| Abstract: | A series of cyclic poly[(styrene)‐b‐(ethylene oxide)] diblock copolymers 4 (1.5 kg/mol < Mn < 1.1 kg/mol) with narrow molecular weight distributions (I ≤ 1.12) have been synthesized. They were obtained by intramolecular cyclization of linear α‐diethyl acetal‐ω‐styrenyl poly(styrene ethylene oxide) 3 , under high dilution conditions. The use of well‐defined linear precursors in association with a cyclization process based on an unimolecular end‐to‐end coupling reaction allows the formation of macrocyclic diblocks in high yield (more than 90%). The structural characterization and the solution behavior of both the linear and cyclic amphipathic diblock copolymers have been investigated by means of NMR, size exclusion chromatography, and viscosimetry. |
