Effect of Polycaprolactone, Zinc Oxide, and Poly(ethylene glycol) on the Properties of Polylactic Acid Composite Fibers Obtained by Melt Electrospinning.

Polylactic acid (PLA) composite fibers were obtained using melt electrospinning, in which a high voltage was applied to the nozzle of the 3D printer. Filaments for melt electrospinning were prepared by using an extruder operated at 155 °C. PLA was mixed with polycaprolactone (PCL; 95:5, 90:10, and 85:15 by wt %), zinc oxide (ZnO; 0.1 phr), and poly(ethylene glycol) (PEG; 1 phr). The prepared filaments and fibers were characterized by Fourier-transform infrared spectroscopy (FTIR), contact angle measurements, thermal gravimetry (TGA), differential scanning calorimetry (DSC), and dynamic mechanical analysis (DMA). The measured contact angles of the filaments were in the range of 60.33° (±4.04) to 78° (±2.65), while the melt-electrospun fibers were in the range of 110.17° (±0.29) to 128.5° (±1.32). Melt electrospinning significantly increased the contact angle. According to the DSC analysis, the addition of 0.1% ZnO and 1% PEG increased the degree of crystallinity of PLA from 19.63 to 27.48% in the filaments and 11.54 to 20.79% in the fibers. The Avrami constant () values of the filaments and fibers were found in the range between 2.62-3.97 and 2.75-3.95, respectively. It was shown that the crystallization was controlled by nucleation. DMA analysis indicated that melt electrospinning and the addition of PCL decreased the storage modulus of the filaments, thereby increasing their plasticity.