1. A method for preparing a porous graphene honeycomb core material, which is characterized by comprising the following steps:

(1) mixing and ultrasonically treating the stripped graphene nanosheets, polymethyl methacrylate, a high polymer material and an organic solvent to obtain an electrostatic spinning solution;

(2) carrying out electrostatic spinning treatment by adopting the electrostatic spinning solution so as to obtain a graphene fiber membrane;

(3) mixing the graphene fiber film and a thermoplastic material, and extruding and granulating to obtain a thermoplastic granule with graphene sheet layers;

(4) and extruding, honeycomb forming and cutting the thermoplastic granules to obtain the porous graphene honeycomb core material.

2. The method according to claim 1, wherein in the step (1), the graphene nanoplate, the polymethyl methacrylate, the polymer material and the organic solvent are mixed, magnetically stirred for 6-12 hours, then subjected to ultrasonic treatment for 2-4 hours,

optionally, the magnetic stirring is carried out at room temperature, the ultrasonic treatment is carried out under the condition of a water bath at 15-25 ℃,

optionally, in the step (1), the polymer material is at least one selected from polyacrylonitrile, polyethylene, polypropylene, polystyrene and polyvinyl chloride,

optionally, in the step (1), the organic solvent is at least one selected from the group consisting of dimethyl sulfoxide, ethanol, acetone, dimethylformamide, ethylene glycol, n-butanol and isopropanol,

optionally, in the step (1), the electrospinning solution comprises 0.2-2 wt% of graphene nanosheets, 2-10 wt% of polymethyl methacrylate, 10-40 wt% of high polymer materials and the balance of organic solvents.

3. The method according to claim 1, wherein in the step (2), the receiving distance between the nozzle and the receiver of the electrostatic spinning treatment is 20-30 cm, the flow rate of the spinning solution is 0.2-2 ml/h, the voltage is 10-20 kV,

optionally, the electrostatic spinning receiving device is a roller, the roller rotating speed is 1000-3000 r/min, and the heating temperature of the receiver is 28-32 ℃.

4. The method according to claim 1, wherein in the step (3), the temperature of the extrusion granulation is 160-190 ℃,

optionally, in step (3), the thermoplastic material is at least one selected from polypropylene, polycarbonate and polyethylene terephthalate,

optionally, in the step (3), the mass ratio of the graphene fiber membrane to the thermoplastic material is (10-20): 100.

5. The method according to claim 1, wherein in the step (4), the thermoplastic granules are extruded and dried to form a honeycomb stack, and then a heating wire cutting process is performed to obtain the porous graphene honeycomb core material.

6. A porous graphene honeycomb core material, characterized by being prepared by the method of any one of claims 1 to 5.

7. The method of preparing a porous graphene honeycomb core material according to any one of claims 1 to 5 and/or the use of the porous graphene honeycomb core material according to claim 6 in the fields of automobiles, high-speed rail and aerospace.

8. A vehicle, characterized by comprising the porous graphene honeycomb core material prepared by the method of any one of claims 1 to 5.

9. The vehicle of claim 8, comprising an automobile and a high-speed rail.

10. An aircraft, characterized by comprising the porous graphene honeycomb core prepared by the method of any one of claims 1-5.

Background

The current honeycomb core material mainly comprises paper honeycombs, aluminum honeycombs and plastic honeycomb materials, but the paper honeycombs are easy to wet and wet, the aluminum honeycombs are high in price, poor in sound insulation effect and poor in corrosivity, and the plastic honeycomb materials successfully solve the problems and are widely applied to the fields of automobiles, high-speed rails and airplanes. In the face of increasingly stringent regulatory requirements, light weight is being sought in the fields of automobiles, high-speed rails, aerospace and the like. How to further reduce the density of the plastic honeycomb and improve the performance of the plastic honeycomb simultaneously becomes an important development direction in the field of composite materials. The existing plastic honeycomb material mainly comprises PP, PC, PET and the like, and although the honeycomb material is widely used, the honeycomb material has single component, the density cannot be further reduced, and the heat insulation performance needs to be further improved, because noise and electromagnetic wave pollution are also core problems concerned. The key to the reduction in density and performance of the composite is the honeycomb core, and it is therefore highly desirable to provide a low density, high performance thermoplastic honeycomb.

Disclosure of Invention

The present invention is directed to solving, at least to some extent, one of the technical problems in the related art. Therefore, the invention aims to provide a porous graphene honeycomb core material, and a preparation method and application thereof. According to the method, PMMA and graphene are simultaneously applied to thermoplastic plastic honeycomb granules, so that the preparation of the graphene honeycomb core material with a porous structure can be realized, the density of the honeycomb core can be reduced due to porosity, the purposes of saving energy, reducing emission and improving performance are achieved, and meanwhile, the mechanical property, the thermal stability and the heat preservation property can be enhanced due to the addition of the graphene, the sound insulation and heat insulation properties can be improved, and the electromagnetic shielding effect is given to the honeycomb material.

According to a first aspect of the invention, a method of preparing a porous graphene honeycomb core is provided. According to an embodiment of the invention, the method comprises:

(1) mixing and ultrasonically treating the stripped graphene nanosheets, polymethyl methacrylate, a high polymer material and an organic solvent to obtain an electrostatic spinning solution;

(2) carrying out electrostatic spinning treatment by adopting the electrostatic spinning solution so as to obtain a graphene fiber membrane;

(3) mixing the graphene fiber film and a thermoplastic material, and extruding and granulating to obtain a thermoplastic granule with graphene sheet layers;

(4) and extruding, honeycomb forming and cutting the thermoplastic granules to obtain the porous graphene honeycomb core material.

According to the method for preparing the porous graphene honeycomb core material, on one hand, the mechanical property, the thermal stability and the thermal insulation property are enhanced by adding the graphene with the three-dimensional structure into the existing honeycomb core material, and meanwhile, the sound insulation and heat insulation properties are improved, and the electromagnetic shielding effect is given to the honeycomb core; on the other hand, through porous design, the aim of light weight is fulfilled, and meanwhile, the dispersibility of graphene in the composite material can be enhanced; in addition, the nanofiber film prepared by the electrostatic spinning method is uniform in dispersion, large in specific surface area, adjustable in graphene content and stable in quality of the honeycomb core material. In conclusion, the method is simple in process and suitable for large-scale production and application, compared with the existing honeycomb core, the porous graphene honeycomb core material prepared by the method is lower in density and better in performance, is green and recyclable, can be heated and compounded with a thermoplastic surface skin through a rolling device or a non-woven fabric, and then is pressed and molded with glass fiber reinforced plastic or other surface layers by using an adhesive to prepare the thermoplastic/thermosetting porous graphene composite honeycomb sandwich composite material, and is suitable for the fields of automobiles, high-speed rail carriages or airplanes and the like.

In addition, the method for preparing the porous graphene honeycomb core material according to the above embodiment of the present invention may further have the following additional technical features:

in some embodiments of the invention, in the step (1), the graphene nanoplate, the polymethyl methacrylate, the polymer material and the organic solvent are mixed, magnetically stirred for 6-12 hours, and then subjected to ultrasonic treatment for 2-4 hours.

In some embodiments of the invention, in the step (1), the magnetic stirring is performed at room temperature, and the ultrasonic treatment is performed in a water bath at 15-25 ℃.

In some embodiments of the present invention, in the step (1), the polymer material is at least one selected from polyacrylonitrile, polyethylene, polypropylene, polystyrene and polyvinyl chloride.

In some embodiments of the present invention, in the step (1), the organic solvent is at least one selected from the group consisting of dimethyl sulfoxide, ethanol, acetone, dimethylformamide, ethylene glycol, n-butanol and isopropanol.

In some embodiments of the invention, in the step (1), the electrospinning solution comprises 0.2-2 wt% of graphene nanosheets, 2-10 wt% of polymethyl methacrylate, 10-40 wt% of a high molecular material and the balance of an organic solvent.

In some embodiments of the invention, in the step (2), the receiving distance between the spray head and the receiver of the electrostatic spinning treatment is 20-30 cm, the flow rate of the spinning solution is 0.2-2 ml/h, and the voltage is 10-20 kV.

In some embodiments of the invention, in the step (2), the receiving device of the electrostatic spinning is a roller, the rotating speed of the roller is 1000-3000 r/min, and the heating temperature of the receiver is 28-32 ℃.

In some embodiments of the present invention, in the step (3), the temperature of the extrusion granulation is 160 to 190 ℃.

In some embodiments of the invention, in step (3), the thermoplastic material is at least one selected from the group consisting of polypropylene, polycarbonate, and polyethylene terephthalate.

In some embodiments of the invention, in the step (3), the mass ratio of the graphene fiber membrane to the thermoplastic material is (10-20): 100.

In some embodiments of the present invention, in the step (4), the thermoplastic pellets are extruded and dried to form a honeycomb stack, and then a heating wire cutting process is performed, so as to obtain the porous graphene honeycomb core material.

According to a second aspect of the invention, the invention provides a porous graphene honeycomb core material. According to the embodiment of the invention, the porous graphene honeycomb core material is prepared by adopting the method for preparing the porous graphene honeycomb core material. Compared with the existing honeycomb core, the porous graphene honeycomb core material is lower in density, better in mechanical property, thermal stability, heat retaining property and sound and heat insulation property, and has an electromagnetic shielding effect, and green and recyclable, can be heated and compounded with a thermoplastic face skin through rolling equipment or a non-woven fabric, and then is subjected to pressure forming with glass fiber reinforced plastic or other surface layers by using an adhesive to prepare a thermoplastic/thermosetting porous graphene composite honeycomb interlayer composite material, and is suitable for the fields of automobiles, high-speed rail carriages or airplanes and the like.

According to a third aspect of the invention, the invention provides the method for preparing the porous graphene honeycomb core material and/or the application of the porous graphene honeycomb core material in the fields of automobiles, high-speed rails and spaceflight. In the prior art, the porous graphene honeycomb core material or the porous graphene honeycomb core material prepared by the preparation method is used in the fields of automobiles, high-speed rails and spaceflight, and can better meet the requirements of light weight, heat preservation and insulation, noise reduction, electromagnetic wave pollution reduction and the like.

According to a fourth aspect of the present invention, a vehicle is provided. According to an embodiment of the invention, the vehicle comprises the porous graphene honeycomb core obtained by adopting the method for preparing the porous graphene honeycomb core. Compared with the prior art, the vehicle can better meet the requirements of light weight and the like.

In some embodiments of the invention, the vehicle comprises an automobile and a high-speed rail.

According to a fifth aspect of the invention, an aircraft is proposed. According to an embodiment of the invention, the aircraft comprises the porous graphene honeycomb core material obtained by adopting the method for preparing the porous graphene honeycomb core material. Compared with the prior art, the vehicle can better meet the requirements of light weight and the like.

Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.

Drawings

The above and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

fig. 1 is a flow chart of a method of making a porous graphene honeycomb core according to one embodiment of the present invention.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are illustrative and intended to be illustrative of the invention and are not to be construed as limiting the invention.

According to a first aspect of the invention, a method of preparing a porous graphene honeycomb core is provided. As shown in fig. 1, according to an embodiment of the invention, the method comprises: (1) mixing and ultrasonically treating the stripped graphene nanosheets, polymethyl methacrylate (PMMA), high polymer materials and an organic solvent to obtain an electrostatic spinning solution; (2) carrying out electrostatic spinning treatment by adopting electrostatic spinning solution so as to obtain a graphene fiber membrane; (3) mixing the graphene fiber film and a thermoplastic material, and extruding and granulating to obtain a thermoplastic granule with graphene sheet layers; (4) and extruding, honeycomb forming and cutting the thermoplastic granules to obtain the porous graphene honeycomb core material. According to the method, PMMA and graphene are simultaneously applied to thermoplastic plastic honeycomb granules, so that the preparation of the graphene honeycomb core material with a porous structure can be realized, the density of the honeycomb core can be reduced due to porosity, the purposes of saving energy, reducing emission and improving performance are achieved, and meanwhile, the mechanical property, the thermal stability and the heat preservation property can be enhanced due to the addition of the graphene, the sound insulation and heat insulation properties can be improved, and the electromagnetic shielding effect is given to the honeycomb material.

The method of preparing the porous graphene honeycomb core material according to the above embodiment of the present invention will be described in detail with reference to fig. 1.

S100, mixing and ultrasonically treating the stripped graphene nanosheets, polymethyl methacrylate, high polymer material and organic solvent to obtain electrostatic spinning solution

According to the embodiments of the present invention, in order to obtain a low-density and high-performance honeycomb core material, the inventors conceived that a graphene fiber film may be prepared in advance by an electrospinning method, and then the graphene fiber film may be mixed with a thermoplastic material to be subjected to extrusion granulation. On the basis, the peeled graphene nanosheet, the polymethyl methacrylate, the high polymer material and the organic solvent can be mixed and subjected to ultrasonic treatment to obtain the uniform and stable electrostatic spinning solution. The polymer material does not contain PMMA, the stripped graphene nanosheets are adopted to prepare the electrostatic spinning solution, so that the distribution of graphene in the spinning solution is more uniform, in addition, the polymethyl methacrylate is mainly used as a pore-forming agent, the agglomeration of the graphene is prevented, the dispersion of the graphene in a fiber film is enhanced, and the polymer material is mainly used for forming a carbon nanofiber film carrier for electrostatic spinning.

According to a specific embodiment of the present invention, the source of the exfoliated graphene nanoplatelets in the present invention is not particularly limited, and can be selected by those skilled in the art according to actual needs. For example, the exfoliated graphene nanoplatelets can be prepared from graphite or expanded graphite by a mechanical exfoliation method, a liquid-phase or gas-phase exfoliation method. In addition, the types of the polymer material and the organic solvent in the present invention are not particularly limited, and those skilled in the art can select them according to actual needs, for example, the polymer material may be preferably a thermoplastic material, such as at least one selected from polyacrylonitrile, polyethylene, polypropylene, polystyrene and polyvinyl chloride, and the inventors have found that, compared with a thermosetting material, the thermoplastic material does not generate cross-linking reaction between linear molecules and graphene when heated, and has the performance of repeated heating softening and cooling hardening in a certain temperature range, which is more beneficial to ensuring the mechanical property, processability, thermal stability and other properties of the finally prepared porous graphene honeycomb core material; the organic solvent may be at least one selected from the group consisting of dimethyl sulfoxide, ethanol, acetone, dimethylformamide, ethylene glycol, n-butanol and isopropanol.

According to another specific embodiment of the invention, when preparing the electrospinning solution, graphene nanoplatelets, polymethyl methacrylate, a polymer material and an organic solvent are mixed, magnetically stirred for 6-12 hours on a magnetic stirrer, and then placed in an ultrasonic oscillator for ultrasonic treatment for 2-4 hours, for example, the magnetic stirring time may be 6 hours, 7 hours, 8 hours, 9 hours, 10 hours, 11 hours, 12 hours, and the like, and the ultrasonic treatment time may be 2 hours, 2.5 hours, 3 hours, 3.5 hours, 4 hours, and the like, so that the uniformity and stability of the electrospinning solution can be further improved. The magnetic stirring can be carried out at room temperature, and the ultrasonic treatment can be carried out in a water bath condition at 15-25 ℃, so that the high polymer material and the graphene can be uniformly dispersed in the organic solvent, the dispersion and the non-agglomeration of the graphene are ensured, and the spinnability of the precursor is realized.

According to another embodiment of the present invention, the electrospinning solution includes 0.2 to 2 wt% of graphene nanoplate, 2 to 10 wt% of polymethyl methacrylate, 10 to 40 wt% of polymer material, and the balance of organic solvent, for example, the content of the graphene nanoplate may be 0.2 wt%, 0.5 wt%, 0.8 wt%, 1.2 wt%, 1.5 wt%, 1.8 wt%, or 2 wt%, etc., the content of the polymethyl methacrylate may be 2 wt%, 3 wt%, 4 wt%, 5 wt%, 6 wt%, 7 wt%, 8 wt%, 9 wt%, or 10 wt%, etc., the content of the polymer material may be 10 wt%, 15 wt%, 20 wt%, 25 wt%, 30 wt%, 35 wt%, or 40 wt%, etc., and the inventors found that, if the addition amount of the graphene nanoplate is too small, the effect on enhancing the performances of the composite material is not significant, and if the addition amount of the graphene nanoplate is too large, the loading capacity of graphene in the composite material is too large, and graphene with a three-dimensional structure between polymer layers is easy to be stacked again and agglomerated into graphite; if the addition amount of the polymethyl methacrylate is too small, the pore-forming rate of the fiber membrane is low, and the lightweight effect is not obvious, and if the addition amount of the polymethyl methacrylate is too large, the distribution and the content of the graphene are influenced; if the addition amount of the high polymer material is too small, the solution concentration or the molecular weight is too low, the viscosity of the spinning solution is insufficient, the spinnability of the precursor is affected, so that the electrostatic spinning is easy to generate a bead structure due to the fact that the spinning solution is sprayed but does not form fibers, and if the addition amount of the high polymer material is too large, the viscosity of the spinning solution is too high, the dissolution is difficult, the gel is formed, and the needle head and the receiver are easy to be connected in the spinning process. According to the invention, by controlling the electrostatic spinning solution to be the raw material ratio, the lightweight effect of the nanofiber membrane can be obviously improved, and the performances such as mechanics, heat preservation and the like can be improved.

S200, carrying out electrostatic spinning treatment by adopting electrostatic spinning solution to obtain the graphene fiber membrane

According to the embodiment of the invention, the graphene fiber membrane prepared by the electrostatic spinning method has the advantages of uniform dispersion of all components, large specific surface area, adjustable graphene content and stable quality of the finally prepared honeycomb core material. The addition amounts of graphene and PMMA can be regulated and controlled by controlling the composition of the electrostatic spinning solution, the fiber particle size of the graphene fiber film is controlled by controlling the technological parameters of electrostatic spinning, and the graphene nanofiber film is preferably prepared by electrostatic spinning treatment.

According to an embodiment of the present invention, when preparing the graphene fiber membrane, the receiving device for electrostatic spinning may be a roller, and the heating temperature of the receiver may be 28 to 32 ℃, for example, 28 ℃, 29 ℃, 30 ℃, 31 ℃ or 32 ℃, etc., and the purpose of heating is to ensure that the small molecule solvent is sufficiently evaporated, but the inventors found that if the heating temperature is too low, a fused fiber may be formed; however, if the heating temperature is too high, the polymer may be crystallized, and the above problem can be effectively avoided by controlling the heating temperature of the receiver to the above range. The distance between the nozzle and the receiver in the electrospinning process may be 20 to 30cm, for example, 20cm, 22cm, 24cm, 26cm, 28cm, or 30cm, the flow rate of the spinning solution may be 0.2 to 2ml/h, for example, 0.2ml/h, 0.5ml/h, 0.8ml/h, 1.2ml/h, 1.5ml/h, 1.8ml/h, or 2ml/h, the roll rotation speed may be 1000 to 3000 revolutions per minute (rpm), for example, 1000rpm, 1400rpm, 1800rpm, 2200rpm, 2600rpm, or 3000rpm, and the voltage may be 10 to 20kV, for example, 10kV, 12kV, 14kV, 16kV, 18kV, or 10 kV. The inventors found that changing the take-up distance, the flow rate of the spinning solution, the rotation speed of the rolls, and the voltage range affects the spinning effect of the fiber film, and specifically, if the take-up distance is too short, which easily causes insufficient evaporation of the solvent, fused fibers may be formed, and if the distance is too long, fibers cannot be taken up on the receiver; with the increase of the spinning speed, the diameter of the prepared nano fiber can be gradually increased, and even bead-shaped fibers are formed; if the roller rotating speed is too high, the fiber diameter is too small, graphene cannot be coated on the fibers, and if the roller rotating speed is too low, the fiber diameter is too large, and the excellent performance of the nano-scale fiber membrane cannot be obtained; when the spinning voltage range is 10-20 kV, the prepared nanofiber is continuous and has a smooth surface, the diameter of the nanofiber is reduced along with the increase of the spinning voltage, the drawing and splitting of spinning solution are hindered when the voltage is low, the diameter of the formed nanofiber is large, the electric field intensity is too large when the voltage is too high, the diameter of the fiber is increased, the uniformity is poor, beaded or beaded nanofibers are caused, and the electric spark phenomenon can occur. According to the invention, by controlling the receiving distance, the flow rate of the spinning solution, the rotating speed of the roller and the voltage to be in the ranges, the smooth and uniform graphene-loaded nanofiber membrane can be prepared.

S300, mixing the graphene fiber film and the thermoplastic material, extruding and granulating to obtain the thermoplastic granules with the graphene sheet layer

According to the embodiment of the invention, the graphene fiber film and the thermoplastic honeycomb core material particles can be mixed by a double-screw extruder and then extruded and granulated, so that the thermoplastic honeycomb core granules with graphene sheet layer materials are obtained, and the granules simultaneously contain a porous structure and graphene sheets.

According to an embodiment of the present invention, the temperature when the graphene fiber film and the thermoplastic material are mixed and extruded and granulated may be 160 to 190 ℃, for example, 160 ℃, 165 ℃, 170 ℃, 175 ℃, 180 ℃, 185 ℃, or 190 ℃, so that the graphene honeycomb core material having uniform particle size and stable product quality can be obtained.

According to another embodiment of the present invention, the kind of the thermoplastic material is not particularly limited, and those skilled in the art can select the thermoplastic material according to actual needs, for example, the thermoplastic material may be at least one selected from polypropylene, polycarbonate and polyethylene terephthalate, and compared with a thermosetting material, the thermoplastic material does not generate cross-linking reaction between linear molecules and graphene when heated, and has the performance of repeated heating softening and cooling hardening in a certain temperature range, which is more beneficial to ensure the comprehensive performance of the finally prepared porous graphene honeycomb core material.

According to another embodiment of the invention, the mass ratio of the graphene fiber film to the thermoplastic material can be (10-20): 100, for example, 10/100, 11/100, 12/100, 13/100, 14/100, 15/100, 16/100, 17/100, 18/100, 19/100 or 20/100, and the inventors found that the mass ratio of the graphene fiber film to the thermoplastic material affects the formability and physicochemical properties of the core material, and if the mass ratio of the graphene fiber film to the thermoplastic material is too small, the properties of the composite material cannot be improved; if the mass ratio of the graphene fiber membrane to the thermoplastic material is too large, the loading of graphene in the composite material is too large, and graphene with a three-dimensional structure between polymer layers is easy to be stacked again and agglomerated into graphite. According to the invention, the porous graphene honeycomb core granules with low density and high performance can be obtained more favorably by controlling the mass ratio range of the graphene fiber membrane and the thermoplastic material.

S400, extruding, honeycomb forming and cutting the thermoplastic granules to obtain the porous graphene honeycomb core material

According to the embodiment of the invention, the thermoplastic granules obtained in the above steps can be extruded and dried to form a honeycomb stack, and then the heating wire cutting treatment is carried out to obtain the porous honeycomb core material containing graphene. The diameter of the honeycomb and the thickness of the core plate can be adjusted according to actual needs; the prepared porous graphene honeycomb core material and the thermoplastic surface skin can be heated and compounded through rolling equipment; or the composite material can be heated and compounded with non-woven fabrics and then is pressed and molded with glass fiber reinforced plastic or other surface layers by using an adhesive to prepare the thermoplastic/thermosetting porous graphene composite honeycomb sandwich composite material, and the composite material can be widely applied to the fields of automobiles, high-speed rail carriages or airplanes and the like.

In summary, according to the method for preparing the porous graphene honeycomb core material in the embodiment of the invention, on one hand, the graphene with a three-dimensional structure is added into the existing honeycomb core material to enhance the mechanical property, the thermal stability and the thermal insulation property, and simultaneously, the sound insulation and heat insulation properties are improved, and the electromagnetic shielding effect is given to the honeycomb core; on the other hand, through porous design, the aim of light weight is fulfilled, and meanwhile, the dispersibility of graphene in the composite material can be enhanced; in addition, the nanofiber film prepared by the electrostatic spinning method is uniform in dispersion, large in specific surface area, adjustable in graphene content and stable in quality of the honeycomb core material. In conclusion, the method is simple in process and suitable for large-scale production and application, compared with the existing honeycomb core, the porous graphene honeycomb core material prepared by the method is lower in density and better in performance, is green and recyclable, can be heated and compounded with a thermoplastic surface skin through a rolling device or a non-woven fabric, and then is pressed and molded with glass fiber reinforced plastic or other surface layers by using an adhesive to prepare the thermoplastic/thermosetting porous graphene composite honeycomb sandwich composite material, and is suitable for the fields of automobiles, high-speed rail carriages or airplanes and the like.

According to a second aspect of the invention, the invention provides a porous graphene honeycomb core material. According to the embodiment of the invention, the porous graphene honeycomb core material is prepared by adopting the method for preparing the porous graphene honeycomb core material. Compared with the existing honeycomb core, the porous graphene honeycomb core material is lower in density, better in mechanical property, thermal stability, heat retaining property and sound and heat insulation property, and has an electromagnetic shielding effect, and green and recyclable, can be heated and compounded with a thermoplastic face skin through rolling equipment or a non-woven fabric, and then is subjected to pressure forming with glass fiber reinforced plastic or other surface layers by using an adhesive to prepare a thermoplastic/thermosetting porous graphene composite honeycomb interlayer composite material, and is suitable for the fields of automobiles, high-speed rail carriages or airplanes and the like. It should be noted that the features and effects described for the method for preparing the porous graphene honeycomb core material are also applicable to the porous graphene honeycomb core material, and are not described in detail herein.

According to a third aspect of the invention, the invention provides the method for preparing the porous graphene honeycomb core material and/or the application of the porous graphene honeycomb core material in the fields of automobiles, high-speed rails and spaceflight. In the prior art, the porous graphene honeycomb core material or the porous graphene honeycomb core material prepared by the preparation method is used in the fields of automobiles, high-speed rails and spaceflight, and can better meet the requirements of light weight, heat preservation and insulation, noise reduction, electromagnetic wave pollution reduction and the like. It should be noted that the characteristics and effects described for the porous graphene honeycomb core material and the method for preparing the porous graphene honeycomb core material are also applicable to the application of the porous graphene honeycomb core material in the fields of automobiles, high-speed rails and aerospace, and are not described in detail here.

According to a fourth aspect of the present invention, a vehicle is provided. According to an embodiment of the invention, the vehicle comprises the porous graphene honeycomb core obtained by adopting the method for preparing the porous graphene honeycomb core. Compared with the prior art, the vehicle can better meet the requirements of light weight, noise reduction and the like. It should be noted that the type of the vehicle in the present invention is not particularly limited, and those skilled in the art can select the vehicle according to actual needs, for example, the vehicle may be an automobile or a high-speed rail. In addition, it should be noted that the features and effects described for the method for preparing the porous graphene honeycomb core material are also applicable to the vehicle, and are not repeated herein.

According to a fifth aspect of the invention, an aircraft is proposed. According to an embodiment of the invention, the aircraft comprises the porous graphene honeycomb core material obtained by adopting the method for preparing the porous graphene honeycomb core material. Compared with the prior art, the vehicle can better meet the requirements of light weight and the like. It should be noted that the features and effects described for the above method for preparing the porous graphene honeycomb core material are also applicable to the aircraft, and are not described in detail here.

The scheme of the invention will be explained with reference to the examples. It will be appreciated by those skilled in the art that the following examples are illustrative of the invention only and should not be taken as limiting the scope of the invention. The examples, where specific techniques or conditions are not indicated, are to be construed according to the techniques or conditions described in the literature in the art or according to the product specifications. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products commercially available.

Example 1

(1) Adding a small amount of stripped graphene nanosheets into an organic solution containing polymethyl methacrylate and other macromolecules, stirring for 8 hours on a magnetic stirrer at room temperature, putting the magnetic stirrer into an ultrasonic oscillator, and carrying out ultrasonic treatment for 3 hours in a water bath condition of 20 ℃ to obtain a uniform and stable electrostatic spinning solution, wherein the adopted macromolecular material is polyacrylonitrile, the organic solvent is dimethyl sulfoxide, and the electrostatic spinning solution comprises 1 wt% of graphene nanosheets, 6 wt% of polymethyl methacrylate and 25 wt% of macromolecular materials.

(2) Carrying out electrostatic spinning treatment by using electrostatic spinning solution to obtain a graphene fiber membrane, wherein a receiving device is a roller, a receiver is heated to 30 ℃, the receiving distance between a spray head and the receiver is 25cm, the flow rate is 1.0ml/h, the rotating speed of the roller is 2000rpm, and the voltage is 15 kV;

(3) mixing a graphene fiber film and a polypropylene thermoplastic material in a mass ratio of 15:100 by using a double-screw extruder, and then extruding and granulating to obtain a thermoplastic granule with a graphene sheet layer, wherein the extrusion temperature is set to be 170 ℃;

(4) and extruding and drying the thermoplastic granules to form a honeycomb stack, and then carrying out electric heating wire cutting treatment to obtain the porous graphene honeycomb core material.

Example 2

(1) Adding a small amount of stripped graphene nanosheets into an organic solution containing polymethyl methacrylate and other thermoplastic macromolecules, stirring for 6 hours on a magnetic stirrer at room temperature, placing the magnetic stirrer into an ultrasonic oscillator, and performing ultrasonic treatment for 2 hours in a water bath condition at 25 ℃ to obtain a uniform and stable electrostatic spinning solution, wherein the adopted macromolecular material is polyethylene, the organic solvent is ethylene glycol, and the electrostatic spinning solution comprises 2 wt% of graphene nanosheets, 2 wt% of polymethyl methacrylate and 40 wt% of macromolecular material.

(2) Carrying out electrostatic spinning treatment by using electrostatic spinning solution to obtain a graphene fiber membrane, wherein a receiving device is a roller, a receiver is heated to 28 ℃, the receiving distance between a spray head and the receiver is 30cm, the flow rate is 0.2ml/h, the rotating speed of the roller is 2000rpm, and the voltage is 20 kV;

(3) mixing a graphene fiber film and a polypropylene thermoplastic material in a mass ratio of 10:100 by using a double-screw extruder, and then extruding and granulating to obtain a thermoplastic granule with a graphene sheet layer, wherein the extrusion temperature is set to be 160 ℃;

(4) and extruding and drying the thermoplastic granules to form a honeycomb stack, and then carrying out electric heating wire cutting treatment to obtain the porous graphene honeycomb core material.

Example 3

(1) Adding a small amount of stripped graphene nanosheets into an organic solution containing polymethyl methacrylate and other macromolecules, stirring for 12 hours on a magnetic stirrer at room temperature, putting the magnetic stirrer into an ultrasonic oscillator, and carrying out ultrasonic treatment for 4 hours in a water bath condition at 15 ℃ to obtain a uniform and stable electrostatic spinning solution, wherein the adopted high polymer material is polystyrene, the organic solvent is dimethylformamide, and the electrostatic spinning solution comprises 0.2 wt% of graphene nanosheets, 10 wt% of polymethyl methacrylate and 10 wt% of high polymer material.

(2) Carrying out electrostatic spinning treatment by using electrostatic spinning solution to obtain a graphene fiber membrane, wherein a receiving device is a roller, a receiver is heated to 32 ℃, the receiving distance between a spray head and the receiver is 20cm, the flow rate is 2.0ml/h, the rotating speed of the roller is 2000rpm, and the voltage is 10 kV;

(3) mixing a graphene fiber film and a polypropylene thermoplastic material in a mass ratio of 20:100 by using a double-screw extruder, and then extruding and granulating to obtain a thermoplastic granule with a graphene sheet layer, wherein the extrusion temperature is set to be 190 ℃;

(4) and extruding and drying the thermoplastic granules to form a honeycomb stack, and then carrying out electric heating wire cutting treatment to obtain the porous graphene honeycomb core material.

Control sample

The difference from example 1 is that: graphene nanoplatelets not added in step (1).

Comparative example 1

The difference from example 1 is that:

(1) adding a small amount of stripped graphene nanosheets into an organic solution containing polymethyl methacrylate and other macromolecules, stirring for 8 hours on a magnetic stirrer at room temperature, putting the magnetic stirrer into an ultrasonic oscillator, and carrying out ultrasonic treatment for 3 hours in a water bath condition of 20 ℃ to obtain a uniform and stable electrostatic spinning solution, wherein the adopted macromolecular material is polyacrylonitrile, the organic solvent is dimethyl sulfoxide, and the electrostatic spinning solution comprises 5 wt% of graphene nanosheets, 1 wt% of polymethyl methacrylate and 25 wt% of macromolecular materials.

Comparative example 2

The difference from example 1 is that:

(3) mixing the graphene fiber film and the thermoplastic material in a mass ratio of 5:100 by a double-screw extruder, and then extruding and granulating to obtain the thermoplastic granules with the graphene sheet layer, wherein the extrusion temperature is set to be 170 ℃.

Comparative example 3

The difference from example 1 is that:

(3) mixing the graphene fiber film and the thermoplastic material in a mass ratio of 25:100 by a double-screw extruder, and then extruding and granulating to obtain the thermoplastic granules with the graphene sheet layer, wherein the extrusion temperature is set to be 170 ℃.

Comparative example 4

The difference from example 1 is that:

(1) the preparation method comprises the steps of melting, blending and extruding the graphene nanosheets, the polymethyl methacrylate and other macromolecules according to the mass ratio of 1:6:25 to obtain granules, wherein the adopted macromolecule material is polyacrylonitrile.

(2) Mixing the granules and the thermoplastic material in a mass ratio of 15:100 by a double-screw extruder, and then extruding and granulating to obtain the thermoplastic granules with the graphene sheet layer, wherein the extrusion temperature is set to be 170 ℃.

(3) And extruding and drying the thermoplastic granules to form a honeycomb stack, and then carrying out electric heating wire cutting treatment to obtain the porous graphene honeycomb core material.

Evaluation of Effect

The density, the mechanical property, the thermal stability, the heat preservation and insulation performance, the sound insulation performance and the like of the porous graphene honeycomb core materials prepared in the reference samples, examples 1 to 3 and comparative examples 1 to 4 are evaluated respectively, wherein the fixtures adopted in the preparation of the porous graphene honeycomb core materials in the examples 1 to 3 and comparative examples 1 to 4 are the same, the structures of the prepared porous graphene honeycomb core materials are the same, and part of the evaluation methods and the evaluation results are shown in table 1:

table 1 evaluation results of porous graphene honeycomb core material

Results and conclusions:

compared with a control sample, the embodiment 1, the embodiment 2 and the embodiment 3 added with a proper amount of graphene obviously improve the mechanical properties such as compression, shearing and the like while realizing the light weight effect, and greatly improve the heat conduction and sound absorption effects. Compared with the comparative example 1, the mass of the graphene is increased, the addition amount of PMMA is reduced, the lightweight effect is general, the mechanical property is improved, the reduction of the heat conductivity coefficient is limited, the improvement of the heat preservation performance is not facilitated, the sound absorption effect is almost unchanged, the pore-forming agent is less, the uniform distribution of the graphene nanosheets is not facilitated, the mass of the graphene is increased, the graphene can be agglomerated into graphite in the preparation process, and the performance of the honeycomb core is influenced. Compared with the comparative example 2 and the comparative example 3, the mechanical property of the core material is slightly improved by adding the graphene, but the preparation ratio of the graphene film to the thermoplastic material is too small, the effect of the graphene is not reflected, the heat preservation and sound absorption performance of the comparative example 2 is almost unchanged, the preparation ratio of the graphene film to the thermoplastic material of the comparative example 3 is too large, the graphene is stacked again and agglomerated into graphite due to too large loading amount, and the heat preservation and sound absorption performance is slightly reduced. Compared with the comparative example 4, except that the density is slightly reduced, the difference of various performances of the fiber membrane and the comparative sample is not large, which shows that the electrostatic spinning process is superior to the melt blending process, because the porous structure and the graphene in the fiber membrane prepared by electrostatic spinning are uniformly distributed, the three-dimensional interlayer structure and the polymer are tightly combined, and the equidirectional distribution of the nano-scale fibers is also beneficial to improving various performances of the core material. Comparing examples 1-3 with comparative examples 1-4, it can be seen that the content and parameters of each substance are within the range of the present invention, and a honeycomb core material with low density and high performance can be obtained, and the content lower or higher than the specified content is not beneficial to improving the comprehensive performance.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.

Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art within the scope of the present invention.