A preparation method of hydrophobic silica airgel thermal insulation composite material

Abstract

The invention relates to a method for preparing a hydrophobic silica airgel thermal insulation composite material, comprising the following steps: (1) Preparation of silica sol: using siloxane as a precursor, adding an organic solvent, water and an acid catalyst , to obtain silica sol; (2) Preparation of composite gel: add flame retardant and infrared blocking agent to silica sol, stir evenly; add alkali catalyst, immerse inorganic fiber products in silica sol, Stand still; (3) solvent replacement: replace the composite gel with an organic solvent; (4) dry: dry the composite gel. The invention has the advantages of simple process, short production cycle, low cost, low equipment requirements, controllable reaction conditions, and excellent product performance, and the prepared silica airgel composite material has overall waterproof performance, extremely low thermal conductivity, and excellent high temperature Thermal insulation performance, under the condition of ensuring the overall hydrophobicity of the material, it can pass the non-combustibility test, and its non-combustibility test can reach A1 level.

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.