High-strength flexible polysiloxane aerogel and preparation method thereof

Abstract

The invention provides a high-strength flexible polysiloxane aerogel material and a preparation method thereof. The method comprises the following steps of: firstly, synthesizing a linear flexible polysiloxane monomer, then taking polyalkoxy polyhedral oligomeric silsesquioxane as a cross-linking agent, changing the proportion of side groups in the polysiloxane monomer and the ratio of the polysiloxane monomer to the polyhedral oligomeric silsesquioxane cross-linking agent, and preparing a series of high-strength flexible super-hydrophobic polysiloxane aerogel materials by adopting a sol-gel method and normal-pressure drying. The preparation process is simple, the mechanical property is excellent, normal-pressure drying is adopted, the material is suitable for industrial large-scale production and can be applied to the fields of adsorbents, thermal insulation materials, thermal insulation materials and the like, and the preparation method and variety of the aerogel material are expanded.

Description

technical field [0001] The invention belongs to the field of airgel porous multi-material preparation, in particular to a preparation method of high-strength flexible superhydrophobic polysiloxane airgel. Background technique [0002] Aerosilica has attracted much attention in the past few decades due to its unique three-dimensional nanostructure. This special structure endows it with characteristics such as low density, high porosity, ultra-low thermal conductivity and high specific surface area, making it widely used in aerospace, capacitors, absorbents, heat insulation materials, sound insulation materials, phase change materials, adsorbents It has broad application prospects in the fields of catalyst support and so on. However, the nanoscale framework structure of aerosil leads to its fragile mechanical properties, which severely limits its practical applications. Therefore, improving the brittleness of silica airgel and improving its mechanical properties has become t...

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Problems solved by technology

[0003] At present, fiber or polymer is commonly used to reinforce silica airgel, but the size of the fiber is usually at the micron level or above, and there is a large scale difference with the nanoscale pore size of silica airgel, resulting in the uneven internal pore structure of the airgel, which is relatively large. Low surface area, poor mechanical properties

However, the use of polymers to strengthen silica aerogels, due to a certain degree of phase separation between the organic phase and the inorganic phase, will make the airgel pore structure uneven, and the polymer usually has a large molecular weight, which will cause the density of silica aerogels to increase. A substantial increase

[0004] The drying method of airgel usually adopts supercritical drying. Supercritical drying equipment is expensive and the control conditions are harsh, which is not conducive to large-scale industrial production.

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