Novel Investigations on Kinetics and Polymerization Mechanism of Oxazolines Initiated by Iodine

The cationic ring-opening polymerization of 2-methyl-2-oxazoline ( MOx ) using iodine initiating system was reported. Uncolored polyoxazolines were produced in spite of the use of iodine initiator, well-known dye molecule. Low molecular weight asymmetric telechelic polyoxazolines carrying an acetylimine headgroup and an oxazolinium end group were synthesized, with a good control over the molecular weight. NMR and MALDI−TOF experiments allowed the full determination of the chemical structures of the produced poly(2-methyl-2-oxazoline)s, notably with the acetylimine headgroup, explained by spontaneous α-HI elimination. Finally, to our knowledge, we reported the first detailed mechanism of cationic ring-opening polymerization of 2-methyl-2-oxazoline in acetonitrile according to UV experiments. An ionic-type mechanism was involved with the dissociation of molecular iodine to active initiating species.