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Zwitterionic Copolymerization: Synthesis of Cyclic Gradient Copolymers
Author(s) -
Shin Eun Ji,
Brown Hayley A.,
Gonzalez Silvia,
Jeong Wonhee,
Hedrick James L.,
Waymouth Robert M.
Publication year - 2011
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.201101853
Subject(s) - copolymer , macromolecule , polymer , polymer chemistry , chemistry , scheme (mathematics) , computer science , polymer science , combinatorial chemistry , materials science , organic chemistry , mathematics , biochemistry , mathematical analysis
How to get rich fast : The zwitterionic copolymerization of δ‐valerolactone (VL) and ε‐caprolactone (CL) provides an expedient route to cyclic gradient copolymers. The faster ring‐opening of VL relative to CL with N‐heterocyclic carbenes, coupled with sufficiently long lifetimes of the growing zwitterions leads to a polymer structure comprised of VL‐rich sequences that transition to CL‐rich sequences in a cyclic macromolecule (see scheme).