Preparation method of graphene / carbon fiber / polymer composite material

Abstract

The invention discloses a preparation method of a graphene / carbon fiber / polymer composite material, and relates to the technical field of heat-conducting composites.Graphene and carbon fibers are subjected to surface modification, the compatibility of the graphene and the carbon fibers with a polymer is remarkably improved, uniform dispersion of the graphene and the carbon fibers in a polymer matrix is achieved, and the heat-conducting performance of the graphene / carbon fiber / polymer composite material is improved. Therefore, the graphene and the carbon fibers give full play to the heat conduction and enhancement effects, the heat conduction performance and the mechanical performance of the composite material are better improved, the application performance of the composite material is improved, and meanwhile the application field of the composite material is widened.

Description

Technical Field

[0001] The present invention relates to the technical field of thermally conductive composite materials, and in particular to a method for preparing a graphene / carbon fiber / polymer composite material. Background Art

[0002] In recent years, consumer electronics have become increasingly miniaturized, lightweight, and intelligent. The commercialization of 5G has driven investment in communication base station equipment, and the booming development of power batteries will significantly drive demand for and upgrade thermal conductive materials. For every 2°C increase in the operating temperature of electronic products, their reliability decreases by approximately 10%. Statistics show that 55% of electronic device failures are caused by temperatures exceeding the permitted limit. Therefore, achieving effective heat dissipation has become a bottleneck restricting the development of electronic devices.

[0003] Polymer materials are characterized by their lightweight, easy processing, corrosion resistance, and low cost. High-performance, multifunctional composite materials are essential strategic key new materials. Thermally conductive polymer composites for electronic and electrical applications are in high demand, but have long relied on imports. Therefore, the development of thermally conductive polymer composites with efficient thermal diffusion properties is crucial for further development in this field.

[0004] Thermally conductive composite materials are usually prepared by adding high thermal conductivity fillers to a resin matrix, where high thermal conductivity fillers play an important role in improving heat dissipation. Currently, the industrial preparation of thermal conductive materials still faces many problems:

[0005] (1) Most polymer composites typically exhibit low thermal conductivity (less than 0.5 W / mK), requiring high filler loadings (>50 wt%) when using traditional thermally conductive fillers. Therefore, how to achieve high thermal conductivity at low filling loadings has been a hot topic in the research of thermally conductive polymer composites in recent years.

[0006] (2) High filling significantly reduces the processability of the material, and the particles are prone to agglomeration and phase separation in the polymer matrix, forming stress concentration points and internal micro-defects, which seriously deteriorates the mechanical properties of the material. It is necessary to focus on breaking through the difficult problem of the inability to achieve both high strength and high thermal conductivity of composite materials used in current electronic devices. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to provide a method for preparing a graphene / carbon fiber / polymer composite material, by surface modification of graphene and carbon fiber, improving the compatibility of graphene and carbon fiber with the polymer, and achieving uniform dispersion of graphene and carbon fiber in the polymer matrix, so that the graphene and carbon fiber can fully exert their thermal conductivity and reinforcement effects.

[0008] The technical problem to be solved by the present invention is achieved by adopting the following technical solutions:

[0009] The present invention provides a method for preparing a graphene / carbon fiber / polymer composite material, comprising the following preparation steps:

[0010] (1) dispersing graphene in water, adding monomer, emulsifier and initiator to carry out copolymerization, filtering, washing with water, and drying to obtain modified graphene;

[0011] (2) dispersing carbon fibers in water, adding monomers, emulsifiers, and initiators to carry out copolymerization, filtering, washing, and drying to obtain modified carbon fibers;

[0012] (3) adding modified graphene and modified carbon fiber to the polymer and mixing them uniformly to obtain a premix;

[0013] (4) The premix is ​​added into a twin-screw extruder, melt-extruded, cooled and granulated to obtain a graphene / carbon fiber / polymer composite material.

[0014] Furthermore, the monomers include acrylate and vinyl-terminated dimethylmethylvinyl (siloxane and polysiloxane), wherein the mass ratio of acrylate to vinyl-terminated dimethylmethylvinyl (siloxane and polysiloxane) is (5-8):1. The molecular formula of vinyl-terminated dimethylmethylvinyl (siloxane and polysiloxane) is C 13 H 30 O3Si4, CAS number is 68083-18-1.

[0015] Furthermore, the acrylic acid ester includes but is not limited to one or more of methyl acrylate, ethyl acrylate, butyl acrylate, isobutyl acrylate, methyl methacrylate, ethyl methacrylate, hydroxyethyl methacrylate, and glycidyl methacrylate.

[0016] Furthermore, the initiator is a water-soluble initiator, and the amount used is 0.1 to 2% of the monomer mass.

[0017] Furthermore, the mass ratio of the graphene to the monomer is 1:(0.5-3).

[0018] Furthermore, the mass ratio of the carbon fiber to the monomer is 1:(0.5-3).

[0019] Furthermore, the emulsifier is a nonionic surfactant, and the amount used is 2 to 10% of the monomer mass.

[0020] Furthermore, the reaction temperature of the copolymerization reaction is 70-90° C., and the reaction time is 2-5 hours.

[0021] Furthermore, the polymer is one or more of polyester, polycarbonate, and polyesterimide.

[0022] Furthermore, the mass ratio of the polymer to the modified graphene and the modified carbon fiber is (80-90):(1-10):(1-10).

[0023] The beneficial effects of the present invention are as follows: the present invention performs surface modification on graphene and carbon fiber, significantly improves the compatibility of graphene and carbon fiber with polymers, and realizes uniform dispersion of graphene and carbon fiber in the polymer matrix, so that graphene and carbon fiber can give full play to their thermal conductivity and reinforcement effects, better improve the thermal conductivity and mechanical properties of the composite material, thereby enhancing the application performance of the composite material and at the same time broadening the application field of the composite material. DETAILED DESCRIPTION

[0024] In order to make the technical means, creative features, objectives and effects achieved by the present invention easier to understand, the present invention is further described below in conjunction with specific embodiments.

[0025] The raw materials in the following examples and comparative examples are described:

[0026] Graphene was purchased from Guangdong Yina Technology Co., Ltd., model AF666.

[0027] Carbon fiber was purchased from Jiangxi Shuobang New Material Technology Co., Ltd. 0.5 mm short chopped carbon fiber.

[0028] Vinyl-terminated dimethyl methyl vinyl (siloxane and polysiloxane) was purchased from Shanghai Mairui Biochemical Technology Co., Ltd.

[0029] Polyester was purchased from Guangzhou Rongyu Trading Co., Ltd., model VYLON GK888.

[0030] Polycarbonate was purchased from Dongguan Yuyang Plastic Materials Co., Ltd., model LG 1320C-07.

[0031] Example 1

[0032] (1) Graphene is dispersed in water, and monomer, emulsifier and initiator are added, copolymerized at 80°C for 3 hours, filtered, washed with water, and dried to obtain modified graphene. The mass ratio of graphene to monomer is 1:1, and the monomer is composed of methyl acrylate and vinyl-terminated dimethyl methyl vinyl (siloxane and polysiloxane) in a mass ratio of 5:1; the emulsifier is alkylphenol polyoxyethylene ether OP-10, and the amount used is 5% of the monomer mass; the initiator is ammonium persulfate, and the amount used is 0.5% of the monomer mass.

[0033] (2) Dispersing carbon fibers in water, adding monomers, emulsifiers, and initiators, copolymerizing at 80°C for 3 hours, filtering, washing, and drying to obtain modified carbon fibers. The mass ratio of carbon fibers to monomers is 1:2, and the monomers are composed of methyl acrylate and vinyl-terminated dimethyl methyl vinyl (siloxane and polysiloxane) in a mass ratio of 8:1. The emulsifier is alkylphenol polyoxyethylene ether OP-10, and the amount used is 10% of the monomer mass. The initiator is ammonium persulfate, and the amount used is 1% of the monomer mass.

[0034] (3) Adding modified graphene and modified carbon fiber to polyester in a mass ratio of 90:5:5, mixing them evenly, and obtaining a premix.

[0035] (4) The premix is ​​added to a twin-screw extruder (main engine speed is 30 Hz, feeder speed is 10 Hz, and operating temperature is 240-280° C.), melt-extruded, cooled and granulated to obtain a graphene / carbon fiber / polyester composite material.

[0036] Example 2

[0037] (1) Graphene is dispersed in water, and monomer, emulsifier and initiator are added, copolymerized at 90°C for 2 hours, filtered, washed with water, and dried to obtain modified graphene. The mass ratio of graphene to monomer is 1:0.5, and the monomer is composed of methyl methacrylate and vinyl-terminated dimethyl methyl vinyl (siloxane and polysiloxane) in a mass ratio of 6:1; the emulsifier is alkylphenol polyoxyethylene ether OP-10, and the amount used is 5% of the monomer mass; the initiator is potassium persulfate, and the amount used is 1% of the monomer mass.

[0038] (2) Dispersing carbon fibers in water, adding monomers, emulsifiers, and initiators, copolymerizing at 70°C for 5 hours, filtering, washing, and drying to obtain modified carbon fibers. The mass ratio of carbon fibers to monomers is 1:1, and the monomers are composed of methyl methacrylate and vinyl-terminated dimethyl methyl vinyl (siloxane and polysiloxane) in a mass ratio of 5:1. The emulsifier is alkylphenol polyoxyethylene ether OP-10, and the amount used is 10% of the monomer mass. The initiator is potassium persulfate, and the amount used is 2% of the monomer mass.

[0039] (3) Adding modified graphene and modified carbon fiber to polyester in a mass ratio of 85:10:5, mixing them evenly, and obtaining a premix.

[0040] (4) The premix is ​​added to a twin-screw extruder (main engine speed is 30 Hz, feeder speed is 10 Hz, and operating temperature is 240-280° C.), melt-extruded, cooled and granulated to obtain a graphene / carbon fiber / polyester composite material.

[0041] Example 3

[0042] (1) Graphene is dispersed in water, and monomer, emulsifier and initiator are added, copolymerized at 80°C for 4 hours, filtered, washed with water, and dried to obtain modified graphene. The mass ratio of graphene to monomer is 1:3, and the monomer is composed of hydroxyethyl methacrylate and vinyl-terminated dimethyl methyl vinyl (siloxane and polysiloxane) in a mass ratio of 5:1; the emulsifier is fatty alcohol polyoxyethylene ether AEO-9, the amount of which is 8% of the monomer mass; and the initiator is ammonium persulfate, the amount of which is 1% of the monomer mass.

[0043] (2) Dispersing carbon fibers in water, adding monomers, emulsifiers, and initiators, copolymerizing at 80°C for 5 hours, filtering, washing, and drying to obtain modified carbon fibers. The mass ratio of carbon fibers to monomers is 1:2, and the monomers are composed of methyl acrylate and vinyl-terminated dimethyl methyl vinyl (siloxane and polysiloxane) in a mass ratio of 7:1. The emulsifier is fatty alcohol polyoxyethylene ether AEO-9, and the amount is 10% of the monomer mass. The initiator is ammonium persulfate, and the amount is 1% of the monomer mass.

[0044] (3) Adding modified graphene and modified carbon fiber to polyester in a mass ratio of 80:10:10, and mixing them evenly to obtain a premix.

[0045] (4) The premix is ​​added to a twin-screw extruder (main engine speed is 30 Hz, feeder speed is 10 Hz, and operating temperature is 240-280° C.), melt-extruded, cooled and granulated to obtain a graphene / carbon fiber / polyester composite material.

[0046] Example 4

[0047] (1) Graphene is dispersed in water, and monomer, emulsifier and initiator are added, copolymerized at 90°C for 3 hours, filtered, washed with water, and dried to obtain modified graphene. The mass ratio of graphene to monomer is 1:0.5, and the monomer is composed of glycidyl methacrylate and vinyl-terminated dimethyl methyl vinyl (siloxane and polysiloxane) in a mass ratio of 5:1; the emulsifier is fatty alcohol polyoxyethylene ether AEO-9, the amount of which is 10% of the monomer mass; and the initiator is ammonium persulfate, the amount of which is 1% of the monomer mass.

[0048] (2) Dispersing carbon fibers in water, adding monomers, emulsifiers, and initiators, copolymerizing at 70°C for 5 hours, filtering, washing, and drying to obtain modified carbon fibers. The mass ratio of carbon fibers to monomers is 1:3, and the monomers are composed of methyl methacrylate and vinyl-terminated dimethyl methyl vinyl (siloxane and polysiloxane) in a mass ratio of 5:1. The emulsifier is fatty alcohol polyoxyethylene ether AEO-9, and the amount is 10% of the monomer mass. The initiator is ammonium persulfate, and the amount is 0.5% of the monomer mass.

[0049] (3) Adding modified graphene and modified carbon fiber to polycarbonate in a mass ratio of 80:10:10, and mixing them evenly to obtain a premix.

[0050] (4) The premix is ​​added to a twin-screw extruder (main engine speed is 30 Hz, feeder speed is 10 Hz, and operating temperature is 220-260° C.), melt-extruded, cooled and granulated to obtain a graphene / carbon fiber / polycarbonate composite material.

[0051] Example 5

[0052] (1) Graphene is dispersed in water, and monomer, emulsifier and initiator are added, copolymerized at 80°C for 3 hours, filtered, washed with water, and dried to obtain modified graphene. The mass ratio of graphene to monomer is 1:2, and the monomer is composed of methyl methacrylate and vinyl-terminated dimethyl methyl vinyl (siloxane and polysiloxane) in a mass ratio of 7:1; the emulsifier is alkylphenol polyoxyethylene ether OP-10, and the amount used is 8% of the monomer mass; the initiator is ammonium persulfate, and the amount used is 1.5% of the monomer mass.

[0053] (2) Dispersing carbon fibers in water, adding monomers, emulsifiers, and initiators, copolymerizing at 80°C for 4 hours, filtering, washing, and drying to obtain modified carbon fibers. The mass ratio of carbon fibers to monomers is 1:2, and the monomers are composed of hydroxyethyl methacrylate and vinyl-terminated dimethyl methyl vinyl (siloxane and polysiloxane) in a mass ratio of 6:1. The emulsifier is alkylphenol polyoxyethylene ether OP-10, and the amount used is 10% of the monomer mass. The initiator is ammonium persulfate, and the amount used is 1.5% of the monomer mass.

[0054] (3) Adding modified graphene and modified carbon fiber to polycarbonate in a mass ratio of 80:10:10, and mixing them evenly to obtain a premix.

[0055] (4) The premix is ​​added to a twin-screw extruder (main engine speed is 30 Hz, feeder speed is 10 Hz, and operating temperature is 220-260° C.), melt-extruded, cooled and granulated to obtain a graphene / carbon fiber / polycarbonate composite material.

[0056] Example 6

[0057] (1) Graphene is dispersed in water, and monomer, emulsifier and initiator are added, copolymerized at 85°C for 5 hours, filtered, washed with water, and dried to obtain modified graphene. The mass ratio of graphene to monomer is 1:3, and the monomer is composed of methyl acrylate and vinyl-terminated dimethyl methyl vinyl (siloxane and polysiloxane) in a mass ratio of 5:1; the emulsifier is alkylphenol polyoxyethylene ether OP-10, and the amount used is 10% of the monomer mass; the initiator is ammonium persulfate, and the amount used is 2% of the monomer mass.

[0058] (2) Dispersing carbon fibers in water, adding monomers, emulsifiers, and initiators, copolymerizing at 85°C for 4 hours, filtering, washing, and drying to obtain modified carbon fibers. The mass ratio of carbon fibers to monomers is 1:1, and the monomers are composed of methyl methacrylate and vinyl-terminated dimethyl methyl vinyl (siloxane and polysiloxane) in a mass ratio of 8:1. The emulsifier is alkylphenol polyoxyethylene ether OP-10, and the amount used is 10% of the monomer mass. The initiator is ammonium persulfate, and the amount used is 1% of the monomer mass.

[0059] (3) Adding modified graphene and modified carbon fiber to polyester in a mass ratio of 80:10:10, and mixing them evenly to obtain a premix.

[0060] (4) The premix is ​​added to a twin-screw extruder (main engine speed is 30 Hz, feeder speed is 10 Hz, and operating temperature is 240-280° C.), melt-extruded, cooled and granulated to obtain a graphene / carbon fiber / polyester composite material.

[0061] Example 7

[0062] (1) Graphene is dispersed in water, and monomer, emulsifier and initiator are added, copolymerized at 90°C for 3 hours, filtered, washed with water, and dried to obtain modified graphene. The mass ratio of graphene to monomer is 1:2, and the monomer is composed of methyl acrylate and vinyl-terminated dimethyl methyl vinyl (siloxane and polysiloxane) in a mass ratio of 7:1; the emulsifier is alkylphenol polyoxyethylene ether OP-10, and the amount used is 8% of the monomer mass; the initiator is potassium persulfate, and the amount used is 1% of the monomer mass.

[0063] (2) Dispersing carbon fibers in water, adding monomers, emulsifiers, and initiators, copolymerizing at 70°C for 5 hours, filtering, washing, and drying to obtain modified carbon fibers. The mass ratio of carbon fibers to monomers is 1:3, and the monomers are composed of methyl acrylate and vinyl-terminated dimethyl methyl vinyl (siloxane and polysiloxane) in a mass ratio of 8:1. The emulsifier is alkylphenol polyoxyethylene ether OP-10, and the amount used is 5% of the monomer mass. The initiator is potassium persulfate, and the amount used is 1% of the monomer mass.

[0064] (3) Adding modified graphene and modified carbon fiber to polyester in a mass ratio of 80:10:10, and mixing them evenly to obtain a premix.

[0065] (4) The premix is ​​added to a twin-screw extruder (main engine speed is 30 Hz, feeder speed is 10 Hz, and operating temperature is 240-280° C.), melt-extruded, cooled and granulated to obtain a graphene / carbon fiber / polyester composite material.

[0066] Example 8

[0067] (1) Graphene is dispersed in water, and monomer, emulsifier and initiator are added, copolymerized at 90°C for 2 hours, filtered, washed with water, and dried to obtain modified graphene. The mass ratio of graphene to monomer is 1:3, and the monomer is composed of methyl methacrylate and vinyl-terminated dimethyl methyl vinyl (siloxane and polysiloxane) in a mass ratio of 5:1; the emulsifier is alkylphenol polyoxyethylene ether OP-10, and the amount used is 10% of the monomer mass; the initiator is ammonium persulfate, and the amount used is 2% of the monomer mass.

[0068] (2) Dispersing carbon fibers in water, adding monomers, emulsifiers, and initiators, copolymerizing at 85°C for 3 hours, filtering, washing, and drying to obtain modified carbon fibers. The mass ratio of carbon fibers to monomers is 1:2, and the monomers are composed of methyl methacrylate and vinyl-terminated dimethyl methyl vinyl (siloxane and polysiloxane) in a mass ratio of 5:1. The emulsifier is alkylphenol polyoxyethylene ether OP-10, and the amount is 10% of the monomer mass. The initiator is ammonium persulfate, and the amount is 2% of the monomer mass.

[0069] (3) Adding modified graphene and modified carbon fiber to polyester in a mass ratio of 80:10:10, and mixing them evenly to obtain a premix.

[0070] (4) The premix is ​​added to a twin-screw extruder (main engine speed is 30 Hz, feeder speed is 10 Hz, and operating temperature is 240-280° C.), melt-extruded, cooled and granulated to obtain a graphene / carbon fiber / polyester composite material.

[0071] Comparative Example 1

[0072] The method of Example 1 was followed, except that the vinyl-terminated dimethyl methyl vinyl (siloxane and polysiloxane) monomer was replaced with γ-(methacryloyloxy)propyltrimethoxysilane.

[0073] (1) Graphene is dispersed in water, and monomer, emulsifier and initiator are added, copolymerized at 80°C for 3 hours, filtered, washed with water, and dried to obtain modified graphene. The mass ratio of graphene to monomer is 1:1, and the monomer is composed of methyl acrylate and γ-(methacryloyloxy)propyltrimethoxysilane in a mass ratio of 5:1; the emulsifier is alkylphenol polyoxyethylene ether OP-10, and the amount used is 5% of the monomer mass; the initiator is ammonium persulfate, and the amount used is 0.5% of the monomer mass.

[0074] (2) Dispersing carbon fibers in water, adding monomers, emulsifiers, and initiators, copolymerizing at 80°C for 3 hours, filtering, washing, and drying to obtain modified carbon fibers. The mass ratio of carbon fibers to monomers is 1:2, and the monomers are composed of methyl acrylate and γ-(methacryloyloxy)propyltrimethoxysilane in a mass ratio of 8:1. The emulsifier is alkylphenol polyoxyethylene ether OP-10, and the amount used is 10% of the monomer mass. The initiator is ammonium persulfate, and the amount used is 1% of the monomer mass.

[0075] (3) Adding modified graphene and modified carbon fiber to polyester in a mass ratio of 90:5:5, mixing them evenly, and obtaining a premix.

[0076] (4) The premix is ​​added to a twin-screw extruder (main engine speed is 30 Hz, feeder speed is 10 Hz, and operating temperature is 240-280° C.), melt-extruded, cooled and granulated to obtain a graphene / carbon fiber / polyester composite material.

[0077] Comparative Example 2

[0078] The method of Example 1 was followed, except that the vinyl-terminated dimethyl methyl vinyl group (siloxane and polysiloxane) of the monomer was deleted.

[0079] (1) Graphene is dispersed in water, and monomer, emulsifier and initiator are added. The mixture is copolymerized at 80°C for 3 hours, filtered, washed with water and dried to obtain modified graphene. The mass ratio of graphene to monomer is 1:1, the monomer is methyl acrylate, the emulsifier is alkylphenol polyoxyethylene ether OP-10, and the amount used is 5% of the monomer mass; the initiator is ammonium persulfate, and the amount used is 0.5% of the monomer mass.

[0080] (2) Dispersing carbon fibers in water, adding monomers, emulsifiers, and initiators, copolymerizing at 80°C for 3 hours, filtering, washing, and drying to obtain modified carbon fibers. The mass ratio of carbon fibers to monomers is 1:2, the monomer is methyl acrylate, the emulsifier is alkylphenol polyoxyethylene ether OP-10, and the amount is 10% of the monomer mass; and the initiator is ammonium persulfate, and the amount is 1% of the monomer mass.

[0081] (3) Adding modified graphene and modified carbon fiber to polyester in a mass ratio of 90:5:5, mixing them evenly, and obtaining a premix.

[0082] (4) The premix is ​​added to a twin-screw extruder (main engine speed is 30 Hz, feeder speed is 10 Hz, and operating temperature is 240-280° C.), melt-extruded, cooled and granulated to obtain a graphene / carbon fiber / polyester composite material.

[0083] Comparative Example 3

[0084] The method of Example 1 was followed, except that the graphene and carbon fiber were not surface modified.

[0085] (1) Graphene and carbon fiber are added to polyester in a mass ratio of 90:5:5, and the mixture is uniformly mixed to obtain a premix.

[0086] (2) The premix is ​​added to a twin-screw extruder (main engine speed is 30 Hz, feeder speed is 10 Hz, and operating temperature is 240-280° C.), melt-extruded, cooled and granulated to obtain a graphene / carbon fiber / polyester composite material.

[0087] The graphene / carbon fiber / polymer composite materials prepared in the above examples and comparative examples were respectively injection molded into specimens measuring 100 mm × 10 mm × 5 mm. The resulting specimens were then tested for mechanical properties and thermal conductivity. The test results are shown in Table 1. The graphene / carbon fiber / polyester composite material had an injection pressure of 45 MPa, an injection temperature of 285°C, a holding pressure of 35 MPa, and a holding time of 4 seconds; the graphene / carbon fiber / polycarbonate composite material had an injection pressure of 45 MPa, an injection temperature of 250°C, a holding pressure of 35 MPa, and a holding time of 4 seconds.

[0088] The tensile strength is tested according to the standard GB / T 1040.2-2022.

[0089] Thermal conductivity is tested according to standard GB / T 3399-1982.

[0090] Each group of samples was tested three times and the average value was taken.

[0091] Table 1

[0092] Tensile strength (MPa) Thermal conductivity (W / mk) Example 1 42.8 3.25 Example 2 43.7 3.29 Example 3 44.9 3.34 Example 4 55.2 4.07 Example 5 56.4 4.12 Example 6 46.3 3.41 Example 7 45.6 3.58 Example 8 46.9 3.46 Comparative Example 1 37.4 2.71 Comparative Example 2 39.5 2.93 Comparative Example 3 32.6 2.15

[0093] As can be seen from Table 1, the present invention can substantially improve the thermal conductivity and mechanical properties of the graphene / carbon fiber / polyester composite material by using acrylate and vinyl-terminated dimethyl methyl vinyl (siloxane and polysiloxane) as monomers to perform in situ surface modification of graphene and carbon fiber.

[0094] The basic principles, main features, and advantages of the present invention are shown and described above. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and modifications are intended to fall within the scope of the present invention. The scope of protection claimed in the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a graphene / carbon fiber / polymer composite material, characterized in that: The method comprises the following preparation steps: (1) dispersing graphene in water, adding monomer, emulsifier and initiator to carry out copolymerization, filtering, washing with water, and drying to obtain modified graphene; (2) dispersing carbon fibers in water, adding monomers, emulsifiers, and initiators to carry out copolymerization, filtering, washing, and drying to obtain modified carbon fibers; (3) adding modified graphene and modified carbon fiber to the polymer and mixing them uniformly to obtain a premix; (4) The premix is ​​added into a twin-screw extruder, melt-extruded, cooled and granulated to obtain a graphene / carbon fiber / polymer composite material.

2. The method for preparing the graphene / carbon fiber / polymer composite material according to claim 1, wherein: The monomers include acrylate and vinyl-terminated dimethylmethylvinyl (siloxane and polysiloxane), wherein the mass ratio of acrylate to vinyl-terminated dimethylmethylvinyl (siloxane and polysiloxane) is (5-8):

1.

3. The method for preparing the graphene / carbon fiber / polymer composite material according to claim 2, wherein: The acrylic acid ester is one or more of methyl acrylate, ethyl acrylate, butyl acrylate, isobutyl acrylate, methyl methacrylate, ethyl methacrylate, hydroxyethyl methacrylate, and glycidyl methacrylate.

4. The method for preparing the graphene / carbon fiber / polymer composite material according to claim 1, wherein: The initiator is a water-soluble initiator, and the amount used is 0.1-2% of the monomer mass.

5. The method for preparing the graphene / carbon fiber / polymer composite material according to claim 1, wherein: The mass ratio of the graphene to the monomer is 1:(0.5-3).

6. The method for preparing the graphene / carbon fiber / polymer composite material according to claim 1, wherein: The mass ratio of the carbon fiber to the monomer is 1:(0.5-3).

7. The method for preparing the graphene / carbon fiber / polymer composite material according to claim 1, wherein: The emulsifier is a nonionic surfactant, and the amount used is 2-10% of the monomer mass.

8. The method for preparing the graphene / carbon fiber / polymer composite material according to claim 1, wherein: The reaction temperature of the copolymerization reaction is 70-90° C., and the reaction time is 2-5 hours.

9. The method for preparing the graphene / carbon fiber / polymer composite material according to claim 1, wherein: The polymer is one or more of polyester, polycarbonate and polyester imide.

10. The method for preparing the graphene / carbon fiber / polymer composite material according to claim 1, wherein: The mass ratio of the polymer to the modified graphene and the modified carbon fiber is (80-90):(1-10):(1-10).