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

Reductively degradable polymers can be utilized as environmentally friendly polymers because of their degradability in the ocean, and it is important to develop synthetic methods for reduction-degradable polymers. From the viewpoint of applications, it is desirable that the structure and functional groups of the polymer side chains be freely controlled to regulate the physical properties of the degradable polymer. In this study, a new domino polymerization approach is developed for the synthesis of reductively degradable poly(disulfide)s with arbitrary side chains. In this polymerization method, poly(disulfide)s can be synthesized by mixing a newly designed monomer with thiolactone and pyridyl disulfide groups with various amines, in which the thiolactone ring-opening and disulfide-exchange reactions proceed continuously. In addition, the post-modification of poly(disulfide)s with hydroxyl and alkyne groups is achieved. The reductive degradability of the poly(disulfide)s synthesized using this method is confirmed using gel permeation chromatography and mass spectrometry. This polymerization technique will lead to the development of reductively degradable polymers with various functions for use in various applications in the future.