Multiarm star block copolymers via diels-alder click reaction

Two types of multiarm star block copolymers: (polystyrene) _m-poly(divinyl-benzene)-poly(methyl methacrylate)_n, (PS)_m-polyDVB-(PMMA)_n and (polystyrene) _m-poly(divinylbenzene)-poly(tert-butyl acrylate)_k, (PS)_m-polyDVB-(PtBA)_k were successfully prepared via a combination of cross-linking and Diels-Alder click reactions based on "arm-first" methodology. For this purpose, multiarm star polymer with anthracene functionality as reactive periphery groups was prepared by a cross-linking reaction of divinyl benzene using α-anthracene end functionalized polystyrene (PS-Anth) as a macroinitiator. Thus, obtained multiarm star polymer was then reacted with furan protected maleimide-end functionalized polymers: PMMA-MI or PtBA-MI at reflux temperature of toluene for 48 h resulting in the corresponding multiarm star block copolymers via Diels-Alder click reaction. The multiarm star and multi-arm star block copolymers were characterized by using ¹H NMR, SEC, Viscotek triple detection SEC (TD-SEC) and UV.