Effect of Carboxylic Acid Group of Functionalized Carbon Nanotubes on Properties of Electrospun Polyacrylonitrile (PAN) Fibers

Abstract

To study the effects of the acid group of functionalized MWNT (multiwalled carbon nanotube) on the thermal and mechanical properties of polyacrylonitrile (PAN) nanofibers, acid (H2SO4/HNO3) treated MWNT (O-MWNT) were further functionalized by diazonium salt reaction with 5-aminoisophthalic acid (IPA). Compared to O-MWNT, IPA-MWNT with isophthalic acid group showed a better dispersion stability in polar solvents and IPA-MWNT/PAN composite film displayed lower heat of reaction (Delta H) than that of homo PAN when stabilized under air atmosphere. The continuous electrospun fibers were prepared using a conductive water bath. PAN fibers containing 1 wt% of IPA-MWNT showed an increase of tensile strength by 100% and tensile modulus by 240% compared to the PAN fibers without IPA-MWNT.