Microextrusion Foaming of Polyetheretherketone Fiber: Mechanical and Thermal Insulation Properties

Porous polyetheretherketone (PEEK) materials, especially those with controllability and excellent mechanical properties, have always been the development hotspots in the fields of thermal insulation and medical bone implants. However, the traditional sulfonation process of porous PEEK materials has the problems of applying abundant high‐concentration solvents, high production costs, low resource utilization, and environmental pollution. Herein, a microextrusion foaming process with using CO₂ as a blowing agent is proposed for creating porous PEEK fibers under different parameters. The as‐prepared porous PEEK fiber possesses well‐defined cell morphology, high toughness (136.2%), and excellent thermal insulation properties (13.4 ± 1.50 °C), resulting from the high cell nucleation rate and limited‐time cell growth (<0.85 s). All in all, the microextrusion foaming process provides unprecedented opportunities for continuous manufacturing and functional development of porous PEEK fibers.