Fabrication and Comparative Study of Large‐Diameter Multi‐Walled Carbon Nanotubes Filled Chitosan, Epoxy, and Polypropylene Composites

Abstract

This study presents a systematic comparative investigation of large-diameter (100–110 nm) multi-walled carbon nanotube (MWCNT) reinforced composites utilizing three structurally distinct polymer matrices: chitosan (CS), epoxy (EP), and polypropylene (PP). Synthesized via aerosol-assisted chemical vapor deposition, the MWCNTs were incorporated at concentrations ranging from 0.5 to 3 wt.%. The composite properties were evaluated through a comprehensive suite of analytical techniques, including SEM for morphology, FTIR and Raman spectroscopy for structural/chemical characterization, thermogravimetric analysis for thermal stability, laser flash analysis for thermal conductivity, and detailed DC/AC electrical characterization to assess charge transport dynamics. Experimental results demonstrate that the percolation threshold lies at approximately 1.0 wt.% for the EP and PP systems, while the CS-based composite exhibits enhanced charge transport at this concentration. At 3 wt.% loading, all composites demonstrate ohmic, quasi-metallic behavior. While all composites achieve a robust percolative network at 3 wt.% filler loading, the AC electrical characterization highlights distinct matrix-dependent charge transport dynamics. These findings underscore the critical role of polymer-filler interfacial interactions in governing functionality, positioning the MWCNT/CS composite as a promising candidate for eco-friendly biomedical interfaces and advanced flexible electronics.