Preparation method of graphene-carbon fiber polypropylene composite master batch

Abstract

The application discloses a preparation method of graphene-carbon fiber polypropylene composite master batch, 1) graphene, a surfactant and an organic solvent are mixed to obtain modified graphene dispersion liquid; 2) the modified graphene dispersion liquid, the organic solvent, an alkyl aluminum compound solution, a silane coupling agent and a catalyst are placed in a high-pressure polymerization kettle, and a reaction is carried out in an atmosphere of propylene to obtain graphene-polypropylene composite material; 3) the graphene-polypropylene composite material, carbon fiber and an antioxidant are mixed, extruded through a double-screw extruder and granulated to obtain the graphene-carbon fiber polypropylene composite master batch. Through the in-situ polymerization method, polypropylene is synthesized on the graphene, the graphene plays a role of a nucleating agent, promotes crystallization of the polypropylene, meanwhile, the compatibility of the graphene and the polypropylene is improved, the graphene can be uniformly distributed in the graphene-polypropylene composite material, and the graphene-carbon fiber polypropylene composite material prepared from the material has excellent mechanical properties, electric conductivity and thermal conductivity.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of high polymer composite materials, and particularly relates to a preparation method of a graphene-carbon fiber polypropylene composite material master batch. BACKGROUND

[0002] Polypropylene fiber, also known as polypropylene fiber, is the second largest general resin in terms of production, and is one of the most widely used general resins in the world, only next to polyethylene. Polypropylene (PP) is a low-cost, widely used, and easily processed thermoplastic. Due to the advantages of abundant raw materials, balanced mechanical properties, excellent chemical resistance, high transparency, stress cracking resistance, and easy processing, polypropylene (PP) is widely used in the automotive, electrical, daily necessities, textile clothing, and packaging industries. However, the mechanical properties and heat stability of polypropylene (PP) are insufficient, and it has the disadvantages of easy static electricity and easy aging degradation, which limits its application.

[0003] Carbon fiber is a new type of fiber material with a carbon content of more than 95%, high strength, and high modulus. Carbon fiber has the characteristics of "soft outside and hard inside", light weight compared to aluminum, high strength compared to steel, corrosion resistance, and high modulus, and is an important material in national defense and civilian fields. Carbon fiber can be used as an excellent reinforcing material due to its high strength, low density, high temperature resistance, water resistance, and corrosion resistance. Adding carbon fiber to high polymers can significantly improve the comprehensive performance of high polymer composites.

[0004] Graphene is a two-dimensional honeycomb-like crystal composed of single-layer hexagonal carbon atoms, which has excellent mechanical properties, outstanding electrical conductivity and thermal conductivity, high specific surface area, excellent adsorption performance, and significant interface effect, making it very suitable for the development of high-performance and multifunctional polymer nanocomposites. When the content of graphene in the composite material is low, graphene can be used as a reinforcing agent to improve the mechanical properties and thermal stability of the polymer, without affecting other excellent properties of the composite material.

[0005] Due to the large specific surface area and interface interaction of graphene, it is easy to agglomerate in the polypropylene matrix, and the general melt blending method cannot achieve high dispersion effect, so the excellent performance of graphene material cannot be achieved.

[0006] At present, there are various graphene / polypropylene composites and carbon fiber / polypropylene composites, but most of them are prepared by melt extrusion after physical mixing.

[0007] A graphene-polypropylene composite material and a preparation method thereof are disclosed in Chinese patent document CN112409687A. The composite material is prepared by physical mixing and melt extrusion. Graphene has a layered structure and is uniformly dispersed in the polypropylene matrix, which can improve the stress bearing capacity of the polypropylene matrix.

[0008] However, the uniformity of graphene in the composite material prepared by this method cannot be guaranteed, so the mechanical property enhancement effect cannot be guaranteed. Moreover, the addition of single graphene does not significantly increase the electrical and thermal conductivity, limiting its application in electrical and thermal conductivity.

[0009] Therefore, the present application is proposed. SUMMARY

[0010] The present application aims to provide a preparation method of a graphene-carbon fiber polypropylene composite material master batch, so as to achieve the purpose of excellent mechanical properties and good electrical and thermal conductivity of the graphene-carbon fiber polypropylene composite material.

[0011] To solve the above technical problems, the basic idea of the technical solution of the present application is as follows:

[0012] A preparation method of a graphene-carbon fiber polypropylene composite material master batch comprises the following preparation steps:

[0013] 1) Mix graphene, a surfactant and an organic solvent to obtain a modified graphene dispersion liquid;

[0014] 2) Put the modified graphene dispersion liquid, an organic solvent, an alkyl aluminum compound solution, a silane coupling agent and a catalyst into a high-pressure polymerization kettle, and react in an atmosphere of propylene to obtain a graphene polypropylene composite material;

[0015] 3) Mix the graphene-polypropylene composite material, carbon fiber and antioxidant, and extrude and granulate by a double-screw extruder to obtain a graphene-carbon fiber polypropylene composite material master batch.

[0016] The present application synthesizes polypropylene on graphene by in-situ polymerization. Graphene acts as a nucleating agent to promote the crystallization of polypropylene, and also disperses in polypropylene, improving the compatibility of graphene and polypropylene. A graphene-polypropylene composite material with uniform distribution of graphene is prepared. Further, the graphene-polypropylene composite material is mixed with carbon fiber and antioxidant, extruded and granulated to obtain a graphene-carbon fiber polypropylene composite material master batch with excellent mechanical properties and excellent electrical and thermal conductivity.

[0017] The surface active agent in the step 1) includes one or more of ionic surface active agent, non-ionic surface active agent; the ionic surface active agent includes hexadecanoic acid amide propyl trimethyl ammonium chloride; the non-ionic surface active agent includes fatty acid glyceride type non-ionic surface active agent, such as: glycerol monostearate.

[0018] The modified graphene dispersion liquid is prepared by adding the surface active agent, so that the graphene can be uniformly dispersed in the dispersion liquid, to ensure that the graphene is uniformly dispersed in the polypropylene in the subsequent polymerization reaction.

[0019] Further, in the step 2), the high-pressure polymerization kettle is first vacuumed, then the propylene gas is filled to the normal pressure state, and then the organic solvent, the alkyl aluminum compound solution, the silane coupling agent, the catalyst and the modified graphene dispersion liquid are sequentially added for reaction.

[0020] Further, in the step 2), the high-pressure polymerization kettle is vacuumed at 40-80℃, then the propylene gas is filled to the normal pressure state, and then the organic solvent, the alkyl aluminum compound solution, the silane coupling agent, the catalyst and the modified graphene dispersion liquid are added, and then the propylene gas is continuously filled to the pressure increased to 0.2-0.8Mpa for reaction.

[0021] In the polymerization reaction, the interface bonding force between the graphene and the polypropylene is enhanced by adding the silane coupling agent, further enabling the graphene to be tightly combined in the polypropylene, and the graphene is fully and reasonably utilized, which greatly improves the mechanical properties of the polypropylene.

[0022] Further, in the step 2), the solute alkyl aluminum compound in the alkyl aluminum compound solution includes one or more of triethyl aluminum, triisobutyl aluminum and tri-n-butyl aluminum, and the solvent includes one or more of n-pentane, n-hexane, n-heptane and n-octane;

[0023] Preferably, the concentration of the alkyl aluminum compound solution is 1-3mol / L;

[0024] Preferably, the addition amount of the alkyl aluminum compound solution is 0.1-50mmol / kg propylene.

[0025] Further, in the step 2), the silane coupling agent includes one or more of methoxysilane, aminosilane, vinylsilane and methacryloyloxysilane.

[0026] Preferably, the addition amount of the silane coupling agent is 0.1-3mmol / g catalyst.

[0027] Further, in the step 2), the catalyst includes one or both of Ziegler-Natta catalyst and metallocene catalyst.

[0028] The Ziegler-Natta catalyst is selected from one or more of MgCl2 / TiCl4, TiCl4 / BuMgCl, TiCl4 / AlEt3, SiO2 / TiCl4, Avant Z-N catalyst, SHAC 330 catalyst, RCE02P polypropylene catalyst, LYNX2000 series catalyst;

[0029] The metallocene catalyst is selected from one or two of APE1S metallocene catalyst, PMP-01 supported metallocene polypropylene catalyst, bridged bis-cyclozirconium catalyst, bridged bis-fluorenyl cyclozirconium catalyst, bridged single-fluorenyl monocyclopentadienyl cyclozirconium metal compound catalyst, CGC catalyst, Avant M series catalyst.

[0030] Further, in the step 1), the organic solvent is selected from one or more of n-pentane, n-hexane, n-heptane, n-octane, n-decane.

[0031] Further, in the step 1), the mass ratio of graphene to surfactant is 1:0.05-1.5.

[0032] Further, in the step 1), the mass percentage concentration of graphene in the modified graphene dispersion liquid is 5-50%.

[0033] Further, in the step 1), in the step (1), the graphene is in powder form, and the flake diameter is less than 200um;

[0034] Preferably, the graphene is selected from one or more of pure graphene, graphene oxide, reduced graphene oxide, and organically modified graphene.

[0035] Further, in the step 3), the mass fraction of each component in the graphene-carbon fiber polypropylene composite master batch is:

[0036] Graphene-polypropylene composite 60%-95%

[0037] Carbon fiber 5%-40%

[0038] Antioxidant 0.1%-1%;

[0039] Preferably, in the step 3), the parameters of the twin-screw extruder are set as follows: the main machine speed is 100-300 r / min, the feeding speed is 3-10 r / min, and the extrusion granulation temperature is 180-240°C.

[0040] Preferably, the temperature of the first zone of the twin-screw extruder is 180-190 DEG C, the temperature of the second zone is 190-200 DEG C, the temperature of the third zone is 200-210 DEG C, the temperature of the fourth zone is 210-220 DEG C, the temperature of the fifth zone is 220-230 DEG C, the temperature of the sixth zone is 230-240 DEG C, and the temperature of the head is 230-240 DEG C.

[0041] In the step 2), an acid alcohol solution is added to the system to terminate the reaction.

[0042] Compared with the prior art, the application has the following beneficial effects.

[0043] The graphene plays a role of nucleating agent, promotes the crystallization of the polypropylene, and also disperses the graphene in the polypropylene, improves the compatibility of the graphene and the polypropylene, and prepares the graphene-polypropylene composite material with uniform graphene distribution. DETAILED DESCRIPTION

[0044] To make the object, technical scheme and advantages of the application clearer, the technical scheme will be clearly and completely described below, and the following examples are used to illustrate the application, but not to limit the scope of the application.

[0045] Example 1

[0046] (1) 15g of graphene and 10g of hexadecanoic acid amide propyl trimethyl ammonium chloride are weighed and added into 100ml of n-hexane, and ultrasonic dispersion is carried out for 1-2h to obtain a modified graphene dispersion liquid;

[0047] (2) A high-pressure polymerization kettle is vacuumed at 60 DEG C, and propylene gas is filled to normal pressure, then 5L of n-hexane, 100ml of tri-n-butyl aluminum solution (solvent is 2mol / L n-heptane solution), 1mmol of diphenyl dimethoxysilane, 0.5g of TiCl4 / BuMgCl and the modified graphene dispersion liquid prepared in step (1) are sequentially added, propylene is continuously filled to make the pressure rise to 0.6MPa, and reaction is carried out at 60 DEG C for 0.3h, then the propylene filling is stopped, and 10% acid alcohol solution is added to the system to terminate the reaction. The reaction product is washed with ethanol and deionized water for several times, and is dried under vacuum at 60 DEG C to obtain a graphene-polypropylene composite material.

[0048] (3) 845g of the graphene-polypropylene composite material prepared in step (2), 150g of carbon fiber and 5g of antioxidant 1010 are weighed and added into a high-speed mixer to mix uniformly.

[0049] (4) The double screw extruder is used for extrusion granulation, and the parameters of the double screw extruder are set as follows: the main machine rotating speed is 200 r / min; the feeding rotating speed is 5 r / min; the temperature of the first zone of the double screw extruder is 180 ℃, the temperature of the second zone of the double screw extruder is 190 ℃, the temperature of the third zone of the double screw extruder is 200 ℃, the temperature of the fourth zone of the double screw extruder is 210 ℃, the temperature of the fifth zone of the double screw extruder is 220 ℃, the temperature of the sixth zone of the double screw extruder is 230 ℃, and the temperature of the head of the double screw extruder is 230 ℃. After extrusion, cooling, air drying, and entering the granulator for granulation, the graphene-carbon fiber polypropylene composite functional master batch is obtained.

[0050] Example 2

[0051] (1) 10 g of graphene, 15 g of hexadecanoic acid amide propyl trimethyl ammonium chloride, and 100 ml of n-hexane are weighed and added, and ultrasonic dispersion is performed for 1-2 h to obtain a modified graphene dispersion liquid;

[0052] (2) The high-pressure polymerization kettle is vacuumed at 60 ℃, and propylene gas is filled to the normal pressure state. Then, 5 L of n-hexane, 100 ml of tri-n-butyl aluminum solution (2 mol / L n-heptane solution), 1 mmol of diphenyl dimethoxysilane, 0.5 g of TiCl4 / BuMgCl, and the modified graphene dispersion liquid prepared in step (1) are sequentially added. Propylene is continuously introduced to increase the pressure to 0.6 MPa, and the reaction is carried out at 60 ℃ for 0.3 h. The reaction is terminated by adding 10% acid alcohol solution to the system. The reaction product is washed with ethanol and deionized water several times, and then dried under vacuum at 60 ℃ to obtain a graphene polypropylene composite material.

[0053] (3) 845 g of the graphene polypropylene composite material prepared in step (2), 150 g of carbon fiber, and 5 g of antioxidant 1010 are weighed and added to a high-speed mixer and uniformly mixed.

[0054] (4) The double screw extruder is used for extrusion granulation, and the parameters of the double screw extruder are set as follows: the main machine rotating speed is 200 r / min; the feeding rotating speed is 5 r / min; the temperature of the first zone of the double screw extruder is 180 ℃, the temperature of the second zone of the double screw extruder is 190 ℃, the temperature of the third zone of the double screw extruder is 200 ℃, the temperature of the fourth zone of the double screw extruder is 210 ℃, the temperature of the fifth zone of the double screw extruder is 220 ℃, the temperature of the sixth zone of the double screw extruder is 230 ℃, and the temperature of the head of the double screw extruder is 230 ℃. After extrusion, cooling, air drying, and entering the granulator for granulation, the graphene-carbon fiber polypropylene composite functional master batch is obtained.

[0055] Example 3

[0056] (1) Take 20g graphene, 10g hexadecanoic acid amide propyl trimethyl ammonium chloride, and add to 100ml n-hexane, ultrasonic dispersion for 1-2h, to obtain modified graphene dispersion;

[0057] (2) The high-pressure polymerization kettle is vacuumed at 60°C, and then 5L n-hexane, 100ml tri-n-butyl aluminum solution (2mol / L n-heptane solution), 1mmol of diphenyl dimethoxysilane, 0.5g of TiCl4 / BuMgCl and the modified graphene dispersion prepared in step (1) are sequentially added, and then the pressure is increased to 0.6MPa by continuously feeding propylene, and the reaction is carried out at 60°C for 0.3h, and then the reaction is terminated by adding 10% acid alcohol solution to the system. The reaction product is washed with ethanol and deionized water several times, and then dried under vacuum at 60°C to obtain a graphene-polypropylene composite material.

[0058] (3) Take 845g graphene-polypropylene composite material prepared in step (2), 150g carbon fiber and 5g antioxidant 1010, and mix them in a high-speed mixer.

[0059] (4) The double-screw extruder is used for extrusion granulation, and the parameters of the double-screw extruder are set as follows: the main machine speed is 200r / min; the feeding speed is 5r / min; the temperature of the first zone of the double-screw extruder is 180°C, the temperature of the second zone of the double-screw extruder is 190°C, the temperature of the third zone of the double-screw extruder is 200°C, the temperature of the fourth zone of the double-screw extruder is 210°C, the temperature of the fifth zone of the double-screw extruder is 220°C, the temperature of the sixth zone of the double-screw extruder is 230°C, and the temperature of the die head of the double-screw extruder is 230°C. After extrusion, cooling, air drying and entering the pelletizer, a graphene-carbon fiber polypropylene composite functional masterbatch is obtained.

[0060] Example 4

[0061] (1) Take 20g graphene, 10g hexadecanoic acid amide propyl trimethyl ammonium chloride, and add to 100ml n-hexane, ultrasonic dispersion for 1-2h, to obtain modified graphene dispersion;

[0062] (2) The high-pressure polymerization kettle was vacuumed at 60°C, and propylene gas was filled to normal pressure. Then 5L of n-hexane, 100ml of tri-n-butyl aluminum solution (solvent: 2mol / L n-heptane solution), 1mmol of diphenyl dimethoxysilane, 0.5g of TiCl4 / BuMgCl and the modified graphene dispersion prepared in step (1) were sequentially added. The pressure was increased to 0.6MPa by continuously filling propylene. The reaction was carried out at 60°C for 0.3h. The reaction was terminated by adding 10% acid alcohol solution to the system. The reaction product was washed with ethanol and deionized water for several times, and then dried under vacuum at 60°C to obtain a graphene-polypropylene composite material.

[0063] (3) 945g of the graphene-polypropylene composite material prepared in step (2), 50g of carbon fiber and 5g of antioxidant 1010 were weighed and mixed in a high-speed mixer.

[0064] (4) The graphene-carbon fiber-polypropylene composite material was prepared by using a double-screw extruder. The parameters of the double-screw extruder were set as follows: the rotation speed of the main machine was 200r / min; the feeding rotation speed was 5r / min; the temperature of the first zone of the double-screw extruder was 180°C; the temperature of the second zone of the double-screw extruder was 190°C; the temperature of the third zone of the double-screw extruder was 200°C; the temperature of the fourth zone of the double-screw extruder was 210°C; the temperature of the fifth zone of the double-screw extruder was 220°C; the temperature of the sixth zone of the double-screw extruder was 230°C; and the temperature of the die head of the double-screw extruder was 230°C. After extrusion, the graphene-carbon fiber-polypropylene composite material was cooled, air-dried and then granulated in a pelletizer to obtain a graphene-carbon fiber-polypropylene composite functional masterbatch.

[0065] Example 5

[0066] (1) 15g of graphene and 10g of hexadecanoic acid amide propyl trimethyl ammonium chloride were weighed and added to 100ml of n-hexane, and ultrasonic dispersion was carried out for 1-2h to obtain a modified graphene dispersion;

[0067] (2) The high-pressure polymerization kettle was vacuumed at 60°C, and propylene gas was filled to normal pressure. Then 5L of n-hexane, 100ml of tri-n-butyl aluminum solution (solvent: 2mol / L n-heptane solution), 1mmol of diphenyl dimethoxysilane, 0.5g of TiCl4 / BuMgCl and the modified graphene dispersion prepared in step (1) were sequentially added. The pressure was increased to 0.6MPa by continuously filling propylene. The reaction was carried out at 60°C for 0.3h. The reaction was terminated by adding 10% acid alcohol solution to the system. The reaction product was washed with ethanol and deionized water for several times, and then dried under vacuum at 60°C to obtain a graphene-polypropylene composite material.

[0068] (3) Take 795g of graphene-polypropylene composite material prepared in step (2), 200g of carbon fiber and 5g of antioxidant 1010 respectively into a high-speed mixer and mix uniformly.

[0069] (4) The double screw extruder is used for extrusion granulation, and the parameters of the double screw extruder are set as follows: the main machine speed is 200 r / min; the feeding speed is 5 r / min; the temperature of the first zone of the double screw extruder is 180℃, the temperature of the second zone of the double screw extruder is 190℃, the temperature of the third zone of the double screw extruder is 200℃, the temperature of the fourth zone of the double screw extruder is 210℃, the temperature of the fifth zone of the double screw extruder is 220℃, the temperature of the sixth zone of the double screw extruder is 230℃, and the temperature of the head of the double screw extruder is 230℃. After extrusion, cooling, air drying and entering the granulator, graphene-carbon fiber polypropylene composite functional masterbatch is obtained.

[0070] Example 6

[0071] (1) Take 10g of graphene, 0.5g of hexadecanoic acid amide propyl trimethyl ammonium chloride and add them into 20ml of n-heptane, ultrasonic dispersion for 1-2h, to obtain modified graphene dispersion;

[0072] (2) The high-pressure polymerization kettle is vacuumed at 80℃, and then filled with propylene gas to normal pressure. Then 5L of n-hexane, 100ml of triisobutyl aluminum (solvent is 3mol / L n-heptane solution), 1mmol of diphenyl dimethoxysilane, 0.5g of PMP-01 carrier type metallocene polypropylene catalyst and the modified graphene dispersion prepared in step (1) are sequentially added. Continue to introduce propylene to increase the pressure to 0.8MPa, and react at 80℃ for 0.3h. Stop introducing propylene. The reaction product is washed with ethanol and deionized water several times, and then dried under vacuum at 80℃ to obtain a graphene polypropylene composite material.

[0073] (3) Take 600g of graphene polypropylene composite material prepared in step (2), 390g of carbon fiber and 10g of antioxidant 1010 respectively into a high-speed mixer and mix uniformly.

[0074] (4) The double screw extruder is used for extrusion granulation, and the parameters of the double screw extruder are set as follows: the main machine speed is 300 r / min; the feeding speed is 10 r / min; the temperature of the first zone of the double screw extruder is 190℃, the temperature of the second zone of the double screw extruder is 200°C, the temperature of the third zone of the double screw extruder is 210℃, the temperature of the fourth zone of the double screw extruder is 220C, the temperature of the fifth zone of the double screw extruder is 230℃, the temperature of the sixth zone of the double screw extruder is 240℃, and the temperature of the head of the double screw extruder is 240℃. After extrusion, cooling, air drying and entering the granulator, graphene-carbon fiber polypropylene composite functional masterbatch is obtained.

[0075] Example 7

[0076] (1) Take 10 g of reduced graphene oxide, 10 g of hexadecanoic acid amide propyl trimethyl ammonium chloride, and add to 200 ml of n-decane, ultrasonic dispersion for 1-2 h, to obtain a modified graphene dispersion;

[0077] (2) The high-pressure polymerization kettle is vacuumed at 40°C, and then filled with propylene gas to normal pressure, and then 5L of n-hexane, 100 ml of triethylaluminum solution (solvent is 1 mol / L n-heptane solution), 3 mmol of diphenyl dimethoxysilane, 1 g of bridged single fluorenyl monocyclopentadienyl metallocene compound catalyst and the modified graphene dispersion prepared in step (1) are added in turn, and the pressure is raised to 0.2 MPa by continuously feeding propylene, and the reaction is carried out at 40°C for 0.3 h, and then 10% acid alcohol solution is added to terminate the reaction. The reaction product is washed with ethanol and deionized water several times, and then dried under vacuum at 40°C to obtain a graphene-polypropylene composite material.

[0078] (3) Take 900 g of the graphene-polypropylene composite material prepared in step (2), 99 g of carbon fiber and 1 g of antioxidant 1010, and mix them in a high-speed mixer.

[0079] (4) Extrusion granulation is carried out by using a twin-screw extruder, and the parameters of the twin-screw extruder are set as follows: the main machine speed is 100 r / min; the feeding speed is 3 r / min; the temperature of the first zone of the twin-screw extruder is 180°C, the temperature of the second zone of the twin-screw extruder is 190°C, the temperature of the third zone of the twin-screw extruder is 200°C, the temperature of the fourth zone of the twin-screw extruder is 210°C, the temperature of the fifth zone of the twin-screw extruder is 220°C, the temperature of the sixth zone of the twin-screw extruder is 230°C, and the temperature of the die head of the twin-screw extruder is 230°C. After extrusion, cooling, air drying and entering the pelletizer, a graphene-carbon fiber polypropylene composite functional masterbatch is obtained.

[0080] Example 8

[0081] (1) Take 10 g of reduced graphene oxide, 10 g of hexadecanoic acid amide propyl trimethyl ammonium chloride, and add to 40 ml of n-pentane, ultrasonic dispersion for 1-2 h, to obtain a modified graphene dispersion;

[0082] (2) The high-pressure polymerization kettle was vacuumed at 50°C, and then filled with propylene gas to normal pressure. Then 5L of n-hexane, 100ml of triisobutyl aluminum solution (solvent: 2mol / L n-heptane solution), 0.1mmol of diphenyldimethoxysilane, 1g of APE1S metallocene catalyst and the modified graphene dispersion prepared in step (1) were sequentially added. Then propylene was continuously fed to increase the pressure to 0.2MPa, and the reaction was carried out at 50°C for 0.3h. Then the propylene feeding was stopped, and 10% acid alcohol solution was added to terminate the reaction. The reaction product was washed with ethanol and deionized water for several times, and then dried under vacuum at 50°C to obtain a graphene-polypropylene composite material.

[0083] (3) 599g of the graphene-polypropylene composite material prepared in step (2), 400g of carbon fiber and 1g of antioxidant 1010 were respectively added into a high-speed mixer and uniformly mixed.

[0084] (4) The double-screw extruder was used for extrusion granulation. The parameters of the double-screw extruder were set as follows: the main machine rotation speed was 200r / min; the feeding rotation speed was 6r / min; the temperature of the first zone of the double-screw extruder was 185°C, the temperature of the second zone was 195°C, the temperature of the third zone was 205°C, the temperature of the fourth zone was 215°C, the temperature of the fifth zone was 225°C, the temperature of the sixth zone was 235°C, and the temperature of the die head was 235°C. After extrusion, cooling, air drying and entering the granulator, a graphene-carbon fiber polypropylene composite functional masterbatch was obtained.

[0085] Example 9

[0086] (1) 10g of graphene oxide and 10g of glycerol monostearate were added into 40ml of n-pentane, and ultrasonic dispersion was carried out for 1-2h to obtain a modified graphene dispersion;

[0087] (2) The high-pressure polymerization kettle was vacuumed at 50°C, and then filled with propylene gas to normal pressure. Then 5L of n-hexane, 100ml of triisobutyl aluminum solution (solvent: 2mol / L n-heptane solution), 0.1mmol of diphenyldimethoxysilane, 1g of bridged fluorenyl metallocene zirconium catalyst and the modified graphene dispersion prepared in step (1) were sequentially added. Then propylene was continuously fed to increase the pressure to 0.2MPa, and the reaction was carried out at 50°C for 0.3h. Then the propylene feeding was stopped, and 10% acid alcohol solution was added to terminate the reaction. The reaction product was washed with ethanol and deionized water for several times, and then dried under vacuum at 50°C to obtain a graphene-polypropylene composite material.

[0088] (3) 942g of the graphene-polypropylene composite material prepared in step (2), 50g of carbon fiber and 8g of antioxidant 1010 were respectively added into a high-speed mixer and uniformly mixed.

[0089] (4) The double screw extruder is used for extrusion granulation, and the parameters of the double screw extruder are set as follows: the main machine speed is 200 r / min; the feeding speed is 6 r / min; the temperature of the first zone of the double screw extruder is 185 ℃, the temperature of the second zone of the double screw extruder is 195 ℃, the temperature of the third zone of the double screw extruder is 205 ℃, the temperature of the fourth zone of the double screw extruder is 215 ℃, the temperature of the fifth zone of the double screw extruder is 225 ℃, the temperature of the sixth zone of the double screw extruder is 235 ℃, and the temperature of the head of the double screw extruder is 235 ℃. After extrusion, cooling, air drying, and entering the granulator for granulation, the graphene-carbon fiber polypropylene composite functional master batch is obtained.

[0090] Comparative Example 1

[0091] (1) The high-pressure polymerization kettle is vacuumed at 60 ℃, and propylene gas is filled to the normal pressure state, and then 5 L of n-hexane, 100 ml of tri-n-butyl aluminum solution (solvent is 2 mol / L n-heptane solution), 1 mmol of diphenyldimethoxysilane, and 0.5 g of TiCl4 / BuMgCl are sequentially added. Propylene is continuously introduced to increase the pressure to 0.6 MPa, and the reaction is carried out at 60 ℃ for 0.3 h. The propylene is stopped, and 10% acid alcohol solution is added to the system to terminate the reaction. The reaction product is washed with ethanol and deionized water several times, and then dried under vacuum at 60 ℃ to obtain pure polypropylene.

[0092] (2) 995 g of the pure polypropylene prepared in step (1) and 5 g of antioxidant 1010 are respectively added to a high-speed mixer and uniformly mixed.

[0093] (3) The double screw extruder is used for extrusion granulation, and the parameters of the double screw extruder are set as follows: the main machine speed is 200 r / min; the feeding speed is 5 r / min; the temperature of the first zone of the double screw extruder is 180 ℃, the temperature of the second zone of the double screw extruder is 190 ℃, the temperature of the third zone of the double screw extruder is 200 ℃, the temperature of the fourth zone of the double screw extruder is 210 ℃, the temperature of the fifth zone of the double screw extruder is 220 ℃, the temperature of the sixth zone of the double screw extruder is 230 ℃, and the temperature of the head of the double screw extruder is 230 ℃. After extrusion, cooling, air drying, and entering the granulator for granulation, the polypropylene master batch is obtained.

[0094] Comparative Example 2

[0095] (1) 15 g of graphene and 10 g of hexadecanoic acid amide propyltrimethylammonium chloride are added to 100 ml of n-hexane, and ultrasonic dispersion is performed for 1-2 h to obtain a modified graphene dispersion liquid;

[0096] (2) The high-pressure polymerization kettle was vacuumed at 60°C, and then filled with propylene gas to normal pressure. Then 5L of n-hexane, 100ml of tri-n-butyl aluminum solution (solvent: 2mol / L n-heptane solution), 1mmol of diphenyl dimethoxysilane, 0.5g of TiCl4 / BuMgCl, and the modified graphene dispersion prepared in step (1) were sequentially added. Then propylene was continuously fed to increase the pressure to 0.6MPa, and the reaction was carried out at 60°C for 0.3h. Then the propylene feeding was stopped, and 10% acid alcohol solution was added to terminate the reaction. The reaction product was washed with ethanol and deionized water for several times, and then dried under vacuum at 60°C to obtain a graphene-polypropylene composite material.

[0097] (3) 995g of the graphene-polypropylene composite material prepared in step (2) and 5g of antioxidant 1010 were respectively added into a high-speed mixer and uniformly mixed.

[0098] (4) The double-screw extruder was used for extrusion granulation. The parameters of the double-screw extruder were set as follows: the main machine rotation speed was 200r / min; the feeding rotation speed was 5r / min; the temperature of the first zone of the double-screw extruder was 180°C, the temperature of the second zone of the double-screw extruder was 190°C, the temperature of the third zone of the double-screw extruder was 200°C, the temperature of the fourth zone of the double-screw extruder was 210°C, the temperature of the fifth zone of the double-screw extruder was 220°C, the temperature of the sixth zone of the double-screw extruder was 230°C, and the temperature of the head of the double-screw extruder was 230°C. After extrusion, cooling, air-drying, and entering the granulator, a graphene / propylene composite functional masterbatch was obtained.

[0099] Comparative Example 3

[0100] (1) The high-pressure polymerization kettle was vacuumed at 60°C, and then filled with propylene gas to normal pressure. Then 5L of n-hexane, 100ml of tri-n-butyl aluminum solution (solvent: 2mol / L n-heptane solution), 1mmol of diphenyl dimethoxysilane, and 0.5g of TiCl4 / BuMgCl were sequentially added. Then propylene was continuously fed to increase the pressure to 0.6MPa, and the reaction was carried out at 60°C for 0.3h. Then the propylene feeding was stopped, and 10% acid alcohol solution was added to terminate the reaction. The reaction product was washed with ethanol and deionized water for several times, and then dried under vacuum at 60°C to obtain pure polypropylene.

[0101] (2) 845g of the pure polypropylene prepared in step (1), 150g of carbon fiber, and 5g of antioxidant 1010 were respectively added into a high-speed mixer and uniformly mixed.

[0102] (3) The double screw extruder was used for extrusion granulation, and the parameters of the double screw extruder were set as follows: the main machine speed was 200 r / min; the feeding speed was 5 r / min; the temperature of the first zone of the double screw extruder was 180 ℃, the temperature of the second zone of the double screw extruder was 190 ℃, the temperature of the third zone of the double screw extruder was 200 ℃, the temperature of the fourth zone of the double screw extruder was 210 ℃, the temperature of the fifth zone of the double screw extruder was 220 ℃, the temperature of the sixth zone of the double screw extruder was 230 ℃, and the temperature of the head of the double screw extruder was 230 ℃. After extrusion, cooling, air drying, and entering the granulator for granulation, the carbon fiber / propylene functional master batch was obtained.

[0103] Comparative Example 4

[0104] (1) The high-pressure polymerization kettle was vacuumed at 60 ℃, and propylene gas was filled to the normal pressure state, and then 5 L of n-hexane, 100 ml of tri-n-butyl aluminum solution (solvent: 2 mol / L n-heptane solution), 1 mmol of diphenyldimethoxysilane, and 0.5 g of TiCl4 / BuMgCl were sequentially added. Propylene was continuously introduced to increase the pressure to 0.6 MPa, and the reaction was carried out at 60 ℃ for 0.3 h. The propylene was stopped, and 10% acid alcohol solution was added to the system to terminate the reaction. The reaction product was washed with ethanol and deionized water several times, and then dried under vacuum at 60 ℃ to obtain pure polypropylene.

[0105] (2) 830 g of the pure polypropylene prepared in step (1), 15 g of graphene, 150 g of carbon fiber, and 5 g of antioxidant 1010 were weighed and added to a high-speed mixer to mix uniformly.

[0106] (3) The double screw extruder was used for extrusion granulation, and the parameters of the double screw extruder were set as follows: the main machine speed was 200 r / min; the feeding speed was 5 r / min; the temperature of the first zone of the double screw extruder was 180 ℃, the temperature of the second zone of the double screw extruder was 190 ℃, the temperature of the third zone of the double screw extruder was 200 ℃, the temperature of the fourth zone of the double screw extruder was 210 ℃, the temperature of the fifth zone of the double screw extruder was 220 ℃, the temperature of the sixth zone of the double screw extruder was 230 ℃, and the temperature of the head of the double screw extruder was 230 ℃. After extrusion, cooling, air drying, and entering the granulator for granulation, the carbon fiber / propylene functional master batch was obtained.

[0107] Comparative Example 5

[0108] (1) 15 g of graphene was weighed and added to 100 ml of n-hexane, and ultrasonic dispersion was carried out for 1-2 h to obtain a modified graphene dispersion liquid;

[0109] (2) The high-pressure polymerization kettle was vacuumed at 60°C, and then filled with propylene gas to normal pressure. Then 5L of n-hexane, 100ml of tri-n-butyl aluminum solution (solvent: 2mol / L n-heptane solution), 1mmol of diphenyl dimethoxysilane, 0.5g of TiCl4 / BuMgCl and the modified graphene dispersion prepared in step (1) were sequentially added. Then propylene was continuously fed to increase the pressure to 0.6MPa, and the reaction was carried out at 60°C for 0.3h. Then the propylene feeding was stopped, and 10% acid alcohol solution was added to terminate the reaction. The reaction product was washed with ethanol and deionized water for several times, and then dried under vacuum at 60°C to obtain a graphene-polypropylene composite material.

[0110] (3) 845g of the graphene-polypropylene composite material prepared in step (2), 150g of carbon fiber and 5g of antioxidant 1010 were respectively added into a high-speed mixer and uniformly mixed.

[0111] (4) The double-screw extruder was used for extrusion granulation. The parameters of the double-screw extruder were set as follows: the main machine rotation speed was 200r / min; the feeding rotation speed was 5r / min; the temperature of the first zone of the double-screw extruder was 180°C, the temperature of the second zone of the double-screw extruder was 190°C, the temperature of the third zone of the double-screw extruder was 200°C, the temperature of the fourth zone of the double-screw extruder was 210°C, the temperature of the fifth zone of the double-screw extruder was 220°C, the temperature of the sixth zone of the double-screw extruder was 230°C, and the temperature of the head of the double-screw extruder was 230°C. After extrusion, cooling, air-drying and entering the granulator, a graphene-carbon fiber polypropylene composite functional masterbatch was obtained.

[0112] Comparative Example 6

[0113] (1) 15g of graphene and 10g of hexadecanoic acid amide propyl trimethyl ammonium chloride were added into 100ml of n-hexane, and ultrasonic dispersion was carried out for 1-2h to obtain a modified graphene dispersion;

[0114] (2) The high-pressure polymerization kettle was vacuumed at 60°C, and then filled with propylene gas to normal pressure. Then 5L of n-hexane, 100ml of tri-n-butyl aluminum solution (solvent: 2mol / L n-heptane solution), 1mmol of diphenyl dimethoxysilane, 0.5g of TiCl4 / BuMgCl and the modified graphene dispersion prepared in step (1) were sequentially added. Then propylene was continuously fed to increase the pressure to 0.6MPa, and the reaction was carried out at 60°C for 0.3h. Then the propylene feeding was stopped, and 10% acid alcohol solution was added to terminate the reaction. The reaction product was washed with ethanol and deionized water for several times, and then dried under vacuum at 60°C to obtain a graphene-polypropylene composite material.

[0115] (3) 845g of the graphene-polypropylene composite material prepared in step (2), 150g of carbon fiber and 5g of antioxidant 1010 were respectively added into a high-speed mixer and uniformly mixed.

[0116] (4) The double screw extruder is used for extrusion granulation, and the parameters of the double screw extruder are set as follows: the main machine speed is 200 r / min; the feeding speed is 5 r / min; the temperature of the first zone of the double screw extruder is 180℃, the temperature of the second zone of the double screw extruder is 190℃, the temperature of the third zone of the double screw extruder is 200℃, the temperature of the fourth zone of the double screw extruder is 210℃, the temperature of the fifth zone of the double screw extruder is 220℃, the temperature of the sixth zone of the double screw extruder is 230℃, and the temperature of the head of the double screw extruder is 230℃. After extrusion, cooling, air drying, and entering the granulator for granulation, the graphene-carbon fiber polypropylene composite functional master batch is obtained.

[0117] Test Example 1

[0118] The performance of the master batches obtained in Examples 1 to 5 and Comparative Examples 1 to 6 is tested in this test example, and the test method includes:

[0119] 1. Mechanical properties

[0120] The tensile strength is tested according to GB / T1040-2006, and the tensile rate is 50 mm / min;

[0121] The bending strength is tested according to GB / T9341-2008, and the rate is 20 mm / min;

[0122] The notched impact strength is tested according to GB / T1843-2008, the pendulum hammer specification is 2.75J, and the sample has a V-shaped notch.

[0123] 2. Conductive properties

[0124] The resistivity of the master batch injection molded part is tested by a high resistance instrument, and the test result is the average value of three tests. The conductivity of the master batch injection molded part is obtained by formula conversion (the resistivity and the conductivity are inversely related).

[0125] 3. Thermal conductivity

[0126] The thermal conductivity coefficient of the prepared master batch injection molded part is analyzed and characterized by a hot wire method, and the test result is the average value of three tests.

[0127] The test results by the above detection methods are shown in Table 1 as follows:

[0128] Table 1:

[0129]

[0130] In the present application, the material for preparing the master batch in Example 1 is graphene / carbon fiber polypropylene composite material; the material for preparing the master batch in Comparative Example 1 is polypropylene; the material for preparing the master batch in Comparative Example 2 is graphene / polypropylene composite material, the material for preparing the master batch in Comparative Example 3 is carbon fiber / polypropylene composite material, and the material for preparing the master batch in Comparative Example 4 is physically mixed graphene / carbon fiber polypropylene composite material, and the test results show that:

[0131] The tensile strength of Comparative Example 1 is 32.5 MPa, and the tensile strength of Comparative Example 2 is 43.3 MPa, that is, the tensile strength of polypropylene is enhanced by adding graphene and uniformly dispersing the graphene. The tensile strength of Comparative Example 3 is 44.7 MPa, that is, the tensile strength of polypropylene is enhanced by adding carbon fiber. The tensile strength of Comparative Example 4 is 52.4 MPa, that is, the tensile strength of polypropylene can be further enhanced by simultaneously adding graphene and carbon fiber.

[0132] The material for preparing the master batch in Example 1 is graphene / carbon fiber polypropylene composite material, and the tensile strength of Example 1 reaches 58.3 MPa. The difference between Example 1 and Comparative Example 4 is that graphene is added in the polymerization process of polypropylene in Example 1, the graphene plays a role of nucleating agent to promote the crystallization of polypropylene, and meanwhile, the graphene can be uniformly dispersed in polypropylene, while in Comparative Example 4, the graphene is simply physically mixed, the graphene is not uniformly dispersed, and the enhancement effect on the mechanical properties of polypropylene is small. Similarly, the bending strength and impact strength also show the same law.

[0133] In addition, the electrical conductivity of Comparative Example 1 is very low, only 2.7 x 10 -13 S / m; the electrical conductivity of Comparative Example 2 is 3.9 x 10 - 6 S / m; that is, the electrical conductivity of polypropylene is enhanced by adding graphene and uniformly dispersing the graphene. The electrical conductivity of Comparative Example 3 is 4.1 x 10 -3 S / m, that is, the electrical conductivity of polypropylene is obviously enhanced by adding carbon fiber.

[0134] The electrical conductivity of Comparative Example 4 is 5.8 x 10 -2 S / m, that is, after simultaneously adding graphene and carbon fiber, the graphene and carbon fiber are connected with each other to form a conductive network, the electrical conductivity is increased to the order of 10 -2 S / m, and the electrical conductivity is greatly enhanced. In addition, the electrical conductivity of Example 1 and Comparative Example 4 is not much different, and the test results show that the electrical conductivity is mainly positively correlated with the addition amount of graphene and carbon fiber.

[0135] In the present application, the thermal conductivity of Comparative Example 1 is 0.20 W / m·K; the thermal conductivity of Comparative Example 2 is 0.43 W / m·K, that is, by adding graphene, and the uniform dispersion of graphene enhances the thermal conductivity of the polypropylene. The thermal conductivity of Comparative Example 3 is 0.92 W / m·K, that is, by adding carbon fibers, the thermal conductivity of the polypropylene is obviously enhanced.

[0136] The thermal conductivity of Comparative Example 4 is 4.26 W / m·K, and the thermal conductivity of Example 1 is 4.31 W / m·K; that is, after adding graphene and carbon fibers at the same time, the graphene and carbon fibers are connected to each other to form a network of heat dissipation channels, and the thermal conductivity increases to 4.31 W / m·K, which is 20 times higher than that of pure polypropylene, and the thermal conductivity is greatly improved. The thermal conductivity of Example 1 and Comparative Example 4 is not much different, and from the test results, the thermal conductivity is mainly positively correlated with the amount of graphene and carbon fibers added.

[0137] Compared with Example 1, the amount of graphene added in Example 2 is less, and the mechanical property enhancement effect of the master batch is relatively poor. In addition, compared with Example 1, the amount of graphene added in Example 3 is more, but the mechanical property enhancement effect of the master batch is also relatively poor, that is, too much graphene will lead to graphene agglomeration, and the mechanical property enhancement effect will be relatively poor.

[0138] Compared with Example 1, the amount of carbon fibers added in Example 4 is less, and the mechanical property enhancement effect of the master batch is relatively poor. In addition, compared with Example 1, the amount of carbon fibers added in Example 5 is more, but the mechanical property enhancement effect of the master batch is slightly lower than that of Example 1, that is, with the increase of the amount of carbon fibers added, the mechanical property will first increase and then tend to be stable.

[0139] In addition, the electrical conductivity and thermal conductivity are positively correlated with the amount of graphene and carbon fibers added, and the electrical conductivity and thermal conductivity improve with the increase of the amount added.

[0140] Compared with Example 1, no surfactant is added in Comparative Example 5, the mechanical property of Comparative Example 5 is reduced, and the difference in electrical conductivity and thermal conductivity is not large, which is because no surfactant is added in Comparative Example 5, the dispersibility of graphene is poor, and it is easy to agglomerate, and the increasing effect on polypropylene is relatively weak.

[0141] Compared with Example 1, no silane coupling agent is added in Comparative Example 6, the mechanical property of Comparative Example 6 is relatively weak, and the difference in electrical conductivity and thermal conductivity is not large, which is because no silane coupling agent is added in Comparative Example 6, the interfacial bonding force between graphene and polypropylene is weak, resulting in relatively poor enhancement effect of graphene on polypropylene.

[0142] The above merely describes the preferred embodiments of the present application, and is not intended to limit the present application in any form. Although the present application has been disclosed with the preferred embodiments as above, it is not intended to limit the present application. Any person skilled in the art can make some changes or modifications to the above-mentioned technical content with some equivalent embodiments of the equivalent changes, without departing from the technical solution of the present application. Any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present application, without departing from the technical solution of the present application, still belongs to the scope of the present application.

Claims

1. A method for preparing a graphene-carbon fiber polypropylene composite master batch, characterized in that: 1) mixing graphene, a surfactant and an organic solvent to obtain a modified graphene dispersion, wherein the surfactant is hexadecanoic acid amidopropyl trimethylammonium chloride, and the mass ratio of graphene to surfactant is 1.5:1; 2) placing the modified graphene dispersion, an organic solvent, an alkyl aluminum compound solution, a silane coupling agent and a catalyst in a high-pressure polymerization kettle, and performing a reaction under an atmosphere of propylene to obtain a graphene-polypropylene composite; 3) mixing the graphene-polypropylene composite, carbon fiber and an antioxidant, extruding through a double-screw extruder and granulating to obtain the graphene-carbon fiber polypropylene composite master batch; in the step 1), the organic solvent is selected from one or more of n-pentane, n-hexane, n-heptane, n-octane and n-decane; in the step 2), the high-pressure polymerization kettle is first vacuumed, then propylene gas is filled to the normal pressure state, and then the organic solvent, the alkyl aluminum compound solution, the silane coupling agent, the catalyst and the modified graphene dispersion are sequentially added, and then the reaction is performed after the high-pressure polymerization kettle is continuously filled with propylene gas to a pressure of 0.2-0.8 Mpa; in the step 2), the high-pressure polymerization kettle is vacuumed at 40-80℃; in the step 2), the solute alkyl aluminum compound in the alkyl aluminum compound solution includes one or more of triethyl aluminum, triisobutyl aluminum and tri-n-butyl aluminum, and the solvent includes one or more of n-pentane, n-hexane, n-heptane, n-octane and n-decane; in the step 2), the concentration of the alkyl aluminum compound solution is 1-3 mol / L; in the step 2), the addition amount of the alkyl aluminum compound solution is 0.1-50 mmol / kg of propylene; in the step 2), the silane coupling agent includes one or more of methoxysilane, aminosilane, vinylsilane and methacryloyloxysilane; in the step 2), the addition amount of the silane coupling agent is 0.1-3 mmol / g of catalyst; in the step 2), the catalyst includes one or both of a Ziegler-Natta catalyst and a metallocene catalyst; the Ziegler-Natta catalyst is selected from one or more of MgCl2 / TiCl4, TiCl4 / BuMgCl, TiCl4 / AlEt3, SiO2 / TiCl4, Avant Z-N catalyst, SHAC 330 catalyst, RCE02P polypropylene catalyst and LYNX2000 series catalyst; the metallocene catalyst is selected from one or more of APE1S metallocene catalyst, PMP-01 supported metallocene polypropylene catalyst, bridged zirconocene catalyst, bridged fluorenyl zirconocene catalyst, bridged monofluorenyl monocyclopentadienyl zirconocene metal compound catalyst, CGC catalyst and Avant M series catalyst; in the step 1), the graphene is in a powder form, and the flake diameter is less than 200 um. ​ ​ ​ ​ ​ 2. The preparation method of the graphene-carbon fiber polypropylene composite master batch according to claim 1, characterized in that: ​ 3. The preparation method of the graphene-carbon fiber polypropylene composite master batch according to claim 1 or 2, characterized in that: ​ 4. The preparation method of the graphene-carbon fiber polypropylene composite master batch according to any one of claims 1-3, characterized in that: ​ 5. The preparation method of the graphene-carbon fiber polypropylene composite master batch according to any one of claims 1-4, characterized in that: ​ 6. The preparation method of the graphene-carbon fiber polypropylene composite master batch according to claim 1, characterized in that: ​ 7. The method for preparing a graphene-carbon fiber-polypropylene composite masterbatch according to claim 6, characterized in that: ​ 8. The preparation method of the graphene-carbon fiber polypropylene composite master batch according to claim 1, characterized in that: ​ 9. The method for preparing a graphene-carbon fiber-polypropylene composite masterbatch according to claim 8, characterized in that: ​ ​ 10. The method for preparing a graphene-carbon fiber polypropylene composite master batch according to claim 1, characterized in that: ​ 11. The method for preparing a graphene-carbon fiber polypropylene composite master batch according to claim 1, characterized in that: The graphene in the step 1) is selected from one or more of pure graphene, graphene oxide, reduced graphene oxide, and organically modified graphene.

12. The method for preparing a graphene-carbon fiber polypropylene composite master batch according to claim 1, characterized in that: The mass percentage concentration of graphene in the modified graphene dispersion liquid in the step 1) is 5-50%.

13. The method for preparing a graphene-carbon fiber polypropylene composite master batch according to claim 1, characterized in that: The mass fractions of the components in the graphene-carbon fiber-polypropylene composite material in the step 3) are as follows: Graphene-polypropylene composite material 60%-95% Carbon fiber 5%-40% Antioxidant 0.1%-1%.

14. The method for preparing a graphene-carbon fiber polypropylene composite master batch according to claim 1, characterized in that: The parameters of the twin-screw extruder in the step 3) are set as follows: the main machine rotation speed is 100-300 r / min, the feeding rotation speed is 3-10 r / min, and the extrusion granulation temperature is 180-240 DEG C.

15. The method for preparing a graphene-carbon fiber polypropylene composite masterbatch according to claim 14, characterized in that: The temperature of the twin-screw extruder in the step 3) is set as follows: the temperature of the first zone is 180-190 DEG C, the temperature of the second zone is 190-200 DEG C, the temperature of the third zone is 200-210 DEG C, the temperature of the fourth zone is 210-220 DEG C, the temperature of the fifth zone is 220-230 DEG C, the temperature of the sixth zone is 230-240 DEG C, and the temperature of the head is 230-240 DEG C.

16. The method for preparing a graphene-carbon fiber polypropylene composite master batch according to claim 1, characterized in that: The reaction is terminated by adding an acid alcohol solution into the system in the step 2).

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