Abstract
Poly(2-alkyl-2-oxazoline)s (PAOx) are regaining interest for biomedical applications. However, their 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 (D) <1.05) and defined polymers up to at least 300 kDa (D <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-ethyl2- oxazoline and 2-methoxycarbonylethyl-2-oxazoline.
Original language | English |
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Pages (from-to) | 15400-15404 |
Number of pages | 5 |
Journal | Angewandte Chemie-International Edition |
Volume | 57 |
Issue number | 47 |
Early online date | 10 Oct 2018 |
DOIs | |
Publication status | Published - 19 Nov 2018 |
Keywords
- cationic polymerisation
- polymers
- ring-opening polymerisation
- tautomerisation
- CYCLIC IMINO ETHERS
- POLY(2-ETHYL-2-OXAZOLINE) NANODOTS
- SOLAR-CELLS
- POLYMERIZATION
- TEMPERATURE
- 2-METHYL-2-OXAZOLINE
- MACROMONOMERS
- TELECHELICS