1. The preparation method of the aerogel modified fiber felt heat insulation composite material is characterized by comprising the following steps of:

s1 SiO₂-RF sol compounding the fiber mat to obtain a wet gel fiber mat;

s2, aging and modifying the wet gel fiber felt, and drying to obtain the aerogel modified fiber felt heat insulation composite material.

2. The method of making an aerogel modified fiber mat insulation composite as claimed in claim 1, wherein: the fiber felt comprises one or the combination of more than two of rock wool fiber felt, glass fiber felt, carbon fiber felt, mullite fiber felt, quartz fiber felt, aluminum silicate fiber felt, ceramic fiber felt, alumina fiber felt, rock wool fiber felt, ramie fiber felt, basalt fiber felt, polyacrylonitrile fiber felt, PET fiber felt and PP fiber felt.

3. The method of making an aerogel modified fiber mat insulation composite as claimed in claim 1, wherein step S1 further comprises the substeps of:

S11、SiO₂preparation of RF sol: dissolving a phenol precursor in an organic solvent, and sequentially adding an alkaline catalyst and a silicon source reagent until the silicon source reagent is completely hydrolyzed to obtain SiO₂-an RF sol.

4. The method of making an aerogel modified fiber mat insulation composite as claimed in claim 3, wherein: the phenol precursor comprises one or the combination of more than two of resorcinol, phloroglucinol and phenolic resin.

5. The method of making an aerogel modified fiber mat insulation composite as claimed in claim 1, wherein: step S1 further includes the following sub-steps:

s12, mixing SiO₂-subjecting the RF sol composite fiber mat to gel modification in a closed environment to obtain the wet gel fiber mat.

6. The method of making an aerogel modified fiber mat insulation composite as claimed in claim 5, wherein: in the step S12, the temperature of gel modification is below 50 ℃, and the time of gel modification is 1-2.5 h.

7. The method of making an aerogel modified fiber mat insulation composite as claimed in claim 1, wherein step S2 further comprises the steps of: and soaking the wet gel fiber felt in a mixed solution of trimethylchlorosilane, absolute ethyl alcohol and normal hexane for aging modification in a closed environment.

8. The method of making an aerogel modified fiber mat insulation composite as claimed in claim 7, wherein: the volume ratio of the trimethylchlorosilane to the absolute ethyl alcohol to the normal hexane in the mixed solution is 0.2-0.5: 1.5-1.8: 8.

9. The method of making an aerogel modified fiber mat insulation composite as claimed in claim 1, wherein: in the step S2, the temperature of the aging modification is below 50 ℃, and the time of the aging modification is 17-24 hours.

10. An aerogel modified fiber mat insulation composite made by the method of any of claims 1-9.

Background

According to statistics, the building energy consumption accounts for more than 35% of the total social energy consumption, and the huge broken discharge amount caused by the fact causes serious harm to the ecological environment. The use of heat insulation materials at building envelope parts to improve the heat insulation performance of buildings is an important means for reducing the energy consumption of the buildings, and rock wool products are internationally recognized as main energy-saving materials in fifth conventional energy sources due to the excellent fireproof heat insulation characteristics of the rock wool products. Every 1 ton of rock wool products are used for heat preservation in a building, energy equivalent to 1 ton of petroleum can be saved at least one year, and the low-carbon, energy-saving and emission-reduction trends are met. The fireproof heat-insulating material is used as two most widely applied inorganic heat-insulating materials, has good fireproof performance and durability, but has generally high thermal conductivity and water absorption rate, so that the heat-insulating performance of the fireproof heat-insulating material is influenced.

The aerogel consists of a nano network formed by mutual aggregation of colloidal particles or high polymer molecules and nano pores formed by the nano network, the porosity is more than 80 percent, the pore size is 2-100nm, and the specific surface area is 300-1000m²Is a highly dispersed solid material. SiO 2₂The RF aerogel material is a novel thermal protection material, and is a gel material with a three-dimensional network space structure, the voids of the gel material are filled with gas, the diameter of particles generally constituting the structure and the pore size formed between the particles are in the nanometer size range, the nanopores limit the flow of gas molecules inside the material due to the temperature rise, and the thermal conductivity of the material is greatly reduced due to the complicated gas flow path, so that the material has good thermal insulation performance, and can be widely used in aerospace and civil fields. Compared with the traditional heat-insulating materials such as glass wool, polystyrene foam (EPS), extruded polystyrene foam plastic (XPS) plates and the like, SiO₂RF aerogels exhibit more excellent effects in the field of thermal insulation.

Xi ' an University of Architecture and TechnologyWu Shi Ju of academy of building and Equipment science and engineering prepares a SiO₂The aerogel composite rock wool building thermal insulation material has the best short-term water absorption rate of 0.8kg/m²The maximum compressive strength is 0.0424MPa, and the thermal conductivity is 0.033-0.042W/(m.K). In a comprehensive way, the material basically meets the requirements of external wall external thermal insulation in the building industry at present, but the material has the hidden trouble problems of unreported density, higher thermal conductivity coefficient, higher water absorption rate, easy moisture absorption of the thermal insulation material, decline of thermal insulation efficiency, short service life and the like.

CN201911082787.X A preparation method of a powder-dropping-preventing composite silica aerogel felt, which adopts a silica aerogel felt prepared from a silica aerogel modified fiber felt, uniformly coats slurry on one surface of the silica aerogel felt, then superposes another silica aerogel felt on the silica aerogel felt, repeatedly superposes the silica aerogel felt for multiple times in a silica aerogel felt-slurry-silica aerogel felt mode, and carries out treatment by methods such as hot press molding to obtain the composite silica aerogel felt, wherein the thermal conductivity of the composite silica aerogel felt is improved, the thermal conductivity can be 0.021W/(m.K), and the compressive strength can be 2.1 Mpa. However, the multilayer stacking method causes the composite material to be too thick, which is not beneficial to application; the thermal conductivity of the prepared silica aerogel felt which is not overlapped by multiple layers is still 0.033-0.042W/(m.K) as the test result of the Seian architecture science and technology university.

CN 202011610541.8A high-efficient thermal-insulated heated board and its preparation method, first panel layer and second panel layer are the fiber reinforced resin composite material at the same time; the sandwich layer between the first panel layer and the second panel layer is made of a foam block which is a polyurethane foam block, a PVC foam block or a phenolic foam block; the heat-insulating board manufactured by the method of the multilayer board has a limited application range, and the heat conductivity coefficient and the water absorption rate are not improved at all.

Disclosure of Invention

Technical problem to be solved

In view of the above-mentioned shortcomings and drawbacks of the prior art, the present invention provides an aerogel modified fiber mat thermal insulation composite that addresses the problems of SiO₂Aerogel composite rock wool building thermal insulation material with high thermal conductivity coefficient and high water absorptionThe technical problem is solved;

correspondingly, the invention also provides a preparation method of the aerogel modified fiber felt heat insulation composite material.

(II) technical scheme

In order to achieve the purpose, the invention adopts the main technical scheme that:

the invention provides a preparation method of an aerogel modified fiber felt heat insulation composite material, which comprises the following steps:

s1 SiO₂-RF sol compounding the fiber mat to obtain a wet gel fiber mat;

s2, aging and modifying the wet gel fiber felt, and drying to obtain the aerogel modified fiber felt heat insulation composite material.

Optionally, the fiber felt comprises one or a combination of more than two of rock wool fiber felt, glass fiber felt, carbon fiber felt, mullite fiber felt, quartz fiber felt, aluminum silicate fiber felt, ceramic fiber felt, alumina fiber felt, rock wool fiber felt, ramie fiber felt, basalt fiber felt, polyacrylonitrile fiber felt, PET fiber felt and PP fiber felt.

Optionally, step S1 further includes the following sub-steps:

S11、SiO₂preparation of RF sol: dissolving a phenol precursor in an organic solvent, and sequentially adding an alkaline catalyst and a silicon source reagent until the silicon source reagent is completely hydrolyzed to obtain SiO₂-an RF sol.

Optionally, the phenol precursor comprises one or a combination of more than two of resorcinol, phloroglucinol and phenolic resin.

Optionally, step S1 further includes the following sub-steps:

s12, mixing SiO₂-subjecting the RF sol composite fiber mat to gel modification in a closed environment to obtain the wet gel fiber mat.

Optionally, in step S12, the temperature of the gel modification is below 50 ℃, and the time of the gel modification is 1-2.5 h.

Optionally, step S2 further includes the steps of: and soaking the wet gel fiber felt in a mixed solution of trimethylchlorosilane, absolute ethyl alcohol and normal hexane for aging modification in a closed environment.

Optionally, the volume ratio of the trimethylchlorosilane to the absolute ethyl alcohol to the n-hexane in the mixed solution is 0.2-0.5: 1.5-1.8: 8.

Optionally, in step S2, the temperature of the aging modification is below 50 ℃, and the time of the aging modification is 17-24 hours.

In a second aspect, the invention provides an aerogel modified fiber felt thermal insulation composite material prepared by the preparation method in any one of the above schemes.

(III) advantageous effects

The invention has the beneficial effects that: the aerogel modified fibrofelt heat-insulating composite material adopts SiO₂The RF aerogel modifies the fiber felt, compared with the traditional organic foam external wall external thermal insulation material and a pure fiber material, the fiber felt has a three-dimensional nano porous network structure, the thermal conductivity of the fiber felt is reduced, the problems of poor fire resistance grade, poor oxidation resistance and high water absorption of the traditional organic foam thermal insulation material are solved, the mechanical property of the fiber felt is improved, the fiber felt has good thermal stability, chemical stability, structural stability and sound insulation performance, the high specific surface area of the fiber felt also endows the fiber felt with good thermal insulation and high temperature resistance, the fiber felt can be used in an environment below 450 ℃, and meanwhile, the fiber felt has good hydrophobicity;

in the preparation method, the aerogel modified fiber felt heat-insulation composite material can be prepared in a short time; the preparation process is simple, and the problem that the existing modified fiber felt heat-insulation composite material is complex in preparation process is solved; the aerogel modified fiber felt heat insulation composite material prepared by the method has good stability. The aerogel modified fiber felt heat insulation composite material can be used as a heat insulation plate for external heat insulation of an external wall with low heat conductivity and high strength, so that the aerogel modified fiber felt heat insulation composite material has a wider application prospect in the fields of external heat insulation of the external wall, high-temperature heat insulation, low-temperature cold insulation and the like.

Drawings

FIG. 1 is a contact angle test chart of a rock wool fiber mat heat insulation composite material prepared in example 1 of the present invention;

FIG. 2 is a macroscopic view of a rock wool fiber mat heat insulation composite material prepared in example 1 of the present invention;

fig. 3 is a microscopic view of a rock wool fiber mat heat insulation composite material prepared in example 1 of the present invention.

FIG. 4 is a test chart of the tear strength of a rock wool fiber mat heat insulation composite material prepared in example 1 of the present invention.

Detailed Description

For a better understanding of the present invention, reference will now be made in detail to the present invention by way of specific embodiments thereof.

The invention provides a preparation method of an aerogel modified fiber felt heat insulation composite material, aiming at solving the problems of higher heat conductivity coefficient and higher water absorption rate of the heat insulation composite material prepared by the existing aerogel modified fiber felt₂The modification of the fiber mat by the RF aerogel can greatly reduce the conductivity of the prepared composite material, so that the composite material can be applied to a higher-temperature environment.

The preparation method comprises the following steps:

s1 SiO₂-RF sol compounding the fiber mat to obtain a wet gel fiber mat;

s2, aging and modifying the wet gel fiber felt, and drying to obtain the aerogel modified fiber felt heat insulation composite material.

The fiber mat of the present invention may be, but is not limited to, one or a combination of two or more of rock wool fiber mat, glass fiber mat, carbon fiber mat, mullite fiber mat, quartz fiber mat, aluminum silicate fiber mat, ceramic fiber mat, alumina fiber mat, rock wool fiber mat, ramie fiber mat, basalt fiber mat, polyacrylonitrile fiber mat, PET fiber mat, and PP fiber mat.

The rock wool fibrofelt is used as a base material, and SiO is prepared by a sol-gel method and a one-pot method₂RF sols, by atmospheric pressure impregnation of substrates with SiO₂Compounding with RF sol, and drying at normal pressure to obtain SiO with low heat conductivity and high strength₂-RF aerogel modified rock wool fibrofelt thermal insulation composite having a three-dimensional nanoporous network structure that reduces the thermal conductivity of rock wool fibrofelt and solves the traditional organic problemThe foam heat insulation material has the problems of poor fire grade and poor oxidation resistance, has good thermal stability, chemical stability, structural stability and sound insulation performance, and is endowed with good heat insulation and high temperature resistance by high specific surface area, so the foam heat insulation material is an ideal heat insulation material.

To prepare SiO with stronger stability₂RF aerogel, step S1 further comprising the following sub-steps: s11, SiO₂Preparation of RF sol: dissolving a phenol precursor in an organic solvent, and sequentially adding an alkaline catalyst and a silicon source reagent until the silicon source reagent is completely hydrolyzed to obtain SiO₂-an RF sol.

The phenol precursor may be, but not limited to, one or a combination of two or more of resorcinol, phloroglucinol, and phenolic resin.

The organic solvent may be one or a combination of two or more of methanol, absolute ethanol, propanol and butanol, and the purity is preferably analytical purity.

The aldehyde precursor is formaldehyde or/and acetaldehyde.

The basic catalyst can be one or the combination of more than two of 3-aminopropyl triethoxysilane, sodium carbonate solution, potassium carbonate solution and sodium hydroxide solution;

the silicon source reagent may be, but is not limited to, tetraethyl orthosilicate, 3-aminopropyltriethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, or a combination of two or more thereof.

Wherein the molar ratio of the phenol precursor to the organic solvent to the aldehyde precursor to the basic catalyst to the silicon source reagent is 1 (73.6-80.3) to 1.7-2.4 to 0.3-0.45 to 0.082-0.14.

Above SiO₂The preparation of RF aerogels was carried out at room temperature.

For increasing SiO₂RF aerogel modification the stability of the aerogel fiber blanket of the invention made and provides a simple method of aging modification, step S1 further comprising the following sub-steps:

s12, mixing SiO₂-RF sol composite fiber felt on the sealing ringAnd carrying out gel modification under the environment to obtain the wet gel fiber felt.

Wherein, the modification is carried out in a closed environment. SiO 2₂The RF sol is preferably poured directly into a vessel containing the fiber mat and SiO₂-the RF sol level exceeds the height of the rock wool fiber mat;

in step S12, the temperature of gel modification is below 50 ℃, and the time of gel modification is preferably 1-2.5 h. The gel modification temperature may be set at any normal temperature of 50 ℃ or lower, or may be set at 50 ℃.

Step S2 further includes the steps of: and soaking the wet gel fiber felt in a mixed solution of trimethylchlorosilane, absolute ethyl alcohol and normal hexane for aging modification in a closed environment.

The volume ratio of the trimethylchlorosilane, the absolute ethyl alcohol and the normal hexane in the mixed solution is preferably 0.2-0.5: 1.5-1.8: 8.

In order to enable the prepared aerogel modified fiber felt heat insulation composite material to have better stability, in the step S2, the temperature of aging modification is below 50 ℃, and the time of aging modification is 17-24 hours. The drying environment may be a natural drying environment; the drying time is 3-4 days.

In the embodiment of the invention, the fiber felt is selected as the modified substrate, and the prepared SiO₂The density of the rock wool fibrofelt heat-insulation composite material modified by the RF aerogel is 0.150-0.160 g/cm³The compression strength is 0.15-0.18 MPa, the tear strength is 0.11-0.14 MPa, and the thermal conductivity is

0.026-0.030W/(m.K), a hydrophobic angle of 134-138.8 DEG, and a specific surface area of 509-520 m²/g。

In order to better understand the above technical solutions, exemplary embodiments of the present invention will be described in more detail below. While exemplary embodiments of the invention are shown in the drawings, it should be understood that the invention can be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

Example 1

SiO₂-preparation of RF aerogel modified rock wool fiber mat insulation composite:

s1, weighing 0.075mol of resorcinol, pouring the resorcinol into a beaker, adding 5.83mol of absolute ethyl alcohol, stirring until the resorcinol is dissolved, adding 0.15mol of formaldehyde solution, dropwise adding 0.03mol of 3-aminopropyl triethoxysilane, stirring uniformly, adding 0.0075mol of methyl triethoxysilane, and hydrolyzing the methyl triethoxysilane for 1 hour to form SiO₂-an RF sol;

s2 placing the rock wool fibrofelt into a container, and adding the prepared SiO₂The RF sol is poured into a container containing a rock wool fiber mat, the container is sealed and the gel forms SiO after 1h at room temperature₂-RF wet gel modified rock wool fiber mat composite;

s3 SiO obtained₂Soaking the RF wet gel modified rock wool fibrofelt composite material in 500ml of mixed solution of trimethylchlorosilane, absolute ethyl alcohol and normal hexane in a volume ratio of 0.5:1.5:8, sealing, and aging and modifying for 18h at room temperature;

s4 aging the modified SiO₂The rock wool fibrofelt heat-insulating composite material modified by the RF wet gel is taken out and dried for 3 days at normal temperature and normal pressure to obtain the SiO with high compressive strength and low thermal conductivity in the embodiment₂-RF aerogel modified rock wool fiber mat thermal insulation composite.

The density of the composite material prepared in this example was 0.152g/cm³The compressive strength is 0.15MPa, the tear strength is 0.112MPa, the thermal conductivity is 0.0263W/(m.K), the hydrophobic angle is 138 degrees, and the specific surface area is 520m²/g。

SiO produced in this example₂The results of the contact angle test, the macroscopic sample test, the microscopic morphology test, and the tear strength test of the RF aerogel modified rock wool fiber mat thermal insulation composite are shown in fig. 1, fig. 2, fig. 3, and fig. 4, respectively.

Testing one:

the hydrophobicity of the surface of the composite material of this example was measured at room temperature of 25 ℃ using a DSA200 contact angle goniometer, and the data shown in fig. 1 were obtained. As can be seen from fig. 1, the composite material obtained in this embodiment has strong hydrophobicity, which provides an important guarantee for improving the service life of rock wool;

and (2) testing: a macroscopic picture of the composite material obtained in the embodiment shown in fig. 2 is obtained by photographing;

and (3) testing: microscopic examination of the composite material obtained in this example at 5000 times magnification was performed using an SU8010 scanning electron microscope, and a test chart shown in fig. 3 was obtained;

fig. 2 and 3 show that: the rock wool fibrofelt has been SiO₂RF aerogel pack and cover, indicating atmospheric impregnation of SiO₂The RF sol can be sufficiently absorbed into a matrix, and a composite material is successfully prepared;

and (4) testing: the material obtained in this example was subjected to a test of tensile properties (tear strength) in the direction perpendicular to the sheet surface using a DECCA-I universal tester, and data as shown in fig. 4 were obtained. As can be seen from FIG. 4, the composite material of the embodiment has good tear resistance and can meet the requirement of a building material for external thermal insulation of an external wall.

Example 2

SiO₂-preparation of RF aerogel modified rock wool fiber mat insulation composite:

s1, weighing 0.083mol of phloroglucinol, pouring the phloroglucinol into a beaker, adding 6.3mol of methanol, stirring until the mixture is dissolved, adding 0.18mol of acetaldehyde solution, dropwise adding 0.033mol of sodium carbonate solution (1mol/L), stirring uniformly, adding 0.008mol of tetraethyl orthosilicate, and hydrolyzing the tetraethyl orthosilicate for 2 hours to form SiO₂-an RF sol;

s2 placing the rock wool fibrofelt into a container, and adding the prepared SiO₂The RF sol is poured into a container containing a rock wool fiber mat, the container is sealed and the gel forms SiO after 2.5h at 40 DEG C₂-RF wet gel modified rock wool fiber mat insulation composite;

s3 SiO obtained₂Soaking the RF wet gel modified rock wool fibrofelt heat insulation composite material in 500ml of mixed solution of trimethylchlorosilane, absolute ethyl alcohol and normal hexane with the volume ratio of 0.3:1.7:8, sealing, and adding the mixture into a containerAging and modifying for 20h at 50 ℃;

s4 aging the modified SiO₂The rock wool fibrofelt heat-insulating composite material modified by the RF wet gel is taken out and dried for 3 days at normal temperature and normal pressure to obtain the SiO with high compressive strength and low thermal conductivity in the embodiment₂-RF aerogel modified rock wool fiber mat thermal insulation composite.

In this example, the density of the composite material was 0.154g/cm³The compressive strength is 0.158MPa, the tear strength is 0.123MPa, the thermal conductivity is 0.0271W/(m.K), the hydrophobic angle is 135.1 degrees, and the specific surface area is 515m²/g。

Example 3

SiO₂-preparation of RF aerogel modified rock wool fiber mat insulation composite:

s1, weighing 0.097mol of resorcinol, pouring into a beaker, adding 7.37mol of butanol, stirring until the resorcinol is dissolved, adding 0.195mol of acetaldehyde solution, dropwise adding 0.04mol of sodium hydroxide solution (1mol/L), stirring uniformly, adding 0.01mol of methyltrimethoxysilane, and hydrolyzing the methyltrimethoxysilane for 1h to form SiO₂-an RF sol;

s2 placing the rock wool fibrofelt into a container, and adding the prepared SiO₂The RF sol is poured into a container containing a rock wool fiber mat, the container is sealed and the gel forms SiO after 1.5h at 30 DEG₂-RF wet gel modified rock wool fiber mat insulation composite;

s3 SiO obtained₂Soaking the RF wet gel modified rock wool fibrofelt heat insulation composite material in 500ml of mixed solution of trimethylchlorosilane, absolute ethyl alcohol and normal hexane in a volume ratio of 0.2:1.8:8, sealing, and aging and modifying for 22h at 40 ℃;

s4 aging the modified SiO₂The rock wool fibrofelt heat-insulating composite material modified by the RF wet gel is taken out and dried for 4 days at normal temperature and normal pressure to obtain the SiO with high compressive strength and low thermal conductivity in the embodiment₂-RF aerogel modified rock wool fiber mat thermal insulation composite.

The density of the composite material obtained in this example was 0.156g/cm³Compressive strength of 0.163MPa and tear resistanceThe cracking strength is 0.132MPa, the thermal conductivity is 0.0285W/(m.K), the hydrophobic angle is 134.8 degrees, and the specific surface area is 511m²/g。

Example 4

SiO₂-preparation of RF aerogel modified rock wool fiber mat insulation composite:

s1, weighing 0.1mol of phenolic resin, pouring the phenolic resin into a beaker, adding 7.6mol of absolute ethyl alcohol, stirring until the phenolic resin is dissolved, adding 0.19mol of formaldehyde solution, dropwise adding 0.041mol of potassium carbonate solution (1mol/L), uniformly stirring, adding 0.012mol of 3-aminopropyltriethoxysilane, and hydrolyzing the 3-aminopropyltriethoxysilane for 1.5h to form SiO₂-an RF sol;

s2 placing the rock wool fibrofelt into a container, and adding the prepared SiO₂The RF sol is poured into a container containing a rock wool fibre mat, the container is sealed and the gel forms SiO after 1.5h at 50 DEG₂-RF wet gel modified rock wool fiber mat insulation composite;

s3 SiO obtained₂Soaking the RF wet gel modified rock wool fibrofelt heat insulation composite material in 500ml of mixed solution of trimethylchlorosilane, absolute ethyl alcohol and normal hexane in a volume ratio of 0.4:1.6:8, sealing, and aging and modifying for 24 hours at room temperature;

s4 aging the modified SiO₂The rock wool fibrofelt heat-insulating composite material modified by the RF wet gel is taken out and dried for 4 days at normal temperature and normal pressure to obtain the SiO with high compressive strength and low thermal conductivity in the embodiment₂-RF aerogel modified rock wool fiber mat thermal insulation composite.

The density of the composite material in this example was 0.158g/cm³The compressive strength is 0.174MPa, the tear strength is 0.137MPa, the thermal conductivity is 0.0292W/(m.K), the hydrophobic angle is 136.9 degrees, and the specific surface area is 517m²/g。

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.