1. A preparation method of a carbon fiber reinforced high-strength and high-heat-conductivity composite film is characterized by comprising the following steps: the method comprises the following steps:

(1) pouring a solvent into a reaction kettle, adding a diamine monomer, stirring until the diamine monomer is completely dissolved, adding a dianhydride monomer, stirring at 0-25 ℃ until the dianhydride monomer is fully reacted, and finally adding graphene and stirring until the graphene is uniformly dispersed to obtain a polyamic acid solution containing the graphene; diamine monomer (b): dianhydride monomer in a molar ratio of 1: 0.7-1.2;

(2) soaking the polyamic acid solution containing graphene prepared in the step (1) in continuous carbon fiber cloth, and then curing under the protection of nitrogen to prepare a heat-conducting film precursor;

(3) and (3) carbonizing and graphitizing the precursor of the heat-conducting film prepared in the step (2) at the temperature of 800-2000 ℃ under the protection of nitrogen to prepare the carbon fiber reinforced high-strength and high-heat-conducting composite film.

2. The method for preparing the carbon fiber reinforced high-strength high-thermal-conductivity composite film according to claim 1, wherein the method comprises the following steps: in the step (1), the solvent is N, N' -Dimethylacetamide (DMAC) and/or N, N-dimethylformamide.

3. The method for preparing a carbon fiber reinforced high-strength high-thermal-conductivity composite film according to claim 1, wherein the diamine monomer in the step (1) is any one or a mixture of two or three of 4, 4' -diaminodiphenyl ether, diphenyl ether diamine and m-phenylenediamine in any ratio.

4. The method for preparing the carbon fiber reinforced high-strength high-thermal-conductivity composite film according to claim 1, wherein the method comprises the following steps: the dianhydride monomer in the step (1) is one or a mixture of two or three of pyromellitic dianhydride, biphenyl tetracarboxylic dianhydride and ketone anhydride in any proportion.

5. The method for preparing the carbon fiber reinforced high-strength high-thermal-conductivity composite film according to claim 1, wherein the method comprises the following steps: in the step (2), the specification of the carbon fiber cloth is 160-300 g/m²。

6. The method for preparing the carbon fiber reinforced high-strength high-thermal-conductivity composite film according to claim 1, wherein the method comprises the following steps: the mass ratio of the graphene to the diamine monomer in the step (1) is as follows: 1-50: 100.

7. the method for preparing the carbon fiber reinforced high-strength high-thermal-conductivity composite film according to claim 1, wherein the method comprises the following steps: the stirring time at the temperature of 0-25 ℃ in the step (1) is at least 10 h.

Background

With the rapid development of communication, electronics, aerospace and national defense war industry, the integration degree and power density of electronic components are continuously improved, and the dissipation power density and heat productivity of the components are larger and larger. For long-term operation of aircraft such as spaceships, the service life and safety of the aircraft are greatly reduced due to the heat accumulation on the surface of the aircraft. Therefore, the application of the heat conducting and radiating material is more and more extensive, and the requirement on the heat conducting efficiency is higher and higher. The mainstream heat conducting materials in the market still mainly comprise aluminum and copper metals or alloys, and in recent years, graphite heat conducting films are widely used and occupy certain market share. The graphite heat-conducting film has the unique advantages that: the first thermal conductivity coefficient is higher than 300-; the second density is small, the weight is light, and the weight is 25% lighter than that of aluminum and copper; 75% of light; and thirdly, the processing and the use are convenient. At present, the preparation methods of the graphite heat-conducting film comprise two methods: the membrane is prepared by rolling natural graphite serving as a raw material through a roller to a roller, and the method is simple, but the natural graphite has low thermal conductivity coefficient due to factors such as poor orientation, impurity and the like, and is generally 300-. In another method, a high molecular material is used as a precursor to carry out high-temperature carbonization and graphitization, the thermal conductivity of the material prepared by the method is higher than 800-1500 w/m.k, but the material prepared by the method has low strength and is easy to damage. When a pure polyimide film is carbonized and graphitized in the conventional high-thermal-conductivity film, non-carbon atoms of an aromatic chain are decomposed and released in a gas form, so that the structure is contracted to generate certain internal stress, and further an amorphous glassy carbon material is formed, and is fragile and easy to break. At present, the method of pre-stretching or applying positive pressure and the like is mainly adopted to eliminate the internal stress, and the problem of shrinkage of the film in the carbonization process is solved. But this places more stringent requirements on the equipment and increases the process complexity in the manufacturing process.

Disclosure of Invention

In order to solve the technical defects that the high-thermal-conductivity graphite heat-conducting film in the prior art is low in mechanical strength, easy to damage and the like, the invention provides a preparation method of a carbon fiber reinforced high-strength and high-thermal-conductivity composite film.

In order to realize the purpose of the invention, the adopted technical scheme is as follows:

a preparation method of a carbon fiber reinforced high-strength and high-heat-conductivity composite film comprises the following steps:

(1) pouring a solvent into a reaction kettle, adding a diamine monomer, stirring until the diamine monomer is completely dissolved, adding a dianhydride monomer, stirring at 0-25 ℃ until the dianhydride monomer is fully reacted (generally for at least 10 hours), and finally adding graphene and stirring until the graphene-containing polyamic acid solution is uniformly dispersed to obtain a polyamic acid solution containing the graphene; diamine monomer (b): dianhydride monomer in a molar ratio of 1: 0.7-1.2;

(2) soaking the polyamic acid solution containing graphene prepared in the step (1) in continuous carbon fiber cloth, and then curing under the protection of nitrogen to prepare a heat-conducting film precursor;

(3) and (3) carbonizing and graphitizing the precursor of the heat-conducting film prepared in the step (2) at the temperature of 800-2000 ℃ under the protection of nitrogen to prepare the carbon fiber reinforced high-strength and high-heat-conducting composite film.

Preferably, the specification of the carbon fiber cloth in the step (2) is 160-300 g/m²。

Preferably, the solvent in step (1) is N, N' -Dimethylacetamide (DMAC) and/or N, N-dimethylformamide.

Preferably, the diamine monomer in step (1) is any one or a mixture of two or three of 4, 4' -diaminodiphenyl ether, diphenyl ether diamine and m-phenylenediamine in any proportion.

Preferably, the dianhydride monomer in step (1) is one or a mixture of two or three of pyromellitic anhydride, biphenyl tetracarboxylic dianhydride and ketone anhydride in any proportion.

Preferably, the mass ratio of the graphene to the diamine monomer in the step (1) is: 1-50: 100.

compared with the prior art, the application has the following beneficial effects:

(1) according to the invention, the composite material with high thermal conductivity and excellent mechanical property is prepared by using continuous carbon fiber cloth and graphene reinforced polyimide and then carbonizing and graphitizing;

(2) the carbon fiber is prepared from organic fiber which has high carbon content and is not melted in the heat treatment process through processes of heat stabilization oxidation treatment, carbonization treatment, graphitization and the like. The carbon content of the carbon fiber is more than 90 percent, the carbon fiber has heat conduction and electric conduction performance, and more importantly, the carbon fiber has excellent mechanical property, and the tensile strength of the carbon fiber is more than 3500Mpa and can reach 5.5 GPa; the tensile strength of the glass fiber is 1000-2000MPa, and the glass fiber has high tensile strength and small elongation. Carbon fibers all have a greater tensile strength than steel, but their density is only 1/4 for steel. According to the invention, the carbon fiber cloth is firstly dipped in the graphene-containing polyamic acid solution and solidified to obtain the heat-conducting film precursor, the continuous fibers of the carbon fiber cloth have a reinforcing effect on polyimide in the heat-conducting film precursor, so that the heat-conducting film can be effectively prevented from shrinking and internal stress is reduced when the polyimide film is carbonized and graphitized, the carbonized material structure is regularly oriented, and the heat-conducting film has higher strength due to the reinforcing effect.

(3) Graphene not only has ultrahigh thermal conductivity but also has very good mechanical strength, and in addition, intensive intermolecular crosslinking is generated by the strong interaction (pi-pi action) of graphene molecules and polyimide molecules, and the large-area hexagonal layered structure of graphene aggravates electron conjugation. And polyimide generates a three-dimensional graphitized structure growing in the normal direction of the graphene plane along the graphene surface due to the pi-pi overlapping effect among molecules. Therefore, due to the induction of graphene, polyimide molecules are highly oriented after graphitization, thereby improving thermal conductivity and tensile strength.

The graphene can effectively promote the grain formation and the nucleation of the polyimide, so that the orderliness of the crystal orientation structure of the polyimide is increased. The graphene is influenced by the distribution and the integral orientation of the graphene in the polyimide, and has good regularity. The in-plane direction of the film can form larger crystallinity, in addition, graphene has a perfect two-dimensional structure, and can cooperate with carbon fiber cloth to generate a plane induction effect on polyimide, so that the polyimide has a remarkable orientation effect on the surface of the graphene, the problem of internal stress generated in polyimide carbonization is solved, the fracture toughness of a carbonized product is improved, the thermal stability of the film can be improved, and the mechanical property is directionally enhanced.

Detailed Description

The present invention is not limited to the following embodiments, and those skilled in the art can implement the present invention in other embodiments according to the disclosure of the present invention, or make simple changes or modifications on the design structure and idea of the present invention, and fall into the protection scope of the present invention. It should be noted that the embodiments and features of the embodiments may be combined with each other without conflict.

The invention is described in more detail below with reference to the following examples:

example 1

A preparation method of a carbon fiber reinforced high-strength and high-heat-conductivity composite film comprises the following steps:

(1) preparation of polyamic acid solution containing graphene:

into the reaction kettle was poured 1L of N, N' -Dimethylacetamide (DMAC) solvent in a 1: weighing 4, 4 '-diaminodiphenyl ether 100g in the monomer molar ratio of 1(4, 4' -diaminodiphenyl ether: pyromellitic dianhydride), pouring into a reaction kettle, and stirring for 5min until the monomers are completely dissolved; then weighing pyromellitic anhydride according to a proportion, adding the pyromellitic anhydride into a reaction kettle, and stirring for 10 hours at the temperature of 25 ℃; then 5g of graphene is added, and the mixture is stirred for 3 hours to obtain the polyamic acid solution containing the graphene.

(2) Preparing a heat-conducting film precursor:

using carbon fiber cloth (160 g/m)²) And (2) soaking the polyamic acid solution containing graphene obtained in the step (1), and curing at 400 ℃ under the protection of nitrogen to obtain a heat-conducting film precursor.

(3) Preparing a heat-conducting film:

and (3) carbonizing and graphitizing the precursor of the heat-conducting film obtained in the step (2) at 1500 ℃ under the protection of nitrogen to obtain the heat-conducting film, namely the carbon fiber reinforced high-strength and high-heat-conducting composite film.

The thermal conductivity coefficient of the thermal conductive film prepared in this embodiment is 1121W/mk, the mechanical tensile strength is 465Mpa, the dimensional shrinkage of the thermal conductive film after the treatment of step (3) is 0.53%, and the carbon fiber cloth (160 g/m)²) The tensile strength is 3500 MPa.

Example 2

A preparation method of a carbon fiber reinforced high-strength and high-heat-conductivity composite film comprises the following steps:

(1) preparation of polyamic acid solution containing graphene:

into the reaction kettle was poured 1.5L of N, N' -Dimethylacetamide (DMAC) solvent in a 1: weighing 4, 4 '-diaminodiphenyl ether 100g in monomer molar ratio of 1(4, 4' -diaminodiphenyl ether: pyromellitic dianhydride), pouring into a reaction kettle, stirring for 5min until the monomers are completely dissolved, weighing pyromellitic dianhydride in proportion, adding into the reaction kettle, stirring for 10h at 25 ℃, then adding 5g of graphene, and stirring for 3h to obtain the polyamic acid solution containing the graphene.

(2) Preparing a heat-conducting film precursor:

using carbon fiber cloth (200 g/m)²) And (2) soaking the polyamic acid solution containing graphene obtained in the step (1), and curing at 400 ℃ under the protection of nitrogen to obtain a heat-conducting film precursor.

(3) Preparing a heat-conducting film:

and (3) carbonizing and graphitizing the precursor of the heat-conducting film obtained in the step (2) at 1500 ℃ under the protection of nitrogen to prepare the heat-conducting film.

The thermal conductivity of the thermal conductive film prepared in this example is 1000W/mk, the mechanical tensile strength is 625MPa, the dimensional shrinkage of the thermal conductive film after the treatment in step (3) is 0.22%, and the carbon fiber cloth is 200g/m²) The tensile strength is 4900MPa

Example 3

A preparation method of a carbon fiber reinforced high-strength and high-heat-conductivity composite film comprises the following steps:

(1) preparation of polyamic acid solution containing graphene:

into the reaction kettle was poured 1L of N, N' -Dimethylacetamide (DMAC) solvent in a 1: weighing 4, 4 '-diaminodiphenyl ether 100g in monomer molar ratio of 1(4, 4' -diaminodiphenyl ether: pyromellitic dianhydride), pouring into a reaction kettle, stirring for 5min until the monomers are completely dissolved, weighing pyromellitic dianhydride in proportion, adding into the reaction kettle, stirring for 10h at 25 ℃, then adding 5g of graphene, and stirring for 3h to obtain the polyamic acid solution containing the graphene.

(2) Preparing a heat-conducting film precursor:

using carbon fiber cloth (300 g/m)²) And (2) soaking the polyamic acid solution containing graphene obtained in the step (1), and curing at 400 ℃ under the protection of nitrogen to obtain a heat-conducting film precursor.

(3) Preparing a heat-conducting film:

and (3) carbonizing and graphitizing the precursor of the heat-conducting film obtained in the step (2) at 1500 ℃ under the protection of nitrogen to prepare the heat-conducting film.

The thermal conductivity coefficient of the thermal conductive film prepared in the embodiment is 906W/mk, the mechanical tensile strength is 9253MPa, the dimensional shrinkage of the thermal conductive film after the treatment of the step (3) is 0.12%, and the carbon fiber cloth (300 g/m)²) The tensile strength is 5500 MPa.

Example 4

A preparation method of a carbon fiber reinforced high-strength and high-heat-conductivity composite film comprises the following steps:

(1) preparation of polyamic acid solution containing graphene:

into the reaction kettle was poured 1L of N, N' -Dimethylacetamide (DMAC) solvent in a 1:0.7 (4, 4 '-diaminodiphenyl ether: pyromellitic anhydride) 100g of 4, 4' -diaminodiphenyl ether was weighed in the molar ratio of the monomers and poured into a reaction vessel and stirred for 5min until the monomers were completely dissolved. And then weighing pyromellitic dianhydride in proportion, adding the pyromellitic dianhydride into the reaction kettle, and stirring the mixture for 10 hours at the temperature of 25 ℃. And adding 5g of graphene, and stirring for 3 hours to obtain the polyamic acid solution containing the graphene.

(2) Preparing a heat-conducting film precursor:

using carbon fiber cloth (160 g/m)²) And (2) soaking the polyamic acid solution containing graphene obtained in the step (1), and curing at 400 ℃ under the protection of nitrogen to obtain a heat-conducting film precursor.

(3) Preparing a heat-conducting film:

and (3) carbonizing and graphitizing the precursor of the heat-conducting film obtained in the step (2) at 1500 ℃ under the protection of nitrogen to prepare the heat-conducting film.

The thermal conductivity coefficient of the thermal conductive film prepared in the embodiment is 835W/mk, the mechanical tensile strength is 506MPa, the dimensional shrinkage of the thermal conductive film after the treatment of the step (3) is 0.76%,

carbon fiber cloth (160 g/m)²) The tensile strength is 3500 MPa.

Example 5

A preparation method of a carbon fiber reinforced high-strength and high-heat-conductivity composite film comprises the following steps:

(1) preparation of polyamic acid solution containing graphene:

into the reaction kettle was poured 1L of N, N' -Dimethylacetamide (DMAC) solvent in a 1: 1.2 molar ratio of monomer of diphenyl ether diamine: biphenyl tetracarboxylic dianhydride 100g of diphenyl ether diamine was weighed and poured into a reaction vessel and stirred for 5min until the monomer was completely dissolved. And then weighing pyromellitic dianhydride in proportion, adding the pyromellitic dianhydride into the reaction kettle, and stirring the mixture for 10 hours at the temperature of 25 ℃. And adding 5g of graphene, and stirring for 3 hours to obtain the polyamic acid solution containing the graphene.

(2) Preparing a heat-conducting film precursor:

using carbon fiber cloth (160 g/m)²) And (2) soaking the polyamic acid solution containing graphene obtained in the step (1), and curing at 400 ℃ under the protection of nitrogen to obtain a heat-conducting film precursor.

(3) Preparing a heat-conducting film:

carbonizing and graphitizing the precursor of the heat-conducting film obtained in the step (2) at 1500 ℃ under the protection of nitrogen to prepare the heat-conducting film.

The thermal conductivity of the thermal conductive film prepared in this example was 831W/mk, the mechanical tensile strength was 531MPa, the dimensional shrinkage of the thermal conductive film after the treatment in step (3) was 0.60%, and the carbon fiber cloth (160 g/m)²) Tensile strength is 3500MPa

Example 6

A preparation method of a carbon fiber reinforced high-strength and high-heat-conductivity composite film comprises the following steps:

(1) preparation of polyamic acid solution containing graphene:

into the reaction kettle was poured 1L of N, N' -Dimethylacetamide (DMAC) solvent in a 1: 1(4, 4 '-diaminodiphenyl ether: pyromellitic anhydride) was weighed 100g of 4, 4' -diaminodiphenyl ether in a molar ratio, poured into a reaction vessel, and stirred for 5min until the monomers were completely dissolved. And weighing pyromellitic dianhydride according to a proportion, adding the pyromellitic dianhydride into the reaction kettle, stirring for 10 hours at the temperature of 25 ℃, adding 5g of graphene, and stirring for 3 hours to obtain the polyamide acid solution containing the graphene.

(2) Preparing a heat-conducting film precursor:

using carbon fiber cloth (200 g/m)²) And (2) soaking the polyamic acid solution containing graphene obtained in the step (1), and curing at 400 ℃ under the protection of nitrogen to obtain a heat-conducting film precursor.

(3) Preparing a heat-conducting film:

and (3) carbonizing and graphitizing the precursor of the heat-conducting film obtained in the step (2) at 800 ℃ under the protection of nitrogen to prepare the heat-conducting film.

The thermal conductivity coefficient of the thermal conductive film prepared in the embodiment is 845W/mk, the mechanical tensile strength is 630MPa, the dimensional shrinkage of the thermal conductive film after the treatment in the step (3) is 0.56%, and the carbon fiber cloth (200 g/m)²) The tensile strength was 4900 MPa.

Example 7

A preparation method of a carbon fiber reinforced high-strength and high-heat-conductivity composite film comprises the following steps:

(1) preparation of polyamic acid solution containing graphene:

into the reaction kettle was poured 1L of N, N' -Dimethylacetamide (DMAC) solvent in a 1: 1(4, 4 '-diaminodiphenyl ether: pyromellitic anhydride) was weighed 100g of 4, 4' -diaminodiphenyl ether in a molar ratio, poured into a reaction vessel, and stirred for 5min until the monomers were completely dissolved. And then weighing pyromellitic dianhydride according to the proportion, adding the pyromellitic dianhydride into the reaction kettle, and stirring for 10 hours. Then 5g of graphene is added, and the mixture is stirred for 3 hours to obtain the polyamic acid solution containing the graphene.

(2) Preparing a heat-conducting film precursor:

using carbon fiber cloth (200 g/m)²) And (2) soaking the polyamic acid solution containing graphene obtained in the step (1), and curing at 400 ℃ under the protection of nitrogen to obtain a heat-conducting film precursor.

(3) Preparing a heat-conducting film:

and (3) carbonizing and graphitizing the precursor of the heat-conducting film obtained in the step (2) at 1500 ℃ under the protection of nitrogen to prepare the heat-conducting film.

The heat conducting film prepared by the embodiment is a heat conducting systemThe number is 1060W/mk, the mechanical tensile strength is 636MPa, the dimensional shrinkage of the heat-conducting film after the treatment of the step (3) is 0.13 percent, and the carbon fiber cloth (200 g/m)²) The tensile strength was 4900 MPa.

Example 8

A preparation method of a carbon fiber reinforced high-strength and high-heat-conductivity composite film comprises the following steps:

(1) preparation of polyamic acid solution containing graphene:

into the reaction kettle was poured 1L of N, N' -Dimethylacetamide (DMAC) solvent in a 1: 1(4, 4 '-diaminodiphenyl ether: pyromellitic anhydride) was weighed 100g of 4, 4' -diaminodiphenyl ether in a molar ratio, poured into a reaction vessel, and stirred for 5min until the monomers were completely dissolved. And then weighing pyromellitic dianhydride in proportion, adding the pyromellitic dianhydride into the reaction kettle, and stirring the mixture for 10 hours at the temperature of 25 ℃. Then 5g of graphene is added, and the mixture is stirred for 3 hours to obtain the polyamic acid solution containing the graphene.

(2) Preparing a heat-conducting film precursor:

using carbon fiber cloth (200 g/m)²) And (2) soaking the polyamic acid solution containing graphene obtained in the step (1), and curing at 400 ℃ under the protection of nitrogen to obtain a heat-conducting film precursor.

(3) Preparing a heat-conducting film:

and (3) carbonizing and graphitizing the precursor of the heat-conducting film obtained in the step (2) at 2000 ℃ under the protection of nitrogen to prepare the heat-conducting film.

The thermal conductivity coefficient of the thermal conductive film prepared in the embodiment is 1033W/mk, the mechanical tensile strength is 599MPa, the dimensional shrinkage of the thermal conductive film after the treatment of the step (3) is 0.4%, and the carbon fiber cloth (200 g/m)²) The tensile strength was 4900 MPa.

Example 9

A preparation method of a carbon fiber reinforced high-strength and high-heat-conductivity composite film comprises the following steps:

(1) preparation of polyamic acid solution containing graphene:

into the reaction kettle was poured 1L of N, N' -Dimethylacetamide (DMAC) solvent in a 1: 1(4, 4 '-diaminodiphenyl ether: pyromellitic anhydride) was weighed 100g of 4, 4' -diaminodiphenyl ether in a molar ratio, poured into a reaction vessel, and stirred for 5min until the monomers were completely dissolved. And then weighing pyromellitic dianhydride in proportion, adding the pyromellitic dianhydride into the reaction kettle, and stirring the mixture for 10 hours at the temperature of 25 ℃. And adding 1g of graphene, and stirring for 3 hours to obtain the polyamic acid solution containing the graphene.

(2) Preparing a heat-conducting film precursor:

using carbon fiber cloth (300 g/m)²) And (2) soaking the polyamic acid solution containing graphene obtained in the step (1), and curing at 400 ℃ under the protection of nitrogen to obtain a heat-conducting film precursor.

(3) Preparing a heat-conducting film:

and (3) carbonizing and graphitizing the precursor of the heat-conducting film obtained in the step (2) at 2000 ℃ under the protection of nitrogen to prepare the heat-conducting film.

The thermal conductivity of the thermal conductive film prepared in the embodiment is 850W/mk, the mechanical tensile strength is 1126MPa, the dimensional shrinkage of the thermal conductive film after the treatment in the step (3) is 0.05%, and the carbon fiber cloth is 300g/m²) The tensile strength is 5500 MPa.

Example 10

A preparation method of a carbon fiber reinforced high-strength and high-heat-conductivity composite film comprises the following steps:

(1) preparation of polyamic acid solution containing graphene:

into the reaction kettle was poured 1L of N, N' -Dimethylacetamide (DMAC) solvent in a 1: 1(4, 4 '-diaminodiphenyl ether: pyromellitic anhydride) was weighed 100g of 4, 4' -diaminodiphenyl ether in a molar ratio, poured into a reaction vessel, and stirred for 5min until the monomers were completely dissolved. And then weighing pyromellitic dianhydride in proportion, adding the pyromellitic dianhydride into the reaction kettle, and stirring the mixture for 10 hours at the temperature of 25 ℃. Then adding 25g of graphene, and stirring for 3 hours to obtain the polyamic acid solution containing the graphene.

(2) Preparing a heat-conducting film precursor:

using carbon fiber cloth (300 g/m)²) And (2) soaking the polyamic acid solution containing graphene obtained in the step (1), and curing at 400 ℃ under the protection of nitrogen to obtain a heat-conducting film precursor.

(3) Preparing a heat-conducting film:

and (3) carbonizing and graphitizing the precursor of the heat-conducting film obtained in the step (2) at 2000 ℃ under the protection of nitrogen to prepare the heat-conducting film.

The thermal conductivity coefficient of the thermal conductive film prepared in the embodiment is 1360W/mk, the mechanical tensile strength is 1263MPa, the dimensional shrinkage of the thermal conductive film after the treatment of the step (3) is 0.06%, and the carbon fiber cloth (300 g/m)²) The tensile strength is 5500 MPa.

Example 11

A preparation method of a carbon fiber reinforced high-strength and high-heat-conductivity composite film comprises the following steps:

(1) preparation of polyamic acid solution containing graphene:

into the reaction kettle was poured 1L of N, N' -Dimethylacetamide (DMAC) solvent in a 1: 1(4, 4 '-diaminodiphenyl ether: pyromellitic anhydride) was weighed 100g of 4, 4' -diaminodiphenyl ether in a molar ratio, poured into a reaction vessel, and stirred for 5min until the monomers were completely dissolved. And then weighing pyromellitic dianhydride in proportion, adding the pyromellitic dianhydride into the reaction kettle, and stirring the mixture for 10 hours at the temperature of 25 ℃. Then adding 50g of graphene, and stirring for 3 hours to obtain the polyamic acid solution containing the graphene.

(2) Preparing a heat-conducting film precursor:

using carbon fiber cloth (300 g/m)²) And (2) soaking the polyamic acid solution containing graphene obtained in the step (1), and curing at 400 ℃ under the protection of nitrogen to obtain a heat-conducting film precursor.

(3) Preparing a heat-conducting film:

and (3) carbonizing and graphitizing the precursor of the heat-conducting film obtained in the step (2) at 2000 ℃ under the protection of nitrogen to prepare the heat-conducting film.

The thermal conductivity coefficient of the thermal conductive film prepared in the embodiment is 821/mk, the mechanical tensile strength is 1109MPa, the size shrinkage rate of the thermal conductive film after the treatment of the step (3) is 0.08%, and the carbon fiber cloth (300 g/m)²) The tensile strength is 5500 MPa.

Comparative example 1

The preparation method of the heat-conducting film comprises the following steps

(1) Preparation of polyamic acid solution containing graphene:

into the reaction kettle was poured 1L of N, N' -Dimethylacetamide (DMAC) solvent in a 1: 1(4, 4 '-diaminodiphenyl ether: pyromellitic anhydride) was weighed 100g of 4, 4' -diaminodiphenyl ether in a molar ratio, poured into a reaction vessel, and stirred for 5min until the monomers were completely dissolved. And then weighing pyromellitic dianhydride in proportion, adding the pyromellitic dianhydride into the reaction kettle, and stirring the mixture for 10 hours at the temperature of 25 ℃.

(2) Preparing a heat-conducting film precursor:

and (3) coating the polyamic acid solution on a graphite vessel with the square meter of 1, and curing at 400 ℃ under the protection of nitrogen to obtain the heat-conducting film precursor.

(3) Preparing a heat-conducting film:

and (3) carbonizing and graphitizing the precursor of the heat-conducting film prepared in the step (2) at 1500 ℃ under the protection of nitrogen to prepare the heat-conducting film.

The heat conduction membrane prepared by the comparative example has the heat conduction coefficient of 806W/mk, the mechanical tensile strength of 72MPa and the dimensional shrinkage of 10 percent.

The specific test results of the above examples and comparative examples are shown in the following table:

the above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art should be considered to be within the technical scope of the present invention, and the technical solutions and their concepts should be equivalent or changed within the technical scope of the present invention.