Polymerizing Base Sensitive Cyclic Carbonates Using Acid Catalysis

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• 作者：Daniel J. Coady ; Hans W. Horn ; Gavin O. Jones ; Haritz Sardon ; Amanda C. Engler ; Robert M. Waymouth ; Julia E. Rice ; Yi Yan Yang ; James L. Hedrick
• 刊名：ACS Macro Letters
• 出版年：2013
• 出版时间：April 16, 2013
• 年：2013
• 卷：2
• 期：4
• 页码：306-312
• 全文大小：449K
• 年卷期：v.2,no.4(April 16, 2013)
• ISSN：2161-1653

文摘

Organic acids were explored as a means to expand the library of cyclic carbonate monomers capable of undergoing controlled ring-opening polymerization. Various nitrogenous bases have proven incredibly adept at polymerizing cyclic carbonates; however, their use has largely precluded monomers with an acidic proton. Molecular modeling of acid catalysis provided new mechanistic insight, wherein a bifunctional activation pathway was calculated. Depending on acid structure, modeling experiments showed both monomer carbonyls and propagating hydroxyl groups undergo hydrogen bonding activation. The dual activation mechanism suggests acid strength, as well as conjugate base effects, play vital roles in catalyzing cyclic carbonate polymerizations. Moreover, the use of acid catalysis was shown to be compatible with amide-containing monomers while promoting controlled polymerizations.