Easy Access to Amphiphilic Heterografted Poly(2-oxazoline) Comb Copolymers

A series of heterografted polymers with a polymethacrylate backbone and varying composition of oligomeric 2-oxazoline side chains was synthesized by copolymerization of oligo(2-ethyl-2-oxazoline)methacrylate and oligo(2-n-nonyl-2-oxazoline)methacrylate (ONonOx) macromonomers using the reversible addition–fragmentation chain transfer (RAFT) technique. Kinetic studies revealed pseudofirst order kinetics, PDI values below 1.3, and a slight enrichment of ONonOx side chains toward the end of the reaction. The heterografted comb polymers were characterized by means of 1H NMR spectroscopy (0 to 100 mol % ONonOx) and size exclusion chromatography. Differential scanning calorimetry and wide-angle X-ray scattering revealed partial crystallinity of the lateral n-nonyl chains within the ONonOx domains. Depending on the composition of the amphiphilic copolymer, the comb polymers either formed unimers or aggregated (super)structures in water, methanol, and ethanol, as investigated by dynamic light scattering and cryo-transmission electron microscopy.