Synthesis and properties of chiral poly(ester–imide)/multiwalled carbon nanotube nanocomposites containing 4,4′-thiobis(2-tert-butyl-5-methylphenol) and s-valine amino acid moieties
Chiral poly(ester–imide) (PEI) was synthesized from N-trimellitylimido-S-valine diacid with 4,4′-thiobis(2-tert-butyl-5-methylphenol) by a direct polycondensation method. S-Valine was covalently attached to carboxylated multiwalled carbon nanotubes (MWCNTs) and effectively dispersed in an aromatic polymer as a continuous medium to prepare PEI/MWCNT nanocomposites (NCs). X-ray diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy, and field-emission scanning electron microscopy were carried out to characterize the obtained NCs. The microstructural study of the NCs showed the homogeneous dispersion of MWCNTs throughout the polymer matrix. The results from thermal analysis indicated that the thermal stability of the NCs was improved, in comparison with that of pure PEI.