Degradable Vinyl-Based Polymers by Radical Ring-Opening Polymerization: A User Guide

Low weight, low price, and excellent long-term stability are the main advantages of vinyl-based polymers. Such polymers are obtained by chain-growth processes leading to all-carbon backbones, which are non-(bio)-degradable and nonchemically recyclable. Unfortunately, this chemical stability manifests as postuse persistence; coupled with poor waste management practices, polymers including vinyl derivatives pose major environmental problems today. Given that it is very difficult and costly to design entirely new materials that have both desired properties (mechanical, thermal, solvent resistance, etc.) and recyclability and/or biodegradability at the end of their life cycle, it seems worthwhile to transform already known materials into (bio)-degradable/chemically recyclable equivalents. One approach is based on the introduction of cleavable bonds into the polymer backbone, so that degradation (by hydrolysis, for example) produces oligomers which can then be further recycled and/or bioassimilated by micro-organisms. An effective method for incorporating weak bonds randomly into the C-C backbone of a vinyl polymer is the copolymerization of vinyl monomers with cyclic monomers by radical ring-opening polymerization (rROP). This method combines the advantages of ring-opening and radical polymerization, i.e., the production of polymers with heteroatoms and/or functional groups in the main chain, with the robustness, ease of use, and mild polymerization conditions of a radical process. The aim of this tutorial review is to provide polymer chemists with guidelines to use rROP to prepare vinyl-based materials with predictable degradation. This review thus presents the rROP principle, the main families of cyclic monomers copolymerizable with vinyl monomers, and the main applications of the resulting (bio)-degradable/chemically recyclable materials (polymers for packaging, latexes and degradable surfaces, 3D printing, biomaterials and water-soluble polymers).