Polyurea based aerogel for a high performance thermal insulation material

Cellulosic and Polyurethane Aerogels

“…lightweight and finely mesostructured materials with promising applications in thermal insulation [42]. At present, one of the remaining challenges in this field concerns their preparation through subcritical drying routes.…”

“…The most recent ones have been published by ASPEN in 2009 [42], and concern both polyurethane and polyurea aerogels. The sol-gel synthesis is performed directly in acetone with standard isocyanates and triethylamine (TEA) as catalyst used at a relatively high weight percent in solution (i.e., between 5 and 10 wt%).…”

“…Gels are typically dried with supercritical CO 2 . The article is mainly focused on the impact of the ratio between the amine hydrogen equivalent weight and the isocyanate equivalent weight (EW ratio) [42] on various properties of polyurea aerogels like gelation time, drying shrinkage, final density, porosity and thermal conductivity. A SEM image of a representative sample is shown in …”

Micromachining of polyurea aerogel using femtosecond laser pulses

“…The material shows hierarchical structures including an assembly of nanoparticles at the microscale. It is highly porous with a porosity of~85% and a mass density of~0.2 g/cm 3 .…”

“…Consequently, considerable efforts have been made to fabricate the nanostructured porous materials for various applications. However, it is difficult to cut these materials using traditional machining operations such as cutting, milling, and grinding due to their soft and porous nanoscale structures [2,3]. The recommended tool for cutting the aerogels is a diamond saw [2].…”