Flexible shape-stabilized phase change film and preparation method thereof

Abstract

The invention discloses a flexible shape-stabilized phase change film which comprises the following components in parts by mass: 50-90 parts of a phase change material; 10 parts of silicon oxide aerogel; 30 to 100 parts of flexible silicon resin; the phase change material is an alkane phase change material containing methyl or ethyl. The invention also discloses a preparation method of the film. The preparation method comprises the following steps: heating the alkane phase-change material in a drying oven until the alkane phase-change material is completely molten into a liquid state; the preparation method comprises the following steps: uniformly mixing a liquid alkane phase change material with silicon oxide aerogel, and naturally cooling to form a shape-stabilized phase change block; crushing the shape-stabilized phase change block to obtain shape-stabilized phase change powder; mixing the shape-stabilized phase change powder and flexible methyl silicone resin, putting the mixture into a mold, and pressing to obtain a phase change film blank; and curing the phase change film blank at room temperature, and demolding to form the flexible shape-stabilized phase change film. The flexible shape-stabilized phase change film is high in phase change enthalpy value and stable in structure after phase change and can be conveniently pasted and fixed to the surface of an arc-shaped structure such as an aircraft bulkhead and the special-shaped surface of instrument equipment, and efficient long-time phase change thermal control over the cabin structure and the special-shaped surface of the instrument equipment is achieved.

Description

Technical Field

[0001] This invention relates to a phase change film, specifically a flexible shaped phase change film and its preparation method, belonging to the field of functional composite material manufacturing technology. Background Technology

[0002] Phase change materials (PCMs) are widely used in the temperature control of internal structures and instruments in aircraft, offering advantages such as high heat storage density, good stability, and high reliability. Solid-liquid PCMs are diverse, with a wide phase change temperature range and high enthalpy, making them the most widely used PCMs in phase change thermal control. However, solid-liquid PCMs require encapsulation to ensure no leakage after liquefaction. Flexible encapsulation allows PCMs to be applied to curved and irregularly shaped surfaces for phase change thermal control, significantly expanding their application range. Currently, the shaping and encapsulation methods for flexible PCMs mainly include polymer coating, porous adsorption, and chemical cross-linking. While ensuring no leakage during solid-liquid phase change, insufficient encapsulation capacity leads to insufficient PCM content, resulting in a low average enthalpy of the flexible PCM composite material. A low enthalpy shortens the phase change thermal control time; achieving the target thermal control time requires increasing the amount of PCM, increasing weight and occupying more usable cabin space.

[0003] Therefore, how to solve the shortcomings of flexible shaped phase change materials through dual-mechanism synergistic shaping optimization and provide a high-enthalpy flexible shaped phase change film is the key technical issue for its further expansion of application. Summary of the Invention

[0004] The purpose of this invention is to overcome the aforementioned defects and provide a flexible, shape-stabilized phase change film and its preparation method, solving the technical problem of low average phase change enthalpy value in current flexible phase change composite materials. The flexible, shape-stabilized phase change film of this invention has a high phase change enthalpy value and a stable structure after phase change, making it easy to adhere and fix to curved surfaces such as aircraft cabin walls and irregularly shaped surfaces of instruments and equipment, achieving efficient and long-term phase change thermal control of cabin structures and irregularly shaped surfaces of instruments and equipment.

[0005] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0006] A flexible, shape-stabilized phase change film comprises the following components in parts by weight:

[0007] 50-90 parts of phase change material;

[0008] 10 parts of silica aerogel;

[0009] 30-100 parts of flexible silicone resin;

[0010] Phase change materials are alkane-based phase change materials containing methyl or ethyl groups.

[0011] Furthermore, the phase change material includes one or more of octadecane to tetradecane.

[0012] Furthermore, the silica aerogel is a silica aerogel that has undergone hydrophobic treatment;

[0013] The porous surface of silica aerogel contains methyl or ethyl groups;

[0014] The specific surface area of ​​silica aerogel is 600–1200 g / m².

[0015] Furthermore, flexible silicone resins include flexible methyl silicone resins that can be cured at room temperature.

[0016] Furthermore, the flexible silicone resin is an addition-type 102-methyl silicone resin.

[0017] The above-mentioned method for preparing a flexible shaped phase change film includes:

[0018] The alkane-based phase change material is heated in an oven until it is completely melted into a liquid state;

[0019] Liquid alkane phase change materials are mixed evenly with silica aerogel and then naturally cooled to form a shaped phase change bulk.

[0020] The shaped phase change bulk material is crushed to obtain the shaped phase change powder.

[0021] The shaped phase change powder is mixed with flexible methyl silicone resin and placed in a mold, and then pressed to obtain a phase change film blank.

[0022] After the phase change film preform is cured at room temperature, it is demolded to form a flexible, shaped phase change film.

[0023] Furthermore, the shaped phase change powder has a particle size of 10–1000 μm;

[0024] When the phase change film preform is cured at room temperature, the curing time is 24 to 48 hours.

[0025] Furthermore, liquid alkane phase change materials are mixed with silica aerogel at a mass ratio of 5:1 to 9:1;

[0026] Let the specific surface area of ​​silica aerogel be S:

[0027] When 600g / ㎡≤S<700g / ㎡, the mass ratio of liquid alkane phase change material to silica aerogel is 5:1;

[0028] When 700g / ㎡≤S<800g / ㎡, the mass ratio of liquid alkane phase change material to silica aerogel is 6:1;

[0029] When 800g / ㎡≤S<900g / ㎡, the mass ratio of liquid alkane phase change material to silica aerogel is 7:1;

[0030] When 900g / m²≤S<1000g / m², the mass ratio of liquid alkane phase change material to silica aerogel is 8:1;

[0031] When 1000g / m²≤S<1200g / m², the mass ratio of liquid alkane phase change material to silica aerogel is 9:1.

[0032] Furthermore, the mass ratio of the shaped phase change powder to the flexible methyl silicone resin is 1:1 to 2:1.

[0033] This invention discloses a flexible shaped phase change film and its preparation method. The phase change film uses an alkane phase change material shaped by hydrophobic silica aerogel as the phase change filler and flexible methyl silicone resin as the matrix phase. The phase change thermophysical properties are adjusted by modifying the content of the phase change material, aerogel, and flexible methyl silicone resin in the phase change film. Using a molding process, the flexible phase change film can be cured at room temperature, with an average density of 950±50 kg / m³. 3 The average phase change enthalpy is 100-150 kJ / kg. This flexible, shaped phase change film has a simple manufacturing process, can be cured at room temperature, and exhibits excellent thermal control performance. It can be used for phase change thermal control of various new types of aircraft cabin walls and instruments. Currently, it has been applied to phase change thermal control of aircraft cabin walls, effectively reducing the internal temperature of the aircraft cabin. Especially when the thickness of the internal insulation layer is limited, phase change thermal control has a better unit space insulation efficiency ratio, ensuring normal operating temperature inside the aircraft. It also has potential for broad applications in the civilian sector.

[0034] Compared with the prior art, the present invention has at least one of the following advantages:

[0035] (1) The present invention uses silica aerogel with functional groups such as methyl and ethyl on the porous surface to shape alkane phase change materials. It not only utilizes the capillary force of the micron and nano-sized pores of the aerogel to adsorb alkane phase change materials, but also further enhances the shaping ability of the aerogel on alkane phase change materials through the intermolecular interaction between the methyl and ethyl functional groups on the aerogel surface and the methyl and ethyl functional groups of the alkane phase change materials, ensuring no leakage after the alkane phase change materials are liquefied.

[0036] (2) This invention introduces a flexible silicone resin similar to addition-type 102-methyl silicone resin. On the one hand, it serves as a flexible matrix material for flexible phase change films; on the other hand, its methyl side chains can also have better intermolecular forces with the alkane phase change materials on the surface of the shaped phase change powder, further enhancing the shaping effect on the alkane phase change materials. Through the above-mentioned dual-mechanism multi-level synergistic shaping effect, it is ensured that there is no leakage or volatilization after the phase change material liquefies within the working temperature range.

[0037] (3) The flexible shaped phase change film of the present invention has a high phase change enthalpy, up to 150 kJ / kg, and an average density of 950 ± 50 kg / m³. 3 This is beneficial for improving the duration of phase change thermal control; the flexible shaped phase change film has a stable structure after phase change, making it easy to stick and fix on the curved surface of aircraft cabin walls and other irregular surfaces of instruments and equipment, so as to achieve efficient and long-term phase change thermal control of cabin structures and irregular surfaces of instruments and equipment. Attached Figure Description

[0038] Figure 1 The images show the SEM morphology and elemental distribution of the flexible shaped phase change film of the present invention, where (a) is the SEM morphology, (b) is the Si element, and (c) is the C element.

[0039] Figure 2 This is a bonding diagram of the flexible shaped phase change film of the present invention on the surface of an arc-shaped structure;

[0040] Figure 3 This is a flowchart of a method for preparing a flexible, shaped phase change film according to the present invention. Detailed Implementation

[0041] The features and advantages of the present invention will become clearer and more explicit from the following detailed description.

[0042] The term “exemplary” as used herein means “serving as an example, embodiment, or illustration.” Any embodiment illustrated herein as “exemplary” is not necessarily to be construed as superior to or better than other embodiments. Although various aspects of embodiments are shown in the accompanying drawings, the drawings are not necessarily drawn to scale unless specifically indicated otherwise.

[0043] This invention provides a flexible, shape-stabilized phase change film. It achieves a dual-mechanism, multi-level synergistic shaping effect primarily through capillary adsorption in the micron- and nano-scale pores of the aerogel, and through intermolecular van der Waals forces between the methyl and ethyl functional groups on the aerogel surface and the methyl and ethyl functional groups in the alkane phase change material, as well as through intermolecular van der Waals forces between the methyl and ethyl functional groups on the surface of the shape-stabilized phase change powder and the methyl groups in the flexible methyl silicone resin. This ensures no leakage and no volatilization after the phase change material undergoes phase change liquefaction. This flexible, shape-stabilized phase change film has a high phase change enthalpy, reaching up to 150 kJ / kg, and an average density of 950 ± 50 kg / m³. 3 This is beneficial for improving the duration of phase change thermal control; the flexible shaped phase change film has a stable structure after phase change, making it easy to stick and fix on the curved surface of aircraft cabin walls and other irregular surfaces of instruments and equipment, so as to achieve efficient and long-term phase change thermal control of cabin structures and irregular surfaces of instruments and equipment.

[0044] Another object of the present invention is to provide a method for preparing a shape-fixed phase change film.

[0045] A flexible shaped phase change film comprises a phase change material, a silica aerogel, and a flexible silicone resin, wherein the phase change material accounts for 50-90 parts, the silica aerogel accounts for 10 parts, and the flexible silicone resin accounts for 30-100 parts.

[0046] Phase change materials include alkane phase change materials containing functional groups such as methyl and ethyl groups, such as octadecane to tetradecane.

[0047] Silica aerogel is a silica aerogel that has undergone hydrophobic treatment. The surface of the aerogel pores contains functional groups such as methyl and ethyl groups, and the specific surface area is 600-1200 g / m². The preferred specific surface area of ​​the hydrophobic treated silica aerogel is 800-1000 g / m². Selecting silica aerogels with functional groups such as methyl and ethyl groups on the pore surface can enable stronger intermolecular forces between them and alkane phase change materials containing functional groups such as methyl and ethyl groups. In this way, the aerogel can better shape alkane phase change materials not only through capillary adsorption but also through enhanced intermolecular forces, ensuring that there is no leakage after the phase change material is liquefied.

[0048] Flexible silicone resins include room-temperature curable flexible methyl silicone resins, such as addition-type 102 methyl silicone resin. Methyl silicone resins also have methyl side chains, which enable them to have stronger intermolecular forces with the methyl and ethyl functional groups on the surface of aerogel-shaped alkane phase change material powders. This enhances the secondary shaping and encapsulation effect of silicone resin on the shaped phase change powder, further ensuring that there is no leakage after the phase change material is liquefied.

[0049] like Figure 3 The preparation method of flexible shaped phase change film is as follows: First, alkane phase change material is heated to 100°C in an oven until it is completely melted into a liquid state. Then, the liquid alkane phase change material is mixed with hydrophobic silica aerogel at a ratio of 5:1 to 9:1 and naturally cooled to form a shaped phase change block. Next, the shaped phase change block is pulverized into shaped phase change powder with a particle size of 10 to 1000 μm using a pulverizer. The shaped phase change powder is mixed with flexible methyl silicone resin at a ratio of 1:1 to 2:1 and then pressed into a phase change film blank in a mold. After curing at room temperature for 24 to 48 hours, it is demolded to form a flexible shaped phase change film.

[0050] Liquid alkane-based phase change materials (PCMs) are mixed with hydrophobic silica aerogel at ratios ranging from 5:1 to 9:1. When the specific surface area of ​​the hydrophobic aerogel is 600-700 g / m², the ratio is 5:1; when the specific surface area is 700-800 g / m², the ratio is 6:1; and when the specific surface area is 800-900 g / m², the ratio is... The ratio of phase change material to hydrophobic silica aerogel is 7:1; when the specific surface area of ​​the hydrophobic aerogel is 900-1000 g / m², the ratio of liquid alkane phase change material to hydrophobic silica aerogel is 8:1; when the specific surface area of ​​the hydrophobic aerogel is 1000-1200 g / m², the ratio of liquid alkane phase change material to hydrophobic silica aerogel is 9:1; wherein the liquid alkane phase change material and hydrophobic silica aerogel are preferably mixed at a ratio of 7:1 to 8:1.

[0051] The shaped phase change powder is mixed with flexible methyl silicone resin at a ratio of 1:1 to 2:1, preferably 1:1 to 1.5:1.

[0052] The average density of the flexible shaped phase change film is 950±50 kg / m³. 3 .

[0053] The average phase transition enthalpy of flexible shaped phase change films is 100-150 kJ / kg.

[0054] Example:

[0055] A flexible, shape-stabilized phase change film comprises the following components in parts by weight.

[0056] Phase change material accounts for 50-90 parts.

[0057] 10 parts silica aerogel

[0058] Flexible silicone resin accounts for 30 to 100 parts.

[0059] In one specific embodiment, the phase change material includes alkane phase change materials containing functional groups such as methyl and ethyl groups, such as octadecane to tetradecane.

[0060] In one specific embodiment, the silica aerogel is a hydrophobic silica aerogel, the aerogel pore surface has functional groups such as methyl and ethyl groups, and the specific surface area is 600-1200 g / m², preferably the specific surface area of ​​the hydrophobic silica aerogel is 800-1000 g / m².

[0061] In one specific embodiment, the flexible silicone resin includes a flexible methyl silicone resin that can be cured at room temperature, such as addition-type 102 methyl silicone resin.

[0062] In one specific embodiment, the flexible shaped phase change film is prepared by first heating an alkane-based phase change material in an oven at 100°C until it is completely melted into a liquid state, then mixing the liquid alkane-based phase change material with hydrophobic silica aerogel at a ratio of 5:1 to 9:1, and allowing it to cool naturally to form a shaped phase change block; then, using a pulverizer, the shaped phase change block is pulverized into shaped phase change powder with a particle size of 10 to 1000 μm; the shaped phase change powder is mixed with flexible methyl silicone resin, and then pressed into a phase change film blank in a mold, cured at room temperature for 24 to 48 hours, and then demolded to form a flexible shaped phase change film.

[0063] In one specific embodiment, liquid alkane-based phase change material and hydrophobic silica aerogel are mixed at a ratio of 5:1 to 9:1. When the specific surface area of ​​the hydrophobic aerogel is 600-700 g / m², the ratio of liquid alkane-based phase change material to hydrophobic silica aerogel is 5:1; when the specific surface area of ​​the hydrophobic aerogel is 700-800 g / m², the ratio is 6:1; and when the specific surface area of ​​the hydrophobic aerogel is 800-900 g / m², the ratio is... The ratio of liquid alkane phase change material to hydrophobic silica aerogel is 7:1; when the specific surface area of ​​the hydrophobic aerogel is 900-1000 g / m², the ratio of liquid alkane phase change material to hydrophobic silica aerogel is 8:1; when the specific surface area of ​​the hydrophobic aerogel is 1000-1200 g / m², the ratio of liquid alkane phase change material to hydrophobic silica aerogel is 9:1; wherein preferably, the liquid alkane phase change material and hydrophobic silica aerogel are mixed at a ratio of 7:1 to 8:1.

[0064] In one specific embodiment, the shaped phase change powder is mixed with flexible methyl silicone resin at a ratio of 1:1 to 2:1, preferably 1:1 to 1.5:1.

[0065] Unless otherwise specified, the experimental methods used in the following examples are conventional methods; the materials and reagents used in the following examples are commercially available unless otherwise specified; the testing methods for the average density and average phase transition enthalpy of the raw materials and flexible shaped phase change films in the following examples are as follows:

[0066] (1) Alkane phase change materials

[0067] Octadecane (commercially available, purity ≥98%);

[0068] Eicosane (commercially available, purity ≥98%);

[0069] Octacosane (commercially available, purity ≥98%);

[0070] Tris(2-dodecane) (commercially available, purity ≥98%);

[0071] Tetradecane (commercially available, purity ≥98%);

[0072] (2) Silica aerogel

[0073] Silica aerogel (commercially available, specific surface area 600-1200 g / m²);

[0074] (3) Flexible methyl silicone resin

[0075] 102-methyl silicone resin (Guangzhou Huigu New Material Technology Co., Ltd., etc.);

[0076] (4) Preparation of shaped phase change powders

[0077] First, the alkane phase change material is heated to 100°C in an oven until it is completely melted into a liquid state. Then, the liquid alkane phase change material is mixed with hydrophobic silica aerogel in a ratio of 5:1 to 9:1 and allowed to cool naturally to form a shaped phase change block. Next, the shaped phase change block is pulverized into shaped phase change powder with a particle size of 10 to 1000 μm using a pulverizer.

[0078] (5) Preparation of flexible shape-stabilized phase change film

[0079] The shaped phase change powder is mixed with flexible methyl silicone resin at a ratio of 1:1 to 2:1, and then pressed into a phase change film blank in a mold. After curing at room temperature for 24 to 48 hours, the film is demolded to form a flexible shaped phase change film.

[0080] The average density of the flexible shaped phase change film was tested according to GB / T1463 standard.

[0081] The average phase transition enthalpy of the flexible shaped phase change film was tested according to GB / T 19466.3 standard.

[0082] Example 1

[0083] (1) First, octadecane is heated to 100°C in an oven until it is completely melted into a liquid state. Then, the liquid octadecane is mixed with hydrophobic silica aerogel (specific surface area 625 g / m²) in a ratio of 5:1 and cooled naturally to form a shaped phase change block. Then, the shaped phase change block is crushed into shaped phase change powder with a particle size of 10-1000 μm using a pulverizer.

[0084] (2) The shaped phase change powder obtained in step (1) is mixed with flexible methyl silicone resin at a ratio of 1:1, and then pressed into a phase change film blank in a mold. After curing at room temperature for 24-48 hours, the film is demolded to form a flexible shaped phase change film.

[0085] The average density of the flexible, shape-stabilized phase change film is 1000 kg / m³. 3 ;

[0086] The average phase transition enthalpy of the flexible shaped phase change film is 100 kJ / kg.

[0087] Example 2

[0088] (1) First, octacosane is heated to 100°C in an oven until it is completely melted into a liquid state. Then, the liquid octacosane is mixed with hydrophobic silica aerogel (specific surface area 762 g / m²) in a ratio of 6:1 and allowed to cool naturally to form a shaped phase change block. Then, the shaped phase change block is crushed into shaped phase change powder with a particle size of 10-1000 μm using a pulverizer.

[0089] (2) The shaped phase change powder obtained in step (1) is mixed with flexible methyl silicone resin at a ratio of 1.5:1, and then pressed into a phase change film blank in a mold. After curing at room temperature for 24 to 48 hours, the film is demolded to form a flexible shaped phase change film.

[0090] The average density of the flexible shaped phase change film is 970 kg / m³. 3 ;

[0091] The average phase transition enthalpy of the flexible shaped phase change film is 120 kJ / kg.

[0092] Example 3

[0093] (1) First, heat dodecane at 100°C in an oven until it is completely melted into a liquid state. Then, mix the liquid dodecane with hydrophobic silica aerogel (specific surface area 846 g / m²) at a ratio of 7:1 and allow it to cool naturally to form a shaped phase change block. Next, use a pulverizer to pulverize the shaped phase change block into shaped phase change powder with a particle size of 10-1000 μm.

[0094] (2) The shaped phase change powder obtained in step (1) is mixed with flexible methyl silicone resin at a ratio of 1.5:1, and then pressed into a phase change film blank in a mold. After curing at room temperature for 24 to 48 hours, the film is demolded to form a flexible shaped phase change film.

[0095] The average density of the flexible shaped phase change film is 950 kg / m³. 3 ;

[0096] The average phase transition enthalpy of the flexible shaped phase change film is 130 kJ / kg.

[0097] Example 4

[0098] (1) First, heat tetradecane at 100°C in an oven until it is completely melted into a liquid state. Then, mix the liquid tetradecane with hydrophobic silica aerogel (specific surface area 958 g / m²) at a ratio of 8:1 and allow it to cool naturally to form a shaped phase change block. Next, use a pulverizer to pulverize the shaped phase change block into shaped phase change powder with a particle size of 10-1000 μm.

[0099] (2) The shaped phase change powder obtained in step (1) is mixed with flexible methyl silicone resin at a ratio of 1.5:1, and then pressed into a phase change film blank in a mold. After curing at room temperature for 24 to 48 hours, the film is demolded to form a flexible shaped phase change film.

[0100] The average density of the flexible shaped phase change film is 930 kg / m³. 3 ;

[0101] The average phase transition enthalpy of the flexible shaped phase change film is 140 kJ / kg.

[0102] Example 5

[0103] (1) First, octacosane is heated to 100°C in an oven until it is completely melted into a liquid state. Then, the liquid octacosane is mixed with hydrophobic silica aerogel (specific surface area 1120 g / m²) at a ratio of 9:1 and cooled naturally to form a shaped phase change block. Then, the shaped phase change block is crushed into shaped phase change powder with a particle size of 10-1000 μm using a pulverizer.

[0104] (2) The shaped phase change powder obtained in step (1) is mixed with flexible methyl silicone resin at a ratio of 2:1, and then pressed into a phase change film blank in a mold. After curing at room temperature for 24-48 hours, the film is demolded to form a flexible shaped phase change film.

[0105] The average density of the flexible shaped phase change film is 920 kg / m³. 3 ;

[0106] The average phase transition enthalpy of the flexible shaped phase change film is 150 kJ / kg.

[0107] Example 6

[0108] (1) First, octacosane is heated to 100°C in an oven until it is completely melted into a liquid state. Then, the liquid octacosane is mixed with hydrophobic silica aerogel (specific surface area 625 g / m²) at a ratio of 5:1 and cooled naturally to form a shaped phase change block. Then, the shaped phase change block is crushed into shaped phase change powder with a particle size of 10-1000 μm using a pulverizer.

[0109] (2) The shaped phase change powder obtained in step (1) is mixed with flexible methyl silicone resin at a ratio of 2:1, and then pressed into a phase change film blank in a mold. After curing at room temperature for 24-48 hours, the film is demolded to form a flexible shaped phase change film.

[0110] The average density of the flexible shaped phase change film is 950 kg / m³. 3 ;

[0111] The average phase transition enthalpy of the flexible shaped phase change film is 130 kJ / kg.

[0112] Example 7

[0113] (1) First, heat eicosane at 100°C in an oven until it is completely melted into a liquid state. Then, mix the liquid eicosane with hydrophobic silica aerogel (specific surface area 1120 g / m²) at a ratio of 9:1 and allow it to cool naturally to form a shaped phase change block. Next, use a pulverizer to pulverize the shaped phase change block into shaped phase change powder with a particle size of 10-1000 μm.

[0114] (2) The shaped phase change powder obtained in step (1) is mixed with flexible methyl silicone resin at a ratio of 1:1, and then pressed into a phase change film blank in a mold. After curing at room temperature for 24-48 hours, the film is demolded to form a flexible shaped phase change film.

[0115] The average density of the flexible shaped phase change film is 900 kg / m³. 3 ;

[0116] The average phase transition enthalpy of the flexible shaped phase change film is 130 kJ / kg.

[0117] like Figure 1 The SEM morphology and elemental distribution diagram of the flexible shaped phase change film of Embodiment 1 of the present invention show that the silicone resin forms a good coating on the phase change powder, which improves the structural and performance stability of the flexible shaped phase change film. Figure 2 This is an adhesion diagram of the flexible shaped phase change film of the present invention on the surface of an arc-shaped structure, showing that the flexible shaped phase change film has good stability when it is bonded and fixed on the surface of arc-shaped structures such as aircraft cabin walls and irregularly shaped surfaces of instruments and equipment.

[0118] The higher the mass ratio of alkane to hydrophobic aerogel and the higher the mass ratio of phase change powder to silicone resin, the higher the average phase change enthalpy of the flexible shaped phase change film.

[0119] The present invention has been described in detail above with reference to specific embodiments and exemplary examples; however, these descriptions should not be construed as limiting the present invention. Those skilled in the art will understand that various equivalent substitutions, modifications, or improvements can be made to the technical solutions and embodiments of the present invention without departing from the spirit and scope of the invention, and all such modifications and improvements fall within the scope of the present invention. The scope of protection of the present invention is defined by the appended claims.

[0120] The contents not described in detail in this specification are common knowledge to those skilled in the art.

Claims

1. A flexible set phase change film, characterized by, A phase change material 50-90 parts by mass; A silica aerogel 10 parts by mass; A flexible silicone resin 30-100 parts by mass; The phase change material is an alkane-based phase change material containing a methyl or ethyl group. The phase change material includes one or more of octadecane to tetracontane.

2. A flexible set phase change film according to claim 1, wherein The silica aerogel is a hydrophobically treated silica aerogel; 3. A flexible set phase change film according to claim 1, wherein The pore surface of the silica aerogel contains a methyl or ethyl group; The specific surface area of the silica aerogel is 600-1200 g / m2. The flexible silicone resin includes a room temperature curable flexible methyl silicone resin.

4. The flexible set phase change film of claim 1 wherein, The flexible silicone resin is an addition type 102 methyl silicone resin.

5. A flexible set phase change film according to claim 4, wherein The method includes:

6. A process for the preparation of a flexible set phase change film according to any one of claims 1 to 5, characterized in that, Heating the alkane-based phase change material in an oven to completely melt into a liquid state; Mixing the liquid alkane-based phase change material with the silica aerogel uniformly and naturally cooling to form a shaped phase change block; Crushing the shaped phase change block to obtain a shaped phase change powder; Mixing the shaped phase change powder with the flexible methyl silicone resin and placing it in a mold, and pressing to obtain a phase change film blank; After room temperature curing of the phase change film blank, demolding to form a flexible shaped phase change film. The particle size of the shaped phase change powder is 10-1000 μm; 7. The method for preparing a flexible, shaped phase change film according to claim 6, characterized in that, When the phase change film blank is cured at room temperature, the curing time is 24-48 h. The liquid alkane-based phase change material is mixed with the silica aerogel at a mass ratio of 5:1 to 9:1; 8. The method for preparing a flexible shaped phase change film according to claim 6, characterized in that, Let the specific surface area of the silica aerogel be S: When 600 g / m2≤S<700 g / m2, the mass ratio of the liquid alkane-based phase change material to the silica aerogel is 5:1; When 700 g / m2≤S<800 g / m2, the mass ratio of the liquid alkane-based phase change material to the silica aerogel is 6:1; When 800 g / m2≤S<900 g / m2, the mass ratio of the liquid alkane-based phase change material to the silica aerogel is 7:1; When 900 g / m2≤S<1000 g / m2, the mass ratio of the liquid alkane-based phase change material to the silica aerogel is 8:1; When 1000 g / m2≤S<1200 g / m2, the mass ratio of the liquid alkane-based phase change material to the silica aerogel is 9:

1. The mass ratio of the shaped phase change powder to the flexible methyl silicone resin is 1:1 to 2:

1.

9. The method for preparing a flexible, shaped phase change film according to claim 6, characterized in that, ​

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