Novel RAFT Agent Synthesis for the Preparation of Polystyrene Diol Oligomers for Polyurethane Synthesis

The features of versatile and widely used polyurethanes (PU) are largely determined by the intrinsic properties of the used oligomer polyols. Commonly used polyols are polyether (PEP), polyester (PES), and polycarbonate (PC) diols. In addition to these, vinyl‐based compounds like oligomeric styrenes or acrylics provide benefits in terms of property improvement. The synthesis of such polyols yielding so‐called hybrid systems relies on chain growth reactions that represent severe challenges regarding the implementation of well‐defined OH‐(end)functionality. Controlled radical polymerization techniques like reversible‐addition‐fragmentation chain‐transfer polymerization (RAFT) are known to be capable of implementing well‐defined termini. Here, we report on an effective synthesis route to a RAFT agent for the production of well‐defined OH‐terminated styrene oligomer diols, in order to expand the toolbox of building blocks for PU synthesis.