Production and comparison of solution and melt electrospun thermoplastic polyurethane nanofibers

In this work, nanofiber production technology by means of electrospinning method was studied. Solution electrospinning and melt electrospinning setups were established in order to produce nanofibers from thermoplastic polyurethane (TPU). Because of their high flexibility and soft touch, TPU nanofibers provide several advantages in different industries especially in textile. In the experimental studies, three different solutions of TPU with dimethylformamide were prepared and transferred into a feeding unit which enables to adjust and regulate solution flow in the solution electrospinning process. In addition to solution concentration, applied voltage, processing time and distance between collector and feeding unit were used as the main experimental parameters. In melt electrospinning process, a commercial melt flow index test equipment was used as the feeding unit. Since the electrospinning process was not able to take place with the original spinneret of the melt flow index device, a new spinneret was designed. Having integrated the newly designed spinneret and protector cabin onto the system, the melt electrospinning process was then possible. Polymer processing temperature, applied voltage, processing time and distance between collector and feeding unit were variables of melt electrospinning process. In conclusion, a specially designed apparatus for processing TPU were used to compare the processes of melt and solution electrospinning. In addition to process observations, electrospun fiber collections and morphologies were examined by characterizing the electrospun fibers qualitatively and quantitatively using scanning electron microscope (SEM) images (Figure 1) (Figure presented.). When the results obtained from this study are compared with former studies, some improvements achieved in the final product such as very low standard deviation values in solution electrospun nanofibers. On the other hand, melt electrospinning of TPU polymer had not been investigated before this study. So, this study would be a guide for further studies in this field.