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Defined High Molar Mass Poly(2‐Oxazoline)s
Author(s) -
Monnery Bryn D.,
Jerca Valentin V.,
Sedlacek Ondrej,
Verbraeken Bart,
Cavill Rachel,
Hoogenboom Richard
Publication year - 2018
Publication title -
angewandte chemie international edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.831
H-Index - 550
eISSN - 1521-3773
pISSN - 1433-7851
DOI - 10.1002/anie.201807796
Subject(s) - molar mass , oxazoline , dispersity , chain transfer , chemistry , polymer chemistry , copolymer , chain (unit) , polymer , living polymerization , molecular mass , polymerization , alkyl , molar mass distribution , molar ratio , radical polymerization , organic chemistry , catalysis , enzyme , physics , astronomy
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 ( Ð ) <1.05) and defined polymers up to at least 300 kDa ( Ð <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.