Advanced Materials Institute, Qilu University of Technology (Shandong Academy of Sciences), Jinan, Shandong 250014, People's Republic of China.
Shandong Copolymer Silicone Technology Research Institute, Weifang, Shandong 261000, People's Republic of China.
Langmuir. 2023 Jul 18;39(28):9693-9702. doi: 10.1021/acs.langmuir.3c00664. Epub 2023 Jul 6.
Polyimide (PI) aerogel has surfaced in research and development as a result of its heat resistance, flame retardancy, and low dielectric constant. However, it is still a challenge to reduce the thermal conductivity while improving its mechanical strength and retaining hydrophobicity. Herein, the PI/thermoplastic polyurethane (TPU) composite aerogel was synthesized by coupling TPU with PI via a novel method of chemical imidization combined with freeze-drying technology. With this technique, PI aerogel with excellent comprehensive performance is produced. Interestingly, the volume shrinkage of the composite aerogel decreased from 24.14 to 5.47%, which leads to low density (0.095 g/cm) and elevated porosity (92.4%). In addition, strong mechanical strength (1.29 MPa) and high hydrophobicity (123.6°) were achieved. More importantly, PI/TPU composite aerogel demonstrated a low thermal conductivity of 29.51 mW m K at ambient temperature. Therefore, PI/TPU composite aerogel can be a promising material for hydrophobic and thermal insulation applications.
聚酰亚胺（PI）气凝胶因其耐热性、阻燃性和低介电常数而在研究和开发中崭露头角。然而，在提高机械强度和保持疏水性的同时降低热导率仍然是一个挑战。在此，通过一种新颖的化学亚胺化方法结合冷冻干燥技术，将热塑性聚氨酯（TPU）与 PI 偶联，合成了 PI/TPU 复合气凝胶。采用该技术，可制备出具有优异综合性能的 PI 气凝胶。有趣的是，复合气凝胶的体积收缩率从 24.14%降至 5.47%，从而实现了低密度（0.095 g/cm）和高孔隙率（92.4%）。此外，还获得了较高的机械强度（1.29 MPa）和疏水性（123.6°）。更重要的是，PI/TPU 复合气凝胶在环境温度下表现出 29.51 mW m K 的低热导率。因此，PI/TPU 复合气凝胶有望成为一种用于疏水性和隔热应用的材料。
