CN113897033B - graphene/SiCnw composite film modified carbon fiber composite material and preparation method thereof - Google Patents

Abstract

The invention belongs to the technical field of high-performance carbon fiber composite materials, and particularly relates to a graphene/SiCnw composite film modified carbon fiber composite material and a preparation method thereof. The composite material comprises a composite preform, and the composite preform is obtained by impregnating liquid resin and curing; the composite prefabricated body comprises a plurality of layers of carbon fiber cloth, and a graphene/SiCnw composite film is embedded between the plurality of layers of carbon fiber cloth; the graphene/SiCnw composite film is a self-supporting graphene/SiCnw composite film with SiCnw uniformly distributed between graphene sheets in an inserting way. The preparation method comprises the steps of dispersing graphene and SiCnw into an aqueous solution, preparing the graphene/SiCnw composite film through a filter membrane vacuum-assisted self-assembly process, embedding the composite film between fiber cloth to form a composite prefabricated body, and preparing the graphene/SiCnw composite film modified carbon fiber composite material through a vacuum infusion process. The thermal mechanical property, longitudinal heat conduction and electric conductivity of the carbon fiber composite material prepared by the invention are obviously improved.

Description

A kind of graphene/SiCnw composite film modified carbon fiber composite material and preparation method thereof

technical field

The invention belongs to the technical field of high-performance carbon fiber composite materials, and in particular relates to a graphene/SiCnw composite film modified carbon fiber composite material and a preparation method thereof.

Background technique

Carbon fiber reinforced resin matrix composites (CFRP) are widely used in aerospace, transportation, energy equipment, construction engineering, sports equipment and other fields due to their light weight and high strength. With the increasingly urgent requirements for lightweight materials in various fields, CFRP is considered to be an indispensable strategic material for national defense and national economic construction. CFRP has excellent mechanical, thermal and electrical properties in the transverse direction, but its performance in the longitudinal direction is much lower than that in the transverse direction. For example, the longitudinal thermal conductivity of CFRP is low, generally not exceeding 1 W/m. K, which limits the wide application of composite materials in engineering fields.

Graphene has excellent mechanical, thermal (5000 W/m K) and electrical (6000 S/cm) properties, and has a fracture toughness as high as 4-10.7 MPa m ^1/2 , and is regarded as the most ideal secondary material for composite materials. Dimensional modified fillers. At present, the industry has achieved low-cost and large-scale preparation of graphene nanosheets containing multi-layer graphene through the "top-down" method, paving the way for the large-scale application of graphene materials in the field of composite materials.

SiCnw has superior mechanical, thermal (~390 W/m K) and electrical properties and high physical and chemical stability, thermal conductivity, critical breakdown electric field, electron saturation mobility and other characteristics, and is suitable for high temperature and high frequency , high-power and high-density integrated electronic devices have great application potential. Compared with intertwined carbon nanotubes, the one-dimensional SiCnw with flat structure can be more easily dispersed into the resin matrix, and can prepare polymer-based nanocomposites with thermal conductivity.

The interlayer of CFRP composites has low thermal and electrical conductivity in the longitudinal direction due to the presence of the resin matrix. Therefore, introducing thermally and electrically conductive nanomaterials into the interlayer region of composite materials is an effective way to effectively improve the longitudinal thermal and electrical conductivity of CFRP, especially the composite use of nanomaterials has a more obvious modification effect than single nanomaterials. However, how to introduce uniformly distributed and dispersed nanomaterials into CFRP and effectively improve the performance of composite materials is a key technical problem that needs to be solved urgently.

Contents of the invention

The purpose of the present invention is to provide a graphene/SiCnw composite film modified carbon fiber composite material and a preparation method thereof for the current situation of poor longitudinal thermal conductivity and electrical conductivity of the carbon fiber composite laminate.

To achieve the above object, the present invention adopts the following technical solutions:

A graphene/SiCnw composite film modified carbon fiber composite material, including a composite preform, the composite preform is impregnated with a liquid resin and solidified to obtain the composite material; the composite preform includes multi-layer carbon fiber cloth, and the multi-layer A graphene/SiCnw composite film is embedded between layers of carbon fiber cloth; the graphene/SiCnw composite film is a self-supporting graphene/SiCnw composite film in which SiCnw is uniformly interspersed and distributed between graphene sheets.

Preferably, the content of SiCnw in the graphene/SiCnw composite film is 0.1-20 wt.%, and the thickness of the graphene/SiCnw composite film is 100-150 μm.

Preferably, the graphene is single-layer or multi-layer graphene, and its plane diameter is 0.5-50 μm.

Preferably, the SiCnw is β-type SiC with a diameter of 100-600 nm and a length of 20-100 μm.

Preferably, the liquid resin is a mixture of low-viscosity epoxy resin or unsaturated polyester resin and curing agent, and the viscosity of the resin is 800-1400 mPas.

The invention also discloses a method for preparing a graphene/SiCnw composite film modified carbon fiber composite material, comprising the following steps:

(1) Preparation of graphene/SiCnw mixed dispersion: add graphene and SiCnw to the dispersant solution respectively, and obtain graphene dispersion and SiCnw dispersion by ultrasonic treatment, and then add SiCnw dispersion to the graphene dispersion , high-speed shear homogenization treatment to prepare a graphene/SiCnw mixed dispersion;

(2) Preparation of graphene/SiCnw composite film: the graphene/SiCnw dispersion liquid is prepared through the microporous filter membrane vacuum-assisted self-assembly method to prepare graphene/SiCnw composite, and then the filter is frozen, freeze-dried and heat-treated Afterwards, a self-supporting graphene/SiCnw composite film is obtained;

(3) Preparation of modified carbon fiber composite material: the graphene/SiCnw composite film is embedded between the layers of carbon fiber cloth to obtain a composite preform, and the composite preform is impregnated with liquid resin by vacuum infusion process, and the composite preform is obtained after heating and pressurizing. Graphene/SiCnw composite film modified carbon fiber composites.

Preferably, in step (1), the dispersant is any one of polyvinyl alcohol, polyacrylamide, and polyelectrolyte dispersant; the concentration of the dispersant solution is 0.5-2 mg/ml; the The concentration of the graphene dispersion and the SiCnw dispersion is 0.5-5 mg/ml.

Preferably, in step (1), the conditions for the ultrasonic treatment are: ultrasonic treatment for 3-10 minutes at a power of 30-150 W; the conditions for the high-speed shear homogenization treatment are: the rotating speed is 8000-15000 rpm, and the processing time 5 to 10 minutes.

Preferably, in step (2), the freezing temperature is -18 ºC; the freeze-drying process is carried out in a freeze dryer for 24 to 36 hours; the heat treatment temperature is 150 to 450 ºC , the time is 1-2 hours.

Preferably, in step (3), the conditions of the vacuum infusion process are: 50 ºC, the vacuum degree is 0.01-0.1 MPa; the heating and pressurizing curing conditions: the pressure is 5-15 MPa, 70-90 ºC curing 1 ~2 hours, then heat up to 120~160ºC and cure for 2~3 hours.

Beneficial effect

A kind of graphene/SiCnw composite film modified carbon fiber composite material provided by the invention and preparation method thereof have the following advantages:

① The present invention prepares a self-supporting graphene/SiCnw composite film in which SiCnw is evenly interspersed and distributed between graphene sheets through a simple vacuum-assisted self-assembly process. Graphene and SiCnw are introduced into CFRP in the form of a prefabricated composite film , effectively avoiding the agglomeration problem of GnP and SiCnw.

② In the present invention, the graphene/SiCnw composite film is embedded between carbon fiber cloths to form a composite prefabricated body, and then the composite material is prepared through a vacuum infusion process, which avoids the increase in resin viscosity and the effect of reinforcing fibers on nanometer materials due to the addition of nanomaterials in the traditional method. The filtering effect of the filler solves the problem of uniform distribution and dispersion of nanomaterials.

③ The introduction of SiCnw effectively promotes the construction of the heat conduction network in the thickness direction of the composite material, which is beneficial to the conduction of phonons in the thickness direction. The carbon fiber composite material modified between the layers of the prepared graphene/SiCnw composite film has excellent thermomechanical properties, high longitudinal thermal conductivity and electrical conductivity, and can expand the application field of carbon fiber composite materials.

Detailed ways

Hereinafter, the present invention will be described in detail. Before proceeding with the description, it should be understood that the terms used in this specification and appended claims should not be construed as limited to ordinary and dictionary meanings, but should be best interpreted while allowing the inventor to properly define the terms On the basis of the principles of the present invention, explanations are made based on meanings and concepts corresponding to the technical aspects of the present invention. Accordingly, the descriptions set forth herein are preferred examples for illustrative purposes only and are not intended to limit the scope of the invention, so that it should be understood that other, etc. price or improvement.

The following examples are only listed as examples of embodiments of the present invention, and do not constitute any limitation to the present invention. Those skilled in the art can understand that modifications within the scope of not departing from the essence and design of the present invention all fall into the protection of the present invention. scope. Unless otherwise specified, the reagents and instruments used in the following examples are all commercially available products.

Example 1

Cut four pieces of carbon fiber cloth, lay them up to form a carbon fiber prefabricated body, and seal the prefabricated body in a vacuum bag system. Then weigh 100 g of bisphenol A epoxy resin LY1564 and 25 g of amine curing agent 22962, mix and stir, put them into a high-speed mixer, mix at 3000 rpm for 2 min, and then transfer to a vacuum oven at 65 ºC In the process, evacuate and defoam until no bubbles come out to obtain a uniformly mixed mixture of epoxy resin and curing agent. The mixture of epoxy resin and curing agent was impregnated into the carbon fiber preform by vacuum infusion process, and then cured on a hot press at 80 ºC for 1 h and 150 ºC for 2 h under a pressure of 5 MPa to obtain an unmodified carbon fiber composite Material.

The storage modulus of the unmodified carbon fiber composite at 35 ºC was determined to be 27.8GPa by dynamic thermomechanical analysis, and the longitudinal thermal conductivity and electrical conductivity at room temperature were found to be 0.765 W/m K and 2.5× 10 ^-3 S/cm.

Example 2

A certain amount of polyvinyl alcohol was weighed and dissolved in deionized water at 95 ºC to prepare an aqueous solution with a concentration of 1 mg/ml, then graphene was added to 400 ml of the above solution, and ultrasonic treatment was performed at 100 W for 5 min to obtain Concentration is the graphene dispersion liquid of 1mg/ml, process 5 min under 13800 rpm by high-speed shearing homogenizer, be prepared into the graphene dispersion liquid that disperses uniformly.

The graphene dispersion was self-assembled by the microporous membrane vacuum-assisted self-assembly method. After the assembly was completed, the filter was frozen in the refrigerator for 12 h, and then freeze-dried for 24 h. After drying, it was further dried in a muffle furnace. After heat treatment at 350 ºC, a self-supporting graphene film was finally obtained.

Cut four pieces of carbon fiber cloth, and prepare three pieces of graphene film. The carbon fiber cloth and graphene film are laid alternately to form a composite prefabricated body, and the composite prefabricated body is sealed in a vacuum bag system. Then weigh 100 g of bisphenol A epoxy resin LY1564 and 25 g of amine curing agent 22962, mix and stir, put them into a high-speed mixer, mix at 3000 rpm for 2 minutes, and then transfer to a vacuum oven at 65 ºC , vacuum defoaming until no bubbles emerge to obtain a homogeneously mixed mixture of epoxy resin and curing agent. The mixture of epoxy resin and curing agent was impregnated into the composite preform by vacuum infusion process, and then cured on a hot press at 80 ºC for 1 h at a pressure of 5 MPa, and then cured at 150 ºC for 2 h to obtain a graphene film interlayer. Modified carbon fiber composites.

The storage modulus of the carbon fiber composite material modified between graphene film layers was 41.0 GPa at 35 ºC by dynamic thermomechanical analysis, and the longitudinal thermal conductivity and electrical conductivity at room temperature were found to be 1.4 W/m· K and 1.7×10 ^-2 S/cm.

Compared with Example 1, the difference in Example 2 is that a graphene film is inserted between the layers of the composite material.

From this, it can be seen that the storage modulus, longitudinal thermal conductivity and electrical conductivity of the composite material in Example 2 are respectively increased by 47.5%, 85.6% and 560% compared with Example 1.

Example 3

A certain amount of polyvinyl alcohol was weighed and dissolved in deionized water at 95 ºC to prepare an aqueous solution with a concentration of 1 mg/ml, then graphene and SiCnw were added to 400 ml of the above solution, and ultrasonic treatment was performed at a power of 100 W. 5 min to obtain a concentration of 1 mg/ml graphene dispersion and SiCnw dispersion, then 10.26 ml SiCnw dispersion was added to the graphene dispersion, processed by a high-speed shear homogenizer at 13800 rpm for 5 min to prepare Uniformly dispersed graphene/SiCnw hybrid dispersion.

The graphene/SiCnw dispersion was assembled with graphene and SiCnw through the microporous membrane vacuum-assisted self-assembly method. After the assembly was completed, the filter was frozen in the refrigerator for 12 h, and then freeze-dried for 24 h. After drying, After further heat treatment at 350 ºC in a muffle furnace, a self-supporting graphene/SiCnw-2.5 wt.% composite film was finally obtained.

Four pieces of carbon fiber cloth were cut, and three pieces of graphene/SiCnw-2.5 wt.% composite film were prepared. The carbon fiber cloth and the composite film were laminated alternately to form a composite preform, and the composite preform was sealed in a vacuum bag system. Then weigh 100 g of bisphenol A epoxy resin LY1564 and 25 g of amine curing agent 22962, mix and stir, put them into a high-speed mixer, mix at 3000 rpm for 2 min, and then transfer to a vacuum oven at 65 ºC In the process, evacuate and defoam until no bubbles come out to obtain a uniformly mixed mixture of epoxy resin and curing agent. The mixture of epoxy resin and curing agent was impregnated into the composite preform by vacuum infusion process, and then cured on a hot press at 80 ºC for 1 h and 150 ºC for 2 h under a pressure of 5 MPa to obtain graphene/SiCnw-2.5 wt.% Composite thin film interlayer modified carbon fiber composites.

The storage modulus of the carbon fiber composite material modified between graphene film layers was 42.4 GPa at 35 ºC measured by dynamic thermomechanical analysis, and the longitudinal thermal conductivity and electrical conductivity at room temperature were found to be 1.8 W/m· K and 1.2×10 ^-2 S/cm.

Compared with Example 1, the difference in Example 3 is that a graphene/SiCnw-2.5wt.% composite film is inserted between the layers of the composite material.

From this, it can be seen that the storage modulus, longitudinal thermal conductivity and electrical conductivity of the composite material in Example 3 are respectively increased by 52.7%, 139.2% and 386.2% compared with Example 1.

Example 4

A certain amount of polyvinyl alcohol was weighed and dissolved in deionized water at 95 ºC to prepare an aqueous solution with a concentration of 1 mg/ml, then graphene and SiCnw were added to 400 ml of the above solution, and ultrasonic treatment was performed at a power of 100 W. 5 min to obtain a graphene dispersion and a SiCnw dispersion with a concentration of 1 mg/ml, then 21.1 ml of SiCnw dispersion was added to the graphene dispersion, and processed by a high-speed shear homogenizer at 13800 rpm for 5 min to prepare Uniformly dispersed graphene/SiCnw hybrid dispersion.

The graphene/SiCnw dispersion was assembled with graphene and SiCnw through the microporous membrane vacuum-assisted self-assembly method. After the assembly was completed, the filter was frozen in the refrigerator for 12 h, and then freeze-dried for 24 h. After drying, After further heat treatment at 350 ºC in a muffle furnace, a self-supporting graphene/SiCnw-5 wt.% composite film was finally obtained.

Four pieces of carbon fiber cloth were cut, and three pieces of graphene/SiCnw-5 wt.% composite film were prepared. Carbon fiber cloth and composite film were laminated alternately to form a composite preform, and the composite preform was sealed in a vacuum bag system. Then weigh 100 g of bisphenol A epoxy resin LY1564 and 25 g of amine curing agent 22962, mix and stir, put them into a high-speed mixer, mix at 3000 rpm for 2 min, and then transfer to a vacuum oven at 65 ºC In the process, evacuate and defoam until no bubbles come out to obtain a uniformly mixed mixture of epoxy resin and curing agent. The prepared mixture of epoxy resin and curing agent was impregnated into the composite preform by vacuum infusion process, and then cured at 80 °C for 1 h at a pressure of 5 MPa on a hot press, and then cured at 150 °C for 2 h to obtain graphene/ SiCnw-5 wt.% Composite film interlayer modified carbon fiber composites.

The storage modulus of the carbon fiber composite material modified between layers of graphene film is 44.3 GPa at 35 ºC measured by dynamic thermomechanical analysis, and the longitudinal thermal conductivity and electrical conductivity at room temperature are found to be 2.2 W/m· K and 9.9×10 ^-3 S/cm.

Compared with Example 1, the difference in Example 4 is that a graphene/SiCnw-5wt.% composite film is inserted between the layers of the composite material.

From this, it can be seen that the storage modulus, longitudinal thermal conductivity and electrical conductivity of the composite material in Example 4 are respectively increased by 52.7%, 186.3% and 291.3% compared with Example 1.

Example 5

A certain amount of polyvinyl alcohol was weighed and dissolved in deionized water at 95 ºC to prepare an aqueous solution with a concentration of 1 mg/ml, then graphene and SiCnw were added to 400 ml of the above solution, and ultrasonic treatment was performed at a power of 100 W. 5 min to obtain a graphene dispersion and a SiCnw dispersion with a concentration of 1 mg/ml, then add 44.44 ml of SiCnw dispersion to the graphene dispersion, and process it at 13800 rpm for 5 min by a high-speed shear homogenizer to prepare Uniformly dispersed graphene/SiCnw hybrid dispersion.

The graphene/SiCnw dispersion was assembled with graphene and SiCnw through the microporous membrane vacuum-assisted self-assembly method. After the assembly was completed, the filter was frozen in the refrigerator for 12 h, and then freeze-dried for 24 h. After drying, After further heat treatment at 350 ºC in a muffle furnace, a self-supporting graphene/SiCnw-10 wt.% composite film was finally obtained.

Four pieces of carbon fiber cloth were cut, and three pieces of graphene/SiCnw-10 wt.% composite film were prepared. Carbon fiber cloth and composite film were laminated alternately to form a composite preform, and the composite preform was sealed in a vacuum bag system. Then weigh 100 g of bisphenol A epoxy resin LY1564 and 25 g of amine curing agent 22962, mix and stir, put them into a high-speed mixer, mix for 2 min at 3000 rpm, and then transfer to 65 ° C for vacuum drying In the box, evacuate and defoam until no bubbles come out to obtain a uniformly mixed mixture of epoxy resin and curing agent. The prepared mixture of epoxy resin and curing agent was impregnated into the composite preform by vacuum infusion process, and then cured on a hot press at 80 °C for 1 h and 150 °C for 2 h under a pressure of 5 MPa to obtain graphene/SiCnw -10 wt.% Carbon fiber composites modified between composite film layers.

The storage modulus of the carbon fiber composite material modified between the graphene film layers was 47.1 GPa at 35 ºC measured by dynamic thermomechanical analysis, and the longitudinal thermal conductivity and electrical conductivity at room temperature were found to be 1.9 W/m· K and 8.9×10 ^-3 S/cm.

Compared with Example 1, the difference in Example 5 is that a graphene/SiCnw-10wt.% composite film is inserted between the layers of the composite material.

From this, it can be seen that the storage modulus, longitudinal thermal conductivity and electrical conductivity of the composite material in Example 5 are respectively increased by 69.5%, 147.1% and 251.8% compared with Example 1.

From the above examples, it can be known that the introduction of graphene film into the interlayer region of CFRP as a reinforcing modified material can significantly improve the storage modulus, longitudinal thermal conductivity and longitudinal electrical conductivity of the composite material. When the graphene/SiCnw composite film is used as the modified material, the storage modulus and longitudinal thermal conductivity of the CFRP composite can be further improved. However, when the content of SiCnw in the graphene/SiCnw composite film is too high, a large number of graphene-SiCnw contact interfaces will be generated in the composite material, which will increase the interface contact thermal resistance and affect the transmission of phonons in the material. Therefore, reasonable control of the SiCnw content in the graphene/SiCnw composite film can endow CFRP with high thermomechanical properties and longitudinal thermal conductivity, while maintaining high longitudinal conductivity.

The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art can still understand the foregoing embodiments. Modifications are made to the technical solutions described, or equivalent replacements are made to some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions claimed in the present invention.

Claims (10)

1. a graphene/SiCnw composite film modified carbon fiber composite material, is characterized in that: A composite preform is included, and the composite material is obtained after the composite preform is impregnated with a liquid resin and cured; The composite prefabricated body comprises a multi-layer carbon fiber cloth, and a graphene/SiCnw composite film is embedded between the multi-layer carbon fiber cloth; the graphene/SiCnw composite film is a self-supporting graphite in which SiCnw is uniformly interspersed and distributed between graphene sheets olefin/SiCnw composite film; The preparation method of the graphene/SiCnw composite film comprises the following steps: the graphene/SiCnw dispersion is prepared through a microporous filter membrane vacuum-assisted self-assembly method to prepare a graphene/SiCnw composite, and then the filter is frozen and freeze-dried Self-supporting graphene/SiCnw composite films were obtained after treatment and heat treatment. 2. Graphene/SiCnw composite film modified carbon fiber composite material according to claim 1, is characterized in that, the content of SiCnw in described Graphene/SiCnw composite film is 0.1～20 wt.%, described Graphene/SiCnw The thickness of the SiCnw composite film is 100-150 μm. 3. The graphene/SiCnw composite film modified carbon fiber composite material according to claim 1, wherein the graphene is single-layer or multi-layer graphene, and its plane diameter is 0.5-50 μm. 4. The graphene/SiCnw composite film modified carbon fiber composite material according to claim 1, wherein the SiCnw is a β-type SiC with a diameter of 100-600 nm and a length of 20-100 μm. 5. Graphene/SiCnw composite film modified carbon fiber composite material according to claim 1, is characterized in that, described liquid resin is the mixture of low-viscosity epoxy resin or unsaturated polyester resin and curing agent, and resin viscosity is 800～1400mPas. 6. Graphene/SiCnw composite film modified carbon fiber composite material according to claim 1, is characterized in that, in the preparation method of described Graphene/SiCnw composite film, the temperature of described freezing is-18 ºC; The drying treatment is carried out in a freeze dryer for 24-36 hours; the temperature of the heat treatment is 150-450ºC and the time is 1-2 hours. 7. the preparation method of the arbitrary described Graphene/SiCnw composite thin film modified carbon fiber composite material of claim 1-6, is characterized in that, comprises the following steps: (1) Preparation of graphene/SiCnw mixed dispersion: add graphene and SiCnw to the dispersant solution respectively, and obtain graphene dispersion and SiCnw dispersion by ultrasonic treatment, and then add SiCnw dispersion to the graphene dispersion , high-speed shear homogenization treatment to prepare a graphene/SiCnw mixed dispersion; (2) Preparation of graphene/SiCnw composite film; (3) Preparation of modified carbon fiber composite material: the graphene/SiCnw composite film is embedded between the layers of carbon fiber cloth to obtain a composite preform, and the composite preform is impregnated with liquid resin by vacuum infusion process, and the composite preform is obtained after heating and pressurizing. Graphene/SiCnw composite film modified carbon fiber composites. 8. The preparation method of graphene/SiCnw composite film modified carbon fiber composite material according to claim 7, characterized in that, in step (1), the dispersant is polyvinyl alcohol, polyacrylamide, polyelectrolyte Any one of the dispersants; the concentration of the dispersant solution is 0.5-2 mg/ml; the concentration of the graphene dispersion and SiCnw dispersion is 0.5-5 mg/ml. 9. The preparation method of graphene/SiCnw composite film modified carbon fiber composite material according to claim 7, characterized in that, in step (1), the condition of the ultrasonic treatment is: ultrasonic treatment 3 at a power of 30-150W ~10 minutes; the conditions for the high-speed shear homogenization treatment are: the rotation speed is 8000-15000 rpm, and the treatment time is 5-10 minutes. 10. The preparation method of graphene/SiCnw composite film modified carbon fiber composite material according to claim 7, characterized in that, in step (3), the conditions of the vacuum infusion process are: 50 ºC, vacuum degree 0.01 ～0.1MPa; the heating and pressurizing curing conditions: the pressure is 5～15MPa, curing at 70～90ºC for 1～2h, then heating up to 120～160ºC and curing for 2～3h.