Radical Polymerization of Methylene Heterocyclic Compounds: Functional Polymer Synthesis and Applications

Abstract Synthetic polymers sustain a wide range of applications but the quest for further sophistication and functionalization of polymers remains topical to improve their scope and performance. In this respect, the radical polymerization of exo-methylene heterocyclic compounds (MHCs) is attractive. Compared to the classical acyclic vinyl monomers constrained to the vinyl-type polymerization process, MHCs can undergo different polymerization modes, namely the radical ring-retaining polymerization (rRRP) and the radical ring-opening polymerization (rROP). In rRRP, the cyclic group is preserved and inserted as side group of the polymer backbone offering a myriad of post-polymerization modifications whereas functional groups are incorporated within the backbone of linear polymers and confer them some degradability in rROP. Herein, recent advances in the radical polymerization of MHCs as well as the variety of macromolecular structures and applications it offers are highlighted. The reversible deactivation radical polymerization of MHCs leading to well-defined MHC-based macromolecular architectures, including multifunctional, stimuli-responsive and degradable polymers, is also discussed. The review emphasizes the current limitations of the radical polymerization of MHCs as well as future prospects including the development of innovative bio-based MHCs. Overall, the radical polymerization of MCHs represents a powerful macromolecular engineering tool and a broad field of exploration for polymer chemists. Graphical Abstract