Summary: Coupling reactions between terminal functionalized polymer chains were chosen for the synthesis of star‐like polymers consisting of polystyrene and polystyrene‐block‐polystyrene‐co‐(butyl acrylate)] arms. For the preparation of terminal functionalized polymer chains a side reaction of the 2,2,6,6‐tetramethylpiperidine‐N‐oxyl (TEMPO) mediated free radical polymerization of methacrylates could be used successfully to convert TEMPO terminated polymers into end functionalized polymers. The number of functionalized monomer units attached to the polymer chain is directly related to the TEMPO concentration during this reaction. Different polystyrenes and polystyrene‐block‐polystyrene‐co‐(butyl acrylate)] block copolymers were functionalized with a variable number of epoxide and alcohol groups at the chain end. For the determination of the optimal reaction parameters for the coupling reactions between these polymer chains, epoxy functionalized polystyrenes were converted with hydroxy functionalized polystyrenes under basic and acidic conditions. By activation with sodium hydride or boron trifluoride star‐like polymers were synthesized under mild conditions. The transfer of the reaction conditions to coupling reactions between end functionalized polystyrene‐block‐polystyrene‐co‐(butyl acrylate)] copolymers showed that star‐like polymers with more than 12 arms were formed using boron trifluoride as activating agent.
