Effect of tungsten disulfide (WS_2) nanotubes on structural, morphological and mechanical properties of poly(L-lactide) (PLLA) films

Poly(L-lactide) (PLLA) is a semicrystalline, biocompatible and biodegradable polymer widely employed in many applications (food packaging, biomedical devices, drug delivery systems). This work deals with nanocomposites of PLLA and tungsten disulfide (WS_2) nanotubes (NTs) as a novel material to obtain thinner and stronger bioresorbable vascular scaffolds. We studied the influence of WS_2 NTs on the mechanical properties of PLLA-WS_2 films. Polarized optical microscopy reveals a high degree of orientation of the polymer molecules in stretched films that further increases with a post-stretching annealing treatment. At the same time, X-ray diffraction (XRD) and Raman spectroscopy confirm enhancement of the crystallinity induced by the WS_2 NTs.