阅读说明：本技术 一种高强度气凝胶改性的隔热毡及其制备方法 (High-strength aerogel modified heat insulation felt and preparation method thereof ) 是由 张鑫扬 张昭 张锦文 于 2020-12-28 设计创作，主要内容包括：本发明公开了一种高强度气凝胶改性的隔热毡,包括硅酸铝纤维毡基材,依次设置在所述硅酸铝纤维毡基材上的聚酰胺纳米纤维/碳纳米管复合凝胶涂层、硅气凝胶改性的氟碳树脂涂层；所述聚酰胺纳米纤维/碳纳米管纤维复合凝胶涂层中,聚酰胺纳米纤维、碳纳米管的质量比为7：(1-3)；所述硅气凝胶改性的氟碳树脂涂层包括聚合物改性的纳米二氧化硅气凝胶、氟碳树脂、助剂。本发明还公开了该高强度气凝胶改性的隔热毡的制备方法。本发明制得的隔热毡不仅隔热性能好,且机械性能优异,具有一定的自清洁性能。(The invention discloses a high-strength aerogel modified heat insulation felt which comprises an aluminum silicate fiber felt base material, a polyamide nanofiber/carbon nanotube composite gel coating and a silicon aerogel modified fluorocarbon resin coating, wherein the polyamide nanofiber/carbon nanotube composite gel coating and the silicon aerogel modified fluorocarbon resin coating are sequentially arranged on the aluminum silicate fiber felt base material; in the polyamide nanofiber/carbon nanotube fiber composite gel coating, the mass ratio of the polyamide nanofiber to the carbon nanotube is 7: (1-3); the silicon aerogel modified fluorocarbon resin coating comprises polymer modified nano silicon dioxide aerogel, fluorocarbon resin and an auxiliary agent. The invention also discloses a preparation method of the high-strength aerogel modified heat insulation felt. The heat insulation felt prepared by the invention has good heat insulation performance, excellent mechanical performance and certain self-cleaning performance.)

1. The utility model provides a thermal-insulated felt of high strength aerogel modification which characterized in that: the silicon aerogel composite gel coating comprises an aluminum silicate fiber felt base material, and a polyamide nanofiber/carbon nanotube composite gel coating and a silicon aerogel modified fluorocarbon resin coating which are sequentially arranged on the aluminum silicate fiber felt base material; in the polyamide nanofiber/carbon nanotube fiber composite gel coating, the mass ratio of the polyamide nanofiber to the carbon nanotube is 7: (1-3); the silicon aerogel modified fluorocarbon resin coating comprises polymer modified nano silicon dioxide aerogel, fluorocarbon resin and an auxiliary agent.

2. The high strength aerogel modified insulation blanket of claim 1, wherein: the auxiliary agent is a defoaming agent, a film forming auxiliary agent, a thickening agent and a flatting agent.

3. The high strength aerogel modified insulation blanket of claim 2, wherein: the silicon aerogel modified fluorocarbon resin coating comprises, by weight, 2-5 parts of polymer modified silicon dioxide aerogel, 30-40 parts of fluorocarbon resin, 0.1-0.5 part of defoaming agent, 1-2 parts of film forming additive, 0.1-0.2 part of thickening agent and 0.1-0.2 part of flatting agent.

4. The high strength aerogel modified insulation blanket of claim 1, wherein: the fluorocarbon resin is one of polytetrafluoroethylene resin and polyvinylidene fluoride resin.

5. The method of preparing a high strength aerogel modified insulation blanket according to any of claims 1 to 4, comprising the steps of:

(1) dispersing polyamide nano-fibers in a mixed solvent of water and tert-butyl alcohol to prepare a polyamide nano-fiber dispersion liquid with the mass concentration of 1-2%; dispersing the carbon nano tube in a mixed solvent of water and tertiary butanol to prepare a carbon nano tube dispersion liquid with the mass concentration of 0.8-1.5%; mixing the polyamide nanofiber dispersion liquid and the carbon nanotube dispersion liquid, and then carrying out ultrasonic treatment to prepare a mixed dispersion liquid;

(2) placing the aluminum silicate fiber felt into the mixed dispersion liquid for dipping treatment, taking out the aluminum silicate fiber felt for freeze drying treatment, and obtaining the aluminum silicate fiber felt modified by the polyamide nanofiber/carbon nanotube aerogel coating;

(3) dispersing nano-silica aerogel powder in deionized water to obtain nano-silica aerogel dispersion liquid, dispersing acrylamide monomers in deionized water, adding the prepared nano-silica aerogel dispersion liquid, sodium dodecyl benzene sulfonate and N, N-methylene bisacrylamide, uniformly mixing, adding an initiator, heating for reaction, filtering after the reaction is finished, and drying the solid to obtain polymer modified nano-silica aerogel;

(4) and (3) uniformly mixing and stirring fluorocarbon resin, polymer modified silicon dioxide aerogel, an auxiliary agent and deionized water to prepare mixed slurry, then placing the polyamide nanofiber/carbon nanotube aerogel coating modified aluminum silicate fiber felt prepared in the step (2) into the mixed slurry, performing impregnation treatment, and then performing heat preservation treatment to obtain the high-strength aerogel modified heat insulation felt.

6. The method of claim 5, wherein the method comprises the steps of: in the step (1), the volume ratio of water to tert-butyl alcohol in the mixed solvent is 3: (1-2).

7. The method of claim 5, wherein the method comprises the steps of: in the step (2), the dosage ratio of the aluminum silicate fiber felt to the mixed dispersion liquid is (5-7) g: 100 ml.

8. The method of claim 5, wherein the method comprises the steps of: in the step (3), the temperature-raising reaction conditions are as follows: the reaction time is 1-2h at 70-90 ℃.

9. The method of claim 5, wherein the method comprises the steps of: in the step (3), the dosage of each component is as follows by weight: 3-7 parts of nano silicon dioxide aerogel powder, 20-40 parts of acrylamide monomer, 0.01-0.05 part of sodium dodecyl benzene sulfonate, 0.01-0.02 part of N, N-methylene bisacrylamide and 0.1-0.2 part of initiator.

10. The method of claim 5, wherein the method comprises the steps of: in the step (4), the heat preservation treatment conditions are as follows: firstly, heat preservation treatment is carried out for 1-2h at 60-70 ℃, then the temperature is raised to 100 ℃ at the speed of 1 ℃/min, heat preservation treatment is carried out for 30-60min, finally the temperature is raised to 120 ℃ at the speed of 0.5 ℃/min, and heat preservation treatment is carried out for 1-2 h.

Technical Field

The invention relates to the field of heat insulation materials, in particular to a high-strength aerogel modified heat insulation felt and a preparation method thereof.

Background

With the rapid development of the technological level, various heat-insulating materials are continuously pushed out and new, and modern heat-insulating materials are widely applied to equipment pipelines of petroleum, chemical engineering, smelting and electric power departments and industrial and civil buildings due to good heat-insulating and energy-saving performance of the modern heat-insulating materials, but also put higher requirements on a high-temperature heat-insulating system, have higher thermal efficiency, improve the utilization rate of effective heat, reduce waste heat output, and have a series of performances of high temperature resistance, light weight, high efficiency, high stability and the like; while still providing a good working environment for the workers.

According to the property of the heat insulating material, the heat insulating material can be divided into three categories: organic, inorganic, and metal interlayers. The high-temperature heat insulation aspect commonly used at present mainly comprises inorganic materials, such as aluminum silicate fibers, rock wool, glass wool, expanded perlite, perlite bricks, foam concrete and the like. The fiber-based heat insulating material, one of the most important types of heat insulating materials, has the advantages of low density, soft texture, high strength, easy processing and forming and the like. Common fibrous thermal insulation materials include asbestos, aluminum silicate fibers, glass ceramic fibers, alumina fibers, high silica fibers, and the like. These insulation fibers can now be produced in large quantities and meet the requirements of different temperatures. The refractory alumina silicate fiber, also called ceramic fiber, is an inorganic material prepared by selecting proper process treatment, using high-quality flint clay, silicon dioxide, high-purity alumina, zircon sand and the like as raw materials, and performing fusion blowing or throwing in a resistance furnace to polymerize and fiberize dispersed materials with the same chemical composition and structure and different chemical compositions.

SiO₂The aerogel is a novel solid with low density, nano-porous and amorphous state and a continuous three-dimensional network structure, the network diameter is 1-100 nm, and the aerogel belongs to a typical mesoporous material. Owing to their particularly porous nature, are frequently used for modifying adsorption, sound insulation and thermal insulation materials. Chinese patent CN201810528284.X discloses an aerogel heat-insulating felt prepared by supercritical drying of an organic solvent and a preparation method thereof, and relates to the technical field of dielectric materials, wherein the aerogel heat-insulating felt is mainly prepared by sequentially carrying out sol, gelling, aging and supercritical drying of the organic solvent on silica aerogel and reinforcing fibers; the silica aerogel comprises a silicon source, a hydrophilic modifier and shadingThe agent comprises silicon source of tetraethoxysilane, hydrophilic modifier of methyltriethoxysilane and opacifier of zirconium dioxide; the medium for supercritical drying of the organic solvent is one of alcohol, alkane and ketone. The aerogel heat insulation felt prepared by the invention maintains the excellent performance of the aerogel, improves the strength and heat resistance of the material, and overcomes the defects of poor mechanical strength, large brittleness and the like of the existing aerogel material. Although the prior art can prepare materials with good heat insulation performance, the preparation process is complex, the requirement on equipment is high, and the mechanical property of the prepared heat insulation felt needs to be further improved.

Disclosure of Invention

One of the technical problems to be solved by the invention is as follows: aiming at the defects in the prior art, the high-strength aerogel modified heat insulation felt is provided, an aluminum silicate fiber felt is used as a base material, and a polyamide nanofiber/carbon nanotube composite gel coating and a silicon aerogel modified fluorocarbon resin coating are sequentially arranged on the surface of the aluminum silicate fiber felt, so that the heat insulation felt with multiple heat insulation functions is prepared. The heat insulation felt disclosed by the invention has a good heat insulation function, a certain self-cleaning function and good mechanical properties.

The second technical problem to be solved by the invention is to provide a preparation method of the high-strength aerogel modified heat insulation felt aiming at the defects of the prior art, the method is simple to operate, and the prepared heat insulation felt is excellent in heat insulation performance and good in mechanical property.

In order to solve the first technical problem, the technical scheme of the invention is as follows:

a high-strength aerogel modified heat insulation felt comprises an aluminum silicate fiber felt base material, and a polyamide nanofiber/carbon nanotube composite gel coating and a silicon aerogel modified fluorocarbon resin coating which are sequentially arranged on the aluminum silicate fiber felt base material; in the polyamide nanofiber/carbon nanotube fiber composite gel coating, the mass ratio of the polyamide nanofiber to the carbon nanotube is 7: (1-3); the silicon aerogel modified fluorocarbon resin coating comprises polymer modified nano silicon dioxide aerogel, fluorocarbon resin and an auxiliary agent.

Preferably, the auxiliary agent is a defoaming agent, a film forming auxiliary agent, a thickening agent and a leveling agent. Further, the defoaming agent is preferably a modified polysiloxane defoaming agent EFKA-2524; the film-forming auxiliary agent is preferably 3-methoxy-3-methyl-1-butanol; the thickener is preferably guar gum; the leveling agent is preferably an Effka EFKA-3888 leveling agent.

Preferably, the silicon aerogel modified fluorocarbon resin coating comprises, by weight, 2-5 parts of polymer modified silicon dioxide aerogel, 30-40 parts of fluorocarbon resin, 0.1-0.5 part of defoaming agent, 1-2 parts of film forming aid, 0.1-0.2 part of thickening agent and 0.1-0.2 part of leveling agent.

Preferably, in the above technical solution, the fluorocarbon resin is one of polytetrafluoroethylene resin and polyvinylidene fluoride resin.

In order to solve the second technical problem, the technical solution of the present invention is:

a preparation method of a high-strength aerogel modified heat insulation felt comprises the following steps:

(1) dispersing polyamide nano-fibers in a mixed solvent of water and tert-butyl alcohol to prepare a polyamide nano-fiber dispersion liquid with the mass concentration of 1-2%; dispersing the carbon nano tube in a mixed solvent of water and tertiary butanol to prepare a carbon nano tube dispersion liquid with the mass concentration of 0.8-1.5%; mixing the polyamide nanofiber dispersion liquid and the carbon nanotube dispersion liquid, and then carrying out ultrasonic treatment to prepare a mixed dispersion liquid;

(2) placing the aluminum silicate fiber felt into the mixed dispersion liquid for dipping treatment, taking out the aluminum silicate fiber felt for freeze drying treatment, and obtaining the aluminum silicate fiber felt modified by the polyamide nanofiber/carbon nanotube aerogel coating;

(3) dispersing nano-silica aerogel powder in deionized water to obtain nano-silica aerogel dispersion liquid, dispersing acrylamide monomers in deionized water, adding the prepared nano-silica aerogel dispersion liquid, sodium dodecyl benzene sulfonate and N, N-methylene bisacrylamide, uniformly mixing, adding an initiator, heating for reaction, filtering after the reaction is finished, and drying the solid to obtain polymer modified nano-silica aerogel;

(4) and (3) uniformly mixing and stirring fluorocarbon resin, polymer modified silicon dioxide aerogel, an auxiliary agent and deionized water to prepare mixed slurry, then placing the polyamide nanofiber/carbon nanotube aerogel coating modified aluminum silicate fiber felt prepared in the step (2) into the mixed slurry, performing impregnation treatment, and then performing heat preservation treatment to obtain the high-strength aerogel modified heat insulation felt.

Preferably, in the step (1), the volume ratio of water to tert-butanol in the mixed solvent is 3: (1-2).

Preferably, in the step (2), the usage ratio of the alumina silicate fiber mat to the mixed dispersion is (5-7) g: 100 ml.

As a preferable mode of the above-mentioned means, in the step (3), the temperature-increasing reaction conditions are: the reaction time is 1-2h at 70-90 ℃.

Preferably, in the step (3), the components are used in the following amounts by weight: 3-7 parts of nano silicon dioxide aerogel powder, 20-40 parts of acrylamide monomer, 0.01-0.05 part of sodium dodecyl benzene sulfonate, 0.01-0.02 part of N, N-methylene bisacrylamide and 0.1-0.2 part of initiator.

Preferably, in the step (4), the conditions of the heat-retaining treatment are as follows: firstly, heat preservation treatment is carried out for 1-2h at 60-70 ℃, then the temperature is raised to 100 ℃ at the speed of 1 ℃/min, heat preservation treatment is carried out for 30-60min, finally the temperature is raised to 120 ℃ at the speed of 0.5 ℃/min, and heat preservation treatment is carried out for 1-2 h.

Due to the adoption of the technical scheme, the invention has the beneficial effects that:

the high-strength aerogel modified heat insulation felt provided by the invention comprises an aluminum silicate fiber felt base material, and a polyamide nanofiber/carbon nanotube composite gel coating and a silicon aerogel modified fluorocarbon resin coating which are sequentially arranged on the aluminum silicate fiber felt base material. The polyamide nanofiber has good mechanical properties, the polyamide nanofiber dispersion liquid and the carbon nanotube dispersion liquid are mixed and used for modifying the aluminum silicate fiber felt matrix, the polyamide nanofiber and the carbon nanotube are mutually interpenetrated and crosslinked, and a 3D interconnected porous structure coating is formed after freeze drying, and the coating has good bonding performance with the aluminum silicate fiber felt matrix and good mechanical properties. And then the aluminum silicate fiber felt is placed in mixed slurry containing fluorocarbon resin for treatment, the treatment conditions are effectively controlled, the prepared fluorocarbon resin coating and the polyamide nanofiber/carbon nanotube composite aerogel coating have good combination performance, and the heat insulation performance and the mechanical property of the aluminum silicate fiber felt are effectively improved.

In the process of preparing the high-strength silicon aerogel modified heat insulation felt, firstly, the dispersion liquid of the polyamide nano fibers and the dispersion liquid of the carbon nano tubes are mixed, then, the mixture is self-assembled on the surface of the aluminum silicate fiber felt, the polyamide nano fibers and the carbon nano tubes are mutually interpenetrated and crosslinked, and after freeze drying treatment, the composite aerogel coating with the three-dimensional network structure is obtained. In order to better improve the performance of the heat insulation felt, the invention firstly adopts polyacrylamide to carry out in-situ modification on nano-silica aerogel to prepare polyacrylamide coated modified nano-silica aerogel, then the nano-silica aerogel is modified by fluorocarbon resin to obtain mixed slurry, the polyamide nano-fiber/carbon nano-tube composite aerogel coating modified aluminum silicate fiber felt is added, the dipping treatment and the staged heat preservation treatment are carried out, firstly, the mixed slurry at low temperature effectively permeates into the aluminum silicate fiber felt and is wetted with the polyamide nano-fiber/carbon nano-tube composite aerogel coating, then, the temperature is slowly raised, the heat preservation treatment is continued, the mixed slurry forms a certain polymer coating on the surface of the polyamide nano-fiber/carbon nano-tube composite aerogel coating, and finally, the temperature is continuously raised to remove the solvent, thus forming a compact coating. The heat insulation felt prepared by the invention has good heat insulation performance, excellent mechanical performance and certain self-cleaning performance.

Detailed Description

The invention is further illustrated by the following examples. It should be understood that these examples are for illustrative purposes only and are not intended to limit the scope of the present invention.

The raw material sources and performance parameters adopted in the invention are as follows:

polyamide nanofibers: is prepared by melt spinning of PA66 from Xinxiang nylon Co, wherein the diameter of the polyamide fiber is 100 +/-5 nm, and the length of the polyamide fiber is 2-6 mu m.

Carbon nanotube: average diameter of 2-10nm and average length of 1-5 μm, and is available from Nanjing Xiancheng nanomaterial science and technology Limited.

Aluminum silicate fiber felt: purchased from Shandong Luyang energy saving materials, Inc.

Polytetrafluoroethylene resin: the particle diameter is 650 mu m, the apparent density is 0.4-0.5g/ml, and the particle size is purchased from Jinheng plastics Co., Ltd.

Nano silica aerogel powder: the density is 0.08g/ml, the thermal conductivity coefficient is 0.018 +/-0.002W/m.k, and the material is purchased from Suzhou Tongxuan new material Co.

Modified polysiloxane defoamer EFKA-2524, available from Effca adjuvant, Inc. of the Netherlands.

Effka EFKA-3888 leveling agent: available from polymer materials, Inc. of Yitong, Guangzhou.

Example 1

(1) Dispersing 1g of polyamide nanofiber in a mixed solvent of 30ml of water and 20ml of tert-butyl alcohol to prepare a polyamide nanofiber dispersion liquid; dispersing 0.4g of carbon nano tube in a mixed solvent of 30ml of water and 20ml of tertiary butanol to prepare a carbon nano tube dispersion liquid; mixing the polyamide nanofiber dispersion liquid and the carbon nanotube dispersion liquid, and performing ultrasonic treatment for 30min at 500W to obtain a mixed dispersion liquid;

(2) soaking 10g of aluminum silicate fiber felt in 200ml of the mixed dispersion liquid for 2 hours, taking out the aluminum silicate fiber felt, and performing freeze drying treatment at the temperature of minus 5 ℃ for 20 hours to obtain the aluminum silicate fiber felt modified by the polyamide nanofiber/carbon nanotube aerogel coating;

(3) dispersing 3 parts of nano-silica aerogel powder in 50ml of deionized water to obtain nano-silica aerogel dispersion liquid, dispersing 20 parts of acrylamide monomer in 100ml of deionized water, adding the prepared nano-silica aerogel dispersion liquid, 0.01-part of sodium dodecyl benzene sulfonate and 0.01 part of N, N-methylene bisacrylamide, uniformly mixing, adding 0.1 part of initiator, reacting at 70 ℃ for 1 hour, filtering after the reaction is finished, and drying the solid to obtain polymer modified nano-silica aerogel;

(4) and (2) mixing and stirring 30 parts of polytetrafluoroethylene resin, 2 parts of polymer modified silica aerogel, 0.1 part of modified polysiloxane defoamer EFKA-2524, 1 part of 3-methoxy-3-methyl-1-butanol, 0.1 part of guar gum, 0.1 part of Effka EFKA-3888 flatting agent and 80 parts of deionized water uniformly to prepare mixed slurry, then placing the polyamide nanofiber/carbon nanotube aerogel coating modified aluminum silicate fiber felt prepared in the step (2) into the mixed slurry, soaking at normal temperature for 2 hours, then carrying out heat preservation treatment at 60 ℃ for 1 hour, then heating to 100 ℃ at the speed of 1 ℃/min, carrying out heat preservation treatment for 30min, finally heating to 120 ℃ at the speed of 0.5 ℃/min, and carrying out heat preservation treatment for 1 hour to obtain the high-strength aerogel modified heat insulation felt.

Example 2

(1) Dispersing 1g of polyamide nanofiber in a mixed solvent of 30ml of water and 20ml of tert-butyl alcohol to prepare a polyamide nanofiber dispersion liquid; dispersing 0.4g of carbon nano tube in a mixed solvent of 30ml of water and 20ml of tertiary butanol to prepare a carbon nano tube dispersion liquid; mixing the polyamide nanofiber dispersion liquid and the carbon nanotube dispersion liquid, and performing ultrasonic treatment for 30min at 500W to obtain a mixed dispersion liquid;

(2) soaking 14g of aluminum silicate fiber felt in 200ml of the mixed dispersion liquid for 3 hours, taking out the aluminum silicate fiber felt, and performing freeze drying treatment at the temperature of minus 5 ℃ for 20 hours to obtain the polyamide nanofiber/carbon nanotube aerogel coating modified aluminum silicate fiber felt;

(3) dispersing 7 parts of nano-silica aerogel powder in 50ml of deionized water to obtain nano-silica aerogel dispersion liquid, dispersing 40 parts of acrylamide monomer in 100ml of deionized water, adding the prepared nano-silica aerogel dispersion liquid, 0.05 part of sodium dodecyl benzene sulfonate and 0.02 part of N, N-methylene bisacrylamide, uniformly mixing, adding 0.2 part of initiator, reacting at 90 ℃ for 2 hours, filtering after the reaction is finished, and drying the solid to obtain polymer modified nano-silica aerogel;

(4) uniformly mixing and stirring 40 parts of polytetrafluoroethylene resin, 5 parts of polymer modified silicon dioxide aerogel, 0.5 part of modified polysiloxane defoamer EFKA-2524, 2 parts of 3-methoxy-3-methyl-1-butanol, 0.2 part of guar gum, 0.2 part of Effka EFKA-3888 flatting agent and 80 parts of deionized water to prepare mixed slurry, then placing the polyamide nanofiber/carbon nanotube aerogel coating modified aluminum silicate fiber felt prepared in the step (2) into the mixed slurry, soaking at normal temperature for 2 hours, then carrying out heat preservation treatment at 70 ℃ for 2 hours, then heating to 100 ℃ at the speed of 1 ℃/min, carrying out heat preservation treatment for 60 minutes, finally heating to 120 ℃ at the speed of 0.5 ℃/min, and carrying out heat preservation treatment for 2 hours to obtain the high-strength aerogel modified heat insulation felt.

Example 3

(1) Dispersing 1g of polyamide nanofiber in a mixed solvent of 30ml of water and 20ml of tert-butyl alcohol to prepare a polyamide nanofiber dispersion liquid; dispersing 0.4g of carbon nano tube in a mixed solvent of 30ml of water and 20ml of tertiary butanol to prepare a carbon nano tube dispersion liquid; mixing the polyamide nanofiber dispersion liquid and the carbon nanotube dispersion liquid, and performing ultrasonic treatment for 30min at 500W to obtain a mixed dispersion liquid;

(2) dipping 11g of aluminum silicate fiber felt in 200ml of the mixed dispersion liquid for 2 hours, taking out the aluminum silicate fiber felt, and carrying out freeze drying treatment at-5 ℃ for 20 hours to obtain the polyamide nanofiber/carbon nanotube aerogel coating modified aluminum silicate fiber felt;

(3) dispersing 4 parts of nano-silica aerogel powder in 50ml of deionized water to obtain nano-silica aerogel dispersion liquid, dispersing 30 parts of acrylamide monomer in 100ml of deionized water, adding the prepared nano-silica aerogel dispersion liquid, 0.02 part of sodium dodecyl benzene sulfonate and 0.01 part of N, N-methylene bisacrylamide, uniformly mixing, adding 0.1 part of initiator, reacting at 80 ℃ for 1 hour, filtering after the reaction is finished, and drying the solid to obtain polymer modified nano-silica aerogel;

(4) mixing and stirring uniformly 35 parts of polytetrafluoroethylene resin, 3 parts of polymer modified silicon dioxide aerogel, 0.2 part of modified polysiloxane defoamer EFKA-2524, 1.5 parts of 3-methoxy-3-methyl-1-butanol, 0.1 part of guar gum, 0.2 part of Effka EFKA-3888 flatting agent and 80 parts of deionized water to prepare mixed slurry, then placing the polyamide nanofiber/carbon nanotube aerogel coating modified aluminum silicate fiber felt prepared in the step (2) into the mixed slurry, soaking at normal temperature for 2 hours, then carrying out heat preservation treatment at 60 ℃ for 2 hours, then heating to 100 ℃ at the speed of 1 ℃/min, carrying out heat preservation treatment for 40min, finally heating to 120 ℃ at the speed of 0.5 ℃/min, and carrying out heat preservation treatment for 1 hour to obtain the high-strength aerogel modified heat insulation felt.

Example 4

(1) Dispersing 1g of polyamide nanofiber in a mixed solvent of 30ml of water and 20ml of tert-butyl alcohol to prepare a polyamide nanofiber dispersion liquid; dispersing 0.4g of carbon nano tube in a mixed solvent of 30ml of water and 20ml of tertiary butanol to prepare a carbon nano tube dispersion liquid; mixing the polyamide nanofiber dispersion liquid and the carbon nanotube dispersion liquid, and performing ultrasonic treatment for 30min at 500W to obtain a mixed dispersion liquid;

(2) dipping 13g of aluminum silicate fiber felt in 200ml of the mixed dispersion liquid for 3h, taking out the aluminum silicate fiber felt, and carrying out freeze drying treatment at-5 ℃ for 20h to obtain the polyamide nanofiber/carbon nanotube aerogel coating modified aluminum silicate fiber felt;

(3) dispersing 6 parts of nano-silica aerogel powder in 50ml of deionized water to obtain nano-silica aerogel dispersion liquid, dispersing 35 parts of acrylamide monomer in 100ml of deionized water, adding the prepared nano-silica aerogel dispersion liquid, 0.04 part of sodium dodecyl benzene sulfonate and 0.02 part of N, N-methylene bisacrylamide, uniformly mixing, adding 0.15 part of initiator, reacting at 80 ℃ for 2 hours, filtering after the reaction is finished, and drying the solid to obtain polymer modified nano-silica aerogel;

(4) mixing and stirring uniformly 35 parts of polytetrafluoroethylene resin, 4 parts of polymer modified silica aerogel, 0.4 part of modified polysiloxane defoamer EFKA-2524, 2 parts of 3-methoxy-3-methyl-1-butanol, 0.1 part of guar gum, 0.2 part of Effka EFKA-3888 flatting agent and 80 parts of deionized water to prepare mixed slurry, then placing the polyamide nanofiber/carbon nanotube aerogel coating modified aluminum silicate fiber felt prepared in the step (2) into the mixed slurry, soaking at normal temperature for 2 hours, then carrying out heat preservation treatment at 70 ℃ for 1 hour, then heating to 100 ℃ at the speed of 1 ℃/min, carrying out heat preservation treatment for 50min, finally heating to 120 ℃ at the speed of 0.5 ℃/min, and carrying out heat preservation treatment for 2 hours to obtain the high-strength aerogel modified heat insulation felt.

Comparative example 1

In the step (4), the polymer-modified silica aerogel was not added, and the other conditions were the same as in example 4.

Comparative example 2

The silica aerogel was not subjected to polymer modification, and the other conditions were the same as in example 4.

Comparative example 3

The polyamide fiber was modified without adding carbon nanotubes under the same conditions as in example 4.

The properties of the insulation blanket prepared as described above were tested.

1. Coefficient of thermal conductivity

Testing according to GB/T10294-2008. The thermal conductivity at room temperature was measured by means of a heat flow meter method (HFM 436, NETZSCH, Germany). 0.015

2. Tensile properties

The test is carried out by adopting the GB/T7911-2006 standard. 5.12

3. Contact Angle testing

And (3) measuring the waterproof performance of the heat insulation felt by adopting a CAM 200 contact angle tester.

The test results are shown in table 1.

TABLE 1

	Thermal conductivity, W/m.k	Tensile strength, MPa	Contact angle, ° c
				Example 1	0.018	5.12	155
Example 2	0.015	5.25	155
				Example 3	0.015	5.18	150
Example 4	0.017	5.15	152
				Comparative example 1	0.056	4.23	133
Comparative example 2	0.039	4.15	125
				Comparative example 3	0.035	3.95	120

The test results show that the heat insulation felt prepared by the invention has good heat insulation performance, and excellent waterproof performance and mechanical performance.

Further, it should be understood that various changes or modifications of the present invention may be made by those skilled in the art after reading the teaching of the present invention, and such equivalents may fall within the scope of the present invention as defined in the appended claims.