Syndiotactic polypropylene nanofibers obtained from solution electrospinning process at ambient temperature

Fabrication of semicrystalline syndiotactic polypropylene (sPP) nanofibers by solution electrospinning was studied. It was found that sPP nanofibers with an average diameter of 230 nm were successfully fabricated via solution electrospinning with methylcyclohexane as solvent at room temperature (25°C). The obtained diameter was significantly thinner than the minimum diameter of 350 nm of PP fibers that were reported previously. It was also found that increasing viscosity of the sPP solution, which was customarily a useful way of fabricating noncrystalline thin fibers, was found ineffectual in producing thinner semicrystalline sPP fibers in our experiments. In fact, a careful selection of solvent by considering the evaporation rate and the specific viscosity could effectively lead to the fabrication of thinner sPP fibers by imposing proper elongation and preventing the sPP solution from gelation. The results could be applied to other semicrystalline polyolefins with similar gelation characteristics analogous to sPP to produce thinner nanofibers.