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 μm compared to its CNT-free counterpart. The glass transition (T_g) of the PBu peak is determined to be changing between ?96 and ?72 °C, whereas the T_g of polystyrene is not majorly influenced by copolymerization nor by CNT addition. The observed changes are accounted for by the increase in C1s sp² and decrease in C1s C–O, CO and OCO peaks upon CNT addition, particularly for SBS/PStyr.