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

• Published in: European polymer journal Vol. 169; p. 111123
• Main Authors: Doan, Hoan Ngoc, Tagami, Shotaro, Vo, Phu Phong, Negoro, Masaki, Sakai, Wataru, Tsutsumi, Naoto, Kanamori, Kazuyoshi, Kinashi, Kenji
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 15-04-2022; Elsevier BV
• Subjects: Aerospace industry; Centrifugal spinning; Chemical properties; Contact angle; Cross-linking; Crosslinking; Fibers; Heat conductivity; Heat transfer; High temperature; Hydrophobicity; Insulation; Insulators; Polyimide; Porous materials; Solvents; Surface stability; Thermal conductivity; Thermal insulation; Thermal insulator; Thermal resistance; Thermal stability; Wettability; Polyimide; Centrifugal spinning; Cross-linking; Thermal insulator; Fibers
• ISSN: 0014-3057; 1873-1945
• DOI: 10.1016/j.eurpolymj.2022.111123

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•A facile and scalable preparation method of flexible polyimide fibrous thermal insulator was demonstrated.•The polymer concentration and solvent composition were optimized in order to fabricate fine fiber.•The cross-linked fibers exhibit better solvent stability compared to non-crosslink fibers.•The PI fibrous insulator shows low thermal conductivity and excellent flexibility at high temperature.
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.