Vitamin C functionalized multi-walled carbon nanotubes and its reinforcement on poly(ester-imide) nanocomposites containing L-isoleucine amino acid moiety

Abstract

The aim of this research was to prepare poly(ester–imide) (PEI)-based nanocomposites (NCs) through the functionalization of carboxylated-multiwalled carbon nanotubes (MWCNT)s with ascorbic acid, in order to ensure better filler dispersion and good interfacial adhesion between filler and matrix. Chiral and biodegradable PEI was synthesized from amino acid-based diacid with 4,4′-thiobis(2-tert-butyl-5-methylphenol) by a direct polycondensation method. Using the solution mixing technique, the NCs containing modified MWCNTs with different loading levels of 5,10, 15 wt% were produced and examined in terms of chemical structure, morphology, and thermal stability by FT-IR spectroscopy, thermogravimetric analysis (TGA), X-ray diffraction, transmission electron microscopy (TEM), and field emission scanning electron microscopy (FE-SEM). TEM and FE-SEM photographs of the obtained NCs indicated well-dispersed morphologies and strong interaction between the functionalized MWCNTs and the polymer matrix. TGA results revealed that the addition of MWCNT resulted in a significant increase of the thermal stability and char yields of the NCs compared to those of the neat PEI.

• Keywords
• Polymer nanocomposites
• poly(ester–imide)
• functionalized multi-walled carbon nanotubes
• ultrasonic irradiation
• vitamin C

Acknowledgments

The authors wish to express our gratitude to the Research Affairs Division Isfahan University of Technology (IUT), Isfahan, for partial financial support. Further financial support from National Elite Foundation (NEF), Iran Nanotechnology Initiative Council (INIC) and Center of Excellence in Sensors and Green Chemistry Research (IUT) is gratefully acknowledged.