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.