Nanocomposites of PLA containing ZnO nanofibers made by solvent cast 3D printing: Production and characterization

PLA nanocomposites containing 1 wt% ZnO nanofibers have been prepared by solvent-cast 3D printing. The ZnO nanofibers were produced by electrospinning and dispersed in PLA by ultrasound. Scanning electron microscopy revealed that the fibers were dispersed throughout the nanocomposite. Surface specimen assessment by atomic force microscopy indicated the presence of nanofibers near the surface of the nanocomposite. TGA tests showed the nanocomposite had a lower thermal stability than the neat PLA, probably induced by PLA hydrolysis catalyzed by ZnO. DSC results revealed higher crystallinity in the nanocomposite, induced both by the presence of ZnO nanofibers and by the 3D printing process, though the 3D printing process showed to be more important in increasing the crystallinity. XRD results also showed a higher crystallinity for the nanocomposite. The study opens an interesting field for the development of PLA/ZnO nanocomposites using ZnO nanofibers made by electrospinning, e.g. in medical and packaging applications.