A method for preparing a stretchable flexible thermal conductive material

Abstract

The invention discloses a preparation method of a stretchable flexible thermally conductive material, comprising the following steps: synthesizing P(M-PDA-EGDMA): placing EGDMA, M-PDA and an initiator in a container of N,N-dimethylformamide (DMF), introducing argon into the mixture, heating the mixture to 55-65°C and stirring, and polymerizing to obtain a reaction mixture; preparing P(M-PDA-EGDMA) / BN: dissolving a polymer P(M-PDA-EGDMA) in an ethyl acetate solution to obtain a polymer solution, adding a rod-shaped silver nanoparticle solution to the polymer solution, mixing uniformly, and forming a film using 3D printing to obtain a three-dimensional structure; freeze-drying to obtain a three-dimensional porous fiber; and filling the porous fiber with boron nitride nanoparticles, a high thermal conductivity filler, to prepare the stretchable flexible polymer thermally conductive material.

Description

Technical Field

[0001] The present invention relates to a preparation technology of a stretchable flexible thermally conductive material, which is mainly used in electronic heat dissipation, high-temperature management and equipment requiring flexible thermal conductivity, and belongs to the field of polymer functional composite materials. Background Art

[0002] The application of thermal conductive materials is crucial in electronic devices and high-tech fields. Traditional thermal conductive materials, such as metals (such as copper, aluminum) and ceramics (such as aluminum nitride, silicon nitride), although excellent in thermal conductivity, are usually highly rigid and lack flexibility, which limits their use in flexible electronic devices and other applications that require flexible shape adaptation. This limitation is particularly prominent in the design of modern electronic devices, such as flexible displays, wearable devices, and flexible circuit boards, which require materials that not only have high thermal conductivity but also maintain good performance under various operating conditions such as bending, stretching, or squeezing.

[0003] In recent years, as electronic devices have become thinner and more flexible, the demand for materials that combine thermal conductivity and flexibility has continued to increase. This demand has driven research into new thermally conductive materials, particularly those that can maintain high thermal conductivity while also possessing excellent flexibility and stretchability. For example, flexible thermally conductive materials such as thermally conductive silicone and thermally conductive polymer composites have begun to emerge and have, to a certain extent, addressed this technical challenge. However, these materials still face challenges, such as stability in high-temperature environments, uniformity of thermal conductivity, and performance degradation during long-term use.

[0004] Therefore, developing a new type of stretchable, flexible thermally conductive material that can maintain high thermal conductivity while also possessing excellent flexibility and durability has become an important research direction. This will not only help promote technological advancements in flexible electronic devices, but can also be applied to a wider range of fields, such as smart wearable devices, flexible sensors, and high-temperature management systems. Summary of the Invention

[0005] This invention provides a method for preparing a stretchable, flexible, thermally conductive material. Using P(M-PDA-EGDMA) as a polymer substrate and boron nitride (BN) as a highly thermally conductive filler, the material exhibits excellent thermal conductivity and flexibility, meeting the high material performance requirements of modern electronic devices. The technical objectives of this invention are achieved through the following technical solutions.

[0006] A method for preparing a stretchable flexible thermally conductive material comprises the following steps:

[0007] 1) Synthesis of P(M-PDA-EGDMA): EGDMA, M-PDA, and an initiator are placed in a container containing N,N-dimethylformamide (DMF) at a molar ratio of 3-methacryloyldopamine (M-PDA) to ethylene glycol dimethacrylate (EGDMA) of 2:(4.5-5.5). Argon is introduced into the mixture, and the mixture is heated to 55-65°C with stirring to polymerize and obtain a reaction mixture.

[0008] 2) Preparation of P(M-PDA-EGDMA) / BN: The polymer P(M-PDA-EGDMA) was dissolved in an ethyl acetate solution to obtain a polymer solution. A solution of rod-shaped silver nanoparticles was added to the solution, mixed evenly, and formed into a three-dimensional film using 3D printing. Three-dimensional porous fibers were obtained after freeze-drying. The porous fibers were then filled with boron nitride nanoparticles, a highly thermally conductive filler, to prepare a stretchable, flexible polymer thermally conductive material.

[0009] In step 1), the initiator may be aminocyanate ABCN or azobisisobutyronitrile AIBN.

[0010] In step 1), methanol is added to dilute the reaction mixture, and then diethyl ether is added to precipitate the polymer. The precipitation process is repeated 2-3 times to completely remove unreacted monomers and residual solvent.

[0011] The method is characterized in that the time for introducing argon in step 1) should be no less than 10 minutes.

[0012] The concentration of the polymer solution prepared in step 2) should be controlled within the range of 0.6 g / mL to 1.2 g / mL.

[0013] In step 2), a rod-shaped silver nanoparticle solution with a mass fraction of 5% can be added to the polymer solution.

[0014] In step 2), the product is freeze-dried at -70°C for 24 hours.

[0015] This invention provides a method for preparing a stretchable, flexible, thermally conductive material. Through precise material selection and optimized preparation processes, it achieves a combination of high thermal conductivity and excellent flexibility. This new material can meet the high performance requirements of modern electronic devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is the preparation scheme of P(M-PDA-EGDMA).

[0017] Figure 2 The invention relates to the filler structure and preparation scheme. DETAILED DESCRIPTION

[0018] Two embodiments of the present invention are given below to further illustrate the present invention, but not to limit the scope of the present invention.

[0019] Example 1

[0020] 1) Synthesis of P(M-PDA-EGDMA): EGDMA (6.5 g, 50 mmol), M-PDA (4.4 g, 20 mmol), and aminocyanate (ABCN) (152 mg, 0.92 mmol) were placed in a round-bottom flask containing 20 mL of N,N-dimethylformamide (DMF) at a molar ratio of 2:5. Argon was then bubbled through the mixture for 10 minutes. The solution was heated to 60°C and stirred for 12 hours for polymerization. The reaction mixture was then diluted with 20 mL of methanol, followed by precipitation of the polymer with 200 mL of diethyl ether. This precipitation process was repeated two to three times to completely remove unreacted monomer and residual solvent.

[0021] 2) Preparation of P(M-PDA-EGDMA) / BN: 5g of polymer P(M-PDA-EGDMA) was fully dissolved in 20g of ethyl acetate to obtain a 20% polymer solution. 5g of rod-shaped silver nanoparticle solution (5% by mass) was then added to the solution and stirred at 25°C for 2 hours to form a homogeneous solution. The resulting three-dimensional structure was then obtained by 3D printing. The principle of 3D printing is based on a layer-by-layer deposition process. The printer deposits a solution or molten material onto a substrate, forming each layer along a predetermined path. After each layer solidifies, the next layer is deposited, ultimately forming a three-dimensional structure. After standing for 1 hour, the hydrophobic phase and hydrophilic solvent in the system undergo phase separation, achieving initial solvent removal. Residual solvent was removed by freeze-drying at -70°C for 24 hours, resulting in three-dimensional porous fibers with uniform pore size. The porous fibers were then filled with boron nitride nanoparticles, a highly thermally conductive filler, to produce a stretchable, flexible, thermally conductive material.

[0022] Example 2

[0023] 1) Synthesis of P(M-PDA-EGDMA): EGDMA (6.5 g, 50 mmol), M-PDA (4.4 g, 20 mmol), and azobisisobutyronitrile (AIBN) (107 mg, 0.92 mmol) were placed in a round-bottom flask containing 20 mL of N,N-dimethylformamide (DMF) at a molar ratio of 2:5. Argon was then bubbled through the mixture for 10 minutes. The solution was heated to 60°C and stirred for 12 hours for polymerization. The reaction mixture was then diluted with 20 mL of methanol, followed by precipitation of the polymer with 200 mL of diethyl ether. This precipitation process was repeated two to three times to completely remove unreacted monomer and residual solvent.

[0024] 2) Preparation of P(M-PDA-EGDMA) / BN: 5g of polymer P(M-PDA-EGDMA) was fully dissolved in 20g of DMF to obtain a 20% polymer solution. A 5% solution of rod-shaped silver nanoparticles was added to the solution and stirred at 25°C for 2 hours to form a homogeneous solution. The resulting three-dimensional structure was then obtained by 3D printing. The principle of 3D printing is based on a layer-by-layer deposition process. The printer deposits a solution or molten material onto a substrate, forming each layer along a predetermined path. After each layer solidifies, the next layer is deposited, ultimately forming a three-dimensional structure. After standing for 1 hour, the hydrophobic phase and hydrophilic solvent in the system undergo phase separation, achieving initial solvent removal. Residual solvent was removed by freeze-drying at -70°C for 24 hours, resulting in three-dimensional porous fibers with uniform pore size. The porous fibers were then filled with boron nitride nanoparticles, a highly thermally conductive filler, to produce a stretchable, flexible, thermally conductive material.

[0025] The above is an exemplary description of the present invention. It should be noted that, without departing from the core of the present invention, any simple deformation, modification or other equivalent replacement that can be made by other skilled in the art without expending creative labor falls within the scope of protection of the present invention.

Claims

1. A method for preparing a stretchable flexible thermally conductive material, comprising the following steps: 1) Synthesis of P(M-PDA-EGDMA): EGDMA, M-PDA, and an initiator are placed in a container containing N,N-dimethylformamide (DMF) at a molar ratio of 3-methacryloyldopamine (M-PDA) to ethylene glycol dimethacrylate (EGDMA) of 2:(4.5-5.5). Argon is introduced into the mixture, and the mixture is heated to 55-65°C with stirring to polymerize and obtain a reaction mixture. 2) Preparation of P(M-PDA-EGDMA) / BN: The polymer P(M-PDA-EGDMA) was dissolved in an ethyl acetate solution to obtain a polymer solution. A solution of rod-shaped silver nanoparticles was added to the solution, mixed evenly, and formed into a three-dimensional film using 3D printing. Three-dimensional porous fibers were obtained after freeze-drying. The porous fibers were then filled with boron nitride nanoparticles, a highly thermally conductive filler, to prepare a stretchable, flexible polymer thermally conductive material.

2. The preparation method according to claim 1, wherein In step 1), the initiator is aminocyanate ABCN or azobisisobutyronitrile AIBN.

3. The preparation method according to claim 1, wherein In step 1), methanol is added to dilute the reaction mixture, and then diethyl ether is added to precipitate the polymer.

4. The preparation method according to claim 1, wherein The time for introducing argon in step 1) is 10 min.

5. The preparation method according to claim 1, wherein The concentration of the polymer solution prepared in step 2) is controlled at 0.6 g / mL to 1.2 g / mL.

6. The preparation method according to claim 1, wherein In step 2), a rod-shaped silver nanoparticle solution with a mass fraction of 5% is added to the polymer solution.

7. The preparation method according to claim 1, wherein In step 2), freeze-dry at -70°C for 24 h.

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