Polyurethane Nanofiber Polymer: preparation, production, characterization and properties

The present article provides an overview of polyurethane (PU) nanofibers (NFs), focusing on the process of fabrication of electrospun PU-NFs using the electrospinning method. The electrospinning device is used to produce PU by changing three main parameters in order to control the shape and thickness of the fibers, as well as the presence of bubble-like structures in the produced fibers. The first parameter is the PU concentration (8% and 10%), but this requires knowledge of the concentrations of the solvent (DMF: dimethylformamide, and THF: tetrahydrofuran). The second parameter is the flow rate of the dissolved PU from the syringe needle (0.02 and 0.03 mL/min), and the third parameter is the distance between the needle tip and the metal plate of the electrospinning device (7, 10, and 15 cm). These parameters were calibrated to obtain a sample with the desired strength and pressure characteristics. The obtained PU fibers are characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). The results show that 10% of PU fibers are in the nanoscale range in diameter and present a typical FTIR PU profile. Two concentrations were studied (8% and 10%), but only 10% systems gave satisfactory results. Because of their excellent mechanical properties, electrospun PU-NFs can be used in a wide range of applications, including high-performance air filters, wound dressing materials, protective textiles, and much more.