was stirred evenly; the above sample was placed in an oven and heated to 180℃ at a rate of 1℃ / min until it reached a stable state, and then kept at 180℃ for 30min to achieve complete curing of the resin.

[0029] (2) Preparation of adhesive solution: In order to adjust the viscosity of the adhesive solution, weigh 20g of cured modified epoxy resin, grind it thoroughly, add it to 100g of DMAc medium, heat it to 60℃ to dissolve it, and stir it evenly to prepare the resin adhesive solution.

[0030] (3) Carbon fiber cloth treatment: Soak the carbon fiber cloth in acetone at room temperature for 10 hours to remove surface impurities, and then keep it at 110°C for 1 hour in a vacuum chamber; then place the carbon fiber cloth into an inductively coupled plasma reactor (the system includes at least one vacuum chamber, one mass flow controller, a maximum operating pressure of 100 Pa, and a maximum power of 1000 W); oxygen is fed into the vacuum chamber at a flow rate of 5 standard state cubic centimeters per minute, the operating pressure is set to 20 Pa, and each is treated with oxygen plasma with a power of 300 W for 5 minutes.

[0031] (4) Select carbon fiber unidirectional cloth as reinforcement. Weigh the resin solution according to the mass ratio of resin solution to carbon fiber cloth of 30:70. Brush the resin solution evenly onto the fiber cloth with a brush until the fiber cloth is soaked and the resin solution is evenly distributed on the fiber cloth. Then heat it in an oven at 120℃ for 4 hours and at 140℃ for 8 hours until N,N-dimethylacetamide (DMAc) is completely removed.

[0032] (5) Cut the prepared single-piece fiber cloth coated with adhesive into 30cm×30cm pieces, according to [0 / 45 / 0 / 45 / 90]. s The preform is obtained by laying out the layers in sequence and placed in a steel mold. A release agent should be applied to the surface of the mold cavity. The amount of release agent should be as small as possible while meeting the demolding requirements, and the application should be uniform. The laid-up prepreg is placed on a molding machine and initially pressurized at 0.5 MPa at 120°C for 1 hour; then fully pressurized to 4 MPa and cured at 180°C for 2 hours.

[0033] (6) After the mold cools to 40°C, demold.

[0034] (7) Impact tests were conducted on the composite board prepared above and the conventional carbon fiber reinforced epoxy resin composite board. The results showed that the impact strength of the untreated carbon fiber reinforced unmodified epoxy resin composite board was 207 KJ / m. 2 The impact strength of the composite plate obtained by this invention is 311 KJ / m. 2 The impact strength is increased by 50.2%, and the composite plate prepared by this invention has better impact resistance.

[0035] The above are merely specific embodiments of the present invention. It should be noted that any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the protection scope of the present invention. Any other aspects not described in detail are prior art.

Claims

1. A method of making a high-toughness carbon fiber reinforced resin-based impact-resistant composite panel, characterized by: The specific process is as follows: 1) Preparation of modified epoxy resin: Thermoplastic resin powder is dissolved in epoxy resin monomer at 140℃ for a certain period of time until no obvious powder remains; it is placed in a vacuum oven for degassing until all air bubbles are eliminated; the curing agent 4,4-diaminodiphenyl sulfone is added at 120℃ and stirred until homogeneous; it is placed in an oven, and the temperature is increased to 180℃ at a rate of 1℃ / min until it reaches a stable state, and then maintained at 180℃ to achieve complete resin curing; the mass ratio of thermoplastic resin to epoxy resin is 1:5~1:20; the curing agent and... The molar ratio of epoxy resin is 1:0.8~1.20; the dissolution time of thermoplastic resin and epoxy resin is 2~4h; the vacuum exhaust temperature is 90℃~140℃, and the time is 30min~1h; the sample curing time is 30min~3h; the epoxy resin is 4,4-diaminodiphenylmethane tetraglycidylamine (TGDDM) high-temperature resistant epoxy resin and N,N,O-triglycidyl-p-aminophenol (TGAP) trifunctional epoxy resin suitable for high-temperature curing in liquid molding. 2) Preparation of modified epoxy resin solution: Grind the cured modified epoxy resin into powder, and then add it to an organic solvent in a certain mass ratio to prepare the modified epoxy resin solution. 3) Carbon fiber cloth treatment: The carbon fiber cloth is soaked in acetone at room temperature for 6-24 hours to remove surface impurities, and then kept at 90-110℃ in a vacuum chamber for 0.5-3 hours; then the carbon fiber cloth is placed in an inductively coupled plasma reactor, which includes at least one vacuum chamber, one mass flow controller, a maximum operating pressure of 100 Pa, and a maximum power of 1000 W; oxygen is introduced into the vacuum chamber at a flow rate of 2-7 standard state cubic centimeters per minute, the operating pressure is set to 5-50 Pa, and the cloth is treated with oxygen plasma with a power of 200-700 W for 1-10 minutes; the carbon fiber cloth is multi-layered, and the angle of each layer is 0°, 45°, or 90° relative to the previous layer. 4) Preparation of prepreg: The carbon fiber cloth is impregnated with adhesive by coating method, and the organic solvent is removed by heating and drying to obtain prepreg; the prepreg is stacked and hot-pressed and cured in a molding machine according to the optimized hot pressing process; after the mold cools down to below 40°C, the composite board is demolded to obtain carbon fiber reinforced modified epoxy resin composite board.

2. The method for preparing the high-toughness carbon fiber reinforced resin-based impact-resistant composite plate according to claim 1, characterized in that: In step (2), the mass ratio of the modified epoxy resin to the organic solvent is 1:3 to 1:5, and the organic solvent used is N,N-dimethylacetamide (DMAc).

3. The method for preparing the high-toughness carbon fiber reinforced resin-based impact-resistant composite plate according to claim 1, characterized in that... In step (4), according to the pre-set load, a certain mass of adhesive is weighed, and then the adhesive is evenly brushed onto the fiber cloth with a brush. The carbon fiber cloth is checked to see if it is soaked and if the amount of adhesive is uniform. The cloth is heated at 120°C for 4 hours and at 140°C for 8 hours in an oven until N,N-dimethylacetamide is completely removed.

4. The method for preparing the high-toughness carbon fiber reinforced resin-based impact-resistant composite plate according to claim 1, characterized in that: In step (4), the prepreg is cut into appropriate sizes and laid in a certain layering sequence to obtain a preform. It is placed in a steel mold and a release agent is applied to the surface of the mold cavity. The amount of release agent should be as small as possible while meeting the demolding requirements. The application should be uniform. The prepreg is placed on a molding press and initially pressurized at 120°C for 0.3~0.6MPa and kept warm for 0.5~1h. Then, it is fully pressurized to 3~5MPa and cured at 180°C for 2h.

5. The method for preparing the high-toughness carbon fiber reinforced resin-based impact-resistant composite plate according to claim 1, characterized in that: In step (4), in order to ensure the compactness of the final composite material, a vacuum is drawn once for every 30 layers of carbon fiber prepreg to ensure that the prepreg layer is flat and free of air bubbles. The vacuum pressure is not less than -0.09MPa and is maintained for 30 minutes.