Synthesis and Self-Organization of Poly(propylene oxide)-Based Amphiphilic and Triphilic Block Copolymers

Abstract

A series of amphiphilic diblock copolymers and triphilic triblock copolymer analogues of the architectures BA, CAB, and CBA have been synthesized and characterized with respect to their aggregation behavior in water. The A, B, and C components of the block copolymers are formed by hydrophilic poly(glycerol monomethacrylate) (PGMA), lipophilic poly(propylene oxide) (PPO), and a fluorophilic perfluoroalkyl segment, respectively. Their critical micelle concentrations in water are determined from surface tension measurements. The aggregation behavior of the copolymers, as investigated by DLS, SANS, AFM, and TEM, is found to be governed by the strong immiscibility between the lipophilic PPO blocks and the fluorophilic perfluorocarbon segments as well as the blocks sequence. It is found that the BA and CBA copolymers form clear micellar solutions in contrast to the CAB copolymer solutions which exhibit phase-separation above the LCST of the PPO block.