A Biomimetic Strategy for On-Demand, Solvent-Free Deconstruction of Cross-Linked Polyurethane Networks

Cross-linked polymer networks face an inherent trade-off: the same covalent architecture that ensures mechanical integrity also creates mass-transport barriers that hinder chemical deconstruction. As a result, robust functional materials—soft electronics, lightweight composites—are notoriously difficult to recycle without harsh solvents, laborious sorting, or loss of their valuable components. In this talk, we present a molecularly engineered polyurethane network designed to resolve this conflict. Drawing on how biological systems localize catalytic activity to specific targets, we embed a flexible crosslinker that pre-organizes the network for rapid disassembly. This design substantially lowers the kinetic barrier to deconstruction compared with physically blended or externally catalyzed analogues, enabling on-demand depolymerization without added solvent or catalyst. Under a simple thermal-vacuum trigger, the network undergoes a direct solid-to-vapor transition, allowing selective monomer recovery together with reclamation of embedded functional fillers such as liquid-metal conductors and carbon fibers. The process tolerates unsorted mixed-plastic waste and multicomponent composites, and the recovered building blocks can be reprocessed into materials of comparable performance to the pristine system. We will discuss the design principles behind this dual-role network and their broader implications for the circular design of high-performance functional materials. As this work is not yet published, quantitative details will be presented at the meeting.