Development of a new azido-oxazoline monomer for the preparation of amphiphilic graft copolymers by combination of cationic ring-opening polymerization and click chemistry

Copolymers based on azidopentyl-2-oxazoline: Synthesis, characterization and LCST behavior

“…Diethyl ether and dichloromethane were purchased from Carlo Erba and used without further purification. The monomers 2-(5-azidopentyl)-2-oxazoline (prepared in the laboratory according the procedure described previously [35]) and 2-methyl-2-oxazoline (Aldrich, Milwaukee WI, USA, purity 99%) were dried overnight over calcium hydride and purified by distillation under an argon atmosphere. Poly(2-(5-azidopentyl)-2-oxazoline) was prepared by CROP applying a similar protocol as reported previously [35].…”

“…The monomers 2-(5-azidopentyl)-2-oxazoline (prepared in the laboratory according the procedure described previously [35]) and 2-methyl-2-oxazoline (Aldrich, Milwaukee WI, USA, purity 99%) were dried overnight over calcium hydride and purified by distillation under an argon atmosphere. Poly(2-(5-azidopentyl)-2-oxazoline) was prepared by CROP applying a similar protocol as reported previously [35]. For example, the preparation of Entry 1 ( Table 1) was performed as follows: 2-(5-azidopentyl)-2-oxazoline (2 mL, 11.8 mmol) was polymerized in dry acetonitrile (6 mL) by initiation with 1-iodobutane (61 lL, 0.54 mmol).…”

“…The synthesis of the 2-(5-azidopentyl)-2-oxazoline was reported in a previous work [35]. The poly(2-(5-azidopentyl)-2-oxazoline) (PN 3 PentOx) was synthesized by cationic ring-opening polymerization (CROP) of 2-(5-azidopentyl-2-oxazoline) initiated by an alkyl iodide, 1-iodobutane (Scheme 1).…”

“…The azido-function of the polymers has the ability to generate new graft copolymers using the grafting-onto approach through copper-catalyzed azide-alkyne cycloaddition [34]. A feasibility study of graft copolymer synthesis was reported in a previous work [35]. The originality and novelty of the current contribution is divided in two aspects.…”

Acyl guanidine functional poly(2‐oxazoline)s as reactive intermediates and stimuli‐responsive materials

“…Within most of these applications, postpolymerization modification reactions play a central role in the synthesis of functional polymers, enabling to overcome the limitations of the cationic ring‐opening polymerization (CROP). By utilizing CROP‐compatible functional groups, such as alkenes, alkynes, unactivated esters, azides, or thiocarbamate groups, a wide selection of functional molecules can be introduced onto the polymer chain, and if needed, in an orthogonal fashion . Within this set of functional moieties, ester functional PAOx are particularly interesting, due to their versatile functionalization opportunities, that is, transesterification and amidation, and their utility as a cleavable linker or a precursor for hydrazone bonds .…”