Polyurethane/polyethersulphone composite hollow fibers produced by simultaneous spinning of two polymer solutions

In this work, composite hollow fibers were prepared by simultaneous spinning of two polymer solutions using a triple orifice spinneret. The polymer solutions were composed of a rubbery (polyurethane) and a glassy (polyethersulfone) polymer to form skin and support, respectively. Hollow fibers with those features are eligible to be used in many applications, including VOC recovery, and as facilitated transport membranes, given that carriers can be incorporated in the rubbery layer. Different synthesis conditions were investigated and the hollow fiber morphologies were characterized by scanning electron microscopy. The results showed that it is possible to produce the polyurethane/polyethersulphone composite membranes, with adhesion between the top and the support layers, and with dense skin. The use of a volatile solvent in the polyurethane solution, such as THF, different from the solvent in the support solution, also allowed the formation of hollow fiber membranes with dense skin and complete adhesion between the polyurethane and the polyethersulphone layers.