Preparation method of hydrophobic silica aerogel heat-insulation composite material

Abstract

The invention relates to a preparation method of a hydrophobic silica aerogel heat-insulation composite material. The method comprises steps as follows: (1) preparation of silica sol: siloxane is used as a precursor, an organic solvent, water and an acid catalyst are added, and the silica sol is obtained; (2) preparation of composite gel: a flame retardant and an infrared blocking agent are added to the silica sol, the mixture is evenly mixed, a base catalyst is added, an inorganic fiber product is immersed in the silica sol, and the mixture is left to stand; (3) solvent replacement: the composite gel is replaced by the organic solvent; (4) drying: the composite gel is dried. With the adoption of the method, the process is simple, the production cycle is short, the cost is lower, the equipment requirement is low, reaction conditions are controllable, product performance is excellent, and the prepared silica aerogel composite material has the overall waterproof performance, the extremely low heat conductivity coefficient and the excellent high-temperature heat-insulation performance, can pass an incombustibility test under the condition that the material is ensured to be hydrophobic as a whole and reaches level A1 according to the incombustibility test.

Description

technical field

[0001] The invention relates to a preparation method of an airgel thermal insulation material, in particular to a preparation method of a hydrophobic silica airgel thermal insulation composite material. Background technique

[0002] Silica airgel is a low-density, high-porosity nanoporous amorphous solid material with high light transmittance. It is also called "blue smoke" and "solid smoke". The pores are filled with gaseous dispersion media. , with a continuous nano-scale three-dimensional network structure and holes, is the solid material with the lowest density and the lowest thermal conductivity known in the world. Its pore size and network skeleton are both nanoscale, the size distribution range of pores is 1-100 nanometers, and the particle size distribution range of network skeleton is 1-30 nanometers. This special structure makes it have high porosity (80%-99.8%) , low density (3~250kg / m3), high specific surface area (500~1000m2 / g), low dielectric c...