Porous polyetherimide fiber fabricated by a facile micro-extrusion foaming for high temperature thermal insulation

• Published in: Journal of CO2 utilization Vol. 65; p. 102247
• Main Authors: Zhou, Mengnan, Li, Mengya, Jiang, Junjie, Li, Yaozong, Liu, Huawen, Chen, Bichi, Zhao, Dan, Zhai, Wentao
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.11.2022
• Subjects: CO2 blowing agent; Micro-extrusion foaming; Porous polyetherimide fiber; Thermal insulation; CO2 blowing agent; Porous polyetherimide fiber; Micro-extrusion foaming; Thermal insulation
• ISSN: 2212-9820; 2212-9839
• DOI: 10.1016/j.jcou.2022.102247

In this work, we reported a novel micro-extrusion foaming process using CO2 as a physical foaming agent to fabricate porous polyetherimide (PEI) fibers with open-cell skin and submicrocellular core. A high cell nucleation rate was triggered due to a high gas solubility during the temperature-rise foaming process within the extrusion head. The time-limited cell growth and cell coalescence with foaming time less than 3.95 s were the fundamental reasons for the fabrication of porous PEI fibers with submicrocellular size of about 550 nm. The thermal insulation properties of porous PEI fibers and their textiles woven were investigated, and the submicrocellular structure improved the thermal insulation properties, and resulted in the highest temperature difference of 40.6 °C. The flame retardancy and the superhydrophobic modification of porous PEI fibers were also confirmed. Our research results on the correlation between the characterization and functions of porous PEI fibers are expected to promote the development and application of thermal insulation porous polymer fibers. [Display omitted] •Porous PEI fiber with open-cell skin and submicrocellular core was fabricated by micro-extrusion foaming process.•Continuous porous fibers can be obtained only when the filament feed rate was in the range of 1.4–4.3 mm/s.•Time-limited cell growth and coalescence are the reasons for the realization of submicrocellular structure.•The best thermal insulation property was obtained when cell size was 550 nm.•Low thermal conductivity is the reason for the thermal insulation properties of submicrocellular structure.