Effect of surface funcionalized carbon nanotubes on the morphology, as well as thermal, thermomechanical, and crystallization properties of polyactide

Abstract

This paper discusses various properties of Poly(lactide) upon nanocomposite formation with functionalized multiwalled carbon nanotubes (f-MWCNTs). The composite was prepared through melt extrusion technique. Functionalization of carbon nanotubes and possible interaction with PLA chains was investigated through attenuated total reflectance (ATR) Fourier transformed-infrared (FT-IR) and Raman spectroscopies. Scanning electron microscope (SEM) and polarized optical microscope (POM- in melt state) also revealed homogenous dispersion of f-MWCNTs in the PLA matrix with some agglomerates. Melting and crystallization phenomena of the nanocomposite studied through differential scanning calorimeter (DSC), wide angle X-ray scattering (WAXS), and POM show that f-MWCNTs facilitates nucleation and crystal growth of PLA matrix significantly. Thermogravimetric analyses (TGA) reveal that overall thermal stability of PLA matrix improves slightly upon the nanocomposite formation. Thermomechanical analyses also reveal a significant increase in modulus of the nanocomposite at room temperature, which drops suddenly across glass transition temperature. This is an indication of plasticization effect.