Facile synthesis of multiarmed and multicomponent star polymers by a new iterative methodology using (formyl-protected 1,3-dioxolane)-end-functionalized polymer anions

Abstract

A new and efficient iterative methodology using (formyl-protected 1,3-dioxolane (DOL))-end-functionalized polymer anions was carried out for the facile synthesis of multiarmed and multicomponent μ-star polymers. Using this methodology, both the arm introduction and DOL reintroduction steps are simultaneously performed by the linking reaction of the DOL-end-functionalized polymer anion with the formyl group regenerated from the DOL reintroduced in advance and repeated several times. By combining the DOL-end-functionalized polymer anions with non-DOL-functionalized polymer anions in the linking reaction, synthetically-difficult and well-defined complex μ-star polymers ranging from the ABC, ABCD, ABCDE, and ABCD₂, to the ABCD₂E₂ types were successfully obtained. Moreover, synthesis of A₃B₂ and A₃B₂C₄ star polymers was also achieved with the same methodology using (DOL)₂-end-functionalized polymer anions. The arm segments were polystyrene, polystyrene derivatives, polyisoprene, poly(2-vinylpyridine), and poly(alkyl methacrylate(s)), which were introduced into the μ-star polymers via the formyl or α-phenylacrylate reaction site(s).