The morphology, mechanical properties, and flammability of aligned electrospun polycarbonate (PC) nanofibers

Abstract

AbstractThe electrospinning of the polycarbonate (PC) solutions was performed for the variable electrospinning parameters such as polymer concentration, solvent composition, applied voltage, flow rate, and take‐up velocity in order to evaluate changes of morphology, mechanical properties, and flammability of the aligned PC nanofibers as a function of the electrospinning parameters. It was found that the ratio of THF/DMF solvent in the electrospinning parameters had a major effect on the spinnability and fiber morphology. Furthermore, it was confirmed that the mechanical properties were dependent upon the fiber morphology. The spinnability of the PC solutions with a lower THF ratio in THF/DMF solvent was poor. The aligned electrospun PC fiber with the best morphology was made in the range of polymer concentration of 22%, solvent ratio of 50:50 THF : DMF, applied voltage of 14 kV, flow rate of 0.050 ml/m, and a take‐up velocity of 7.3 m/s. The ultimate strength and initial modulus of the 80% drawn 22% PC fiber were 64 ± 2 MPa (commercial 55–75 MPa) and 1.9 ± 0.1 GPa. The heat release capacity (HRC) of the 22 and 25% PC fiber were 275 ± 27 J/g K and 198 ± 1 J/g K. It was found that the flame resistance of the electrospun PC nanofiber was superior to that of the PC raw material (HRC ∼360 J/g K). POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers