Electric conductive fibers from extrinsic conductive fillers with thermoplastics by melt spinning

The aim of this review is to identify the literature for the scientific work to understand the basics of the conduction mechanism of electrically conductive filament yarns made from extrinsic con-ductive fillers and thermoplastic polymer using melt spinning. In recent years, extrinsic conductive fillers have become very popular due to their electrical conductivity and have received greater research attention. In general, extrinsic conductive fillers are carbon-based conductive materials. These include carbon black (CB), carbon nanotubes (CNT), graphene and graphite. This thematic review mainly focuses on the thermal, mechanical and electrical properties of melt-spun thermoplastic polymers, such as polypropylene, polyamide, poly(ethylene terephthalate), thermoplastic polyurethane, polycarbonate, polyimide, poly(methyl methacrylate and poly(L-lactide)) acid with CB, CNT, graphene and graphite. The structure, shape, size and properties of extrinsic conductive fillers are described in this review. The development of electrically conductive filament yarns from extrinsic conductive fillers using the melt spinning process requires a consideration of the entire process, from pre-treatment, compounding and melt spinning of the extrinsic conductive fillers to the drawing of the electrically conductive filament yarn. In order to achieve better spinnability of the two different components (conductive filler, thermoplastic polymer), an overview of the pretreatment methods of the extrinsic conductive filler and thermoplastic polymers is given. Mixing of inorganic nanomaterials into a polymer matrix involves many challenges, like agglomeration, poor dispersion and scattering of the extrinsic conductive filler within the thermoplastic polymer. Therefore, the most important influencing factors of the melt spinning process are discussed in detail in this review. Depending on the type of polymer (amorphous, crystalline, semi-crystalline), extrinsically conductive fillers can influence the crystallization process in different ways. The textile mechanical and electrical properties of the spun extrinsically conductive yarn will be comprehensively highlighted. Finally, new developments in the field of conductive filament yarns are presented