The chemistry of poly(2-oxazoline)s

As we celebrate the 50th birthday of the discovery of poly(2-alkyl/aryl-2-oxazoline)s (PAOx) this year we see a research field that is rapidly expanding after some lesser academic activity in the nineties. This renewed interest in PAOx stems from the fact that this polymer class combines high synthetic versatility with good biocompatibility, opening up the way to highly functional (biocompatible) materials. PAOx are prepared by living cationic ring-opening polymerization (CROP) of 2-oxazolines, which will be the in-depth focus off this review. The variety of 2-oxazoline monomers that are readily available or can easily be synthesized, allows for tuning of polymer properties and introduction of diverse functionalities as well as provides access to different polymer architectures. Moreover, thanks to the living nature of the CROP, well-defined polymers with narrow molar mass distribution and high end-group fidelity can be obtained.