SG1-based alkoxyamine bearing a N-succinimidyl ester: A versatile tool for advanced polymer synthesis

This paper reports the preparation of a MAMA-SG1 (BlocBuilder™) derived alkoxyamine bearing a N-succinimidyl (NHS) ester group 1, valuable for functional and advanced polymer synthesis. This alkoxyamine was exploited following two strategies: (i) a post-functionalization approach based on the transformation of α-NHS chain ends of polymers previously obtained by nitroxide mediated polymerization (NMP) from 1 (path A) and (ii) a pre-functionalization approach based on the functionalization of alkoxyamine 1 prior to NMP (path B). Path A was demonstrated by derivatization of α-NHS functionalized polystyrenes with ethanolamine, yielding hydroxyl-functionalized polystyrenes. Path B was illustrated by two examples: first, a OH functional alkoxyamine initiator, prepared by reaction of 1 with ethanolamine, was used for the synthesis of polystyrene-b-poly(d,l-lactide) by combining NMP and ring-opening polymerization. Secondly, a poly(propylene oxide)–SG1 macroalkoxyamine, obtained from reaction of 1 with NH2-functionalized poly(propylene oxide), was used as a macroinitiator for NMP of styrene to obtain a PS-b-PPO block copolymer.