Method for preparing aerogel fibrofelt through secondary compounding

Abstract

The invention provides a method for preparing aerogel fibrofelt through secondary compounding. The method comprises the following steps: removing a surface treating agent of the fibrofelt through heattreatment, and then performing hydrophobic modification on the surface of the fibrofelt by using a silane coupling agent; packaging other side surfaces, except one side surface, of the pretreated fibrofelt, thus aerogel slurry being unable to enter and exit from the internal pores of the fibrofelt through the packaged side surfaces; filling the aerogel slurry prepared from aerogel powder into thepackaged fibrofelt in a grading mode through vacuum infusion; and finally packaging the unpackaged surface of the fibrofelt, thus the aerogel slurry being unable to enter and exit from the internal pores of the fibrofelt. According to the method, the preparation process is simple, expensive production equipment is not needed, the cost is low, and the performance of the prepared aerogel fibrofeltcan rival that of an in-situ synthesis method; therefore, it is guaranteed that aerogel particles are fully filled in the fibrofelt, the aerogel powder can be prevented from falling off through surrounding resin packaging, and the obtained aerogel fibrofelt is excellent in performance.

Description

technical field [0001] The invention belongs to the technical field of airgel functional materials, and in particular relates to a method for preparing an airgel fiber mat through secondary compounding. Background technique [0002] Aerogel has the characteristics of extremely low density, high specific surface area, and high porosity. It is considered to be the best porous material for thermal insulation. However, the low strength of pure aerogel limits its application. Therefore, fiber-reinforced materials are usually used to strengthen aerogels to form airgel fiber mats to overcome the problem of poor aerogel strength and meet the requirements of use. [0003] At present, airgel fiber mat products mainly adopt the method of in-situ compounding. For example, in the preparation process of airgel fiber mat disclosed in patent CN105906298A, the airgel precursor needs to go through sol-gel reaction, solution graded replacement, surface Complex steps such as modification, atmo...

AI Technical Summary

Problems solved by technology

[0003] At present, airgel fiber mat products mainly adopt the method of in-situ compounding. For example, in the preparation process of airgel fiber mat disclosed in patent CN105906298A, the airgel precursor needs to go through sol-gel reaction, solution graded replacement, surface Complex steps such as modification, atmospheric pressure drying or supercritical drying generate airgel in situ inside the fiber mat, which has the disadvantages of complex process, long cycle and high cost.

In order to overcome the defects of the in-situ synthesis method, people try to prepare airgel fiber mats by secondary compounding (such as CN 107604634 A, CN 106757781A, CN 107574657 A and other patents). In the preparation method, airgel powder solutions with different particle sizes and fiber mats are mainly compounded by direct soaking, spraying, coating, etc. to obtain airgel fiber mats. These methods have simple processes and require simple equipment. It greatly reduces the production cost, and it is difficult to ensure that the airgel particles are completely filled inside the fiber mat, especially when the fiber mat is thicker, it is more difficult to fill and compound, so it is only suitable for the production of airgel ultra-thin fiber mat