Hydrophobic silicon dioxide aerogel composite material with high thermal stability and low calorific value and preparation method thereof

A technology of hydrophobic silica and high thermal stability, which is applied in the fields of chemical instruments and methods, silicon compounds, inorganic chemistry, etc., and can solve the problem of thermal stability and combustion performance without significant improvement and without significant improvement of silica Issues such as thermal stability and combustion performance of airgel composites

Active Publication Date: 2021-10-29
CENT SOUTH UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

At present, the thermal stability and combustion performance of the high-temperature-resistant silica airgel blankets on the market have not been greatly improved. For example, the Chinese patent with the publication number CN106587908A provides a high-temperature-resistant hydrophobic silica airgel The preparation method of rubber heat insulation blanket, and its relevant data show that this preparation method does not greatly improve the thermal stability and combustion performance of silica airgel composites

Method used

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Examples

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Comparison scheme
Effect test

preparation example Construction

[0033] The invention provides a method for preparing a hydrophobic silica airgel composite material with high thermal stability and low calorific value, comprising the following steps:

[0034] Adding an alcohol solvent, a hydrophobic modifier and an acidic catalyst in sequence to the inorganic silicon source wet gel to perform the first hydrophobic modification to obtain a hydrophobic silica wet gel;

[0035] impregnating the matrix material in the hydrophobic silica wet gel to obtain a pretreated composite material;

[0036] The pretreatment composite material is sequentially dried and heat-treated in a protective atmosphere to obtain the hydrophobic silica airgel composite material with high thermal stability and low calorific value.

[0037] In the present invention, unless otherwise specified, the raw materials used in the present invention are preferably commercially available products.

[0038] In the present invention, an alcohol solvent, a hydrophobic modifier and an...

Embodiment 1

[0090] The preparation process of Example 1 and Comparative Example 1 is the same. After obtaining the pretreated composite material, the pretreated composite material was put into a tube furnace filled with argon, and kept at a temperature of 120° C. for 4 hours to obtain a hydrophobic silica airgel composite material. Continue to place the hydrophobic silica airgel composite material in the tube furnace at a heating rate of 10°C / min, raise the temperature to 250°C, heat treatment for 2 hours, and obtain a hydrophobic silica airgel composite material with high thermal stability and low combustion calorific value. Silica airgel composites.

[0091] The performance parameters of the obtained composite material: the size is 100×40×1.5mm, the density is ~0.18g / cm 3 , thermal conductivity ~ 35.6mW / (m k), contact angle ~ 143°, total combustion calorific value (GCV) is 3.6MJ / kg, peak heat release rate (T peak ) is 507°C.

Embodiment 2

[0093] The preparation process of Example 2 is the same as that of Comparative Example 1. After obtaining the pretreated composite material, the pretreated composite material was put into a tube furnace filled with argon, and kept at a temperature of 120° C. for 4 hours to obtain a hydrophobic silica airgel composite material. Put the hydrophobic silica airgel composite in the tube furnace at a heating rate of 10°C / min, raise the temperature to 700°C, heat treatment for 2 hours, and finally obtain a composite material with high thermal stability and low combustion calorific value. Hydrophobic silica airgel composites.

[0094] The performance parameters of the obtained composite material: the size is 100×40×1.5mm, the density is ~0.24g / cm 3 , thermal conductivity ~41.2mW / (m k), contact angle ~133°, total combustion calorific value (GCV) is 3.2MJ / kg, peak heat release rate (T peak ) is 620°C.

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Abstract

The invention belongs to the technical field of thermal insulation composite materials, and provides a hydrophobic silica aerogel composite material with high thermal stability and low calorific value and a preparation method thereof. The preparation method comprises the following steps: by taking an inorganic silicon source as a precursor, gelatinizing and modifying to obtain hydrophobic gel; then dipping a base material in the hydrophobic gel to obtain a pretreated composite material; when an organic silicon source is used as the precursor, adding the base material in the gelation process, so that the base material fully adsorbs the silicon source hydrolysate; sequentially carrying out alcohol replacement and alkane replacement on the gel composite system to obtain a pretreated composite material; and then subjecting the pretreated composite material to heat treatment, so that the number of methyl groups on the surface of the silicon dioxide aerogel is orderly reduced, residual organic liquid on the surface and in pores of the silicon dioxide aerogel is reduced, and the microstructure of the silicon dioxide aerogel is optimized, so that the final composite material has high thermal stability and low combustion heat value.

Description

technical field [0001] The invention relates to the technical field of thermal insulation composite materials, in particular to a hydrophobic silica airgel composite material with high thermal stability and low calorific value and a preparation method thereof. Background technique [0002] Silica airgel has a typical three-dimensional nanoporous network structure with extremely low density (≈3kg / m 3 ), extremely low thermal conductivity (≤0.016W / (m k)), high specific surface area (≥800m 2 / g). The extremely low thermal conductivity of silica airgel makes it have a huge application space and market in the field of thermal insulation. In addition, most silica aerogels are fragile and poorly shaped, so silica aerogels on the market are mainly powder and block particles. [0003] Powdered silica airgel is compounded with functional materials to obtain a composite material with both silica properties and functional material properties, so that silica airgel can be used in pipe...

Claims

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Application Information

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Patent Type & AuthorityApplications(China)
IPC IPC(8): C04B30/02C01B33/158
CPCC04B30/02C01B33/1585C04B2201/32C04B2201/20C04B14/42
Inventor李治邓云猛吴丽玲邓曦孙梦田王小武王洋刘琼
OwnerCENT SOUTH UNIV