Degradable Vinyl Random Copolymers via Photocontrolled Radical Ring‐Opening Cascade Copolymerization**

Abstract

Degradable vinyl polymers by radical ring‐opening polymerization are promising solutions to the challenges caused by non‐degradable vinyl plastics. However, achieving even distributions of labile functional groups in the backbone of degradable vinyl polymers remains challenging. Herein, we report a photocatalytic approach to degradable vinyl random copolymers via radical ring‐opening cascade copolymerization (rROCCP). The rROCCP of macrocyclic allylic sulfones and acrylates or acrylamides mediated by visible light at ambient temperature achieved near‐unity comonomer reactivity ratios over the entire range of the feed compositions. Experimental and computational evidence revealed an unusual reversible inhibition of chain propagation by in situ generated sulfur dioxide (SO2), which was successfully overcome by reducing the solubility of SO2. This study provides a powerful approach to degradable vinyl random copolymers with comparable material properties to non‐degradable vinyl polymers.

Cleavable Comonomers for Chemically Recyclable Polystyrene: A General Approach to Vinyl Polymer Circularity

“…Additionally, Guillaneuf and co-workers recently reported on analogous copolymers between DOT and styrene . Nevertheless, despite significant progress for rROP with various copolymer compositions − and attempts at repolymerization of oligomeric fragments obtained by other means, − to our knowledge, circularity (i.e., production of recycled materials of comparable properties) via the comonomer approach has not been demonstrated for PS or any other vinyl polymer, regardless of the comonomer reactivity ratios.…”

Recent advances in the ring-opening polymerization of sulfur-containing monomers

“…To overcome reactivity complications, the same group recently reported a photoinduced electron transfer-reversible addition fragmentation chain transfer (PET-RAFT) approach. 113 For instance, the homopolymerization of M78 mediated by an iridium complex under 450 nm irradiation yielded polyM78 with an M n of 9.8 kg mol −1 ( Đ = 1.11), thereby showing excellent control over the polymerization. A diblock copolymer polyM75- b -M78 ( M n = 13.0 kg mol −1 , Đ = 1.20) was also synthesized under similar conditions.…”

RAFT-Mediated 3D Printing of “Living” Materials with Tailored Hierarchical Porosity

“…The “living” character of the 3D materials is offered by the incorporated RAFT functionalities within the constituting structure of 3D materials that are capable of reversibly deactivating the propagating polymer chains. , The dormant RAFT species can be reactivated (thermally or under light exposure) in a post-printing stage to allow spatiotemporal insertion of new monomers/polymers into the strands of existing 3D polymers, surface functionalization, ,, welding/self-healing, , and/or expansion of an already fabricated material. − From the viewpoint of sustainability and recyclability, materials that can undergo controlled changes in a post-printing stage can address the challenges associated with 3D-printed waste polymers and pave the way for future advancements and scaling-up of the 3D technology. Taking a step back, RAFT is a family of reversible deactivation radical polymerization reactions that has become progressively popular as it can offer controlled synthesis of well-defined polymer chains with high chemical fidelity, − micro- and nanoparticles of different architectures, surface functionalization, sequence-defined polymers, etc …”

“…Taking a step back, RAFT is a family of reversible deactivation radical polymerization reactions that has become progressively popular as it can offer controlled synthesis of well-defined polymer chains with high chemical fidelity, 38−46 micro-and nanoparticles of different architectures, 47 surface functionalization, 48 sequence-defined polymers, 49 etc. 50 The development of RAFT-mediated 3D printing was inspired by studies on reprocessable polymer networks based on dynamic covalent bonds, 51,52 structurally tailored and engineered macromolecular (STEM) gels, 53,54 and trithiocarbonate (TTC)-containing systems. 35,37 .…”