Preparation technology of soft elastic heat-conducting fiber membrane
The core-sheaven structure TPU/BN-LMs fibers were prepared and braided by coaxial wet spinning technology, which solved the problem of insufficient thermal conductivity of polymer materials, and achieved TBLTB soft elastic thermal conductivity fibers with both high thermal conductivity and flexibility The film improves the thermal management performance of electronic components.
Patent Information
- Application Number
- CN202310694352.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-06-13
- Publication Date
- 2024-12-13
AI Technical Summary
The existing polymer polymer materials lack thermal conductivity in electronic components, making it difficult to meet the heat dissipation requirements of modern electronic equipment, and it is difficult to have both flexibility and high thermal conductivity.
Coaxial wet spinning technology was used to prepare TPU/BN-LMs fibers with core-sheath structures, forming a mesh braided body through fiber braiding, and filling TPU/BN in the voids to prepare a TBLTB soft elastic thermal fiber membrane.
It realizes a thermal interface material that combines high thermal conductivity and flexibility, improving the thermal management performance of electronic components and the reliability of battery temperature control.
Smart Images
Figure CN119121655A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to a preparation technology of a soft elastic heat-conducting fiber film, which can be used for thermal interface materials in electronic components and temperature thermal control of batteries, and belongs to the field of heat-conducting composite materials. Background Art
[0002] With the rapid development of portable devices and flexible devices, the power and integration of electronic components are constantly improving, and thermal management issues have gradually become one of the bottlenecks restricting the microelectronics industry. As the core component connecting the heat source and the heat dissipation structure, flexible high thermal conductivity thermal interface materials usually play a vital role in thermal management equipment, and therefore have broad market prospects. Polymer materials have the advantages of light weight, softness, easy processing, good mechanical properties, chemical corrosion resistance, electrical insulation, and low cost, and are widely used in various electronic devices. However, most polymers have low thermal conductivity and are difficult to meet the requirements of heat dissipation in modern electronic devices. Therefore, the preparation of polymer materials with both high thermal conductivity and flexibility is extremely innovative and challenging.
[0003] In recent years, flexible and highly thermally conductive polymer materials have attracted extensive attention due to their broad market prospects. Huang Xingyi's research group used a strategy combining coaxial electrospinning, electrostatic spraying and hot pressing to prepare a highly thermally conductive phase change nanocomposite (PCN) film with a core-sheath structure and a highly oriented interconnected boron nitride nanosheet (BNNS) network structure. Analysis showed that the core-sheath structure has a good encapsulation effect, prevents leakage of phase change components, and gives PCN excellent flexibility while maintaining a high phase change enthalpy; and the highly oriented BNNS interconnected network makes the PCN film exhibit an ultra-high in-plane thermal conductivity (28.3 W m - 1 K -1), however, the poor thermal conductivity of phase change materials and easy leakage at high temperatures limit their application. Zhang Nan's research group successfully prepared a new ternary composite phase change material composed of polyamide (PA), styrene-ethylene / propylene-styrene block copolymer (SEPS) and ethylene glycol (EG) through blending and impregnation. SEPS not only makes the composite material have a certain flexibility, but also cooperates with EG to form a layer-by-layer structure to confine liquid PA. EG was selected as a thermally conductive filler because of its good compatibility and absorption with PA. Before thermal stripping, the expandable graphite was pre-washed with deionized water and dried in a constant temperature oven at 65°C for about 24 hours. The new PA / SEPS / EG composite material has high thermal conductivity and good flexibility. It is a promising candidate material in the field of thermal management, but it still cannot overcome the disadvantages of the phase change material itself. By using coaxial wet spinning technology, thermoplastic polyurethane elastomer (TPU) doped with boron nitride (BN) was used as the sheath layer and liquid metal (LMs) was used as the core layer to prepare high thermal conductivity and high resilience thermoplastic polyurethane elastomer / boron nitride-liquid metal (TPU / BN-LMs) fibers with a core-sheath structure. The fibers were woven into a mesh braid, and TPU / BN was filled in the gaps to prepare a thermoplastic polyurethane elastomer / boron nitride-liquid metal / thermoplastic polyurethane elastomer-boron nitride (TBLTB) soft elastic thermal conductive fiber membrane with high thermal conductivity and resilience, which is an ideal flexible and high thermal conductivity thermal interface material. Summary of the invention
[0004] Using coaxial wet spinning technology, TPU / BN-LMs fibers with a core-sheath structure were prepared with BN-doped TPU as the sheath layer and LMs as the core layer. The fibers were woven into a mesh-like braided body, and TPU / BN was filled in the gaps to prepare the TBLTB soft elastic thermal conductive fiber membrane.
[0005] The technical purpose of the present invention is achieved through the following technical solutions.
[0006] A method for preparing a self-repairing boron nitride-polydimethylsiloxane thermally conductive composite material is carried out according to the following steps:
[0007] Step 1, Preparation of TPU / BN-LMs Fibers
[0008] Using the coaxial wet spinning method, TPU / BN spinning solution was injected into the No. I port of the spinneret, and liquid metal (LMs) was injected into the No. II port of the spinneret. The TPU / BN-LMs stream was pressed out from the spinneret hole and entered into the coagulation bath (silicone oil at a temperature of 85°C). When the TPU / BN-LMs stream reached the critical concentration, it precipitated in the silicone oil to form fibers. The obtained fibers were taken out of the silicone oil and dried at room temperature for 1 hour.
[0009] In step 1, the spinning speed was 0.5 cm s -1 The TPU / BN spinning solution flow rate was controlled at 1.0 mL min -1 , while the LMs flow rate is 0.5~1.0mL min -1 Changes between.
[0010] Step 2: Preparation of TPU / BN-LMs fiber braid
[0011] The single TPU / BN-LMs fiber is placed on a weaving board for plain weaving, that is, each fiber located at the weft line crosses with the fiber located at the warp line, and the warp line first passes over the weft line and then under it, and so on, thus obtaining a TPU / BN-LMs fiber braid with a mesh structure.
[0012] In step 2, the thermal conductivity of the braid along the plane direction is 9.9 to 10.1 W m -1 K -1 The thermal conductivity in the direction perpendicular to the braid is between 4.5 and 4.6 W m -1 K -1 Changes between.
[0013] Step 3, preparation of TBLTB soft elastic thermal conductive fiber membrane
[0014] The TPU / BN mixed liquid was evenly coated in the gaps of the TPU / BN-LMs fiber braid and left at room temperature for 2 hours. After it solidified, a TBLTB film was formed.
[0015] In step 3, the thickness of the TBLTB film varied between 3 and 5 mm.
[0016] The present invention uses thermoplastic polyurethane elastomer, boron nitride and liquid metal as raw materials, and synthesizes a high thermal conductivity and high resilience TPU / BN-LMs fiber composite material by coaxial wet spinning. The fibers are then woven into a mesh braided body, and TPU / BN is filled in the gaps to prepare a TBLTB soft elastic thermal conductive fiber membrane. The composite material solves the problem that the thermal interface material is difficult to have both flexibility and high thermal conductivity, ensures the reliability of the thermal management system, and provides a new solution for thermal management of electronic components and temperature control of batteries. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Figure 1 Diagram of the preparation process of TBLTB membrane.
[0018] Figure 2 This is a physical picture of TBLTB membrane.
[0019] Figure 3This is a temperature comparison chart of a primary battery coated with TBLTB and an ordinary primary battery. DETAILED DESCRIPTION
[0020] Three embodiments of the present invention are provided below to further illustrate the present invention, but not to limit the scope of the present invention.
[0021] Example 1
[0022] 1) Preparation of TPU / BN-LMs fibers: The wet coaxial spinning method was adopted. The No. I port of the spinneret was connected to the needle tube A containing 10 mL of TPU / BN spinning solution, and the No. II port of the spinneret was connected to the needle tube B containing 10 mL of liquid metal (LMs). The needle tubes were squeezed at the same time, and a thin stream of TPU / BN-LMs was pressed out from the spinneret hole into a coagulation bath (silicone oil at a temperature of 85°C) and precipitated to form fibers. The obtained fibers were taken out of the silicone oil and dried at room temperature for 1 h to obtain TPU / BN-LMs fibers.
[0023] 2) Preparation of TPU / BN-LMs fiber braid: A single TPU / BN-LMs fiber is placed on a weaving board for plain weaving. Each fiber at the weft crosses with the fiber at the warp. The fibers at the warp first pass over the fibers at the weft and then under them, and so on. In this way, a TPU / BN-LMs fiber braid with a mesh structure is obtained.
[0024] 3) Preparation of TBLTB soft elastic thermal conductive fiber membrane: 10 mL of TPU / BN mixed solution was evenly coated in the gaps of the TPU / BN-LMs fiber braid, and placed at room temperature for 2 hours. After it solidified, a TBLTB membrane with a thickness of 3 mm was formed.
[0025] Example 2
[0026] 1) Preparation of TPU / BN-LMs fibers: The wet coaxial spinning method was adopted. The No. I port of the spinneret was connected to the needle tube A containing 5 mL of TPU / BN spinning solution, and the No. II port of the spinneret was connected to the needle tube B containing 5 mL of liquid metal (LMs). The needle tubes were squeezed at the same time, and a thin stream of TPU / BN-LMs was pressed out from the spinneret hole into a coagulation bath (silicone oil at a temperature of 80°C) and precipitated to form fibers. The obtained fibers were taken out of the silicone oil and dried at room temperature for 1 hour to obtain TPU / BN-LMs fibers.
[0027] 2) Preparation of TPU / BN-LMs fiber braid: A single TPU / BN-LMs fiber is placed on a weaving board for plain weaving. Every two fibers at the weft and two fibers at the warp cross each other. The fibers at the warp first pass over the fibers at the weft and then under them, and so on. In this way, a TPU / BN-LMs fiber braid with a mesh structure is obtained.
[0028] 3) Preparation of TBLTB soft elastic thermal conductive fiber membrane: 15 mL of TPU / BN mixed solution was evenly coated in the gaps of the TPU / BN-LMs fiber braid, and placed at room temperature for 2 hours. After it solidified, a TBLTB membrane with a thickness of 4 mm was formed.
[0029] Example 3
[0030] 1) Preparation of TPU / BN-LMs fibers: 13.5 g of TPU was added to a beaker containing 37.5 g of DMF, and magnetic stirring was performed at 25 °C for 2 h to completely dissolve the TPU in DMF to obtain a precursor solution. Then 2.25 g of BN was dispersed in a mixed solvent of 22.5 g of DMF, ultrasonically treated for 1 h, and then added to the precursor solution. The mixture was stirred at room temperature for 12 h to obtain the TPU / BN spinning solution.
[0031] 2) Preparation of TPU / BN-LMs fiber braid: A single TPU / BN-LMs fiber is placed on a weaving board for plain weaving. Every three fibers at the weft and three fibers at the warp cross each other. The fibers at the warp first pass over the fibers at the weft and then under them, and so on. In this way, a TPU / BN-LMs fiber braid with a mesh structure is obtained.
[0032] 3) Preparation of TBLTB soft elastic thermal conductive fiber membrane: 20 mL of TPU / BN mixed solution was evenly coated in the gaps of the TPU / BN-LMs fiber braid, and placed at room temperature for 2 hours. After it solidified, a TBLTB membrane with a thickness of 5 mm was formed.
[0033] The present invention is described above by way of example. 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 those skilled in the art without inventive effort falls within the protection scope of the present invention.
Claims
1. A preparation technology of a soft elastic thermal conductive fiber membrane, characterized in that The preparation steps are as follows ： 1) Preparation of TPU / BN-LMs fibers: Using the coaxial wet spinning method, TPU / BN spinning solution was injected into the spinneret No. I, and liquid metal (LMs) was injected into the spinneret No. II. The TPU / BN-LMs stream was pressed out from the spinneret hole and entered into the coagulation bath (silicone oil at a temperature of 85°C). When the TPU / BN-LMs stream reached the critical concentration, it precipitated in the silicone oil to form fibers. The obtained fibers were taken out of the silicone oil and dried at room temperature for 1 hour. 2) Preparation of TPU / BN-LMs fiber braid: A single TPU / BN-LMs fiber is placed on a braiding board for plain weaving, that is, each fiber located in the weft crosses with the fiber located in the warp, and the warp first passes over the weft and then under it, and so on, thus obtaining a TPU / BN-LMs fiber braid with a mesh structure. 3) The TPU / BN mixed liquid was evenly coated in the gaps of the TPU / BN-LMs fiber braid and placed at room temperature for 2 hours. After it solidified, a TBLTB film was formed.
2. The preparation method according to claim 1, characterized in that The spinning speed in step 1) is 0.5 cm s -1 The TPU / BN spinning solution flow rate was controlled at 1.0 mL min -1 , while the LMs flow rate is 0.5~1.0mL min -1 Changes between.
3. The preparation method according to claim 1, characterized in that In step 2), the thermal conductivity of the braided body along the plane direction is between 9.9 and 10.1 W m -1 K -1 The thermal conductivity in the direction perpendicular to the braid is between 4.5 and 4.6 W m -1 K -1 Changes between.
4. The preparation method according to claim 1, characterized in that The thickness of the TBLTB film in step 3) varies between 3 and 5 mm.
5. A soft elastic thermally conductive fiber membrane composite material obtained according to the preparation method according to any one of claims 1 to 5.
6. An application of the soft elastic thermally conductive fiber film composite material according to claim 6 in thermal management of electronic components and temperature control of batteries.