Role of Carboxylic Acid-Functionalized MWCNTs in Potentially Biodegradable Poly(Amide–Imide) Nanocomposites Based onN,N′-(Pyromellitoyl)-bis-S-valine: Preparation, Thermal and Morphological Properties

A simple solution-blending process was used to efficiently disperse of carboxyl-modified multiwalled carbon nanotubes into a potentially biodegradable poly(amide–imide) to obtain poly(amide–imide)/carboxyl-modified multiwalled carbon nanotubes bionanocomposites. Carboxyl-modified multiwalled carbon nanotubes were utilized to better dispersion of multiwalled carbon nanotubes into the polymer matrix. The poly(amide–imide)/carboxyl-modified multiwalled carbon nanotube bionanocomposites were prepared with different carboxyl-modified multiwalled carbon nanotube contents (5–15 wt%). The resulting bionanocomposites are characterized by several techniques, powder X-ray diffraction, scanning electron microscopy, transmission electron microscopy analysis, Fourier transform infrared spectroscopy, and thermogravimetric analysis. Adding carboxyl-modified multiwalled carbon nanotube into polymer matrix significantly increased the thermal stability of bionanocomposites due to the increased interfacial interaction between the poly(amide–imide) matrix and carboxyl-modified multiwalled carbon nanotube.