Dynamic Covalent Diblock Copolymers Prepared from RAFT Generated Aldehyde and Alkoxyamine End-Functionalized Polymers

Aldehyde- or alkoxyamine-containing trithiocarbonate chain transfer agents were prepared and used to mediate the synthesis of a series of polymers end-functionlized with either aldehyde or alkoxyamines functions, utilizing reversible addition−fragmentation polymerization techniques. Aldehyde end-functionalized polymers were shown to link through reversible oxime bond formation with alkoxyamine end-funtionalized polymers forming diblock copolymers. The dynamic nature of the oxime bond linking these polymer blocks together was demonstrated through a simple exchange reaction with a small molecule alkoxyamine. A diblock copolymer prepared from the self-assembly of an aldehyde end-functionalized polyisoprene with an alkoxyamine end-functionalized polystyrene was shown to undergo further hierarchical self-assembly into micellar aggregates in DMF. It was shown that the addition of an excess of a small molecule alkoxyamine triggered the disassembly of these micelles.