We report the cationic ring-opening polymerization of 2-methyl-2-oxazoline (MOx) using bio-based initiator (GCTs). The functional initiator GCTs was prepared by tosylation of the corresponding alcohol glycerol carbonate (GC) The termination stage of the polymerization was achieved in presence of KOH and the telechelic polyoxazoline carrying five-membered cyclic carbonate and oxazolium end groups (GC-POx(ium)) was converted to ((HO)(2)-POx-OH) carrying alpha-diol and omega-hydroxyl groups. End-functionalized polyoxazolines (HO)(2)-POx-OH with M ranging from 4200 to 8400 g mol(-1) were synthesized According to GPC results, the polymerizations of MOx using GCTs and other initiator coming from 1,2-isopropylidene-glycerol (Solk-Ts) were compared. On the basis of FTIR and NMR spectroscopes, the chemical modification of end chains of polyoxazolines was investigated by two alternative synthetic routes. The isocyanate route is a postpolymerization urethanization The nucleophilic reactivity of the alpha-diol and omega-hydroxyl groups of (HO)(2)-POx-OH was studied with functional isocyanate (TESPI) In the carbonate route, the electrophilic reactivity of alpha- and omega-end groups of GC-POx(ium) were explored with amine It was demonstrated that during the termination stage of the polymerization in presence of allylamine both urethane linker in s-end chain was synthesized and the omega-oxazolium group was converted into terminal amine. The carbonate route is an alternative to synthesize urethane without isocyanate. (C) 2010 Wiley Periodicals, Inc J Polym Sci Part A Polym Chem 48 4027-4035, 2010