Multi-arm polymers, which consist of multiple linear chains connected to a central core, have a unique set of properties (e.g. crystalline, mechanical, and viscoelastic properties,) when compared with their linear analogs due to their multi-arm structure, globular shape and multiplicity of end groups. However, the synthesis of multi-arms polymer with a tailored number of arms and control over the length of the each arm can be challenging. In this work, high purity homo-arm and mikto-arm poly(ethylene glycol) (PEG) stars were successfully prepared by the combination of epoxide ring openings and azide-alkyne click reactions. First, monohydroxy-PEG was modified via epoxide chemistry to bear one hydroxyl and one azide functionality at the same end. An alkyne functionalized PEG chain was then coupled to the azide. Subsequently, the remaining hydroxyl could be reactivated to an azide again and again to enable stepwise addition of alkyne functionalized polymer arms. The use of efficient reactions for this iterative route provided star polymers with an exact number of arms, and a tailorable degree of polymerization for each arm. Detailed characterization confirmed the high purity of multi-arm poly(ethylene glycol) products

Efficient synthesis of high purity homo-arm and mikto-arm poly(ethylene glycol) stars using epoxide and azide-alkyne coupling chemistry

247th National Meeting (2014)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.