As a nanoporous material, polyimide (PI) aerogels have excellent thermal and acoustic properties. However, their high air flow resistance is detrimental to the development of their acoustic properties. To enhance the thermal and acoustic insulation properties of PI aerogels, we have selected hollow glass microbeads (HGM) with a low thermal conductivity coefficient to be combined with the PI aerogel, leading to the fabrication of PI/HGM aerogel composite materials. In this study, there are two preprocessing methods for HGM: untreated and aminized (HGM-NH). These were then individually combined with PI aerogel to fabricate two distinct PI/HGM composite aerogels: a physically blended variant (PIHGM) and a chemically bonded one (PHN). The thermal insulation and acoustic properties of these two composite aerogels were compared. The results show that HGM-NH not only functions as a cross-linking agent but also plays a key role in forming the three-dimensional network structure, which effectively reduces the shrinkage rate and density of the composite aerogel. Moreover, the thermal conductivity of PHN reached a low of 27.92 mW m⁻ K⁻, which is a reduction compared to PIHGM's thermal conductivity of 29.83 mW m⁻ K⁻. Moreover, the PHN composite aerogel with 10% HGM addition exhibited an average sound insulation level that was 120% higher than that of PIHGM. The method of incorporating pore structures with different scales also offers valuable insights for enhancing the sound insulation performance of other materials.

中文翻译：

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低收缩聚酰亚胺气凝胶与氨基功能化空心玻璃微珠交联，用于隔热和隔音

作为一种纳米多孔材料，聚酰亚胺（PI）气凝胶具有优异的热学和声学性能。然而，它们的高气流阻力不利于其声学特性的发展。为了提高PI气凝胶的隔热和隔音性能，我们选择了低导热系数的空心玻璃微珠（HGM）与PI气凝胶结合，从而制备了PI/HGM气凝胶复合材料。在本研究中，HGM 有两种预处理方法：未处理和氨化 (HGM-NH)。然后将它们单独与 PI 气凝胶组合，制造出两种不同的 PI/HGM 复合气凝胶：一种是物理混合气凝胶 (PIHGM) 和一种化学粘合气凝胶 (PHN)。比较了这两种复合气凝胶的隔热和声学性能。结果表明，HGM-NH不仅起到交联剂的作用，而且在形成三维网络结构方面发挥着关键作用，有效降低了复合气凝胶的收缩率和密度。此外，PHN的热导率达到了27.92 mW m-K-的低值，与PIHGM 29.83 mW m-K-的热导率相比有所降低。此外，添加10％HGM的PHN复合气凝胶的平均隔音水平比PIHGM高120％。结合不同尺度的孔隙结构的方法也为增强其他材料的隔音性能提供了宝贵的见解。