(649b) Crosslinked Fiber Production Via Simultaneous Centrifugal Spinning and Thiol-Ene Photopolymerization

Authors: 
Fang, Y., The University of Texas at Austin
Ellison, C. J., The University of Texas at Austin

Current synthetic fiber manufacturing technologies typically use either solvent or heat to transform a solid preformed polymer into a liquid before applying a force to draw the liquid into fiber. While the use of solvent poses concerns regarding process safety, environmental impact, and solvent recovery, the use of heat may lead to polymer degradation and excessive energy consumption. To address these critical problems, here we present an alternative fiber manufacturing method that encompasses extruding a monomer solution using centrifugal forcespinning while simultaneously polymerizing the monomers into solid fiber using UV initiated thiol-ene chemistry. This method not only negates the use of both heat and solvent, but also produces fibers that are highly crosslinked, mechanically robust, and thermally stable. In this process, the balance between curing kinetics, fiber flight time, and solution viscoelasticity is essential for fiber formation. An operating diagram is developed to show how the intricate interplay of these key factors lead to the formation of smooth fibers and other undesirable fiber defects such as beads-on-string, fused fibers, non-uniform fibers, and spray. In addition, the influence of processing parameters such as solution viscosity, spin speed, and orifice diameter on fiber diameter will be addressed.