Defined High Molar Mass Poly(2‐Oxazoline)s

Abstract

Poly(2-alkyl-2-oxazoline)s (PAOx) are regaining interest for biomedical applications.H owever,t heir full potential is hampered by the inability to synthesise uniform high-molar mass PAOx. In this work, we proposed alternative intrinsic chain transfer mechanisms based on 2-oxazoline and oxazolinium chain-end tautomerisation and derived improved polymerization conditions to suppress chain transfer,allowing the synthesis of highly defined poly(2-ethyl-2-oxazoline)s up to ca. 50 kDa (dispersity () < 1.05) and defined polymers up to at least 300 kDa ( < 1.2). The determination of the chain transfer constants for the polymerisations hinted towards the tautomerisation of the oxazolinium chain end as most plausible cause for chain transfer.Finally,the method was applied for the preparation of up to 60 kDa molar mass copolymers of 2-ethyl-2-oxazoline and 2-methoxycarbonylethyl-2-oxazoline.

Poly(2‐Oxazoline)‐Based Functional Peptide Mimics: Eradicating MRSA Infections and Persisters while Alleviating Antimicrobial Resistance

“…The controllable polymerization gave Gly‐POX in narrow dispersity ( Đ =1.07–1.23) and at variable chain lengths ranging from 6 to 40mers (Figure c; see Figures S6–S13 and Table S1). A tailing was observed on the GPC trace of the polymer with DP=40, which indicated possible chain‐transfer side reactions and is in line with the observation in literature on the synthesis of POX . Initial antibacterial studies showed that Gly‐POX displayed potent and polymer length dependent activity against Staphylococcus aureus ( S. aureus ), with an MIC (the minimum inhibitory concentration) in the range of 12.5–50 μg mL −1 .…”

Controlling nanoemulsion surface chemistry with poly(2-oxazoline) amphiphiles

“…Acrylic acid termination was found to be quantitative for polymers 6-9 (ESI, p. S57-S60), while 10 and 11 (ESI, p. S61-S62) were hydroxylterminated due to extended reaction times. The extended reaction times may also lead to chain transfer and chain coupling side reactions 87,88. c Dispersity index (Đ) determined by SEC analysis (eluent: DMF + 0.1 M LiBr).…”

Living Polymerization of 2-Ethylthio-2-oxazoline and Postpolymerization Diversification

“…The small high-molecular weight shoulder and low-molecular weight tail in the SEC trace of the diblock copolymer (Figure 4b, purple) are likely due to chain coupling and transfer processes known to occur in the polymerization of 2-ethyl-2-oxazoline. 36 Subsequently, the same procedure was employed for the activation of the thiocarbamate groups in the block polymer ( P6 ), followed by substitution with benzylamine ( P7 , Figure 4a). Using this mild method, the amide groups were unaffected while additional functionalities were installed, as confirmed by NMR (Figures S57–S62).…”