WS2 inorganic nanotubes reinforced poly(L-lactic acid)/hydroxyapatite hybrid composite biomaterials

The present work reports on the incorporation of tungsten disulphide inorganic nanotubes (INT-WS2) into poly(L-lactic acid)/hydroxyapatite (PLLA/HA) and their effects on the processability, morphology, biocompatibility, thermal, tribological and mechanical properties of the resulting nanocomposites. Binary PLLA/HA and ternary PLLA/HA/INT-WS2 composites were successfully prepared using a conventional melt blending technique. Morphological analysis indicates that the incorporation of INT-WS2 into PLLA/HA improves the dispersibility of the HA microparticles and reduces their mean size, resulting in a larger interfacial area. Additionally, INT-WS2 can act as efficient nucleating agents as well as reinforcing fillers in PLLA/HA blends, thus remarkably enhancing their chemical and thermal stability, mechanical performance under dry and SBF conditions as well as tribological properties. The improvements are more pronounced in the hybrid nanocomposite with the highest HA content, likely due to a synergistic effect of both micro and nano-fillers on the matrix performance. Considering the good biocompatibility of the developed materials, the inexpensive synthetic process and the extraordinary properties of environmentally friendly INT-WS2, this work may open up opportunities to produce new biopolymer/hydroxyapatite hybrid nanocomposites that are of great interest in bone tissue engineering applications.