Functional cyclic disulfides enable multi-pathway degradable polyvinyls.

Copolymerization of vinyl monomers with functional seven-membered cyclic disulfides enables the synthesis of polyvinyl esters capable of undergoing distinct degradation pathways. More generally, the incorporation of cleavable linkages into polyvinyl backbones via radical copolymerization provides a powerful strategy toward degradable materials while preserving the versatility and scalability of vinyl polymerization. Here, we introduce molecularly designed seven-membered cyclic disulfides as comonomers for radical copolymerization with vinyl esters, enabling incorporation of both disulfide and ester functionalities along polyvinyl backbones. In particular, the ester-functionalized monomer 1,4,5-oxadithiepan-2-one (ODP) affords copolymers that undergo reductive disulfide cleavage, glutathione (GSH)-mediated thiol-disulfide exchange, and hydrolytic backbone fragmentation under mildly basic conditions. The copolymerization behavior of seven-membered cyclic disulfides with vinyl esters provides insight into structure-reactivity relationships in radical ring-opening copolymerization, while remaining compatible with photoiniferter RAFT/MADIX polymerization. Water-soluble copolymers derived from diethylene glycol vinyl esters form highly hydrated, protein-repellent films, combining bioinert interfacial properties with susceptibility to degradation through orthogonal chemical pathways. These results establish functional seven-membered cyclic disulfides as a versatile platform for the synthesis of degradable and potentially biodegradable polyvinyl materials.