Synergistic effect of Mn2+ with unzipped carbon nanotubes on enhancement of mechanical properties of polyamide 66

Multi-walled carbon nanotubes (MWCNTs) are widely recognized for their exceptional mechanical properties and potential to reinforce composite materials. However, the requirement for high MWCNT concentration remains a challenge in achieving effective reinforcement. In this study, using unzipped multi-walled carbon nanotubes (uMWCNTs) and transition metal filler as a means to significantly enhance the mechanical properties of polyamide 66 (PA66) and incorporating 0.2% w/w of uMWCNTs-Mn as filler allowed us to increase PA66's tensile strength by over 74% and its Young's modulus by over 100%. The structural and functional integrity of uMWCNTs-Mn and PA66 matrix were investigated in detail. This work reveals that the enhancement of mechanical properties is mainly due to the interfacial interaction between uMWCNTs-Mn sheets and the PA66 matrix, the coupling effect of manganese ions, and increases the crystallinity and reduces the size of microcrystals. This work's findings provide a novel approach to the preparation of high-performance composites with low concentrations of carbon nanostructures, which holds significant implications for the development of advanced materials. (c) 2023 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).