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

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

“…The attributions of the peaks were confirmed thanks to 2D NMR. Quantitative reactions were confirmed by the total absence of signals belonging to the methylene groups CH 2 -OH in 1 H NMR and in 13 C NMR, and the presence of the expected peaks in HRMS-ESI.…”

“…1,1,1-tris(hydroxymethyl)ethane tristriflate (I 3 ) and pentaerythritol tetratriflate (I 4 ) were synthesized according to literature [33]. Furthermore, an additional tetrafunctional molecule, di(trimethylolpropane) tetratriflate (I e4 ) and an hexafunctional molecule, dipentaerythritol hexatriflate (I e6 ), were synthesized by adapting literature procedure [33] and were characterized by 1 H, 13 C, 2D NMR and high resolution electrospray ionization mass spectrometry (HRMS-ESI). Di (trimethylolpropane) tetratriflate (I e4 ) and dipentaerythritol hexatriflate (I e6 ) present an ether bond in their core and so "e" stand for "ether" in their respective abbreviation.…”

“…The versatile 2-alkyl-2-oxazoline polymerization chemistry allows the synthesis of complex architectures such as block copolymers [11][12][13], star-shaped [14][15][16] or hyperbranched [17][18][19] polymers. Star polymers are composed of at least three linear arms spreading from a low molecular weight central core.…”

Biocompatible Soft Nanoparticles with Multiple Morphologies Obtained from Nanoprecipitation of Amphiphilic Graft Copolymers in a Backbone-Selective Solvent

“…Furthermore, poly­(2-alkyl-2-oxazoline)­s are attracting growing interest because of their highly tunable structure, versatile properties, and favorable biological safety profiles compared to poly­(ethylene glycol) (PEG). − The presence of PEG is of particular interest, as PEG-functionalized polymers can be used in aqueous media, are resistant to protein adsorption, and exhibit enhanced residence time in delivery applications. , However, over the past few years, several studies showed important disadvantages of PEG. , Because of the intensive use of PEG, the PEGylated systems have lost their desirable properties when applied in vivo , due to the existence of specific and nonspecific recognition by the immune system. − Thanks to its hydrophilicity, biocompatibility, stealth behavior, and biodistribution, PMeOx offers nearly the same beneficial properties as PEG and is a potential alternative to PEG for use in biomedical applications. ,, Poly­(2-alkyl-2-oxazoline)­s are accessible via living cationic ring-opening polymerization of 2-alkyl-2-oxazoline, which allows incorporation of various functionalities in the polymer. Recently, we reported on the synthesis of a thermoresponsive copolymer, poly­(2-methyl-2-oxazoline- co -2-(5-azidopentyl)-2-oxazoline) (P­(MeOx- co -N 3 PentOx)), bearing pendant azido groups on the macromolecular chain. , This azido copolymer can be coupled to alkyne end-functionalized PLA by the grafting-onto approach through the Huisgen 1,3-dipolar cycloaddition reaction to prepare graft copolymers composed of a hydrophilic backbone and hydrophobic grafts …”

Multireactive Poly(2-oxazoline) Nanofibers through Electrospinning with Crosslinking on the Fly

“…In recent years, poly­(2-alkyl-2-oxazoline)­s (PAOx), tertiary amide analogues of polypeptides, obtained using cationic ring-opening polymerization of the 2-oxazoline monomers have emerged as an important class of polymers suitable for various biomedical applications due to their resemblance to poly­(ethylene glycol)­s with regard to biocompatibility and “stealth” behavior. − Utilization of “clickable” functional group bearing initiators and monomers provides well-defined copolymers that can undergo both side chain and end group functionalization. − Among the various available “click”-type transformations, the radical thiol–ene reaction has been extensively employed due to its mild and metal catalyst-free conditions. , Thiol–ene chemistry in combination with PAOx was first reported by Schlaad and co-workers, after which it has become a popular tool as the ene-group can be introduced in the monomer and does not interfere with the living cationic ring-opening polymerization. − Among the limited number of reports on PAOx-based nanofibers, electrospinning of poly­(2-ethyl-2-oxazoline) (PEtOx) was reported by Iruin and co-workers to obtain noncrosslinked nanofibers . Also, composite nanofibers were obtained by electrospinning an aqueous solution of PEtOx and Co­(CH 3 COO) 2 ·4H 2 O, which were then calcined to yield ceramic nanofibers .…”