Oligomeric cationic surfactants prepared from surfmers via ATRP: Synthesis and surface activities

Abstract

A series of oligomeric cationic surfactants were prepared directly in aqueous media by atom transfer radical polymerization (ATRP) of methacrylate surfmers. The molecular weight of oligomeric surfactants was characterized by 1H NMR, and the results were close to those obtained via GPC analysis. The resulting oligomers have narrow molecular weight distributions, with polydispersity indices in the range of 1.18–1.32, and the research indicated that the synthesis of the oligomeric surfactants was consistent with characteristics of controlled free radical polymerization. The surface activities of oligomeric surfactant solutions were examined, and it was found that their surface activities were enhanced when increasing oligomerization degree or hydrophobic chain length, in agreement with what observed for oligomeric surfactants prepared by classic organic synthesis. Spherical vesicles formed by these oligomers prepared via ATRP were observed by Cryo-TEM. It was proved that ATRP possesses the advantages over classic organic synthesis, as it provided a simple and easy route for synthesizing oligomeric surfactants with well-controlled architecture.