Poly(2-ethyl-2-oxazoline)-block-polycarbonate block copolymers: from improved end-group control in poly(2-oxazoline)s to chain extension with aliphatic polycarbonate through a fully metal-free ring-opening polymerisation process

Victor De La Rosa, Sarah Tempelaar, Philippe Dubois, Richard Hoogenboom, Laetitia Mespouille.


Block copolymer micelles hold great promise for developing next generation drug delivery vehicles to improve therapeutics. In this work, the biocompatibility of poly(2-alkyl-2-oxazoline)s (PAOx) was combined with the biodegradability and biocompatibility of aliphatic polycarbonates through the preparation of block copolymers. These well-defined blocks were prepared via cationic ring-opening polymerisation (CROP) of 2-oxazolines followed by the organocatalytic ring-opening polymerisation (ROP) of cyclic carbonate monomers. The improved synthesis of hydroxyl terminated poly(2-ethyl-2-oxazoline)s (PEtOx-OH) is reported allowing high end-group fidelity. These polymers were used as macroinitiators in the controlled ROP of various cyclic carbonate monomers (TMC and benzyl, allyl, propargyl, bromide and morpholino functional monomers) resulting in well-defined amphiphilic block copolymers.