A New Associative Diblock Copolymer of Poly(ethylene glycol) and Dense 1,2,3‐Triazole Blocks: Self‐Association Behavior and Thermoresponsiveness in Water

In this work, new diblock copolymers of poly(ethylene glycol) (PEG) and dense 1,2,3‐triazole blocks (EGm‐b‐APn and EGm‐b‐ABn, where m and n denote the degrees of polymerization), are synthesized by copper(I)‐catalyzed azide–alkyne cycloaddition polymerization of 3‐azido‐1‐propyne (AP) and 3‐azido‐1‐butyne (AB), respectively, in the presence of PEG possessing a propargyl group. Their self‐association behavior and thermoresponsive property in water are investigated. The characterization data indicate that EG45‐b‐AP6 and EG45‐b‐AP14 form dominantly spherical micelles, EG18‐b‐AP4 and EG18‐b‐AP10 form vesicles, and EG18‐b‐AB7 forms rodlike micelles. Aqueous solutions of EG18‐b‐AP10, EG45‐b‐AP14, and EG18‐b‐AB7 undergo lower critical solution temperature (LCST)‐type phase separation. The thermoresponsive association behavior can be controlled by adjusting the ratio of block lengths and by attaching methyl substituents. In this work, new diblock copolymers of poly(ethylene glycol) (PEG) and dense 1,2,3‐triazole blocks (EGm‐b‐APn and EGm‐b‐ABn), are synthesized by copper(I)‐catalyzed azide–alkyne cycloaddition polymerization. Their self‐association behavior and thermoresponsive property in water are investigated. The thermoresponsive association behavior can be controlled by adjusting the ratio of block lengths and by attaching methyl substituents.