A series of well-defined ABC 3-Miktoarm star-shaped terpolymers [Poly(styrene)-Poly(ethylene oxide)-Poly(e-caprolactone)](PS-PEO-PCL) with different molecular weight was synthesized by combination of the ‘‘living’’ anionic polymerization with the ring-opening polymerization (ROP) using macro-initiator strategy. Firstly, the ‘‘living’’ poly(styryl)lithium (PSLiþ) species were capped by 1-ethoxyethyl glycidyl ether(EEGE) quantitatively and the PS-EEGE with an active and an ethoxyethyl-protected hydroxyl group at the same end was obtained. Then, using PS-EEGE and diphenylmethylpotassium (DPMK) as coinitiator, the diblock copolymers of (PS-b-PEO)p with the ethoxyethyl-protected hydroxyl group at the junction point were achieved by the ROP of EO and the subsequent termination with bromoethane. The diblock copolymers of (PS-b-PEO)d with the active hydroxyl group at the junction point were recovered via the cleavage of ethoxyethyl group on (PS-b-PEO)p by acidolysis and saponification successively. Finally, the copolymers (PS-b-PEO)d served as the macroinitiator for ROP of e-CL in the presence of tin(II)-bis(2-ethylhexanoate)(Sn(Oct)2) and the star(PS-PEO-PCL) terpolymers were obtained. The target terpolymers and the
intermediates were well characterized by 1H-NMR, MALDI-TOF MS, FTIR, and SEC.