Synthesis of ABC 3-Miktoarm Star Terpolymers from a Trifunctional Initiator by Combining Ring-Opening Polymerization, Atom Transfer Radical Polymerization, and Nitroxide-Mediated Radical Polymerization

Abstract

We report a new method to synthesize ABC 3-miktoarm star terpolymers by combining three different controlled/“living” polymerization techniques: ring-opening polymerization (ROP), atom transfer radical polymerization (ATRP), and nitroxide-mediated radical polymerization (NMRP). A trifunctional initiator bearing a hydroxy group, an ATRP initiator, and a NMRP initiator was designed and synthesized. The structure was confirmed by 1H NMR, 13C NMR, and mass spectroscopy. ABC star terpolymers were then prepared from the trifunctional initiator by sequential ROP of e-caprolactone, ATRP of methyl methacrylate, and NMRP of styrene. GPC and kinetic analysis indicated that the polymerizations were controlled. The 3-miktoarm star structure was further confirmed by cleavage of a star terpolymer.