Natural rubber-based core-shell structure micro-nano fiber composite material as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of temperature control materials, and particularly relates to a natural rubber-based core-shell structure micro-nanofiber composite material and a preparation method and application thereof. The invention provides a natural rubber-based core-shell structure micro-nano fiber composite material. The natural rubber-based core-shell structure micro-nano fiber composite material comprises a core layer and a shell layer wrapping the surface of the core layer, the material of the core layer comprises a phase change material; and the material of the shell layer comprises natural rubber and a heat-conducting filler. The natural rubber-based core-shell structure micro-nanofiber composite material provided by the invention belongs to a core-shell structure, takes a phase change material as a core layer, and shows solid phase characteristics at room temperature; natural rubber is used as a shell layer, high elasticity is shown, and large deformation can be generated even if the stress is very small. In the specific application process, when the temperature reaches the phase change temperature of the phase change material in the core layer, the core layer material is converted from a solid phase to a liquid phase, and the stress borne by the core layer material enables the shell layer to generate large deformation, so that the strain change is obtained, and the purpose of control is achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of temperature control materials, and in particular relates to a natural rubber-based core-shell structured micro-nano fiber composite material, a preparation method thereof, and applications thereof. Background Art

[0002] Lithium-ion battery overheating is a significant safety concern because excessive heat can cause the chemical reactions within the battery to spiral out of control, triggering thermal runaway and potentially causing an explosion or fire. Therefore, lithium-ion battery designs often incorporate a thermal switch or protection circuit to prevent overheating. A thermal switch is a safety device that monitors the battery's temperature and, if it reaches a certain threshold, cuts off the battery's output or shuts down the battery. This threshold is typically set within a safe range to effectively prevent overheating and preserve the battery's lifespan.

[0003] Temperature control switches are a series of automatic control components that produce certain special effects and turn on or off according to the temperature changes of the working environment, causing deformation inside the switch. Or they are electronic components that work in different states at different temperatures to provide temperature data to the circuit for the circuit to collect temperature data.

[0004] Existing temperature control switches are mainly metal temperature control switches, which are expensive and have poor flexibility, and are not suitable for wearable and online medical fields. Summary of the Invention

[0005] The present invention aims to provide a natural rubber-based core-shell micro-nano fiber composite material and its preparation method and application. The natural rubber-based core-shell micro-nano fiber composite material provided by the present invention has low cost and good flexibility.

[0006] In order to achieve the above object, the present invention provides the following technical solutions:

[0007] The present invention provides a natural rubber-based core-shell structured micro-nano fiber composite material, comprising a core layer and a shell layer wrapped around the surface of the core layer;

[0008] The material of the core layer includes phase change material;

[0009] The material of the shell layer includes natural rubber and thermal conductive filler.

[0010] Preferably, the diameter of the core layer is 0.5 to 1.0 μm;

[0011] The average diameter of the natural rubber-based core-shell structured micro-nano fiber composite material is 2-5 μm.

[0012] Preferably, the melting point of the phase change material is 30-50°C.

[0013] Preferably, the phase change material comprises at least one of aliphatic alkanes, fatty alcohols and fatty acids;

[0014] The aliphatic alkane includes at least one of tridecane, tetradecane, pentadecane and hexadecane;

[0015] The fatty alcohol comprises at least one of lauryl alcohol, tridecanol, tetradecanol, pentadecanol and hexadecanol;

[0016] The fatty acid includes at least one of capric acid, lauric acid, myristic acid, palmitic acid and stearic acid.

[0017] Preferably, the thermally conductive filler comprises at least one of nanosilver, alumina, aluminum nitride, boron nitride and silicon nitride;

[0018] The mass ratio of the natural rubber to the thermal conductive filler is 10:0.5-2.

[0019] The present invention also provides a method for preparing the natural rubber-based core-shell structured micro-nano fiber composite material described in the above technical solution, comprising the following steps:

[0020] providing a dispersion containing a core layer material and a dispersion containing a shell layer material respectively;

[0021] The dispersion containing the core layer material and the dispersion containing the shell layer material are coaxially spun to obtain the natural rubber-based core-shell structured micro-nano fiber composite material.

[0022] Preferably, the dispersion containing the core layer material comprises a phase change material and a first organic solvent, wherein the first organic solvent comprises ethanol; and the usage ratio of the phase change material to the first organic solvent is 5-10 g:10-20 mL.

[0023] Preferably, the dispersion liquid containing the shell layer material comprises natural rubber, a thermally conductive filler and a second organic solvent, wherein the second organic solvent comprises tetrahydrofuran; and the usage ratio of the natural rubber to the second organic solvent is 5-10 g:10-20 mL.

[0024] Preferably, the conditions for the coaxial co-spinning include: an electrostatic voltage of 10 to 20 kV, an aluminum foil receiving plate, a plate spacing of 15 to 35 cm, and a diameter ratio of the spinning needles of the core layer and the shell layer of 1:2 to 8:9.

[0025] The present invention also provides the use of the natural rubber-based core-shell structured micro-nano fiber composite material described in the above technical solution or the natural rubber-based core-shell structured micro-nano fiber composite material prepared by the preparation method described in the above technical solution as a temperature control switch.

[0026] The present invention provides a natural rubber-based core-shell structured micro-nano fiber composite material, comprising a core layer and a shell layer wrapped around the surface of the core layer; the material of the core layer comprises a phase change material; the material of the shell layer comprises natural rubber and a thermal conductive filler.

[0027] The natural rubber-based core-shell micro-nanofiber composite material provided by the present invention has a core-shell structure. Its core layer, a phase-change material, exhibits solid-phase characteristics at room temperature. Its shell layer, a natural rubber layer, exhibits high elasticity, allowing even small stresses to produce large deformations. In specific applications, when the temperature reaches the phase transition temperature of the phase-change material in the core layer, the core material transforms from a solid to a liquid phase. The resulting stress causes the shell layer to undergo large deformations, resulting in a change in strain, achieving controllable strain.

[0028] The natural rubber-based core-shell structured micro-nano fiber composite material provided by the present invention has low cost, good flexibility and is lighter, and is suitable for the fields of smart wearables and online medical care. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a schematic structural diagram of the natural rubber-based core-shell structured micro-nano fiber composite material provided by the present invention. DETAILED DESCRIPTION

[0030] The present invention provides a natural rubber-based core-shell structured micro-nano fiber composite material, comprising a core layer and a shell layer wrapped around the surface of the core layer;

[0031] The material of the core layer includes phase change material;

[0032] The material of the shell layer includes natural rubber and thermal conductive filler.

[0033] In the present invention, the melting point of the phase change material is preferably 30-50°C; the phase change material preferably includes at least one of aliphatic alkanes, fatty alcohols, and fatty acids; the aliphatic alkanes preferably include at least one of tridecane, tetradecane, pentadecane, and hexadecane; the fatty alcohols preferably include at least one of dodecanol, tridecanol, tetradecanol, pentadecane, and hexadecanol; the fatty acids preferably include at least one of capric acid, lauric acid, myristic acid, palmitic acid, and stearic acid. In the present invention, the diameter of the core layer is preferably 0.1-1.0 μm, specifically 0.1 μm, 0.2 μm, 0.3 μm, 0.4 μm, 0.5 μm, 0.6 μm, 0.7 μm, 0.8 μm, 0.9 μm, or 1.0 μm.

[0034] In the present invention, the thermally conductive filler preferably includes at least one of nanosilver, aluminum oxide, aluminum nitride, boron nitride, and silicon nitride. The mass ratio of the natural rubber to the thermally conductive filler is preferably 10:0.5 to 2, specifically 10:0.5, 10:1.0, 10:1.5, or 10:2.0. In the present invention, the purpose of adding the thermally conductive filler to the shell layer is to accelerate heat conduction, thereby rapidly dissipating heat.

[0035] In the present invention, the average diameter of the natural rubber-based core-shell structured micro-nano fiber composite material is preferably 2-5 μm, specifically 2 μm, 3 μm, 4 μm, or 5 μm.

[0036] The structural diagram of the natural rubber-based core-shell structure micro-nano fiber composite material provided by the present invention is as follows Figure 1 shown.

[0037] The present invention also provides a method for preparing the natural rubber-based core-shell structured micro-nano fiber composite material described in the above technical solution, comprising the following steps:

[0038] providing a dispersion containing a core layer material and a dispersion containing a shell layer material respectively;

[0039] The dispersion containing the core layer material and the dispersion containing the shell layer material are coaxially spun to obtain the natural rubber-based core-shell structured micro-nano fiber composite material.

[0040] The present invention provides a dispersion containing a core layer material and a dispersion containing a shell layer material respectively.

[0041] In the present invention, the dispersion containing the core layer material preferably includes a phase change material and a first organic solvent, and the first organic solvent preferably includes ethanol; the usage ratio of the phase change material to the first organic solvent is preferably 5-10 g:10-20 mL.

[0042] In the present invention, the shell material-containing dispersion preferably includes natural rubber, a thermally conductive filler, and a second organic solvent, preferably tetrahydrofuran. The ratio of the natural rubber to the second organic solvent is preferably 5-10 g:10-20 mL. In the present invention, the shell material-containing dispersion also preferably includes a sodium chloride solution, preferably at a concentration of 1% by mass. The volume ratio of the second organic solvent to the sodium chloride solution is preferably 20:0.5. In the present invention, the addition of the sodium chloride solution to the shell material-containing dispersion improves the spinnability of the dispersion.

[0043] In the present invention, the method for preparing the dispersion containing the shell layer material preferably includes: chopping natural rubber and dissolving it in a second organic solvent, adding a thermally conductive filler and a sodium chloride solution while stirring, and then ultrasonicating the obtained system in a sealed state; the ultrasonic time is preferably 20 to 30 minutes.

[0044] In the present invention, the coaxial co-spinning conditions preferably include: an electrostatic voltage of 10 to 20 kV, an aluminum foil receiving plate, a plate spacing of 15 to 35 cm, more preferably 25 cm, and a core layer to shell layer spinning needle diameter ratio of 1:2 to 8:9, more preferably 4:5. In the present invention, the volume ratio of the core layer material dispersion to the shell layer material dispersion is preferably 1:3 to 2:1.

[0045] The present invention also provides the use of the natural rubber-based core-shell structured micro-nano fiber composite material described in the above technical solution or the natural rubber-based core-shell structured micro-nano fiber composite material prepared by the preparation method described in the above technical solution as a temperature control switch.

[0046] Unless otherwise specified, the materials and equipment used in the present invention are all commercially available products in the art.

[0047] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions of the present invention. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0048] Example 1

[0049] 5g of natural rubber was chopped and dissolved in 20mL of tetrahydrofuran. 0.5g of nanosilver and 0.5mL of a 1% sodium chloride aqueous solution were added under stirring. Ultrasonic treatment was performed in a sealed state for 30 minutes before spinning. 10mL of the shell dispersion was extracted from a glass syringe for spinning. 10g of tridecane was dissolved in 10mL of ethanol to obtain a core dispersion. 10mL of the core dispersion was extracted from the syringe for spinning. Coaxial co-spinning was carried out at an electrostatic voltage of 10kV, with a plate spacing of 25cm and an aluminum foil receiving plate. The inner diameters of the core and shell spinning needles were 0.2mm and 0.25mm, respectively. The average diameter of the obtained natural rubber-based core-shell structured micro-nanofiber composite material was 2.8μm.

[0050] The natural rubber-based core-shell structured micro-nano fiber composite material obtained in this example has an induction temperature of 31° C., a temperature control error range of ±0.3° C., and a thermal conductivity of 5.13 W / m·K.

[0051] Example 2

[0052] 5g of natural rubber was chopped and dissolved in 20mL of tetrahydrofuran. 0.5g of alumina and 0.5mL of a 1% sodium chloride aqueous solution were added under stirring. Ultrasonic treatment was performed in a sealed state for 30 minutes before spinning. 10mL of the shell dispersion was drawn out from a glass syringe for spinning. 10g of dodecanol was dissolved in 20mL of ethanol, and 10mL of the core dispersion was drawn out from a syringe for spinning. Coaxial co-spinning was carried out at an electrostatic voltage of 12kV, with a plate spacing of 25cm and an aluminum foil receiving plate. The inner diameters of the core and shell spinning needles were 0.2mm and 0.25mm, respectively. The average diameter of the obtained natural rubber-based core-shell structured micro-nanofiber composite material was 2.5μm.

[0053] The natural rubber-based core-shell structured micro-nano fiber composite material obtained in this example has an induction temperature of 26° C., a temperature control error range of ±0.1° C., and a thermal conductivity of 7.81 W / m·K.

[0054] Example 3

[0055] 5g of natural rubber was chopped and dissolved in 20mL of tetrahydrofuran. 0.5g of aluminum nitride and 0.5mL of a 1% sodium chloride aqueous solution were added under stirring. Ultrasonic treatment was performed in a sealed state for 30 minutes before spinning. 10mL of the shell dispersion was drawn out from a glass syringe for spinning. 10g of lauric acid was dissolved in 20mL of ethanol, and 10mL of the core dispersion was drawn out from a syringe for spinning. Coaxial co-spinning was carried out at an electrostatic voltage of 15kV, with a plate spacing of 25cm and an aluminum foil receiving plate. The inner diameters of the core and shell spinning needles were 0.2mm and 0.25mm, respectively. The average diameter of the obtained natural rubber-based core-shell structured micro-nanofiber composite material was 2.2μm.

[0056] The natural rubber-based core-shell structured micro-nano fiber composite material obtained in this example has an induction temperature of 45° C., a temperature control error range of ±0.3° C., and a thermal conductivity of 8.17 W / m·K.

[0057] Although the above embodiment provides a detailed description of the present invention, it is only a part of the embodiments of the present invention, not all of the embodiments. Other embodiments can be obtained based on this embodiment without creativity, and these embodiments all fall within the scope of protection of the present invention.

Claims

1. A natural rubber-based core-shell structured micro-nano fiber composite material, characterized in that: It comprises a core layer and a shell layer wrapped around the surface of the core layer; The material of the core layer includes phase change material; The material of the shell layer includes natural rubber and thermal conductive filler.

2. The natural rubber-based core-shell structured micro-nano fiber composite material according to claim 1, characterized in that: The diameter of the core layer is 0.5 to 1.0 μm; The average diameter of the natural rubber-based core-shell structured micro-nano fiber composite material is 2-5 μm.

3. The natural rubber-based core-shell structured micro-nano fiber composite material according to claim 1, characterized in that: The melting point of the phase change material is 30-50°C.

4. The natural rubber-based core-shell structured micro-nano fiber composite material according to claim 3, characterized in that: The phase change material includes at least one of aliphatic alkanes, aliphatic alcohols and fatty acids; The aliphatic alkane includes at least one of tridecane, tetradecane, pentadecane and hexadecane; The fatty alcohol comprises at least one of lauryl alcohol, tridecanol, tetradecanol, pentadecanol and hexadecanol; The fatty acid includes at least one of capric acid, lauric acid, myristic acid, palmitic acid and stearic acid.

5. The natural rubber-based core-shell structured micro-nano fiber composite material according to claim 1, characterized in that: The thermally conductive filler comprises at least one of nano silver, aluminum oxide, aluminum nitride, boron nitride and silicon nitride; The mass ratio of the natural rubber to the thermal conductive filler is 10:0.5-2.

6. The method for preparing the natural rubber-based core-shell structured micro-nano fiber composite material according to any one of claims 1 to 5, characterized in that: The following steps are involved: providing a dispersion containing a core layer material and a dispersion containing a shell layer material respectively; The dispersion containing the core layer material and the dispersion containing the shell layer material are coaxially spun to obtain the natural rubber-based core-shell structured micro-nano fiber composite material.

7. The preparation method according to claim 6, characterized in that The core layer material-containing dispersion comprises a phase change material and a first organic solvent, wherein the first organic solvent comprises ethanol; the usage ratio of the phase change material to the first organic solvent is 5-10 g:10-20 mL.

8. The preparation method according to claim 6, characterized in that The dispersion liquid containing the shell layer material includes natural rubber, a thermal conductive filler and a second organic solvent, wherein the second organic solvent includes tetrahydrofuran; the usage ratio of the natural rubber and the second organic solvent is 5-10 g:10-20 mL.

9. The preparation method according to claim 6, characterized in that The coaxial spinning conditions include: static voltage of 10 to 20 kV, aluminum foil as the receiving plate, plate spacing of 15 to 35 cm, and a diameter ratio of the spinning needles of the core layer and the shell layer of 1:2 to 8:

9.

10. Use of the natural rubber-based core-shell structured micro-nano fiber composite material according to any one of claims 1 to 5 or the natural rubber-based core-shell structured micro-nano fiber composite material prepared by the preparation method according to any one of claims 6 to 9 as a temperature control switch.

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