Abstract:Polyimide (PI) has attracted much attention due to its excellent comprehensive properties. The construction of high-strength aerogels by PI is of great significance for expanding its applications in high-tech fields such as aerospace, microelectronics, etc. In this work, 4,4'-oxydianiline (ODA) and 3,3',4,4'-benzophenone tetracarboxylic dianhydride (BTDA) were used as monomers to construct polyimide aerogels, and aramid nano fibers (ANFs) were introduced to enhance the skeleton of aerogels. The influences of ANFs on the chemical structure, microscopic morphology and mechanical properties of aerogels were explored through Fourier Infrared Spectroscopy (FT-IR) and Scanning Electron Microscopy (SEM). The results revealed that ANFs were combined with the precursor polyamic acid (PAA) through hydrogen bonding, and were evenly dispersed to enhance the aerogel skeleton effectively. It’s clear that the volume shrinkage rate during the aerogel preparation process effectively reduced with the introduction of ANFs. Compare to the pure PI aerogels, the volume shrinkage of aerogels with 4 wt% ANFs is reduced from 63% to 54%, the Young’s modulus increased from 1.8 MPa to 6.9 MPa, and the compression rebound rate increased by 37%.