Polyamide-grafted-multi-walled carbon nanotube electrospun nanofibers/epoxy composites

Multi-walled carbon nanotubes were grafted by polyamide via Friedel-Crafts acylation and in-situ polymerization routes using gamma-Phenyl-epsilon-caprolactone to obtain MWCNT-PA. Poly(azo-naphthyl-imide) (PI) was also prepared in this work. Afterward, electrospun nanofibers were prepared using grafted nanocarbon fibers in two different polymers; polyimide (PI) and PI/polyaniline (PANI). The obtained nanofibers were used to reinforce an epoxy resin. Scanning and transmission electron microscopy revealed fibrous nature of these composites. The tensile modulus of epoxy composites reinforced by electrospun PI/PANI nanofibers (25.3 GPa) was considerably higher than PI nanofibers (19.8 GPa). In addition, thermal stability of PI/PANI nanofiber composites was superior as having 10 % gravimetric loss at 623-671 A degrees C and glass transition temperature of 289-297 A degrees C relative to MWCNT-PA/PI nanofiber-based system. The addition of 1 to 3 wt% MWCNT-PA/PI/PANI filler content enhanced the electrical conductivity of DGEBA/MWCNT-PA/PI/PANI from 3.33 to 5.99 S cm(-1).