期刊
JOURNAL OF COMPUTATIONAL CHEMISTRY
卷 38, 期 14, 页码 1093-1102出版社
WILEY
DOI: 10.1002/jcc.24779
关键词
epoxy curing mechanism; epoxy-carboxylic acid reaction; density functional theory; reaction mechanism; polymer chemistry
资金
- Dow Chemical Company
- Institute for Computational Science and Technology via Ho-Chi-Minh City Office of Science and Technology, Vietnam
- Vietnam's Ministry of Education
A comprehensive picture on the mechanism of the epoxy-carboxylic acid curing reactions is presented using the density functional theory B3LYP/6-31G(d,p) and simplified physical molecular models to examine all possible reaction pathways. Carboxylic acid can act as its own promoter by using the OH group of an additional acid molecule to stabilize the transition states, and thus lower the rate-limiting barriers by 45 kJ/mol. For comparison, in the uncatalyzed reaction, an epoxy ring is opened by a phenol with an apparent barrier of about 107 kJ/mol. In catalyzed reaction, catalysts facilitate the epoxy ring opening prior to curing that lowers the apparent barriers by 35 kJ/mol. However, this can be competed in highly basic catalysts such as amine-based catalysts, where catalysts can enhance the nucleophilicity of the acid by forming hydrogen-bonded complex with it. Our theoretical results predict the activation energy in the range of 71 to 94 kJ/mol, which agrees well with the reported experimental range for catalyzed reactions. (c) 2017 Wiley Periodicals, Inc.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据