Polymer Backbone Editing with Cyclopropenes via Olefin Metathesis

The limited ability to recycle or upcycle many commodity polymers with all carbon backbones poses a significant challenge to polymer chemists and society as a whole. In this work, sterically hindered cyclopropenes (CPEs) are used to promote ring-opening cross metathesis reactions with alkene-containing polymers to upgrade the original materials into functional copolymers through a formal backbone editing process. This polymer backbone editing process was able to achieve high conversion of the CPEs (>90%) and maintain reasonable postediting molecular weights (>22 kDa). The method was applied to different CPEs and olefin-containing polymers, resulting in changes in the chemical and thermal properties of the resulting copolymer materials. This work advances avenues for polymer upcycling processes, offering new directions for repurposing widely used olefinic polymers.