Synthesis of functionalized NMP initiators for click chemistry: A versatile method for the preparation of functionalized polymers and block copolymers

A novel NMP initiator functionalized with an alkyne group was synthesized and its polymerization behavior investigated. It was shown that the synthesized alkyne end-functionalized polymers exhibit a linear relationship between calculated number-averaged molecular weight and the experimental one and are characterized by a narrow molecular weight distribution. In contrast, azido end-functionalized polymers were obtained in polymer analogue reactions. Furthermore, the alkyne end-functionalized polymers were reacted at room temperature with different azides to introduce several functional groups. It could be shown that the polymers can be efficiently and smoothly multimodified using the Cu(I)-catalyzed 1,3-dipolar cycloaddition reaction between azides and alkynes (click chemistry), thus yielding macromolecules with defined molecular architecture and functionality. Furthermore, the synthesis of diblock copolymers by combining predefined polymeric fragments via click chemistry is demonstrated. In this case, the fragments could be completely linked with each other and the diblock copolymers obtained showed a narrow molecular weight distribution. [GRAPHICS] content, spacer chain length of the glycomonomer, and the chain architecture of the copolymers. Especially by the block copolymer concept, glycopolymers with lower critical solution temperatures (LCSTs) in the physiologically interesting range could be realized. [GRAPHICS]