Abstract
Blend fibers consisting of equal amount of poly(L-lactic acid)(PLLA)and poly(D-lactic acid)(PDLA)were prepared by a melt-electrospinning process using a CO2 laser irradiation. The fiber structure was investigated by a differential scanning calorimetry, a scanning and a transmission electron microscopies, and an X-ray diffraction. The average fiber diameter decreased and the width of the diameter distribution tended to be narrower with increasing applied laser output power. The melting endotherm of the stereocomplex crystal(Sc)around 220 °C became larger and sharper while that of the homo-chiral crystal(Hc)around 170 °C became smaller with increasing laser output power. The X-ray diffraction patterns of the annealed fibers indicated the coexistence of an oriented Hc and a randomly oriented Sc. However the selected-area electron diffraction pattern revealed that Sc in the annealed very fine fiber has higher degree of orientations of Hc and Sc to the fiber direction than those in the fiber with larger diameter.
