A flexible functional composite material with excellent thermal management capabilities and its preparation method
By introducing the synergistic effect of PDMS matrix, h-BN thermally conductive phase, and MPCM thermal storage phase into flexible composite materials, the problems of heat dissipation capacity and phase change material leakage are solved, achieving efficient thermal management and excellent mechanical properties.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- TONGJI UNIV
- Filing Date
- 2025-11-13
- Publication Date
- 2026-05-26
AI Technical Summary
Existing flexible composite materials suffer from poor heat dissipation, low heat absorption efficiency of phase change materials, and insufficient mechanical compliance in terms of thermal management. In particular, leakage of phase change materials is prone to occur at high filler concentrations.
A matrix material was prepared by mixing PDMS prepolymer with a crosslinking agent, and MPCM powder and h-BN powder were added. Through magnetic stirring, vacuum degassing and gradient heating, a flexible functional composite material with uniformly distributed thermal conductive phase and thermal storage phase was prepared. The high thermal conductivity of h-BN and the phase change characteristics of MPCM were utilized to achieve synergistic heat dissipation and heat absorption.
It improves the overall thermal conductivity and heat absorption efficiency of the material, enhances mechanical properties, reduces the leakage risk of phase change materials, and achieves excellent thermal management and mechanical properties.
Smart Images
Figure CN121108745B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of thermal management and heat harvesting technology, specifically to a flexible functional composite material with excellent thermal management capabilities and its preparation method. Background Technology
[0002] As new electronic devices evolve towards miniaturization, integration, and high power, the current-induced thermal effect becomes more pronounced, leading to performance degradation and even failure. Therefore, temperature control is crucial. Statistics show that for every 10-degree Celsius increase in temperature, the reliability of electronic devices decreases by 50%, while for every 1-degree Celsius decrease, the failure rate decreases by 4%. Over 50% of failures are caused by inadequate thermal management of electronic devices. Furthermore, some electronic devices are worn on the skin to provide unique functions, such as physiological signal monitoring, communication, and energy utilization. These devices continuously generate heat during operation due to the current-induced thermal effect, while the human body's core temperature needs to be maintained between 30-34°C to ensure optimal cellular function and homeostasis. Excessive heat generated by electronic devices can cause discomfort and even burns.
[0003] Thermal management materials can mitigate the effects of high temperatures on equipment or personnel through various means such as thermal buffering and heat dissipation, and are widely used in fields such as electronic chips, advanced textiles, energy-efficient buildings, and electronic skin. However, material leakage, poor heat dissipation capacity, poor thermal buffering capacity, and poor mechanical compliance remain several major problems restricting their development. Therefore, designing and manufacturing functional composite materials with excellent thermal and mechanical properties is of great significance.
[0004] The published patent "Thermotropic Flexible Composite Phase Change Material Coupled with Multiple Crosslinked Network Aerogel Material and Its Thermal Protection Application" (CN119144298A) describes a composite phase change material mainly composed of multiple crosslinked network aerogel, thermotropic flexible composite phase change material, and binder, exhibiting good thermal insulation and flame retardancy. Similar to this invention, the composite material includes a matrix phase and a thermal storage phase, but does not include a thermally conductive phase material, which may result in poor overall heat dissipation capacity of the composite material and low heat absorption efficiency of the phase change material.
[0005] The published patent "A Preparation Method of a Phase Change Microcapsule Composite Ablation Thermal Protection Material" (CN118791761A) describes the preparation of phase change microcapsules, their mixing with resin monomers, and coating the mixture onto fiber fabric to obtain a phase change microcapsule composite ablation material. This method solves the problem of poor compatibility between existing phase change microcapsules and resin matrices. Similar to this invention, both use phase change microcapsules as the heat-absorbing material, which can effectively reduce phase change material leakage. However, both do not contain a thermally conductive phase material, which may result in poor overall heat dissipation capacity of the composite material and low heat absorption efficiency of the phase change material. Furthermore, neither invention addresses material preparation strategies for high filler concentrations.
[0006] The published patent "A Flexible Insulating Organosilicon Thermal Management Composite Material Based on Phase Change Material and Its Preparation Method" (CN120310275A) describes a composite material mainly composed of silicone rubber, paraffin wax, polyethylene glycol, and other phase change materials, as well as various thermally conductive fillers such as alumina and carbon nanotubes, and flame retardants. It boasts advantages such as low leakage rate and good thermal conductivity. Similar to this invention, both composite materials contain a matrix phase, a thermal storage phase, and a thermally conductive phase material. However, the phase change material is only encapsulated by silicone rubber, which may lead to leakage issues. Furthermore, the thermally conductive filler is electrically conductive, potentially affecting the insulation properties of the composite material.
[0007] The published patent "Preparation Method of Polyurethane-Based Flexible Phase Change Material and Battery Thermal Management Device" (CN12024820A) uses polyethylene glycol as the phase change material and polyurethane as the matrix material, combined with a crosslinking agent to prepare a flexible composite material suitable for battery thermal management. Similar to this invention, the composite materials all contain a matrix phase and a thermal storage phase, but do not contain a thermally conductive phase material, which may result in poor overall heat dissipation capacity of the composite material and low heat absorption efficiency of the phase change material. Summary of the Invention
[0008] This invention is made to solve the above-mentioned problems, and aims to provide a flexible functional composite material with excellent thermal management capabilities and its preparation method.
[0009] This invention provides a method for preparing a flexible functional composite material with excellent thermal management capabilities, characterized by the following steps: S1, mixing PDMS prepolymer and crosslinking agent in a certain proportion and stirring thoroughly to obtain a PDMS solution; mixing MPCM powder and h-BN powder in a certain proportion and stirring thoroughly to obtain a powder mixture; S2, adding the powder mixture to the PDMS solution to obtain a first mixture; subsequently adding n-hexane and magnetically stirring to obtain a second mixture; S3, allowing the second mixture to stand for a period of time and then degassing under vacuum to obtain a third mixture; S4, slowly pouring the third mixture into a mold and using external force to vibrate and level the mixture to fill the mold; S5, placing the mold in an oven for gradient heating to obtain a flexible functional composite material with excellent mechanical and thermal management properties.
[0010] The method for preparing a flexible functional composite material with excellent thermal management capabilities provided by the present invention may also have the following characteristics: wherein the ratio of PDMS prepolymer to crosslinking agent is (9~11):1, the mass fraction of MPCM powder is 25-50%wt, the mass fraction of h-BN powder is not greater than 25%wt, the average particle size of MPCM powder is 20~30μm, its phase transition temperature is 37℃, and the average particle size of h-BN powder is 20~30μm.
[0011] The method for preparing a flexible functional composite material with excellent thermal management capabilities provided by the present invention may also have the following characteristics: in step S2, the magnetic stirring rate is 1800-2200 rpm and the time is 0.5-1.5h.
[0012] The method for preparing a flexible functional composite material with excellent thermal management capabilities provided by the present invention may also have the following characteristics: in step S3, the standing time is 10-20 min and the vacuum degassing time is 25-35 min.
[0013] The method for preparing a flexible functional composite material with excellent thermal management capabilities provided by the present invention may also have the following feature: wherein, in step S4, the thickness of the mold is 0.5 mm to 1.5 mm.
[0014] The method for preparing a flexible functional composite material with excellent thermal management capabilities provided by the present invention may also have the following features: wherein, in S5, the gradient heating includes a first stage, a second stage and a third stage, the heating temperature of the first stage is 40-50℃ and the heating time is 2-4h; the heating temperature of the second stage is 80-90℃ and the heating time is 1-3h; the heating temperature of the third stage is 110-120℃ and the heating time is 0.5-1.5h.
[0015] The present invention also provides a flexible functional composite material with excellent thermal management capabilities, characterized in that it is prepared according to the above-described method for preparing a flexible functional composite material with excellent thermal management capabilities.
[0016] The flexible functional composite material with excellent thermal management capabilities provided by the present invention may also have the following characteristics: it includes the following components: PDMS matrix material, h-BN thermal conductive material, melamine-formaldehyde resin as shell material and n-eicosane as core material MPCM thermal storage material.
[0017] The role and effect of invention
[0018] According to the flexible functional composite material with excellent thermal management capabilities and its preparation method, the present invention proposes a functional composite material with excellent thermal buffering performance, heat dissipation performance, mechanical compliance and low leakage.
[0019] The thermally conductive phase and the thermally stored phase in the functional composite material of this invention enhance the thermal management performance of the material through synergistic heat dissipation. Both phases are uniformly distributed within the matrix material. The thermally conductive phase can rapidly transfer heat, not only improving the overall thermal conductivity of the composite material but also quickly transferring heat to the thermally stored phase, thus increasing the material's heat absorption efficiency. The thermally conductive phase improves heat dissipation efficiency, while the thermally stored phase rapidly absorbs heat, reducing the surface temperature of the object. Their synergistic effect facilitates rapid temperature control of the object.
[0020] This invention proposes a simple and efficient preparation method for high-filler-concentration functional composite materials based on the crosslinking inhibition mechanism of PDMS and melamine-formaldehyde resin combined with external force constraint. The method involves only stirring, molding, and curing. The prepared composite material exhibits good molding quality, a smooth and defect-free surface, and excellent mechanical and thermal properties.
[0021] The flexible functional composite material prepared by this invention can still withstand large tensile deformation under 720° torsion. By adjusting the material ratio, the overall thermal conductivity of the material can reach up to 0.886 W / (m·K), and the latent heat can reach up to 82.5 J / g. The appropriate filler ratio can be selected according to different application scenarios. Attached Figure Description
[0022] Figure 1 This is a schematic diagram of the structure of the flexible functional composite material in an embodiment of the present invention.
[0023] Figure 2 These are torsion and tensile physical images of the flexible functional composite material in the embodiments of the present invention.
[0024] Figure 3 These are the stress-strain curves of the flexible functional composite materials prepared in Examples 1-5 of this invention.
[0025] Figure 4 These are the heat flow curves of the flexible functional composite materials prepared in Examples 1-5 of this invention.
[0026] Figure 5 This is a schematic diagram of the latent heat of the flexible functional composite materials prepared in Examples 1-5 of the present invention.
[0027] Figure 6 This is a schematic diagram of the overall thermal conductivity of the flexible functional composite materials prepared in Examples 1-5 of the present invention. Detailed Implementation
[0028] To make the technical means, creative features, objectives and effects of the present invention easy to understand, the following embodiments, in conjunction with the accompanying drawings, specifically illustrate the flexible functional composite material with excellent thermal management capabilities and its preparation method.
[0029] Example 1
[0030] This embodiment discloses a method for preparing a flexible functional composite material with excellent thermal management capabilities, specifically including the following steps:
[0031] S1. Mix the PDMS prepolymer and crosslinking agent in a beaker at a mass ratio of 10:1 and stir thoroughly to obtain a PDMS solution. Weigh 4g of MPCM powder using weighing paper as the powder mixture.
[0032] S2, 4g of powder mixture is added to 4g of PDMS solution to obtain the first mixture, then n-hexane solution is added and magnetically stirred at 2000 rpm for 1 hour to obtain the second mixture.
[0033] S3. After the second mixture is left to stand for 15 minutes, it is placed in a vacuum degassing machine for 30 minutes to obtain the third mixture.
[0034] S4. Slowly pour the third mixture into the mold and use external force to vibrate it to make the third mixture flow fully and fill the mold.
[0035] S5. The mold is placed in an oven for gradient heating, cured at 45°C for 3 hours, at 85°C for 2 hours, and at 115°C for 1 hour, finally obtaining a flexible functional composite material with excellent mechanical properties and thermal management properties.
[0036] Example 2
[0037] Compared with Example 1, step S1 in this embodiment is replaced with "S1, mix PDMS prepolymer and crosslinking agent in a beaker at a mass ratio of 10:1 and stir thoroughly to obtain PDMS solution, weigh 3.5g of MPCM powder and 0.5g of h-BN powder with weighing paper, put them into the beaker and stir thoroughly to obtain 4g of powder mixture".
[0038] Example 3
[0039] Compared with Example 1, this embodiment replaces step S1 with "S1, mix PDMS prepolymer and crosslinking agent in a beaker at a mass ratio of 10:1 and stir thoroughly to obtain PDMS solution, weigh 3g of MPCM powder and 1g of h-BN powder with weighing paper and put them into the beaker and stir thoroughly to obtain 4g of powder mixture".
[0040] Example 4
[0041] Compared with Example 1, step S1 in this embodiment is replaced with "S1, mix PDMS prepolymer and crosslinking agent in a beaker at a mass ratio of 10:1 and stir thoroughly to obtain PDMS solution, weigh 2.5g of MPCM powder and 1.5g of h-BN powder with weighing paper and put them into the beaker and stir thoroughly to obtain 4g of powder mixture".
[0042] Example 5
[0043] Compared with Example 1, step S1 in this embodiment is replaced with "S1, mix PDMS prepolymer and crosslinking agent in a beaker at a mass ratio of 10:1 and stir thoroughly to obtain PDMS solution, weigh 2g of MPCM powder and 2g of h-BN powder with weighing paper and put them into the beaker and stir thoroughly to obtain 4g of powder mixture".
[0044] Figure 1 This is a schematic diagram of the structure of the flexible functional composite material in an embodiment of the present invention.
[0045] like Figure 1 As shown, the prepared flexible functional composite material uses PDMS as the matrix, MPCM as the thermal storage phase material, and h-BN as the thermally conductive phase material.
[0046] Figure 2 These are torsion and tensile physical images of the flexible functional composite material in the embodiments of the present invention.
[0047] like Figure 2 The image shown is a physical picture of the prepared flexible functional composite material. As can be seen from the image, the prepared material has a smooth, defect-free surface and can still withstand large tensile deformations under 720° torsional deformation.
[0048] Figure 3These are the stress-strain curves of the flexible functional composite materials prepared in Examples 1-5 of this invention.
[0049] like Figure 3 The figure shows the stress-strain curves for all embodiments. As can be seen from the figure, the elongation at break for Embodiments 1, 2, 3, 4, and 5 are 100.9%, 128.6%, 165.6%, 177.3%, and 183.4%, respectively. It is evident that as the proportion of h-BN increases, the mechanical properties gradually improve, and the elongation at break of the material gradually increases. Since h-BN is a rigid filler with excellent mechanical strength, when the flexible substrate is subjected to tensile force, the load can be effectively transferred from the PDMS matrix to the h-BN to prevent crack formation, resulting in an improvement in the overall mechanical properties of the material.
[0050] Figure 4 These are the heat flow curves of the flexible functional composite materials prepared in Examples 1-5 of this invention.
[0051] like Figure 4 As shown, the heat flux density curves for all embodiments are shown. Each curve shows a significant absorption peak near 37°C, indicating that MPCM undergoes a phase change and absorbs heat at this point. As the MPCM content increases, the peak value of the curve increases, indicating that the heat absorption capacity of the flexible functional composite material is enhanced.
[0052] Figure 5 This is a schematic diagram of the latent heat of the flexible functional composite materials prepared in Examples 1-5 of the present invention.
[0053] like Figure 5 The figure shows the latent heat values for all embodiments. As can be seen from the figure, the latent heats of Embodiment 1, Embodiment 2, Embodiment 3, Embodiment 4, and Embodiment 5 are 82.5 J / g, 72.4 J / g, 63.3 J / g, 51.3 J / g, and 38.1 J / g, respectively. This indicates that the thermal buffering capacity of the material increases with the increase of MPCM content.
[0054] Figure 6 This is a schematic diagram of the overall thermal conductivity of the flexible functional composite materials prepared in Examples 1-5 of the present invention.
[0055] like Figure 6 The figure shows the overall thermal conductivity of all embodiments. As can be seen from the figure, the overall thermal conductivity of pure PDMS, Embodiment 1, Embodiment 2, Embodiment 3, Embodiment 4, and Embodiment 5 are 0.185 W / (m·K), 0.248 W / (m·K), 0.349 W / (m·K), 0.484 W / (m·K), 0.672 W / (m·K), and 0.886 W / (m·K), respectively. With the increase of h-BN content, the overall heat dissipation performance of the material is enhanced.
[0056] The high-concentration functional composite material prepared by this invention based on the cross-linking inhibition mechanism and external force constraint has excellent mechanical properties; the use of microcapsule phase change material as the heat-absorbing material can effectively inhibit the leakage of phase change material; at the same time, it exhibits excellent thermal management performance under the synergistic effect of thermally conductive phase and thermal storage phase.
[0057] Those skilled in the art should understand that this invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to this invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.
Claims
1. A method for preparing a flexible functional composite material with excellent thermal management capabilities, characterized in that, The preparation based on crosslinking inhibition mechanism and external force constraint includes the following steps: S1, PDMS prepolymer and crosslinking agent are mixed at a mass ratio of (9~11):1 and stirred thoroughly to obtain a PDMS solution. MPCM powder and h-BN powder are mixed at a certain ratio and stirred thoroughly to obtain a powder mixture. The mass fraction of the MPCM powder is 25-50%wt. The MPCM powder uses melamine-formaldehyde resin as the shell material and n-eicosane as the core material. The average particle size of the MPCM powder is 20~30μm and its phase transition temperature is 37℃. The mass fraction of the h-BN powder is not greater than 25%wt. The average particle size of the h-BN powder is 20~30μm. S2, the powder mixture is added to the PDMS solution to obtain a first mixture, then n-hexane is added and magnetically stirred to obtain a second mixture; S3, after the second mixture is allowed to stand for 10-20 minutes, it is degassed under vacuum to obtain the third mixture; S4, slowly pour the third mixture into the mold, and use external force to vibrate and level the third mixture to fill the mold completely; S5, the mold is placed in an oven for gradient heating to obtain a flexible functional composite material with excellent mechanical properties and thermal management properties. The gradient heating includes a first stage, a second stage, and a third stage. The heating temperature in the first stage is 40-50℃ and the heating time is 2-4 hours; the heating temperature in the second stage is 80-90℃ and the heating time is 1-3 hours; the heating temperature in the third stage is 110-120℃ and the heating time is 0.5-1.5 hours.
2. The method for preparing the flexible functional composite material with excellent thermal management capability according to claim 1, characterized in that: in, The mass ratio of the MPCM powder to the h-BN powder is 7:1, 3:1, 5:3, or 1:
1.
3. The method for preparing the flexible functional composite material with excellent thermal management capability according to claim 1, characterized in that: in, In step S2, the magnetic stirring speed is 1800-2200 rpm, and the time is 0.5-1.5 h.
4. The method for preparing the flexible functional composite material with excellent thermal management capability according to claim 1, characterized in that: in, In step S3, the vacuum degassing time is 25-35 minutes.
5. The method for preparing the flexible functional composite material with excellent thermal management capability according to claim 1, characterized in that: in, In step S4, the thickness of the mold is 0.5mm-1.5mm.
6. A flexible functional composite material with excellent thermal management capabilities, characterized in that, The flexible functional composite material with excellent thermal management capability is prepared according to any one of claims 1 to 5.
7. The flexible functional composite material with excellent thermal management capability according to claim 6, characterized in that, It includes the following components: MPCM thermal storage material with PDMS matrix material, h-BN thermal conductive material, melamine-formaldehyde resin as shell material and n-eicosane as core material.