Preparation method of wolf tooth rod-shaped graphene loaded boron nitride whisker and application thereof in heat-conducting TPV material

Abstract

The application discloses a preparation method of wolf-tooth-shaped graphene loaded boron nitride whiskers and application of the wolf-tooth-shaped graphene loaded boron nitride whiskers in a heat-conducting TPV material. The heat-conducting material has a special wolf-tooth-shaped structure, can easily form complete heat-conducting channels in different orientations of a resin material, has the advantages of a small addition amount, good heat-conducting performance and the like. Compared with traditional heat-conducting TPV materials, the heat-conducting TPV material prepared by the application has more balanced mechanical performance and better processing performance. The raw materials are widely sourced, non-toxic, the processing method is simple, the cost is low, and the heat-conducting TPV material has a wide market prospect.

Description

Technical Field

[0001] This invention belongs to the field of inorganic materials technology, specifically relating to a method for preparing wolf-tooth-shaped graphene-supported boron nitride whiskers and their application in thermally conductive TPV materials. Background Technology

[0002] Thermoplastic dynamic vulcanizate (TPV) is a type of elastomer that combines the easy processing properties of thermoplastics with the high elasticity and stretchability of rubber. It has important application prospects in the electronics, electrical appliances, and automotive industries and has become a hot research topic in recent years.

[0003] The traditional method to improve the thermal conductivity of TPV is to add thermally conductive inorganic fillers to the matrix. However, since the filler content is usually higher than 50%, the mechanical properties and processing properties of the material drop sharply. In order to reduce the amount of filler, the use of functional nanofillers is usually the best modification method for thermally conductive composite materials. Summary of the Invention

[0004] The purpose of this invention is to provide a method for preparing wolf-tooth-shaped graphene-supported boron nitride whiskers and their application in thermally conductive TPV materials. The graphene-supported boron nitride whiskers prepared by this method exhibit a unique wolf-tooth shape, effectively establishing thermally conductive channels. They offer advantages such as low addition amount, excellent thermal conductivity, and minimal damage to the overall mechanical properties of the material.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A method for preparing wolf-tooth-shaped graphene-supported boron nitride whiskers includes the following steps: (1) Preparation of rolled rod-shaped graphene oxide Graphene oxide was prepared using the Hummers method. The prepared graphene oxide was added to deionized water to prepare a graphene oxide dispersion of a certain concentration. After ultrasonic dispersion, centrifugation and drying, and filtration, it was added to deionized water to form a graphene oxide dispersion. The graphene oxide dispersion was then dropped into liquid nitrogen using a pipette and then freeze-dried under vacuum to obtain rolled rod-shaped graphene oxide. (2) Surface treatment of boron nitride whiskers Boron nitride whiskers were mixed with an organic solvent to prepare a boron nitride whisker solution. A coupling agent was added, and the reaction was carried out at a certain temperature to obtain surface-treated boron nitride whiskers. (3) Preparation of wolf-tooth rod-shaped graphene supported boron nitride whiskers A certain mass of the coiled rod-shaped graphene oxide obtained in step (1) is weighed and added to the organic solvent of the coupling agent. After reflux reaction under nitrogen atmosphere, the surface-treated boron nitride whiskers obtained in step (2) are added. After the reaction continues at a certain temperature, the mixture is filtered, dried and baked to obtain the wolf-tooth rod-shaped graphene-supported boron nitride whiskers.

[0006] Further, in step (1), the concentration of the graphene oxide dispersion is 1~8 mg / mL, the ultrasonic dispersion is 1~5 h, the centrifugation speed is 3000~8000 r / min, the centrifugation time is 5~20 min, the vacuum freeze-drying time is 72~140 h, and the size of the obtained coiled rod-shaped graphene oxide is 300~500 nm with an aspect ratio of 30~50:1.

[0007] Further, in step (2), the organic solvent is at least one of methanol, ethanol, and acetone; the coupling agent is at least one of aluminate coupling agent, titanate coupling agent, and silane coupling agent; the boron nitride solution contains boron nitride whiskers: organic solvent 1~5g: 300~600mL; the boron nitride whisker size is 50~200nm, and the aspect ratio is 50~100:1; the reaction temperature is 20~80℃, and the reaction time is 30~120min.

[0008] Further, the organic solvent in step (3) is at least one of methanol, ethanol, and acetone; the coupling agent is at least one of aluminate coupling agent, titanate coupling agent, and silane coupling agent; the ratio of the coiled rod-shaped graphene oxide: coupling agent: organic solvent: surface-treated boron nitride whiskers is 1~5g:0.05~0.15g:300~600mL:3~10g; the obtained wolf-tooth rod-shaped graphene-supported boron nitride whiskers have a special wolf-tooth rod-shaped structure with a size of 0.5~2μm and an aspect ratio of 10~20:1.

[0009] Furthermore, a type of rod-shaped graphene-supported boron nitride whisker is applied to a thermally conductive TPV material. The characteristic feature is that the mass ratio of the rod-shaped graphene-supported boron nitride whisker to TPV and other processing aids (compatibilizer, lubricant, antioxidant) is 10~20:60~80:10~20, and the thermally conductive TPV material is obtained by melt extrusion granulation at 180~220℃.

[0010] Furthermore, the thermally conductive TPV material obtained has a thermal conductivity ≥1.5W / m·k.

[0011] The present invention has the following beneficial effects: (1) Prepare a wolf-tooth-shaped graphene-supported boron nitride whisker. This thermally conductive material has a special wolf-tooth-shaped structure, which can easily form complete thermally conductive channels in different orientations of the resin material. It has the advantages of low addition amount and good thermal conductivity.

[0012] (2) The prepared wolf-tooth-shaped graphene loaded with boron nitride whiskers is applied to the thermally conductive TPV material. Compared with the traditional thermally conductive TPV material, the thermally conductive TPV material prepared by this invention has more balanced mechanical properties and better processing performance.

[0013] (3) The raw materials are widely available, non-toxic, and the processing method is simple and low-cost, with broad market prospects. Attached Figure Description

[0014] Figure 1 This is a SEM image of the wolf-tooth-shaped graphene loaded with boron nitride whiskers prepared in Example 1 of the present invention.

[0015] Figure 2 SEM images of cross-sections of graphene-supported boron nitride whiskers in a wolf-tooth-shaped graphene structure applied to a thermally conductive TPV material. Detailed Implementation

[0016] The present invention will be described in more detail below through specific embodiments, but the scope of protection of the present invention is not limited to these embodiments. Example 1

[0017] A method for preparing wolf-tooth-shaped graphene-supported boron nitride whiskers includes the following steps: (1) Preparation of rolled rod-shaped graphene oxide Graphene oxide was prepared using the Hummers method. The prepared graphene oxide was added to deionized water to prepare a graphene oxide dispersion with a concentration of 2 mg / mL. After ultrasonic dispersion for 1 h, the dispersion was centrifuged at 3000 r / min for 5 min. After filtration, the dispersion was added to deionized water to form a graphene oxide dispersion. The graphene oxide dispersion was then pipetted into liquid nitrogen and freeze-dried under vacuum for 72 h to obtain coiled rod-shaped graphene oxide. The size of the obtained coiled rod-shaped graphene oxide was measured to be 300-400 nm with an aspect ratio of 30-40:1. (2) Surface treatment of boron nitride whiskers A boron nitride whisker solution was prepared by mixing 2g of boron nitride whiskers with 300mL of ethanol. An aluminate coupling agent was then added, and the solution was reacted at 20℃ for 60min to obtain surface-treated boron nitride whiskers. Testing showed that the size of the surface-treated boron nitride whiskers was 50~100nm, with an aspect ratio of 50~80:1. (3) Preparation of wolf-tooth rod-shaped graphene supported boron nitride whiskers 3g of the coiled rod-shaped graphene oxide obtained in step (1) was weighed and added to 300mL of methanol containing 0.05g of silane coupling agent. After reflux reaction under nitrogen atmosphere, 3g of surface-treated boron nitride whiskers obtained in step (2) were added. After continuing the reaction at a certain temperature, the mixture was filtered, dried, and then baked to obtain wolf-tooth rod-shaped graphene-supported boron nitride whiskers. The obtained wolf-tooth rod-shaped graphene-supported boron nitride whiskers exhibited a special wolf-tooth rod-shaped structure. The SEM image is shown below. Figure 1As shown, the dimensions are 0.5~1.5μm, and the aspect ratio is 10~15:1.

[0018] The aforementioned spike-shaped graphene-supported boron nitride whiskers were applied to a thermally conductive TPV material. The mass ratio of the spike-shaped graphene-supported boron nitride whiskers to TPV and other processing aids (compatibilizer, lubricant, antioxidant) was 20:60:20. The thermally conductive TPV material was obtained by melt extrusion granulation at 180~220℃. The thermal conductivity of the obtained thermally conductive TPV material was tested to be 2.35 W / m·K. SEM images are shown below. Figure 2 As shown. Example 2

[0019] (1) Preparation of rolled rod-shaped graphene oxide Graphene oxide was prepared using the Hummers method. The prepared graphene oxide was added to deionized water to prepare a graphene oxide dispersion with a concentration of 4 mg / mL. After ultrasonic dispersion for 2 h, the dispersion was centrifuged at 4000 r / min for 10 min. After filtration, the dispersion was added to deionized water to form a graphene oxide dispersion. The graphene oxide dispersion was then dropped into liquid nitrogen using a pipette and freeze-dried under vacuum for 90 h to obtain coiled rod-shaped graphene oxide. The size of the obtained coiled rod-shaped graphene oxide was measured to be 400~500 nm with an aspect ratio of 40~50:1. (2) Surface treatment of boron nitride whiskers A boron nitride whisker solution was prepared by mixing 3g of boron nitride whiskers with 350mL of methanol. A silane coupling agent was then added, and the solution was reacted at 30℃ for 45min to obtain surface-treated boron nitride whiskers. The surface-treated boron nitride whiskers were tested to have a size of 100~150nm and an aspect ratio of 80~100:1. (3) Preparation of wolf-tooth rod-shaped graphene supported boron nitride whiskers 4g of the coiled rod-shaped graphene oxide obtained in step (1) was weighed and added to 400mL of ethanol containing 0.1g of silane coupling agent. After reflux reaction under nitrogen atmosphere, 5g of surface-treated boron nitride whiskers obtained in step (2) were added. The reaction was continued at a certain temperature, and then filtered, dried, and baked to obtain wolf-tooth rod-shaped graphene-supported boron nitride whiskers. The obtained wolf-tooth rod-shaped graphene-supported boron nitride whiskers exhibited a special wolf-tooth rod-shaped structure with a size of 1~2μm and an aspect ratio of 15~20:1.

[0020] The aforementioned wolf-tooth-shaped graphene-supported boron nitride whiskers were applied to a thermally conductive TPV material. The mass ratio of the wolf-tooth-shaped graphene-supported boron nitride whiskers to TPV and other processing aids (compatibilizer, lubricant, antioxidant) was 15:70:15. The thermally conductive TPV material was obtained by melt extrusion granulation at 180~220℃. The thermal conductivity of the obtained thermally conductive TPV material was tested to be 2.03 W / m·K. Example 3

[0021] (1) Preparation of rolled rod-shaped graphene oxide Graphene oxide was prepared using the Hummers method. The prepared graphene oxide was added to deionized water to prepare a graphene oxide dispersion with a concentration of 6 mg / mL. After ultrasonic dispersion for 3 h, the dispersion was centrifuged at 5000 r / min for 15 min. After filtration, the dispersion was added to deionized water to form a graphene oxide dispersion. The graphene oxide dispersion was then pipetted into liquid nitrogen and freeze-dried under vacuum for 100 h to obtain coiled rod-shaped graphene oxide. The size of the obtained coiled rod-shaped graphene oxide was measured to be 350~400 nm with an aspect ratio of 45~50:1. (2) Surface treatment of boron nitride whiskers A boron nitride whisker solution was prepared by mixing 4g of boron nitride whiskers with 500mL of acetone. A titanate coupling agent was then added, and the solution was reacted at 40℃ for 45min to obtain surface-treated boron nitride whiskers. Testing showed that the size of the surface-treated boron nitride whiskers was 150~200nm, with an aspect ratio of 60~100:1. (3) Preparation of wolf-tooth rod-shaped graphene supported boron nitride whiskers 4.5g of the coiled rod-shaped graphene oxide obtained in step (1) was weighed and added to 500mL of acetone containing 0.15g of silane coupling agent. After reflux reaction under nitrogen atmosphere, 5g of surface-treated boron nitride whiskers obtained in step (2) were added. The reaction was continued at a certain temperature, and then filtered, dried, and baked to obtain wolf-tooth rod-shaped graphene-supported boron nitride whiskers. The obtained wolf-tooth rod-shaped graphene-supported boron nitride whiskers exhibited a special wolf-tooth rod-shaped structure with a size of 1~1.5μm and an aspect ratio of 10~15:1.

[0022] The aforementioned wolf-tooth-shaped graphene-supported boron nitride whiskers were applied to a thermally conductive TPV material. The mass ratio of the wolf-tooth-shaped graphene-supported boron nitride whiskers to TPV and other processing aids (compatibilizer, lubricant, antioxidant) was 20:65:15. The thermally conductive TPV material was obtained by melt extrusion granulation at 180~220℃. The thermal conductivity of the obtained thermally conductive TPV material was tested to be 2.27 W / m·K. Example 4

[0023] (1) Preparation of rolled rod-shaped graphene oxide Graphene oxide was prepared using the Hummers method. The prepared graphene oxide was added to deionized water to prepare a graphene oxide dispersion with a concentration of 6 mg / mL. After ultrasonic dispersion for 5 h, the dispersion was centrifuged at 6000 r / min for 20 min. After filtration, the dispersion was added to deionized water to form a graphene oxide dispersion. The graphene oxide dispersion was then dropped into liquid nitrogen using a pipette and freeze-dried under vacuum for 72 h to obtain coiled rod-shaped graphene oxide. The size of the obtained coiled rod-shaped graphene oxide was measured to be 450~500 nm with an aspect ratio of 35~50:1. (2) Surface treatment of boron nitride whiskers A boron nitride whisker solution was prepared by mixing 5 g of boron nitride whiskers with 600 mL of ethanol. An aluminate coupling agent was then added, and the solution was reacted at 60 °C for 120 min to obtain surface-treated boron nitride whiskers. The surface-treated boron nitride whiskers were tested to have a size of 150–200 nm and an aspect ratio of 50–75:1. (3) Preparation of wolf-tooth rod-shaped graphene supported boron nitride whiskers 5g of the coiled rod-shaped graphene oxide obtained in step (1) was weighed and added to 600mL of ethanol containing 0.15g of silane coupling agent. After reflux reaction under nitrogen atmosphere, 8g of surface-treated boron nitride whiskers obtained in step (2) were added. The reaction was continued at a certain temperature, and then filtered, dried, and baked to obtain wolf-tooth rod-shaped graphene-supported boron nitride whiskers. The obtained wolf-tooth rod-shaped graphene-supported boron nitride whiskers exhibited a special wolf-tooth rod-shaped structure with a size of 1.5~2μm and an aspect ratio of 16~20:1.

[0024] The above-prepared wolf-tooth-shaped graphene-supported boron nitride whiskers were applied to a thermally conductive TPV material. The mass ratio of the wolf-tooth-shaped graphene-supported boron nitride whiskers to TPV and other processing aids (compatibilizer, lubricant, antioxidant) was 20:70:10. The thermally conductive TPV material was obtained by melt extrusion granulation at 180~220℃. The thermal conductivity of the obtained thermally conductive TPV material was tested to be 1.94 W / m·K.

[0025] Comparative Example 1 A method for preparing coiled rod-shaped graphene oxide includes the following steps: (1) Preparation of rolled rod-shaped graphene oxide Graphene oxide was prepared using the Hummers method. The prepared graphene oxide was added to deionized water to prepare a graphene oxide dispersion with a concentration of 2 mg / mL. After ultrasonic dispersion for 1 h, the dispersion was centrifuged at 3000 r / min for 5 min. After filtration, the dispersion was added to deionized water to form a graphene oxide dispersion. The graphene oxide dispersion was then pipetted into liquid nitrogen and freeze-dried under vacuum for 72 h to obtain coiled rod-shaped graphene oxide. The size of the obtained coiled rod-shaped graphene oxide was measured to be 300-400 nm with an aspect ratio of 30-40:1.

[0026] The coiled rod-shaped graphene oxide prepared above was applied to the thermally conductive TPV material. The mass ratio of coiled rod-shaped graphene oxide to TPV and other processing aids (compatibilizer, lubricant, antioxidant) was 20:60:20. The thermally conductive TPV material was obtained by melt extrusion granulation at 180~220℃. The thermal conductivity of the obtained thermally conductive TPV material was tested to be 1.53W / m·k.

[0027] The difference between Comparative Example 1 and Example 1 is that Example 1 uses a wolf-tooth-shaped graphene loaded with boron nitride whiskers as a thermally conductive material to prepare a thermally conductive TPV material, while Comparative Example 1 only uses rolled-up rod-shaped graphene oxide as a thermally conductive material to prepare a thermally conductive TPV material.

[0028] Comparative Example 2 (1) Preparation of rolled rod-shaped graphene oxide Graphene oxide was prepared using the Hummers method. The prepared graphene oxide was added to deionized water to prepare a graphene oxide dispersion with a concentration of 2 mg / mL. After ultrasonic dispersion for 1 h, the dispersion was centrifuged at 3000 r / min for 5 min. After filtration, the dispersion was added to deionized water to form a graphene oxide dispersion. The graphene oxide dispersion was then pipetted into liquid nitrogen and freeze-dried under vacuum for 72 h to obtain coiled rod-shaped graphene oxide. The size of the obtained coiled rod-shaped graphene oxide was measured to be 300-400 nm with an aspect ratio of 30-40:1. (2) Surface treatment of boron nitride whiskers A boron nitride whisker solution was prepared by mixing 2 g of boron nitride whiskers with 300 mL of ethanol. An aluminate coupling agent was then added, and the solution was reacted at 20 °C for 60 min to obtain surface-treated boron nitride whiskers. Testing showed that the surface-treated boron nitride whiskers had a size of 50–100 nm and an aspect ratio of 50–80:1.

[0029] The above-prepared curled rod-shaped graphene oxide and surface-treated boron nitride whiskers were applied to thermally conductive TPV materials. The mass ratio of the curled rod-shaped graphene oxide and surface-treated boron nitride whiskers to TPV and other processing aids (compatibilizer, lubricant, antioxidant) was 10:10:60:20. The thermally conductive TPV materials were obtained by melt extrusion granulation at 180~220℃. The thermal conductivity of the obtained thermally conductive TPV materials was tested to be 1.73 W / m·K.

[0030] The difference between Comparative Example 2 and Example 1 is that Comparative Example 2 lacks step (3) of loading boron nitride whiskers onto wolf-tooth-shaped graphene, and adopts a direct addition method.

[0031] The specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various modifications or variations within the scope of the claims, which do not affect the essence of the present invention.

Claims

1. A method for preparing wolf-tooth-shaped graphene-supported boron nitride whiskers, characterized in that, Includes the following steps: (1) Preparation of coiled rod-shaped graphene oxide Graphene oxide was prepared using the Hummers method. The prepared graphene oxide was added to deionized water to prepare a graphene oxide dispersion of a certain concentration. After ultrasonic dispersion, centrifugation and drying, and filtration, it was added to deionized water to form a graphene oxide dispersion. The graphene oxide dispersion was then dropped into liquid nitrogen using a pipette and then freeze-dried under vacuum to obtain rolled rod-shaped graphene oxide. (2) Surface treatment of boron nitride whiskers Boron nitride whiskers were mixed with an organic solvent to prepare a boron nitride whisker solution. A coupling agent was added, and the reaction was carried out at a certain temperature to obtain surface-treated boron nitride whiskers. (3) Preparation of wolf-tooth rod-shaped graphene supported boron nitride whiskers Weigh a certain mass of the curled rod-shaped graphene oxide obtained in step (1) and add it to the organic solvent of the coupling agent. After reflux reaction under nitrogen atmosphere, add the surface-treated boron nitride whiskers obtained in step (2). After continuing the reaction at a certain temperature, filter, dry and bake to obtain the wolf-tooth rod-shaped graphene supported boron nitride whiskers. The concentration of the graphene oxide dispersion in step (1) is 1~8 mg / mL, the ultrasonic dispersion time is 1~5h, the centrifugation speed is 3000~8000r / min, the centrifugation time is 5~20min, the vacuum freeze-drying time is 72~140h, and the size of the obtained coiled rod-shaped graphene oxide is 300~500nm with an aspect ratio of 30~50:

1. The organic solvent in step (2) is at least one of methanol, ethanol, and acetone; the coupling agent is at least one of aluminate coupling agent, titanate coupling agent, and silane coupling agent; the boron nitride solution contains boron nitride whiskers: organic solvent 1~5g: 300~600mL; the boron nitride whisker size is 50~200nm, and the aspect ratio is 50~100:1; the reaction temperature is 20~80℃, and the reaction time is 30~120min; The organic solvent mentioned in step (3) is at least one of methanol, ethanol, and acetone; the coupling agent is at least one of aluminate coupling agent, titanate coupling agent, and silane coupling agent; the ratio of the coiled rod-shaped graphene oxide: coupling agent: organic solvent: surface-treated boron nitride whiskers is 1~5g:0.05~0.15g:300~600mL:3~10g; the obtained wolf-tooth rod-shaped graphene-supported boron nitride whiskers have a special wolf-tooth rod-shaped structure with a size of 0.5~2μm and an aspect ratio of 10~20:

1.

2. A method for preparing thermally conductive TPV materials using boron nitride whiskers supported on wolf-tooth-shaped graphene as described in claim 1, characterized in that, The wolf-tooth-shaped graphene-supported boron nitride whiskers, TPV, and other processing aids are in a mass ratio of 10~20:60~80:10~20. The thermally conductive TPV material is obtained by melt extrusion granulation at 180~220℃. The other processing aids are compatibilizers, lubricants, and antioxidants.

3. A thermally conductive TPV material prepared by the method described in claim 2, characterized in that, The thermal conductivity of thermally conductive TPV material is ≥ 1.5 W / m·K.

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