Fabrication and Characterization of a High-Strength Polyimide/Thermoplastic Polyurethane Composite Aerogel with Hydrophobicity and Low Thermal Conductivity

• Published in: Langmuir Vol. 39; no. 28; pp. 9693 - 9702
• Main Authors: Nie, Yihao, Yi, Xibin, Zhao, Xinfu, Yu, Shimo, Zhang, Minna, Zhang, Jian, Dou, Guoliang, Wang, Mengdi
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 18.07.2023
• ISSN: 0743-7463; 1520-5827
• DOI: 10.1021/acs.langmuir.3c00664

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/cm3) 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–1 K–1 at ambient temperature. Therefore, PI/TPU composite aerogel can be a promising material for hydrophobic and thermal insulation applications.