Styrene-butadiene-styrene-based stretchable electrospun nanofibers by carbon nanotube inclusion

The state-of-the-art organic composite nanofibers have certain advantages over their metal-oxide counterparts because of mechanical flexibility, lightweightness and electrical conductivity. This study focuses on the synthesis of a novel styrene-butadiene-styrene (SBS) copolymer blended with polystyrene (PStyr) and carbon nanotubes (CNTs), and its properties are compared with CNT-free versions as well as with polystyrene-polybutadiene blends. The semi-crystallinity of SBS/PStyr disappears with the inclusion of CNTs of 1.25 wt%, indicating that even small quantities of CNTs retard the crystallization process. In Fourier transform infrared spectroscopy, the included CNTs reveal themselves by the decreased absorbance of both SBS/PStyr and PStyr/PBu. On the other hand, for Raman spectroscopy, this intensity drop is only recognizable in PStyr/PBu, where the interaction of CNTs with PStyr and PBu was limited in samples with SBS. PStyr/PBu/CNT has a non-porous and rough texture, and it is relatively denser with a mean fiber diameter of 0.66 mu m compared to its CNT-free counterpart. The glass transition (Tg) of the PBu peak is determined to be changing between -96 and -72 degrees C, whereas the Tg of polystyrene is not majorly influenced by copolymerization nor by CNT addition. The observed changes are accounted for by the increase in C1s sp(2) and decrease in C1s C-O, C=O and O=C=O peaks upon CNT addition, particularly for SBS/PStyr.