Halogen-free ammonia-free aerogel composite coiled material produced by supercritical process

Abstract

The invention discloses a halogen-free ammonia-free aerogel composite coiled material produced by a supercritical process. The aerogel composite coiled material has the density of 160-180 kg / m<3>, theheat conductivity coefficient of less than or equal to 0.018 W / (m.K), the hydrophobicity of more than or equal to 99.5% and the vibration mass loss rate of less than 0.1%. A preparation process of the aerogel composite coiled material comprises the following steps: S1, adding ethanol and water into tetraethoxysilane serving as a raw material, and keeping the temperature at 50 DEG C for 24 hours to obtain a first mixed solution; adding ammonia-free alkali into the modified organic silicon ester, ethanol and water to obtain a second mixed solution; S2, mixing the first mixed solution and the second mixed solution in proportion to obtain a third mixed solution, and immersing a fiber coiled material in the third mixed solution to form a gel composite coiled material; and S3, carrying out supercritical drying on the gel composite coiled material to obtain the halogen-free ammonia-free aerogel composite coiled material. The product does not contain halogen elements, does not volatilize ammonia-containing irritant gas at a high temperature, and can be used for heat insulation and preservation in an indoor high-temperature environment and fire prevention and heat insulation under a thermal instability condition.

Description

technical field [0001] The invention relates to the field of nanoporous airgel composite thermal insulation products. More specifically, the present invention relates to an airgel composite coil produced by a halogen-free and ammonia-free supercritical process. Background technique [0002] Airgel is a nanoporous, low-density, amorphous solid material with a continuous three-dimensional network structure. The common silica airgel has a porosity of over 90% and an average pore size of 20-40nm. It has the advantages of low thermal conductivity, low density, and small specific heat capacity. It plays an important role in the fields of heat insulation, flame retardant and fire prevention. At present, silica airgel has been put into production and use at home and abroad, and the domestic industrialization scale is growing rapidly. It has been put into use in many fields such as industrial equipment and pipelines, new energy vehicles, fire safety, building fire protection and ene...

AI Technical Summary

Problems solved by technology

[0005] Patent CN201810005328 reports a method for preparing silica airgel composite materials using a chlorine-free and alcohol-free process. The fire resistance and strength of airgel products will destroy the continuous three-dimensional network structure of airgel nanoporous, and at the same time, it is easy to produce toxic and harmful gases when used at high temperature, which will affect the performance and service life of airgel products, and limit the The service temperature and fire performance of airgel products

In addition, the report adopts an atmospheric pressure drying process, which is difficult to avoid the destruction of the microstructure of the gel caused by capillary force during the drying process, which will seriously pulverize the final product and reduce the thermal insulation performance and user experience of the airgel product.