A novel, near-monodisperse, well-defined ABA triblock copolymer, poly[2-(dimethylamino)ethyl methacrylate]-b-poly(propylene oxide)-b-poly[2-(dimethylamino)ethyl methacrylate], was synthesized via oxyanion-initiated polymerization. The initiator was a telechelic-type potassium alcoholate prepared from poly(propylene glycol) and KH in dry tetrahydrofuran. The copolymers produced were characterized by Fourier transform infrared, H-1 NMR, and gel permeation chromatography (GPC). GPC and H-1 NMR analyses showed that the products obtained were the desired copolymers, with narrow molecular weight distributions (ca. 1.09-1.11) very close to that of the original poly(propylene glycol). H-1 NMR, surface tension measurements, and dynamic light scattering all indicated that the triblock copolymer led to interesting aqueous solution behaviors, including temperature-induced micellization and very high surface activity.