阅读说明：本技术 一种耐高温隔热保温碳毡的制备方法、制得的保温碳毡及其应用 (Preparation method of high-temperature-resistant heat-insulation carbon felt, prepared heat-insulation carbon felt and application of heat-insulation carbon felt ) 是由 卜宇轩 肖浩 肖孝天 张明瑜 刘亚鹏 宋良芬 吴清贤 马翔翔 黄猛 于 2021-09-28 设计创作，主要内容包括：本发明公开一种耐高温隔热保温碳毡的制备方法,涉及保温隔热材料技术领域,本发明包括以下步骤：1)在真空或惰性气体氛围下,将聚合物泡沫进行碳化处理,得到预制软碳毡,所述聚合物泡沫为三聚氰胺泡沫或聚氨酯泡沫；2)将所述预制软碳毡放入化学气相沉积炉中沉积热解炭,得到所述耐高温隔热保温碳毡。本发明还提供采用上述方法制得的保温碳毡及其应用。本发明的有益效果在于：本发明将制备预制软碳毡的工艺简单,之后预制软碳毡放入化学气相沉积炉中沉积热解炭,使热解炭将软碳毡的炭网格包覆起来,有效阻碍裂纹的偏转和扩展,延长了预制软碳毡的使用寿命,并提升了保温碳毡的力学性能,本发明保温碳毡可作为保温材料用于多种保温炉中。(The invention discloses a preparation method of a high-temperature-resistant heat-insulating carbon felt, relating to the technical field of heat-insulating materials and comprising the following steps: 1) carbonizing polymer foam in vacuum or inert gas atmosphere to obtain a prefabricated soft carbon felt, wherein the polymer foam is melamine foam or polyurethane foam; 2) and putting the prefabricated soft carbon felt into a chemical vapor deposition furnace to deposit pyrolytic carbon to obtain the high-temperature-resistant heat-insulating carbon felt. The invention also provides the heat-preservation carbon felt prepared by the method and application thereof. The invention has the beneficial effects that: the preparation method of the invention has the advantages that the preparation process of the prefabricated soft carbon felt is simple, then the prefabricated soft carbon felt is placed into a chemical vapor deposition furnace to deposit pyrolytic carbon, the pyrolytic carbon is used for coating the carbon grids of the soft carbon felt, the deflection and the expansion of cracks are effectively hindered, the service life of the prefabricated soft carbon felt is prolonged, and the mechanical property of the heat preservation carbon felt is improved.)

1. A preparation method of a high-temperature-resistant heat-insulation heat-preservation carbon felt is characterized by comprising the following steps: the method comprises the following steps:

1) carbonizing polymer foam in vacuum or inert gas atmosphere to obtain a prefabricated soft carbon felt, wherein the polymer foam is melamine foam or polyurethane foam;

2) and putting the prefabricated soft carbon felt into a chemical vapor deposition furnace to deposit pyrolytic carbon to obtain the high-temperature-resistant heat-insulating carbon felt.

2. The preparation method of the high-temperature-resistant heat-insulating carbon felt according to claim 1, characterized by comprising the following steps: the polymer foam is melamine foam, and the prefabricated soft carbon felt specifically comprises the following steps: placing the melamine foam in a carbonization furnace, rapidly heating to 200-fold-organic-inorganic composite material 250 ℃ under a vacuum state or an inert gas atmosphere, keeping the temperature for 15-60min, then heating to 350-fold-organic-inorganic composite material 400 ℃, keeping the temperature for 30-120min, then heating to 700-fold-organic-inorganic composite material 750 ℃, keeping the temperature for 30-120min, then heating to 900-fold-organic-inorganic composite material 950 ℃, keeping the temperature for 15-60min, then heating to 1000-fold-organic-inorganic composite material 1200 ℃, keeping the temperature for 60-120min, and then cooling to room temperature along with the furnace to obtain the prefabricated soft carbon felt.

3. The preparation method of the high-temperature-resistant heat-insulating carbon felt according to claim 2, characterized by comprising the following steps: heating to 350-400 ℃ at a heating rate of 0.2-1 ℃/min; heating to 700-750 ℃ at a heating rate of 1-5 ℃/min; heating to 900-950 ℃ at a heating rate of 0.2-1 ℃/min; the temperature is raised to 1000-1200 ℃ at a temperature rise rate of 1-5 ℃/min.

4. The preparation method of the high-temperature-resistant heat-insulating carbon felt according to claim 1, characterized by comprising the following steps: the density of the melamine foam is 0.008-0.01g/cm³。

5. The preparation method of the high-temperature-resistant heat-insulating carbon felt according to claim 1, characterized by comprising the following steps: under the vacuum state, the chemical vapor deposition furnace is quickly heated to 500 ℃ of 300-.

6. The preparation method of the high-temperature-resistant heat-insulating carbon felt according to claim 5, characterized by comprising the following steps: heating to 800-1200 ℃ at a heating rate of 1-10 ℃/min.

7. The preparation method of the high-temperature-resistant heat-insulating carbon felt according to claim 1, characterized by comprising the following steps: the hydrocarbon gas is any one or a mixture of a plurality of natural gas, liquefied petroleum gas, methane, propylene and propane; the flow rate of the hydrocarbon gas is 50-100 sccm.

8. The preparation method of the high-temperature-resistant heat-insulating carbon felt according to claim 1, characterized by comprising the following steps: the inert gas is at least one of nitrogen and argon.

9. The high temperature resistant heat insulation carbon felt prepared by the method of any one of claims 1 to 8.

10. Use of the high temperature resistant heat insulating carbon felt prepared by the method of any one of claims 1 to 8 in heat preservation and insulation of a holding furnace.

Technical Field

The invention relates to the technical field of heat preservation and insulation materials, in particular to a preparation method of a high-temperature-resistant heat-insulation carbon felt, the prepared heat-insulation carbon felt and application thereof.

Background

The holding furnace (degreasing furnace, high-temperature carbonization furnace, CVD furnace, CVI furnace and the like) is widely applied to the fields of chemical industry, energy, aerospace and the like, a large amount of electric energy needs to be consumed, the heat insulation layer plays a vital role in the holding furnace, and the heat insulation felt with excellent high-temperature heat insulation effect can effectively reduce the diffusion of heat in the furnace, reduce the loss of heat and save energy.

At present, various heat preservation furnaces in China still adopt traditional felt heat insulation materials, the traditional felt heat insulation materials have the defects of low use temperature, poor heat insulation performance, high-temperature embrittlement, unstable thermal field and the like, and particularly after long-time use, once cracks appear, the traditional felt heat insulation materials are easy to expand, so that the use performance of the felt heat insulation materials is remarkably reduced until the felt heat insulation materials cannot be used, and the service life is remarkably shortened.

The patent with publication number CN103979994B discloses a heat preservation carbon felt, but the preparation method is complicated, and the prepared heat preservation carbon felt has high heat conductivity and high density.

Disclosure of Invention

The invention aims to solve the technical problems that the heat-preservation carbon felt in the prior art is high in heat conductivity coefficient and density, and provides a preparation method of a high-temperature-resistant heat-insulation carbon felt with low density and low heat conductivity coefficient, the prepared heat-preservation carbon felt and application thereof.

The invention solves the technical problems through the following technical means:

a preparation method of a high-temperature-resistant heat-insulating carbon felt comprises the following steps:

1) carbonizing polymer foam in vacuum or inert gas atmosphere to obtain a prefabricated soft carbon felt, wherein the polymer foam is melamine foam or polyurethane foam;

2) and putting the prefabricated soft carbon felt into a chemical vapor deposition furnace to deposit pyrolytic carbon to obtain the high-temperature-resistant heat-insulating carbon felt.

Has the advantages that: the polymer foam is carbonized to prepare the prefabricated soft carbon felt, the preparation process is simple, and the production cost is low. When the polymer foam is melamine foam, the melamine foam is porous and light.

The deposited pyrolytic carbon refers to a process of depositing carbon materials on a substrate from gaseous hydrocarbons through a high-temperature pyrolysis reaction. After the prefabricated soft carbon felt deposits the pyrolytic carbon, the pyrolytic carbon layer enters the inside of the carbon felt, and the carbon grids of the prefabricated soft carbon felt are covered, so that the deflection and the expansion of cracks are effectively hindered, the chemical corrosion resistance and the high temperature resistance of the prefabricated soft carbon felt are improved by more than 5 times, the service life of the prefabricated soft carbon felt is prolonged, and the mechanical properties of the prefabricated soft carbon felt, such as compression resistance, impact resistance and the like, are further improved.

The preparation method is simple, the cost is low, the high-temperature-resistant heat-insulation carbon felt prepared by the method is soft and elastic, is not easy to crack, has the characteristics of good heat insulation, tear resistance, good resilience, convenience in use, durability and the like, and is wide in application range.

Preferably, the inert gas is at least one of nitrogen and argon.

Preferably, the polymer foam is melamine foam, and the prefabricated soft carbon felt specifically comprises the following steps: placing the melamine foam in a carbonization furnace, rapidly heating to 200-fold-organic-inorganic composite material 250 ℃ under a vacuum state or an inert gas atmosphere, keeping the temperature for 15-60min, then heating to 350-fold-organic-inorganic composite material 400 ℃, keeping the temperature for 30-120min, then heating to 700-fold-organic-inorganic composite material 750 ℃, keeping the temperature for 30-120min, then heating to 900-fold-organic-inorganic composite material 950 ℃, keeping the temperature for 15-60min, then heating to 1000-fold-organic-inorganic composite material 1200 ℃, keeping the temperature for 60-120min, and then cooling to room temperature along with the furnace to obtain the prefabricated soft carbon felt.

Preferably, the temperature is raised to 350-400 ℃ at the temperature raising rate of 0.2-1 ℃/min; heating to 700-750 ℃ at a heating rate of 1-5 ℃/min; heating to 900-950 ℃ at a heating rate of 0.2-1 ℃/min; the temperature is raised to 1000-1200 ℃ at a temperature rise rate of 1-5 ℃/min.

Has the advantages that: the melamine foam has stronger temperature resistance, so that the temperature can be quickly raised to 200-250 ℃ in the low-temperature stage for early preheating, and the heat preservation time is not too long, so that the temperature is set to be 15-60 min; heating to 350-400 ℃ at a slow speed of 0.2-1 ℃/min, preserving heat for 30-120min, wherein the melamine foam begins to shrink in the temperature range, and in order to ensure the stability and uniformity of the organization structure of the melamine foam, heating is carried out for a long heat preservation time at a low speed so that the melamine foam uniformly and slowly shrinks and achieves certain stability; after the structure reaches a certain stability, the temperature is raised to 700-750 ℃ at a rapid rate of 1-5 ℃/min, and the temperature is preserved for 30-120min to achieve the effects of rapid carbonization and shaping; then heating to 900-; finally, heating at a fast speed of 1-5 ℃/min, preserving heat for 60-120min, and finally carbonizing and shaping; the five-step heating method can gradually and gradually shrink and carbonize the melamine foam, so that the melamine foam is prevented from shrinking too fast to cause uneven and unstable structure, and the excellent performance of the finally obtained carbon felt is ensured.

Preferably, the melamine foam has a density of 0.008 to 0.01g/cm³。

Has the advantages that: the melamine foam with the density ensures the porosity of the carbon felt, and simultaneously ensures that the pyrolytic carbon has good deposition effect on the prefabricated soft carbon felt and strong binding force. The obtained prefabricated soft carbon felt is soft, low in density, low in heat conductivity coefficient, uniform in thermal field and high in porosity.

Preferably, in a vacuum state, the chemical vapor deposition furnace is rapidly heated to 300-500 ℃, the temperature is kept constant for 30-60min, then the temperature is raised to 800-1200 ℃, the temperature is kept constant for 30-60min, inert gas is introduced until the gas pressure is 1-30kPa, then hydrocarbon gas is introduced to start deposition of pyrolytic carbon, after 5-60min, the introduction of hydrocarbon gas is stopped, and the furnace is taken out after vacuumizing and free cooling to below 300 ℃.

When the method is used for depositing the pyrolytic carbon by the prefabricated soft carbon, the reaction temperature is closely related to the microstructure of the pyrolytic carbon, and the deposition rate, the porosity and the possibility of later densification are influenced, namely, the microscopic morphologies of the pyrolytic carbon correspondingly generated by different reaction temperatures and reaction times are different, generally, the higher the temperature is, the more violent the compound cracking is, the more violent the reaction among the generated small molecular groups is, and the faster the deposition rate is. At the same time, the morphology of different carbon sources is different. Smooth layered carbon (SL) tends to be formed at low temperature, coarse layered carbon (RL) tends to be formed at medium temperature, and isotropic carbon tends to be formed at high temperature. The same mechanism is applied to the reaction time.

The main reaction temperature range of the invention is medium temperature, which tends to form a rough layered carbon layer, which has a certain barrier effect on the deflection and the expansion of cracks, and further has a certain contribution to the improvement of the plasticity of the material, so that the carbon felt has good mechanical strength, and the carbon felt with moderate densification is obtained by controlling the deposition time, so that the carbon felt has good heat insulation performance.

Preferably, the temperature is raised to 800-1200 ℃ at a temperature raising rate of 1-10 ℃/min.

Preferably, the hydrocarbon gas is any one or a mixture of natural gas, liquefied petroleum gas, methane, propylene and propane; the flow rate of the hydrocarbon gas is 50-100 sccm.

The high-temperature-resistant heat-insulating carbon felt prepared by the preparation method.

Has the advantages that: the high-temperature-resistant heat-insulating carbon felt prepared by the method has small volume density of 0.04-0.18g/cm3, heat conductivity coefficient of 0.05-0.3W/(m.K), carbon content of more than or equal to 99.5 percent and ash content of less than or equal to 0.1 percent.

The high-temperature-resistant heat-insulating carbon felt prepared by the preparation method is applied to heat preservation and heat insulation of a heat preservation furnace.

Has the advantages that: the high-temperature-resistant heat-insulating carbon felt prepared by the method has small volume density, low heat conductivity coefficient, excellent chemical corrosion resistance, compression resistance, impact resistance and mechanical property, can be used in various heat-insulating fields, and particularly can be used as a heat-insulating material in heat-insulating furnaces in various fields.

The invention has the advantages that: the polymer foam is carbonized to prepare the prefabricated soft carbon felt, the preparation process is simple, and the production cost is low. When the polymer foam is melamine foam, the melamine foam is porous and light.

The deposited pyrolytic carbon refers to a process of depositing carbon materials on a substrate from gaseous hydrocarbons through a high-temperature pyrolysis reaction. After the prefabricated soft carbon felt is deposited with the pyrolytic carbon, the pyrolytic carbon layer coats the carbon grids of the prefabricated soft carbon felt, so that the deflection and the expansion of cracks are effectively hindered, the chemical corrosion resistance and the high temperature resistance of the prefabricated soft carbon felt are improved, the service life of the prefabricated soft carbon felt is prolonged, and the mechanical properties of the prefabricated soft carbon felt, such as compression resistance, impact resistance and the like, are further improved.

According to the invention, by adjusting the reaction conditions in the pyrolytic carbon deposition process, the pyrolytic carbon tends to form a rough layered carbon layer, so that the method has a certain effect of hindering the deflection and the expansion of cracks, and further has a certain contribution to the improvement of the plasticity of the material, so that the carbon felt has good mechanical strength, and by controlling the deposition time, the carbon felt with moderate densification is obtained, so that the carbon felt has good heat insulation performance.

The high-temperature-resistant heat-insulating carbon felt prepared by the method is soft, elastic and not easy to crack, has the volume density of 0.04-0.18g/cm3, the heat conductivity coefficient of 0.05-0.3W/(m.K), the carbon content of more than or equal to 99.5 percent and the ash content of less than or equal to 0.1 percent, and has the characteristics of good heat insulation, tearing resistance, good rebound resilience, convenient use, durability and the like, and has wider application range.

Due to the adoption of the method of the inventionThe prepared high-temperature-resistant heat-insulation heat-preservation carbon felt is small in volume density and low in heat conductivity coefficient, and has excellent high-temperature resistance, chemical corrosion resistance, compression resistance, impact resistance, mechanical property and high temperature resistance>3000 ℃; chemical resistance: weight gain in 1900 deg.C silicon vapor environment for 2 hr<0.002g/cm²Carbon fiber weight gain under the same conditions>0.03g/cm²(ii) a The compression resistance can be adjusted according to the requirement>1Mpa can be used in various heat preservation fields, and especially can be used as a heat preservation material in heat preservation furnaces in various fields.

Drawings

Fig. 1 is an SEM image of a pyrolytic carbon layer in a high temperature resistant thermal insulation carbon felt prepared in example 1 of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are some embodiments of the present invention, but not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Test materials, reagents and the like used in the following examples are commercially available unless otherwise specified.

The specific techniques or conditions not specified in the examples can be performed according to the techniques or conditions described in the literature in the field or according to the product specification.

Example 1

The preparation method of the high-temperature-resistant heat-insulation heat-preservation carbon felt specifically comprises the following steps:

1) carbonizing treatment: the density is 0.008g/cm³And melamine foam with the thickness of 3cm is laid on a tool and then placed in a carbonization furnace, under the argon atmosphere, the carbonization furnace is quickly heated to 200 ℃ at the heating rate of 10 ℃/min and is kept at the constant temperature for 15min, then the temperature is heated to 350 ℃ at the heating rate of 0.2 ℃/min and is kept at the constant temperature for 30min, and then the heating rate of 5 ℃/min is usedAnd heating to 750 ℃, keeping the temperature for 30min, heating to 950 ℃ at the heating rate of 1 ℃/min, keeping the temperature for 15min, heating to 1200 ℃ at the heating rate of 5 ℃/min, keeping the temperature for 120min, and cooling to room temperature along with the furnace to obtain the prefabricated soft carbon felt.

2) Depositing pyrolytic carbon: and (3) placing the prefabricated soft carbon felt obtained after carbonization in a chemical vapor deposition furnace, rapidly heating the chemical vapor deposition furnace to 300 ℃ in a vacuum state, keeping the temperature for 30min, heating to 980 ℃ at a heating rate of 5 ℃/min, keeping the temperature for 30min, introducing nitrogen to the vacuum pressure of 1kPa, introducing propylene gas at a flow rate of 50sccm to start to deposit pyrolytic carbon, stopping introducing the propylene gas after 20min, vacuumizing, and freely cooling to below 300 ℃ to obtain the pyrolytic carbon.

The volume density of the thermal insulation carbon felt prepared by the embodiment is 0.04g/cm³The heat conductivity coefficient is 0.3W/(m.K), the carbon content is 99.9 percent, and the ash content is 0.01 percent; an SEM image of a pyrolytic carbon layer in the heat preservation carbon felt is shown in figure 1, and it can be seen that pyrolytic carbon enters the inside of the carbon felt and coats the carbon grids of the prefabricated soft carbon felt.

Example 2

The preparation method of the high-temperature-resistant heat-insulation heat-preservation carbon felt specifically comprises the following steps:

1) carbonizing treatment: the density is 0.01g/cm³And melamine foam with the thickness of 3cm is laid on a tool and then is placed in a carbonization furnace for carbonization, the carbonization furnace is quickly heated to 250 ℃ at the heating rate of 10 ℃/min under the argon atmosphere, the temperature is kept for 30min, then the temperature is raised to 350 ℃ at the heating rate of 0.5 ℃/min, the temperature is kept for 60min, then the temperature is raised to 700 ℃ at the heating rate of 5 ℃/min, the temperature is kept for 60min, then the temperature is raised to 900 ℃ at the heating rate of 0.2 ℃/min, the temperature is kept for 30min, then the temperature is raised to 1000 ℃ at the heating rate of 5 ℃/min, the temperature is kept for 120min, and then the furnace is cooled to the room temperature to obtain the prefabricated soft carbon felt.

2) Depositing pyrolytic carbon: and (2) placing the prefabricated soft carbon felt obtained after carbonization in a chemical vapor deposition furnace, rapidly heating the chemical vapor deposition furnace to 300 ℃ in a vacuum state, keeping the temperature for 30min, then heating to 800 ℃ at a heating rate of 5 ℃/min, keeping the temperature for 60min, introducing nitrogen to the vacuum pressure of 1kPa, introducing liquefied petroleum gas at a flow rate of 60sccm to start to deposit pyrolytic carbon, stopping introducing the liquefied petroleum gas after 10min, vacuumizing, and freely cooling to below 300 ℃ to obtain the pyrolytic carbon.

The volume density of the thermal insulation carbon felt prepared by the embodiment is 0.12g/cm³The thermal conductivity coefficient is 0.25W/(m.K), the carbon content is 99.6%, and the ash content is 0.05%.

Example 3

The preparation method of the high-temperature-resistant heat-insulation heat-preservation carbon felt specifically comprises the following steps:

1) carbonizing treatment: the density is 0.01g/cm³And melamine foam with the thickness of 3cm is laid on a tool and then is placed in a carbonization furnace for carbonization, the carbonization furnace is quickly heated to 250 ℃ at the heating rate of 10 ℃/min and is kept at the constant temperature for 60min under the argon atmosphere, then the temperature is heated to 400 ℃ at the heating rate of 0.2 ℃/min and is kept at the constant temperature for 120min, then the temperature is heated to 700 ℃ at the heating rate of 1 ℃/min and is kept at the constant temperature for 120min, then the temperature is heated to 950 ℃ at the heating rate of 0.2 ℃/min and is kept at the constant temperature for 60min, then the temperature is heated to 1200 ℃ at the heating rate of 1 ℃/min and is kept at the constant temperature for 120min and then is cooled to the room temperature along with the furnace, and the prefabricated soft carbon felt is obtained.

2) Depositing pyrolytic carbon: and (3) placing the prefabricated soft carbon felt obtained after carbonization in a chemical vapor deposition furnace, rapidly heating the chemical vapor deposition furnace to 300 ℃ in a vacuum state, keeping the temperature for 60min, then heating to 1050 ℃ at a heating rate of 1 ℃/min, keeping the temperature for 60min, introducing inert gas to vacuum pressure of 1kPa, introducing propane at a flow rate of 80sccm to start deposition of pyrolytic carbon, keeping the flow rate constant for 60min, stopping introduction of propane, vacuumizing, and freely cooling to below 300 ℃ to obtain the pyrolytic carbon.

The volume density of the thermal insulation carbon felt prepared by the embodiment is 0.14g/cm³The thermal conductivity coefficient is 0.21W/(m.K), the carbon content is 99.9%, and the ash content is 0.01%.

Example 4

The preparation method of the high-temperature-resistant heat-insulation heat-preservation carbon felt specifically comprises the following steps:

1) carbonizing treatment: the density is 0.01g/cm³And melamine foam with the thickness of 3cm is laid on a tool and then is put in a carbonization furnace for carbonization, and the carbonization furnace is firstly heated to 10 ℃ under the argon atmosphereAnd (3) rapidly heating to 250 ℃ at a heating rate of/min, keeping the temperature for 40min, heating to 400 ℃ at a heating rate of 0.2 ℃/min, keeping the temperature for 100min, heating to 700 ℃ at a heating rate of 1 ℃/min, keeping the temperature for 100min, heating to 950 ℃ at a heating rate of 0.2 ℃/min, keeping the temperature for 60min, heating to 1200 ℃ at a heating rate of 1 ℃/min, keeping the temperature for 120min, and cooling to room temperature along with the furnace to obtain the prefabricated soft carbon felt.

2) Depositing pyrolytic carbon: and (3) placing the prefabricated soft carbon felt obtained after carbonization in a chemical vapor deposition furnace, rapidly heating the chemical vapor deposition furnace to 300 ℃ in a vacuum state, keeping the temperature for 60min, then heating to 1100 ℃ at the heating rate of 1 ℃/min, keeping the temperature for 60min, introducing inert gas to the vacuum pressure of 1kPa, introducing propane at the gas flow of 80sccm to start deposition of pyrolytic carbon, keeping the flow for 60min, stopping introducing propane, vacuumizing, and freely cooling to below 300 ℃ to obtain the pyrolytic carbon.

The volume density of the thermal insulation carbon felt prepared by the embodiment is 0.15g/cm³The thermal conductivity coefficient is 0.18W/(m.K), the carbon content is 99.7%, and the ash content is 0.01%.

Example 5

The preparation method of the high-temperature-resistant heat-insulation heat-preservation carbon felt specifically comprises the following steps:

1) carbonizing treatment: the density is 0.01g/cm³And melamine foam with the thickness of 3cm is laid on a tool and then is placed in a carbonization furnace for carbonization, the carbonization furnace is quickly heated to 200 ℃ at the heating rate of 10 ℃/min and is kept at the constant temperature for 60min under the argon atmosphere, then the temperature is heated to 350 ℃ at the heating rate of 1 ℃/min and is kept at the constant temperature for 50min, then the temperature is heated to 700 ℃ at the heating rate of 1 ℃/min and is kept at the constant temperature for 60min, then the temperature is heated to 950 ℃ at the heating rate of 0.2 ℃/min and is kept at the constant temperature for 40min, then the temperature is heated to 1000 ℃ at the heating rate of 1 ℃/min and is kept at the constant temperature for 120min, and then the furnace is cooled to room temperature to obtain the prefabricated soft carbon felt.

2) Depositing pyrolytic carbon: and (3) placing the prefabricated soft carbon felt obtained after carbonization in a chemical vapor deposition furnace, rapidly heating the chemical vapor deposition furnace to 300 ℃ in a vacuum state, keeping the temperature for 60min, then heating to 1200 ℃ at the heating rate of 1 ℃/min, keeping the temperature for 60min, introducing inert gas to the vacuum pressure of 1kPa, introducing propane at the gas flow of 100sccm to start deposition of pyrolytic carbon, keeping the flow for 60min, stopping introducing propane, vacuumizing, and freely cooling to below 300 ℃ to obtain the pyrolytic carbon.

The volume density of the thermal insulation carbon felt prepared by the embodiment is 0.18g/cm³The thermal conductivity coefficient is 0.08W/(m.K), the carbon content is 99.6%, and the ash content is 0.02%.

Example 6

The preparation method of the high-temperature-resistant heat-insulation heat-preservation carbon felt specifically comprises the following steps:

1) carbonizing treatment: the density is 0.01g/cm³And melamine foam with the thickness of 3cm is laid on a tool and then is placed in a carbonization furnace for carbonization, the carbonization furnace is quickly heated to 200 ℃ at the heating rate of 10 ℃/min and is kept at the constant temperature for 60min under the argon atmosphere, then the temperature is heated to 350 ℃ at the heating rate of 1 ℃/min and is kept at the constant temperature for 50min, then the temperature is heated to 750 ℃ at the heating rate of 1 ℃/min and is kept at the constant temperature for 60min, then the temperature is heated to 950 ℃ at the heating rate of 0.2 ℃/min and is kept at the constant temperature for 50min, then the temperature is heated to 1100 ℃ at the heating rate of 1 ℃/min and is kept at the constant temperature for 120min, and then the furnace is cooled to room temperature to obtain the prefabricated soft carbon felt.

2) Depositing pyrolytic carbon: and (3) placing the prefabricated soft carbon felt obtained after carbonization in a chemical vapor deposition furnace, rapidly heating the chemical vapor deposition furnace to 500 ℃ in a vacuum state, keeping the temperature for 60min, then heating to 1200 ℃ at the heating rate of 1 ℃/min, keeping the temperature for 60min, introducing inert gas to the vacuum pressure of 1kPa, introducing propane at the gas flow of 100sccm to start deposition of pyrolytic carbon, keeping the flow for 60min, stopping introducing propane, vacuumizing, and freely cooling to below 300 ℃ to obtain the pyrolytic carbon.

The volume density of the thermal insulation carbon felt prepared by the embodiment is 0.18g/cm³The thermal conductivity coefficient is 0.1W/(m.K), the carbon content is 99.6%, and the ash content is 0.03%.

The above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.