Heat-conducting and insulating cellulose hybrid material based on electrostatic adsorption simulated neural network and preparation method of heat-conducting and insulating cellulose hybrid material

Abstract

The invention discloses a heat-conducting insulating cellulose hybrid material based on an electrostatic adsorption simulated neural network and a preparation method thereof.Based on an electrostatic adsorption mechanism, boron nitride with a high heat conductivity coefficient is adopted as a heat-conducting filler and is loaded on the surfaces of cellulose nanofibers through electrostatic adsorption, and the heat-conducting insulating cellulose hybrid material is prepared; the fiber bundles are mutually lapped to form a heat conduction path similar to a neural network, so that the insulation of the material is ensured, the heat conduction coefficient is relatively high, and the mechanical strength is relatively good; the material has wide application prospects in the fields of heat dissipation of electronic devices, thermal interface materials and the like.

Description

Technical Field

[0001] The invention relates to the technical field of polymer-based functional composite materials, and in particular to a heat-conducting and insulating cellulose composite film based on an electrostatic adsorption neural network and a preparation method thereof. Background Art

[0002] In recent years, with the advancement of science and technology, electronic components and related equipment have gradually tended to be miniaturized, lightweight, integrated, and high-speed, which makes electronic devices generate more heat when in use. If this heat cannot be removed in time, it will affect the accuracy and service life of the equipment. Therefore, it is of great significance to improve the heat dissipation performance of electronic equipment.

[0003] Polymer materials have the advantages of light weight, insulation, and good mechanical properties, and are widely used in the packaging field of electronic devices. Among them, cellulose nanofibers (CNF), as a bio-based polymer material, have good biocompatibility and excellent mechanical properties, which has attracted widespread attention. However, the thermal conductivity of cellulose nanofibers is poor and cannot meet the heat dissipation requirements of electronic devices. Therefore, effectively improving its thermal conductivity has become an important goal.

[0004] The human nervous system is composed of more than 100 billion nerve fibers, which serve as the "track" for signal transmission and have a rapid perception and response to external stimuli. The heat transfer capacity of the material can be greatly enhanced by constructing a heat conduction pathway similar to a neural network. Boron nitride, as an inorganic ceramic filler, has excellent theoretical TC and excellent electrical insulation properties. Boron nitride nanosheets (BNNS) offer great potential in the development of thermally conductive and electrically insulating composite materials. Summary of the invention

[0005] In order to overcome the problem of poor thermal conductivity of traditional cellulose nanofiber materials, the present invention provides a thermally conductive insulating cellulose composite film based on electrostatic adsorption neural network and a preparation method thereof. The thermally conductive insulating cellulose composite film of the present invention has a high in-plane thermal conductivity coefficient, which can quickly dissipate the heat generated by electronic components along the plane of the composite film, while ensuring high thermal conductivity and having excellent insulation performance, and the preparation method is simple to operate and green and environmentally friendly.

[0006] The technical solution of the present invention is as follows:

[0007] A thermally conductive and insulating cellulose composite film based on electrostatic adsorption neural network simulation is prepared according to the following method:

[0008] (1) mixing a ceramic insulating thermal conductive filler, sodium hydroxide and deionized water, performing ball milling and peeling after ultrasonic dispersion, and then centrifuging and drying to obtain a hydroxylated modified thermal conductive filler;

[0009] The ceramic insulating thermal conductive filler is selected from one or more of AlN, BN, SiC, and Al2O3;

[0010] The preferred mass ratio of ceramic insulating thermal conductive filler to sodium hydroxide is 1:10, and the preferred concentration of sodium hydroxide in the mixed system is 2 to 8 mol / L;

[0011] The temperature of ultrasound is controlled at 25-50°C and the time is controlled at 30-120 minutes;

[0012] During ball milling and peeling, the ball mill speed is controlled at 200-500 rpm, and the ball milling time is controlled at 6-10 h;

[0013] During centrifugation, the centrifuge speed is 6000-8000 rpm and the centrifugation time is 20-30 min;

[0014] (2) stirring and mixing the hydroxylated thermally conductive filler and the aqueous solution of the cationic thermosetting resin (10 to 30 minutes), and then adding the mixture to the aqueous dispersion of the cellulose nanofibers and dispersing the mixture by ultrasonication to obtain a thermally conductive filler@cellulose nanofiber mixed dispersion;

[0015] The cationic thermosetting resin is selected from one or more of cationic polyacrylamide (CPAM), polyamide epichlorohydrin (PAE), urea-formaldehyde resin (UF), and melamine formaldehyde resin (MF);

[0016] Based on the total mass of the cellulose nanofibers and the hydroxylated thermally conductive filler, the hydroxylated thermally conductive filler accounts for 10 to 80 wt %;

[0017] The mass ratio of the hydroxylated modified thermal conductive filler to the cationic thermosetting resin is 2 to 6:75;

[0018] The concentration of the aqueous solution of the cationic thermosetting resin is 2 to 8 wt %;

[0019] The concentration of the aqueous dispersion of cellulose nanofibers is 0.1 to 2 wt %;

[0020] During ultrasonic dispersion, the ultrasonic power is controlled at 100-500W, the frequency is controlled at 20-60KHz, and the ultrasonic time is controlled at 30-120min.

[0021] In this step, the negatively charged thermal conductive filler after stripping is mixed with a cationic thermosetting resin, and the positively charged cationic resin molecules are adsorbed on the surface of the thermal conductive filler to convert the overall potential into a positive potential. The positive potential of the mixed system is controlled by adjusting the concentration of the resin, which is a key step of electrostatic adsorption. Subsequently, electrostatic self-assembly is performed with negatively charged cellulose nanofibers (the potential of CNF is negative and has been measured in advance) in water. Under the action of electrostatic adsorption, the thermal conductive filler can be fully coated on the cellulose surface. The dispersion at this time can be expressed as a thermal conductive filler @ cellulose nanofiber mixed dispersion (@ indicates that the thermal conductive filler is adsorbed on the cellulose nanofibers).

[0022] (3) Using a PP membrane as a filter membrane, vacuum filtering the thermal conductive filler@cellulose nanofiber mixed dispersion to obtain a composite membrane material; the obtained composite membrane material is subjected to mechanical molding and drying to obtain the thermal conductive insulating cellulose composite membrane based on electrostatic adsorption neural network simulation;

[0023] During vacuum filtration, the vacuum degree is controlled at -0.06~-0.1MPa;

[0024] The pressure of mechanical molding is 40-50 kPa, and the drying temperature is room temperature;

[0025] In this step, cellulose nanofibers with a one-dimensional structure overlap with each other to form a structure similar to a neural network, and a thermally conductive insulating composite film is prepared by vacuum filtration.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] 1. The preparation method of the present invention is simple, environmentally friendly, and easy to operate;

[0028] 2. The present invention uses a material with a high thermal conductivity coefficient, such as boron nitride, as a thermally conductive filler, adsorbs the insulating thermally conductive filler on the surface of nanocellulose, and then obtains a thermally conductive insulating cellulose film by filtration. The composite film not only ensures thermal conductivity but also insulation;

[0029] 3. The heat-conductive insulating cellulose film prepared by the present invention has anisotropy, and the high in-plane thermal conductivity can make the heat generated by the electronic components dissipate quickly along the plane direction of the composite film. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 : IR spectra of hydroxylated boron nitride after ball milling and pristine boron nitride.

[0031] Figure 2 : Zeta potential of CNF, BNNS-OH and 7.5wt% PAE, and the system potential after BNNS-OH and PAE mixture at different PAE concentrations.

[0032] Figure 3 : Scanning electron microscope image of boron nitride adsorbed on the surface of cellulose nanofibers when the PAE concentration is 7.5wt%.

[0033] Figure 4 : Cross-sectional electron micrograph and elemental analysis spectrum of the composite membrane in Example 1. DETAILED DESCRIPTION

[0034] The present invention is further described below by specific examples, but the protection scope of the present invention is not limited thereto. In the present invention, unless otherwise specified, all equipment and raw materials can be purchased from the market or are commonly used in the industry, and the methods in the following examples, unless otherwise specified, are conventional methods in the art.

[0035] Table 1. Experimental materials

[0036]

[0037] Example 1

[0038] 2g hexagonal boron nitride, 20g sodium hydroxide, and 100ml deionized water were mixed in a beaker and sealed with a sealing film. Then, the mixture was placed in an ultrasonic instrument for ultrasonic dispersion at room temperature for 10 minutes, and then transferred into a ball mill. The mixture was ball milled at 400rpm for 8 hours. After the ball milling, the ball milling liquid was taken out and then centrifuged at 8000r / min for 25 minutes. After the centrifugation, the mixture was dried in an oven at 80℃ for 4 hours to obtain the thermal conductive filler BNNS-OH.

[0039] 0.02 g BNNS-OH was mixed with 10 mL of 7.5 wt% PAE aqueous solution under magnetic stirring for 25 min, and then added to 8 mL of 1.0 wt% cellulose nanofiber aqueous dispersion (the mass ratio of cellulose nanofiber to thermal conductive filler BNNS-OH was 80 / 20), and ultrasonic dispersion was performed at an ultrasonic frequency of 40 KHz and an ultrasonic time of 30 min to obtain a BNNS-OH@CNF mixed dispersion.

[0040] The BNNS-OH@CNF mixed dispersion was vacuum filtered to prepare a thermally conductive insulating composite film; PP membrane was used as the filter membrane and the vacuum degree was controlled at -0.09MPa;

[0041] The composite film was molded at 45 kPa for 24 hours and dried at room temperature to obtain an anisotropic thermally conductive insulating cellulose composite film; the thickness of the thermally conductive insulating layer on the PP layer was 100 μm.

[0042] Example 2

[0043] 2g hexagonal boron nitride, 20g sodium hydroxide, and 100ml deionized water were mixed in a beaker and sealed with a sealing film. Then, the mixture was placed in an ultrasonic instrument for ultrasonic dispersion at room temperature for 10 minutes, and then transferred into a ball mill. The mixture was ball milled at 400rpm for 8 hours. After the ball milling, the ball milling liquid was taken out and then centrifuged at 8000r / min for 25 minutes. After the centrifugation, the mixture was dried in an oven at 80℃ for 4 hours to obtain the thermal conductive filler BNNS-OH.

[0044] 0.03 g BNNS-OH was mixed with 10 mL of 7.5 wt% PAE aqueous solution under magnetic stirring for 25 min, and then added to 7 mL of 1.0 wt% cellulose nanofiber aqueous dispersion (the mass ratio of cellulose nanofiber to thermal conductive filler BNNS-OH was 70 / 30), and ultrasonic dispersion was performed at an ultrasonic frequency of 40 kHz and an ultrasonic time of 30 min to obtain a BNNS-OH@CNF mixed dispersion.

[0045] The BNNS-OH@CNF mixed dispersion was vacuum filtered to prepare a thermally conductive insulating composite film; PP membrane was used as the filter membrane and the vacuum degree was controlled at -0.09MPa;

[0046] The composite film was molded at 45 kPa for 24 hours and dried at room temperature to obtain an anisotropic thermally conductive insulating cellulose composite film; the thickness of the thermally conductive insulating layer on the PP layer was 100 μm.

[0047] Example 3

[0048] 2g hexagonal boron nitride, 20g sodium hydroxide, and 100ml deionized water were mixed in a beaker and sealed with a sealing film. Then, the mixture was placed in an ultrasonic instrument for ultrasonic dispersion at room temperature for 10 minutes, and then transferred into a ball mill. The mixture was ball milled at 400rpm for 8 hours. After the ball milling, the ball milling liquid was taken out and then centrifuged at 8000r / min for 25 minutes. After the centrifugation, the mixture was dried in an oven at 80℃ for 4 hours to obtain the thermal conductive filler BNNS-OH.

[0049] 0.04 g BNNS-OH was mixed with 10 mL of 7.5 wt% PAE aqueous solution under magnetic stirring for 25 min, and then added to 6 mL of 1.0 wt% cellulose nanofiber aqueous dispersion (the mass ratio of cellulose nanofiber to thermal conductive filler BNNS-OH was 60 / 40), and ultrasonic dispersion was performed at an ultrasonic frequency of 40 kHz and an ultrasonic time of 30 min to obtain a BNNS-OH@CNF mixed dispersion.

[0050] The BNNS-OH@CNF mixed dispersion was vacuum filtered to prepare a thermally conductive insulating composite film; PP membrane was used as the filter membrane and the vacuum degree was controlled at -0.09MPa;

[0051] The composite film was molded at 45 kPa for 24 hours and dried at room temperature to obtain an anisotropic thermally conductive insulating cellulose composite film; the thickness of the thermally conductive insulating layer on the PP layer was 100 μm.

[0052] Example 4

[0053] 2g hexagonal boron nitride, 20g sodium hydroxide, and 100ml deionized water were mixed in a beaker and sealed with a sealing film. Then, the mixture was placed in an ultrasonic instrument for ultrasonic dispersion at room temperature for 10 minutes, and then transferred into a ball mill. The mixture was ball milled at 400rpm for 8 hours. After the ball milling, the ball milling liquid was taken out and then centrifuged at 8000r / min for 25 minutes. After the centrifugation, the mixture was dried in an oven at 80℃ for 4 hours to obtain the thermal conductive filler BNNS-OH.

[0054] 0.05 g BNNS-OH was mixed with 10 mL of 7.5 wt% PAE aqueous solution under magnetic stirring for 25 min, and then added into 5 mL of 1.0 wt% cellulose nanofiber aqueous dispersion (the mass ratio of cellulose nanofiber to thermal conductive filler BNNS-OH was 50 / 50), and ultrasonic dispersion was performed at an ultrasonic frequency of 40 KHz and an ultrasonic time of 30 min to obtain a BNNS-OH@CNF mixed dispersion.

[0055] The BNNS-OH@CNF mixed dispersion was vacuum filtered to prepare a thermally conductive insulating composite film; PP membrane was used as the filter membrane and the vacuum degree was controlled at -0.09MPa;

[0056] The composite film was molded at 45 kPa for 24 hours and dried at room temperature to obtain an anisotropic thermally conductive insulating cellulose composite film; the thickness of the thermally conductive insulating layer on the PP layer was 100 μm.

[0057] Example 5

[0058] 2g hexagonal boron nitride, 20g sodium hydroxide, and 100ml deionized water were mixed in a beaker and sealed with a sealing film. Then, the mixture was placed in an ultrasonic instrument for ultrasonic dispersion at room temperature for 10 minutes, and then transferred into a ball mill. The mixture was ball milled at 400rpm for 8 hours. After the ball milling, the ball milling liquid was taken out and then centrifuged at 8000r / min for 25 minutes. After the centrifugation, the mixture was dried in an oven at 80℃ for 4 hours to obtain the thermal conductive filler BNNS-OH.

[0059] 0.06 g BNNS-OH was mixed with 10 mL of 7.5 wt% PAE aqueous solution under magnetic stirring for 25 min, and then added to 4 mL of 1.0 wt% cellulose nanofiber aqueous dispersion (the mass ratio of cellulose nanofiber to thermal conductive filler BNNS-OH was 40 / 60), and ultrasonic dispersion was performed at a frequency of 40 kHz and a time of 30 min to obtain a BNNS-OH@CNF mixed dispersion.

[0060] The BNNS-OH@CNF mixed dispersion was vacuum filtered to prepare a thermally conductive insulating composite film; PP membrane was used as the filter membrane and the vacuum degree was controlled at -0.09MPa;

[0061] The composite film was molded at 45 kPa for 24 hours and dried at room temperature to obtain an anisotropic thermally conductive insulating cellulose composite film; the thickness of the thermally conductive insulating layer on the PP layer was 100 μm.

[0062] Comparative Example 1 (pure cellulose film)

[0063] 10 mL of 1.0 wt% cellulose nanofiber aqueous dispersion was ultrasonically dispersed at an ultrasonic frequency of 40 KHz and an ultrasonic time of 30 min to obtain a pure CNF aqueous dispersion.

[0064] The cellulose nanofiber dispersion was vacuum filtered to prepare a thermally conductive insulating composite film; a PP membrane was used as the filter membrane and the vacuum degree was controlled at -0.09 MPa;

[0065] The film was molded at 45 kPa for 24 hours and dried at room temperature to obtain an anisotropic thermally conductive insulating cellulose film; the thickness of the thermally conductive insulating layer on the PP layer was 100 μm.

[0066] Comparative Example 2 (Direct blending of boron nitride and cellulose nanofibers)

[0067] 4 mL of 1.0 wt% cellulose nanofiber aqueous dispersion was mixed with 0.06 g of hexagonal boron nitride (the mass ratio of cellulose nanofiber to thermal conductive filler hexagonal boron nitride was 40 / 60), and ultrasonic dispersion was performed at an ultrasonic frequency of 40 KHz and an ultrasonic time of 30 min to obtain a BN / CNF mixed dispersion ( / represents direct blending without adsorption effect).

[0068] The BN / CNF mixed dispersion was vacuum filtered to prepare a thermally conductive insulating composite film; a PP membrane was used as the filter membrane and the vacuum degree was controlled at -0.09 MPa;

[0069] The composite film was molded at 45 kPa for 24 hours and dried at room temperature to obtain an anisotropic thermally conductive insulating cellulose composite film; the thickness of the thermally conductive insulating layer on the PP layer was 100 μm.

[0070] Comparative Example 3 (Ball-milling of boron nitride and blending with cellulose nanofibers)

[0071] Mix 2g of hexagonal boron nitride and 100ml of deionized water in a beaker, seal the beaker with a sealing film, and then place it in an ultrasonic instrument for ultrasonic dispersion at room temperature for 10 minutes, and then transfer it to a ball mill. Ball mill at a speed of 400rpm for 8h, take out the ball milling liquid after ball milling, and then centrifuge it at a speed of 8000r / min for 25min. After centrifugation, dry it in an oven at 80℃ for 4h to obtain the thermal conductive filler BNNS;

[0072] 4 mL of 1.0 wt% cellulose nanofiber aqueous dispersion was mixed with 0.06 g of BNNS (the mass ratio of cellulose nanofiber to thermal conductive filler BNNS was 40 / 60), and ultrasonic dispersion was performed at an ultrasonic frequency of 40 KHz and an ultrasonic time of 30 min to obtain a BNNS / CNF mixed dispersion.

[0073] The BNNS / CNF mixed dispersion was vacuum filtered to prepare a thermally conductive insulating composite film; a PP membrane was used as the filter membrane and the vacuum degree was controlled at -0.09 MPa;

[0074] The composite film was molded at 45 kPa for 24 hours and dried at room temperature to obtain an anisotropic thermally conductive insulating cellulose composite film; the thickness of the thermally conductive insulating layer on the PP layer was 100 μm.

[0075] Comparative Example 4 (Ball-milling and hydroxylation of boron nitride followed by blending with cellulose nanofibers)

[0076] 2g hexagonal boron nitride, 20g sodium hydroxide, and 100ml deionized water were mixed in a beaker and sealed with a sealing film. Then, the mixture was placed in an ultrasonic instrument for ultrasonic dispersion at room temperature for 10 minutes, and then transferred into a ball mill. The mixture was ball milled at 400rpm for 8 hours. After the ball milling, the ball milling liquid was taken out and then centrifuged at 8000r / min for 25 minutes. After the centrifugation, the mixture was dried in an oven at 80℃ for 4 hours to obtain the thermal conductive filler BNNS-OH.

[0077] 4 mL of 1.0 wt% cellulose nanofiber aqueous dispersion was mixed with 0.06 g of BNNS-OH (the mass ratio of cellulose nanofiber to thermal conductive filler BNNS-OH was 40 / 60), and ultrasonic dispersion was performed at an ultrasonic frequency of 40 KHz and an ultrasonic time of 30 min to obtain a BNNS-OH / CNF dispersion.

[0078] The BNNS-OH / CNF dispersion was vacuum filtered to prepare a thermally conductive insulating composite film; a PP membrane was used as the filter membrane and the vacuum degree was controlled at -0.09 MPa;

[0079] The composite film was molded at 45 kPa for 24 hours and dried at room temperature to obtain an anisotropic thermally conductive insulating cellulose composite film; the thickness of the thermally conductive insulating layer on the PP layer was 100 μm.

[0080] Comparative Example 5 (mixing boron nitride with PAE and then with cellulose nanofibers)

[0081] 0.06 g of thermal conductive filler BN was mixed with 10 mL of 7.5 wt% PAE aqueous solution under magnetic stirring for 25 min, and then added into 4 mL of 1.0 wt% cellulose nanofiber aqueous dispersion (cellulose nanofiber to thermal conductive filler BN mass ratio 40 / 60), and ultrasonically dispersed at an ultrasonic frequency of 40 KHz and an ultrasonic time of 30 min to obtain a BN@CNF dispersion;

[0082] The BN@CNF dispersion was vacuum filtered to prepare a thermally conductive insulating composite film; a PP membrane was used as the filter membrane and the vacuum degree was controlled at -0.09 MPa;

[0083] The composite film was molded at 45 kPa for 24 hours and dried at room temperature to obtain an anisotropic thermally conductive insulating cellulose composite film; the thickness of the thermally conductive insulating layer on the PP layer was 100 μm.

[0084] The performance tests were conducted on the composite membrane samples of Examples 1 to 5 and Comparative Examples 1 to 4. The test results are shown in Table 2:

[0085] Table 2. Measurement results of composite films of Examples 1 to 5 and Comparative Examples 1 to 4

[0086]

[0087]

[0088] As can be seen from Table 2, the thermal conductivity of pure cellulose film is poor. After adding thermal conductive fillers, the thermal conductivity coefficient is improved, and the resistivity is still high, which can maintain the original electrical insulation performance. Although the thermal conductivity of the composite membrane obtained by simple blending and filtration with boron nitride is improved, the mechanical properties are greatly reduced. After ball milling, the mechanical properties are improved compared with direct blending. The performance of hydroxylation treatment during ball milling is not much different from that of ball milling alone. In addition, the thermal conductivity of the thermally conductive insulating composite film prepared in Examples 1 to 5 increases with the increase in the proportion of thermal conductive fillers. Due to the anisotropy, the heat accumulated by the electronic components will dissipate along the plane direction, extending the service life of the electronic components. The thermal conductive filler is adsorbed on the surface of the cellulose nanofibers by electrostatic attraction, and then a dense composite membrane is formed by vacuum filtration, which helps to form a thermal conductive path, but the addition of thermal conductive fillers should also be moderate. On the one hand, excessive filler load will affect film formation, and on the other hand, the mechanical properties will be seriously affected and lose their use value.

Claims

1. A thermally conductive and insulating cellulose composite film based on electrostatic adsorption neural network, characterized in that: Prepared as follows: (1) mixing a ceramic insulating thermal conductive filler, sodium hydroxide and deionized water, performing ball milling and peeling after ultrasonic dispersion, and then centrifuging and drying to obtain a hydroxylated modified thermal conductive filler; (2) mixing the hydroxylated thermally conductive filler with an aqueous solution of a cationic thermosetting resin, and then adding the mixture to an aqueous dispersion of cellulose nanofibers, and dispersing the mixture by ultrasonication to obtain a thermally conductive filler@cellulose nanofiber mixed dispersion; (3) Using PP membrane as filter membrane, the thermal conductive filler @ cellulose nanofiber mixed dispersion is vacuum filtered to obtain a composite membrane material; the obtained composite membrane material is subjected to mechanical molding and drying to obtain the thermal conductive insulating cellulose composite membrane based on electrostatic adsorption neural network.

2. The thermally conductive insulating cellulose composite film based on electrostatic adsorption neural network according to claim 1, characterized in that: In step (1), the ceramic insulating thermal conductive filler is selected from one or more of AlN, BN, SiC, and Al2O3.

3. The thermally conductive insulating cellulose composite film based on electrostatic adsorption neural network as claimed in claim 1, characterized in that: In step (1), the mass ratio of the ceramic insulating thermal conductive filler to the sodium hydroxide is 1:10, and the concentration of the sodium hydroxide in the mixed system is 2 to 8 mol / L.

4. The thermally conductive insulating cellulose composite film based on electrostatic adsorption neural network according to claim 1, characterized in that: In step (1), during ball milling and peeling, the ball mill speed is controlled at 200 to 500 rpm, and the ball milling time is controlled at 6 to 10 hours.

5. The thermally conductive insulating cellulose composite film based on electrostatic adsorption neural network as claimed in claim 1, characterized in that: In step (2), the cationic thermosetting resin is selected from one or more of cationic polyacrylamide, polyamide epichlorohydrin, urea-formaldehyde resin, and melamine-formaldehyde resin.

6. The thermally conductive insulating cellulose composite film based on electrostatic adsorption neural network according to claim 1, characterized in that: In step (2), based on the total mass of the cellulose nanofibers and the hydroxylated thermally conductive filler, the hydroxylated thermally conductive filler accounts for 10 to 80 wt %.

7. The thermally conductive insulating cellulose composite film based on electrostatic adsorption neural network according to claim 1, characterized in that: In step (2), the mass ratio of the hydroxylated modified thermal conductive filler to the cationic thermosetting resin is 2 to 6:

75.

8. The thermally conductive insulating cellulose composite film based on electrostatic adsorption neural network according to claim 1, characterized in that: In step (2), the concentration of the aqueous solution of the cationic thermosetting resin is 2 to 8 wt %.

9. The thermally conductive insulating cellulose composite film based on electrostatic adsorption neural network according to claim 1, characterized in that: In step (2), the concentration of the aqueous dispersion of cellulose nanofibers is 0.1-2 wt %.

Images