The depolymerization of polybutadiene by Ru carbenes is a highly efficient catalytic reaction that involves chain scission by ring-closing metathesis (RCM) of fortuitously placed double bonds on the polymer chain. Inspired by this motif, we designed several unsaturated diols that favor intramolecular RCM to stable cycloalkenes. These diols were polymerized with a range of multi-functional isocyanates to prepare novel linear and crosslinked polyurethanes (PUs). The unsaturated portion of the resulting PU chains undergoes analogous RCM as in the starting diols. Based on careful design of the double bond configuration, a critical consequence of RCM is cleavage of the polymer chain, leading to net depolymerization. We show that the crosslinked PUs can be readily degraded, often to soluble products, when soaked in dilute solutions of Ru carbenes. Our approach to rendering polymers depolymerizable is potentially applicable to other condensation polymers in addition to PUs, and thus may ultimately allow for better disposal or recovery and reuse of a variety of otherwise permanent polymers.

Polyurethanes rendered depolymerizable by introduction of a metathesis cleavable co-monomer

Macromolecular Chemistry: The Second Century

[Author Benefits](https://scimeetings.acs.org/?utm_source=pubs_content_marketing&utm_medium=website&utm_campaign=0320_MCF_NPI_Launch_Spring_Homepage&ref=pubs_content_marketing)

[How to use SciMeetings](https://storage.googleapis.com/dl.morressier.com/acs/SciMeetings-ACSSpring2020-HowToGuide_M3020-Final.pdf)

[Frequently Asked Questions](https://storage.googleapis.com/dl.morressier.com/acs/SciMtng_ACSNMSp2020_FAQ_M3120_Final.pdf)

ACS Spring 2020 National Meeting & Expo

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.