Enhanced tensile strength and electrical conductivity of electrospun polyacrylonitrile Yarns via post‐treatment

Abstract

In this study, electrically conductive polyacrylonitrile (PAN) yarn structures functionalized with multi‐walled carbon nanotubes (MWNTs) were obtained in one single step using modified electrospinning setup. Typically, to obtain fiber yarns, the fibers are directly deposited on the surface of the water and drawn out using a mechanical roller. In our setup, the water bath was replaced with an aqueous dispersion of MWNTs. The PAN fibers were drawn out of the MWNT dispersion bath and were found to have MWNTs non‐covalently coated on their surfaces. The electrical conductivity of these fibers were measured to be 0.28 S/m. Known amount of dimethyl formamide was also added to the aqueous dispersion of MWNTs to improve fiber density and fiber‐to‐fiber interaction within the yarns. A mechanical drawing process was later applied at temperature above PAN's glass transition temperature to strengthen and stiffen the yarn structures. The tensile strength and modulus increased with the drawing ratio and was seen to improve by 600 and 690%, respectively. POLYM. COMPOS., 40:1702–1707, 2019. © 2018 Society of Plastics Engineers