Photoresponsive Diarylethene-Based Polyolefins

Abstract Stimuli-responsive polymers are a class of functional materials that can undergo reversible physical or chemical changes in their structure, properties, or functions in response to external stimuli. In this work, we proposed a novel photoresponsive closed-loop polymer design strategy that integrates responsive molecular properties with the closed-loop concept, aiming to effectively address the long-standing challenges associated with the poor responsiveness and inadequate recyclability of traditional polymer materials. By combining the efficiency of ring-opening metathesis polymerization (ROMP) with the intrinsic thermal stability of photoresponsive molecular switches, we reported the (co)polymerization of photoresponsive diarylethene-based (DTE) cyclic monomers. This approach enables the rational design and preparation of photoresponsive polyolefins with tunable structures and properties, including mechanical performance, thermodynamic characteristics, and reversible color variation. We further explored equilibrium-controlled transformations to establish reversible closed-loop pathways for monomer–polymer interconversion. Notably, for the DTE-based homopolymer, a dual closed-loop platform was established via photoinduced transformation and Ru-catalyzed metathesis (de)polymerization. This work provides an efficient platform to advance the sustainable development and practical application of advanced responsive polymers.