End-functionalized diblock copolymers by mix and match of poly(2-oxazoline) and polyester building blocks

Stafast, Leanne M.; Engel, N.; Görls, Helmar; Weber, C.; Schubert, Ulrich S.

doi:10.1016/j.eurpolymj.2022.111779

Cited by 6 publications

(3 citation statements)

References 55 publications

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“…However, some of them tend to cause slow initiation, which can lead to multimodal molar mass distributions for multifunctional initiators . The use of iodine-based initiators can circumvent that problem, besides enhancing the polymerization rate compared to the corresponding bromine-based initiators. ,− Therefore, two initiators based on iodomethylbenzene derivatives were synthesized via Finkelstein reactions in order to obtain symmetrical two- and three-armed cross-linkers (Scheme ). The corresponding bi- and trifunctional initiators 1,4-bis(iodomethyl)benzene ( BIB ) and 1,3,5-tris(iodomethyl)benzene ( TIB ), respectively, were obtained according to the literature. , However, TIB has not been used as an initiator for the CROP of 2-alkyl-2-oxazolines to the best of our knowledge.…”

Section: Resultsmentioning

confidence: 99%

Cryogels Based on Poly(2-oxazoline)s through Development of Bi- and Trifunctional Cross-Linkers Incorporating End Groups with Adjustable Stability

Engel,

Hoffmann,

Behrendt

et al. 2024

Macromolecules

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1,4-Bis(iodomethyl)benzene and 1,3,5-tris-(iodomethyl)benzene were used as initiators for the cationic ringopening polymerization (CROP) of 2-ethyl-2-oxazoline (EtOx) and its copolymerization with tert-butyl (3-(4,5-dihydrooxazol-2yl)propyl)carbamate (BocOx) or methyl 3-(4,5-dihydrooxazol-2yl)propanoate (MestOx). Kinetic studies confirmed the applicability of these initiators. Termination with suitable nucleophiles resulted in two-and three-armed cross-linkers featuring acrylate, methacrylate, piperazine-acrylamide, and piperazine-methacrylamide as polymerizable ω-end groups. Matrix-assisted laser desorption/ionization mass spectrometry and nuclear magnetic resonance (NMR) spectroscopy confirmed the successful attachment of the respective ω-end groups at all initiation sites for every prepared cross-linkers. Except for acrylate, each ω-end group remained stable during deprotection of BocOx containing cross-linkers. The cryogels were prepared using EtOx-based cross-linkers, as confirmed by solid-state NMR spectroscopy, scanning electron microscopy, and thermogravimetric analysis. Stability tests revealed a complete dissolution of the acrylate-containing gels at pH = 14, whereas the piperazine-acrylamide-based cryogels featured excellent hydrolytic stability.

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Section: Resultsmentioning

confidence: 99%

Cryogels Based on Poly(2-oxazoline)s through Development of Bi- and Trifunctional Cross-Linkers Incorporating End Groups with Adjustable Stability

Engel,

Hoffmann,

Behrendt

et al. 2024

Macromolecules

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“…Poly( l -lactic acid) was synthesized via 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene (mTBD) catalyzed ring-opening polymerization from l -lactide (LA) initiated by BCN-OH as described in our recent publication. 21…”

Section: Methodsmentioning

confidence: 99%

“…7 †). 21 A library of fourteen block copolymers was synthesized via SPAAC using the PEtOx-N 3 , the six dPAOx and the two polyester building blocks as presented in Fig. 1.…”

Section: Synthesis Of the Amphiphilic Block Copolymers From Dpmeox-n ...mentioning

confidence: 99%

How introduction of hydrolyzable moieties in POx influences particle formation – a library approach based on block copolymers comprising polyesters

Göppert,

Vollrath,

Stafast

et al. 2024

RSC Appl. Polym.

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Cyclooctyne End‐Functionalized Poly(morpholine‐2,5‐dione)s

Schreiber,

Göppert,

Stafast

et al. 2024

Macromol. Rapid Commun.

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The cyclooctyne‐functionalized alcohol (1R,8S,9S)‐bicyclo‐[6.1.0]non‐4‐yn‐9‐ylmethanol (BCN‐OH) is applied as initiator for the organo‐catalyzed ring‐opening polymerization (ROP) of morpholine‐2,5‐diones based on the l‐amino acids valine, isoleucine, and phenylalanine. The ROP is catalyzed by a binary system of 1,8‐diazabicyclo[5.4.0]undec‐7‐ene (DBU) and 1‐(3,5‐bis(trifluoromethyl)phenyl)‐3‐cyclohexylthiourea (TU) applying a feed ratio of [M]/[I]/[DBU]/[TU] of 100/1/1/10. Kinetic studies reveal that BCN‐OH is capable to initiate the polymerization of morpholine‐2,5‐diones, which proceed in a controlled manner until monomer conversions of 80%. Characterization by means of 1H NMR spectroscopy, size exclusion chromatography (SEC), and matrix‐assisted laser desorption/ionization‐time of flight‐mass spectrometry confirm the covalent attachment of the cyclooctyne moiety as α‐end group of the poly(morpholine‐2,5‐dione)s with maximum dispersities of 1.25. As a proof of concept, a vitamin A end‐functionalized poly(2‐ethyl‐2‐oxazoline) is coupled to a poly(ester amide) by strain‐promoted azide‐alkyne cycloaddition. Characterization of the block copolymer by SEC and DOSY NMR spectroscopy confirm the successful attachment of the two building blocks. The versatile cyclooctyne moiety shall facilitate a metal‐free attachment of other polymer blocks, targeting ligands or dyes at the α‐end group of well‐defined poly(morpholine‐2,5‐dione)s. In consequence, the approach provides access to a new generation of functionalized poly(ester amide)s, which can be customized for specific needs.

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End-functionalized diblock copolymers by mix and match of poly(2-oxazoline) and polyester building blocks

Cited by 6 publications

References 55 publications

Cryogels Based on Poly(2-oxazoline)s through Development of Bi- and Trifunctional Cross-Linkers Incorporating End Groups with Adjustable Stability

Cryogels Based on Poly(2-oxazoline)s through Development of Bi- and Trifunctional Cross-Linkers Incorporating End Groups with Adjustable Stability

How introduction of hydrolyzable moieties in POx influences particle formation – a library approach based on block copolymers comprising polyesters

Cyclooctyne End‐Functionalized Poly(morpholine‐2,5‐dione)s

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