A water-repellent and heat-retaining fiber aerogel composite material and its preparation method

Abstract

The present invention discloses a water-repellent and heat-insulating fiber aerogel composite material in the field of aerogel technology and a preparation method thereof, comprising the following components in parts by weight: water-repellent and heat-insulating aerogel 13-18, a multilayer hydrophobic fiber net 53-76; the water-repellent and heat-insulating aerogel is a polyvinyl alcohol-cage silsesquioxane aerogel prepared from polyvinyl alcohol and vinyltrimethoxysilane; the multilayer hydrophobic fiber net is prepared from a hollow high-low temperature melting fiber with a skin-core structure and an ultra-fine polyester fiber. The present invention proposes to increase the aerogel particle loading by preparing a hollow skin-core two-component high-low temperature melting fiber, and the aerogel and hollow fiber fix the air, thereby achieving the technical effect of enhancing the warmth-insulating effect of the filler.

Description

Technical Field

[0001] The present invention belongs to the technical field of aerogels, and specifically relates to a water-repellent and heat-retaining fiber aerogel composite material and a preparation method thereof. Background Art

[0002] At present, the filling materials of better thermal insulation clothing on the market are mainly duck down, goose down and polyester fiber. The thermal insulation in extreme sports, military field and aerospace and other special environments requires high performance of the filling materials due to their special environment, such as wading, cold, humidity and other harsh environments. At present, the thermal insulation filling materials under such conditions are mainly Primasoft (abbreviated as P cotton) and 3M's Thinsulate high-efficiency thermal insulation fleece. Since its invention, aerogel has been widely used in various fields as an ideal thermal insulation material due to its extremely high porosity, extremely low density, high specific surface area and ultra-high pore volume rate. The previous application of aerogel in textile clothing and fibers has not been ideal. The current application in the clothing field is mainly based on nanopowders and aerogel fibers, but there is no effective and feasible solution for the use of nanoaerogel powder, and there are certain problems in recycling, resulting in waste of resources; another application is to add aerogel powder to synthetic fiber spinning masterbatch, but there has always been a contradiction: a small amount has poor thermal insulation effect, and a large amount makes spinning impossible; another method of use is to add aerogel to sponge or foam coating, such as the current Supai brand and Oros brand, but from the perspective of the thermal resistance of aerogel-filled sponge alone, the thermal resistance effect is not good.

[0003] The existing technology currently has the following main problems: the amount of aerogel used in the aerogel thermal insulation filler is low and the thermal insulation effect is poor. Summary of the Invention

[0004] In view of the above situation, in order to overcome the defects of the prior art, the present invention provides a water-repellent and thermal-insulating fiber aerogel composite material and a preparation method thereof. In order to solve the problem of low aerogel loading on thermal insulation fillers, the present invention proposes to prepare a hollow skin-core two-component high and low temperature melting fiber to achieve an increase in the aerogel particle loading capacity. The aerogel and hollow fibers fix the air, thereby achieving the technical effect of enhancing the thermal insulation effect of the filler.

[0005] In order to achieve the above-mentioned objectives, the technical solution adopted by the present invention is as follows: the present invention proposes a water-repellent and heat-insulating fiber aerogel composite material and a preparation method thereof, wherein the water-repellent and heat-insulating fiber aerogel composite material comprises the following components in parts by weight: 13-18 parts of water-repellent and heat-insulating aerogel and 53-76 parts of a multilayer hydrophobic fiber web; the water-repellent and heat-insulating aerogel is a polyvinyl alcohol-cage silsesquioxane aerogel prepared from polyvinyl alcohol and vinyltrimethoxysilane; the multilayer hydrophobic fiber web is prepared from a hollow high- and low-temperature melting fiber with a skin-core structure and an ultra-fine polyester fiber.

[0006] Preferably, the water-repellent and heat-insulating aerogel comprises the following components in parts by weight: 30-45 parts of polyvinyl alcohol and 5-7 parts of vinyltrimethoxysilane.

[0007] Preferably, the multi-layer hydrophobic fiber web comprises the following components in parts by weight: 21-39 parts of polyethylene terephthalate and 12-21 parts of polyethylene.

[0008] Preferably, the preparation method of the water-repellent thermal aerogel specifically comprises the following steps:

[0009] S1. Add vinyltrimethoxysilane to ethyl acetate and stir in a water bath to obtain a mixed solution;

[0010] S2, adding the hydrochloric acid solution dropwise to the mixed solution obtained in S1 until the pH is 4-5, stirring in a water bath to obtain a reaction solution, adding the ethanol solution to the reaction solution, filtering, washing with an ethanol solution having a mass concentration of 85-90% for 3 times, and drying to obtain a cage-type silsesquioxane;

[0011] S3, adding polyvinyl alcohol to deionized water, stirring in a water bath at 90° C. for 3 h to obtain a polyvinyl alcohol aqueous solution;

[0012] S4, adding the cage-type silsesquioxane obtained in S2 to the polyvinyl alcohol aqueous solution obtained in S3, and stirring at a speed of 1200-1300 rpm for 15-20 minutes to obtain a mixed solution;

[0013] S5. Add the mixed solution obtained in S4 into a mold and quickly freeze it with liquid nitrogen. After freezing, freeze-dry it at a vacuum degree of 10 Pa for 3 days to obtain a water-repellent and heat-retaining aerogel.

[0014] Preferably, in S1, the amount of vinyltrimethoxysilane added to ethyl acetate is 0.18-0.22 g / mL.

[0015] Preferably, in S1, the water bath temperature is 30-40°C, the stirring rate is 50-60 rpm, and the time is 10-15 min.

[0016] Preferably, in S2, the mass concentration of the hydrochloric acid solution is 18-20%.

[0017] Preferably, in S2, the water bath temperature is 30-35°C, the stirring rate is 60-80 rpm, and the time is 30-40 h.

[0018] Preferably, in S2, the ethanol concentration is 73-76%, and the amount added to the reaction solution is 1.2-1.4 g / mL.

[0019] Preferably, in S3, the amount of polyvinyl alcohol added to water is 0.1-0.12 g / mL.

[0020] Preferably, the method for preparing the multi-layer hydrophobic fiber web specifically comprises the following steps:

[0021] (1) Polyethylene terephthalate and polyethylene are sliced, and after feeding, pre-crystallization, and drying, they enter the screw extruder, pass through the pre-filter unit, and enter the two-component composite spinning machine through the distribution pipeline. Composite hollow spinning components are used for composite spinning to obtain polyester fiber / polyethylene composite hollow fibers with specifications of 2.8 dex and 3.8 mm;

[0022] (2) Polyethylene terephthalate is sliced, and after feeding, pre-crystallization, and drying, it enters the screw extruder, passes through the pre-filter unit, and enters the spinning machine through the distribution pipeline for composite spinning to obtain polyester fibers with specifications of 0.58-1.2dex and 38-50mm;

[0023] (3) The polyester fiber / polyethylene composite hollow fiber obtained in step (1) and the polyester fiber obtained in step (2) are opened separately using an opening machine, and blended using a blending machine at a mass ratio of 1:0.8-1.5. After being combed by a single-cylinder double-doffer carding machine, they are laid to obtain a multi-layer fiber web with a thickness of 0.5-3.5 cm and a square gram weight of 40-80 g.

[0024] The present invention also provides a method for preparing a water-repellent and heat-retaining fiber aerogel composite material, which specifically comprises the following steps:

[0025] The water-repellent and thermal-insulating aerogel is crushed into particles of 15-20 μm and placed in a powder box. A conveyor belt running at a speed of 10-20 m / s drives the multi-layer fiber web into the powder box. The aerogel particles are dispersed on the multi-layer fiber web, passed through a roller with a thickness of 2 / 3 of the multi-layer fiber web, and heated in a dryer at a temperature of 135-150°C. Subsequently, the aerogel is blown downward and drawn upward by a blower at a temperature of 10-15°C and a wind speed of 8-10 m / s to obtain a water-repellent and thermal-insulating fiber aerogel composite material.

[0026] The present invention has the following beneficial effects: hollow high-low temperature melting fibers having an outer layer of low-melting-point polyethylene and an inner core of high-melting-point hollow structure of polyethylene terephthalate are prepared by a spinning machine to load polyvinyl alcohol-cage silsesquioxane aerogel prepared by polyvinyl alcohol and vinyltrimethoxysilane; the outer layer is melted by heating to fix the aerogel particles on the fiber, and the polyester fiber structure is self-adhered to the fiber; the process does not require glue and is safe and environmentally friendly; the prepared cage silsesquioxane itself has double bonds and a hollow structure, which improves steric hindrance and can have flame retardant and hydrophobic effects; the organic polymer-silicon-based aerogel prepared by cage silsesquioxane and polyvinyl alcohol has the advantages of low density and high toughness; the nanoscale pore size is smaller than the free path of air molecules, which can restrict the free movement of gas molecules, making it difficult for gas molecules to collide with each other, reducing gas heat conduction and convection heat transfer; the materials used are non-toxic and harmless, safe and environmentally friendly; the prepared hollow fibers have hollow spaces inside to restrict heat conduction, and have the characteristics of warmth retention, fluffiness and lightweight. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 The results of the constant temperature heating table test of Examples 1-3 and Comparative Example 3 are shown;

[0028] Figure 2 This is a diagram showing the waterproof effect of Example 1;

[0029] Figure 3 This is the result diagram of the waterproof effect of Comparative Example 1;

[0030] Figure 4 This is a diagram showing the results of microscopic observation of Example 1.

[0031] The accompanying drawings are used to provide further understanding of the present invention and constitute a part of the specification. They are used to explain the present invention together with the embodiments of the present invention and do not constitute a limitation of the present invention. DETAILED DESCRIPTION

[0032] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments; based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meanings as those familiar to those skilled in the art. Furthermore, any methods and materials similar or equivalent to those described herein can be applied to the present invention. The preferred embodiments and materials described herein are for illustrative purposes only and are not intended to limit the scope of this application.

[0034] The experimental methods in the following examples, unless otherwise specified, are conventional methods; the test materials and test strains used in the following examples, unless otherwise specified, are purchased from commercial channels.

[0035] Example 1

[0036] A water-repellent and heat-insulating fiber aerogel composite material comprises the following components in parts by weight: 18 parts of water-repellent and heat-insulating aerogel and 76 parts of a multi-layer hydrophobic fiber web.

[0037] The water-repellent and heat-insulating aerogel comprises the following components in parts by weight: 45 parts of polyvinyl alcohol and 7 parts of vinyltrimethoxysilane.

[0038] The multi-layer hydrophobic fiber web includes the following components in parts by weight: 39 parts of polyethylene terephthalate and 21 parts of polyethylene.

[0039] The preparation method of the water-repellent thermal aerogel specifically comprises the following steps:

[0040] S1. Add 0.22 g / mL of vinyltrimethoxysilane to ethyl acetate, and stir at 60 rpm in a 40° C. water bath for 15 min to obtain a mixed solution.

[0041] S2, adding a 20% hydrochloric acid solution dropwise to the mixed solution obtained in S1 until the pH reaches 5, stirring at a rate of 80 rpm in a 35°C water bath for 40 h to obtain a reaction solution, adding a 76% ethanol solution at an addition amount of 1.4 g / mL to the reaction solution, filtering, washing three times with a 90% ethanol solution, and drying to obtain a cage-type silsesquioxane;

[0042] S3, adding polyvinyl alcohol in an amount of 0.12 g / mL to deionized water, stirring at 90° C. for 3 h to obtain a polyvinyl alcohol aqueous solution;

[0043] S4, adding the cage-type silsesquioxane obtained in S2 to the polyvinyl alcohol aqueous solution obtained in S3, and stirring at a speed of 1300 rpm for 20 minutes to obtain a mixed solution;

[0044] S5. Add the mixed solution obtained in S4 into a mold and quickly freeze it with liquid nitrogen. After freezing, freeze-dry it at a vacuum degree of 10 Pa for 3 days to obtain a water-repellent and heat-retaining aerogel.

[0045] The preparation method of the multi-layer hydrophobic fiber web specifically comprises the following steps:

[0046] (1) Polyethylene terephthalate and polyethylene are sliced, and after feeding, pre-crystallization, and drying, they enter the screw extruder, pass through the pre-filter unit, and enter the two-component composite spinning machine through the distribution pipeline. Composite hollow spinning components are used for composite spinning to obtain polyester fiber / polyethylene composite hollow fibers with specifications of 2.8 dex and 3.8 mm;

[0047] (2) Polyethylene terephthalate is sliced, and after feeding, pre-crystallization, and drying, it enters the screw extruder, passes through the pre-filter unit, and enters the spinning machine through the distribution pipeline for composite spinning to obtain polyester fibers with specifications of 1.2 dex and 38-50 mm;

[0048] (3) The polyester fiber / polyethylene composite hollow fiber obtained in step (1) and the polyester fiber obtained in step (2) were opened separately using an opening machine, and blended using a blending machine at a mass ratio of 1:1.5. After being combed by a single-cylinder double-doffer carding machine, they were laid to obtain a multi-layer fiber web with a thickness of 3.5 cm and a square gram weight of 80 g.

[0049] The present invention also provides a method for preparing a water-repellent and heat-retaining fiber aerogel composite material, which specifically comprises the following steps:

[0050] The water-repellent and thermal-insulating aerogel is crushed into 20um particles and placed in a powder box. A conveyor belt running at a speed of 20m / s drives the multi-layer fiber web into the powder box. The aerogel particles are dispersed on the multi-layer fiber web, passed through a roller with a thickness of 2 / 3 of the multi-layer fiber web, and heated in a dryer at a temperature of 150°C. Subsequently, the particles are blown downward and drawn upward by a blower at a temperature of 15°C and a wind speed of 10m / s to obtain a water-repellent and thermal-insulating fiber aerogel composite material.

[0051] Example 2

[0052] A water-repellent and heat-retaining fiber aerogel composite material comprises the following components in parts by weight: 13 parts of water-repellent and heat-retaining aerogel and 53 parts of a multi-layer hydrophobic fiber web.

[0053] The water-repellent and heat-insulating aerogel comprises the following components in parts by weight: 30 parts of polyvinyl alcohol and 5 parts of vinyltrimethoxysilane.

[0054] The multi-layer hydrophobic fiber web includes the following components in parts by weight: 21 parts of polyethylene terephthalate and 12 parts of polyethylene.

[0055] The preparation method of the water-repellent thermal aerogel specifically comprises the following steps:

[0056] S1. Add 0.18 g / mL of vinyltrimethoxysilane to ethyl acetate, and stir at 50 rpm in a 30°C water bath for 10 min to obtain a mixed solution.

[0057] S2, adding 18% hydrochloric acid solution dropwise to the mixed solution obtained in S1 until the pH reaches 4, stirring at a rate of 60 rpm in a 30°C water bath for 30 h to obtain a reaction solution, adding 73% ethanol solution at an addition amount of 1.2 g / mL to the reaction solution, filtering, washing three times with 85% ethanol solution, and drying to obtain cage-type silsesquioxane;

[0058] S3, adding polyvinyl alcohol in an amount of 0.1 g / mL to deionized water, stirring at 90° C. for 3 h to obtain a polyvinyl alcohol aqueous solution;

[0059] S4, adding the cage-type silsesquioxane obtained in S2 to the polyvinyl alcohol aqueous solution obtained in S3, and stirring at a speed of 1200 rpm for 15 minutes to obtain a mixed solution;

[0060] S5. Add the mixed solution obtained in S4 into a mold and quickly freeze it with liquid nitrogen. After freezing, freeze-dry it at a vacuum degree of 10 Pa for 3 days to obtain a water-repellent and heat-retaining aerogel.

[0061] The preparation method of the multi-layer hydrophobic fiber web specifically comprises the following steps:

[0062] (1) Polyethylene terephthalate and polyethylene are sliced, and after feeding, pre-crystallization, and drying, they enter the screw extruder, pass through the pre-filter unit, and enter the two-component composite spinning machine through the distribution pipeline. Composite hollow spinning components are used for composite spinning to obtain polyester fiber / polyethylene composite hollow fibers with specifications of 2.8 dex and 3.8 mm;

[0063] (2) Polyethylene terephthalate is sliced, and after feeding, pre-crystallization, and drying, it enters the screw extruder, passes through the pre-filter unit, and enters the spinning machine through the distribution pipeline for composite spinning to obtain polyester fibers with a specification of 0.58 dex and 38-50 mm;

[0064] (3) The polyester fiber / polyethylene composite hollow fiber obtained in step (1) and the polyester fiber obtained in step (2) were opened separately using an opening machine, and blended using a blending machine at a mass ratio of 1:0.8. After being combed by a single-cylinder double-doffer carding machine, they were laid to obtain a multi-layer fiber web with a thickness of 0.5 cm and a square gram weight of 40 g.

[0065] The present invention also provides a method for preparing a water-repellent and heat-retaining fiber aerogel composite material, which specifically comprises the following steps:

[0066] The water-repellent and thermal-insulating aerogel is crushed into 15um particles and placed in a powder box. A conveyor belt running at a speed of 10m / s drives the multi-layer fiber web into the powder box. The aerogel particles are dispersed on the multi-layer fiber web, passed through a roller with a thickness of 2 / 3 of the multi-layer fiber web, and heated in a dryer at a temperature of 135°C. Subsequently, the particles are blown downward and drawn upward by a blower at a temperature of 10°C and a wind speed of 8m / s to obtain a water-repellent and thermal-insulating fiber aerogel composite material.

[0067] Example 3

[0068] A water-repellent and heat-insulating fiber aerogel composite material comprises the following components in parts by weight: 16 parts of water-repellent and heat-insulating aerogel and 67 parts of a multi-layer hydrophobic fiber web.

[0069] The water-repellent and heat-insulating aerogel comprises the following components in parts by weight: 33 parts of polyvinyl alcohol and 6 parts of vinyltrimethoxysilane.

[0070] The multi-layer hydrophobic fiber web includes the following components in parts by weight: 23 parts of polyethylene terephthalate and 15 parts of polyethylene.

[0071] The preparation method of the water-repellent thermal aerogel specifically comprises the following steps:

[0072] S1. Add 0.2 g / mL of vinyltrimethoxysilane to ethyl acetate, and stir at 55 rpm in a 35°C water bath for 12 min to obtain a mixed solution.

[0073] S2, adding a 19% hydrochloric acid solution dropwise to the mixed solution obtained in S1 until the pH reaches 4.5, stirring at a rate of 70 rpm in a 32° C. water bath for 35 h to obtain a reaction solution, adding a 75% ethanol solution at an addition amount of 1.3 g / mL to the reaction solution, filtering, washing three times with an 86% ethanol solution, and drying to obtain a cage-type silsesquioxane;

[0074] S3, adding polyvinyl alcohol in an amount of 0.11 g / mL to deionized water, stirring at 90° C. for 3 h to obtain a polyvinyl alcohol aqueous solution;

[0075] S4, adding the cage-type silsesquioxane obtained in S2 to the polyvinyl alcohol aqueous solution obtained in S3, and stirring at a speed of 1250 rpm for 17 minutes to obtain a mixed solution;

[0076] S5. Add the mixed solution obtained in S4 into a mold and quickly freeze it with liquid nitrogen. After freezing, freeze-dry it at a vacuum degree of 10 Pa for 3 days to obtain a water-repellent and heat-retaining aerogel.

[0077] The preparation method of the multi-layer hydrophobic fiber web specifically comprises the following steps:

[0078] (1) Polyethylene terephthalate and polyethylene are sliced, and after feeding, pre-crystallization, and drying, they enter the screw extruder, pass through the pre-filter unit, and enter the two-component composite spinning machine through the distribution pipeline. Composite hollow spinning components are used for composite spinning to obtain polyester fiber / polyethylene composite hollow fibers with specifications of 2.8 dex and 3.8 mm;

[0079] (2) Polyethylene terephthalate is sliced, and after feeding, pre-crystallization, and drying, it enters the screw extruder, passes through the pre-filter unit, and enters the spinning machine through the distribution pipeline for composite spinning to obtain polyester fibers with a specification of 0.9 dex and 40 mm;

[0080] (3) The polyester fiber / polyethylene composite hollow fiber obtained in step (1) and the polyester fiber obtained in step (2) were opened separately using an opening machine, and blended using a blending machine at a mass ratio of 1:1.2. After being combed by a single-cylinder double-doffer carding machine, they were laid to obtain a multi-layer fiber web with a thickness of 2 cm and a square gram weight of 60 g.

[0081] The present invention also provides a method for preparing a water-repellent and heat-retaining fiber aerogel composite material, which specifically comprises the following steps:

[0082] The water-repellent and thermal-insulating aerogel is crushed into 17um particles and placed in a powder box. A conveyor belt running at a speed of 15m / s drives the multi-layer fiber web into the powder box. The aerogel particles are dispersed on the multi-layer fiber web, passed through a roller with a thickness of 2 / 3 of the multi-layer fiber web, and heated in a dryer at a temperature of 140°C. Subsequently, the particles are blown downward and drawn upward by a blower at a temperature of 13°C and a wind speed of 9m / s to obtain a water-repellent and thermal-insulating fiber aerogel composite material.

[0083] Comparative Example 1

[0084] This comparative example provides a thermal insulation material, Thinsulate produced by 3M Company of the United States.

[0085] Comparative Example 2

[0086] This comparative example provides a thermal insulation material, Primasoft from the United States.

[0087] Comparative Example 3

[0088] This comparative example provides a composite material, which differs from Example 1 only in that the composite material does not contain water-repellent thermal insulation aerogel, and the remaining components and component contents are the same as those in Example 1.

[0089] Experimental example

[0090] 1. In an open room temperature environment, the heating platform is kept at a constant temperature of 100°C. Example 1 and Comparative Examples 1-2 are placed on the platform respectively. The upper surface temperature of the fabric is observed by an infrared thermal imager to perform a constant temperature heating platform test.

[0091] 2. In an open room temperature environment, the heating platform is kept at a constant temperature of 100°C. Examples 1-3 and Comparative Example 3 are placed on the platform respectively. The upper surface temperature of the fabric is observed by an infrared thermal imager, and a constant temperature heating platform test is performed.

[0092] Result Analysis

[0093] Table 1 is a table showing the results of the constant temperature heating table test of Example 1 and Comparative Examples 1-2. As shown in the table, for the same heating time, the upper surface temperature of Example 1 is 43.2°C, and the upper surface temperatures of Comparative Examples 1-2 are 48.6°C and 49.1°C, respectively. The upper surface temperature of Example 1 is lower than that of Comparative Examples 1-2, indicating that the thermal insulation effect of Example 1 is better than that of Comparative Examples 1-2.

[0094] Table 1

[0095]

[0096] Table 2 is a table showing the results of thermal resistance testing of Example 1 and Thinsulatere produced by 3M Company. As shown in the table, the thermal resistance value of Example 1 is significantly higher than that of Thinsulatere produced by 3M Company, indicating that the thermal insulation effect of Example 1 is better than that of Thinsulatere produced by 3M Company.

[0097] Table 2

[0098]

[0099] Figure 1 This is a graph showing the results of the constant temperature heating table test of Examples 1-3 and Comparative Example 3. As shown in the figure, for the same heating time, the upper surface temperatures of Examples 1-3 are 43.2°C, 43.6°C, and 41.5°C, and the upper surface temperatures of Comparative Example 3 are 72.6°C, respectively. The upper surface temperature of Example 1 is significantly lower than that of Comparative Example 3, indicating that the thermal insulation effect of Examples 1-3 is better than that of Comparative Example 3, and the water-repellent and thermal-insulating aerogel can greatly improve the thermal insulation effect.

[0100] Figure 2 This is the result diagram of the waterproof effect of Example 1. Figure 3 This is a result diagram of the waterproof effect of comparative example 1. As shown in the figure, water forms water droplets on example 1 and enters the fiber gaps on comparative example 1, indicating that the waterproof effect of example 1 is better than that of comparative example 1.

[0101] Figure 4 This is the result of microscopic observation of Example 1. As shown in the figure, the aerogel is evenly wrapped on the fiber.

[0102] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

[0103] The present invention and its embodiments are described above. Such description is not restrictive. The drawings show only one embodiment of the present invention, and actual applications are not limited thereto. In short, if a person skilled in the art is inspired by the above, and does not deviate from the purpose of the present invention, any method and embodiment similar to the technical solution without creative design shall fall within the scope of protection of the present invention.

Claims

1. A water-repellent and heat-retaining fiber aerogel composite material, characterized by: The invention comprises the following components in parts by weight: 13-18 parts of water-repellent and heat-retaining aerogel and 53-76 parts of a multi-layer hydrophobic fiber web; the water-repellent and heat-retaining aerogel is a polyvinyl alcohol-cage silsesquioxane aerogel prepared from polyvinyl alcohol and vinyltrimethoxysilane; the multi-layer hydrophobic fiber web is prepared from hollow high-low temperature melting fibers with a skin-core structure and ultra-fine polyester fibers; The preparation method of the water-repellent and heat-retaining aerogel specifically comprises the following steps: S1. Add vinyltrimethoxysilane to ethyl acetate and stir in a water bath to obtain a mixed solution; S2, adding the hydrochloric acid solution dropwise to the mixed solution obtained in S1 until the pH is 4-5, stirring in a water bath to obtain a reaction solution, adding the ethanol solution to the reaction solution, filtering, washing with an ethanol solution having a mass concentration of 85-90% for 3 times, and drying to obtain a cage-type silsesquioxane; S3, adding polyvinyl alcohol to deionized water, stirring in a water bath at 90° C. for 3 h to obtain a polyvinyl alcohol aqueous solution; S4, adding the cage-type silsesquioxane obtained in S2 to the polyvinyl alcohol aqueous solution obtained in S3, and stirring at a speed of 1200-1300 rpm for 15-20 minutes to obtain a mixed solution; S5. Add the mixed solution obtained in S4 into a mold and quickly freeze it using liquid nitrogen. After freezing, freeze-dry it at a vacuum degree of 10 Pa for 3 days to obtain a water-repellent and heat-retaining aerogel.

2. The water-repellent and heat-insulating fiber aerogel composite material according to claim 1, characterized in that: The water-repellent and heat-insulating aerogel comprises the following components in parts by weight: 30-45 parts of polyvinyl alcohol and 5-7 parts of vinyltrimethoxysilane.

3. The water-repellent and heat-retaining fiber aerogel composite material according to claim 2, characterized in that: The multi-layer hydrophobic fiber web comprises the following components in parts by weight: 21-39 parts of polyethylene terephthalate and 12-21 parts of polyethylene.

4. The method for preparing a water-repellent and heat-retaining fiber aerogel composite material according to claim 1, wherein: The specific steps include: The water-repellent and thermal-insulating aerogel is crushed into particles of 15-20 μm and placed in a powder box. A conveyor belt running at a speed of 10-20 m / s drives the multi-layer fiber web into the powder box. The aerogel particles are dispersed on the multi-layer fiber web, passed through a roller with a thickness of 2 / 3 of the multi-layer fiber web, and heated in a dryer at a temperature of 135-150°C. Subsequently, the aerogel is blown downward and drawn upward by a blower at a temperature of 10-15°C and a wind speed of 8-10 m / s to obtain a water-repellent and thermal-insulating fiber aerogel composite material.

5. The method for preparing the water-repellent and heat-retaining fiber aerogel composite material according to claim 4, characterized in that: The method for preparing the multi-layer hydrophobic fiber web specifically comprises the following steps: (1) Polyethylene terephthalate and polyethylene are sliced, and after feeding, pre-crystallization, and drying, they enter the screw extruder, pass through the pre-filter unit, and enter the two-component composite spinning machine through the distribution pipeline. Composite hollow spinning components are used for composite spinning to obtain polyester fiber / polyethylene composite hollow fibers with specifications of 2.8 dex and 3.8 mm; (2) Polyethylene terephthalate is sliced, and after feeding, pre-crystallization, and drying, it enters the screw extruder, passes through the pre-filter unit, and enters the spinning machine through the distribution pipeline for composite spinning to obtain polyester fibers with specifications of 0.58-1.2dex and 38-50mm; (3) The polyester fiber / polyethylene composite hollow fiber obtained in step (1) and the polyester fiber obtained in step (2) are opened separately using an opening machine, and blended using a blending machine at a mass ratio of 1:0.8-1.

5. After being combed by a single-cylinder double-doffer carding machine, they are laid to obtain a multi-layer fiber web with a thickness of 0.5-3.5 cm and a square gram weight of 40-80 g.

6. The method for preparing the water-repellent and heat-retaining fiber aerogel composite material according to claim 5, characterized in that: In S1, the amount of vinyltrimethoxysilane added to ethyl acetate is 0.18-0.22 g / mL; the water bath temperature is 30-40° C., the stirring rate is 50-60 rpm, and the time is 10-15 min.

7. The method for preparing the water-repellent and heat-retaining fiber aerogel composite material according to claim 6, characterized in that: In S2, the mass concentration of the hydrochloric acid solution is 18-20%, the water bath temperature is 30-35°C, the stirring rate is 60-80 rpm, and the time is 30-40 h.

8. The method for preparing the water-repellent and heat-retaining fiber aerogel composite material according to claim 7, characterized in that: In S2, the ethanol concentration was 73-76%, and the amount added to the reaction solution was 1.2-1.4 g / mL.

9. The method for preparing the water-repellent and heat-retaining fiber aerogel composite material according to claim 8, characterized in that: In S3, the amount of polyvinyl alcohol added to water was 0.1-0.12 g / mL.

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