Macrocyclic Allylic Sulfone as a Universal Comonomer in Organocatalyzed Photocontrolled Radical Copolymerization with Vinyl Monomers

Radical copolymerization of vinyl monomers and cyclic monomers is a versatile approach to degradable vinyl plastics. Despite recent advances, a class of “universal” cyclic monomers that possess broad reactivities with various types of vinyl monomers remains elusive. Herein, we report a general method for the organocatalyzed photocontrolled radical ring-opening cascade copolymerization (rROCCP) of macrocyclic allylic sulfone and various types of vinyl monomers, including acrylates, acrylamides, styrene, and methacrylate. Catalyzed by Eosin Y under visible light irradiation, the copolymerization of macrocyclic allylic sulfone and acrylic monomers displayed near unity comonomer reactivity ratios by fitting the copolymer composition to the Beckingham–Sanoya–Lynd integrated model. Macrocyclic allylic sulfone was also successfully copolymerized with styrene (r₁ = 3.02 and r_St = 0.35) or methyl methacrylate (r₁ = 0.18 and r_MMA = 5.81) to generate degradable polystyrene and poly­(methyl methacrylate). These degradable vinyl copolymers exhibited tunable thermal properties correlated with the incorporation of the degradable main-chain diester motif. The unprecedented reactivities that macrocyclic allylic sulfone demonstrated in the organocatalyzed photocontrolled rROCCP provide a general approach to the wide range of degradable vinyl plastics with various structures and functions.