Domino Polymerization for the Synthesis of Reductively Degradable Poly(disulfide)s With Arbitrary Side-Chain...

The environmental persistence of conventional plastics has driven the development of degradable polymers with functional versatility. Poly(disulfide)s are particularly attractive due to their reductive degradability and environmentally triggered disassembly. In this study, we report a domino polymerization strategy that enables the rapid and modular synthesis of functional poly(disulfide)s with degradable main chains and diverse side-chain structures. This method utilizes a single monomer, N-(2-oxotetrahydrothiophen-3-yl)-3-(pyridin-2-yldisulfanyl)propanamide (PDTL), which contains both thiolactone (TL) and pyridyl disulfide (PDS) moieties. Polymerization is initiated by TL ring-opening with commercially available amines, generating thiol groups that undergo disulfide exchange with PDS moieties of other monomers, resulting in chain propagation. The method accommodates primary, secondary amines, and ammonia, allowing incorporation of alkyl, allyl, propargyl, hydroxyl, carboxyl, amide, and tertiary amine functionalities. The reductive degradability of the poly(disulfide)s is confirmed using gel permeation chromatography and mass spectrometry. Furthermore, it is found that pH-responsive properties appear in poly(disulfide)s possessing dimethylamino groups, where water solubility can be regulated in response to pH. Domino polymerization is further applied to synthesize reductively degradable poly(disulfide) gels using multi-functional amines. This polymerization technique will lead to the development of reductively degradable polymers with various functions for use in various applications in the future.