Hydrophobic silica aerogel heat-insulation composite material and preparation method thereof

Abstract

The invention discloses a hydrophobic silica aerogel heat-insulation composite material and a preparation method thereof. The composite material consists of silica aerogel and an inorganic fiber product, wherein the silica aerogel is doped with a flame retardant and an infrared blocking agent. During preparation of sol, siloxane containing hydrophobic groups is introduced, and the content and the distribution state of the hydrophobic groups in a system are controlled by controlling the reactant content and reaction conditions, so that the composite material can pass the test of GB8624-2012 Classification for Burning Behavior of Building Materials and Products (A1-level). The preparation method of the composite material comprises steps as follows: (1) preparation of the silica sol; (2) preparation of composite gel; (3) solvent replacement; (4) drying. With the adoption of the method, the process is simple, the production cycle is short, the cost is lower, the equipment requirement is low, 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.

Description

technical field [0001] The invention relates to an airgel thermal insulation material and a preparation method thereof, in particular to a hydrophobic silica airgel thermal insulation composite material and a preparation method thereof. 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)...

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.