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...

AI Technical Summary

Problems solved by technology

Therefore, when the silica airgel and its composite materials prepared by the traditional process are placed in an environment above 500°C, high-temperature heat release and fire will inevitably occur, and it is difficult to pass the GB8624-2012 building materials and The detection of its product combustion performance classification (A1 level) (the detection requires no combustion at a high temperature of 750 ° C, or the flame duration does not exceed 20s), so there are safety hazards in the use of airgel products under certain high-demand conditions. It also limits the scope of application and market of airgel products

At the same time, the use of a large number of surface modifiers in traditional processes will also have a certain degree of impact on human health and production safety.