Multiarm star block and multiarm star mixed-block copolymers via azide-alkyne click reaction

The synthesis of multiarm star block (and mixedblock) copolymers are efficiently prepared by using Cu(I) catalyzed azide-alkyne click reaction and the arm-first approach. α-Silyl protected alkyne polystyrene (α-silyl-alkyne-PS) was prepared by ATRP of styrene (St) and used as macroinitiator in a crosslinking reaction with divinyl benzene to successfully give multiarm star homopolymer with alkyne periphery. Linear azide end-functionallzed polyethylene glycol) (PEG-N₃) and poly (fert-butyl acrylate) (PtBA-N₃) were simply clicked with the multiarm star polymer described earlier to form star block or mixed-block copolymers in N,N-dîmethyl formamide at room temperature for 24 h. Obtained multiarm star block and mixedblock copolymers were identified by using ¹H NMR, GPC, triple detection-GPC, atomic force microscopy, and dynamic light scattering measurements.