Aerogels based on organic high performance fibers have been attracted great attention due to its excellent thermal and mechanical properties. Here, PBO nanofiber aerogel were prepared from the super-fiber PBO through a top-down process with a sol-gel process and a simple freeze-drying process, followed by thermal cross-linking. The prepared aerogel has a small volume shrinkage, a high specific surface area of 168.9 m2 /g and a small pore diameter of 1.356 nm. Because of its 3D porous structure, it results in a low density of 6 to 30 mg/cm3 and a high porosity (98%). The aerogel retains the molecular structure of PBO at the same time, which gives it initial thermal decomposition temperature up to 500 °C and a superior fire-retardant capability. PBO aerogel possesses good compressive properties with a yield stress of 0.44MPa at 80% strain and an elasticity modulus of 1.98 MPa which is higher than SiO2 and cellulose aerogel reported.
