Synthesis of Star-shaped Miktoarm Terpolymers Composed of Polyisoprene, Polystyrene, and Poly (2,2,2-trifluoroethyl methacrylate) via Arm-first Approach

Star-shaped ABC miktoarm terpolymers consisting of three different polymers are wellknown to form a much richer variety of microphase-separated structures than linear AB-type diblock copolymers due to the addition of a third block. ABC-type block copolymers show promise in various applications, including multifunctional sensors, catalysts, separation membranes, and filters. Star-shaped miktoarm terpolymers have attracted significant attention because of their unique chemical structures, morphologies, and novel physical attributes that were never thought possible for linear polymers. However, star-shaped miktoarm terpolymers are synthetically challenging because combining different polymerization methods and multiple protection strategies are usually necessary to synthesize these polymers. Our research group, therefore, tried to synthesize star-shaped ABC miktoarm terpolymers in a one-pot two-step fashion by combining multicomponent reaction (MCR) and click reaction. To achieve this method, we considered the synthetic strategy of combining three different polymer arms. In this 'arm-first' approach, the star-shape miktoarm terpolymers composed of (PI)(PS)(PTFEMA) (PI: polyisoprene, PS: polystyrene, PTFEMA: poly(2,2,2-trifluoroethyl methacrylate)) are synthesized through an MCR involving CO2, 2 , PI with an alkyne terminus, and PS with a bromo terminus, followed by a post-modification step where PTFEMA with an amino terminus is attached via an amino-yen click reaction.