Enhancing the electrical conductivity of TPU-TPU/SWCNT multilayered composites using melt multipliers

Structuring and confining polymer layers have a profound influence on material properties and has been studied as means to achieving tailored and multifunctional materials. In this work, single-walled carbon nanotubes (SWCNT) are incorporated into thermoplastic polyurethane (TPU) using melt-mixing techniques. An electrical percolation threshold at 0.6 wt.% SWCNT is achieved for melt-extruded filaments after pre-dispersing SWCNT in polypropylene glycol. Additionally, a prototype device composed of a series of small-scale layer multipliers is developed. The application of the baker’s transformation enabled the extrusion of tapes with alternating layers of two different melts, TPU and composite TPU with SWCNT. These layered structures, obtained using an increasing number of melt multipliers, are characterized in terms of morphology, mechanical, and electrical properties. We demonstrate that layered tapes of TPU with TPU/SWCNT preserve the electrical conductivity of the TPU/SWCNT composite, at half SWCNT weight percentage, and the ductility of neat TPU. • Melt-extruded TPU composite is electrically conductive at 0.6 wt% of SWCNT content. • Small-scale multipliers are used to obtain alternating TPU/composite layered tapes. • Produced tapes are electrically conductive with 0.3 wt% SWCNT. • The ductility of TPU is kept in the layered composite tapes.