Scalable fabrication of cross-linked porous centrifugally spun polyimide fibers for thermal insulation application

Abstract

Flexible fibrous thermal insulators with low thermal conductivity are highly demanded to improve energy efficiency in many application fields, especially in the aerospace industry. In the present study, the cross-linked porous polyimide (PI) fibrous insulator was prepared using centrifugal spinning, a scalable and facile technique for fibers production. The influence of PI concentration and solvent composition was evaluated to find the optimum parameters for defect-free fiber fabrication. In the following step, the PI fibers were cross-linked to gain better solvent stability. The morphology, chemical properties, surface wettability, thermal resistance, and thermal conductivity of the obtained fibers were evaluated. The cross-linked fibers exhibit a low thermal conductivity of 0.029 W/mK with thermal stability up to 515 °C, hydrophobicity with a contact angle of 137.7°, and are flexible at high temperature. The successful fabrication of the PI fibers opens a new approach for the scalable fabrication of flexible fibrous insulators for aerospace applications.