Functionalized multi-wall carbon nanotube reinforced poly(ester-imide) bionanocomposites containing L-leucine amino acid units

Abstract

This study aims at characterizing the thermal and morphological properties of multi-walled carbon nanotubes (MWCNT)s reinforced poly(ester-imide) (PEI) bionanocomposites (BNC)s containing amino acid group which were prepared through ultrasonication technique. To enhance the interfacial interaction between MWCNTs and PEI, carboxylic functionalized MWCNTs were embedded with PEI chains. By applying a step-growth polymerization method, biodegradable and chiral PEI was synthesized from a reaction of natural amino acid based diacid (4) with 4,4′-thiobis(2-tert-butyl-5-methylphenol) (5) promoted by tosyl chloride in pyridine and N,N-dimethyl formamide solution. The prepared BNCs were studied with Fourier transform infrared spectroscopy, X-ray diffraction, field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM) and thermogravimetric analysis (TGA). The microstructure study of the BNCs containing 5, 10, and 15 wt.% MWCNT–COOH exhibited rather homogeneous dispersion of MWCNTs throughout PEI matrices on the macroscopic scale. In comparison with neat PEI, the MWCNTs reinforced BNCs revealed higher thermal stability as confirmed by TGA results.