Preparation method and application of bionic structure temperature adjusting foam

Abstract

The invention discloses a preparation method and application of bionic structure temperature adjusting foam, and belongs to the technical field of functional material and phase change energy storage crossing. According to the method, melamine foam serves as a matrix, phenolic resin is used for filling part of pores of foam, polyethylene glycol is adsorbed in vacuum for modification, and the formed temperature-adjusting foam has the characteristics of high enthalpy value and leakage prevention and has the functions of temperature adjustment, photo-thermal conversion, flame retardance and the like. The method is high in operability, simple in equipment, short in process and energy-saving, all component materials can be fully utilized, and waste is avoided; the obtained temperature-adjusting foam does not leak the phase-change material in a general state and can be recycled for multiple times; and the melting enthalpy and the crystallization enthalpy are relatively large, and an excellent temperature adjusting effect can be realized.

Description

Technical Field

[0001] This invention relates to the field of functional materials and phase change energy storage, specifically to a method for preparing and applying a biomimetic temperature-regulating foam, applicable to waste heat recovery and utilization, intelligent temperature regulation of textiles, building energy conservation, and other fields. Background Technology

[0002] Three-dimensional porous foam is a solid material with a three-dimensional network structure. Its skeleton provides strength and support, while its numerous interconnected pores provide containment space and flow channels. Due to its vast functional space, efficient transport channels, and robust skeleton support, it has attracted much attention, providing a platform for the design and manufacture of high-performance, multifunctional, and even intelligent advanced materials.

[0003] With the continued advancement of global industrialization and the expansion of the population, energy demand continues to rise, leading to increasingly prominent energy supply pressures and environmental pollution problems. To achieve a green transformation of the energy system and a balance between supply and demand for sustainable development, promoting the large-scale application of efficient and reliable energy storage technologies has become an indispensable part. Thermal energy storage technology collects and stores temporarily surplus or waste heat (such as industrial waste heat and excess solar energy), releasing and utilizing the stored heat when needed, thereby effectively improving overall energy utilization efficiency. Among these technologies, phase change energy storage technology has attracted widespread attention due to the high energy density of phase change materials (PCMs) and the relatively stable temperature during the phase change process.

[0004] Solid-liquid PCMs, as excellent latent heat energy storage materials, possess advantages such as high energy storage efficiency, small volume change during energy storage and release, high latent heat of phase change, and stable chemical structure. They are also diverse in type, widely available, and inexpensive, making them widely used in solar thermal storage systems, industrial waste heat utilization, building energy conservation, and the textile industry. However, solid-liquid PCMs have drawbacks such as easy leakage and flammability, which limit their wider application and development.

[0005] Three-dimensional porous foams can effectively encapsulate phase change components within a porous network through physical adsorption, capillary forces, interfacial interactions, and spatial confinement effects, thereby achieving a morphologically stable thermal energy storage and release process. Based on the composition and structural type of the framework, current porous framework-based phase change materials mainly include porous foams, polymer aerogels, inorganic aerogels, and organic / inorganic composite aerogels. Melamine foam (MF) is characterized by its lightweight, low density, and high porosity, while also possessing good thermal insulation, flame retardancy, chemical stability, and mechanical resilience, making it widely used in construction, automotive, and thermal management. In recent years, researchers have utilized melamine foam as a physical support framework, effectively confining solid-liquid phase change materials within its pores through capillary action and interfacial interactions, thus effectively suppressing liquid leakage during the phase change process. However, the excessively large pore size of melamine foam can lead to localized enrichment of the phase change material, increasing the risk of leakage.

[0006] To further address the encapsulation issues of phase change materials (PCMs), current methods primarily include surface coating technology and the construction of multi-level structures. Surface coating technology involves creating a dense "protective film" on the outermost layer of the foam composite material, physically preventing the leakage of liquid PCMs. This method is simple to implement and relatively inexpensive, but it carries the risk of damage. Micro-cracks or pinholes in the coating can become leakage channels, and since the coating itself does not participate in the phase change, it reduces the overall heat storage density of the material. Combining foam and resin has recently become a hot topic in solving the leakage problem of PCMs. Constructing multi-level structures increases the surface roughness and pore complexity of the framework, enhancing capillary forces and interfacial interactions to adsorb liquid PCMs, which has a positive impact on thermal performance. However, the process is complex and costly. Summary of the Invention

[0007] Technical issues Solid-liquid phase change materials are prone to leakage and are flammable, limiting their widespread application. Although melamine foam can encapsulate phase change materials through capillary action as a support framework, its large pore size can lead to local enrichment of phase change materials, increasing the risk of leakage. Existing surface coating technologies have the potential for damage and leakage and reduce heat storage density. Constructing multi-level structures is complex and costly, and none of these technologies can efficiently solve the encapsulation and leakage problems of phase change materials.

[0008] Technical content To address the shortcomings of existing technologies, this invention develops a scientifically sound, practical, and highly operable method for preparing multifunctional temperature-regulating foam. The aim is to simplify the material production process, improve production efficiency, and optimize the material's thermal storage performance. This invention uses a three-dimensional porous foam as the matrix, which is modified with resin and phase change materials to endow the material with temperature-regulating capabilities. This method is simple to operate, has low preparation costs, and can improve the thermal performance of phase change materials. Inspired by succulent fruits such as tomatoes, kiwis, loofahs, and eggplants, this invention uses melamine foam modified with phenolic resin as the framework, obtaining the target material through vacuum adsorption of polyethylene glycol. The melamine foam acts like the central axis and vascular bundles of the fruit, providing skeletal support; the cured phenolic resin acts like the pulp, enhancing the matrix strength while providing more binding sites, thus better encapsulating the phase change material as a "gel." This design utilizes the chemical curing of phenolic resin to construct an enhanced network with abundant interfacial binding sites. Through synergistic capillary action and physical adsorption, it significantly improves the mechanical strength of the framework while achieving high loading capacity and excellent shape stability in phase change materials. The preparation process of this temperature-regulating foam is simple, maintaining not only a high phase change enthalpy and cyclic thermal stability, but also, thanks to the intrinsic properties of the framework, simultaneously integrating high photothermal conversion and flame-retardant properties. This solves the problem of the single function of conventional melamine foam matrices and provides a new strategy for developing integrated, multifunctional foams for various applications such as waste heat recovery and high-temperature protection.

[0009] Based on the heat storage mechanism of phase change materials, the higher the phase change component in the composite material, the greater the stored energy. This invention, while overcoming the leakage problem of solid-liquid phase change materials, provides a highly efficient and high-quality multifunctional temperature-regulating foam preparation method. This temperature-regulating foam can stably store phase change materials and has excellent temperature regulation performance, making it suitable for waste heat recovery and utilization, intelligent temperature regulation of textiles, and building energy conservation.

[0010] The first objective of this invention is to provide a method for preparing temperature-regulating foam, the method comprising the following steps: (1) Preparation of resin solution: Dissolve the resin in ethanol and stir evenly to obtain a resin solution; (2) Preparation of composite foam skeleton: clean and dry the foam, then place the treated foam in the resin solution, squeeze and impregnate, and then cure and dry to obtain composite foam skeleton; (3) Preparation of temperature-regulating foam: The composite foam prepared in step (2) is immersed in molten phase change material, vacuum adsorption is performed, and then excess phase change material on the surface of the material is removed to finally obtain temperature-regulating foam.

[0011] In one embodiment of the present invention, the resin mentioned in step (1) is selected from any one or more of the following: phenolic resin, phthalic acid nitrile resin, polyurethane, epoxy resin, and urea-formaldehyde resin.

[0012] Preferably, the resin mentioned in step (1) is selected from phenolic resin, epoxy resin or urea-formaldehyde resin.

[0013] In one embodiment of the present invention, the ethanol mentioned in step (1) is anhydrous ethanol or an ethanol solution with a water content of less than 10 wt%.

[0014] In one embodiment of the present invention, the ethanol mentioned in step (1) can be replaced with methanol, n-propanol, isopropanol, butanol, acetone or benzyl alcohol.

[0015] In one embodiment of the present invention, the concentration of resin in the resin solution in step (1) is 1~20wt%.

[0016] In one embodiment of the present invention, the resin concentration in the resin solution in step (1) is 3~10wt%.

[0017] In one embodiment of the present invention, the stirring speed in step (1) is 800~1000 rpm and the time is 20-30 min.

[0018] In one embodiment of the present invention, the foam described in step (2) is selected from any one or more of the following: melamine foam, polyurethane foam, porous carbon foam, nickel foam, copper foam, and boron nitride foam.

[0019] In one embodiment of the present invention, the volume of the foam in step (2) is not limited; the density of the foam is 0.001-5.000 g / cm³. 3 .

[0020] In one embodiment of the present invention, a curing agent needs to be added to the resin solution in step (2); the curing agent is determined according to the type of resin, such as aliphatic amines, polyamides, etc. can be selected as curing agents for epoxy resin; acids can be selected as curing agents for phenolic resin; ammonium salts, acids, etc. can be selected as curing agents for urea-formaldehyde resin.

[0021] Specifically, when the resin is a phenolic resin, the curing agent may be sulfuric acid, p-toluenesulfonic acid, or phosphoric acid.

[0022] Specifically, when the resin is epoxy resin, the curing agent may be diethylenetriamine, triethylenetetramine, or m-phenylenediamine.

[0023] Specifically, when the resin is urea-formaldehyde resin, the curing agent may be ammonium chloride, ammonium sulfate, oxalic acid, acetic acid, or hydrochloric acid.

[0024] In one embodiment of the present invention, the mass ratio of resin to curing agent is 3-20:1.

[0025] In one embodiment of the present invention, the mass ratio of resin to curing agent is 10-20:1.

[0026] In one embodiment of the present invention, the mass ratio of resin to curing agent is 10-15:1.

[0027] In one embodiment of the present invention, the number of times of squeezing and impregnation in step (2) is 5-50 times.

[0028] In one embodiment of the present invention, the curing and drying temperature in step (2) is 60-100 °C.

[0029] In one embodiment of the present invention, the curing and drying time in step (2) is 1-5 h.

[0030] In one embodiment of the present invention, the phase change material described in step (3) is selected from any one or more of the following: inorganic: crystalline hydrated salts (calcium chloride hexahydrate, sodium sulfate decahydrate, disodium hydrogen phosphate dodecahydrate, etc.), molten salts (nitrates, chlorides, etc.), metals and alloys (low melting point metals, aluminum-based alloys, etc.); organic: paraffins (alkanes), fatty acids (decanoic acid, lauric acid, palmitic acid, stearic acid, etc.), polyols (such as pentaerythritol, neopentyl glycol, etc.), polyethylene glycol, etc.; eutectic: organic-organic, inorganic-inorganic, organic-inorganic mixed systems.

[0031] Specifically, the phase change material may be selected from polyethylene glycol (PEG1000, PEG2000), lauric acid, or stearic acid.

[0032] In one embodiment of the present invention, the temperature of the molten phase change material in step (3) is 60-100°C.

[0033] In one embodiment of the present invention, the immersion time in step (3) is 2 to 6 hours.

[0034] In one embodiment of the present invention, the vacuum degree of vacuum adsorption in step (3) is -0.4 to -0.8 bar.

[0035] The second objective of this invention is to provide a temperature-regulating foam with a biomimetic structure using the above-described preparation method.

[0036] A third objective of this invention is to apply the aforementioned temperature-regulating foam in textiles and construction.

[0037] Beneficial effects 1. This invention uses phenolic resin and polyethylene glycol to modify melamine foam. Phenolic resin, after curing, exhibits excellent high-temperature resistance and mechanical properties, and its synthesis involves simple raw materials, low cost, and a simple production process. The combination of melamine foam and resin improves the mechanical properties of the foam and increases the number of bonding sites, facilitating the subsequent addition of phase change materials. Furthermore, the resin bridges the foam skeleton nodes, reducing interfacial thermal resistance and increasing the material's thermal conductivity; the conjugated structure formed by the cured phenolic resin broadens the light absorption spectrum, improving the material's photothermal conversion efficiency; and it can also synergistically enhance the flame retardancy of melamine foam, significantly reducing the flammability of temperature-regulating foam. The combination of melamine foam and phenolic resin, along with the adsorption of phase change materials, produces a temperature-regulating foam with multiple functions, including high enthalpy, leak-proof properties, stable thermal cycling, and flame retardancy.

[0038] 2. The method of this invention is highly operable, uses simple equipment, has a short process, and is energy-saving, achieving full utilization of each component material without waste. The resulting temperature-regulating foam does not leak phase change material under normal conditions and can be recycled multiple times; it has a large melting enthalpy and crystallization enthalpy, enabling excellent temperature regulation effects. Attached Figure Description

[0039] Figure 1 A schematic diagram of the biomimetic structure and process of temperature-regulating foam; Figure 2 This is a scanning electron microscope image of the foam skeleton prepared in Example 1; Figure 3 This is a scanning electron microscope image of the temperature-controlled foam prepared in Example 1. Figure 4 Phase change energy storage curves of the temperature-controlled foams prepared in Examples 1-3; Figure 5 Leakage images of the temperature-regulating foams prepared in Examples 1-3; Figure 6 The mechanical properties of the foam skeleton prepared in Example 1; Figure 7 The flame retardant properties of the temperature-regulating foam prepared in Example 1; Figure 8 The thermal cycling stability of the temperature-controlled foam prepared in Example 1. Detailed Implementation

[0040] Source of raw materials Melamine foam was purchased from Sichuan Chaoju New Material Technology Co., Ltd., measuring 3.5 × 3 × 1 cm. 3 The mass is 0.09±0.01 g under the specified conditions.

[0041] Example 1 Preparation of biomimetic temperature-regulating foam: (1) Preparation of resin solution: Weigh 0.7 g of phenolic resin (PR) and 9.3 g of anhydrous ethanol (EtOH), place them in a 50 mL beaker and dissolve them at 25 °C. Stir at 800 rpm for 30 min to form a clear and uniform resin solution.

[0042] (2) Cut the melamine foam (MF) into a certain size (3.5×3×1 cm). 3 The resin was ultrasonically cleaned in ethanol for 30 min, then repeatedly rinsed with deionized water, and finally dried in an oven at 80 °C for 2 h. 0.14 g of 40% H₂SO₄ was added to the prepared resin solution as a curing agent, and the mixture was magnetically stirred for 30 min. MF was then immersed in the prepared solution, repeatedly squeezed and impregnated, and finally dried and cured in an oven at 80 °C for 3 h. This sample was designated MF / PR-7.

[0043] (3) MF / PR-7 was placed in an 80 ℃ vacuum oven (-0.6 bar) to adsorb PEG2000 for 4 h. After adsorption was complete, it was removed and dried on neutral filter paper, and then placed in the 80 ℃ oven again to remove excess PEG from the sample surface. During this process, the filter paper was changed continuously until the sample no longer leaked PEG. The sample was named PEG / MF / PR-7.

[0044] The process of preparing the temperature-regulating foam in the above steps is as follows: Figure 1 As shown. Scanning electron microscope (SEM) images of the foam skeleton and temperature-controlled foam obtained in steps (2) and (3) are shown below. Figure 2 , Figure 3 As shown. The mechanical properties of the foam skeleton obtained in step (2) are as follows. Figure 6 As shown.

[0045] from Figure 2 , 3 It can be seen that after impregnation with phenolic resin, the MF skeleton is gradually filled and covered by the resin, the fiber veins thicken, and spherical particles or irregular sheet-like fillings appear at the skeleton joints, exhibiting open-pore and closed-pore structures. After vacuum adsorption of PEG, the pores of MF / PR-7 are filled, resulting in a rough surface that increases the contact area between PEG and heat, thus improving the material's heat transfer efficiency. Figure 6 It can be seen that the mechanical strength of MF / PR-7 is improved due to the modification of phenolic resin.

[0046] Differential thermal scanning was performed on the above-mentioned temperature-regulating foam. Figure 4 ),leakage( Figure 5Analysis of the PEG / MF / PR-7 sample and its thermal conductivity (Table 1) showed that the melting temperature was 56.6 °C, the enthalpy of melting was 159.2 J / g, the crystallization temperature was 34.2 °C, and the enthalpy of crystallization was 154.9 J / g. A leak test was conducted on a 60 °C heating platform, and no leaks were found in the PEG / MF / PR-7 sample. The thermal conductivity was 0.1789 W·m. -1 ·K -1 .

[0047] Table 1

[0048] Example 2 Preparation of biomimetic temperature-regulating foam: (1) Preparation of resin solution: Weigh 0.5 g of phenolic resin (PR) and 9.5 g of anhydrous ethanol (EtOH), place them in a 50 mL beaker, dissolve them at 25 °C, and stir at 800 rpm for 30 min to form a clear and uniform resin solution.

[0049] (2) Cut the melamine foam (MF) into a certain size (3.5×3×1 cm). 3 The resin was ultrasonically cleaned in ethanol for 30 min, then repeatedly rinsed with deionized water, and finally dried in an oven at 80 ℃ for 2 h. 0.1 g of 40% H2SO4 was added to the prepared resin solution as a curing agent, and the mixture was magnetically stirred for 30 min. MF was then immersed in the prepared solution, repeatedly squeezed and impregnated, and finally dried and cured in an oven at 80 ℃ for 3 h. This sample is designated MF / PR-5.

[0050] (3) MF / PR-5 was placed in an 80 ℃ vacuum oven (-0.6 bar) to adsorb PEG2000 for 4 h. After adsorption was complete, it was removed and dried on neutral filter paper, and then placed in the 80 ℃ oven again to remove excess PEG from the sample surface. During this process, the filter paper was changed continuously until the sample no longer leaked PEG. The sample was named PEG / MF / PR-5.

[0051] Differential thermal scanning and leakage analysis were performed on the above-mentioned temperature regulation. The melting temperature of the prepared foam was 58.0 °C, the enthalpy of melting was 150.5 J / g, the crystallization temperature was 34.8 °C, and the enthalpy of crystallization was 142.4 J / g. Leakage tests were conducted on a 60 °C heating stage, and no leakage was found in the phase change composite material.

[0052] Example 3 Preparation of biomimetic temperature-regulating foam: (1) Preparation of resin solution: Weigh 0.3 g of phenolic resin (PR) and 9.7 g of anhydrous ethanol (EtOH), place them in a 50 mL beaker, dissolve them at 25 °C, and stir at 800 rpm for 30 min to form a clear and uniform resin solution.

[0053] (2) Cut the melamine foam (MF) into a certain size (3.5×3×1 cm). 3 The resin was ultrasonically cleaned in ethanol for 30 min, then repeatedly rinsed with deionized water, and finally dried in an oven at 80 ℃ for 2 h. 0.06 g of 40% H2SO4 was added to the prepared resin solution as a curing agent, and the mixture was magnetically stirred for 30 min. MF was then immersed in the prepared solution, repeatedly squeezed and impregnated, and finally dried and cured in an oven at 80 ℃ for 3 h. This sample is designated MF / PR-3.

[0054] (3) MF / PR-3 was placed in an 80 ℃ vacuum oven (-0.6 bar) to adsorb PEG2000 for 4 h. After adsorption was complete, it was removed and dried on neutral filter paper, and then placed in the 80 ℃ oven again to remove excess PEG from the sample surface. During this process, the filter paper was changed continuously until the sample no longer leaked PEG. The sample was named PEG / MF / PR-3.

[0055] Differential thermal scanning and leakage analysis were performed on the above-mentioned temperature-regulating foam. The melting temperature of the prepared foam was 56.3 °C, the melting enthalpy was 144.8 J / g, the crystallization temperature was 33.4 °C, and the crystallization enthalpy was 141.6 J / g. Leakage tests were conducted on a 60 °C heating platform and it was found that the temperature-regulating foam did not leak.

[0056] Comparative Example 1 Preparation of biomimetic temperature-regulating foam: (1) Cut the melamine foam (MF) into a certain size (3.5×3×1 cm). 3 The sample was ultrasonically cleaned in ethanol for 30 minutes, then repeatedly cleaned with deionized water, and finally dried in an oven at 80 ℃ for 2 hours.

[0057] (2) MF was placed in an 80 ℃ vacuum oven (-0.6 bar) to adsorb PEG2000 for 4 h. After adsorption was complete, it was removed and dried on neutral filter paper, and then placed in the 80 ℃ oven again to remove excess PEG from the sample surface. During this process, the filter paper was changed continuously until the sample no longer leaked PEG. The sample was recorded as PEG / MF.

[0058] Analysis of PEG adsorption and leakage of the above-mentioned temperature-controlled foam showed that the amount of PEG adsorbed by the prepared temperature-controlled foam was significantly less than that of the PEG / MF / PR temperature-controlled foam; and leakage tests conducted on a 60 ℃ heating stage revealed that PEG flowed out of this temperature-controlled foam.

[0059] Comparative Example 2 Preparation of biomimetic temperature-regulating foam: (1) Preparation of resin solution: Weigh 0.7 g of phenolic resin (PR) and 9.3 g of anhydrous ethanol (EtOH), place them in a 50 mL beaker, dissolve them at 25 °C, and stir at 800 rpm for 30 min to form a clear and uniform resin solution.

[0060] (2) Cut the melamine foam (MF) into a certain size (3.5×3×1 cm). 3 The sample was ultrasonically cleaned in ethanol for 30 minutes, then repeatedly rinsed with deionized water, and then dried in an oven at 80 ℃ for 2 hours. MF was then immersed in the prepared solution, repeatedly squeezed and impregnated, and then dried and cured in an oven at 80 ℃ for 3 hours.

[0061] (3) MF / PR was placed in an 80 ℃ vacuum oven (-0.6 bar) to adsorb PEG2000 for 4 h. After adsorption was complete, it was removed and dried on neutral filter paper, and then placed in the 80 ℃ oven again to remove excess PEG from the sample surface. During this process, the filter paper was changed continuously until the sample no longer leaked PEG. A small amount of yellow substance flowed out with PEG during this process. This was because no resin curing agent was added, so some resin only temporarily adhered to MF and did not cure. The resin would flow out during reheating.

[0062] Comparative Example 3 Preparation of biomimetic temperature-regulating foam: (1) Preparation of resin solution: Weigh 0.7 g of phenolic resin (PR) and 9.3 g of anhydrous ethanol (EtOH), place them in a 50 mL beaker, dissolve them at 25 °C, and stir at 800 rpm for 10 min to form a clear and uniform resin solution.

[0063] (2) Cut the melamine foam (MF) into a certain size (3.5×3×1 cm). 3 The resin was ultrasonically cleaned in ethanol for 30 min, then repeatedly cleaned with deionized water, and then dried in an oven at 80 ℃ for 2 h. 0.14 g of 40% H2SO4 was added to the prepared resin solution as a curing agent, and the mixture was magnetically stirred for 10 min. MF was then immersed in the prepared solution, repeatedly squeezed and impregnated, and finally dried and cured in an oven at 80 ℃ for 3 h.

[0064] (3) MF / PR was placed in an 80 ℃ vacuum oven (-0.6 bar) to adsorb PEG2000 for 4 h. After adsorption was complete, it was removed and dried on neutral filter paper, and then placed in the 80 ℃ oven again to remove excess PEG from the sample surface. During this process, the filter paper was changed continuously until the sample no longer leaked PEG.

[0065] Surface morphology analysis of the above-mentioned temperature-controlled foam revealed that the resin cured on the melamine foam skeleton agglomerated. This was because the stirring time of the resin solution was too short, and the phenolic resin was not evenly dispersed in anhydrous ethanol, which caused the resin loaded onto the foam to agglomerate, resulting in a noticeable granular texture, which is not conducive to the subsequent encapsulation of phase change materials.

[0066] Comparative Example 4 Preparation of the foam skeleton: Melamine foam (MF) is cut into a certain size (3.5×3×1 cm). 3 The phenolic resin was ultrasonically cleaned in ethanol for 30 min, then repeatedly rinsed with deionized water, and then dried in an oven at 80 ℃ for 2 h. 0.7 g of phenolic resin was mixed with 0.14 g of 40% H2SO4 and stirred at 200 rpm for 10 min. The MF was then immersed in the mixture, repeatedly squeezed and impregnated, and then dried and cured in an oven at 80 ℃ for 3 h.

[0067] During the preparation process, it was found that the high viscosity of phenolic resin led to uneven impregnation of the melamine foam, resulting in areas with excessive or absent resin, primarily concentrated on the foam surface. Therefore, the foam skeleton preparation method in Examples 1-3 is the optimal solution.

[0068] The above are merely specific application examples of the present invention and do not constitute any limitation on the scope of protection of the present invention. All technical solutions formed by equivalent transformations or equivalent substitutions fall within the scope of protection of the present invention.

Claims

1. A method for preparing temperature-regulating foam, characterized in that, The method includes the following steps: (1) Preparation of resin solution: Dissolve the resin in ethanol and stir evenly to obtain a resin solution; (2) Preparation of composite foam skeleton: clean and dry the foam, add curing agent to the resin solution obtained in step (1), then place the dried foam in the resin solution, squeeze and impregnate, and then cure and dry to obtain composite foam skeleton; (3) Preparation of temperature-regulating foam: The composite foam prepared in step (2) is impregnated in molten phase change material, vacuum adsorption is performed, and then excess phase change material on the surface of the material is removed to finally obtain temperature-regulating foam. The resin mentioned in step (1) is selected from any one or more of the following: phenolic resin, epoxy resin or urea-formaldehyde resin; The foam mentioned in step (2) is selected from any one or more of the following: melamine foam, polyurethane foam, porous carbon foam, nickel foam, copper foam, and boron nitride foam; In step (2), when the resin is phenolic resin, the curing agent is sulfuric acid, p-toluenesulfonic acid or phosphoric acid; when the resin is epoxy resin, the curing agent is diethylenetriamine, triethylenetetramine or m-phenylenediamine; when the resin is urea-formaldehyde resin, the curing agent is ammonium chloride, ammonium sulfate, oxalic acid, acetic acid or hydrochloric acid.

2. The preparation method according to claim 1, characterized in that, The resin concentration in the resin solution described in step (1) is 1~20 wt%.

3. The preparation method according to claim 1, characterized in that, The stirring speed in step (1) is 800~1000 rpm and the time is 20-30 min.

4. The preparation method according to claim 1, characterized in that, In step (2), the mass ratio of resin to curing agent is 3-20:

1.

5. The preparation method according to claim 1, characterized in that, The number of extrusion impregnation cycles in step (2) is 5-50; the curing and drying temperature is 60-100 ℃, and the time is 1-5 h.

6. The preparation method according to claim 1, characterized in that, The phase change material mentioned in step (3) is selected from one or more of inorganic, organic, or eutectic types; the inorganic type includes hydrated salts, molten salts, metals and / or alloys; the hydrated salts include calcium chloride hexahydrate, sodium sulfate decahydrate, and disodium hydrogen phosphate dodecahydrate; the molten salts include nitrates and chlorides; the organic type includes paraffins, fatty acids, polyols, and polyethylene glycols; the fatty acids include decanoic acid, lauric acid, palmitic acid, and stearic acid; the polyols include pentaerythritol and neopentyl glycol.

7. The preparation method according to claim 6, characterized in that, The phase change material is selected from polyethylene glycol, lauric acid, or stearic acid.

8. The preparation method according to claim 1, characterized in that, The temperature of the molten phase change material in step (3) is 60-100 ℃.

9. The preparation method according to claim 1, characterized in that, The immersion time in step (3) is 2 to 6 hours; the vacuum degree of vacuum adsorption is -0.4 to -0.8 bar.

10. A temperature-regulating foam with a biomimetic structure, characterized in that, The temperature-regulating foam is prepared according to any one of claims 1 to 9.

Images