Zwitterionic Copolymerization: Synthesis of Cyclic Gradient Copolymers

Abstract

How to get rich fast: The zwitterionic copolymerization of δ-valerolactone (VL) and ε-caprolactone (CL) provides an expedient route to cyclic gradient copolymers. The faster ring-opening of VL relative to CL with N-heterocyclic carbenes, coupled with sufficiently long lifetimes of the growing zwitterions leads to a polymer structure comprised of VL-rich sequences that transition to CL-rich sequences in a cyclic macromolecule (see scheme). Detailed facts of importance to specialist readers are published as ”Supporting Information”. Such documents are peer-reviewed, but not copy-edited or typeset. They are made available as submitted by the authors. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.