Synthesis of poly(2-ethyl-2-oxazoline)-b-poly(ε-caprolactone) conjugates by a new modular strategy

Abstract: Amphiphilic block copolymers where hydrophobicity and hydrophilicity coincide are essential building blocks for many supramolecular systems. By this time, polyethylene glycol (PEG) has been a conventional choice to constitute hydrophilicity; however, it suffers from certain drawbacks, severely limiting its use in these compounds. To date, one potential modality to overcome this complication is to utilize poly(2-ethyl-2-oxazoline) (PEtOx) instead, given that this also-hydrophilic polymer is very comparable to PEG, in many ways. In this regard, amphiphilic block copolymers harboring PEtOx and synthetic approaches to access these polymeric materials have been documented in the literature. Within this scope, we crafted a modular approach for the synthesis of poly(2-ethyl-2-oxazoline)-b-poly(ε-caprolactone) to govern its molecular structure. Herein, we extend this work and report a novel poly(2-ethyl-2-oxazoline)-b-poly(ε-caprolactone) derivative with electrophilic moiety on terminal position. We believe that this novel design could lead up to expeditious synthesis of block copolymer-biomolecule conjugates, which are of paramount significance for many applications. Graphic abstract: [Figure not available: see fulltext.].