Facile and cost-effective strategy for fabrication of polyamide 6 wrapped multi-walled carbon nanotube via anionic melt polymerization of ε-caprolactam

There is a growing demand for the development of a melt process-based nanocomposite manufacturing process capable of minimizing the incorporation of expensive carbon nanotubes (CNTs)by inducing a uniform dispersion of multi-walled CNTs (MWNTs). In this study, we proposed a nanocomposite manufacturing process that includes both physical particle mixing using high-speed rotation and anionic polymerization of ε-caprolactam (CL)to induce a uniform dispersion of MWNTs. MWNTs were uniformly dispersed by powder mixing and then wrapped with polyamide 6 polymers by in-situ polymerization of CL. The synergistic effect of the two sub-processes resulted in an enhanced dispersion of MWNTs and prevented aggregation of the MWNTs. The composites fabricated by the proposed process exhibited electrical conductivities of 4.49 × 10⁻⁵ S/m and 1.45 × 10 S/m at 1 wt% and 3 wt% MWNTs, respectively, indicating that by applying the proposed process it is possible to incorporate a smaller amount of MWNT to achieve electrical conductivities applicable for electrostatic discharge (ESD)(>1 X 10⁻⁵ S/m)and electromagnetic interference shielding effectiveness (EMI SE)(>10 S/m)applications. An ESD chip tray and EMI SE mobile phone case were fabricated using the prepared composite, and it was verified that the ESD and EMI SE performances can be realized.