Telechelic Dithiol Copolymers as Tunable Building Blocks for Synthesizing Multiblock Materials

A new strategy is reported to access α,ω-dithiol polymer building blocks with tunable molecular weights and compositions for the preparation of random multiblock copolymers based on styrenic, acrylic, and siloxane repeat units. This facile synthetic approach provides access to dithiols through a two-step process: (1) an initial copolymerization of vinyl monomers with ethyl lipoate followed by (2) disulfide bond reduction, producing dithiol terminated polymer products. Thiol-terminated polymers are easily prepared over a wide range of molecular weights (2–32 kDa) by simply controlling the feed ratio of vinyl monomer to ethyl lipoate. Mixtures of these linear dithiol-terminated building blocks were repolymerized via oxidative coupling to create random multiblock copolymers with high molecular weights (68–95 kDa) and controlled degradability. In summary, this approach for preparing and recombining telechelic dithiol polymers creates opportunities to manipulate the mechanical and physical properties of multiblock copolymers using a synthetically simple and versatile platform.