Nancy R. Sottos, University of Illinois at Urbana-Champaign
Thermoset polymers and composites exhibit excellent specific stiffness and strength, thermal stability, and chemical resistance. The manufacturing of high-performance thermosets and composites typically requires lengthy cure times at elevated temperatures, which presents significant challenges for additive manufacturing due to the required speeds of printing in comparison to the time required for the curing reaction, relaxation of the printed ink, interfacial bonding of the printed layers, and integration of high aspect ratio fibers, among many other factors. This talk will describe a new manufacturing platform for additive manufacturing of multifunctional thermoset polymers that combines frontal polymerization with extrusion-based direct ink writing to simultaneously print and cure neat polymer parts with minimal energy input. Exothermic release of energy during curing provides a positive feedback to drive further reaction, creating self-propagating curing front that self-regulates with the printing speed. Our approach to understand and exploit this process for rapid manufacture of complex shapes and structures is highly interdisciplinary and encompasses tuning of the monomer chemistry and rheology informed by in situ characterization and computational modeling of the mechanics of the printing process. We demonstrate several unique manufacturing capabilities that are not possible with traditional additive approaches.
Nancy Sottos holds the Maybelle Leland Swanlund Endowed Chair and is Head of the Department of Materials Science and Engineering at the University of Illinois Urbana Champaign. She is leader of the Autonomous Materials Systems (AMS) group at the Beckman Institute for Advanced Science and Technology and director of the University of Illinois spoke of the BP International Center for Advanced Materials. Inspired by autonomous function in biological systems, the Sottos group develops polymers and composites capable of self-healing and regeneration, self-reporting, and self-protection to improve reliability and extend material lifetime. Her current research interests focus on new bioinspired methods to manufacture these complex materials. Sottos is a member of the National Academy of Engineering (NAE), a Fellow of the American Association for the Advancement of Science (AAAS), Society for Experimental Mechanics (SEM) and the Society for Engineering Science (SES).