Preparation of R-BABP Polyimide Fibers via Wet Spinning of Polyamide Acid

Abstract

A polyamide acid (PAA) based on diamine 4,4'-bis (4-aminophenoxy) diphenyl and 1,3-bis (3',4-dicarboxyphenoxy) benzene dianhydride was synthesized. PAA fibers were obtained by wet spinning. Then, these fibers were converted into polyimide by thermal imidization. Dependence of the structure and properties of fibers on the die drawing and the composition of the coagulation bath was studied. It is shown that the composition of the coagulation bath has a significant effect on the morphology and mechanical properties of polyimide (PI) fibers. To obtain defect-free fibers, a coagulation bath consisting of ethylene glycol/ethanol at 50/50 vol. % was found to be optimal. An increase in the die drawing of fibers from 1 to 2 times leads to an increase in tensile strength and strain at break of the polyimide fibers.

Investigation of Polyetherimide Melt-Extruded Fibers Modified by Carbon Nanoparticles

“…Dry spinning involves passing a solution of polyimide or its prepolymer through a spinneret and blowing hot air on the forming fiber to remove the solvent, followed by heat treatment [ 11 ]. In wet spinning, the solution is passed through a coagulation bath with a precipitant in which the solvent is removed and the prepolymer is precipitated in the form of a fiber [ 12 ]. Finally, melt-spun fibers are produced by extrusion and drawing the finished PI above its melting point [ 13 ].…”