Effect of tungsten disulfide nanotubes on crystallization of polylactide under uniaxial deformation and annealing

Abstract

Tungsten disulfide (WS₂) nanotubes (NTs) are examined here as a filler for polylactide (PLA) for their ability to accelerate PLA crystallization and for their promising biocompatibility in relevant to biomedical applications of PLA-WS₂ nanocomposites. In this work, we have studied the structural and thermal properties of PLA-WS₂ nanocomposite films varying the concentration of WS₂ NTs from 0 (neat PLA) to 0.6 wt%. The films were uniaxially drawn at 90 °C and annealed at the same temperature for 3 and 10 min. Using wide angle x-ray scattering, Raman spectroscopy and differential scanning calorimetry, we probed the effects of WS₂ NT addition on the structure of the PLA films at various stages of processing (unstretched, stretching, annealing). We found that 0.6 wt% of WS₂ induces the same level of crystallinity in as stretched PLA-WS₂ as annealing in neat PLA for 10 min. These data provide useful insights into the role of WS₂ NTs on the structural evolution of PLA-WS₂ composites under uniaxial deformation, and extend their applicability to situations where fine tuning of PLA crystallinity is desirable.