Thermal insulation composite material with low heat conductivity coefficient and preparation method thereof

Abstract

The invention discloses a thermal insulation composite material with a low heat conductivity coefficient and a preparation method thereof, and relates to the technical field of thermal insulation materials. The silicon dioxide aerogel is subjected to surface modification, high-proportion addition of the silicon dioxide aerogel is realized, and the process of extrusion granulation, injection molding processing and irradiation crosslinking is combined, so that the prepared thermal insulation composite material has remarkable superiority in the aspects of heat conductivity coefficient, mechanical property, environmental protection, safety performance and the like; the thermal insulation material is an ideal thermal insulation material and has a wide application prospect.

Description

Technical Field

[0001] The invention relates to the technical field of thermal insulation materials, and in particular to a thermal insulation composite material with low thermal conductivity and a preparation method thereof. Background Art

[0002] In the field of engineering plastic composite materials, especially in the fields of thermophysics engineering and construction engineering, the development and application of high-performance thermal insulation materials have always been an important research direction. The main function of thermal insulation materials is to reduce heat conduction, thereby maintaining temperature stability and reducing energy consumption. Among them, thermal conductivity is an important parameter to measure the performance of thermal insulation materials. The lower the thermal conductivity, the better the thermal insulation effect.

[0003] Existing thermal insulation materials mainly include organic thermal insulation materials and inorganic thermal insulation materials. Inorganic thermal insulation materials such as mineral wool, glass fiber, ceramics, etc., although they have good fire resistance, have high thermal conductivity and are not as good as organic thermal insulation materials. At the same time, the material preparation consumes a lot of energy and cannot be recycled and reused. Organic thermal insulation materials such as polystyrene foam (EPS) and polyurethane foam (PU), although they have good thermal insulation performance, are easily damaged during construction and use due to their poor mechanical properties, which affects the thermal insulation effect. They also have problems such as insufficient heat resistance, flammability and environmental pollution, which pose great safety hazards and limit their application. Therefore, developing a thermal insulation material that has both low thermal conductivity, good mechanical properties, and good environmental protection and safety performance is an important challenge facing current technology. Summary of the invention

[0004] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a thermal insulation composite material with low thermal conductivity and a preparation method thereof. The prepared thermal insulation composite material has significant advantages in thermal conductivity, mechanical properties, environmental protection and safety performance, and is an ideal thermal insulation material with broad application prospects.

[0005] The technical solution of the present invention is: In one aspect, the present invention provides a method for preparing a thermal insulation composite material with low thermal conductivity, comprising the following steps: S1 Silane coupling agent surface modification: spray and coat the silane coupling agent diluted with ethanol on the surface of the silica aerogel to modify the surface of the silica aerogel. After coating, let it stand for more than 45 minutes for standby use; S2: surface modification with a cross-linking sensitizer: spraying and coating the surface of the silica aerogel after the surface modification with the silane coupling agent in step S1, and standing for more than 60 minutes for later use; S3 twin-screw extrusion granulation: the silica aerogel after the surface modification of the cross-linking sensitizer in step S2 and the nylon substrate are mixed and granulated by a twin-screw extruder to obtain pellets; the twin-screw extruder can achieve uniform mixing of the silica aerogel after the surface modification of the cross-linking sensitizer and the nylon substrate to ensure the bonding strength of the two; S4 injection molding: the pellets in step S3 are processed by an injection molding machine to obtain a thermal insulation composite material; S5 irradiation crosslinking: The thermal insulation composite material is irradiated and crosslinked by an electron beam tester. The acceleration voltage of the electron beam tester is 100-400keV, the dose rate is 50-160kGy, and the treatment time is 2-6h, so as to obtain a thermal insulation composite material with low thermal conductivity. Through irradiation crosslinking treatment, the nylon substrate and the silica aerogel are highly crosslinked, which further improves the bonding force between the two and enhances the overall mechanical properties of the material.

[0006] Preferably, in steps S1 and S2, a high mixer with a spray valve device is used to spray and coat the silane coupling agent or cross-linking sensitizer diluted with ethanol on the surface of the silica aerogel at intervals of 1 minute.

[0007] Preferably, the rotation speed of the high speed mixer is 400-1200 rpm, and the mixing time is 5-20 min.

[0008] Preferably, in step S1, the mass of the silane coupling agent is 0.01-0.3% of the total mass of the silane coupling agent and the silica aerogel.

[0009] Preferably, in step S2, the cross-linking sensitizer is trimethylolpropane trimethacrylate (TMPTMA).

[0010] Preferably, in step S2, the mass of the cross-linking sensitizer is 0.02-5% of the total mass of the silica aerogel after surface modification by the cross-linking sensitizer and the silane coupling agent.

[0011] Preferably, in step S3, the mass of the silica aerogel after the surface modification by the cross-linking sensitizer is 20-70% of the total mass of the silica aerogel after the surface modification by the cross-linking sensitizer and the nylon substrate.

[0012] On the other hand, the present invention provides a thermal insulation composite material with low thermal conductivity, which is prepared by the above-mentioned method for preparing the thermal insulation composite material with low thermal conductivity.

[0013] Compared with the prior art, the present invention has the following beneficial effects: 1. The thermal insulation composite material prepared by the present invention has an ultra-low thermal conductivity and excellent thermal insulation effect, which meets the demand for high-efficiency thermal insulation materials in the field of construction engineering. In addition, the present invention realizes a high degree of combination of nylon matrix and silica aerogel through the process of first extrusion granulation, injection molding and then irradiation cross-linking, improves the mechanical properties of the overall product, and solves the problem that the existing thermal insulation materials generally have poor mechanical properties, are easy to fail during processing and use, and affect the thermal insulation effect. In addition, the thermal insulation composite material of the present invention adopts inorganic fillers and environmentally friendly nylon substrates, does not contain harmful substances, and meets environmental protection and safety standards. Therefore, the present invention not only solves the problem of high thermal conductivity and poor thermal insulation effect of inorganic thermal insulation materials, but also solves the problem of environmental pollution of existing organic thermal insulation materials. The thermal insulation composite material of the present invention has significant advantages in thermal conductivity, mechanical properties, environmental protection and safety performance, and is an ideal thermal insulation material with broad application prospects.

[0014] 2. The present invention can achieve a high proportion of silica aerogel filling and compounding, and the effective addition amount in the nylon substrate can reach up to 70wt.%. The prepared thermal insulation composite material has excellent thermal insulation performance and can significantly reduce the thermal conductivity of the thermal insulation composite material, thereby improving the thermal insulation effect. Compared with the prior art, the present invention can achieve a higher filler filling ratio while ensuring the mechanical properties of the thermal insulation composite material, further improving the thermal insulation effect.

[0015] 3. The present invention uses a silane coupling agent to modify the surface of the silica aerogel, so that the nylon substrate and the silica aerogel have high compatibility, which can effectively prevent the silica aerogel from falling off during the construction and use of the thermal insulation composite material, and ensure its long-term thermal insulation effect; then the silica aerogel is surface modified by a cross-linking sensitizer, so that the processed thermal insulation composite material is cross-linked after irradiation, which greatly improves the bonding force between the nylon substrate and the silica aerogel, making the overall structure of the thermal insulation composite material more compact and excellent in mechanical properties. Compared with the prior art, the thermal insulation composite material of the present invention has higher strength and toughness, can better resist external impact and deformation, and prolongs its service life.

[0016] 4. Since silica aerogel is an inorganic material with ultra-high porosity (more than 90%), it is a poor conductor of heat, with a thermal conductivity of 0.01W / (m·K), while the thermal conductivity of conventional nylon resin is 0.2-0.4W / (m·K). The bulk density of silica aerogel is extremely low, and it can effectively block the thermal conductivity path of nylon resin itself when it has good dispersibility in nylon resin. During the processing, it is very important to surface modify the silica aerogel with a silane coupling agent to ensure that the silica aerogel is well dispersed in the nylon substrate, so as to avoid stratification and phase separation between the nylon substrate and the silica aerogel, and construct a thermal conductivity path. The mechanical properties of traditional composite materials filled with high proportions of fillers are extremely poor, but the present invention performs radiation cross-linking after injection molding, so that the molded parts have very good mechanical properties and heat resistance. Therefore, the present invention adds silica aerogel and combines the radiation cross-linking process to make the thermal conductivity of the thermal insulation composite material ultra-low, which can provide better thermal insulation effect, reduce energy consumption, and reduce operating costs. DETAILED DESCRIPTION

[0017] In order to enable persons skilled in the art to better understand the technical solution of the present invention, the technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention.

[0018] Example 1 The method for preparing the thermal insulation composite material with low thermal conductivity of this embodiment comprises the following steps: S1 Silane coupling agent surface modification: A high-speed mixer with a spray valve device (automatic spray high-speed mixer, Shanghai Juyou Machinery Factory) was used to spray and coat the silane coupling agent KH-550 diluted with ethanol on the surface of the silica aerogel at intervals of 1 min to modify the surface of the silica aerogel, wherein the mass ratio of ethanol to silane coupling agent KH-550 was 80:20, the mass of silane coupling agent KH-550 was 0.1% of the total mass of silane coupling agent KH-550 and silica aerogel, the speed of the high-speed mixer was 600 rpm, and the mixing time was 10 min; after coating, the mixture was allowed to stand for 45 min for standby use; S2: Surface modification with cross-linking sensitizer: spray the cross-linking sensitizer TMPTMA on the surface of the silica aerogel after the surface modification with the silane coupling agent in step S1 through a high-speed mixer, wherein the mass of TMPTMA is 0.8% of the total mass of the silica aerogel after the surface modification with the TMPTMA and the silane coupling agent, the speed of the high-speed mixer is 600 rpm, and the mixing time is 10 min; after the coating is completed, the mixture is allowed to stand for 60 min for standby use; S3 twin-screw extrusion granulation: the silica aerogel after the surface modification of the cross-linking sensitizer in step S2 and the nylon 6 substrate are mixed and granulated by a twin-screw extruder, wherein the mass of the silica aerogel after the surface modification of the cross-linking sensitizer accounts for 61.8% of the total mass of the silica aerogel after the surface modification of the cross-linking sensitizer and the nylon substrate, the temperature of the twin-screw extruder is 255°C, the screw speed is 200rpm, the strands are cooled and pelletized to obtain pellets; S4 Injection molding: The pellets in step S3 are processed by an injection molding machine, the temperature of the injection molding machine is 260° C., the pressure is 10 MPa, and the holding time is 10 s to obtain a thermal insulation composite material; S5 irradiation crosslinking: The thermal insulation composite material was subjected to irradiation crosslinking treatment by electron beam tester MEB-200 (Beijing Lituo Xinda Technology Co., Ltd.), with an acceleration voltage of 200 keV, a dose rate of 100 kGy, and a treatment time of 2 h, to obtain a thermal insulation composite material with low thermal conductivity.

[0019] Example 2 The method for preparing the thermal insulation composite material with low thermal conductivity of this embodiment comprises the following steps: S1 Silane coupling agent surface modification: A high-speed mixer with a spray valve device was used to spray and coat the silane coupling agent KH-550 diluted with ethanol on the surface of the silica aerogel at intervals of 1 minute to modify the surface of the silica aerogel, wherein the mass ratio of ethanol to silane coupling agent KH-550 was 80:20, the mass of silane coupling agent KH-550 was 0.3% of the total mass of silane coupling agent KH-550 and silica aerogel, the speed of the high-speed mixer was 400 rpm, and the mixing time was 20 minutes; after coating, the mixture was allowed to stand for 50 minutes for standby use; S2: Surface modification with cross-linking sensitizer: spray the cross-linking sensitizer TMPTMA on the surface of the silica aerogel after the surface modification with the silane coupling agent in step S1 through a high-speed mixer, wherein the mass of TMPTMA is 5% of the total mass of the silica aerogel after the surface modification with the TMPTMA and the silane coupling agent, the speed of the high-speed mixer is 600 rpm, and the mixing time is 10 min; after the coating is completed, the mixture is allowed to stand for 65 min for standby use; S3 twin-screw extrusion granulation: the silica aerogel after the surface modification of the cross-linking sensitizer in step S2 and the nylon 6 substrate are mixed and granulated by a twin-screw extruder, wherein the mass of the silica aerogel after the surface modification of the cross-linking sensitizer accounts for 21.8% of the total mass of the silica aerogel after the surface modification of the cross-linking sensitizer and the nylon substrate, the temperature of the twin-screw extruder is 255°C, the screw speed is 200rpm, the strands are cooled and pelletized to obtain pellets; S4 Injection molding: The pellets in step S3 are processed by an injection molding machine, the temperature of the injection molding machine is 260° C., the pressure is 10 MPa, and the holding time is 10 s to obtain a thermal insulation composite material; S5 irradiation crosslinking: The thermal insulation composite material is subjected to irradiation crosslinking treatment by electron beam tester MEB-200, with an acceleration voltage of 400keV, a dose rate of 50kGy, and a treatment time of 4h, to obtain a thermal insulation composite material with low thermal conductivity.

[0020] Example 3 The method for preparing the thermal insulation composite material with low thermal conductivity of this embodiment comprises the following steps: S1 Silane coupling agent surface modification: A high-speed mixer with a spray valve device was used to spray and coat the silane coupling agent KH-550 diluted with ethanol on the surface of the silica aerogel at intervals of 1 minute to modify the surface of the silica aerogel, wherein the mass ratio of ethanol to silane coupling agent KH-550 was 80:20, the mass of silane coupling agent KH-550 was 0.01% of the total mass of silane coupling agent KH-550 and silica aerogel, the speed of the high-speed mixer was 1200 rpm, and the mixing time was 5 minutes; after the coating was completed, it was left to stand for 45 minutes for use; S2: Surface modification with cross-linking sensitizer: spray the cross-linking sensitizer TMPTMA on the surface of the silica aerogel after the surface modification with the silane coupling agent in step S1 through a high-speed mixer, wherein the mass of TMPTMA is 0.02% of the total mass of the silica aerogel after the surface modification with the TMPTMA and the silane coupling agent, the speed of the high-speed mixer is 600 rpm, and the mixing time is 10 min; after the coating is completed, the mixture is allowed to stand for 60 min for standby use; S3 twin-screw extrusion granulation: the silica aerogel after the surface modification of the cross-linking sensitizer in step S2 and the nylon 6 substrate are mixed and granulated by a twin-screw extruder, wherein the mass of the silica aerogel after the surface modification of the cross-linking sensitizer accounts for 70% of the total mass of the silica aerogel after the surface modification of the cross-linking sensitizer and the nylon substrate, the temperature of the twin-screw extruder is 255°C, the screw speed is 200rpm, the strands are cooled and pelletized to obtain pellets; S4 Injection molding: The pellets in step S3 are processed by an injection molding machine, the temperature of the injection molding machine is 260° C., the pressure is 10 MPa, and the holding time is 10 s to obtain a thermal insulation composite material; S5 irradiation crosslinking: The thermal insulation composite material is subjected to irradiation crosslinking treatment by electron beam tester MEB-200, with an acceleration voltage of 100keV, a dose rate of 160kGy, and a treatment time of 6h, to obtain a thermal insulation composite material with low thermal conductivity.

[0021] Comparative Example 1 The difference from Example 1 is that white carbon black is used to replace the silica aerogel in Example 1, and the powder particle D50 of the white carbon black is about 3 μm.

[0022] Comparative Example 2 The difference from Example 1 is that the silica aerogel and the nylon 6 substrate after surface modification with the cross-linking sensitizer in step S2 are first irradiated and cross-linked in step S5, and then twin-screw extrusion granulation in step S3 and injection molding are performed in step S4.

[0023] Comparative Example 3 The difference from Example 1 is that in step S2, the UV irradiation crosslinking agent EBECRYL 810 is used to replace the crosslinking sensitizer TMPTMA in Example 1.

[0024] Comparative Example 4 The difference from Example 1 is that in step S2, the radiation cross-linking agent triallyl isocyanurate (TAIC) is used to replace the cross-linking sensitizer TMPTMA in Example 1.

[0025] Comparative Example 5 The difference from Example 1 is that in step S5, the acceleration voltage of the electron beam experiment instrument is 800 keV, the dose rate is 200 kGy, and the processing time is 6 h.

[0026] Comparative Example 6 The difference from Example 1 is that in step S1, the silica aerogel is mixed with the silane coupling agent KH550, the mass of the silane coupling agent KH-550 is 0.1% of the total mass of the silane coupling agent KH-550 and the silica aerogel, and then added to 1000 mL of anhydrous ethanol, ultrasonically dispersed for 45 minutes, and then dried to constant weight to obtain the silica aerogel surface-modified with the silane coupling agent; in step S2, the silica aerogel surface-modified with the silane coupling agent is mixed with the cross-linking sensitizer TMPTMA, the mass of TMPTMA is 0.8% of the total mass of the silica aerogel surface-modified with the TMPTMA and the silane coupling agent, added to 1000 mL of anhydrous ethanol, ultrasonically dispersed for 60 minutes, and then dried to constant weight to obtain the silica aerogel surface-modified with the cross-linking sensitizer.

[0027] The thermal conductivity and mechanical properties of the thermal insulation composite materials prepared in Examples 1-3 and Comparative Examples 1-6 were tested, and the test results are shown in Table 1. The thermal conductivity was tested using a laser thermal conductivity meter, and the mechanical properties were tested using a universal material testing machine.

[0028] Table 1 Performance test results of thermal insulation composite materials prepared in Examples 1-3 and Comparative Examples 1-6

[0029] It can be seen from Table 1 that the thermal insulation composite materials prepared in Examples 1-3 of the present invention have ultra-low thermal conductivity, excellent thermal insulation effect, and can meet the requirements of downstream applications for high-efficiency thermal insulation materials; at the same time, through the process of extrusion granulation, injection molding and then radiation cross-linking, a high degree of integration of the nylon matrix and the silica aerogel is achieved, thereby improving the mechanical properties of the overall product.

[0030] Examples 1-3 mainly investigate the effects of different addition ratios of silica aerogel in the nylon matrix on the thermal conductivity and mechanical properties of the thermal insulation composite material. The present invention can ensure that when the addition amount of silica aerogel in the nylon matrix is ​​as high as 70wt.%, the prepared thermal insulation composite material still has relatively ideal mechanical properties, and the thermal conductivity is as low as 0.017W / (m·K).

[0031] Compared with Example 1, conventional white carbon black was used in Comparative Example 1 to replace silica aerogel, and it was found that the thermal conductivity of the prepared thermal insulation composite material reached 0.56 W / (m·K), which was much higher than that of the thermal insulation composite material of Example 1. This is because conventional white carbon black itself has a dense texture, and the thermal insulation composite material prepared from low-porosity white carbon black and nylon substrate does not have thermal insulation function.

[0032] Compared with Example 1, Comparative Example 2 changes the order of radiation crosslinking treatment, firstly, the silica aerogel and the nylon 6 substrate after surface modification of the crosslinking sensitizer in step S2 are subjected to radiation crosslinking in step S5, and then the twin-screw extrusion granulation in step S3 and the injection molding in step S4 are carried out. During the process, it is found that the later processing is very difficult. This is because the radiation causes the crosslinking sensitizer TMPTMA to produce multiple active free radicals, which react with the terminal amino group and carboxyl group of nylon 6, resulting in excessive filling pressure of the later injection molding machine, and the overall density of the prepared thermal insulation composite material is reduced, which leads to a reduction of its mechanical properties by more than 50% compared with Example 1.

[0033] Compared with Example 1, Comparative Example 3 uses a UV radiation crosslinking agent instead of the crosslinking sensitizer TMPTMA. It is found that the mechanical properties of the prepared thermal insulation composite material are greatly reduced (reduced by more than 61%). This is because UV radiation has poor penetration into the thermal insulation composite material, and only the skin layer undergoes a crosslinking reaction, while the internal UV radiation crosslinking agent and the nylon 6 substrate are not stimulated to undergo a crosslinking reaction.

[0034] Compared with Example 1, Comparative Example 4 uses the radiation crosslinking agent TAIC instead of the crosslinking sensitizer TMPTMA. It is found that the mechanical properties of the prepared thermal insulation composite material are reduced by more than 18% compared with Example 1. This is because TAIC requires higher power radiation to excite the same concentration of active free radicals to achieve crosslinking reaction compared with TMPTMA.

[0035] Compared with Example 1, in Comparative Example 5, after applying greater irradiation energy to the thermal insulation composite material, the mechanical properties of the prepared thermal insulation composite material did not improve, but instead decreased. This is because the excessive irradiation energy did not significantly increase the crosslinking degree of the product to offset the performance degradation caused by material aging due to irradiation; at the same time, the thermal conductivity increased from 0.025W / (m·K) to 0.039W / (m·K), which is presumably due to the excessive irradiation causing local carbonization of the thermal insulation composite material to form a heat conduction path.

[0036] Compared with Example 1, Comparative Example 6 uses a two-time ultrasonic dispersion method to modify the surface of silica aerogel. Since the high porosity structure of silica aerogel is filled to varying degrees during ultrasonic treatment in ethanol, and the subsequent drying cannot completely remove the ethanol that enters the micropores, the thermal conductivity of the final thermal insulation composite material increases to 0.16W / (m·K); at the same time, there are many small molecules remaining, which seriously attenuates the mechanical properties of the thermal insulation composite material. In addition, it was found during the ultrasonic treatment process that the ultrasonic dispersion method is not suitable for industrial operations because there are problems such as high workload and high cost of ethanol recovery in the later stage.

[0037] The thermal insulation composite material with low thermal conductivity prepared by the present invention is highly combined with the nylon substrate and the silica aerogel by filling a high proportion of silica aerogel and combining the radiation cross-linking process, thereby achieving a perfect combination of ultra-low thermal conductivity and excellent mechanical properties. This thermal insulation composite material can not only solve the environmental pollution problem of existing organic thermal insulation materials, but also make up for the defect of high thermal conductivity of inorganic thermal insulation materials, thus having important application value in the field of materials science. At the same time, the thermal insulation composite material prepared by the present invention, due to its ultra-low thermal conductivity, can effectively reduce heat conduction, maintain temperature stability, and reduce energy consumption, so it also has broad application prospects in the field of thermal physics engineering.

Claims

1. A method for preparing a thermal insulation composite material with low thermal conductivity, characterized in that: The following steps are involved: S1 Silane coupling agent surface modification: spray and coat the silane coupling agent diluted with ethanol on the surface of the silica aerogel to modify the surface of the silica aerogel. After coating, let it stand for more than 45 minutes for standby use; S2: surface modification with a cross-linking sensitizer: spraying and coating the surface of the silica aerogel after the surface modification with the silane coupling agent in step S1, and standing for more than 60 minutes for later use; S3 twin-screw extrusion granulation: mixing and granulating the silica aerogel surface-modified with the cross-linking sensitizer in step S2 and the nylon substrate through a twin-screw extruder to obtain pellets; S4 injection molding: the pellets in step S3 are processed by an injection molding machine to obtain a thermal insulation composite material; S5 irradiation crosslinking: The thermal insulation composite material is subjected to irradiation crosslinking treatment by an electron beam tester. The acceleration voltage of the electron beam tester is 100-400keV, the dose rate is 50-160kGy, and the treatment time is 2-6h, so as to obtain a thermal insulation composite material with low thermal conductivity.

2. The method for preparing a thermal insulation composite material with low thermal conductivity according to claim 1, characterized in that: In steps S1 and S2, a high mixer with a spray valve device is used to spray and coat the silane coupling agent or cross-linking sensitizer diluted with ethanol on the surface of the silica aerogel at intervals of 1 minute.

3. The method for preparing a thermal insulation composite material with low thermal conductivity as claimed in claim 2, characterized in that: The speed of the high speed mixer is 400-1200 rpm, and the mixing time is 5-20 min.

4. The method for preparing a thermal insulation composite material with low thermal conductivity according to claim 1, characterized in that: In step S1, the mass of the silane coupling agent is 0.01-0.3% of the total mass of the silane coupling agent and the silica aerogel.

5. The method for preparing a thermal insulation composite material with low thermal conductivity as claimed in claim 1, characterized in that: In step S2, the cross-linking sensitizer is trimethylolpropane trimethacrylate.

6. The method for preparing a thermal insulation composite material with low thermal conductivity as claimed in claim 1, characterized in that: In step S2, the mass of the cross-linking sensitizer is 0.02-5% of the total mass of the silica aerogel after surface modification by the cross-linking sensitizer and the silane coupling agent.

7. The method for preparing a thermal insulation composite material with low thermal conductivity according to claim 1, characterized in that: In step S3, the mass of the silica aerogel after the surface modification by the cross-linking sensitizer is 20-70% of the total mass of the silica aerogel after the surface modification by the cross-linking sensitizer and the nylon substrate.

8. A thermal insulation composite material with low thermal conductivity, characterized in that: The thermal insulation composite material is prepared by the preparation method of the thermal insulation composite material with low thermal conductivity as described in any one of claims 1 to 7.

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