N-heterocyclic carbenes as organocatalysts in controlled/living ring-opening polymerization of O-carboxyanhydrides derived from l -lactic acid and l -mandelic acid.

Autor: Xia, Haidong, Kan, Suli, Li, Zhenjiang, Chen, Jia, Cui, Saide, Wu, Wenzhuo, Ouyang, Pingkai, Guo, Kai
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Zdroj: Journal of Polymer Science. Part A, Polymer Chemistry; Aug2014, Vol. 52 Issue 16, p2306-2315, 10p
Abstrakt: ABSTRACT An organocatalytic approach to controlled/living ring-opening polymerizations (ROPs) of O-carboxyanhydrides (OCAs) using N-heterocyclic carbenes (NHCs) as nucleophilic catalysts has been investigated. NHCs with different structures were used in order to compare the catalytic performances in the ROP of OCA of l-lactic acid. 1H NMR, SEC, and MALDI-TOF MS measurements of the products clearly indicated a controlled/living manner of the polymerization. The controlled/living nature was further confirmed by kinetic and chain extension experiments. Additionally, polylol initiators were used to produce α,ω-dihydroxy telechelic, 3-, and 4-armed star-shaped polymers. Moreover, star-shaped diblock copolymer, bearing methyl and phenyl side groups, has been successfully synthesized with OCA/NHC system. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014. 52, 2306-2315 [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index
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