Publication

Abstract : This study reports carbonization of electrospun polyimide nanofiber webs reinforced with acid-functionalized multiwalled carbon nanotubes, and the effect of carbonization and CNTreinforcements on their electrical conductivity. Pyromellitic dianhydride (PMDA), 4,4 -Oxydianiline (ODA) and 4,4 -(4,4 -isopropylidene diphenyl-1,1 -diyl dioxy) dianiline (IDDA) were copolymerized in Dimethyl formamide (DMF) solvent to form a viscous poly (amic acid) (PAA) solution. The PAA solutions were prepared with incorporation of acid functionalized MWCNTs (0, 1 and 2 wt%). The PAA solution was electrospun into nanofiber web and was heated up to 300 C for imidization to form polyimide (PI) nanofiber web. In this study, radio-frequency induction heating method was utilized to carbonize the nanofiber web by heat treatment at 900 and 1000 C under nitrogen atmosphere and the yield decreased from 54% at 900 C to 51% at 1000 C. The carbonized nanofiber (CNF) webs were characterized by Fourier Transform Infrared spectroscopy, Raman spectroscopy, X-ray diffractometer and scanning electron microscopy. The tensile strength of PI/f-MWCNT (2 wt%) nanofiber web increased twice of neat PI nanofiber web. The electrical conductivity of CNF webs increased mildly with increasing heat treatment temperature, viz., 2.21 and 2.28 S/cm, for CNF at 900 and 1000 C respectively. This conductivity increased to 5.73 and 16.90 S/cm for CNF with 1% f-MWCNT and CNF 2% f-MWCNT at 1000 C respectively. Keywords:nbsp;