Muti-wall carbon nanotubes (MWCNTs) were functionalized by grafting polyimide (PI) on their surface via Friedel-Crafts acylation. The functionalized MWCNTs (f-MWCNTs) showd less damages than unfunctionalized ones. The partially imidized polyamide acid as-spun fibers containing f-MWCNTs were prepared by wet spinning, and the final PI/f-MWCNTs composite fibers were obtained by heat treatment. The tensile strength of the PI based composite fiber containing 1.0 wt% f-MWCNTs was 818.3 MPa and the Young’s modulus was 9.26 GPa, which were about 81% and 88% higher than those of pure PI fiber, respectively. Besides, the thermal stability of PI/f-MWCNTs composite fibers was obviously improved.
EFFECT OF HEAT-TREATMENT AND DRAWING ON VOIDS IN NYLON 6 WET SPINNING FIBERS