Preparation method of ceramic fiber and aramid fiber composite aerogel thermal insulation material

Abstract

The invention relates to the technical field of high-temperature thermal insulation materials, and particularly discloses a preparation method of a ceramic fiber and aramid fiber composite aerogel thermal insulation material, which comprises the following steps: S1, selecting ceramic fibers and aramid fibers to be compounded as a reinforced framework material; s2, nano-scale SiO2 or Al2O3 aerogel is introduced into the fiber matrix through a sol-gel method; s3, improving the interface bonding force between the fiber and the aerogel through a surface treatment technology; s4, forming a stable porous structure through normal-pressure drying or supercritical drying; s5, performing multi-layer compounding on the aerogel heat insulation material by using environment-friendly alcohol-resistant glue, so that the whole structure has flexibility and functionality; the material prepared by the method can work at the temperature of 800 DEG C, and the normal-temperature heat conductivity coefficient is 1t; the heat conductivity coefficient is still 1t under the condition that the temperature is 800 DEG C; 0.18 W / (m * K); the density controllable range of the material is 250-350kg / m < 3 >, and the material has the characteristics of bendability, impact resistance and low thermal capacity, also has the characteristic of high insulation, and is particularly suitable for application in the new energy industry and the electrical insulation industry.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of high-temperature thermal insulation materials, in particular to a preparation method of a ceramic fiber and aramid fiber composite aerogel thermal insulation material. BACKGROUND

[0002] Aerogel refers to a kind of nanoscale porous solid material formed by replacing the liquid phase in the gel with gas through sol-gel method and a certain drying method; for example, gelatin, gum arabic, silica gel, hair, nails, etc. Aerogel also has the properties of gel, that is, it has the functions of swelling, thixotropy and syneresis; in industrial production and new energy vehicle application scenarios, as the heat density continues to rise, the performance requirements of thermal insulation and fireproof materials are becoming higher and higher; although traditional thermal insulation materials such as glass wool, rock wool and aluminum silicate fiber have certain high-temperature performance and thermal insulation capacity, they generally have problems.

[0003] High thermal conductivity and poor thermal efficiency: the thermal conductivity coefficient of conventional materials is generally greater than 0.04 W / (m.K), which is difficult to meet the requirements of high efficiency and energy saving; poor flexibility and weak structure adaptability: the material is easy to crack at high temperature and is not suitable for coating complex-shaped parts; short service life and poor stability: the performance is obviously attenuated after multiple thermal cycles, and powdering or slagging problems are easy to occur. SUMMARY

[0004] The application aims to solve the above technical problems and provide a preparation method of a ceramic fiber and aramid fiber composite aerogel thermal insulation material.

[0005] In order to achieve the above-mentioned purpose, the following technical solutions are adopted in the application:

[0006] The technical scheme adopted by the application to solve the technical problems is: the preparation method of the ceramic fiber and aramid fiber composite aerogel thermal insulation material comprises the following steps:

[0007] S1: selecting ceramic fiber and aramid fiber composite as reinforcing framework material;

[0008] S2: introducing nanoscale SiO2 or Al2O3 aerogel into the fiber matrix by sol-gel method;

[0009] S3: improving the interfacial bonding force between the fiber and the aerogel through surface treatment technology;

[0010] S4: forming a stable porous structure through normal pressure drying or supercritical drying;

[0011] S5: using environmentally friendly alcohol-resistant glue for multilayer composite aerogel thermal insulation material, so that the overall structure has flexibility and functionality.

[0012] Further, the ceramic fiber is selected from the specifications of thickness 2mm-4mm and density 190kg / m3, and the chopped aramid fiber is uniformly mixed at a mass ratio of 30%, so that the composite base material has heat resistance and high strength.

[0013] Further, the surface of the ceramic-aramid mixed fiber is treated by anhydrous ethanol or low-temperature plasma to remove impurities and improve hydrophilicity and adhesion activity.

[0014] The ceramic fiber and aramid fiber composite aerogel thermal insulation material preparation method has the following beneficial effects:

[0015] 1. The material prepared by the method has a working temperature of 800℃, a normal temperature thermal conductivity coefficient of <0.02W / (m·K), and a thermal conductivity coefficient of <0.18W / (m·K) at 800℃; the material density is controllable in the range of 250-350kg / m 3 , and has the characteristics of bendability, impact resistance and low heat capacity. BRIEF DESCRIPTION OF DRAWINGS

[0016] The specific embodiments of the present application will be further described in detail below with reference to the accompanying drawings;

[0017] Figure 1 It is a schematic diagram of a ceramic fiber and aramid fiber composite aerogel thermal insulation material preparation method. DETAILED DESCRIPTION

[0018] It should be understood that the specific embodiments described herein are only used to explain the present application, and are not used to limit the present application.

[0019] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0020] It should be noted that all directional indications (such as up-down-left-right-front-back…) in the embodiments of the present application are only used to explain the relative position relationship-movement between the components in a certain posture (as shown in the drawings), and if the certain posture changes, the directional indications also change accordingly. The connection can be direct connection or indirect connection.

[0021] Please refer to Figure 1 The ceramic fiber and aramid fiber composite aerogel thermal insulation material preparation method includes:

[0022] S1: Select ceramic fiber and aramid fiber composite as reinforcing framework material;

[0023] S2: Introduce nano-sized SiO2 or Al2O3 aerogel into the fiber matrix by sol-gel method;

[0024] S3: Improve the interfacial bonding between fibers and aerogel through surface treatment technology;

[0025] S4: Form stable porous structure by normal pressure drying or supercritical drying;

[0026] S5: Use environmentally friendly alcohol-resistant glue for multilayer composite aerogel insulation material, so that the overall structure has flexibility and functionality.

[0027] The composite aerogel insulation material made by the preparation method can insulate higher temperature heat and protect the objects behind the composite aerogel insulation material.

[0028] The ceramic fiber is selected to have a thickness of 2-4 mm and a density of 190 kg / m3, and short aramid fiber is uniformly mixed at a mass ratio of 30%, so that the composite substrate has heat resistance and high strength, and can insulate higher temperature.

[0029] The surface of the ceramic-aramid fiber mixture is treated with anhydrous ethanol or low temperature plasma to remove impurities, improve hydrophilicity and adhesion activity, and keep the surface of the mixed fiber clean and tidy, so that the final aerogel insulation material has balanced and stable performance.

[0030] The preparation of the aerogel insulation material uses tetraethyl orthosilicate as the precursor, adds ethanol, distilled water and hydrochloric acid to adjust the pH to 2-4, and forms SiO2 sol after sufficient hydrolysis reaction at room temperature; The sol is uniformly coated on the surface of the ceramic-aramid fiber composite substrate, and gels at a controlled temperature of 40-60°C, which can form a porous, ultra-light and high-thermal insulation composite aerogel layer in the composite substrate.

[0031] The preparation of the aerogel insulation material uses normal pressure drying for 48 hours, or uses supercritical CO2 drying to maintain porosity and three-dimensional network structure, and then performs organic component removal heat treatment at 300°C to form a porous, ultra-light and high-thermal insulation composite aerogel layer. The water in the composite aerogel layer is removed by normal pressure drying for 48 hours and 300°C organic component removal heat treatment, so that the inside is kept dry, a large number of cavity structures are formed, and a porous, ultra-light and high-thermal insulation composite aerogel layer is formed.

[0032] The preparation process of the aerogel thermal insulation material uses ethanol-resistant immersion glue for interlayer bonding, ensuring that the multi-layer structure does not delaminate and fail in a high-temperature and humid environment; the glue content is controlled at 8±1%, and by strictly controlling the glue content, the thermal insulation performance is ensured, and at the same time, the multi-layer structure is ensured not to delaminate and fail in a high-temperature and humid environment, and the stability of long-term use is ensured.

[0033] In the combustion test of the thermal insulation material, the loss on ignition is 3%, the bending radius is greater than or equal to 5 mm, and the tensile strength is greater than or equal to 300 Kpa. After passing the combustion test, it is detected that the prepared aerogel thermal insulation material meets the design requirements.

[0034] In the description of the present specification, the description of the terms "one embodiment", "example", "specific example" and the like means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are contained in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0035] The basic principles, main features and advantages of the present application are shown and described above. It should be understood by those skilled in the art that the present application is not limited by the above embodiments, and the above embodiments and descriptions in the specification are only illustrative of the principles of the present application. Without departing from the spirit and scope of the present application, various changes and improvements can be made to the present application, and these changes and improvements all fall within the scope of the claimed present application.

Claims

1. A method for preparing a ceramic fiber and aramid fiber composite aerogel thermal insulation material, characterized in that; The preparation method comprises: S1: selecting ceramic fibers and aramid fibers as composite reinforcing framework materials; S2: introducing nano-sized SiO2 or Al2O3 aerogel into the fiber matrix through a sol-gel method; S3: improving the interfacial bonding force between the fibers and the aerogel through surface treatment technology; S4: forming a stable porous structure through normal pressure drying or supercritical drying; S5: using environmentally friendly alcohol-resistant glue to perform multilayer composite aerogel thermal insulation materials, so that the overall structure has flexibility and functionality.

2. The method for preparing the ceramic fiber and aramid fiber composite aerogel thermal insulation material according to claim 1, characterized in that: The ceramic fibers have a thickness of 2-4 mm and a density of 190 kg / m3, and short aramid fibers are uniformly mixed at a mass ratio of 30%, so that the composite substrate has heat resistance and high strength.

3. The method for preparing the ceramic fiber and aramid fiber composite aerogel thermal insulation material according to claim 1, characterized in that: The surface of the ceramic-aramid mixed fibers is treated with anhydrous ethanol or low-temperature plasma to remove impurities and improve hydrophilicity and adhesion activity.

4. The method for preparing the ceramic fiber and aramid fiber composite aerogel thermal insulation material according to claim 1, characterized in that: The preparation of the aerogel thermal insulation material uses tetraethyl orthosilicate as a precursor, adds ethanol, distilled water, and hydrochloric acid to adjust the pH to 2-4, and forms SiO2 sol after sufficient hydrolysis reaction at room temperature; the sol is uniformly coated on the surface of the ceramic-aramid fiber composite substrate, and gels at a controlled temperature of 40-60°C.

5. The method for preparing the ceramic fiber and aramid fiber composite aerogel thermal insulation material according to claim 1, characterized in that: The preparation of the aerogel thermal insulation material uses normal pressure drying for 48 hours, or uses supercritical CO2 drying to maintain porosity and three-dimensional network structure, and then performs organic component removal heat treatment at 300°C to form a composite aerogel layer with high porosity, ultra-lightness, and high thermal insulation performance.

6. The method of claim 1, wherein the ceramic fiber and aramid fiber composite aerogel thermal insulation is prepared by: The preparation process of the aerogel thermal insulation material uses alcohol-resistant immersion glue for interlayer bonding to ensure that the multilayer structure does not delaminate and fail in high-temperature and humid environments; the glue content is controlled at 8±1%.

7. The method for preparing the ceramic fiber and aramid fiber composite aerogel thermal insulation material according to claim 2, characterized in that: In the combustion test, the loss on ignition of the thermal insulation material is 3%, the bending radius is ≥5 mm, and the tensile strength is ≥300 KPa.

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