Controlled star poly(2-oxazoline)s: Synthesis, characterization

Abstract Poly(2-methyl-2-oxazoline) and poly(2-ethyl-2-oxazoline) star polymers with 3, 4 and 6 arms are synthesized from pluritriflate initiators. Characterization of the topology was achieved by NMR, SEC and kinetic studies. The initiation step of 2-ethyl-2-oxazoline being slow, heterogeneous star polymers in arm molar masses are obtained for low molar mass polymers. However, for both monomers, high molar mass homogeneous star polymers are obtained. A fast initiation is observed for the polymerization of 2-methyl-2-oxazoline, providing a control of the topology even at low molar mass. In the studied molar mass range, linear kinetic first order plots and linear molar mass as a function of conversion are obtained for both monomers, suggesting living polymerizations.