Preparation and characterization of functionalized multiwalled carbon nanotubes filled polyethylene oxide nanocomposites

Abstract

The functionalized multi-walled carbon nanotubes (F-MWCNTs) filled polyethylene oxide (PEO) nanocomposites were prepared by casting technique and characterized by scanning electron microscopy (SEM), polarized optical microscopy (POM), thermal gravimetric analysis (TGA) and differential thermal analysis (DTA). The MWCNTs were functionalized by Friedel–Crafts acylation, which introduced aromatic amine groups on the side wall of nanotubes. The SEM micrograph of F-MWCNTs/PEO nanocomposites fractured surfaces indicated that the F-MWCNTs were well dispersed within the PEO matrix. The POM study presented that the neat PEO upon crystallization showed considerable size of crystalline spherulites. The sizes of spherulites decreased with incorporation of F-MWCNTs into the polymer matrix, which might be due to the nucleation role of F-MWCNTs in F-MWCNTs/PEO composite. The DSC analysis showed that the Tm of pure PEO was about 66 °C, which slightly decreased by the incorporation of F-MWCNTs into the polymer matrix. The Tm of 1, 3 and 5 wt% F-MWCNTs/PEO nanocomposites was 65.6, 64 and 63.8 °C, respectively. It was also observed that the thermal stabilities of pure PEO were shifted towards higher temperature when F-MWCNTs were incorporated into the polymer matrix. The TGA analysis represents that pure PEO and 1 wt% of F-MWCNTs/PEO nanocomposite decomposed completely at about 460 °C while thermal stability of 3 and 5 wt% of F-MWCNTs/PEO nanocomposites were shifted towards higher temperature.