Microstructural Changes of Graphene/PLA/PBC Nanofibers by Electrospinning during Tensile Tests

This study focuses on the nanostructure and nanostructural changes of novel graphene/poly(lactic acid) (PLA)/ poly(butylene carbonate) (PBC) nanofibers via electrospinning, which are characterized by differential scanning calorimetry (DSC), scanning electron microscopy (SEM), tensile test and in situ small angle x-ray scattering. DSC indicates that the endothermic peak at 295^\circ\!C of pure PLA/PBC nanofibers shifted from 317^\circ\!C to lower 290^\circ\!C with the increasing graphene content. SEM observations reveal a fine dispersion of graphene in the nanofiber matrices. The graphene/PLA/PBC nanofibers exhibit good improvements in mechanical property. The tensile strength of nanofibers increases with the addition of 0.01 g graphene but reduces with further addition of 0.04 g graphene. The scattering intensities increase dramatically when the strain levels are higher than the yield point due to the nucleation and growth of nanovoids or crystals. However, the increasing content of graphene in the PLA/PBC matrix provokes a strong restriction to the deformation-induced crystals.