Lightweight, flexible, and heat‐insulated phenolic impregnated carbon ablator (PICA) with adjustable flexibility and high compressive resilience property.

Phenolic impregnated carbon ablator (PICA) as a typical lightweight ceramic ablative material is widely used in thermal protection systems (TPS). However, the rigidity and poor mechanical property of the existing PICA limit its application in flexible TPS. For the purpose of solving these problems, a novel lightweight, flexible, and heat‐insulated PICA material is first successfully fabricated using resorcinol‐formaldehyde (RF) aerogel as matrix and flexible carbon fiber felt as reinforcement through vacuum impregnating and ambient pressure drying. The prepared composites have relatively low densities (0.20 ~ 0.27 g/cm3) and low thermal conductivities (~0.11 W/[m·K]) at room temperature. The flexible PICA has adjustable flexibility through changing the RF concentration of impregnated sols and exhibits excellent folding endurance, which can be folded more than 500 times without fracture. The material can recover to its original shape without fracture when the compressive strain is up to 60%, which shows high compressive resilience properties. The result of the back‐face temperature test indicates the prepared flexible PICA composite has improved thermal insulation property at high temperature by impregnating with RF aerogels. These results demonstrate the flexible PICA prepared in this work is a promising material that can be used in the flexible thermal protection field of aerospace. [ABSTRACT FROM AUTHOR]