CPC D01D 5/247 (2013.01) [D01D 1/02 (2013.01); D01F 1/07 (2013.01); D01F 6/82 (2013.01); D03D 15/513 (2021.01); D03D 15/52 (2021.01)] | 4 Claims |
1. A method of fabricating a fiber which is thermal-insulating at high temperature and fire-retardant, comprising:
(1) using a poly(amic acid) hydrogel for spinning, performing a directional freezing process during spinning, and collecting the frozen fiber, wherein the directional freezing process includes: the poly(amic acid) hydrogel passing through a freezing copper ring after being extruded from an extruder and water is frozen directionally in a direction of a temperature gradient under a temperature field;
(2) freeze-drying the frozen fiber to remove ice crystal and then obtain a fiber with aligned porous structure; and
(3) heating the fiber to realize a thermal imidization of poly(amic acid) into polyimide,
wherein the fiber is a polyimide porous fiber with an aligned and continuous through-hole along an axial direction.
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