Aerogel heat insulation composite material and its preparing method

Abstract

The heat insulating composite aerogel material consists of silica aerogel, titania as infrared opacifier and reinforcing fiber in the weight ratio of 1 to 0.1-0.7 to 0.7-3. Its preparation process includes compounding sol with silanolate, surface modifier, titanolate, alcohol solvent, acid catalyst and alkaline catalyst in certain proportion; soaking fiber felt or prefabricated fiber part in the sol; and supercritical fluid drying. The material of the present invention has high blocking effect on solid heat transfer, air heat transfer and infrared radiation heat transfer, excellent hydrophobicity, simple preparation process, low cost, mechanical strength over 2 MPa, and wide application range, and may be used in strict heat protection condition in aeronautics, astronautics, military and civil uses.

Description

technical field [0001] The invention relates to an airgel thermal insulation composite material and a preparation method thereof, in particular to a silica airgel thermal insulation composite material and a preparation method thereof. Background technique [0002] Silica airgel has the characteristics of high specific surface area, ultra-low density and nanoporous network structure, and is considered to be the best solid-state material for thermal insulation (Nicola Huling Ulrich Schubert AngewChem Int Ed.1998, 37:22-45) . However, factors such as inherent low strength, high brittleness, and difficulty in forming airgel materials limit their practical use in large areas or in large areas. Existing ways to solve this problem mainly contain the following classes: (1) adopt organic or inorganic adhesive to mix with airgel powder material, by compression molding (referring to No. 95197068.2 of Chinese patent " a kind of composite material containing airgel...

AI Technical Summary

Problems solved by technology

However, the inherent low strength, high brittleness, and difficulty in forming of airgel materials limit the practical use of large areas or large areas.

Existing ways to solve this problem mainly contain the following classes: (1) adopt organic or inorganic adhesive to mix with airgel powder material, by compression molding (referring to No. 95197068.2 of Chinese patent " a kind of composite material containing airgel, its Preparation method and application", No. 96196879.6 "Composite material containing airgel and adhesive, its preparation method and application"), due to the addition of adhesive, although the strength of the material has been improved to a certain extent, the airgel The high-efficiency thermal insulation effect of the material is difficult to guarantee; (2) The material formed by adding an inorganic reinforcing agent (short fiber) and an infrared opacifying agent (titanium dioxide) in the sol process to form a gel and then dried by a supercritical fluid (see Chinese patent No. 97106652.3 "Modified Nano Thermal Insulation Material and Its Production Process"), its infrared opacifier is difficult to disperse evenly, and its mechanical strength is still difficult to meet the requirements of harsh environments; (3) Fiber is used as a reinforcing phase and a sol-gel process is used 1. Supercritical fluid drying process forms airgel composite material (referring to U.S. Patent No. US6068882), and described material has good thermal insulation effect and service performance, but the process comparison of depositing molecular carbon or metal on the fiber surface reduces infrared transparency Complicated; in addition, the hydrophobicity of the made material is poor, and the thermal insulation effect will be reduced due to water absorption during actual use