气凝胶
材料科学
复合材料
聚氨酯
超临界干燥
超临界流体
多孔性
热的
弹性模量
甲基三甲氧基硅烷
化学
物理
有机化学
气象学
涂层
作者
Beatriz Merillas,Alyne Lamy-Mendes,Fernando Villafañe,Luísa Durães,Miguel Ángel Rodríguez‐Pérez
出处
期刊:Gels
[MDPI AG]
日期:2022-06-21
卷期号:8 (7): 392-392
被引量:15
摘要
In this work, silica aerogel composites reinforced with reticulated polyurethane (PU) foams have been manufactured having densities in the range from 117 to 266 kg/m3 and porosities between 85.7 and 92.3%. Two different drying processes were employed (ambient pressure drying and supercritical drying) and a surface modification step was applied to some of the silica formulations. These composites, together with the reference PU foam and the monolithic silica aerogels, were fully characterized in terms of their textural properties, mechanical properties and thermal conductivities. The surface modification with hexamethyldisilazane (HMDZ) proved to improve the cohesion between the reticulated foam and the silica aerogels, giving rise to a continuous network of aerogel reinforced by a polyurethane porous structure. The samples dried under supercritical conditions showed the best interaction between matrixes as well as mechanical and insulating properties. These samples present better mechanical properties than the monolithic aerogels having a higher elastic modulus (from 130 to 450 kPa), a really exceptional flexibility and resilience, and the capacity of being deformed without breaking. Moreover, these silica aerogel-polyurethane foam (Sil-PU) composites showed an excellent insulating capacity, reaching thermal conductivities as low as 14 mW/(m·K).
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