Functional 2-oxazolines for the synthesis of graft copolymers

The increasing attention of poly(2-oxazoline)s both in biological and industrial applications has led to a plethora of research on this very interesting polymer class. The aim of this work is to synthesise poly(2-oxazoline) based graft copolymers by combination of cationic ring opening polymerisation (CROP) and reversible deactivation radical polymerisation (RDRP) via the grafting from approach. This was realised by utilising a hydroxyl functionalised 2-oxazoline monomer derived from ε-caprolactone. Firstly, the combination of CROP and Cu-mediated RDRP is explored to synthesise graft copolymers containing a poly(2-oxazoline) backbone with acrylate-based grafts that are soluble in oil. These graft copolymers are then tested for their friction modifying properties in oil for the ultimate purpose of being formulated into oil additive packages. Then, the combination of CROP and reversible addition-fragmentation chain transfer (RAFT) polymerisation is shown by functionalising the hydroxyl group containing 2-oxazoline monomer with a chain transfer agent; the use of RAFT polymerisation on the grafts allowing for a metal free approach with a wider monomer scope. Finally, the synthesis of hydrophilic poly(2-oxazoline)s is discussed, whereby the hydroxyl functional group of the 2- oxazoline monomer is protected during CROP and subsequently deprotected to reveal a poly(2-oxazoline) chain with pendant hydroxyl groups. The hydrophilicity and thermoresponsive properties of the hydroxyl containing poly(2-oxazoline)s is discussed.