Controlled Polymerization of Multivinyl Monomers: Formation of Cyclized/Knotted Single‐Chain Polymer Architectures

Seventy years ago, Flory and Stockmayer predicted that the polymerization of multivinyl monomers (MVMs) would inevitably lead to insoluble cross‐linked gel networks. Since then, the use of MVMs has largely been limited to as cross‐linking agents. More recently, however, polymerization strategies such as reversible deactivation radical polymerization (RDRP) have paved the way for the exploration of new possibilities in terms of both polymer architectures and functional capabilities. This Minireview provides historical context to the problem of polymerizing MVMs, before highlighting how RDRP has led to the formation of new cyclized/knotted polymer structures. Although the potential of such cyclized/knot polymer architectures is far from being fulfilled, some emerging applications are discussed. Tying up the growing chains: Chain propagation during the polymerization of multivinyl monomers (MVMs) can occur through three pathways: monomer addition as well as intermolecular and intramolecular cross‐linking. Increasing the degree of intramolecular cyclization in a highly controlled way leads to the formation of in‐chain loops, and ultimately a cyclized/knotted single‐chain polymer architecture can be synthesized.