Ohio Aerospace Institute, 22800 Cedar Point Road, Cleveland, Ohio, USA.
ACS Appl Mater Interfaces. 2011 Feb;3(2):546-52. doi: 10.1021/am101123h. Epub 2011 Feb 4.
We report the first synthesis of polyimide aerogels cross-linked through a polyhedral oligomeric silsesquioxane, octa(aminophenyl)silsesquioxane (OAPS). Gels formed from polyamic acid solutions of 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA), bisaniline-p-xylidene (BAX) and OAPS were chemically imidized and dried using supercritical CO(2) extraction to give aerogels having density around 0.1 g/cm(3). The aerogels are greater than 90 % porous, have high surface areas (230 to 280 m(2)/g) and low thermal conductivity (14 mW/m-K at room temperature). Notably, the polyimide aerogels cross-linked with OAPS have higher modulus than polymer reinforced silica aerogels of similar density and can be fabricated as both monoliths and thin films. Thin films of the aerogel are flexible and foldable making them an ideal insulation for space suits, and inflatable structures for habitats or decelerators for planetary re-entry, as well as more down to earth applications.
我们报告了首例通过八聚倍半硅氧烷（OAPS）交联的聚酰亚胺气凝胶的合成。凝胶由 3,3',4,4'-联苯四羧酸二酐（BPDA）、双苯胺-对-二甲叉苯（BAX）和 OAPS 的聚酰胺酸溶液形成，经过化学亚胺化并使用超临界 CO2 萃取干燥，得到密度约为 0.1 g/cm3 的气凝胶。这些气凝胶具有大于 90%的多孔性、高比表面积（230 至 280 m2/g）和低导热系数（室温下为 14 mW/m-K）。值得注意的是，用 OAPS 交联的聚酰亚胺气凝胶的模量高于具有相似密度的聚合物增强二氧化硅气凝胶，并且可以制成块状和薄膜。气凝胶的薄膜具有柔韧性和可折叠性，使其成为航天服的理想隔热材料，以及可充气结构或行星再入减速装置，以及更实际的应用。
