Fenton‐RAFT Polymerization: An “On‐Demand” Chain‐Growth Method

Fine control over the architecture and/or microstructure of synthetic polymers is fast becoming a reality owing to the development of efficient and versatile polymerization techniques and conjugation reactions. However, the transition of these syntheses to automated, programmable, and high‐throughput operating systems is a challenging step needed to translate the vast potential of precision polymers into machine‐programmable polymers for biological and functional applications. Chain‐growth polymerizations are particularly appealing for their ability to form structurally and chemically well‐defined macromolecules through living/controlled polymerization techniques. Even using the latest polymerization technologies, the macromolecular engineering of complex functional materials often requires multi‐step syntheses and purification of intermediates, and results in sub‐optimal yields. To develop a proof‐of‐concept of a framework polymerization technique that is readily amenable to automation requires several key characteristics. In this study, a new approach is described that is believed to meet these requirements, thus opening avenues toward automated polymer synthesis. Polymers on demand: A facile technique for the synthesis of controlled polymers is realized by using the Fenton reaction. The ability to degas the reaction mixture by using the same catalyst system and then grow the polymer chain through sequential H2O2 addition is highly promising for the development of an automated/programmable polymerization system utilizing sequenced reagent injection. The benign reaction conditions (room temperature, aqueous solvent) are non‐demanding, and the system is demonstrated to be compatible with a range of functional monomers.